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5. Sports Medicine MCQs

Practice Set 70 of 360

This practice set contains high-yield board review questions covering key concepts in 5. Sports Medicine. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 1381

Topic: 5. Sports Medicine

Which of the following findings is likely to be pathologic in a thin, well-conditioned endurance athlete?

. Left ventricular hypertrophy by voltage on electrocardiography (ECG)
. Primary AV block on ECG
. II/IV systolic murmur increased with standing and Valsalva maneuver
. Nonspecific STT wave changes in the lateral leads on ECG
. Resting sinus bradycardia at 40 beats per minute

Correct Answer & Explanation

. Left ventricular hypertrophy by voltage on electrocardiography (ECG)

Explanation

DISCUSSION: Left ventricular hypertrophy by voltage is a nonspecific diagnosis, especially in athletes with an asthenic body habitus.  High vagal tone in endurance athletes may result in first degree or even type I second degree (ie, Wenckebach) AV block in endurance athletes.  High vagal tone results in resting sinus bradycardia in many trained athletes.  A I-II/IV systolic ejection murmur is occasionally found in healthy athletes; however, when the murmur increases in intensity with maneuvers that decrease ventricular filling, such as standing or the Valsalva maneuver, dynamic obstruction that is the result of hypertrophic obstructive cardiomyopathy should be suspected.  Nonspecific STT wave changes in the lateral leads on ECG are not uncommon in highly trained athletes; thus, they are nonspecific for ischemic heart disease.REFERENCES: Pelliccia A, Maron BJ, Culasso F, DiPaolo FM, et al: Clinical significance of abnormal electrocardiographic patterns in trained athletes.  Circulation 2000;102:278-284.Maron BJ, Thompson PD, Puffer JC, McGrew CA: Cardiovascular preparticipation screening of competitive athletes: A statement for health professionals from the Sudden Death Committee (Clinical Cardiology) and Congenital Cardiac Defects Committee (Cardiovascular Disease in the Young), American Heart Association.  Circulation 1996;94:850-856.

Question 1382

Topic: Knee Sports

-What do the T2-weighted, fat-saturated MRI scans shown in Figures 76a through 76d reveal?

. Posterior cruciate ligament (PCL) tear, isolated
. PCL tear and medial meniscus tear
. Anterior cruciate ligament (ACL) tear, isolated
. ACL tear and medial meniscus tear

Correct Answer & Explanation

. Posterior cruciate ligament (PCL) tear, isolated

Explanation

DISCUSSION--The MRI scans show that edema is noted on the femoral insertion of the ACL consistent with a high-grade or complete ACL tear. The ACL is not visualized on the sagittal view, although the torn meniscus can be seen in the notch. On the coronal image, there is an empty lateral wall sign indicating proximal disruption of the ACL. The medial meniscus images show a disruption of normal meniscus morphology consistent with a bucket handle medial meniscus tear. Note the appearance on the sagittal MRI scan of what appears to be a second soft-tissue density in line with the PCL. This “double PCL” sign is highly indicative of a displaced medial meniscus tear rather than a displaced lateral meniscus tear.

Question 1383

Topic: Shoulder & Hip Sports

Figures 71a and 71b/ are the MR images of a 65-year-old man who dislocated his shoulder. What is his most likely chief symptom?

. Numbness in the anterior aspect of his shoulder
. Recurrent instability
. Difficulty raising his arm
. Biceps muscle deformity

