Advanced Insights into Distal Radius Fractures: Epidemiology, Classification, Anatomy & Biomechanics

- Index proximal IP flexion

The radiograph shows a posterior wall acetabular fracture-dislocation. Post reduction CT indicates a large comminuted posterior wall fracture with marginal impaction of the articular surface. A comminuted femoral head fracture also is seen extending to the superior weight-bearing surface. Given the marginal
impaction of the acetabulum and the considerable comminution of the femoral head (which is likely unreconstructible), this injury would have a high risk of causing posttraumatic arthritis if treated with ORIF of the fractures alone. Considering this fact and the patient’s age, ORIF of the posterior wall and acute total hip arthroplasty would likely have the best functional result and the lowest risk of reoperation. Hemiarthroplasty is inappropriate for this injury considering the acetabular fracture. Skeletal traction currently plays a limited role in the definitive treatment of acetabular fractures.

The most common nerve that has been found to have a deficit after shoulder arthroplasty is the axillary nerve. Correct Answer: Axillary nerve

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Workers’ compensation is a system that provides healthcare and wage-replacement benefits for workers injured in the occupational setting. Back pain is the most common workers compensation claim in the United States, accounting for up to 25% of all claims and one-third of total compensation costs. Numerous studies have reported that workers’ compensation is an independent negative risk factor for unsatisfactory outcomes after surgical procedures.
Keeney and associates published a prospective study looking at which factors were predictive for proceeding to surgery in the workers’ compensation population. Their findings showed that young age (<35 years-old), female gender, and Hispanic ethnicity were negative predictive factors for proceeding with surgical treatment. Which medical professional the work compensation patient sought made a difference; nearly 43% of injured workers whose first visit was to a surgeon eventually underwent a surgical procedure.

**
The patient has gout. Unfortunately, gout may mimic several conditions affecting the small joints of the hand, including infection. The histologic specimen shows negatively birefringent intracellular rods consistent with gout. The histology rules out giant cell tumor and calcium pyrophosphate deposition disease.

Compartment syndrome can often be difficult to diagnosis in the pediatric patient. Mechanism of injury is not the best predictor of compartment syndrome development or diagnosis in pediatric patients. It is important to note that functional outcome following compartment syndrome in patients is inversely related to the duration of elevated tissue pressures before surgical fasciotomy.
Level 4 evidence by Bae et al reviewed 33 children with compartment syndrome. They found that all 10 compartment syndrome patients that had access to nurse or patient controlled analgesia (PCAs), during their initial evaluation, demonstrated an increasing requirement for pain medication.
Matsen et al reviewed 24 children with compartment syndrome with the most common causes being fracture, vascular injury, and tibial osteotomy. The study concluded that is imperative that a compartment syndrome be identified and treated as promptly as possible.

DISCUSSION: In open fractures, the hematoma that forms beneath the periosteum and around the ends of the fracture site is lost from the open wound. In addition, the irrigation process washes out the hematoma that contains growth factors and cytokines from the platelets. While loss of blood supply at the fracture site and soft-tissue coverage are important factors, the most important is loss of the factors that initiate the inflammatory phase of fracture healing. Infection may also delay healing, but is less common in this population.
REFERENCES: Buckwalter JA, Einhom TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 377-381.
Green NE, Swiontkowski MF (eds): Skeletal Trauma in Children, ed 3. Philadelphia, PA, WB Saunders, 2003, pp 1-14.

2010 Pediatric Orthopaedic Examination Answer Book • 57

Compression plating remains the treatment of choice for most established humeral nonunions. Autograft is felt to be superior to allograft. Electrical stimulation has not been found to improve healing rates in patients with nonunion after intramedullary nailing. Retrograde nailing with flexible nails gives inadequate rotational control to promote healing in this patient. Adding cancellous graft alone will not stabilize the nonunion site. Dynamic locking has been successful only in the lower extremity because the bone can be loaded axially.
REFERENCES: McKee MD, Miranda MA, Riemer BL, et al: Management of humeral nonunion after the failure of locking intramedullary nails. J Orthop Trauma 1996;10:492-499.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 271-286.

The MRI scan reveals a posterior labral detachment. This injury is the result of a posteriorly directed force and is common to football players in blocking positions. Although this injury can occur with trauma in all types of athletes, it is seen with relative frequency in football. Treatment is aimed at labral repair with posterior capsulorrhaphy. Both open and arthroscopic techniques can be used.
REFERENCES: Misamore GW, Facibene WA: Posterior capsulorrhaphy for the treatment of traumatic recurrent posterior subluxations of the shoulder in athletes. J Shoulder Elbow Surg 2000;9:403-408.
Mair SD, Zarzour RH, Speer KP: Posterior labral injury in contact athletes. Am J Sports Med 1998;26:753-758.

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)

The most common side effect of an interscalene block is ipsilateral phrenic nerve blockade. The phrenic nerve arises chiefly from the fourth cervical ramus (with contributions from the third and fifth) and is the sole motor supply to the diaphragm. Phrenic nerve palsy usually is well tolerated in healthy patients but should be avoided in patients with limited pulmonary function (severe restrictive or obstructive lung disease, myasthenia gravis, or contralateral hemidiaphragmatic dysfunction). The incidence of ipsilateral phrenic nerve blockade afer interscalene block approaches 100%.
REFERENCES: Long T, Wass C, Burkle C: Perioperative interscalene blockade: An overview of its history and current clinical use. J Clin Anesthesia 2002;14;546-556.
Norris T (ed): Orthopaedic Knowledge Update: Shoulder and Elbow 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 433-442.

