Orthopedic Board Review MCQs: Arthroplasty, Sports Medicine & Trauma Part 223

The medial meniscus distributes force through the medial compartment. Peak loads in the affected compartment are increased by partial and complete meniscectomy. The posterior horn of the medial meniscus is also an important secondary restraint to anterior tibial translation in the ACL-deficient knee. In situ forces in the reconstructed ACL are increased with loss of the posterior horn of the medial meniscus.

The radiograph shows multiple wide physes, consistent with a diagnosis of rickets. A low serum phosphorous level and an elevated alkaline phosphatase level are the hallmarks in diagnosing familial hypophosphatemic Vitamin D-resistant rickets. Serum calcium is usually normal or low normal. This disease is inherited as an X-linked dominant trait and usually presents at age 18 to 24 months. The disease results from a poorly defined problem with renal phosphate transport in which normal dietary intake of vitamin D is insufficient to achieve normal bone mineralization. Renal tubular dysfunction is associated with urinary phosphate wasting. Treatment involves oral phosphate supplementation, which can cause hypocalcemia and secondary hyperparathyroidism. To prevent associated problems, high doses of Vitamin D are administered. While obtaining a scanogram may be clinically indicated in an associated limb-length discrepancy, and subsequent corrective surgery may be indicated, either of these choices would not be the first course of action. An orthosis may slow the progression of genu varum in this disorder but is less important than establishing the correct diagnosis to begin pharmacologic treatment. This amount of varum and tibial bowing far exceeds the normal limits of physiologic genu varum. Skeletal dysplasias usually are not associated with abnormal laboratory values.

Throwing athletes frequently develop medial collateral ligament sprain related to the repeated valgus stress that occurs on the medial elbow during the acceleration phase of throwing. This has the effect of not only causing pain, but also resulting in loss of velocity and distance during the throwing activity. The injury is generally well tolerated in most activities of daily living and only becomes problematic during the vigorous, stressful act of throwing. Absence of neurologic signs or symptoms makes ulnar nerve pathology unlikely. Pronator syndrome causes pain on the volar aspect of
the forearm during resisted forearm pronation and is not associated with the throwing motion in particular. Valgus extension overload may mimic medial collateral ligament injury, not varus extension injuries. Medial epicondylitis may be confused with ligament insufficiency but the examination and a history of pain only while throwing make this an unlikely diagnosis.

The MRI scans reveal a meso os acromiale with edema at the site in a skeletally mature patient.

A compartment syndrome of the deep posterior compartment causes symptoms related to structures running through that compartment. The deep posterior compartment includes the tibialis posterior, flexor hallucis longus, flexor digitorum longus, popliteus muscle, as well as the posterior tibial artery and the tibial nerve. Elevated pressures in this compartment would cause paresthesias in the distribution of the tibial nerve (plantar aspect of the foot) and would cause associated pain with passive stretch of the muscles in the compartment (great toe extension).

The patient has a postoperative stiff shoulder. The patient missed follow-up appointments and has not been participating in physical therapy for stretching. Based on normal radiographic findings, the shoulder is not dislocated; therefore, physical therapy should begin immediately. Continued sling immobilization will further worsen the stiffness. There is no indication of an infection or rotator cuff tear. Deep venous thrombosis would present with abnormal swelling and pain.

The treatment of low back pain ranges from nonsurgical management to surgical management. Whereas many other treatment modalities have been investigated, lumbar arthrodesis remains the primary surgical treatment of lumbar diskogenic pain. Outcomes of surgical management vary but are consistently impacted negatively by workers' compensation status. Neither the radiographic severity of disease, number of spinal segments, nor duration of disease has been correlated with clinical outcomes. While total disk arthroplasty was hoped to be an improvement over fusion, the evidence available to date has shown no significant differences over arthrodesis.

The late cocking and early acceleration phases are often combined when discussing medial stress on the elbow of the overhand thrower. This is when the greatest valgus moment across the medial elbow occurs and the forces reach the tensile limits of the medial ulnar collateral ligament.
Fleisig et al. were among the first to elucidate the elbow and shoulder kinetics in healthy adult pitchers using high-speed motion capture analysis. Inability to generate sufficient elbow varus torque may result in medial tension, lateral compression, or posteromedial impingement injury.
According to Lynch et al. the late cocking phase of the overhand throw places a marked valgus moment across the medial elbow. This repetitive force reaches the tensile limits of the medial collateral ligament, subjecting it to microtraumatic injury and attenuation. The anterior bundle of the medial collateral ligament has been identified as the primary restraint to valgus load and is the focus of reconstruction.
Incorrect Responses:
1,4,5: The medial elbow forces are less during these phases. 4: Ball release is not one of the 5 phases of throwing and marks the end of the acceleration and beginning of deceleration phase.

