Orthopedic Board Review MCQs (2026 Edition) - Part 3

In a cadaver ligament sectioning study, the posterior capsular ligament was considered the most important structure for anterior-posterior stability of the sternoclavicular joint. The anterior capsular ligament also helps prevent anterior displacement but not to the same degree as the posterior ligament. The interclavicular ligament provides little support for anteroposterior translation.
REFERENCES: Spencer EE, Kuhn JE, Huston LJ, et al: Ligamentous restraints to anterior and posterior translation of the sternoclavicular joint. J Shoulder Elbow Surg 2002;11:43-47.
Rockwood CA Jr, Matsen FA III, Jobe CM: Gross Anatomy of the Shoulder. Philadelphia, PA, WB Saunders, 1998.

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1. Reference(s)
2. Fronek J, Warren RF, Bowen M: Posterior subluxation of the glenohumeral joint. J Bone Joint Surg 1989;71A:205-216.
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This patient presents with an acute neuroarthropathy. The acute painless swelling, associated with warmth and absence of radiographic findings, is typical of the acute phase of a C harcot process. A short leg cast or a boot to immobilize the foot is ideal, and no weight bearing should be permitted until the acute phase of this neuroarthropathy has subsided.

- Subtalar arthritis_

Ankylosing spinal disorders, including ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis, are conditions that make the spine rigid and at risk for 3-column unstable fractures. Spinal fractures in these patients pose high risk for complications and death and patients should be counseled and observed closely. Mortality strongly correlates with older age and increased number of comorbidities.
These spine fractures often are not seen at the time of initial evaluation, and a delay in diagnosis can occur in up to 19% of cases. This is particularly common in the setting of non- or minimally displaced fractures following minor injuries. A delayed diagnosis can lead to displacement of a previously nondisplaced fracture that can incur a high neurologic injury risk. Advanced imaging with a CT scan or MRI should be obtained for patients with ankylosing spinal disorders even when minor injuries occur. Although bracing and observation can be used, posterior multilevel spinal instrumentation is typically required to obtain adequate spinal stabilization.
The radiographs show an osteopenic ankylosed thoracic spine; the anteroposterior radiograph clearly shows fusion of the sacroiliac joints. Recognition of these radiographic findings is important when evaluating patients after an injury.
# RECOMMENDED READINGS
[Caron T, Bransford R, Nguyen Q, Agel J, Chapman J, Bellabarba C. Spine fractures in patients with ankylosing spinal disorders. Spine (Phila Pa 1976). 2010 May 15;35(11):E458-64. doi: 10.1097/BRS.0b013e3181cc764f. PubMed PMID: 20421858. ](http://www.ncbi.nlm.nih.gov/pubmed/20421858)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/20421858)
[Hendrix RW, Melany M, Miller F, Rogers LF. Fracture of the spine in patients with ankylosis due to diffuse skeletal hyperostosis: clinical and imaging findings. AJR Am J Roentgenol. 1994 Apr;162(4):899-904. PubMed PMID: 8141015. ](http://www.ncbi.nlm.nih.gov/pubmed/8141015)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/8141015)

Resection posterior to the midpoint of the radiocapitellar joint can result in damage to the lateral collateral ligament and subsequent development of posterolateral rotator instability.

A clinical series of 122 bunions was evaluated for demographic, etiologic, and radiographic findings associated with moderate to severe hallux valgus deformity. The following findings were reported:
83% of patients had a positive family history of bunions
84% of patients had bilateral bunion deformities
71% of patients had curved or oval-shaped metatarsophalangeal joints
71% of patients had a longer 1st metatarsal compared to the 2nd metatarsal by an average of 2.4 mm
11% of bunions were associated with an Achilles tendon contracture

Flow cytometry and cytogenetic analysis are frequently crucial to make an accurate diagnosis of leukemia and lymphoma. These techniques are best performed on fresh, unfixed tissue. Optimal technique includes moistening the tissue to prevent desiccation and immediately sending the specimen for pathologic analysis. Communication with the pathologist regarding the possibility of
a leukemia or lymphoma is prudent to facilitate prompt processing. It is advisable to have a hematology technician in the operating room to handle tissue. Sampling the periphery of tumors with cystic components is often necessary to obtain cellular tissue, but this necessity is not specific to leukemia and lymphoma cases. Formalin is the standard tissue preservation solution for most biopsies. RNA stabilization solution is usually used for research rather than clinical purposes.
RECOMMENDED READINGS
101. [Traina F, Errani C, Toscano A, Pungetti C, Fabbri D, Mazzotti A, Donati D, Faldini C. Current concepts in the biopsy of musculoskeletal tumors: AAOS exhibit selection. J Bone Joint Surg Am. 2015 Jan 21;97(2):e7. doi: 10.2106/JBJS.N.00661. Review. PubMed PMID: 25609446. ](http://www.ncbi.nlm.nih.gov/pubmed/25609446)[View Abstract at](http://www.ncbi.nlm.nih.gov/pubmed/25609446)[ ](http://www.ncbi.nlm.nih.gov/pubmed/25609446)[PubMed](http://www.ncbi.nlm.nih.gov/pubmed/25609446)
102. Virgo PF, Gibbs GJ. Flow cytometry in clinical pathology. Ann Clin Biochem. 2012 Jan;49(Pt 1):17-
[28/. doi: 10.1258/acb.2011.011128. Epub 2011 Oct 25. Review. PubMed PMID: 22028426. ](http://www.ncbi.nlm.nih.gov/pubmed/22028426)[View](http://www.ncbi.nlm.nih.gov/pubmed/22028426)[ ](http://www.ncbi.nlm.nih.gov/pubmed/22028426)[Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/22028426)
103. Huang Q, Reddi D, Chu P, Snyder DS, Weisenburger DD. Clinical and pathologic analysis of extramedullary tumors after hematopoietic stem cell transplantation. Hum Pathol. 2014 Dec;45(12):2404-10. doi: 10.1016/j.humpath.2014.07.022. Epub 2014 Aug 23. PubMed PMID:
[25294373/. ](http://www.ncbi.nlm.nih.gov/pubmed/25294373)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/25294373)

rTSA originally was used to address rotator cuff arthropathy. Current indications have expanded to include massive rotator cuff tears without arthritis, failed shoulder arthroplasty, 3- and 4-part proximal humerus fractures, and glenohumeral arthrosis associated with severe/uncorrectable glenoid retroversion. rTSA volume has increased, leading to identification of problems specific to the procedure. Some of the common complications include neurologic injury, periprosthetic fracture, hematoma, infection, scapular notching, prosthetic joint instability, baseplate failure, and acromial fracture. A meta-analysis performed by Bohsali and associates involving rTSA
demonstrated these complications in decreasing order of frequency: scapular notching, hematoma formation, glenoid dissociation such as baseplate failure or aseptic loosening, glenohumeral dislocation, acromial and/or scapular spine fracture, infection, loosening or dissociation of the humeral component, and nerve injury.
RECOMMENDED READINGS
6. [Cheung E, Willis M, Walker M, Clark R, Frankle MA. Complications in reverse total shoulder arthroplasty. J Am Acad Orthop Surg. 2011 Jul;19(7):439-49. Review. ](http://www.ncbi.nlm.nih.gov/pubmed/21724923)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/21724923)
7. [Bohsali KI, Wirth MA, Rockwood CA Jr. Complications of total shoulder arthroplasty. J Bone Joint Surg Am. 2006 Oct;88(10):2279-92. Review. PubMed PMID: 17015609. ](http://www.ncbi.nlm.nih.gov/pubmed/17015609)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/17015609)

This clinical scenario describes a patient with an isolated injury affecting the infraspinatus muscle. The anatomic location of such a lesion would be at the spinoglenoid notch, at which the suprascapular nerve may be compressed distal to its innervation of the supraspinatus but proximal to the infraspinatus innervation. A calcified transverse scapular ligament would also affect the suprascapular nerve but is proximal to the innervation of both muscles. Quadrilateral space syndrome would affect innervation of the deltoid (and teres minor). Parsonage-Turner syndrome is a more diffuse, and often severely painful, brachial plexus neuropathy.