The arthritis in this joint is not severe, but there is joint malalignment associated with a short and externally rotated fibula. Joint malalignment is correctable with a lengthening and rotational (internal) osteotomy of the fibula with bone graft. Joint debridement, either open or arthroscopic, is not effective in the management of posttraumatic ankle arthritis. Arthrodesis and arthroplasty are not necessary at this stage.

DISCUSSION: Increased irradiation doses cause a decrease in the mechanical properties of the polyethylene, resulting in a decrease in ultimate tensile strength, fracture toughness, and resistance to crack propagation.
Irradiation leads to the production of free radicals, requiring a step in the manufacturing process (melting, annealing, vitamin E doping) to stabilize the free radicals and reduce the potential for oxidation. Wear resistance is improved with irradiation; however, there is minimal benefit with doses of greater than 10 Mrads.

REFERENCES: Collier JP, Currier BH, Kennedy FE, et al: Comparison of cross-linked polyethylene materials for orthopaedic applications. Clin Orthop Relat Res 2003;414:289-304.
Gordan AC, D’Lima DD, Colwell CW Jr: Highly cross-linked polyethylene in total hip arthroplasty. J Am Acad

Orthop Surg 2006;14:511-523.
Jacobs CA, Christian CP, Greenwald AS, et al: Clinical performance of highly cross-linked polyethylenes in total hip arthroplasty. J Bone Joint Surg Am 2007;89:2779-2786.

The patient has an acute postoperative fracture of the proximal femur with subsidence. It is also common that the stem retroverts relative to the femur. It is most often seen in proximally porous coated stems within 90 days of surgery, one paper found it to occur 0.7% of the time in modern implants. There is always a debate whether this is a missed intraoperative fracture, or a new fracture that has resulted from an event of increased hoop stresses. Removal of the primary stem, placement of a diaphyseal engaging
stem (most frequently a tapered-fluted stem), and cabling of the fracture is the most successful treatment.

Synovial sarcoma is a soft-tissue sarcoma that usually occurs in young adults. Synovial sarcoma often causes pain, unlike most soft-tissue sarcomas, which generally do not cause pain. Imaging characteristics include soft-tissue calcifications on plain radiographs and a heterogeneous mass that is generally isointense to muscle on T1-weighted images and hyperintense to muscle on T2-weighted images. There are biphasic and monophasic types of synovial sarcoma. The biphasic
type, which is depicted here, has both spindle cell and epithelial components and will stain for both vimentin and cytokeratin. More than 90% of patients with synovial sarcoma have a characteristic genetic translocation of t(X;18), which results in the fusion protein SS18-SSX. This translocation can be stained for use of florescence in situ hybridization technology. t(11;12) is seen in Ewing sarcoma. T(9;22) is seen in extraskeletal myxoid chondrosarcoma. t(12;16) is seen in myxoid liposarcoma.
RECOMMENDED READINGS
9. [Nielsen TO, Poulin NM, Ladanyi M. Synovial sarcoma: recent discoveries as a roadmap to new avenues for therapy. Cancer Discov. 2015 Feb;5(2):124-34. ](http://www.ncbi.nlm.nih.gov/pubmed/25614489)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/25614489)
10. [Thway K, Fisher C. Synovial sarcoma: defining features and diagnostic evolution. Ann Diagn Pathol. 2014 Dec;18(6):369-80. doi: 10.1016/j.anndiagpath.2014.09.002. Epub 2014 Oct 13. Review. PubMed PMID: 25438927.](http://www.ncbi.nlm.nih.gov/pubmed/25438927)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/25438927)

This patient had mild median parasthesias preoperatively that have significantly worsened postoperatively. Immediate carpal tunnel release is the most appropriate next step in treatment.
Mack et al reported on ten cases of acute carpal tunnel syndrome (ACTS) and six cases of nerve contusion in patients with acute median neuropathy associated with blunt wrist trauma. The patients with ACTS initially had normal sensation and subsequently developed objective sensory loss (2-point discrimination greater than 15 mm) in the median nerve distribution associated with severe wrist pain. In contrast, patients with nerve contusion injuries had immediate sensory loss and symptoms were nonprogressive. Four of five patients with ACTS who underwent carpal tunnel release within 40 hours of the onset of numbness had normal 2-point discrimination within 96 hours.
Neuropathy, secondary to nerve contusion without coexisting ACTS, may be treated initially by observation.
Ford et al reported of five cases of ACTS. Four with delayed treatment had poor outcomes while the one patient with early CTR had full recovery. All patients with ACTS had increasing and severe pain in the wrist with parasthesia and impaired sensation in the median distribuation. These symptoms initially weren’t present after wrist trauma, but developed rapidly in the next few hours.

This MRI presents the typical appearance of an anterior tibial tendon rupture. There is no continuity of the tendon distally, and the retracted tendon end has formed a scar palpable as a subcutaneous mass. The clinical history of the weakness associated with a drop foot gait is characteristic of the tendon rupture.