Correct Answer & Explanation

. Numbness in the anterior aspect of his shoulder

Explanation

DISCUSSIONThis patient has a massive rotator cuff tear resulting in disruption of the transverse force couple between the subscapularis anteriorly and the infraspinatus and teres minor posteriorly. These muscles provide dynamic shoulder stability throughout active elevation. Loss of the force couple produces a pathologic increase in translation of the humeral head and decreased active abduction and external rotation, which results in difficulty raising an arm. The most common neurologic deficit after shoulder dislocation is isolated injury to the axillary nerve that supplies sensation to the lateral aspect of the shoulder, not the anterior aspect. Recurrent instability is uncommon unless there is a labral tear or massive subscapularis tear. The biceps muscle is not viewed in the MR images, and a complete proximal biceps tendon rupture would be uncommon in the setting of an anterior shoulder dislocation.CLINICAL SITUATION FOR QUESTIONS 72 THROUGH 75Figures 72a through 72e are the MR images of a 12-year-old boy with left lateral-sided knee pain following a football injury. He has a several-year history of recurrent knee pain that improves with rest. An examination reveals a moderate effusion. Range of motion is 0 degreesto 90 degrees and is limited by pain in deep flexion. He has tenderness to palpation along the lateral joint line, and no instability is noted.

Question 1384

Topic: 5. Sports Medicine

When performing a posterior cruciate ligament reconstruction with a tibial inlay-type approach, what is the approximate anatomic distance of the popliteal artery from the screws used for fixation of the bone block?

. 5 mm
. 10 mm
. 15 mm
. 20 mm
. 25 mm

Correct Answer & Explanation

. 5 mm

Explanation

DISCUSSION: Miller and associates reported the results of a cadaveric study of the vascular risk of a posterior approach for posterior cruciate ligament reconstruction using the tibial inlay technique.  The average distance from the screw to the popliteal artery was 21.1 mm(range, 18.1 mm to 31.7 mm).  Other approaches, such as the transtibial tunnel technique which involves drilling an anterior-posterior tunnel, have also been studied in cadavers.  Matava and associates noted that increasing flexion reduces but does not completely eliminate the risk of arterial injury during arthroscopic posterior cruciate ligament reconstruction.  However, this study did not use the small, medial utility incision recommended by Fanelli and associates, which creates an interval for the surgeon’s finger between the medial gastrocnemius and the posteromedial capsule so that any migration of the guidepin can be palpated and changed prior to any injury to the posterior neurovascular bundle.REFERENCES: Matava MJ, Sethi NS, Totty WG: Proximity of the posterior cruciate ligament insertion to the popliteal artery as a function of the knee flexion angle: Implications for posterior cruciate ligament reconstruction.  Arthroscopy 2000;16:796-804.Miller MD, Kline AJ, Gonzales J, et al: Vascular risk associated with posterior approach for posterior cruciate ligament reconstruction using the tibial inlay technique.  J Knee Surg 2002;15:137-140.Johnson DH, Fanelli GC, Miller MD: PCL 2002: Indications, double-bundle versus inlay technique and revision surgery.  Arthroscopy 2002;18:40-52.

Question 1385

Topic: 5. Sports Medicine

Which of the following physical examination findings is most likely present in the condition producing the MRI findings shown in Figure 92?

. Valgus laxity at 30 degrees of knee flexion
. Varus laxity at 30 degrees of knee flexion
. Posterior drawer
. Pivot shift
. Patellar apprehension

Correct Answer & Explanation

. Valgus laxity at 30 degrees of knee flexion

Explanation

DISCUSSION: The T2-weighted sagittal MRI scan shows the classic “bone bruise” pattern seen with an anterior cruciate ligament (ACL) tear. These lesions are thought to represent subcortical trabecular hemorrhages and are manifested as an increase in signal intensity on T2-weighted images and diminished signal intensity on Trweighted images. They are classically located in the mid-portion of the lateral femoral condyle and posterior aspect of the lateral tibial plateau. This is due to the fact that an ACL tear typically is the result of a valgus-extemal rotation of the femur on the fixed tibia. This places most of the weight-bearing stress on the lateral femoral condyle, which rotates laterally and impacts the posterior lip of the lateral tibial plateau. This may result in an impaction fracture if the force is great enough, but more frequently causes merely a microfracture of the involved subcortical trabeculae.REFERENCES: Vellet AP, Marks PH, Fowler PJ, et al: Occult posttraumatic osteochondral lesions of the knee: Prevalence, classification, and short-term sequelae evaluated with MR imaging. Radiology 1991;178:271-276.Cone R: Imaging sports-related injuries of the knee, in DeLee J, Drez D, Miller M (eds): DeLee & Drez’s Orthopaedic Sports Medicine: Principles and Practice, ed 2. Philadelphia, PA, WB Saunders, 2003, vol 2, pp 1595-1652.

