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Posterior superior impingement of the rotator cuff on the glenoid rim as a cause of shoulder pain in the overhead athlete
Arthroscopy: The Journal of Arthroscopic and Related Surgery 9(6):697--699
Published by Raven Press, Ltd. © 1993 Arthroscopy Association of North America
Case Report
Posterior Superior Impingement of the Rotator Cuff on the Glenoid Rim as a Cause of Shoulder Pain in the Overhead Athlete Stephen H. Liu, M.D. and Erin Boynton, M.D.
Summary: A case of impingement of the deep surface of the supraspinatus tendon on the posterior superior rim of the glenoid and mild anterior laxity has been presented. The partial-thickness tear of the undersurface rotator cuff tendon, degenerative tear of the posterior superior labrum, and osteochondral impression fracture of the humeral head have been documented. The purpose of this case report is to present the pathological findings associated with posterior superior glenoid rim impingement and emphasize its role as a cause of shoulder pain in the overhead athlete. In addition it is important to stress the fact that shoulder pain in the overhead athlete may be multifactorial. Key Words: Posterior superior glenoid impingement-- Undersurface--Rotator cuff tear--Overhead athlete.
The purpose of this case report is to analyze a patient with an undersurface rotator cuff tear secondary to posterior superior glenoid rim impingement and increased joint laxity and to emphasize the complex nature of shoulder pain in the overhead athlete.
Shoulder pain in the overhead athlete m a y be due to subacromial impingement (I), instability with secondary impingement (2), or excessive tension on the rotator cuff associated with repetitive activity (3). Recently, Walch et al. (4) described impingement of the deep surface of the supraspinatus tendon on the posterosuperior glenoid rim with the arm positioned in 90 ° of abduction and maximum external rotation as an additional cause of shoulder pain in the overhead athlete. The patients described by Walch et al. (4) complained primarily o f posterior shoulder pain with o v e r h e a d activity; n o n e had signs or s y m p t o m s c o n s i s t e n t with instability. Walch et al. (4) arthroscopicaUy d o c u m e n t e d partial-thickness tears of the supraspinatus/infraspinatus tendon, posterior superior labral lesions, and small osteochondral fractures of the humeral head.
CASE R E P O R T A 22-year-old right-hand-dominant collegiate tennis player presented with a 6-month history o f right shoulder pain. The pain was mainly posterior and aggravated only by serving and hitting an overhead smash while playing tennis. The pain was most severe with the arm in maximum external rotation at 90° of abduction. He denied any history of trauma or feelings of instability. Physical examination demonstrated no evidence of muscular atrophy, a full range of motion that was symmetrical except for 15 ° more external rotation with the arm in 90 ° o f abduction on the affected side. Strength and neurovascular examination were normal. Impingement signs were negative. The apprehension test was painful
From the Department of Orthopaedic Surgery, UCLA School of Medicine, Los Angeles, California. Address correspondence and reprint requests to Stephen H. Liu, M.D,, Department of Orthopaedic Surgery, UCLA School of Medicine, 10833 LeConte Avenue, Room.76-119 CHS, Los Angeles, CA 90024-6902, U.S.A.
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S. H. L I U A N D E. BO Y N T O N
but did not elicit feelings of instability. The relocation test was positive in that it relieved pain. Radiographs of the right shoulder were normal. The patient did not receive any cortisone injections. A trial of nonsteroidal antiinflammatory medication and physical therapy failed to allow the patient to play collegiate-level tennis. The patient elected to undergo shoulder arthroscopy. Examination with the patient under anesthesia demonstrated bilateral glenohumeral laxity, with 50% posterior subluxation bilaterally, 1-cm inferior sulcus bilaterally, and mildly increased anterior translation of the right shoulder compared with the left. Arthroscopic examination revealed an undersurface partial-thickness tear of the supraspinatus, Ellman (5) grade II, located just superior to the osteochondral indentation on the humeral head (Fig. 1). The location of the a small osteochondral impression fracture of the humeral head (Fig. 2) was in a more superior location than a Hills Sachs lesion. There was a normal bare area on the posterior humeral head. With abduction and external rotation at 90/90 ° , the area of the impression fracture was seen to impinge on the posterio r superior region of the glenoid. On further abduction (120 °) with maximum external rotation (110°), the area of the rotator cuff tear was seen to impinge on the posterior superior glenoid. There was a corresponding "kissing" lesion, represented by the indentation of the posterior labrum at the 11 o'clock position (Fig. 3). The posterior labrum tear was degenerative in nature and did n o t involve the biceps insertion. There was slight degeneration of the glenoid labrum in the region of the inferior glenohumeral ligament; how-
FIG. 1. Undersurface partial-thickness tear of the supraspinatus tendon. A: head; B: biceps tendon; C: undersurface rotator cuff tear; D: defect. Arthroscopy, Vol. 9, No. 6, 1993
FIG. 2. Osteochondral impression fracture of the humeral head near the insertion of the supraspinatus tendon. A: humeral head; B: defect; C: undersurface rotator cuff tear.