Humerus fractures account for 11% of all fractures among snowboarders and are the second-most-common upper-extremity fracture after radius fractures (48%). Surgical fixation is recommended for fractures with residual displacement >5 mm, or >3 mm in active patients involved in frequent overhead activity. Malunion can result in a mechanical block to shoulder abduction or external rotation and altered rotator cuff mechanics, causing weakness. A rich arterial network provides a favorable healing environment for greater tuberosity fractures. Consequently, nonunion and osteonecrosis are uncommon.

Although hemiphyseal stapling is an acceptable option to correct radial articular angulation, in this boy the distal radial physis is already fused as is seen in the first radiograph.

The distal tibia grows more than the distal fibula.
The anterolateral portion of the tibial physis ceases growing last, thus explaining the phenomenon of the Tillaux fracture. The physis of the distal fibula is always located more distally than the distal tibia.
The two physes are not conjoined.

**
Locking screw fixation is a relatively new option in the armamentarium of orthopaedic surgeons treating fractures. The understanding of the biomechanics, implications to healing, and optimal indications and surgical techniques is still in evolution. A periprosthetic proximal femur fracture with a stable prosthesis is best treated with open reduction and internal fixation with locking proximal fixation with or without cerclage cables. Diaphyseal fractures treated with compression plating or bridge plating can be treated well with conventional implants unless osteoporosis is severe. An AO/OTA B-type partial articular fracture is also better suited to standard buttress plating with periarticular rafting lag screws. Locking fixation is not always required for a transverse displaced midshaft clavicle fracture.

The initial radiographs reveal a fourth and fifth carpometacarpal (CMC) joint fracture dislocation. The injury is associated with a shear fracture of the dorsal rim of the hamate. Further assessment with CT might be helpful in fully evaluating the extent of injury. Extensor carpi ulnaris is a deforming force at the base of the fifth metacarpal. This unstable fracture dislocation could be treated with closed reduction and pinning if the patient presented within a few days of injury. However, because he presented in a delayed fashion (3 weeks after injury), open reduction with internal fixation was required (Figures 4 and 5). In the series by Zhang and associates, patients with fourth and fifth CMC fracture dislocations presenting in a delayed fashion and treated nonsurgically had suboptimal results. Therefore, closed reduction and casting are not appropriate. An arthrodesis and resection arthroplasty are salvage procedures considered for a painful arthritic joint and would less likely should not be considered for this acute injury.

The cause of osteoarthritis is unknown. From a chemical standpoint, one of the earliest findings is a decrease in the proteoglycan and an increase in the water content. One should remember:
C onstant type II collagen content
Decreased proteoglycan concentration and decreased chain length
Increased water content
The decreased proteoglycan content results in increased permeability of the cartilage. A reduction of the stiffness makes the articular cartilage less able to bear loads.

The radiographs show nonunion of both the greater and lesser tuberosities. Tuberosity pull-off and nonunion remain among the most common causes of failed humeral head arthroplasty for fracture. Strict attention to securing the tuberosities to each other and to the shaft, and autogenous bone grafting from the excised humeral head will decrease the incidence of pull-off and improve healing rates. Active-assisted range-of-motion and strengthening exercises should be delayed until tuberosity healing is noted radiographically, usually at 6 to 8 weeks postoperatively.
REFERENCES: Hartsock LA, Estes WJ, Murray CA, et al: Shoulder hemiarthroplasty for proximal humeral fractures. Orthop Clin North Am 1998;29:467-475.
Hughes M, Neer CS: Glenohumeral joint replacement and postoperative rehabilitation.
Phys Ther 1975;55:850-858.
Compito CA, Self EB, Bigliani LU: Arthroplasty and acute shoulder trauma. Clin Orthop 1994;307:27-36.

The MRI findings reveal age-related degenerative changes in the cervical spine, which is a very common finding in the adult population. Boden and associates evaluated cervical spine MRI findings on 63 asymptomatic subjects, and found that the prevalence of having at least one degenerative disk was approximately 57% in those older than age 40 years.

Fibrous dysplasia is a common benign skeletal lesion that may involve 1 bone (monostotic) or multiple bones (polyostotic) and occurs throughout the skeleton with a predilection for the long bones. The radiographic features of fibrous dysplasia typically illustrate a grayish “ground-glass” pattern that is similar to the density of cancellous bone. The key histologic features of fibrous dysplasia are trabeculae of immature bone, with no osteoblastic rimming, contained within a bland fibrous stroma of dysplastic spindle-shaped cells without any cellular features of malignancy. The etiology of fibrous dysplasia has been linked to an activating mutation in the gene that encodes the a subunit of stimulatory G protein located at 20q13.2-13.3. This leads to a constitutive activation of adenylate cyclase and increased cyclic adenosine monophosphate formation. FGFR3 mutations are associated with achondroplasia. COMP mutations are associated with pseudoachondroplasia and multiple-epiphyseal dysplasia. EXT-1 mutations are associated with multiple hereditary exostosis.
RECOMMENDED READINGS
39. [DiCaprio MR, Enneking WF. Fibrous dysplasia. Pathophysiology, evaluation, and treatment. J Bone Joint Surg Am. 2005 Aug;87(8):1848-64. Review. PubMed PMID: 16085630. ](http://www.ncbi.nlm.nih.gov/pubmed/16085630)[View Abstract at](http://www.ncbi.nlm.nih.gov/pubmed/16085630)[ ](http://www.ncbi.nlm.nih.gov/pubmed/16085630)[PubMed](http://www.ncbi.nlm.nih.gov/pubmed/16085630)
40. [Chapurlat RD, Orcel P. Fibrous dysplasia of bone and McCune-Albright syndrome. Best Pract Res Clin Rheumatol. 2008 Mar;22(1):55-69. doi: 10.1016/j.berh.2007.11.004. Review. PubMed PMID: 18328981. ](http://www.ncbi.nlm.nih.gov/pubmed/18328981)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/18328981)
41. Ippolito E, Valentini MB, Lala R, De Maio F, Sorge R, Farsetti P. Changing Pattern of Femoral Deformity During Growth in Polyostotic Fibrous Dysplasia of the Bone: An Analysis of 46 Cases. J Pediatr Orthop. 2016 Jul-Aug;36(5):488-93. doi: 10.1097/BPO.0000000000000473. PubMed PMID:
[25887818/. ](http://www.ncbi.nlm.nih.gov/pubmed/25887818)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/25887818)
42. [Leet AI, Collins MT. Current approach to fibrous dysplasia of bone and McCune-Albright syndrome. J Child Orthop. 2007 Mar;1(1):3-17. doi: 10.1007/s11832-007-0006-8. Epub 2007 Feb 23. PubMed PMID: 19308500. ](http://www.ncbi.nlm.nih.gov/pubmed/19308500)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/19308500)