- Dexamethasone

Many patients with mild dominant OI (the most common type) appear “normal,” and a diagnosis cannot be made without a careful personal history, family history, and observance of blue sclera. More than 3 fractures during childhood places someone outside of the mean and should merit further investigation. There is no sign of rickets on this radiograph (physeal widening/cupping). Similarly, the history and examination finding of blue sclera in the patient and his mother should raise concern for OI. Many parents of children with OI have inappropriately been accused of abuse despite obvious examination, radiograph, and family history findings that suggest OI. Low-energy mechanisms that create displaced fractures are a hallmark of OI and do not in isolation raise suspicion for nonaccidental trauma.
Based on the history and examination, mild-form OI caused by a defect in the type I collagen gene is most likely. Defects in type II collagen genes affect articular cartilage and cause epiphyseal dysplasia. Defects in the LEPRE cause severe-form OI involving clinically bowed limbs, marked short stature, and white sclera. There is no sign on radiographs of rickets, so severe vitamin D deficiency is not present. The history, examination, and radiographs all point toward OI/osteoporosis rather than nonaccidental trauma.
Peri-implant fractures occur because of a difference in elasticity between the bone with implants and the bone adjacent to it without implants. This is particularly important in the setting of osteoporotic bone in which the difference in elasticity and rigidity will be much more pronounced than in normal bone. Load-sharing implants are preferred when possible. The original fracture occurred proximal to the current fracture in the middle of the plated bone and looks healed with no sign of infection.
This fracture is in unacceptable alignment with subluxation of the radiocapitellar joint. The plates are bent, so closed reduction will not solve the alignment problem. In early childhood, load-sharing implants (flexible rods or wires) should be used to solve the elasticity mismatch that contributed to the current fracture.
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Figure 51a
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Figure 51b
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Figure 51c
## CLINICAL SITUATION FOR QUESTIONS 51 THROUGH 54
Figures 51a through 51c are the radiographs of an 8-year-old boy with a shoulder deformity and limited cervical range of motion. He has no significant medical problems and plays baseball, pitching with his right arm. His active shoulder abduction is 180 degrees on the left and 150 degrees on the right.

One hundred twenty patients with ankle fractures were evaluated. Symptomatic superficial peroneal nerve injury was identified in
21% of patients who underwent open reduction internal fixation and 9% of nonoperatively treated patients. AOFAS scores were decreased in patients with symptomatic superficial peroneal nerve injury. No injuries to the superficial peroneal nerve occurred in patients who underwent surgery involving a posterolateral approach to the fibula.

Intravenous antibiotics are critical to prevent infection in open fractures. Delay in administration of intravenous antibiotics has been linked with increased risk of infection.
Open tibia fractures are associated with high rates of infection. Historically,
early debridement (within 6-8 hours) and early flap coverage (typically defined as less than 72 hours) were thought to minimize the risk of infection. Recent evidence has challenged these findings, with multiple studies demonstrating no significant link between the timing of debridement and rates of infection.
Multiple studies from the Lower Extremity Assessment Project (LEAP) found no significant difference in infection or complication with flap coverage more than 72 hours after injury.
Bhattacharyya et al retrospectively evaluated patients with type IIIB tibial fractures treated with extended use of negative pressure wound therapy. The authors found increased rates of infection beyond 7 days despite the use of negative pressure wound therapy.
Lack et al evaluated the timing of antibiotic administration on infection rates for type III tibial fractures. The authors found increased rates of infection with administration of antibiotics beyond 66 minutes. The authors discuss the possibility of pre-hospital intervention as many severely injured patients have delayed arrival at treatment centers.
Pollak et al prospectively analyzed rates of complication with flap coverage as part of the LEAP study. The authors found no increase in complications with flap coverage beyond 72 hours. The only significant risk for complication was the use of rotational flaps in comminuted or segmental (AO/OTA type C) tibial fractures.
Incorrect answers:
Answer 1: Lower rates of complication, including infection, were seen with free flaps in AO/OTA type C fractures in the study by Pollak et al.
Answer 2: Timing of flap coverage is controversial. Early studies demonstrated increased infection with delay beyond 72 hours, however recent studies using more rigorous statistical analysis do not support these findings.
Answer 3: No study has demonstrated lower infection rates with the use of plating versus nailing in open tibial fractures.
Answer 5: The timing of debridement with open fractures has been shown not to effect the rate of infection in multiple recent studies.

Varus posteromedial rotatory instability is a complex injury pattern that starts with varus stress resulting in a fracture of the anteromedial coronoid. The anterior MCL attaches to the sublime tubercle, which is part of the anteromedial coronoid facet. The posterior MCL attaches to the posterior medial aspect of the ulna. The radial collateral and lateral ulnar collateral attach to the ulna at the crista supinatoris. The bony landmark is the sublime tubercle; as noted above, the crista supinatoris is lateral on the ulna. The radial notch is also lateral and is the articulation between the proximal ulna and proximal radius. The anteromedial coronoid facet is part of the coronoid, which extends more lateral and anterior than the anteromedial facet. The anteromedial facet represents the critical weight-bearing portion of the ulnohumeral joint. Damage to this structure causes posteromedial subluxation that often results in severe progressive arthritis. The coronoid is the larger structure of which the anteromedial coronoid facet is a portion. The posteromedial coronoid facet does not appear to be critical in weight bearing. The radial notch is not associated with increased stress with weight bearing. The treatment of displaced fractures of this structure is open reduction and internal fixation utilizing buttress plating. Closed treatment is acceptable only for nondisplaced fractures with appropriate radiographic follow-up. Suture fixation is not advocated because of inadequate strength.
RECOMMENDED READINGS
1. Pollock JW, Brownhill J, Ferreira L, McDonald CP, Johnson J, King G. The effect of anteromedial facet fractures of the coronoid and lateral collateral ligament injury on elbow stability and kinematics. J Bone Joint Surg Am. 2009 Jun;91(6):1448-58. doi: 10.2106/JBJS.H.00222.
2. Sanchez-Sotelo J, O'Driscoll SW, Morrey BF. Anteromedial fracture of the coronoid process of the ulna. J Shoulder Elbow Surg. 2006 Sep-Oct;15(5):e5-8. Epub 2006 Jul 26. Erratum in: J Shoulder Elbow Surg. 2007 Jan-Feb;16(1):127. PubMed PMID: 16979044.

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#### DISCUSSION: Cervical spinal stenosis is a contraindication to participation in collision and contact sports. Previously, the risks of permanent quadriparesis from cervical spinal stenosis were thought to be unclear and athletes with cervical spinal stenosis were often allowed to play contact sports. In 1996, Torg and associates reported that developmental narrowing of the cervical canal in a stable patient does not appear to predispose an individual to permanent catastrophic neurologic injury and therefore should not preclude an athlete from participation in contact sports. However, the current understanding is that the actual risks of permanent neurologic injury from cervical stenosis are significant. The Torg ratio was previously used for diagnosis but is more recently thought to be of low predictive value as reported by Cantu. Current methods for diagnosis of cervical spinal stenosis rely on MRI and CT. Current diagnosis is based on comparisons of measurements with normal values. A cervical canal of less than 13 mm is considered stenotic whereas a diameter of less than 10 mm is considered absolute stenosis as reported by Crowl and Kong. This patient has symptomatic stenosis and should not be cleared for contact sports. A neck roll will not prevent neurologic injury in the presence of cervical spinal stenosis. Electrodiagnostic studies are not likely to add any additional significant findings with central canal stenosis. Cervical traction is not of value in the long-term. Epidural steroid injections or a methylprednisolone dose pack are not of value in this situation.
####
#### REFERENCES: Torg JS, Naranja RJ Jr, Pavlov H, et al: The relationship of developmental narrowing of the cervical spinal canal to reversible and irreversible injury of the cervical spinal cord in football players. J Bone Joint Surg Am 1996;78:1308-1314.
#### Cantu RC: The cervical spinal stenosis controversy. Clin Sports Med 1998;17:121-126. Crowl AC, Kong JF: Cervical Spine, in Johnson DL, Mair SD (eds): Clinical Sports Medicine. Philadelphia, PA, Mosby Elsevier, 2006, pp 143-149.
####

Restoration of the anatomy of the radial bow directly correlates with the range of motion postoperatively (pronation-supination).
The referenced study by Schemitsch et al found that restoration of the normal radial bow was related to the functional outcome. A good functional result
(more than 80 percent of normal rotation of the forearm) was associated with restoration of the normal amount and location of the radial bow. Similarly, the recovery of grip strength was associated with restoration of the location of the radial bow toward normal.

Tinel sign is seen with postganglionic lesions.

Nausea, hypotension, respiratory depression, and peroneal nerve palsy are associated with epidural analgesia. Be aware of an epidural bleed secondary to anticoagulation efforts for deep venous thrombosis prophylaxis

Suprascapular nerve palsy is a fairly uncommon yet well-known cause of shoulder pain and weakness. A variety of causes have been described, including compression by a ganglion cyst, an anomalous or thickened superior transverse scapular ligament, a humeral and scapular fracture, and traction or kinking of the nerve in the suprascapular notch.
In this patient, the injury is most likely caused by traction or compression of the nerve in the suprascapular notch as the result of positioning during abdominal surgery; therefore, the studies of choice are electromyography and nerve conduction velocity studies. While MRI of the cervical spine may be of some value in ruling out a radiculopathy, the clinical history does not support such a cause for this condition.
REFERENCES: Rengachary SS, Neff JP, Singer PA, Brackett CE: Suprascapular entrapment neuropathy: A clinical, anatomical, and comparative study. Part 1: Clinical study. Neurosurgery 1979;5:441-446.
Rengachary SS, Burr D, Lucas S, Hassanein KM, Mohn MP, Matzke H: Suprascapular entrapment neuropathy: A clinical, anatomical and comparative study. Part 2: Anatomical study. Neurosurgery 1979;5:447-451.
Bigliani LU, Dalsey RM, McCann PD, April EW: An anatomical study of the suprascapular nerve. Arthoscopy 1990;6:301-305.