ever, no Bankart lesion was present. The long head of the biceps and subscapularis were normal. There were no loose bodies or synovitis. The patient underwent arthroscopic debridement of the posterior superior labral lesion and the rotator cuff. Aggressive physical therapy to address the anterior subluxation was begun immediately postoperatively. At early follow-up the patient is pain free and has returned to collegiate-level tennis. He is able to serve and volley overhead without pain. DISCUSSION Shoulder pain due to subacromial impingement (1), excessive traction on the rotator cuff (3), and impingement secondary to instability (2) are all accepted explanations for shoulder pain. A recent anatomic study by Jobe (6) showed the intraarticular
FIG. 3, Posterior, superior glenoid labrum lesion.
POSTERIOR S U P E R I O R GLENOID I M P I N G E M E N T
impingement of the supraspinatus on the posterior superior glenoid. This finding was confirmed arthroscopically by Walch et al. (4) in the overhead athletes, was not associated with increased laxity, and provides another explanation for shoulder pain in the overhead athlete. We believe that the cause of shoulder pain in the overhead athlete is complex and that the explanations above all contribute to the athlete's pain (2). Tremendous forces are applied to the soft tissues about the shoulder. Physiologic impingement of the rotator cuff on the posterior superior glenoid may become excessive with repetitive overhead activity (4,6,7). With repetitive activity, rotator cuff fiber overload, impingement, and failure occur. Excessive eccentric loading, combined with muscular fatigue, create a soft-tissue imbalance about the shoulder that may lead to increased glenohumeral translation. Increased glenohumeral translation produces abnormal stress in the static soft-tissue restraints of the shoulder with eventual stretching of the secondary stabilizers. In our case the patient showed signs and symptoms of both rotator cuff impingement and instability. On history and physical and arthroscopic examination, the rotator cuff impingement was thought to be the pre-
699
dominant factor causing this patient's pain. The follow-up of this patient is short and it remains to be seen whether the increased anterior translation that was detected by examination with the patient under anesthesia will be problematic in the future. Acknowledgment: We thank Raffy Mirzayan for his contribution to this publication. REFERENCES t. Hawkins RJ, Kennedy JC. Impingement syndrome in athletes. A m J Sports M e d 1980;8:151-8. 2. Jobe FW, Tibone JE, Jobe CM, Kvitne RS. The shoulder in sports. In: Rockwood CA, Matsen FA, eds. The shoulder, vol 2. Philadelphia: WB Saunders, 1990:961-90. 3. Andrews JR, Broussard TS, Carson WG. Arthroscopy of the shoulder in the management of partial tears of the rotator cuff: a preliminary report. Arthroscopy 1985 ;1:117-22. 4. Walch G, Boileau P, Noel E, Donell ST. Impingement of the deep surface of the supraspinatus tendon on the posterosuperior glenoid rim: an arthroscopic study. J Shoulder Elbow 1992; 1:238-45. 5. Ellman H. Diagnosis and treatment of incomplete rotator cuff tears. Clin Orthop 1990;254:64-80. 6. Jobe CM. Evidence for a superior glenoid impingement upon the rotator cuff. J Shoulder Elbow Surg 1993;2(part 2):S19. 7. Perry J. Anatomy and biomechanics of the shoulder in throwing, swimming, gymnastics and tennis. Clin Sports Med 1983;2:247-70.
