Long-Term Outcomes of Arthroscopic Debridement With or Without Drilling for Osteochondritis Dissecans of the Capitellum in Adolescent Baseball Players: A ≥10-Year Follow-Up Study.

PURPOSE: To evaluate the long-term clinical outcomes of arthroscopic debridement for capitellar osteochondritis dissecans (OCD) in adolescent baseball players. METHODS: This retrospective study evaluated clinical outcomes of arthroscopic debridement for capitellar OCD in adolescent baseball players seen between 2003 and 2006. Inclusion criteria were at least 10 years of follow-up after surgery. Exclusion criteria were previous elbow surgery and age <12 years or >19 years. Patients were examined for presence of pain, inflammation (effusion), and range of motion. Outcome measures were determined using Timmerman/Andrews scores. Defect severity on preoperative radiographs was classified into 3 grades: small, moderate, and large. Return to baseball, pre- and postoperative range of motion and Timmerman/Andrews elbow score were evaluated according to defect severity. RESULTS: Twenty-three elbows of 23 baseball players (mean age, 14.7 [range, 13-17] years) underwent arthroscopic debridement for capitellar OCD. Mean follow-up duration was 11.5 (range, 10-13) years. Twenty patients (87%) returned to competitive baseball at their preoperative level; of these, 15 were non-pitchers and returned to the same position but only 1 of 5 pitchers returned to playing pitcher. One patient with a large defect and drilling underwent reoperation 11 years after the initial operation. Mean change in extension was 4.3° and that in flexion was 3.7°. Timmerman/Andrews score improved significantly from 160 (95% confidence interval 146.7-173.3) to 195 (95% confidence interval 185.2-204.8) at the most recent follow-up (P ˂ .0001). Osteochondral defects detected on preoperative radiographs were small in 10 patients, moderate in 7, and large in 6. There was no significant between-group difference in extension, flexion, or Timmerman/Andrews score preoperatively or at the most recent follow-up. CONCLUSIONS: Arthroscopic debridement with or without drilling allowed return to play in adolescent baseball players for positions other than pitchers. Long-term outcomes are likely durable regardless of lesion size. LEVEL OF EVIDENCE: Level IV, Case series.

Outcome of an elbow check-up system for child and adolescent baseball players.

PURPOSE: Our aim was to examine the outcome of an elbow check-up system for youth baseball players. In particular, we investigated the nature of elbow injuries in youth baseball players with elbow pain and ultrasonographic findings of the capitellum. MATERIALS AND METHODS: A total of 1605 players participating in the regional summer championship in July 2013 underwent a questionnaire survey, physical examination, ultrasound imaging, and radiographic examination. RESULTS: A total of 499 (31.1%) players reported episodes of elbow pain, of whom 320 (64.1%) had abnormal findings on physical examination, and 115 (35.9%) agreed to undergo radiography. Among them, 98 (85.2%) exhibited radiographic abnormalities. On the initial ultrasonography screening, 60 (3.7%) players had an abnormal finding and 55 (91.7%) agreed to undergo radiography. Among them, 26 (47.3%) were found to have osteochondritis dissecans (OCD) of the capitellum on radiographs. CONCLUSIONS: About 30% of youth baseball players had episodes of elbow pain, and 64.1% of players with elbow pain had abnormal findings on physical examination. Furthermore, 85.2% of subjects who underwent radiographic examination exhibited radiographic abnormalities. About 4% of young baseball players had an abnormal finding on initial ultrasonography screening, and nearly 50% of them had OCD of the capitellum on radiographs. J. Med. Invest. 63: 171-174, August, 2016.

Epidemiology of shoulder injuries in young baseball players and grading of radiologic findings of Little Leaguer's shoulder.

Relatively few epidemiological studies have examined shoulder injuries. This study aimed to investigate the epidemiology of such injuries in young baseball players. A total of 2,055 players aged 9-12 years who participated in a regional championship between 1983 and 1985 were the subjects of this investigation. They were assessed by questionnaire and radiographic examination. Prevalence of shoulder pain was determined according to position, years of baseball playing experience, and training hours per week. Radiographic examination was recommended to all players who complained of shoulder pain. Of the 2,055 subjects, 275 (13.4%) reported episodes of pain in the throwing shoulder. Years of baseball experience, but not player position or training hours per week, was significantly associated with shoulder pain. Forty-one of the 275 subjects reporting shoulder pain agreed to undergo radiography and 15 exhibited findings of Little Leaguer's shoulder. Their lesions could be classified into three distinct grades based on radiographic findings: grade I, widening of the epiphyseal plate in the lateral area (n=9); grade II, widening at all areas of the epiphyseal plate and demineralization of the metaphysis (n=5); and grade III, a slipped epiphysis (n=1). J. Med. Invest. 62: 123-125, August, 2015.