The established criteria for interpreting a significant change are 50% decrease in signal amplitude, 10% latency increase, and/or a complete loss of potential. Intraoperative spinal cord monitoring during spinal surgery generally consists of a combination of monitoring modalities.Somatosensory-evoked potentials in combination with intraoperative electromyography can provide adequate coverage of sensory and motor components of spinal cord and nerve root function. Significant changes in evoked potential waveform characteristics can reflect dysfunction of the ascending somatosensory system.

Although the woman may wish to wear shoes of varying height, there is sufficient plantarflexion occurring through the transverse tarsal joint to permit the wearing of high-heel shoes. Any plantarflexion of the fusion will cause arthritis of the transverse tarsal joint, particularly the talonavicular joint. Dorsiflexion of an ankle arthrodesis is associated with a calcaneus position and heel pain. The ankle should be fused in a similar position for both male and female patients.

Studies by Livesley, Kjaer-Petersen, and others have shown that patients with fractures with more than a 1-mm step-off after reduction were more likely to develop arthritis at the thumb carpometacarpal joint. Although some studies have not shown functional outcome correlating with the presence of arthritis, Oosterbos and De Boer found that all their patients with fair and poor overall results had nonanatomic reductions. Although a cadaveric study by C ullen has shown that a 2-mm step-off may be acceptable, this contrasts with the clinical evidence currently available.

Active osteoclasts resorb the mineral and organiCmatrix of bone and attach to the exposed bone matrix. When osteoclasts are studied with an electron microscope, there are two prominent findings â a ruffled border and a clear zone. In the clear zone, the osteoclast seals off the area of bone to be resorbed by attaching to the bone surface. The osteoclast attaches to the bone surface through a receptor-mediated process with the assistance of proteins called integrins. The ruffled border is an area found in the infoldings of the cell membrane. At the area of the ruffled border, the osteoclasts lower the pH with hydrogen ions through the carboniCanhydrase system. This lowered pH increases the solubility of the apatite crystals and the mineral can be removed. The organiCcomponents of the bone are then hydrolyzed through acidiCproteolytiCdigestion.

Several neurological manifestations have been attributed to Al intoxication in humans, including memory loss, jerking, ataxia, and neurofibrillary degeneration. The development of some neuropathological conditions, including amyotrophiClateral sclerosis, Parkinsonian, dementia, dialysis encephalopathy, and senile plaques of Alzheimerâs disease, may be related to the accumulation of Al in the brain

Subchondral drilling allows the blood supply to form clot-containing stem cells from which fibrocartilage forms. It is not indicated in patients with systemiCdisease like rheumatoid arthritis. It is ineffective for varus or valgus alignment or subchondral sclerosis

Absence of the rotator cuff results in superior migration of the humeral head because of unopposed deltoid function. This proximal migration results in eccentric loading of glenoid components with early loosening. Hemiarthroplasty yields good pain relief with limited goals of active elevation of 90 degrees. The coracoacromial arch should be preserved. Achieving satisfactory subscapularis tension is preferred to the use of an oversized humeral component.
REFERENCES: Zeman CA, Arcand MA, Cantrell JS, Skedros JG, Burkhead WZ Jr: The rotator cuff-deficient arthritic shoulder: Diagnosis and surgical management. J Am Acad Orthop Surg 1998;6:337-348.
Arntz CT, Jackins S, Matsen FA III: Prosthetic replacement of the shoulder for the treatment of defects in the rotator cuff and the surface of the glenohumeral joint. J Bone Joint Surg Am 1993;75:485-491.
Williams GR Jr, Rockwood CA Jr: Hemiarthroplasty in rotator cuff-deficient shoulders. J Shoulder Elbow Surg 1996;5:362-367.
Zuckerman JD, Scott AJ, Gallagher MA: Hemiarthroplasty for cuff tear arthropathy. J Shoulder Elbow Surg 2000;9:169-172.

Figures A and B show a significantly comminuted, segmental tibial fracture. In this scenario, the fracture is appropriately classified as a Grade III because there is a highly comminuted, segmental fracture which is always associated with significant periosteal stripping. The patient's leg was able to be closed primarily, which means that it should be classified as a IIIA.
Gustilo et al reviews 18 years of open fracture treatment and outcomes. They reported that débridement and copious irrigation, with primary closure for type I and II fractures and secondary closure for type III fractures resulted in a 5% infection rate (9% for type III fractures). Initial wound cultures were positive in 70.3% despite an infection rate of that patient group of only 2.5%.
Incorrect Answers:
Answer 1: Gustilo Type I wounds have a clean skin lesion that are < 1 cm, and a simple fracture with minimal comminution.
Answer 2: Gustilo Type II wounds have a skin lesion > 1 cm, no extensive soft tissue damage, minimal crushing, and moderate comminution and contamination.
Answer 4: Gustilo Type IIIB are defined as wounds that require a flap for salvage.
Answer 5: Gustilo Type IIIC have an exposed fracture with arterial damage that requires repair.

#### DISCUSSION: The well-conditioned heart of an athlete leads to increased ventricular wall thickness which in turn increases the amount of blood ejected from the heart per given stroke (stroke volume). The increased parasympathetic (vagal) tone also leads to a lower (decreased) resting heart rate. Cardiac output is equal to stroke volume x heart rate and is increased during exercise in a well-conditioned athlete.
#### REFERENCES: Basilico FC: Cardiovascular disease in athletes. Am J Sports Med 1999;27:108-121. Huston TP, Puffer JC, Rodney WM: The athletic heart syndrome. N Engl J Med 1985;313:24-32.
#### An 18-year-old boxer sustained a blow to his right eye in a boxing match. Examination on the sideline reveals hyphema, reduced visual acuity and color vision, and a visual field cut. What is the next step in management?
1. #### Eye patch and ophthalmology evaluation in 2 days
2. #### Fluorescein eye stain
3. #### Emergent CT
4. #### High-dose systemic steroids
5. #### Observation PREFERRED RESPONSE: 3
#### DISCUSSION: With the examination demonstrating reduced visual acuity and visual field changes,
#### 2010 Sports Medicine Examination Answer Book • 81
####

##### DISCUSSION: The radiographs and MRI scan show a displaced tibial eminence fracture. Meyer and McKeever classified these injuries, with type 1 being a nondisplaced tibial eminence fracture; type 2 being a displaced tibial eminence fracture with a posterior hinge, and type 3 being a displaced tibial eminence fracture. Tibial eminence fractures in children are equivalent to anterior cruciate ligament tears in adults. Treatment should be anatomic reduction, which often requires an arthroscopic or open procedure, followed by fixation.
##### REFERENCES: Green NE, Swiontkowski MF: Skeletal Trauma in Children, ed 3. Philadelphia, PA, WB Saunders, 2003, pp xvi, 452-455, 638.
##### Zionts LE: Fractures around the knee in children. J Am Acad Orthop Surg 2002;10:345-355.
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##### 2010 Pediatric Orthopaedic Examination Answer Book • 79
#####

##### Figure 96

Patients with cerebral palsy do not have an increased risk of congenital vertical talus, but they may develop an acquired neuromuscular vertical talus.
Patients with myelomeningocele have approximately a 5% to 10% risk of vertical talus, far above that of the general population.
Arthrogryposis is associated with an increased risk of vertical talus.
Nail patella syndrome is associated with an increased risk of vertical talus. Sacral agenesis is associated with an increased risk of vertical talus.

- Intraoperative neurological injury

Intercondylar fractures have a significant risk of loss of motion because of the magnitude of injury, intra-articular extension, and older age of patient.
Salter I physeal fractures typically occur in young children. They usually pose no difficulty with regaining motion after 4 to
6 weeks of immobilization.
Supracondylar fractures usually are followed by regaining motion after healing despite immobilization of up to 6 weeks or more.
Patients with this fracture usually regain their motion after healing. Because this is a nonarticular fracture, loss of motion is not a high risk.

C omputer tomography scan of the cervical spine will not be of any use as it will neither show the pseudomeningoceles nor provide any information on brachial plexus. C T scan may be needed in case of a suspected neck injury but does not form part of a
brachial plexus work up.

### DISCUSSION: Slight external rotation of the tibial component medializes the tibial tubercle and helps reduce the tendency for lateral patellar maltracking. Mobile bearings have not been shown to improve patellar tracking.
###
### Internal rotation of the tibial or femoral component will accentuate patellar maltracking. AP positioning of the tibial tray will affect the force across the patella, but it is not likely to affect patellar tracking.
###
### REFERENCES: Pelicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 323-337. Pagnano MW, Trousdale RT, Stuart MJ, et al: Rotating platform knees did not improve patellar tracking: A prospective randomized study of 240 primary total knee arthroplasties. Clin Orthop Relat Res 2004:428:221-227.
###
### Figure 77a Figure 77b
###

A Syme amputation is effectively a tibiotalar disarticulation, which provides an end-bearing stump that could potentially allow ambulation without a prosthesis over short distances. It works better for tumor and trauma, but the heel pad must be viable. The two most common problems are 1) skin sloughing from compromised vascular supply and 2) migration of the heel pad due to instability. A hypermobile heel pad can cause difficulty with prosthesis wear and damage to the soft tissues which can eventually lead to failure. Both malleoli are usually removed in the procedure, except in children or during the first stage procedure of a diabetic or infection case. The tibialis anterior is usually tenodesed to the anterior heel pad along with the EDL tendon to avoid posterior migration of the heel pad.

