Clinical and magnetic resonance imaging findings associated with Little League elbow.

BACKGROUND: Valgus overload in the skeletally immature elbow can lead to medial epicondyle apophysitis, or Little League elbow. The skeletal manifestations have been well described through radiographic studies. The involvement of surrounding structures, including the ulnar collateral ligament, remains unclear. The purpose of this study is to better characterize the involvement and relationship of medial elbow structures in Little League elbow through magnetic resonance (MR) imaging. METHODS: Institutional review board approval was obtained. Nine Little Leaguers, 8 to 13 years, with clinical diagnosis of Little League elbow were enrolled. Play history questionnaire (including age, position, pitching history, duration of symptoms, and Kerlan Jobe Orthopedic Clinic shoulder elbow score), clinical examination, radiograph, and MRI of both elbows were obtained for analysis. Evaluation of radiographs and MRIs were performed by 2 radiologists blinded to clinical findings. RESULTS: A majority of the players reported compliance with pitch count recommendations. Four out of 9 players, however, were throwing breaking pitches at an average age of 11 years. Radiographic abnormalities were present in 4 players. MRI abnormalities were present in 6 players. All patients demonstrated normal ulnar collateral ligament (UCL) on MRI. The distance from UCL origin to the medial epicondyle physis were measured in both injured and healthy elbows. No significant differences were found. This distance ranged from 0 to 4 mm. CONCLUSIONS: MRI of Little League elbow demonstrated more abnormalities compared with radiographs. The increased number of findings, however, does not change clinical management. MR evaluation of the ulnar collateral ligament demonstrates no role for reconstruction in Little League elbow. In addition, given the close proximity of the ligament to the physis, any surgical procedure involving the UCL origin should be performed with caution. LEVEL III: Diagnostic study.

Revision arthroscopic rotator cuff repair: repair integrity and clinical outcome.

BACKGROUND: Literature regarding the outcomes of revision rotator cuff repair is limited. The purposes of the present study were to report the tendon repair integrity and clinical outcomes for a cohort of patients following revision arthroscopic rotator cuff repair and to examine factors related to tendon healing and the influence of healing on clinical outcomes. METHODS: Twenty-one of twenty-nine consecutive revision arthroscopic rotator cuff repairs with a minimum of two years of postoperative follow-up were retrospectively reviewed. Outcomes were evaluated on the basis of a visual analog pain scale, the range of motion of the shoulder, the Simple Shoulder Test, the American Shoulder and Elbow Surgeons score, and the Constant score. Ultrasonography was used to examine repair integrity at a minimum of one year following surgery. Ten shoulders underwent arthroscopic repair of a recurrent single-tendon posterior rotator cuff tear, whereas eleven shoulders had repair of both the supraspinatus and infraspinatus. RESULTS: The mean age of the twenty-one subjects was 55.6 years; thirteen subjects were male and eight were female. Complete preoperative and postoperative clinical data were available for nineteen subjects after an average duration of follow-up of thirty-three months. Significant improvements were seen in terms of postoperative pain (p < 0.05), the Simple Shoulder Test score (p < 0.05), the American Shoulder and Elbow Surgeons function (p < 0.05) and total scores (p < 0.05), active forward elevation (p < 0.05), and active external rotation (p < 0.05). Postoperative ultrasound data were available for all twenty-one shoulders after a mean duration of follow-up of twenty-five months. Ten (48%) of the twenty-one shoulders had an intact repair. Seven (70%) of the ten single-tendon repairs were intact, compared with three (27%) of the eleven supraspinatus/infraspinatus repairs (p = 0.05). Patient age (p < 0.05) and the number of torn tendons (p = 0.05) had significant effects on postoperative tendon repair integrity. Shoulders with an intact repair had better postoperative Constant scores (p < 0.05) and scapular plane elevation strength (p < 0.05) in comparison with those with a recurrent tear. CONCLUSIONS: Revision arthroscopic rotator cuff repair results in reliable pain relief and improvement in shoulder function in selected cases. Approximately half of the revision repairs can be expected to be intact at a minimum of one year following surgery. Patient age and the number of torn tendons are related to postoperative tendon integrity. The postoperative integrity of the rotator cuff can have a significant influence on shoulder abduction strength and the Constant score.

Proximal humeral migration in shoulders with symptomatic and asymptomatic rotator cuff tears.

