Differences in Anatomic Adaptation and Injury Patterns Related to Valgus Extension Overload in Overhead Throwing Athletes

The purpose of our study was to determine differences in adaptative and injury patterns in the elbow related to valgus extension overload (VEO) in overhead throwing athletes by age. A total of 86 overhead throwing athletes and 23 controls underwent MRI or MR arthrography (MRA) of the elbow. Throwing athletes were divided by age into three groups: ≤16 years (26 subjects), 17-19 years (25 subjects), and ≥20 years (35 subjects). Consensus interpretation of each MRI was performed, with measurements of ulnar collateral ligament (UCL) thickness and subchondral sclerosis at the radial head, humeral trochlea, and olecranon process. A higher frequency of apophyseal and stress injuries was seen in adolescent athletes and increased incidence of soft tissue injuries was observed in older athletes. Early adaptive and degenerative changes were observed with high frequency independent of age. Significant differences were observed between athletes and controls for UCL thickness (p < 0.001) and subchondral sclerosis at the radial head (p < 0.001), humeral trochlea (p < 0.001), and olecranon process (p < 0.001). Significant differences based on athlete age were observed for UCL thickness (p < 0.001) and subchondral sclerosis at the olecranon process (p = 0.002). Our study highlights differences in anatomic adaptations related to VEO at the elbow between overhead throwing athletes and control subjects, as well as across age in throwing athletes.

Correlation of Joint Space Widening on Valgus Stress Magnetic Resonance Imaging With Level of Play and Innings Pitched in Professional Pitchers

Background

Previous studies have described various techniques and confirmed the clinical utility of valgus stress radiography and stress ultrasound in overhead athletes. The addition of valgus stress and a high-resolution anatomic assessment of the elbow with magnetic resonance imaging (MRI) in the active throwing position (flexed elbow valgus external rotation [FEVER] view) can add valuable diagnostic or prognostic information in throwing athletes.

Purpose/Hypothesis

The purpose of this study was to evaluate findings on MRI and subsequent performance in professional throwing athletes. It was hypothesized that joint space widening in the FEVER view would be predictive of performance and the risk of subsequent injuries.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

All pitchers on 2 Major League Baseball teams who consented to participate during their preseason screening in 2019 and 2020 underwent standard and FEVER MRI, and performance data from the following season were recorded, including injuries, mean throwing velocity, number of innings pitched, strikeout percentage, walk percentage, weighted on-base average, and level of play reached (not signed, minor league, or major league). Categorical variables were compared using the Fisher exact test or chi-square test, and continuous variables were compared using the Kruskal-Wallis test, as appropriate. Ordered logistic regression was used to determine the independent factors predicting performance.

Results

A total of 91 players underwent preseason imaging, and all players had subsequent performance data available. Multivariate analysis revealed that when controlling for age, mean velocity, history of injuries, presence of symptoms, and history of ulnar collateral ligament reconstruction, increased absolute joint space widening was predictive of a lower level of play (β = -0.63; P = .042). Univariate analysis demonstrated a significant correlation between relative joint space widening and level of play reached (β = -0.54; P = .034). Relative joint space widening remained a significant predictor of level of play (β = -0.87; P = .012) on multivariate analysis. Multivariate analysis also showed that both absolute joint space widening (β = -13.50; P = .012) and relative joint space widening (β = -13.60; P = .026) were predictive of the number of innings pitched in the subsequent season.

Conclusion

The present study demonstrates that findings on MRI with valgus stress correlated with the level of play reached and number of innings pitched in professional throwing athletes.

Return to play after ulnar collateral ligament reconstruction with concurrent posterior-compartment decompression

BACKGROUND

Medial ulnar collateral ligament (UCL) injuries and posterior elbow impingement commonly affect throwing athletes. Surgical intervention for each of these pathologies individually has been demonstrated to be successful with high return-to-play (RTP) rates. Our purpose was to report RTP rates for patients treated with concurrent UCL reconstruction (UCLR) and arthroscopic posterior débridement performed by the senior author.

MATERIALS AND METHODS

We retrospectively reviewed all elbow medial UCL procedures performed by the senior author from January 2016 through September 2020. The inclusion criteria included an elbow medial UCL operation with arthroscopic posterior-compartment débridement in a throwing athlete. The exclusion criteria included isolated UCLR surgery, non-primary surgery, and revision UCLR with either autograft or allograft. Using a chart review and publicly available information, we were able to determine patients' playing levels after their operations.