Anterior and posterior fusion will correct the translation, instability, and ensure a solid fusion.
Exercises will not correct the subluxation, which is the cause of the pain. A thoracolumbar orthosis is not corrective or well tolerated.
There is no need for halo traction.
Posterior fusion alone is not enough to control this focal instability if the patient is well enough to tolerate a more involved procedure.

This patient’s clinical presentation is consistent with internal impingement accompanied by glenohumeral internal rotation deficit (GIRD). Although throwers may have increased external rotation, their overall arc of motion should be the same as on the nonthrowing side. In comparison, patients with GIRD experience a marked decrease in arc of motion, particularly in internal rotation.
Internal impingement represents a spectrum of findings that can include superior and posterior labral tears, undersurface (articular-sided) tearing of the posterior supraspinatus, posterior glenoid wear, and scar formation of the posterior capsule. Myers and associates demonstrated internal impingement is associated with GIRD, although the latter by itself may be asymptomatic and perhaps a sports-specific adaptation. However, posterior capsular tightness can lead to posterosuperior translation of the humerus during throwing, leading to these injuries. Internal impingement is common among overhead throwing athletes and occurs during the late cocking and early acceleration phases of throwing. Humeral migration during the abducted/externally rotated throwing position results in abutment of the greater tuberosity against the posterosuperior glenoid labrum, which impinges the rotator cuff (Paley and associates).
Pain is often posterior, but symptoms can be vague. Patients may have examination findings consistent with rotator cuff weakness and superior labrum anterior to posterior (SLAP)/biceps involvement. Radiograph findings can be negative, although a Bennett lesion involving hypertrophy and mineralization of the posterior capsular injury may be seen (Wright and Paletta). A CT scan may show glenoid retroversion (Crockett and associates), while MR imaging should be reviewed for a possible partial articular-sided rotator cuff tear, SLAP tear, or increased signal in the posterosuperior labrum or greater tuberosity.
Treatment of this condition should be the focus on therapy, and most cases can be treated nonsurgically. Stretching aimed at the posterior capsule (ie, sleeper stretch) has been reported as effective (Tyler and associates, Litner and associates). Burkhart and associates also demonstrated posterior capsular stretching can help prevent throwing injuries. Because cuff pathology may be present, physical therapy also should include rotator strengthening, scapular stabilization, and addressing of issues related to throwing mechanics (Drakos and associates). Kibler and associates published a comprehensive rehabilitation guideline. Surgical intervention is reserved for those who fail 6 months of nonsurgical treatment and is directed by intra-articular pathology (debridement vs repair of the rotator cuff and labrum) (Braun and associates).
RECOMMENDED READINGS
13. [Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology Part I: pathoanatomy and biomechanics. Arthroscopy. 2003 Apr;19(4):404-20. Review. PubMed PMID: 12671624. ](http://www.ncbi.nlm.nih.gov/pubmed/12671624)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/12671624)
14. [Braun S, Kokmeyer D, Millett PJ. Shoulder injuries in the throwing athlete. J Bone Joint Surg Am. 2009 Apr;91(4):966-78. doi: 10.2106/JBJS.H.01341. Review. ](http://www.ncbi.nlm.nih.gov/pubmed/19339585)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/19339585)
15. [Crockett HC, Gross LB, Wilk KE, Schwartz ML, Reed J, O'Mara J, Reilly MT, Dugas JR, Meister K, Lyman S, Andrews JR. Osseous adaptation and range of motion at the glenohumeral joint in professional baseball pitchers. Am J Sports Med. 2002 Jan-Feb;30(1):20-6. ](http://www.ncbi.nlm.nih.gov/pubmed/11798991)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/11798991)
16. [Drakos MC, Rudzki JR, Allen AA, Potter HG, Altchek DW. Internal impingement of the shoulder in the overhead athlete. J Bone Joint Surg Am. 2009 Nov;91(11):2719-28. doi: 10.2106/JBJS.I.00409. Review. PubMed PMID: 19884449.](http://www.ncbi.nlm.nih.gov/pubmed/19884449)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/19884449)
17. [Kibler WB, McMullen J, Uhl T. Shoulder rehabilitation strategies, guidelines, and practice. Orthop Clin North Am. 2001 Jul;32(3):527-38. Review. ](http://www.ncbi.nlm.nih.gov/pubmed/11888148)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/11888148)
18. [Lintner D, Mayol M, Uzodinma O, Jones R, Labossiere D. Glenohumeral internal rotation deficits in professional pitchers enrolled in an internal rotation stretching program. Am J Sports Med. 2007 Apr;35(4):617-21. Epub 2007 Feb 9. PubMed PMID: 17293473. ](http://www.ncbi.nlm.nih.gov/pubmed/17293473)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/17293473)
19. [Myers JB, Laudner KG, Pasquale MR, Bradley JP, Lephart SM. Glenohumeral range of motion deficits and posterior shoulder tightness in throwers with pathologic internal impingement. Am J Sports Med. 2006 Mar;34(3):385-91. Epub 2005 Nov 22. PubMed PMID: 16303877. ](http://www.ncbi.nlm.nih.gov/pubmed/16303877)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/16303877)
20. [Paley KJ, Jobe FW, Pink MM, Kvitne RS, ElAttrache NS. Arthroscopic findings in the overhand throwing athlete: evidence for posterior internal impingement of the rotator cuff. Arthroscopy. 2000 Jan-Feb;16(1):35-40. PubMed PMID: 10627343. ](http://www.ncbi.nlm.nih.gov/pubmed/10627343)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/10627343)
21. [Tyler TF, Nicholas SJ, Lee SJ, Mullaney M, McHugh MP. Correction of posterior shoulder tightness is associated with symptom resolution in patients with internal impingement. Am J Sports Med. 2010 Jan;38(1):114-9. doi: 10.1177/0363546509346050. Epub 2009 Dec 4. ](http://www.ncbi.nlm.nih.gov/pubmed/19966099)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/19966099)
22. [Wright RW, Paletta GA Jr. Prevalence of the Bennett lesion of the shoulder in major league pitchers. Am J Sports Med. 2004 Jan-Feb;32(1):121-4. PubMed PMID: 14754734. ](http://www.ncbi.nlm.nih.gov/pubmed/14754734)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/14754734)

- Osteoid osteoma_

Posttraumatic physeal arrest occurs most commonly in the distal medial tibia. Using MRI, Echlund and associates confirmed this finding. Arrest of the distal radius and proximal humerus are rare after trauma. Traumatic injuries of the distal femoral and distal ulnar physis have a high incidence of growth arrest as well.
REFERENCES: Ecklund K, Jaramillo D: Patterns of premature physeal arrest: MR imaging of 111 children. AJR Am J Roentgenol 2002; 178:967-972.
_YAtotoartanadQpyiQter GN: Physeal bridge resection. J Am Acad Orthop Surg 2005; 13:4_


Figure 64a Figure 64b

The radiograph reveals end-stage degenerative changes of the first MTP joint with a dorsal loose body. MTP arthritis and decreased joint dorsiflexion is referred to as hallux rigidus. A chevron bunionectomy is used to correct hallux valgus deformity without arthritis. The cheilectomy is used in lesser degrees of joint destruction. Resection of the proximal phalanx results in a floppy toe and is generally not recommended.
# RECOMMENDED READINGS
McNeil DS, Baumhauer JF, Glazebrook MA. Evidence-based analysis of the efficacy for operative treatment of hallux rigidus. Foot Ankle Int. 2013 Jan;34(1):15-32. doi: 10.1177/1071100712460220. Review. PubMed PMID: 23386758.
[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/23386758)
Deland JT, Williams BR. Surgical management of hallux rigidus. J Am Acad Orthop Surg. 2012 Jun;20(6):347-58. doi: 10.5435/JAAOS-20-06-347. Review. PubMed PMID: 22661564.
[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/%2022661564)
# CLINICAL SITUATION FOR QUESTIONS 55 THROUGH 58
Figures 55a and 55b are the anteroposterior and lateral radiographs of a 57-year-old man who fell off of a ladder 10 days ago and landed on his left foot. He is now unable to weight bear on the left. He has no history of trauma to this foot, and his medical history is unremarkable. Upon examination his left foot is swollen and tender. Pulses and sensation are intact.


A B

Generally, it is best to increase training time and intensity by 150 nm) can stimulate phagocytosis in specialized cells such as macrophages. Once internalized, metal particles can induce cytotoxicity, chromosomal damage, and oxidative stress. The toxicity of particles is modified by passivation and particle size. These factors both influence the dissolution of metal from the surface, which may account for biological activity. Evidence of cell damage, such as irregular cell membranes and enlarged mitochondria, may be induced by the physical properties of the particles

- is performed with the elbow in flexion to minimize the function of the brachialis._

This patient most likely has an acute attack of gout. The prior episodes of foot pain and the sudden onset lasting 5 days for each bout is characteristic. The ankle is not a common location for gout (the most frequent site is the hallux metatarsophalangeal joint). The treatment should consist of injection of a corticosteroid into the joint and administration of appropriate oral anti-inflammatory medication.