DISCUSSION: The patient has a periprosthetic fracture of the patella but is able to actively extend his knee. Despite the wide displacement of the fracture fragments, nonsurgical management is recommended given the high risk of complications and problems when open treatment of these fractures is undertaken.

REFERENCES: Ortiguera CJ, Berry DJ: Patellar fracture after total knee arthroplasty. J Bone Joint Surg Am 2002;84:532-540.
Parvizi J, Kim KI, Oliashirazi A, et al: Periprosthetic patella fractures. Clin Orthop Relat Res
2006;446:161-166.

Figure 43a Figure 43b

This pathology is most consistent with giant-cell tumor. Note the presence of multinucleated cells and stroma of spindlelike cells with pale staining cytoplasm and nuclei. Giant-cell tumors typically occur in patients ages 20 to 40. Common sites include the epiphysis of the distal femur or proximal tibia (50% of the time). Although it is a benign lesion, giant-cell tumors have a tendency for bone destruction, recurrence, and, rarely, metastasis. The initial treatment of choice is curettage with grafting or cementation. For recurrent or stage III tumors, wide excision may be necessary. Chemotherapy or radiation therapy are not indicated as initial treatment, especially if this is an isolated primary lesion.
RECOMMENDED READINGS
106. [Turcotte RE. Giant cell tumor of bone. Orthop Clin North Am. 2006 Jan;37(1):35-51. Review. PubMed PMID: 16311110.](http://www.ncbi.nlm.nih.gov/pubmed/16311110)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/16311110)
107. [Eckardt JJ, Grogan TJ. Giant cell tumor of bone. Clin Orthop Relat Res. 1986 Mar;(204):45-58. Review. PubMed PMID: 3514036.](http://www.ncbi.nlm.nih.gov/pubmed/3514036)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/3514036)

I. Important facts concerning FGFR3 physiology and disorders
A. Gain in function mutation results in achondroplasia
1/. Point mutation
2/. Homogenous (single, constant amino acid change)
3/. Receptor is active even without ligand binding
4/. Autosomal dominant
B. Regulates cell growth, proliferation, and differentiation
C . Ligand binding results in phosphorylation of the tyrosine kinase domain
D. Activation of the receptor limits enchondral ossification
E. Deficiency of the receptor results in elongation of the vertebral column and long bones (knockout mice) Correct Answe Gain of function mutation

The Coleman block test is used to demonstrate a flexible hindfoot. If the heel corrects from varus to neutral or slight valgus by bearing weight on a block supporting the lateral column of the foot, the subtalar joint remains flexible. This indicates that the varus position is secondary to the plantar flexed first ray or valgus position of the forefoot. Therefore, the most appropriate procedure is a dorsiflexion first metatarsal osteotomy. Arthrodesis is indicated in degenerative conditions. The peroneal brevis does not contribute to the cavus foot deformity. Medializing calcaneal osteotomy assists in correction of a flexible flatfoot.

- The anterolateral bundle is shorter, thicker, and stronger than the posteromedial bundle.

DISCUSSION: This question centers on the prophylactic treatment to reduce the risk of heterotopic bone formation. Prophylaxis is indicated because he has already demonstrated bone formation with his prior hip arthroplasty, which places him at increased risk for developing heterotopic bone on the contralateral side. He is on warfarin and has renal insufficiency, which makes the use of NSAIDs contraindicated. The recommended dose is 600 to 800 centigrey of radiation given within 24 hours of surgery preoperatively or 72 hours postoperatively.

REFERENCES: Kolbl O, Knelles D, Barthel T, et al: Preoperative irradiation versus the use of nonsteroidal anti-inflammatory drugs for prevention of heterotopic ossification following total hip replacement: The results of a randomized trial. Int J Radiat Oncol Biol Phys 1998;42:397-401.
Pakos EE, Ioannidis JP: Radiotherapy vs nonsteroidal anti-inflammatory drugs for the prevention of heterotopic ossification after major hip surgery: A meta-analysis of randomized trials. Int J Radiat Oncol Biol Phys 2004;60:888-895.
Seegenschmiedt MH, Makoski HB, Micke O, et al: Radiation prophylaxis for heterotopic ossification about the hip joint: A multicenter study. Int J Radiat Oncol Biol Phys 2001 ;51:756-765.