Radiographic follow-up study of Little Leaguer's shoulder.

OBJECTIVE: Little Leaguer's shoulder is a syndrome involving the proximal humeral epiphyseal plate. Conservative treatment usually resolves the symptoms. However, there are no reports of a radiographic follow-up study of this disease. The purpose of this study was to show the radiographic healing process of Little Leaguer's shoulder. MATERIALS AND METHODS: A total of 19 male baseball players diagnosed as having Little Leaguer's shoulder were retrospectively evaluated. The mean age at first presentation was 12.7 years. External rotation anteroposterior radiographs of the shoulder were taken. All patients were treated with rest from throwing, and no throwing was recommended until remodeling was confirmed. Follow-up radiographs were taken at 1-month intervals to assess healing. All patients were observed until healing was confirmed radiographically, after which they returned to baseball. The mean follow-up period was 8.5 months. In addition to radiography, patients were asked whether they had any symptoms and whether they had been able to return to baseball. RESULTS: At the first examination, radiographs showed a wider epiphyseal plate of the throwing side compared with the asymptomatic contralateral shoulder. Healing was observed in all cases. Healing occurred first along the medial side and was then extended laterally. The mean time required for healing was 4.7 months. All patients were able to return to playing baseball at their pre-injury level of play and were asymptomatic when examined at the final follow-up. CONCLUSION: The healing process of Little Leaguer's shoulder advanced from medial to lateral, and healing was achieved about 5 months after initial examination.

Elbow Injuries in Youth Baseball Players Without Prior Elbow Pain: A 1-Year Prospective Study.

BACKGROUND: Many risk factors for throwing injuries have been proposed. However, little is known about the risk factors for elbow injuries, particularly on physeal injuries in youth baseball players without prior elbow pain. PURPOSE: To investigate the risk factors for elbow injuries with a focus on physeal injuries that could predispose youth baseball players without elbow pain to elbow injuries. STUDY DESIGN: A prospective epidemiology study. METHODS: In 2006, 449 players without prior elbow pain were observed prospectively for 1 season to study injury incidence in relation to specific risk factors. The average age was 10.1 years (range, 7-11 years). One year later, all players were examined by administering a questionnaire, physical examination, and radiographic examination. Data for the groups with and without elbow pain were analyzed using multivariate logistic regression models. RESULTS: Among the 449 participants, 30.5% reported episodes of elbow pain during the season. Of the players who reported elbow pain, 72.3% presented abnormal findings on physical examination, and of those players, 81.4% had radiographic abnormalities. Multivariate analysis showed that the age of 12 years (at 1-year examination), pitcher and catcher positions, and playing more than 100 games per year were risk factors for elbow pain. CONCLUSION: It is expected that 30% of youth baseball players have elbow pain each year, and nearly 60% of players with elbow pain exhibit radiographic abnormalities. The age of 12 years, pitcher and catcher positions, and playing more than 100 games per year are risk factors for elbow pain.

The value of using radiographic criteria for the treatment of persistent symptomatic olecranon physis in adolescent throwing athletes.

BACKGROUND: Previously published reports present a variety of nonoperative and operative treatments for a persistent olecranon physis. However, the radiographic indication for the operative treatment is not clear. HYPOTHESIS: Our radiographic classification of persistent olecranon physis is helpful in formulating treatment decisions. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Sixteen male baseball players with persistent olecranon physis were retrospectively evaluated. The mean age at first presentation was 14.7 years (range, 12-17 years). The lesion was classified into 2 stages based on radiographic appearance. Stage I demonstrated widening of the olecranon epiphyseal plate when compared with the contralateral elbow on the lateral view. Sclerotic change indicated stage II. All patients underwent nonoperative treatment for at least 3 months. Follow-up radiographs were taken at 1-month intervals. Operative treatment was provided to the patients whose condition had failed to improve after nonoperative treatment. RESULTS: Of the 16 patients, 12 had stage I lesions and 4 had stage II lesions. Nonoperative management produced healing in 91.7% of patients with stage I lesions and none of the patients with stage II lesions. CONCLUSION: Our radiographic classification of persistent olecranon physis is useful for treatment decision making. In addition, our results demonstrated that sclerotic change is a high predictive indicator of the need for operative treatment.

Conservative treatment for osteochondrosis of the humeral capitellum.