Arthroscopy, Vol. 9, No. 6, 1993
Published by Raven Press, Ltd. © 1993 Arthroscopy Association of North America
Case Report
Posterior Superior Impingement of the Rotator Cuff on the Glenoid Rim as a Cause of Shoulder Pain in the Overhead Athlete Stephen H. Liu, M.D. and Erin Boynton, M.D.
Summary: A case of impingement of the deep surface of the supraspinatus tendon on the posterior superior rim of the glenoid and mild anterior laxity has been presented. The partial-thickness tear of the undersurface rotator cuff tendon, degenerative tear of the posterior superior labrum, and osteochondral impression fracture of the humeral head have been documented. The purpose of this case report is to present the pathological findings associated with posterior superior glenoid rim impingement and emphasize its role as a cause of shoulder pain in the overhead athlete. In addition it is important to stress the fact that shoulder pain in the overhead athlete may be multifactorial. Key Words: Posterior superior glenoid impingement-- Undersurface--Rotator cuff tear--Overhead athlete.
The purpose of this case report is to analyze a patient with an undersurface rotator cuff tear secondary to posterior superior glenoid rim impingement and increased joint laxity and to emphasize the complex nature of shoulder pain in the overhead athlete.
Shoulder pain in the overhead athlete m a y be due to subacromial impingement (I), instability with secondary impingement (2), or excessive tension on the rotator cuff associated with repetitive activity (3). Recently, Walch et al. (4) described impingement of the deep surface of the supraspinatus tendon on the posterosuperior glenoid rim with the arm positioned in 90 ° of abduction and maximum external rotation as an additional cause of shoulder pain in the overhead athlete. The patients described by Walch et al. (4) complained primarily o f posterior shoulder pain with o v e r h e a d activity; n o n e had signs or s y m p t o m s c o n s i s t e n t with instability. Walch et al. (4) arthroscopicaUy d o c u m e n t e d partial-thickness tears of the supraspinatus/infraspinatus tendon, posterior superior labral lesions, and small osteochondral fractures of the humeral head.
CASE R E P O R T A 22-year-old right-hand-dominant collegiate tennis player presented with a 6-month history o f right shoulder pain. The pain was mainly posterior and aggravated only by serving and hitting an overhead smash while playing tennis. The pain was most severe with the arm in maximum external rotation at 90° of abduction. He denied any history of trauma or feelings of instability. Physical examination demonstrated no evidence of muscular atrophy, a full range of motion that was symmetrical except for 15 ° more external rotation with the arm in 90 ° o f abduction on the affected side. Strength and neurovascular examination were normal. Impingement signs were negative. The apprehension test was painful
From the Department of Orthopaedic Surgery, UCLA School of Medicine, Los Angeles, California. Address correspondence and reprint requests to Stephen H. Liu, M.D,, Department of Orthopaedic Surgery, UCLA School of Medicine, 10833 LeConte Avenue, Room.76-119 CHS, Los Angeles, CA 90024-6902, U.S.A.
697
698
S. H. L I U A N D E. BO Y N T O N
but did not elicit feelings of instability. The relocation test was positive in that it relieved pain. Radiographs of the right shoulder were normal. The patient did not receive any cortisone injections. A trial of nonsteroidal antiinflammatory medication and physical therapy failed to allow the patient to play collegiate-level tennis. The patient elected to undergo shoulder arthroscopy. Examination with the patient under anesthesia demonstrated bilateral glenohumeral laxity, with 50% posterior subluxation bilaterally, 1-cm inferior sulcus bilaterally, and mildly increased anterior translation of the right shoulder compared with the left. Arthroscopic examination revealed an undersurface partial-thickness tear of the supraspinatus, Ellman (5) grade II, located just superior to the osteochondral indentation on the humeral head (Fig. 1). The location of the a small osteochondral impression fracture of the humeral head (Fig. 2) was in a more superior location than a Hills Sachs lesion. There was a normal bare area on the posterior humeral head. With abduction and external rotation at 90/90 ° , the area of the impression fracture was seen to impinge on the posterio r superior region of the glenoid. On further abduction (120 °) with maximum external rotation (110°), the area of the rotator cuff tear was seen to impinge on the posterior superior glenoid. There was a corresponding "kissing" lesion, represented by the indentation of the posterior labrum at the 11 o'clock position (Fig. 3). The posterior labrum tear was degenerative in nature and did n o t involve the biceps insertion. There was slight degeneration of the glenoid labrum in the region of the inferior glenohumeral ligament; how-
FIG. 1. Undersurface partial-thickness tear of the supraspinatus tendon. A: head; B: biceps tendon; C: undersurface rotator cuff tear; D: defect. Arthroscopy, Vol. 9, No. 6, 1993
FIG. 2. Osteochondral impression fracture of the humeral head near the insertion of the supraspinatus tendon. A: humeral head; B: defect; C: undersurface rotator cuff tear.