The patient has a pectoralis major rupture, an injury that occurs most commonly during weight lifting. Grade III injuries represent complete tears of either the musculotendinous junction or an avulsion of the tendon from the humerus, the most common injury site. Examination will most likely reveal ecchymoses and swelling in the proximal arm and axilla, and strength testing will show weakness with internal rotation and in adduction and forward flexion. Axillary webbing, caused by a more defined inferior margin of the anterior deltoid as the result of rupture of the pectoralis, can be seen as the swelling diminishes. Surgical repair is the treatment of choice for complete ruptures. Nonsurgical treatment is associated with significant losses in adduction, flexion, internal rotation, strength, and peak torque. The pectoralis major originates from the proximal clavicle and the border of the sternum, including ribs two through six. The pectoralis major inserts (rather than originates) on the humerus. The coracoid process is the insertion site for the pectoralis minor, as well as the origin for the conjoined tendon. The pectoralis major has no attachment or origin from the scapula. The anterior deltoid originates from the lateral one third of the clavicle and the anterior acromion.
REFERENCES: Miller MD, Johnson DL, Fu FH, Thaete FL, Blanc RO: Rupture of the pectoralis major muscle in a collegiate football player: Use of magnetic resonance imaging in early diagnosis. Am J Sports Med 1993;21:475-477.
Wolfe SW, Wickiewicz TL, Cavanaugh JT: Ruptures of the pectoralis major muscle: An anatomic and clinical analysis. Am J Sports Med 1992;20:587-593.

■
The patient has degenerative disk disease with diskogenic back pain. Several studies in both humans and animals have implicated TNF-α, IL-1, and MMP in extracellular matrix degeneration and disk degradation. TGF-β, BMP-2, latent membrane protein 1, and growth and development factor-5 are all postulated to play anabolic roles in the intervertebral disk. Biglycan is a small leucine-rich proteoglycan that regulates extracellular matrix assembly within the disk. Noggin and gremlin are biochemical factors not involved in disk degradation.

Lateral plating of the distal fibula has an increased risk of intra-articular screw penetration with the trajectory of the screws distally; bicortical screws will be intra-articular in nature, whereas posterior plating screws will exit anteriorly.
Figure A shows an antiglide (posterior) plating of the distal fibula, while Figure B shows a lateral neutralization plating of the distal fibula. Both methods are acceptable, but posterior antiglide plating is associated with increased construct stiffness and strength, decreased hardware prominence, decreased rates of ankle joint screw penetration, and improved biomechanical findings in osteoporotic bone. However, posterior plating is associated with an increased rate of peroneal tendonitis and irritation. Illustration A shows a lateral radiograph of a posterior fibular plate.
The referenced article by Ostrum et al is a case series of 32 patients who had antiglide plating; he reported a 100% union rate, 95% patient satisfaction rate, and only 4/32 reported peroneal tendinitis, with all resolving by 2
months.
The other referenced article by Schaffer et al reported that the posterolateral antiglide plate demonstrated improved biomechanical stability as compared to the lateral plating, with increased construct stiffness and load to failure.

Flexor tendon nutrition in the uninjured state is derived via the vincula, which contain blood vessels for nutrition. Injured tendons obtain nutrition via diffusion of synovial fluid. The pulley system does not contribute to flexor tendon nutrition.

4-5 intermetarsal angle in normal feet averages 6.2 degrees. Different authors believe an abnormally wide 4-5 intermetatarsal angle to be anything greater than 8°-9°.

The ultrasound shows a homogeneous anechoic mass consistent with a ganglion cyst. As a benign lesion, no further workup or biopsy is required prior to a marginal surgical excision other than age-appropriate laboratory studies. An MRI study with contrast would provide no diagnostic benefit.

**
Gout is an inflammatory arthritis caused by the presence of monosodium urate crystals in the joint. It is characterized acutely by a painful joint that remits after 1 to 2 weeks and recurs periodically. The diagnosis of gout can be made by confirming the presence of monosodium urate crystals in the joint fluid
aspirated from the inflamed joint. Patients with gout may also have tophaceous deposits within the skin or bursae of the extremities. Elevated urine pH, serum uric acid, and serum phosphate can all be associated with numerous conditions and are not specific to gout. Calcium pyrophosphate crystals are associated with chondrocalcinosis (pseudogout).

Skeletal survey is the most sensitive means of detecting lesions of eosinophilic granuloma (Langerhans cell histiocytosis). Bone scan detects most, but not all, of the lesions. Some lesions lack enough osteoblastic activity to appear on bone scan. Lesions are not detected on physical exam unless they are large enough to cause pain or tenderness. Indium labeled white cell studies are not used in this condition.

In the absence of any severe progressive neurologic deficits or other red flags, the most appropriate management for an acute lumbar disk herniation is nonsurgical care. Conservative treatments such as limited bed rest, anti-inflammatory medications, and judicious use of pain medications are appropriate in this clinical situation. Up to 90% of patients will experience a resolution of symptoms without the need for surgical intervention within a 3-month window. In the acute setting, with no neurologic deficits, immediate MRI of the lumbar spine is neither beneficial nor warranted. Likewise,without signs of an acute deficit, emergent surgical intervention and caudal epidural steroid injections are not needed.

The radiograph shows a displaced type II distal clavicle fracture with nonunion. Because the patient’s symptoms are minimal, the injury can be treated like a grade III acromioclavicular separation. Present management should consist of ice, anti-inflammatory drugs, activity modification, and perhaps physical therapy. If nonsurgical management fails to provide relief, the surgical options are varied with no uniformity in the literature regarding surgical treatment of this injury.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 271-286.
Craig EV: Fractures of the clavicle, in Rockwood CA Jr, Matsen FA III (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1998, vol 1, pp 428-482.

Stress fractures are the result of physiological bone response to increased stress. Increased stress on bone triggers an increase in remodeling, which begins with resorption of bone at the site of stress. Ongoing stress can overwhelm bone strength, resulting in a fracture. In the foot this most commonly is seen in the second metatarsal at the junction of the middle and distal thirds. Contributing factors to increased loading of the second metatarsal include hallux valgus (decreased hallux loading transfers to the second metatarsal head), hallux rigidus (offloading of the hallux attributable to pain increases second metatarsal loading), and a long second metatarsal (increased duration of contact during push-off in the stance phase).
# RECOMMENDED READINGS
Shindle MK, Endo Y, Warren RF, Lane JM, Helfet DL, Schwartz EN, Ellis SJ.
Stress fractures about the tibia, foot, and ankle. J Am Acad Orthop Surg. 2012 Mar;20(3):167-
[76/. doi: 10.5435/JAAOS-20-03-167. Review. PubMed PMID: 22382289. ](http://www.ncbi.nlm.nih.gov/pubmed/22382289)[View Abstract at](http://www.ncbi.nlm.nih.gov/pubmed/22382289)[ ](http://www.ncbi.nlm.nih.gov/pubmed/22382289)[PubMed](http://www.ncbi.nlm.nih.gov/pubmed/22382289)
[Donahue SW, Sharkey NA. Strains in the metatarsals during the stance phase of gait: implications for stress fractures. J Bone Joint Surg Am. 1999 Sep;81(9):1236-44. PubMed PMID: 10505520. ](http://www.ncbi.nlm.nih.gov/pubmed/10505520)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/10505520)

■
BMP is contraindicated for use in the anterior cervical spine. The U.S. Food and Drug Administration produced a warning to not use BMP in anterior cervical surgery due to a higher risk of death (secondary to soft-tissue swelling). When it is used in the lumbar spine, BMP results in lower reoperation rates, higher fusion, and greater cost efficacy when the cost of implants and reoperation are considered.

The patient has a very low T-type acetabular fracture; however, the head is not congruent under the dome so surgical reduction is necessary. The anterior and posterior columns are displaced and will move independent from each other. The extended iliofemoral is the only approach allowing for visualization and reduction of each column. A combined anterior and posterior approach may also be used. The timing of surgery should be within the first 3 weeks of injury to optimize chances of obtaining an accurate reduction because this is an important factor in determining outcome.
REFERENCES: Letournel E, Judet R (eds): Fractures of the Acetabulum, ed 2.
Berlin, Germany, Springer-Verlag, 1991.
Matta JM: Fractures of the acetabulum: Accuracy of reduction and clinical results in patients managed operatively within three weeks after the injury. J Bone Joint Surg Am
1996;78:1632-1645.