Question 1386

Topic: Shoulder & Hip Sports

Which of the following is considered the cause of Milwaukee shoulder, a joint disease similar to rotator cuff arthropathy?

. Abundance of basic calcium phosphate crystals
. Abundance of calcium pyrophosphate crystals
. Gout
. Rheumatoid arthritis
. Osteonecrosis

Correct Answer & Explanation

. Abundance of basic calcium phosphate crystals

Explanation

DISCUSSION: Neer and associates focused on mechanical and nutritional factors as the etiology of rotator cuff arthropathy.  McCarty and associates, in describing a similar syndrome known as Milwaukee shoulder, focused on an inflammatory cause in proposing the pathogenic role of hydroxyapatite, a basic calcium phosphate.REFERENCES: Neer CS II, Craig EV, Fukuda H: Cuff-tear arthropathy.  J Bone Joint Surg Am 1983;65:1232-1244.McCarty DJ, Halverson PB, Carrera GF, Brewer BJ, Kozin F: Milwaukee shoulder: Association of microspheroids containing hydroxyapatite crystals, active collagenase, and neutral protease with rotator cuff defects. I: Clinical aspects. Arthritis Rheum 1981;24:464-473.

Question 1387

Topic: Shoulder & Hip Sports

A 72-year-old woman who fell on her right shoulder while using a treadmill is now unable to elevate her right arm. An MRI scan is shown in Figure 7. What is the most likely diagnosis?

. Axillary nerve injury
. Anterior dislocation
. Extension of a chronic large rotator cuff tear
. Suprascapular nerve entrapment from a ganglion cyst
. Greater tuberosity avulsion

Correct Answer & Explanation

. Axillary nerve injury

Explanation

DISCUSSION: The MRI scan reveals a large chronic rotator cuff tear with retraction and fatty infiltration atrophy of the supraspinatus and infraspinatus tendons.  This tear is responsible for the patient’s severe weakness and inability to elevate the arm.REFERENCE: Gerber C, Myer DC, Schneeberger AG, et al: Effect of tendon release and delayed repair on the structure of the muscles of the rotator cuff: An experimental study in sheep.  J Bone Joint Surg Am 2004;86:1973-1982.

Question 1388

Topic: 5. Sports Medicine

Figure 50 shows the MRI scan of a 20-year-old female college soccer player with knee pain. What is the most likely diagnosis?

. Normal knee
. Posterior cruciate ligament tear
. Quadriceps tendon rupture
. Proximal tibia fracture
. Femoral subchondral contusion

Correct Answer & Explanation

. Normal knee

Explanation

DISCUSSION: The MRI scan shows an acute complete tear of the posterior cruciate ligament.  No evidence is seen of a quadriceps tendon rupture, a tibia fracture, or a bone contusion.REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 533-557.Harner CD, Hoher J: Evaluation and treatment of posterior cruciate ligament injuries.  Am J Sports Med 1998;26:471-482.

Question 1389

Topic: 5. Sports Medicine

A 19-year-old college cross-country runner is amenorrheic and has recurrent stress fractures. Long-term management should consist of

. cross training with swimming and cycling.
. a complete cessation of running.
. vitamin D and calcium supplements.
. increased caloric intake.
. oral contraceptives, vitamin D, and calcium supplements.

Correct Answer & Explanation

. cross training with swimming and cycling.

Explanation

DISCUSSION: The triad of menstrual dysfunction, disordered eating, and stress fracture is well recognized in women who participate in endurance sports.  The best treatment remains to be determined, but at present, the combination of oral contraceptives to regulate menses, an increased intake of calcium and vitamin D, as well as nutritional counseling, is the recommended treatment for decreased bone mass related to exercise-induced amenorrhea.REFERENCES: Nattiv A, Armsey TD Jr: Stress injury to bone in the female athlete.  Clin Sports Med 1997;16:197-224.Drinkwater BL: Exercise and bones: Lessons learned from female athletes.  Am J Sports Med 1996;24:S33-S35.