RESULTS

Twelve patients met the inclusion and exclusion criteria. The average age was 24.27 years (standard deviation, 4.92 years). Of the 12 patients, 10 returned to play at the same level (4 Major League Baseball players and 1 Triple A player) or at a higher level (2 players from Single A to Double A, 1 player from National Collegiate Athletic Association Division I to Single A, 1 player from rookie league to Single A, and 1 player from high school to National Collegiate Athletic Association Division I), 1 did not return to play, and 1 returned to play at a lower level, with an average RTP time of 14.64 months (standard deviation, 2.64 months). Of the 12 patients, 11 were pitchers; of these 11 pitchers, 9 had statistics available both before and after UCLR. Before UCLR, the average statistics for the pitchers were as follows: earned run average, 4.11 ± 0.85; walks and hits per inning pitched, 1.42 ± 0.26; strikeout-to-walk ratio, 3.00 ± 1.83; strikeouts per 9 innings, 8.80 ± 1.14; and innings pitched, 234.88 ± 316.74. After UCLR, their average statistics were as follows: earned run average, 5.24 ± 2.18 (P = .189); walks and hits per inning pitched, 1.55 ± 0.34 (P = .379); strikeout-to-walk ratio, 2.15 ± 0.98 (P = .263); strikeouts per 9 innings, 9.67 ± 1.91 (P = .293); and innings pitched, 138.71 ± 162.97 (P = .487).

DISCUSSION AND CONCLUSION

Although surgical intervention to address both posterior impingement and UCL injury is relatively rare (comprising 8.5% of all the senior author's UCLR procedures), our experience demonstrates that primary UCLR with concurrent arthroscopic posterior decompression is a reliable, safe, and successful surgical treatment for patients with UCL injury and posterior impingement and our results show no significant difference in statistical performance in pitchers before surgery vs. after surgery.

Reliability of an Observational Biomechanical Analysis Tool in Adolescent Baseball Pitchers

BACKGROUND

Improper pitching mechanics are a risk factor for arm injuries. While 3-dimensional (3D) motion analysis remains the gold standard for evaluation, most pitchers and clinicians do not have access to this costly technology. Recent advances in 2-dimensional (2D) video technology provide acceptable resolution for clinical analysis. However, no systematic assessment tools for pitching analysis exist.

PURPOSE

To determine the reliability of the Assessment of biomeChanical Efficiency System (ACES) screening tool using 2D video analysis to identify common biomechanical errors in adolescent pitchers.

STUDY DESIGN

Cross-sectional.

METHODS

Adolescent baseball pitchers underwent analysis using 2D video in indoor settings. Observational mechanics were collected using a 20-item scoring tool (ACES) based on 2D video analysis. Fleiss' kappa, interclass correlation coefficients (ICC), and frequencies were used to examine intra-/interrater reliability based on common pitching errors.

RESULTS

Twenty asymptomatic pitchers ages 12-18 years were included. Total ACES scores ranged from 1 to 13, normally distributed. ACES total score demonstrated excellent intra-rater reliability within each rater (ICC for rater 1 = 0.99 (95% CI; 0.98, 0.99); ICC for rater 2 = 0.94; 95% CI: 0.84, 0.97); ICC for rater 3 = 0.98 (95% CI: 0.96, 0.99)). There was excellent interrater reliability across the trials and raters (ICC = 0.91; 95% CI: 0.82, 0.96). The ACES tool demonstrated acceptable kappas for individual items and strong ICC 0.91 (95% CI: 0.82, 0.96) for total scores across the trials. Regarding identification of biomechanical errors, "front side position" was rated erroneous in 84/120 ratings (70%), stride length in 52/120 ratings (43.3%) and lead hip position in 53/120 ratings (44.2%).

CONCLUSIONS

The 20-item ACES scoring tool with 2D video analysis demonstrated excellent intra- and interrater reliability when utilized by raters of different musculoskeletal disciplines. Future studies validating 2D vs. 3D methodology are warranted before ACES is widely disseminated and utilized for adolescent pitchers. ACES is a practical and reliable clinical assessment tool utilizing 2D video analysis for coaches, instructors, and sports medicine providers to screen adolescent pitchers for common biomechanical errors.