Figure 23 a Figure 23b

**
This is a prospective comparative study but is not randomized or blinded and
is therefore a Level II therapeutic study. To qualify as Level I, it would need to be a high- quality randomized trial with narrow confidence intervals regardless of a significant difference or no difference in outcomes. Level III would be
case-control studies or retrospective comparisons. Level IV is case series and Level V is expert opinion.

Several studies have shown that only patient age and pre-injury functional independence measure scores were independent predictors of functional outcome after hip fracture.
Hip fractures are common injuries and typically sustained from a standing level fall in the elderly. These fragility fractures can be a clinical sign of overall decline of the patient, and when coupled with poor pre-injury cognitive function and decreased mobility, mortality rates are increased as compared to
patients of the same age.
The Soderqvist et al study showed that a Short Portable Mental Status Questionnaire score of <3 and male gender were associated with an increased mortality rate during the first twelve months. Moreover, patients with a score of <3 had a significantly worse outcome with regard to the ability to walk and to perform the activities of daily living.
The referenced study by Holt et al is a prospective review of 1000 hip fractures and reported that pre-injury mobility to be the most significant determinant for post-operative survival.
The referenced study by Cornwall et al found that six-month mortality was lowest for patients with nondisplaced femoral neck fractures (5.7%) and highest for patients with displaced femoral neck fractures (15.8%), but multivariate analysis only identified preinjury function as an independent predictor of mortality.
Illustration A shows a displaced femoral neck fracture in an elderly patient. Incorrect Answers:
1,2,3,5: These injuries can be associated with elderly patients and are common
fragility fractures. However, no relationship between mortality and pre-injury cognitive function has been established at this point with any of these fractures.

DISCUSSION
There are two major arteries that supply the humeral head. One is the ascending branch of the anterior humeral circumflex artery, which runs up the lateral aspect of the bicipital groove terminating in the arcuate artery. The other is the posterior humeral circumflex artery, which more recently has been demonstrated to supply a significant portion of the blood supply to the humeral head. Capsular arteries also play a role in humeral head perfusion. Care should be taken to preserve all intact arterial supply when performing ORIF, as injury to these arteries may result in avascular necrosis. In general, the most common complications of locked plating include loss of reduction with penetration of the joint by the screws, particularly with initial varus positioning of the humeral head. Placement of the plate in the position described, however, should not have an impact on any of
the other complications noted.

The ilioinguinal approach provides improved visualization of the pelviCinner surface and anterior column and medial wall of the acetabulum. The patient is placed supine or in a lazy lateral decubitus position. The principle of this approach is to dissect closely along the inner wall of the pelvis and lift each muscular and neurovascular structure off of the bone. Three windows are present in this approach, each providing access to different structures. The first window allows access to the anterior sacroiliaCjoint, internal iliaCfossa, and upper anterior column

Though no gold standard exists, a reduction of concordant pain by at least 75 to 80% following an intra-articular, image-guided anesthetic injection is considered to be the most reliable method of identifying the SI joint as the cause of a patient's pain. Although provocation tests including the Gaenslen test, the compression test, thigh thrust, and Yeoman test are commonly used and can be helpful in diagnosing non-specific SI joint pain, individually they are not as reliable as the response to a diagnostic, anesthetic injection. Of note, the combination of all 4 manuevers has proven to be more useful than any one individual test. An MRI of the SI joint showing bony erosion and bone marrow edema suggests inflammatory arthritis and may not necessarily be associated with pain.
RECOMMENDED READINGS
Hancock MJ, Maher CG, Latimer J, Spindler MF, McAuley JH, Laslett M, Bogduk N. Systematic review of tests to identify the disc, SIJ or facet joint as the source of low back pain. Eur Spine
[J. 2007 Oct;16(10):1539-50. Epub 2007 Jun 14. PubMed PMID: 17566796. ](http://www.ncbi.nlm.nih.gov/pubmed/17566796)[View Abstract at](http://www.ncbi.nlm.nih.gov/pubmed/17566796)[ ](http://www.ncbi.nlm.nih.gov/pubmed/17566796)[PubMed](http://www.ncbi.nlm.nih.gov/pubmed/17566796)
Visser LH, Nijssen PG, Tijssen CC, van Middendorp JJ, Schieving J. Sciatica-like symptoms and the sacroiliac joint: clinical features and differential diagnosis. Eur Spine J. 2013 Jul;22(7):1657-64. doi: 10.1007/s00586-013-2660-5. Epub 2013 Mar 2. PubMed PMID:
[23455949/. ](http://www.ncbi.nlm.nih.gov/pubmed/23455949)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/23455949)
[Weber U, Zubler V, Pedersen SJ, Rufibach K, Lambert RG, Chan SM, Ostergaard M, Maksymowych WP. Development and validation of a magnetic resonance imaging reference criterion for defining a positive sacroiliac joint magnetic resonance imaging finding in spondyloarthritis. Arthritis Care Res (Hoboken). 2013 Jun;65(6):977-85. doi: 10.1002/acr.21893. PubMed PMID: 23203670. ](http://www.ncbi.nlm.nih.gov/pubmed/23203670)[View ](http://www.ncbi.nlm.nih.gov/pubmed/23203670)[Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/23203670)
CLINICAL SITUATION FOR QUESTION 72 THROUGH 75