Parathyroid hormone, the active form of vitamin D (1,25 dihydroxyvitamin D), and calcitonin each have a net effect on calcium and phosphorus concentrations in extracellular fluid and serum:
Net Effect
Parathyroid hormone Increased serum calcium
Decreased serum phosphate
Vitamin D3 (1,25 dihydroxyvitamin D) Increased serum calcium
Increased serum phosphate
Calcitonin Decreased serum calcium
(transient)

- 6 weeks_

Injuries involving the distal femoral epiphysis cartilage plate are fairly common. Appropriate management should include a complete knee exam with a standard series of X-rays. Of particular importance is to notice any varus or valgus deformity. Stephens et al. (JBJS 1974:56A) measured varus and valgus deformities clinically and roentgenographically. A varus or valgus deformity greater than 3 degrees as compared with the uninjured side was considered clinically significant. Such deformities are highly suggestive of a physeal injury. A MRI may show the injury, but is expensive as is an arthroscopy or examination under anesthesia.

Knee disarticulation level is associated with the worst functional result 2 years after injury (compared to transmetatarsal, Symes, AKA, or BKA). The prosthetic use is decreased with a knee disarticulation as compared to a transtibial amputation.
The cohort study by MacKenzie et al prospectively followed 161 patients that were part of the Lower Extremity Assessment Project (LEAP). These patients underwent an above-the-ankle amputation at a trauma center within 3 months following the injury and followed for 2 years. This study revealed that through-the-knee amputations had significantly worse scores for the objective performance measures of self-selected walking speed, independence in transfers, walking, and stair-climbing. Through-the-knee amputees also had worse SIP scores than AKA and BKA patients. Physicians were also less satisfied with both the clinical and the cosmetic recovery of the patients with a through-the-knee amputation. It should be noted that patients with a BKA had a faster walking speed than those with an AKA. Despite the worse SIP scores for through-the-knee amputations, patients actually reported less pain than those with an AKA or BKA, though this wasn't statistically significant.

During surgical repair of a distal biceps tendon rupture, regardless of the surgical approach or technique, an understanding of the regional anatomy is important. The tendon passes distally into the antecubital fossa. The antecubital fossa is defined by the brachioradialis radially and the pronator teres ulnarly. A sheath surrounds the biceps tendon as it passes through the antecubital fossa toward its insertion on the radial tuberosity. The lateral antebrachial cutaneous nerve lies superficially in the subcutaneous tissue of the antecubital fossa. The nerve parallels the brachioradialis. While still superficial, the tendon is contiguous with the lacertus fibrosus that becomes confluent medially with the fascia overlying the flexor-pronator mass. The brachial artery lies just beneath the lacertus fibrosus at the level of the elbow flexion crease. The tendon travels just lateral (radial) to the median nerve within the antecubital fossa and passes posterior (deep) to the recurrent radial artery before it attaches to the radial tuberosity. Full forearm supination allows visualization of the tendinous insertion on the radial tuberosity.
RECOMMENDED READINGS
23. Leslie BM, Ranger H. Biceps tendon and triceps tendon ruptures. In: Baker CL, Plancher KD, eds. _Operative treatment of elbow injuries_. New York: Springer-Verlag; 2002:110-122.
24. [Eames MH, Bain GI, Fogg QA, van Riet RP. Distal biceps tendon anatomy: a cadaveric study. J Bone Joint Surg Am. 2007 May;89(5):1044-9. PubMed PMID: 17473142. ](http://www.ncbi.nlm.nih.gov/pubmed/17473142)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/17473142)

This patient sustained an isolated anterior cruciate ligament (ACL) injury based upon the mechanism described and examination findings. The finding that produces the “clunk” is the pivot-shift maneuver, which is positive in a knee with an incompetent ACL. With an ACL-deficient knee in full extension and internal rotation, the lateral tibial plateau subluxates anteriorly. As the knee is flexed, the lateral tibial plateau slides posteriorly into a reduced position, causing an audible clunk. Response D correctly describes the pathomechanics that result in the audible clunk heard during the pivot-shift maneuver. Responses A and B are incorrect because they describe the medial tibial plateau, which is not part of the pathomechanics of the pivot shift. Response C is incorrect because in extension, the lateral tibial plateau _is subluxated, not reduced._

The humerus was treated with an intramedullary nail. Findings from two prospective randomized studies of intramedullary nailing or compression plating of acute humeral fractures have shown approximately a 30% incidence of shoulder pain with antegrade humeral nailing. This is the most common complication in both of these series. Nonunions are present in approximately 5% to 10% of humeral fractures treated with an intramedullary nail. Infection has an incidence of approximately 1%. Elbow injury is unlikely unless the nail is excessively long. Rarely, injury to the radial nerve is possible if it is trapped in the intramedullary canal.
REFERENCES: Chapman JR, Henley MB, Agel J, et al: Randomized prospective study of humeral shaft fracture fixation: Intramedullary nails versus plates. J Orthop Trauma 2000;14:162-166.
McCormack RG, Brien D, Buckley RE, et al: Fixation of fractures of the shaft of the humerus by dynamic compression plate or intramedullary nail: A prospective, randomised trial. J Bone Joint Surg Br 2000;82:336-339.

Radial head fractures are thought to occur as a result of valgus posterolateral rotary load across the elbow, although the mechanism can certainly vary. Minimally or nondisplaced fractures without any clinical instability or block to motion can often be successfully managed non-surgically. Fractures with >2 mm of displacement or fragments that block motion require surgical repair. A critical aspect during surgery is identifying concomitant injury to the lateral collateral ligament complex (LCL). When encountered, the LCL is most often avulsed from its origin at the lateral epicondyle, resulting in a bare area. After the radial head is either repaired or replaced (Figures 4 and 5), the LCL should
16
be repaired back to its anatomic origin. Postoperatively, the surgeon must communicate to the therapist that elbow extension exercises should be performed with the forearm in pronation as a result of the compromised LCL, as this position places the least stress on the ligamentous repair. Elbow extension exercises in supination or neutral are recommended for compromise of the medial collateral ligament, or combined medial and lateral ligament injury, respectively. Without any medial elbow bruising, swelling, or tenderness, it is unlikely that the patient has an injury to the medial collateral ligament.

Postoperative wound infections following total joint arthroplasty are generally classified as acute or chronic. The time period is either 2 or 4 weeks from the time of implantation depending on whom you read. This will, generally, determine if you can attempt a one-stage procedure. The other considerations are the bacteria’s resistance to antibiotics and whether or not it produces glycocalyx. If the microorganism elaborates glycocalyx it is highly likely that it will remain after surgical removal of the implants and debridement of the joint.
Present recommendations are to avoid a one-stage reconstruction in a patient in whom a glycocalyx elaborating microorganism has been isolated. In one study 52% of the isolates of S. epidermidis and 28% of the isolates of S. aureus elaborated glycocalyx. The microbiology laboratory can be asked to determine if the microorganisms elaborate glycocalyx. In the present case it should be assumed that the staphylococci elaborate glycocalyx and are resistant to antibiotics. A two-stage procedure is indicated for these reasons alone.
Antibiotic therapy alone has been used for a select group of patients who could not medically tolerate either a one-stage or a two-stage arthroplasty. The patient in this case is listed as otherwise healthy.
The decision to perform a resection arthroplasty as a definitive procedure without reimplantation is based on the bacteria’s resistance to antibiotics, quality of the local soft tissues, the complexity of the reconstruction, the patient’s refusal to have another operation, the patient’s overall health, or a combination of these factors. None of which appear to be present in this case.

C hildren ages 4 to 8 (40 lbs to 60 lbs) are at risk for airbag injuries and should not be in the front seat. In addition, they require booster seats to allow proper fitting of the shoulder harness on the upper torso. Rear-facing seats are only appropriate for infants. C hildren should not be in the front seat until after age 12 and over 100 lbs.

Internal impingement of the shoulder is now a well-recognized cause of shoulder pain in the throwing athlete. First described by Walch and associates, it involves contact of the rotator cuff and labrum in the maximally externally rotated and abducted shoulder, such as in the late cocking phase of the throwing motion. Schickendantz and associates have shown this contact to be physiologic in most patients and becoming pathologic with repetitive overhead activity.
REFERENCES: Schickendantz MS, Ho CP, Keppler L, Shaw BD: MR imaging of the thrower’s shoulder: Internal impingement, latissimus dorsi/subscapularis strains, and related injuries. Magn Reson Imaging Clin N Am 1999;7:39-49.
Walch G, Boileau P, Noel E, et al: Impingement of the deep surface of the supraspinatus tendon on the posterosuperior glenoid rim: An arthroscopic study. J Shoulder Elbow Surg 1992;1:238-245.
McFarland EG, Hsu CY, Neira C, O’Neil O: Internal impingement of the shoulder: A clinical and arthroscopic analysis. J Shoulder Elbow Surg 1999;8:458-460.