LEVEL OF EVIDENCE

3b.

Surgical Management of Superior Labral Tears in Athletes: Focus on Biceps Tenodesis

Superior labrum anterior-posterior (SLAP) lesions are common in overhead athletes. Though some patients have asymptomatic lesions, many tears cause pain and diminished athletic performance. Accurate diagnosis of SLAP lesions can be challenging as the sensitivity and specificity of both the physical exam and advanced imaging is questionable. Management is also difficult, as treatment can be life-altering or career-ending for many athletes. If first-line nonoperative treatment fails, surgical options may be considered. The optimal surgical management of SLAP lesions in athletes is debated. Historically, return to play (RTP) rates among athletes who have undergone arthroscopic SLAP repair have been unsatisfactory, prompting clinicians to seek alternate surgical options. Biceps tenodesis (BT) has been postulated to eliminate biceps tendon-related pain in the shoulder and is increasingly used as a primary procedure for SLAP lesions. The purpose of this text is to review the current literature on the surgical management of SLAP lesions in athletes with an emphasis on the role of BT.

Ulnar Collateral Ligament Reconstruction in Adolescents: A Systematic Review

BACKGROUND

Ulnar collateral ligament (UCL) reconstruction is an established surgical technique to restore UCL deficiency, especially in the overhead throwing athlete. Over the past decade, the number of patients requiring UCL reconstruction has increased significantly, particularly in the adolescent patient population. Return-to-play rates after UCL reconstruction reported in the literature have ranged from 33% to 92%, and a recent systematic review noted a return-to-play rate of 89.40% in all high school athletes.

PURPOSE

To evaluate the outcomes, particularly return-to-play rates and subjective outcome scores, of UCL reconstruction of the elbow in adolescent throwing athletes.

STUDY DESIGN

Systematic review.

METHODS

A systematic review of the literature was conducted via the electronic databases Embase, PubMed, and Cochrane. Studies that reported on outcomes, particularly return-to-play rates, in adolescent throwing athletes met the inclusion criteria and were included in our analysis. Studies that did not report on adolescent throwing athletes and studies that reported on adolescent throwing athletes but did not specify the return-to-play outcomes for these athletes were excluded from our analysis.

RESULTS

Nine studies met the inclusion criteria and were included in this review. There were 404 baseball players and 10 javelin throwers included in our analysis. A total of 349 of the 414 patients (84.30%) were successfully able to return to play at the same level of competition or higher. Successful rates of return to prior performance ranged from 66.67% to 91.49% in our analysis. Javelin throwers had a mean 80.00% rate of return to prior performance, while baseball players had a mean return-to-play rate of 84.40%. Complications were evaluated for 8 (88.9%) studies and 283 (68.4%) patients. There were 11 (3.9%) reported complications and 5 (1.8%) reoperations.

CONCLUSION

The findings of this systematic review revealed that adolescent patients are generally able to return to their preinjury level of performance or higher with limited complications. Further investigation is necessary to determine long-term outcomes for return to play after UCL reconstruction of the elbow in adolescent throwing athletes.

Return to play rates after ulnar nerve transposition and decompression surgery: a retrospective analysis

Background

Medial elbow pain is a common complaint in overhead throwing athletes. The throwing motion places repetitive tensile and compressive forces on the elbow resulting in significant stress across the ulnohumeral joint. This stress can result in soft-tissue, ligamentous, and ulnar nerve injury. The purpose of this study was to retrospectively investigate the clinical findings and outcomes, including return to play rates, of patients who underwent ulnar nerve transposition surgery for isolated ulnar neuritis.

Methods

Throwing athletes who underwent isolated, primary ulnar nerve transposition surgery over an eight-year period, 2009 to 2017, were identified and included in our analysis. Nonthrowing athletes, those who underwent revision ulnar nerve transposition surgery, and those who underwent concomitant ulnar collateral ligament reconstruction or repair were excluded. Patients were contacted to complete the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow Score as well as a return to play rate questionnaire. The minimum follow-up was 2 years.