BACKGROUND: Proximal humeral migration is commonly seen in rotator-cuff-deficient shoulders. The specific effects of the size of the rotator cuff tear and of pain on glenohumeral kinematics have been poorly defined. The purpose of this study was to examine the influences of cuff tear size and pain, separately, on humeral migration in a series of patients with symptomatic and asymptomatic rotator cuff tears. METHODS: Ninety-eight asymptomatic and sixty-two symptomatic shoulders were identified from a cohort of patients with unilateral shoulder pain related to rotator cuff disease. All shoulders underwent ultrasonographic evaluation of the rotator cuff and standardized radiographic evaluation. Humeral migration was measured by three observers using software-enhanced radiographic analysis. RESULTS: There was no significant difference in rotator cuff tear size between the asymptomatic and symptomatic shoulders, although more tears involved the infraspinatus in the symptomatic group (p = 0.01). Proximal humeral migration was greater in the shoulders with a symptomatic tear than it was in those with an asymptomatic tear (p = 0.03). Tears that involved the infraspinatus resulted in more migration than did isolated supraspinatus tears in both the symptomatic (p = 0.01) and the asymptomatic shoulders (p = 0.03). When the symptomatic tears of > or =175 mm(2) were analyzed separately, the size of the tear was found to correlate strongly with humeral migration (p = 0.01). However, when the symptomatic tears that were <175 mm(2) were analyzed, neither tear size nor pain was found to have a significant relationship with migration. When the analysis was limited to full-thickness symptomatic tears of > or =175 mm(2), both pain (p = 0.002) and tear area (p = 0.0002) were found to have a significant effect on migration. Multivariate analysis showed that tear size (p = 0.01) was the strongest predictor of migration in symptomatic shoulders. CONCLUSIONS: Proximal humeral migration correlates with rotator cuff tear size. Tears extending into the infraspinatus tendon are associated with greater humeral migration than is seen with isolated supraspinatus tears. Humeral migration resulting from symptomatic rotator cuff tears is greater than that resulting from asymptomatic tears. Additionally, there is a critical size for tendon tears resulting in humeral migration in painful shoulders. Although both pain and tear size influence glenohumeral kinematics in symptomatic shoulders, only tear size is an independent predictor of humeral migration.

Effect of corticosteroids on the biomechanical strength of rat rotator cuff tendon.

BACKGROUND: The effect of corticosteroids on tendon properties is poorly understood, and current data are contradictory and diverse. The biomechanical effect of steroids on rotator cuff tendon has not been studied, to our knowledge. The current study was undertaken to characterize the biomechanical effects of corticosteroid exposure on both uninjured and injured rat rotator cuff tendon. METHODS: One hundred and twenty-three male Sprague-Dawley rats were randomly assigned to four groups: control (C), tendon injury (I), steroid exposure (S), and tendon injury plus steroid exposure (I+S). Unilateral tendon injuries consisting of a full-thickness defect across 50% of the total width of the infraspinatus tendon were created. Steroid treatment consisted of a single dose of methylprednisolone placed into the subacromial space. At one, three, and five weeks postoperatively, the shoulders were harvested and the infraspinatus tendon was subjected to biomechanical testing. Two specimens from each group were used for histological analysis. RESULTS: At one week, maximum load, maximum stress, and stiffness were all significantly decreased in Group S compared with the values in Group C. Mean maximum load decreased from 37.9 N in Group C to 27.5 N in Group S (p < 0.0005). Mean maximum stress decreased from 18.1 MPa in Group C to 13.6 MPa in Group S (p < 0.0005). Mean stiffness decreased from 26.3 N/mm in Group C to 17.8 N/mm in Group S (p < 0.0005). At one week, mean maximum stress in Group I+S (17.0 MPa) was significantly decreased compared with the value in Group I (19.5 MPa) (p < 0.0005). At both the three-week and the five-week time point, there were no significant differences between Group C and Group S or between Group I and Group I+S with regard to mean maximum load, maximum stress, or stiffness. Histological analysis showed fat cells and collagen attenuation in Groups S and I+S. These changes appeared to be transient. CONCLUSIONS: A single dose of corticosteroids significantly weakens both intact and injured rat rotator cuff tendons at one week. This effect is transient as the biomechanical properties of the steroid-exposed groups returned to control levels by three weeks.

The effect of corticosteroid on collagen expression in injured rotator cuff tendon.

BACKGROUND: Subacromial corticosteroid injections are commonly used in the nonoperative management of rotator cuff disease. The effects of corticosteroid injection on injured rotator cuff tendons have not been studied. Our aims were to characterize the acute response of rotator cuff tendons to injury through the analysis of the type-III to type-I collagen expression ratio, a tendon injury marker, and to examine the effects of corticosteroid on this response. METHODS: Sixty Sprague-Dawley rats were randomly assigned to four groups: control, tendon injury, steroid treatment, and tendon injury and steroid treatment. Six rats served as sham controls. Unilateral tendon injuries were created with full-thickness defects across 50% of the total width of the infraspinatus tendon, 5 mm from its humeral insertion. Steroid treatment with a single dose of methylprednisolone (0.6 mg/kg), equivalent to that given to humans, was injected into the subacromial space under direct visualization. Steroid treatment followed the creation of an injury in the rats in the injury and steroid treatment group. At one, three, and five weeks after the injury, the total RNA isolated from tendons was quantified with real-time polymerase chain reaction with use of primers for type-I and type-III collagen and ribosomal 18s RNA. RESULTS: The type-III to type-I collagen expression ratio remained at baseline at all time-points in the control and sham groups. At one week, the type-III to type-I collagen expression ratio increased more than fourfold above the control level in the tendon injury group (p = 0.017) and the tendon injury and steroid treatment group (p = 0.003). The ratio remained greater than twofold above the control at three weeks in both groups (p = 0.003 and p = 0.037) and returned to baseline at five weeks. Interestingly, the group that had steroid treatment only showed an increase of >4.5-fold (p = 0.001) in the type-III to type-I collagen expression ratio, without structural injury to the tendon. This ratio returned to baseline levels by three weeks. CONCLUSIONS: A single dose of corticosteroid does not alter the acute phase response of an injured rotator cuff tendon in the rat. However, the same steroid dose in uninjured tendons initiates a short-term response equivalent to that of structural injury.