Figures 72a through 72c are the sagittal CT scan and thoracic MR images of a 52-year-old woman with a history of pancreatic neuroendocrine tumor who has severe upper thoracic back pain despite receiving aggressive oral pain treatment. She has metastases in her liver, adrenal glands, and abdominal mesentery. The thoracic disease has been treated with conventional radiation. She continues to work her part-time job without experiencing signs or symptoms of myelopathy.
A B

C

All soft tissue sarcomas have the same signal sequence - low on T1 weighted images and high on T2 weighted images. | Tissue | T1 weighted | T2 weighted | |---|---|---| | Fat | High | Moderate | | Tendons | Low | Low | | Ligaments | Low | Low | | Fascial layers | Low | Low | | Cortical bone | Low | Low | | Muscle | Moderate | Moderate | | Normal marrow | High | Moderate | | Soft tissue sarcomas | Low | High | | Fluid (ganglions, effusions) | Low | High | | Pigmented villonodular synovitis* | Very low | Very low |

Results of treatment of subscapularis rupture are best when immediate repair is performed. When the cause of the anterior instability is the result of rupture of the subscapularis tendon and the component position is acceptable, revising the position of the component is unnecessary. Restoring the coracoacromial arch and subacromial decompression are related to superior instability and rotator cuff pathology, respectively, and would not correct the instability caused by subscapularis rupture.
REFERENCES: Moeckel BH, Altchek DW, Warren RF, Wickiewicz TL, Dines DM: Instability of the shoulder after arthroplasty. J Bone Joint Surg Am 1993;75:492-497.
Gerber C, Hersche O, Farron A: Isolated rupture of the subscapularis tendon. J Bone Joint Surg Am 1996;78:1015-1023.

A tarsal coalition is an abnormal connection of 2 or more bones in the foot. Although tarsal coalitions are present at birth, children and adults typically do not show signs of the disorder until early adolescence or later. The exact incidence of the disorder is hard to determine; however, it is caused by a gene mutation that affects cells that produce the tarsal bones. The 2 most common locations for tarsal coalitions are between the calcaneus and the navicular or between the talus and the calcaneus. It is estimated that 1 out of every 100 people may have a tarsal coalition. In 50% of cases, both feet are affected. Tarsal coalitions are rarely discovered until symptoms arise. Symptoms may include stiff and painful feet, a rigid flatfoot, or increased pain or a limp with high-level activities. Upon examination, symptoms may include tenderness in the area of the coalition, loss of motion, rigid flat feet, and arthritic changes of the joint. Imaging studies begin with radiographs. A CT scan can provide bony detail for imaging tarsal coalitions and determining the extent of the coalition and any accompanying degenerative change. MRI can provide details of the soft tissues. Treatment includes nonsurgical care including rest, orthotics, a temporary boot or cast, and injections. Surgical options include resection with interposition of muscle or fatty tissue from another area of the body or fusions when large (exceeding 50% of the joint), more severe coalitions are encountered.
RECOMMENDED READINGS
[Lemley F, Berlet G, Hill K, Philbin T, Isaac B, Lee T. Current concepts review: Tarsal coalition. Foot Ankle Int. 2006 Dec;27(12):1163-9. Review. PubMed PMID: 17207452. ](http://www.ncbi.nlm.nih.gov/pubmed/17207452)[View Abstract](http://www.ncbi.nlm.nih.gov/pubmed/17207452)[ ](http://www.ncbi.nlm.nih.gov/pubmed/17207452)[at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/17207452)
[Badgley CE. Coalition of the calcaneus and the navicular. Arch Surg. 1927;15:75-88. Conway JJ, Cowell HR. Tarsal coalition: clinical significance and roentgenographic demonstration. Radiology. 1969 Mar;92(4):799-811. PubMed PMID: 5767760. ](http://www.ncbi.nlm.nih.gov/pubmed/5767760)[View Abstract](http://www.ncbi.nlm.nih.gov/pubmed/5767760)[ ](http://www.ncbi.nlm.nih.gov/pubmed/5767760)[at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/5767760)
Herzenberg JE, Goldner JL, Martinez S, Silverman PM. Computerized tomography of talocalcaneal tarsal coalition: a clinical and anatomic study. Foot Ankle. 1986 Jun;6(6):273-
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[Wechsler RJ, Schweitzer ME, Deely DM, Horn BD, Pizzutillo PD. Tarsal coalition: depiction and characterization with CT and MR imaging. Radiology. 1994 Nov;193(2):447-52. PubMed PMID: 7972761. ](http://www.ncbi.nlm.nih.gov/pubmed/7972761)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/7972761)
[Leonard MA. The inheritance of tarsal coalition and its relationship to spastic flat foot. J Bone Joint Surg Br. 1974 Aug;56B(3):520-6. PubMed PMID: 4421359. ](http://www.ncbi.nlm.nih.gov/pubmed/4421359)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/4421359)