Question 1390

Topic: 5. Sports Medicine

Figures 29a and 29b show the radiographs of a 13-year-old competitive gymnast who has had elbow pain for the past 2 weeks. The pain is worse with tumbling activities. Examination reveals a mild effusion and slight limitation of extension and forearm rotation with no locking. Initial management should consist of

. elbow arthroscopy.
. arthrotomy and internal fixation of the lesion.
. cessation of gymnastic activities.
. use of an elbow brace and continued gymnastic activities.
. open drilling of the lesion.

Correct Answer & Explanation

. elbow arthroscopy.

Explanation

DISCUSSION: The radiographs show a lesion in the capitellum that is consistent with osteochondritis dissecans.  There is no evidence of a loose body at this time.  Initial management should consist of cessation of gymnastic activities.  Nonsteroidal anti-inflammatory drugs and ice may help to alleviate acute symptoms; most symptoms usually resolve in 6 to 12 weeks.  The patient may then begin range-of-motion and strengthening exercises, with a slow return to activities once full range of motion and good strength have been achieved.  However, the prognosis for a return to high-level competitive gymnastics is guarded.  Surgery is indicated for intra-articular loose bodies, a locked elbow, or failure of nonsurgical management.  Surgery may be done either open or arthroscopically.  Loose bodies should be removed, and cartilage flaps should be debrided.  The results of bone grafting and internal fixation generally have been poor.  Drilling the base of the defect may stimulate replacement with fibrocartilage, but the benefits of this procedure are not well documented.REFERENCES: Maffulli N, Chan D, Aldridge MJ: Derangement of the articular surfaces of the elbow in young gymnasts.  J Pediatr Orthop 1992;12:344-350.Bauer M, Jonsson K, Josefsson PO, Linden B: Osteochondritis dissecans of the elbow: A long-term follow-up study.  Clin Orthop 1992;284:156-160.Tivnon MC, Anzel SH, Waugh TR: Surgical management of osteochondritis dissecans of the capitellum.  Am J Sports Med 1976;4:121-128.

Question 1391

Topic: 5. Sports Medicine

An 80-year-old man has had increasing shoulder pain for the past 4 months. He reports that it began with soreness and stiffness after chopping some wood. A coronal MRI scan is shown in Figure 16. Initial management should consist of

. shoulder exercises, mild analgesics, and activity modification.
. transfer of the latissimus dorsi to the greater tuberosity.
. arthroscopy and debridement of the tendon edges.
. arthroscopy, arthroscopic acromioplasty, coracoacromial ligament release, and mini open repair.
. arthroscopy, arthrotomy, acromioplasty, and primary repair of the rotator cuff.

Correct Answer & Explanation

. shoulder exercises, mild analgesics, and activity modification.

Explanation

DISCUSSION: The MRI scan shows a massive tear of the supraspinatus tendon with medial retraction to the level of the glenoid.  This is most likely an attritional tear with a high risk of failure of the repair.  The preferred treatment is nonsurgical management for pain and stiffness.  Acromioplasty and coracoacromial ligament release in this setting are controversial, as they can result in the devastating complication of anterosuperior subluxation of the humerus.REFERENCES: Rockwood CA Jr, Williams GR Jr, Burkhead WZ Jr: Debridement of degenerative, irreparable lesions of the rotator cuff.  J Bone Joint Surg Am 1995;77:857-866.Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 299-312.

Question 1392

Topic: Shoulder & Hip Sports

A 15-year-old wrestler sustains an abduction, hyperextension, and external rotation injury to his right shoulder. The MRI scan findings shown in Figures 27a and 27b are most consistent with Review Topic

. an avulsion of the lesser tuberosity.
. a midsubstance tear of the capsule.
. a tear of the anterior inferior labrum.
. a tear of the subscapularis.
. a tear of the humeral insertion of the inferior glenohumeral ligament.