The suprascapular nerve is at risk of injury during anterior-superior anchor insertion for SLAP repair.
At the scapular spine level, the suprascapular nerve is approximately 1.5-2.0 cm from the glenoid cortex. This places the nerve at risk of injury during shoulder surgery, and injuries have been described. Arthroscopic SLAP repair is known to be a safe and relatively simple procedure. However, deep drilling or anchor insertion from the anterior or anteriosuperior portal during SLAP repair can place the suprascapular nerve at risk of iatrogenic injury.
Morgan et al. performed a cadaveric study to compare the risk of injury to the suprascapular nerve during suture anchor placement in the glenoid when using an anterosuperior portal versus a rotator interval portal. Standard 3 × 14 mm suture anchors were placed in the glenoid rim (1 o’clock, 11 o’clock, and 10 o’clock positions for the right shoulder). They showed that the distance from the far-posterior anchor tip to the suprascapular nerve averaged 8 mm (range, 3.4 to 14 mm) for the anterosuperior portal and 2.1 mm (range, 0 to 5.5 mm) for the rotator interval portal (P = .001).
Koh et al. evaluated the risk of suprascapular nerve injury during the drilling and anchor insertion for anterior SLAP repair. They inserted 1 suture anchor
arthroscopically from the anterior portal at 00:30-1:00 o’clock in right shoulders (11-11:30 in left). Using a mean drill depth was 14.2 (±2.8) mm, all suture anchors perforated the glenoid wall and the tips were measured to be approx. 3.1 (±2.7) mm from the suprascapular nerve.
Figure A shows an arthroscopic view and corresponding schematic image of arthroscopic drill position for SLAP repair. Illustration A shows the close proximity of anchor tip to the suprascapular nerve, as the nerve nerve enters the supraspinatus fossa below the superior transverse scapular ligament and then enters the infraspinatus fossa between the neck of the scapula and base of the spine of the scapula.
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(SBQ11UE.106) A 60 year-old diabetic man presents with increasing right shoulder pain and stiffness for 10 weeks. He works as a lawyer and has been treating the pain with non-steroidal anti-inflammatory drugs with little improvement. He had a previous injury to his right shoulder 15 years ago while playing hockey, but cannot recall any recent precipitants for this presentation. Physical examination shows significant reduction in right shoulder range of motion, with the greatest loss in external rotation. His MRI images are seen in Figures A-C. What would be the most appropriate treatment? Review Topic

Open supraspinatus cuff repair
Arthroscopic supraspinatus cuff repair
Reverse shoulder arthroplasty
Arthroscopic posterior capsular release
Physical therapy and medical management
The patient is presenting with right shoulder adhesive capsulitis. The most appropriate treatment at this time would be physical therapy and medical management (i.e., nonsteroidal anti-inflammatories +/- intra-articular steroid injections).
Adhesive capsulitis (aka frozen shoulder) is defined by pain and loss of both active and passive motion, especially loss of external rotation in comparison to the contralateral side. Risk factors include diabetes, thyroid disease, age, previous surgery and prolonged immobilization. Initial treatment options include NSAIDs, physical therapy, and intra-articular steroid injections. Surgical treatment is not commonly recommended, but may be used late in the course to address residual stiffness if extensive therapy has failed.
Griggs et al. prospectively reviewed seventy-five consecutive patients (seventy-seven shoulders) with adhesive capsulitis. They showed that 90 percent of the patients reported a satisfactory outcome with shoulder stretching exercises. However, male gender and diabetes mellitus were associated with worse motion at the final evaluation.
Hannafin et al. reviewed the treatment options for adhesive capsulitis. They suggest
that benign neglect, home-based and supervised physical therapy, and intra-articular corticosteroid injections should be considered in the early treatment of adhesive capsulitis. Duration of treatment should be considered for at least 3 months before more aggressive treatments are considered.
Levine et al. retrospectively reviewed the treatment and outcome of 234 patients with adhesive capsulitis. No significant difference was found for success of nonoperative treatment versus operative treatment or patient gender. With supervised treatment, most patients with adhesive capsulitis experience resolution with nonoperative measures in a relatively short period.
Figures A (Sagittal oblique T1 MRI), and Figure B (coronal oblique fat-saturated T2 MRI) show the anterior rotator cuff interval in the right shoulder demonstrate high-signal soft tissue thickening of the coracohumeral ligament (arrow). Figure C (Coronal oblique fat-saturated T2 MRI) demonstrates a thickened inferior glenohumeral ligament of the right shoulder.
Incorrect Answers:

Laminoplasty is one of the surgical options for decompressing the spinal cord in patients with cervical myelopathy. An ideal candidate is a patient with preserved cervical lordosis, as expansion of the canal relies on posterior drift of the spinal cord to achieve decompression. Posterior decompression, such as laminectomy and laminoplasty, are ideal for multilevel canal stenosis. Developed in Japan, laminoplasty is commonly performed in patients with OPLL as it avoids the dangers of working around the ossified posterior ligament. There is no age criterion for this procedure. As it is a motion-preserving procedure, 30 degrees of flexion-extension is not considered a contraindication.