The patient has a bicondylar tibial plateau fracture extending to the diaphysis (Schatzker VI). Given his swelling and fracture blisters, the most appropriate next step would be knee-spanning external fixation.
High energy injuries of the tibia are often accompanied by significant soft tissue damage and swelling. Tibial plateau fractures, and more often pilon fractures, with significant swelling or fracture blisters are best managed acutely with external fixation to allow swelling to improve before definitive fixation. This strategy, which typically applies more often to pilon fractures, helps to limit infection and wound healing complications.
Reahl et al. retrospectively reviewed 419 patients who underwent surgical management of tibial plateau fractures to determine risk factors for subsequent surgery for knee stiffness. They found that amount of time spent in external fixation and bilateral tibial plateau fractures were independent risk factors for need for later surgery for knee stiffness.
Egol et al. investigated a staged treatment protocol for high energy tibial plateau fractures. Initial treatment was with knee-spanning external fixation followed by definitive fixation at an average of 15 days later. While wound complications were low (5%), they do cite a potential downside of increased knee stiffness.
Figures A-D are knee x-rays and CT scan showing a bicondylar tibial plateau fracture with significant comminution.
Incorrect Answers:
Answer 1,2: A long leg splint or bivalve cast will not help maintain length and is not the most appropriate next step. Acute casting of a high energy fracture is not recommended
Answer 4,5: The presence of fracture blisters and soft tissue swelling indicate that immediate ORIF is not the most appropriate next step.

The patient has a global loss of motion that has failed to improve with 6 months of nonsurgical treatment; because he has reached a plateau, further nonsurgical management will likely be ineffective. Revision in the form of an open release is indicated to lyse intra- and extra-articular adhesions; subscapularis lengthening may be done concurrently as needed. Revising to a smaller head can be considered if adequate motion is not achieved. The radiographs reveal an adequate neck cut with appropriate seating of the component. Removing the glenoid component will decrease capsular tension but will probably increase pain because of the lack of glenoid resurfacing. Increasing humeral retroversion will not improve motion.
REFERENCES: Cuomo F, Checroun A: Avoiding pitfalls and complication in total shoulder arthroplasty. Orthop Clin North Am 1998;29:507-518.
Wirth MA, Rockwood CA Jr: Complications of shoulder arthroplasty. Clin Orthop 1994;307:47-69.

Primary TKA with respect to Knee Society scores and operative complications shows that a primary TKA group scored 88% good to excellent results compared to 63% for the post-HTO group

Upon examination, this patient is exhibiting dislocation of the ECU tendon because of a disrupted sheath. He has failed nonsurgical measures, so surgery that would involve either direct repair or reconstruction of the tendon sheath is indicated. An option for reconstruction is to use a portion of the extensor retinaculum as a sheath substitute. Deepening of the ECU tendon groove at the distal ulna with direct repair of the sheath is another option, although a 2016 paper by Ghatan and associates did not find depth of the groove as a risk factor for subluxation. TFCC repair, lunotriquetral fusion, and DRUJ tenodesis are not appropriate because the examination clearly shows ECU tendon dislocation. TFCC and lunotriquetral ligament tears can occur along with ECU tendon dislocation, but no other examination findings suggest these conditions for this patient.
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4. [MacLennan AJ, Nemechek NM, Waitayawinyu T, Trumble TE. Diagnosis and anatomic reconstruction of extensor carpi ulnaris subluxation. J Hand Surg Am. 2008 Jan;33(1):59-64. doi: 10.1016/j.jhsa.2007.10.002. PubMed PMID: 18261666. ](http://www.ncbi.nlm.nih.gov/pubmed/18261666)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/18261666)
5. [Allende C, Le Viet D. Extensor carpi ulnaris problems at the wrist--classification, surgical treatment and results. J Hand Surg Br. 2005 Jun;30(3):265-72. Epub 2005 Apr 7.](http://www.ncbi.nlm.nih.gov/pubmed/15862366)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/15862366)
6. [Inoue G, Tamura Y. Surgical treatment for recurrent dislocation of the extensor carpi ulnaris tendon. J Hand Surg Br. 2001 Dec;26(6):556-9. PubMed PMID: 11884112. ](http://www.ncbi.nlm.nih.gov/pubmed/11884112)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/11884112)
7. [Ghatan AC, Puri SG, Morse KW, Hearns KA, von Althann C, Carlson MG. Relative Contribution of the Subsheath to Extensor Carpi Ulnaris Tendon Stability: Implications for Surgical Reconstruction and Rehabilitation. J Hand Surg Am. 2016 Feb;41(2):225-32. doi: 10.1016/j.jhsa.2015.10.024. Epub 2015 Dec 12. PubMed PMID: 26691954. ](http://www.ncbi.nlm.nih.gov/pubmed/26691954)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/26691954)

Rheumatoid arthritis commonly affects the metatarsophalangeal joints, which become destabilized with time resulting in hallux valgus and dislocated lesser claw toes. The result is metatarsalgia as the dislocated claw toes “pull” the fat pad distally. Severe hallux valgus reduces first ray load, which compounds the metatarsalgia because the load is transferred to the lesser metatarsal heads. First metatarsophalangeal arthrodesis restores weight bearing medially and corrects the painful bunion. Metatarsal head resection slackens the toe tendons to allow correction of the claw toes by whatever means necessary and decreases plantar load over the forefoot. Rheumatoid arthritis in the first metatarsophalangeal joint will continue to progress if osteotomies or a Lapidus procedure are performed. Keller resection arthroplasty increases transfer metatarsalgia and reduces push-off power during gait. Flexor-to-extensor tendon transfer of the lesser toes does not address the metatarsalgia and does not correct the dislocation of the metatarsophalangeal joint.
REFERENCES: Coughlin MJ: Arthritides, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, p 572.
Abdo RV, Iorio LJ: Rheumatoid arthritis of the foot and ankle. J Am Acad Orthop Surg 1994;2:326-332.