Correct Answer & Explanation

. an avulsion of the lesser tuberosity.

Explanation

An isolated avulsion of the lesser tuberosity occurs very rarely and usually is found in 12- and 13-year-old adolescents. The MRI scans reveal a tear of the humeral attachment of the inferior glenohumeral ligament, a so-called HAGL lesion. This injury to the inferior glenohumeral ligament occurs much less commonly than the classic Bankart lesion (anterior inferior labral tear). A tear of the subscapularis occurs with a similar mechanism of injury but generally occurs in older individuals.

Question 1393

Topic: Shoulder & Hip Sports

A 20-year-old man reports painless snapping about the lateral aspect of the right hip. He denies any history of trauma. Examination reveals no limp or tenderness. Hip range of motion is full, and there is good strength. Radiographs are normal. What anatomic structure is most likely causing these symptoms?

. Acetabular labrum
. Iliopsoas
. Loose body
. Piriformis
. Iliotibial band

Correct Answer & Explanation

. Acetabular labrum

Explanation

DISCUSSION: Coxa saltans (snapping hip syndrome) can occur in two forms: external/lateral or interior/medial/anterior.  This patient has the external/lateral form.  The external/lateral form involves the iliotibial band, tensor fascia, or gluteus medius, which snaps over the greater trochanter.  The external form usually can be treated with physical therapy alone; however, several recent studies report satisfactory results with surgical treatment.  Faraj and associates reported good results from surgical Z-plasty in a series of 10 patients.  White and associates reported good results in a series of 16 patients with 17 hips who underwent surgical release of an external snapping hip.  The interior/medial/anterior form can involve the iliopsoas tendon, acetabular labrum, subluxation of the hip, and loose bodies.REFERENCES: White RA, Hughes MS, Burd T, et al: A new operative approach in the correction of external coxa saltans: The snapping hip.  Am J Sports Med 2004;32:1504-1508.Faraj AA, Moulton A, Sirivastava VM: Snapping iliotibial band: Report of ten cases and review of the literature.  Acta Orthop Belg 2001;67:19-23.Choi YS, Lee SM, Song BY, et al: Dynamic sonography of external snapping hip syndrome.J Ultrasound Med 2002;21:753-758.

Question 1394

Topic: Shoulder & Hip Sports

A 24-year-old avid volleyball player has noted gradual onset of shoulder fatigue and weakness limiting his game. Radiographs done by his primary care physician were normal and he has failed to improve with 6 weeks of physical therapy. Given the MRI image shown in Figure A, this patients physical exam may reveal weakness with which of the following actions? Review Topic

. Adduction
. Internal rotation
. Abduction and external rotation
. Abduction
. External rotation

Correct Answer & Explanation

. Adduction

Explanation

The MRI demonstrates of a ganglion cyst within the suprascapular notch, leading to atrophy of both the supraspinatus and infraspinatus. Thus, the patient would have weakness with both abduction and external rotation.Extrinsic compression or traction on the suprascapular nerve can result in suprascapular neuropathy. Compression of the nerve may occur at two distinct locations: the suprascapular notch and the spinoglenoid notch. Extrinsic compression of the suprascapular nerve by ganglion cysts can occur at the spinoglenoid notch or, less commonly, at the suprascapular notch. These cysts may originate from the transverse scapular ligament, the fibrous tissue of the scapula, or the glenohumeral joint.Mittal et al. reviewed the literature and found that the formation of ganglionic cysts in the spinoglenoid fossa occurs with cumulative trauma and leads to entrapment neuropathy of the suprascapular nerve and denervation of the infraspinatus muscle.Romeo et al. reported on various etiologies of suprascapular neuropathy including traction injury at the level of the transverse scapular ligament or the spinoglenoid ligament and direct trauma to the nerve. They noted that sports involving overhead motion, such as tennis, swimming, and weight lifting, may result in traction injury to the suprascapular nerve, leading to dysfunction. They also reported that the onset of weakness can be subtle and must be differentiated from cervical radiculopathy and degenerative disease of the shoulder.Figure A depicts a T2 coronal MRI of the shoulder with a cyst easily visualized occupying the suprascapular notch. Illustration A is an algorithm for the management of suprascapular neuropathy. Illustration B is a sagittal MRI from the same patient depicting the ganglion cyst within the suprascapular notch once again leading to atrophy of both the supraspinatus and infraspinatus (asterisks).Incorrect Answers:

Question 1395

Topic: Shoulder & Hip Sports

Which of the following is considered a reasonable goal for arthroplasty surgery in rotator cuff arthropathy?

. Restore normal humeral head glenoid contact location
. Restore full active overhead motion
. Restore proper glenoid version with bone preparation and use of a cemented glenoid component
. Achieve formal decompression and acromioplasty with resection of the coracoacromial ligament and distal clavicle
. Achieve a secure closure of the subscapularis with an appropriate head size

Correct Answer & Explanation

. Restore normal humeral head glenoid contact location

Explanation

DISCUSSION: 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.

Question 1396

Topic: 5. Sports Medicine

A young active patient with a complete isolated posterior cruciate ligament (PCL) tear undergoes a double bundle PCL reconstruction. The tensioning pattern of the anterolateral (AL) and posteromedial (PM) bundles most likely to reproduce the most normal knee kinematics would be to tension

. both bundles at 45 degrees of flexion.
. bundle AL at 45 degrees of flexion and bundle PM at 0 degrees of flexion.
. bundle AL at 45 degrees of flexion and bundle PM at 90 degrees of flexion.
. bundle AL at 90 degrees of flexion and bundle PM at 0 degrees of flexion.
. bundle AL at 90 degrees of flexion and bundle PM at 45 degrees of flexion.

Correct Answer & Explanation

. both bundles at 45 degrees of flexion.

Explanation

DISCUSSION: During flexion and extension of the normal knee, the AL bundle of the PCL is taut in flexion, and the PM bundle is taut when the knee is near extension.  The AL bundle is approximately two times larger at its midsubstance, stiffer, and has a higher ultimate load than the PM bundle.  In vitro testing has demonstrated that by tensioning the AL bundle at 90 degrees of flexion and the PM bundle at 0 degrees of flexion, essentially normal knee kinematics are restored.  Tensioning the AL bundle at 45 degrees of flexion and the PM bundle at 0 degrees of flexion would result in increased laxity with flexion at 90+ degrees.  Tensioning the AL bundle at 90 degrees of flexion and the PM bundle at 45 degrees of flexion would result in increased laxity near extension.REFERENCES: Harner CD, Janaushek MA, Kanamori A, Yagi M, Vogrin T, Woo SL: Biomechanical analysis of a double-bundle posterior cruciate ligament reconstruction.  Am J Sports Med 2000;28:144-151.Mannor DA, Shearn JT, Grood ES, Noyes FR, Levy MS: Two-bundle posterior cruciate ligament reconstruction: An in vitro analysis of graft placement and tension.  Am J Sports Med 2000;28:833-845.

Question 1397

Topic: Shoulder & Hip Sports

Figures 1 and 2 are the MR arthrogram images of a 16-year-old, right-hand-dominant baseball player who injured his left shoulder 4 weeks ago during a game. He now has pain, weakness, and the inability to swing a bat and can no longer do push-ups. He denies prior injury to his left shoulder. Radiographs are unremarkable. If present, what is the most likely complication after surgical treatment in this scenario?