BACKGROUND: Conservative treatment is recommended for the early stage of osteochondrosis of the humeral capitellum. However, the outcome of conservative treatment has not been well documented. HYPOTHESIS: Osteochondrosis of the humeral capitellum detected at an early stage responds well to conservative treatment. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: We retrospectively reviewed 176 patients with osteochondrosis of the humeral capitellum. There were 134 lesions that were stage I (radiolucent area) in patients with a mean age of 11.5 years and 42 lesions that were stage II (nondisplaced fragments) in patients with a mean age of 13.9 years based on anteroposterior radiographs of the elbow in 45 degrees of flexion. Conservative treatment was performed on 101 patients. The remaining 75 patients did not follow the authors' advice. Conservative treatment consisted of discontinuation of heavy use of the elbow for at least 6 months. Follow-up radiographs were taken at 1-month intervals. At a mean follow-up of 24 months, all patients were evaluated clinically and radiographically. RESULTS: Conservative management produced healing in 90.5% of stage I lesions and 52.9% of stage II lesions. The mean period required for healing was 14.9 months in stage I and 12.3 months in stage II. Sixty-six of 84 (78.6%) stage I patients and 9 of 17 (52.9%) stage II patients returned to competitive-level baseball. Of the 75 patients who did not follow our advice, healing was observed in 17 (22.7%). The healing rate was higher for the 101 patients who followed our advice as opposed to the 75 patients who did not. CONCLUSION: Osteochondrosis of the humeral capitellum can be successfully treated conservatively if treatment is begun in an early stage of the disease.

Why is the humeral retroversion of throwing athletes greater in dominant shoulders than in nondominant shoulders?

A rotation angle of the proximal humerus relative to the elbow (bicipital-forearm angle) was measured by use of ultrasonography to determine the relationship between humeral retroversion and growth in dominant and nondominant shoulders of 66 elementary and junior high school baseball players. The subjects were aged 12 years on average. The bicipital-forearm angle was significantly smaller in dominant shoulders than in nondominant shoulders. This indicated that the retroversion angle was greater in dominant shoulders than in nondominant shoulders. Furthermore, there was a moderately positive correlation between age and the bicipital-forearm angle in both dominant and nondominant shoulders. From these data, we conclude that the humeral retroversion angle decreases with age, and the decrease is much smaller in dominant shoulders. We assume that the repetitive throwing motion does not increase the retroversion of the humeral head but rather restricts the physiologic derotation process of the humeral head during growth.

Hamstring muscle function after tendon harvest for anterior cruciate ligament reconstruction: evaluation with T2 relaxation time of magnetic resonance imaging.

BACKGROUND: Regeneration of the semitendinosus and gracilis tendons after harvesting for anterior cruciate ligament reconstruction has been reported; however, muscle belly function after tendon regeneration has not been well documented. HYPOTHESIS: The semitendinosus and gracilis muscles are highly activated during knee flexion if their tendons are well regenerated after anterior cruciate ligament reconstruction. STUDY DESIGN: Descriptive laboratory study. METHODS: Hamstring muscle activation in 11 patients who had undergone anterior cruciate ligament reconstruction with semitendinosus and gracilis tendons was evaluated by measuring the increase of T2 relaxation time measured via magnetic resonance imaging after knee flexion exercise. Tendon regeneration was evaluated via magnetic resonance imaging. RESULTS: Both muscles increased T2 relaxation time after knee flexion exercise in the operated legs, and there was no significant difference in those values between the operated and nonoperated legs. All the semitendinosus tendons were regenerated at or below the joint line, but no gracilis tendons were observed beyond the joint line. The results indicated that both muscles were highly recruited during knee flexion, regardless of the degree of their tendon regeneration. CONCLUSION: The semitendinosus and gracilis muscles are able to restore or maintain their contractile capability after harvest of their tendons for anterior cruciate ligament reconstruction, regardless of the degree of regeneration.

The most effective exercise for strengthening the supraspinatus muscle: evaluation by magnetic resonance imaging.

BACKGROUND: Electromyography has been used to determine the best exercise for strengthening the supraspinatus muscle, but conflicting results have been reported. Magnetic resonance imaging T2 relaxation time appears to be more accurate in determining muscle activation. PURPOSE: To determine the best exercises for strengthening the supraspinatus muscle. STUDY DESIGN: Criterion standard. METHODS: Six male volunteers performed three exercises: the empty can, the full can, and horizontal abduction. Immediately before and after each exercise, magnetic resonance imaging examinations were performed and changes in relaxation time for the subscapularis, supraspinatus, infraspinatus, teres minor, and deltoid muscles were recorded. RESULTS: The supraspinatus muscle had the greatest change among the studied muscles in relaxation time for the empty can (10.5 ms) and full can (10.5 ms) exercises. After the horizontal abduction exercise the change in relaxation time for the supraspinatus muscle (3.6 ms) was significantly smaller than that for the posterior deltoid muscle (11.5 ms) and not significantly different from that of the other muscles studied. CONCLUSION: The empty can and full can exercises were most effective in activating the supraspinatus muscle.