Crossover second toes are attributed to attenuation or rupture of the plantar plate and lateral collateral ligament and are associated with varying degrees of instability. Flexor-to-extensor transfer (Girdlestone/Taylor procedure) can provide intrinsic stability to the toe. Although plantar metatarsal head condylectomy can increase stability by resulting in scarring of the plantar plate, excision of the entire second metatarsal head carries a high risk of transfer metatarsalgia. Removal of the base of the proximal phalanx destabilizes the toe and should be reserved as a salvage procedure. Simple flexor tenotomy alone will not improve stability, and arthrodesis of the second metatarsophalangeal joint will limit motion and impair function.
REFERENCES: Coughlin MJ: Crossover second toe deformity. Foot Ankle 1987;8:29-39.
Thompson FM, Deland JT: Flexor tendon transfer for metatarsophalangeal instability of the second toe. Foot Ankle 1993;14:385-388.

Elderly patients with femoral neck fractures (FNF) undergoing total hip arthroplasty (THA) are less likely to require reoperation than those undergoing internal fixation.
Intracapsular FNF are common in elderly patients after a fall from standing height. Treatment depends on physiological age and displacement (Garden's classification). For displaced fractures, physiologically young patients are treated with internal fixation while physiologically old patients are treated with
either hemiarthroplasty (debilitated, less active patients) or THA (more active patients, those with acetabular disease or preexisting inflammatory arthritis).
Chammout et al. retrospectively compared the long term (17 years) results of THA (cemented both component) and ORIF (2 cannulated screws) in elderly patients (>65 years). They found no difference in mortality. But hip scores were higher and pain was better in the THA group, while reoperation rates were higher in the ORIF group. Walking speed was initially faster in the THA group, but later did not differ between groups. They recommend THA for elderly patients with displaced FNF.
Rogmark et al. prospectively compared closed reduction and internal fixation (CRIF) with arthroplasty (combining hemiarthroplasty and THA) at 2 years in elderly patients (>70 years). Failure rates were higher, pain was worse, and walking was more impaired after CRIF. They recommend arthroplasty for patients >70 with FNF.
Incorrect Answers:
Answer 1: Patients undergoing THA are more likely to have less pain than internal fixation.
Answer 3: Patients undergoing THA have superior functional outcome scores. Answer 4: Patients undergoing THA perform ADL better in the short term. In the long term, there is no difference in ADL between the groups.
Answer 5: Mortality rates are similar after the two procedures.

The patient has a cruciate-retaining (CR) prosthesis. The starting point for nail entry is more posterior than normal because of the femoral component. This leads to hyperextension at the fracture site.
Periprosthetic femur fractures above total knee implants occur in 2% of patients. It is important to note: (1) pre-injury function, to determine if the prosthesis was loose, (2) the type of implant (CR vs posterior stabilized, PS) as a PS implant with a closed box would make retrograde intramedullary nailing more difficult (the surgeon has to consider the size of the box vs size of the
nail, and if the box is smaller than the nail, must be prepared to enlarge the box with a metal-cutting burr, which has inherent problems of introducing wear debris into the joint), (3) pre-fracture radiographs help determine the position of the implants (flexion-extension, varus-valgus). These fractures can be treated with non-locking condylar buttress plates (not recommended today), fixed angle devices and intramedullary nailing.
McLaren et al. describe 7 osteopenic patients (mean age, 61yrs, range 47-84yrs) treated with retrograde supracondylar nailing. They suggest not reaming, and placing 2-3 screws in the distal fragment. This may require leaving the nail protruding by 1cm. They then suggest removing the protruding segment with a burr at the end of the procedure.
Haidukewych et al. debate plating vs nailing in a 80yr old osteopenic patient. It may be difficult to introduce retrograde intramedullary nails through the same incision if dense scar tissue is present. On the other hand, most plates require extensive dissection and do not respect the soft tissues and fracture biology, except for LISS plates and nails.
Figures A and B show a displaced Lewis and Rorabeck type II periprosthetic fracture. Illustration A shows the technique of retrograde supracondylar nailing. With the knee flexed, the fracture is reduced and the entry point is in the intercondylar notch. Illustration B shows a comparison between PS and CR implants. Note the "box" in the PS implant. This is absent in the CR implant.
Illustration C shows the Lewis and Rorabeck classification.
Incorrect Answers:
Answer 2: A formal arthrotomy is necessary to protect the polyethylene liner Answer 3: A CR implant does not possess a box, unlike posterior-stabilized (PS) implants. PS femoral components may require box enlargement with a burr if retrograde nailing is planned.
Answer 4: The backup plan should include plates which allow multiple points of fixation in the distal segment. These include locking periarticular plates and polyaxial locking plates, and non-locking condylar buttress plates. The DCS and ABP only have 1 (at most 2) point of fixation in the distal segment.
Answer 5: The backup plan should include devices that resist varus collapse (especially in cases with medial comminution), such as angle-stable devices (ABP, DCS and locking plates). Non-locking condylar buttress plates will not resist varus collapse.