. Recurrent instability
. Degenerative joint disease
. Shoulder stiffness
. Axillary nerve injury

Correct Answer & Explanation

. Recurrent instability

Explanation

Posterior shoulder instability is a rare form of instability that often presents with pain rather than feelings of instability. It often occurs in young athletes during activities that put the shoulder in an “at-risk position” (flexion, adduction, internal rotation). Repetitive microtrauma can lead to posterior shoulder instability such as seen in football linemen. Swinging a bat or golf club places the lead arm in a flexed, adducted, and internally rotated position, which can lead to posterior translation of the humeral head that is forcibly reduced in follow-through, as seen in this patient. The glenohumeral joint relies on static and dynamic stabilizers. Static stabilizers help prevent instability at the end ranges of motion when the ligaments are taut. Dynamic stabilizers work to prevent subluxation at midranges of motion, at which the ligaments are lax. The rotator cuff is integral as a dynamic stabilizer of the shoulder. It works through a process called concavity compression. The four muscles of the rotator cuff compress the humeral head into the concavity of the glenoid-labrum. This prevents the humeral head from subluxing during the midranges of motion. Of the four rotator cuff muscles, the subscapularis is most important at preventing posterior subluxation. This patient has posterior instability, and various surgical techniques may be indicated depending on findings. Arthroscopic labral repair is indicated for anterior instability. Arthroscopic posterior labral repair is indicated for this patient because he has a posterior labral tear and posterior instability. If a patient has ligamentous laxity (not seen in this scenario because sulcus and Beighton sign findings would be negative), a posterior capsular shift with rotator interval closure is indicated. If a patient has excessive glenoid retroversion (not seen in this scenario with 5 degrees of retroversion), a posterior opening-wedge osteotomy is appropriate. The most common complication seen after arthroscopic posterior labral repair is stiffness, followed by recurrent instabilityand         degenerative         joint         disease.

Question 1398

Topic: Shoulder & Hip Sports

Figure 53 shows the MRI scan of a 53-year-old carnival worker who has pain and swelling in the left shoulder as a result of attempting to stop a roller coaster car with his arm. Examination reveals decreased ROM, apprehension, and inability to move the dorsum of his hand away from his back. Treatment should consist of

. open acromioplasty
. open Bankart repair
. open subscapularis tendon repair
. inferior capsular shift
. a supervised physical therapy program

Correct Answer & Explanation

. open acromioplasty

Explanation

This patient has an acute tear of the subscapularis tendon both by MRI and physical exam. Treatment of choice is open repair. Nonoperative treatment is not indicated.

Question 1399

Topic: 5. Sports Medicine

An 18-year-old high school football player exits the field after making a tackle on the opening kickoff. He reports "feeling out of it" and states that he has a headache. He does not recall any loss of consciousness and has no amnesia. He is unable to list the months of the year in reverse order on questioning. He does not return to the game and feels normal at the completion of the game. What is the most sensitive test in assessing deficits after mild traumatic brain injury? Review Topic

. Head CT
. MRI of the head
. Neuropsychologic testing
. Radiographs of the skull
. Sideline assessment

Correct Answer & Explanation

. Head CT

Explanation

Most imaging studies in mild traumatic brain injury will be normal. Neuropsychologic testing is the most sensitive test in assessing mild deficits after traumatic brain injury. Sideline assessment is important but less sensitive in assessing deficits. The precise role of neuropsychologic testing in determining return to play has not been fully defined.

Question 1400

Topic: Shoulder & Hip Sports

What preoperative factor correlates best with the outcome of rotator cuff repair?

. Size of the tear
. Age of the patient
. Arm dominance
. Rupture of the long head of the biceps
. Preoperative pain score

Correct Answer & Explanation

. Size of the tear

Explanation

DISCUSSION: The size of the rotator cuff tear in both anteroposterior and mediolateral dimensions has been found to correlate best with outcome.  Older patient age and rupture of the long head of the biceps tend to be associated with larger tears and, therefore, may be associated indirectly with a poorer outcome.REFERENCES: Iannotti JP: Full-thickness rotator cuff tears: Factors affecting surgical outcome.  J Am Acad Orthop Surg 1994;2:87-95.Iannotti JP, Bernot MP, Kuhlman JR, Kelley MJ, Williams GR: Postoperative assessment of shoulder function: A prospective study of full-thickness rotator cuff tears.  J Shoulder Elbow Surg 1996;5:449-457.

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