The patient has a grade 2 open fracture and therefore needs wound debridement as a first step, followed by fracture stabilization preferably with an external fixator. A reamed intramedullary nail is not indicated in a 10-year-old child with open growth plates. Submuscular plating is not needed in an open fracture and there is no mention of fracture debridement. Percutaneous Kirschner wires will not provide adequate fracture stabilization, nor will a short leg cast. Flexible nailing should be considered as another form of fixation.

The MRI scans show an os acromiale of the mesoacromion type. This represents an unfused acromial apophysis. Pain is thought to be caused by either motion at the site or downward displacement of the anterior aspect of the acromion onto the rotator cuff, causing impingement. Most patients can be treated nonsurgically as they are usually asymptomatic. In those patients with persistent symptoms of pain and tenderness over the acromion, surgery consisting of rigid internal fixation and bone grafting has yielded satisfactory results. Excision may be a viable treatment option for the preacromion type.

Surgical indications for reverse total shoulder arthroplasty are expanding. In the setting of rotator cuff tear arthroplasty in which the native humeral head migrates superiorly, these implants impart several kinematic advantages. Implant center of rotation medial to the former joint surface improves glenoid component stability as the resultant force vector passes through the component throughout the arc of motion. A stable and fixed fulcrum for elevation is provided by matched radius of curvature between the glenoid and humeral components. A more distal center of rotation increases resting length and tone of the deltoid muscle, improving its effectiveness as a shoulder elevator. Medialized joint center of rotation increases the moment arm of the deltoid, requiring less muscle force to produce a given torque. This results in decreased articular shear stress.

The patient has arthrogryposis. Szoke and associates performed open reduction through a medial approach on 40 hip dislocations in 26 patients with this condition and reported good results in 80% and fair results in 12%. Due to the stiffness associated with this disorder, closed reduction with or without skin or skeletal traction is not feasible. Open reduction through an anterior approach is reserved for older children.

DISCUSSION:
MRI reveals an anterior labral tear, and the radiograph shows minimal arthritis with possible dysplasia. The  most  common  location  of  pain  in  patients  with  a  labral  tear  is  the  groin,  and  the  most  common physical finding is a positive impingement test result. Pain during sitting, clicking, and buttock pain are frequently described by patients with a labral tear, but these symptoms are less common than groin pain. A positive posterior impingement test finding is more common in patients with a posterior labral tear. Although age over 40 years and a body mass index higher than 30 can adversely affect clinical outcomes after joint preservation procedures such as PAO, hip arthroscopy, and femoral acetabular impingement surgery, the presence of hip arthritis on presurgical radiographs is the most commonly mentioned cause of failed hip joint preservation surgery. Tönnis grade is a radiographic measure of hip arthritis. A higher Outerbridge score is associated with more frequent poor outcomes after hip arthroscopy; however, the
Outerbridge cartilage score is determined by direct visualization at the time of surgery. The Outerbridge
score cannot be determined presurgically.

The medial ulnar collateral ligament is subjected to the greatest tensile stress during the late cocking/early acceleration phase of throwing.
The medial ulnar collateral ligament, or medial collateral ligament of the elbow, is composed of three bundles: an anterior bundle, a posterior bundle, and a variable transverse oblique bundle. During late cocking and early acceleration phases of the overhead throw, the medial UCL is subjected to the greatest amount of valgus stress to the elbow. During this phase, the forearm lags behind the upper arm and generates valgus stress while the elbow is primarily dependent on the anterior band of the UCL for stability. This puts the ligament at greatest risk of injury during this phase.
Fleisig et al. examined the kinetics of baseball pitching and the implications on injury mechanisms. They showed that the UCL contributes to 54% of the varus torque that is generated during the early acceleration of throwing. The position of greatest load occurred when the arm was flexed to 95 +/-14 degrees with an applied valgus load.
Illustration A shows a diagram of the medial ulnar collateral ligament ligament bundles.
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Ball and associates reported that "horseback riding was more dangerous than motorcycle riding." In a 10-year study of major traumatic injuries, they reported that 151 (2%) of 7,941 trauma patients had major equestrian injuries (injury severity score
> or = 12). Injuries included the chest (54%), head (48%), abdomen (22%), and extremities (17%). Only 9% of riders wore helmets, and 64% believed the accident was preventable. The authors noted that "helmet and vest use will be targeted in future injury prevention strategies." In another study, Frankel and associates noted that helmet use was only documented in 34% of riders. Although orthopaedic injuries are common, knee pads, wrist guards, boots, and quick release stirrups would most likely have less impact on injury prevention.

The corona mortis, or "crown of death," is a common anatomic variant that consists of an anastomosis between the obturator and the external iliac or inferior epigastric arteries or veins. Its reported incidence is over 80%. It is located behind the superior pubic ramus at a variable distance from the symphysis pubis (3 cm to 9 cm). It is at risk during surgical approaches to the anterior pelvic ring. If accidentally cut, the vessel can retract making control of hemorrhage difficult.