Margin convergence refers to the phenomenon that occurs with side-to-side closure of large U- or L-shaped rotator cuff tears in which the free margin of the tear converges toward the greater tuberosity as the side-to-side tear progresses. The creation of the converged cuff margin creates decreased strain in the free margin of the repaired cuff, resulting in a decreased strain in the repair sutures. While the size of the humeral head defect is made smaller with side-to-side closure, biomechanically, this is less significant. The mild increase in thickness of the repair at the side-to-side margin is less important than a reduction in stress in the repaired tissue. Stress in the crescent cable region of the cuff actually increases and becomes more physiologic in transmitting force from the cuff to the greater tuberosity.
REFERENCES: Burkhart SS: A stepwise approach to arthroscopic rotator cuff repair based on biomechanical principles. Arthroscopy 2000;16:82-90.
Burkhart SS, Athanasiou KA, Wirth MA: Margin convergence: A method of reducing strain in massive rotator cuff tears. Arthroscopy 1996;12:335-338.

Open fractures in children have similar rates of short-term complications such as compartment syndrome, vascular injury, and nerve injury when compared to adult fractures. Primary wound closure should be used for Gustillo and Anderson type 1 or uncomplicated type 2 fractures after surgical debridement. Skeletal stabilization may consist of external fixation, flexible nails, or casting with or without supplementary pin fixation. For an open comminuted midshaft fracture, external fixation is the treatment of choice. Reamed intramedullary nailing is contraindicated in children with an open physis. Plate fixation has a high complication rate in severe open fractures.
REFERENCES: Jones BG, Duncan RD: Open tibial fractures in children under 13 years of age-10 years experience. Injury 2003;34:776-780.
Bartlett CS III, Weiner LS, Yang EC: Treatment of type II and type III open tibia fractures in children. J Orthop Trauma 1997;11:357-362.
Robertson P, Karol LA, Rab GT: Open fractures of the tibia and femur in children. J Pediatr Orthop 1996;16:621-626.
Cullen MC, Roy DR, Crawford AH, et al: Open fracture of the tibia in children. J Bone Joint Surg Am 1996;78:1039-1047.

Multiple studies have confirmed that cam or pincer anatomy is commonly present in asymptomatic hips. According to a large systematic review, cam deformities are present in approximately one-third of asymptomatic hips in young adults, and the proportion is higher than 50% in the subgroup of athletes. Ganz and associates proposed that femoral acetabular impingement is the root cause of osteoarthritis in most nontraumatic, nondysplastic hips, and functional improvement with surgical correction of the deformity has been demonstrated. Despite the link between cam deformity and hip osteoarthritis, a corresponding link between the correction of the deformity and prevention of osteoarthritis has never been proven. The results of cam deformity correction, typically including repair of the degenerative labral tear, are much poorer when substantial joint space loss is present. A typical joint space cutoff of 2 mm or less is used to recommend against hip preservation surgery.

## RESPONSES FOR QUESTIONS 25 THROUGH 27
1. Radiation
2. Ethylene oxide
3. Remelting
4. Annealing
## Ultra-high-molecular-weight polyethylene (UHMWPE) is a commonly used polymer in total hip and knee replacement. Please refer to the list of terms above in reference to UHMWPE and select the most appropriate response to the questions below.

The patient’s history, examination, and radiographs are classic for locked posterior dislocation of the glenohumeral joint. Posterior dislocation of the shoulder remains the most commonly missed dislocation of a major joint. Up to 80% are missed on initial presentation. The primary cause for failure to accurately diagnose this injury is inadequate radiographic evaluation. The typical presentation is a shoulder locked in internal rotation with loss of abduction. An axillary view not only will make the definitive diagnosis but will help assess the size of the articular surface defect and help plan treatment. This view can be done expediently as part of every trauma series. The AP view is suspicious for a posteriorly dislocated humerus with loss of the humeral neck profile, a vacant glenoid sign, and an anterior humeral head compression fracture (reverse Hill-Sachs lesion).
REFERENCES: Hawkins RJ, Neer CS II, Pianta RM, Mendoza FX: Locked posterior dislocation of the shoulder. J Bone Joint Surg Am 1987;69:9-18.
Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow. Rosement, IL, American Academy of Orthopaedic Surgeons, 1997, pp 181-189.
Rockwood CA Jr, Thomas SC, Matsen FA III: Subluxations and dislocations about the glenohumeral joint, in Rockwood CA Jr, Green DP, Bucholz RW (eds): Fractures in Adults, ed 3. Philadelphia, PA, JB Lippincott, 1991, vol 1, pp 1058-1065.

The Hospital for Special Surgery knee score and the Knee Society score provide more detailed information about the physical dynamics of a prosthesis than the WOMACscore. A combination of the three scores correlate well in their measurement of total knee replacement outcomes

Figures 14a through 14e show a 13-year-old boy with osteomyelitis of the distal tibia and a large subperiosteal abscess. The patient has failed treatment with IV ceftriaxone, and methicillin-resistant Staphylococcus aureus infection is likely. Aspiration, cultures, irrigation and debridement, IV vancomycin, an infectious disease consult, and an evaluation for possible deep vein thrombosis is prudent initial treatment. Figure 15a through 15c show a 7-year-old girl who sustained a deer tick bite while vacationing in Connecticut. She has Lyme arthritis and a Lyme “bulls-eye” rash on the same leg. Aspiration, cultures, Lyme serology, and oral amoxicillin for 30 days is prudent initial treatment. Figures 16a and 16b are the radiograph and MR image of a 15-year-old dance athlete with a probable minor fracture via a benign cyst of the distal femur. The geographic cyst may be a nonossifying fibroma, eosinophilic granuloma, Brodie abscess, or simple bone cyst. Biopsy, culture, curettage and bone graft, and possible internal fixation is reasonable initial treatment.


Figure 17

**
An occurrence policy provides coverage for all claims made during employment irrespective of when it is filed (during or postemployment) and therefore is the best option. Claims made policy only covers suits for the time employed. A prepurchased "tail" is needed to provide coverage for cases that occurred during employment but filed postemployment. Nose coverage is applicable if the surgeon was previously employed and did not have tail coverage from previous employment, but this surgeon just emerged from training where it is not applicable. Claims made without tail coverage is unwise because the surgeon would be unprotected or have to purchase his own policy postemployment.
Only in certain situations does sovereign immunity exist, and generally not in a for-profit system. Occurrence coverage with nose coverage
is incorrect because it does not apply to this surgeon with no previous employment or claims policy lacking tail coverage.

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#### Duchenne muscular dystrophy is a recessive, X-linked, inherited disorder. Most (90%) untreated boys with this disorder develop progressive scoliosis, secondary to muscle weakness, after becoming full-time wheelchair users. Several studies suggest that the long-term use of glucocorticoids has prolonged effects against detrimental aspects of Duchenne muscular dystrophy.
#### The widespread use of glucocorticoids for patients with Duchenne muscular dystrophy has dramatically decreased the development of scoliosis and need for subsequent surgical intervention. There is still much to be learned about the impact of glucocorticoids on the spine, including the duration of glucocorticoid treatment needed to reduce the risk of a progressive curve and whether this treatment merely delays the onset. In recent studies in which researchers followed young men into their twenties, it was shown that glucocorticoids protect against the development of scoliosis well past skeletal maturity.
#### Posterior spinal instrumentation and fusion are recommended in those whose spinal curve is >20°, are prepubertal, and are not on glucocorticoids because progression of the curve is expected. Although patients taking glucocorticoids may still develop a scoliosis, it is reasonable to wait until progression is documented. When surgery is done to correct scoliosis, it is recommended that those with a pelvic obliquity of >15° also have stabilization and fusion into the pelvis. This helps patients with seating and positioning. Fusion to the L5 is sufficient for patients who do not have a severe pelvic obliquity. With surgical intervention of the spine, the aim is to reduce the patient’s pain, improve his ability to sit comfortably, and prevent further progression.
####

Osteolysis of this magnitude is uncommon in the setting of an uncemented hemiarthroplasty. Further workup for infection is indicated, such as aspiration under fluoroscopy or ultrasound. Infection needs to be ruled out before proceeding. Observation and physical therapy are not indicated. Arthroscopy has been shown in several studies to have greater sensitivity and specificity than aspiration and can be especially effective to obtain cultures of slow-growing organisms such as Propionibacterium acnes. Blood tests are unreliable, and a bone scan would not reliably differentiate between loosening and infection. Arthroscopic debridement would not be reliable for treatment. Intravenous antibiotics can be used for suppression, but the best results in terms of resolving the infection would be achieved with 2-stage revision.
RECOMMENDED READINGS
31. [Dilisio MF, Miller LR, Warner JJ, Higgins LD. Arthroscopic tissue culture for the evaluation of periprosthetic shoulder infection. J Bone Joint Surg Am. 2014 Dec 3;96(23):1952-8. doi: 10.2106/JBJS.M.01512. PubMed PMID: 25471909. ](http://www.ncbi.nlm.nih.gov/pubmed/25471909)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/25471909)
32. Hersch JC, Dines DM. Arthroscopy for failed shoulder arthroplasty. Arthroscopy. 2000 Sep;16(6):606-
[12/. PubMed PMID: 10976121. ](http://www.ncbi.nlm.nih.gov/pubmed/10976121)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/10976121)
33. [Foruria AM, Fox TJ, Sperling JW, Cofield RH. Clinical meaning of unexpected positive cultures (UPC) in revision shoulder arthroplasty. J Shoulder Elbow Surg. 2013 May;22(5):620-7. doi: 10.1016/j.jse.2012.07.017. Epub 2012 Sep 13. PubMed PMID: 22981448. ](http://www.ncbi.nlm.nih.gov/pubmed/22981448)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/22981448)

Injuries to the ulnar collateral ligament of the MCP joint of the thumb commonly occur in recreational skiers. Historically, this injury has been referred to as “gamekeeper’s thumb.” The ligament consists of the proper collateral ligament and the more volar accessory collateral ligament. In extension, the accessory ligament is taut, and in flexion, the proper ligament is taut. For a complete tear of the ligament complex to occur, there must be laxity in full extension. Incomplete tears respond well to thumb spica splinting or casting for 2 to 3 weeks and gradual resumption of range of motion. Prolonged immobilization of incomplete injuries leads to higher rates of MCP joint stiffness.
REFERENCES: Stener B: Displacement of the ruptured ulnar collateral ligament of the metacarpo-phalangeal joint of the thumb: A clinical and anatomical study. J Bone Joint Surg Br 1971;44:869.
Heyman P: Injuries to the ulnar collateral ligament of the thumb metacarpophalangeal joint.
J Am Acad Orthop Surg 1997;5:224-229.