ever, no Bankart lesion was present. The long head of the biceps and subscapularis were normal. There were no loose bodies or synovitis. The patient underwent arthroscopic debridement of the posterior superior labral lesion and the rotator cuff. Aggressive physical therapy to address the anterior subluxation was begun immediately postoperatively. At early follow-up the patient is pain free and has returned to collegiate-level tennis. He is able to serve and volley overhead without pain. DISCUSSION Shoulder pain due to subacromial impingement (1), excessive traction on the rotator cuff (3), and impingement secondary to instability (2) are all accepted explanations for shoulder pain. A recent anatomic study by Jobe (6) showed the intraarticular
FIG. 3, Posterior, superior glenoid labrum lesion.
POSTERIOR S U P E R I O R GLENOID I M P I N G E M E N T
impingement of the supraspinatus on the posterior superior glenoid. This finding was confirmed arthroscopically by Walch et al. (4) in the overhead athletes, was not associated with increased laxity, and provides another explanation for shoulder pain in the overhead athlete. We believe that the cause of shoulder pain in the overhead athlete is complex and that the explanations above all contribute to the athlete's pain (2). Tremendous forces are applied to the soft tissues about the shoulder. Physiologic impingement of the rotator cuff on the posterior superior glenoid may become excessive with repetitive overhead activity (4,6,7). With repetitive activity, rotator cuff fiber overload, impingement, and failure occur. Excessive eccentric loading, combined with muscular fatigue, create a soft-tissue imbalance about the shoulder that may lead to increased glenohumeral translation. Increased glenohumeral translation produces abnormal stress in the static soft-tissue restraints of the shoulder with eventual stretching of the secondary stabilizers. In our case the patient showed signs and symptoms of both rotator cuff impingement and instability. On history and physical and arthroscopic examination, the rotator cuff impingement was thought to be the pre-
699
dominant factor causing this patient's pain. The follow-up of this patient is short and it remains to be seen whether the increased anterior translation that was detected by examination with the patient under anesthesia will be problematic in the future. Acknowledgment: We thank Raffy Mirzayan for his contribution to this publication. REFERENCES t. Hawkins RJ, Kennedy JC. Impingement syndrome in athletes. A m J Sports M e d 1980;8:151-8. 2. Jobe FW, Tibone JE, Jobe CM, Kvitne RS. The shoulder in sports. In: Rockwood CA, Matsen FA, eds. The shoulder, vol 2. Philadelphia: WB Saunders, 1990:961-90. 3. Andrews JR, Broussard TS, Carson WG. Arthroscopy of the shoulder in the management of partial tears of the rotator cuff: a preliminary report. Arthroscopy 1985 ;1:117-22. 4. Walch G, Boileau P, Noel E, Donell ST. Impingement of the deep surface of the supraspinatus tendon on the posterosuperior glenoid rim: an arthroscopic study. J Shoulder Elbow 1992; 1:238-45. 5. Ellman H. Diagnosis and treatment of incomplete rotator cuff tears. Clin Orthop 1990;254:64-80. 6. Jobe CM. Evidence for a superior glenoid impingement upon the rotator cuff. J Shoulder Elbow Surg 1993;2(part 2):S19. 7. Perry J. Anatomy and biomechanics of the shoulder in throwing, swimming, gymnastics and tennis. Clin Sports Med 1983;2:247-70.
Arthroscopy, Vol. 9, No. 6, 1993