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##### DISCUSSION: A limbus or apophyseal fracture caused by heavy lifting or twisting is commonly seen in older children and adolescents. Patients describe feeling a popping sensation and report radicular symptoms. Radiographs usually are not sufficient to diagnose the injury. MRI or CT should be used to determine the exact location of the fracture. Nonsurgical management is rarely successful. A wide laminectomy with surgical excision of the limbus fragment is recommended if neurologic symptoms are present.
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##### REFERENCE: Fischgrund JS (ed): Orthopedic Knowledge Update 9. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2008, p 694.
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##### **2010 Pediatric Orthopaedic Examination Answer Book • 13**
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##### Figure 8
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Numerous risk factors for stress fracture exist. Most commonly, the scenario is doing âtoo much too soon.â Survey data have shown 86% of runners suffering stress fracture have had a change in duration, frequency, or intensity of training immediately prior to injury. The best independent predictors for stress fracture development in women appear to be age of menarche and calf girth

Talar neck and body fractures can be difficult to distinguish, especially when they extend superiorly into the anteromedial aspect of the trochlea. These two fractures have a different prognosis. The authors recommend classification of these fractures based on the inferior fracture line; if anterior to lateral process of the talus, then it is a neck fracture; if posterior to lateral process of the talus, then it is a body fracture.

The calcaneus fracture is associated with subluxation of the subtalar joint, giving the appearance of injury to the talus and calcaneus. The true extent of the injury cannot be determined without a computed tomography scan; however, the question is not as to the outcome of treatment, but the ability to return this patient to his occupation. At 4 weeks following injury, while open reduction internal fixation of the fracture is possible, anatomic reduction may be difficult. The most likely means of returning this patient to work is with early arthrodesis, which should be combined with an open reduction internal fixation of the calcaneus.

This patient has a right posterior sternoclavicular (SC) dislocation. Management involves closed reduction and bracing. Closed reduction should be performed with a thoracic surgeon available in the event of mediastinal involvement.
The SC joint can dislocate anteriorly or posteriorly. Posterior dislocations are first treated with closed reduction. If closed reduction fails, open reduction is indicated. Early complications of posterior SC dislocation include pneumothorax, laceration/erosion/occlusion of great vessels, esophageal rupture and brachial plexus compression. Late complications include tracheoesophageal fistula, stridor and dysphagia.
Groh et al. reviewed traumatic SC injuries. Reduction maneuvers in posterior SC dislocation include: (1) traction on the arm and slowly bringing it into extension, (2) traction with the arm in adduction and posterior pressure applied to the shoulder, and (3) pulling anteriorly on a towel clip encircling the medial clavicle. Chronic instability after posterior SC dislocations can be managed with figure-of-8 semitendinosus graft or medial clavicle resection and reattachment of the clavicle to the first rib with dacron tape.
Glass et al. performed a systematic review on SC dislocations. They found mediastinal compression occurred 30% of the time with posterior dislocations.
Figures A and B are radiographs demonstrating asymmetry of the SC joints, characteristic of a right posterior SC dislocation (Figure B is not a serendipity view). Illustration A demonstrates how in POSTERIOR dislocation, the clavicle appears INFERIOR, and in ANTERIOR dislocation, the clavicle appears SUPERIOR on a serendipity view radiograph respectively. Illustration B shows the imaging technique for a serendipity view radiograph. Illustration C is a reconstructed CT image of the patient showing left posterior SC dislocation.
Incorrect Answers:
Answer 1: Nonsurgical management is not advised because of potential complications of posterior dislocations. Unstable dislocations will remain dislocated at 6 weeks if untreated.
Answer 2: Closed reduction in the emergency room is ill-advised because of potential mediastinal involvement. An operating room and thoracic surgeon should be available during the reduction maneuver.
Answer 4: Compression plating across the sternoclavicular joint is not recommended.
Answer 5: Pinning with K-wires is contraindicated because of potential catastrophic consequences of wire migration.

The patient underwent an ACL reconstruction that has now failed. Based on his examination, he also has a posterolateral corner injury. Because this concomitant injury was not treated, the patient had undue strain on his graft, resulting in ultimate failure. Hamstring grafts are as effective as other graft types for ACL reconstruction. The medial meniscus provides secondary stabilization to the knee; however, this patient has a missed lateral ligamentous injury, and meniscus tears do not result in the development of a varus thrust. An unrecognized PCL tear likely results in mild-to-moderate medial and patellofemoral osteoarthritis without significant lateral laxity and thrust.
39

The patient has painful lateral and plantar keratoses with metatarsus quintus valgus deformity. This combination of problems is best addressed with an oblique mid-diaphyseal osteotomy that allows the distal metatarsal to be displaced medially and dorsally. Lateral eminence resection alone will not address the painful plantar keratosis. A distal chevron osteotomy has a more limited ability to address the plantar keratosis (if translated medially and slight dorsally). Proximal diaphyseal osteotomies of the fifth metatarsal are associated with an increased risk of delayed union or nonunion secondary to the relative hypovascularity in the proximal diaphysis. Excision of the fifth metatarsal head can result in a floppy fifth toe and transfer metatarsalgia.
REFERENCES: Coughlin MJ: Treatment of bunionette deformity with longitudinal diaphyseal osteotomy with distal soft tissue repair. Foot Ankle 1991;11:195-203.
Moran MM, Claridge RJ: Chevron osteotomy for bunionette. Foot Ankle Int 1994;15:684-688.

The SLIL is a c-shaped structure, which is thickest dorsally. The dorsal fibers have an average thickness of 3 mm and are composed of transversely oriented fibers, which afford the greatest resistance to translation between the scaphoid and the lunate, preventing the characteristic radiographic separation and flexion deformity of the scaphoid.

The elbow usually is stable after reduction in most elbow dislocations. Ross and associates reported that supervised motion begun immediately after reduction was effective in uncomplicated dislocations. The elbow will become stiff if immobilization is applied for an extended period of time. Immediate open treatment is not indicated for a simple elbow dislocation.
REFERENCES: Ross G, McDevitt ER, Chronister R, et al: Treatment of simple elbow dislocation using an immediate motion protocol. Am J Sports Med 1999;27:308-311.
O’Driscoll SW, Jupiter JB, King GJ, et al: The unstable elbow. J Bone Joint Surg Am 2000;82:724-738.

Loss of nerve electrical conduction begins after 2 hours of complete ischemia. Peripheral nerves can tolerate up to 4 hours of complete ischemia. A neurapraxic (loss of conduction capability) injury usually recovers. After 8 hours of complete ischemia, nerves cannot recover.
Patients will lose the sense of pain in a compartment with total ischemia after 2 to 8 hours because there is no conduction to the nerve. One can expect little recovery once this painless state has occurred.

Type II collagen fibers resist tensile and shear deformation forces in the articular cartilage.
In contrast, the glycosaminoglycan aggregates resist articular cartilage compression and fluid flow.

- a PITX1 mutation.

Interferon gamma-1 is the only treatment for osteopetrosis that is approved by the Food and Drug Administration

The patient has a symptomatic cartilage lesion of his medial femoral condyle, which has not responded to nonsurgical measures, and he failed a prior arthroscopy with debridement. Based on his examination and imaging, he is ligamentously stable, has normal mechanical alignment, and has intact menisci, making him a candidate for a cartilage restoration procedure. The accompanying MRI also indicates subchondral bone involvement with increased T2 signal underlying the cartilage defect. Osteochondral allograft is the only choice that addresses both the cartilage defect, as well as compromised subchondral bone. Depending on lesion size, osteochondral autograft transfer may also be considered, but this is not presented as an answer choice.Given the radiographic finding of neutral mechanical alignment, bracing would be less effective, and the patient has already tried extensive physical therapy. Lack of malalignment also excludes tibial osteotomy as a preferred answer choice. Microfracture is best for small cartilage lesions without _significant bone marrow involvement._