Results

Fifteen patients met the inclusion criteria: 13 (86.7%) men and 2 (13.3%) women. The average age at the time of surgery was 19.2 years old (range, 15.6-28.0). Preoperatively, 13 (86.7%) patients played baseball and 2 (13.3%) patients played softball. Two patients (13.3%) underwent a previous ulnar collateral ligament reconstruction. There were no complications. The average final follow-up was 65.26 (range, 24.44-113.29) months with an average Kerlan-Jobe Orthopaedic Clinic Score of 64.51 (range, 28.60-100.00). Thirteen (86.7%) patients were able to return to their preinjury sport, 2 to a higher level of competition, 8 to the same level, and 3 to a lower level. Seven of the 13 (53.8%) patients sustained a postoperative ipsilateral shoulder or elbow injury at an average of 19.57 (range, 7.00-36.00) months postoperatively. All patients reported sustaining the injury as a result of throwing.

Conclusion

The results of our study indicate that ulnar nerve transposition surgery in throwing athletes allows athletes to return to throwing with low reoperation rates. However, more than half of the athletes in our analysis sustained a subsequent ipsilateral shoulder or elbow injury. Further investigation regarding outcomes in throwing athletes after ulnar nerve transposition surgery is warranted.

The influence of lumbopelvic control on shoulder and elbow kinetics in elite baseball pitchers

BACKGROUND

Research has shown that diminished lumbopelvic control has a negative effect on pitching performance and can lead to more days on the disabled list. Despite the identified correlation between lumbopelvic control and injury, there is no research that has shown whether insufficient lumbopelvic control increases the force placed on the throwing arm.

METHODS

Forty-three asymptomatic, National Collegiate Athletic Association Division I and professional minor league baseball pitchers participated. We measured the bilateral amount of anterior-posterior lumbopelvic tilt during a single-leg stance trunk stability test. We measured the shoulder and elbow kinetics of the throwing arm during the pitching motion using a 3-dimensional, high-speed video capture system. We used 2-tailed Pearson product-moment correlation coefficients (r) to determine the strength of the relationships between variables (P < .05).

RESULTS

There were no significant relationships between the stride leg and any of the pitching kinetic variables (r < 0.23, P > .14). Similarly, there were no significant relationships between the drive leg and maximum shoulder distraction force, shoulder external rotation torque, or elbow distraction force (r <-0.24, P > .13). However, the drive leg did have significant relationships with both maximum shoulder horizontal torque (r = 0.44, P = .003) and elbow valgus torque (r = 0.46, P = .002).

CONCLUSIONS

Our results show that a relationship exists between lumbopelvic control of the drive leg and both shoulder horizontal torque and elbow valgus torque during the throwing motion. Because of these relationships, clinicians should consider incorporating lumbopelvic control training exercises to minimize the kinetic force placed on the throwing shoulder and elbow during the pitching motion.

Stress Fractures of the Elbow in the Throwing Athlete: A Systematic Review

Background:

Stress fractures of the elbow are rare in throwing athletes and present a challenge from both a management and rehabilitation perspective. Although the incidence of stress fractures of the elbow is increasing, there is a lack of data in the literature focused on throwers.

Purpose:

To evaluate studies regarding the management and outcomes of stress fractures of the elbow in throwing athletes.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review was conducted by searching the Scopus, PubMed, and Cochrane Library electronic databases to identify studies reporting on the management and outcomes of stress fractures in overhead-throwing athletes. Management data included nonoperative and operative modalities, and outcome data included return to play, encompassing the timing and level of activity. Studies were excluded if the stress fracture of the elbow was not a result of a sport injury attributed to throwing or if the study failed to report whether an athlete returned to play.

Results:

Fourteen studies met the inclusion criteria and were included in this analysis. There were 52 patients in total (50 male, 2 female) with a mean age of 19.7 years (range, 13-29.1 years). The olecranon was the most common location of the stress fracture (51 patients; 98.1%), followed by the distal humerus (1 patient; 1.9%). The majority of patients (n = 40; 76.9%) were treated operatively. Of the 40 patients who were treated surgically, 14 (35.0%) underwent a period of conservative treatment preoperatively that ultimately failed because of persistent nonunion or continued elbow pain. A total of 50 patients (96.2%) returned to sport either at or above their preinjury level. Of the 2 patients (3.8%) who did not return to sport, 1 did not return because of continued elbow pain postoperatively, and the other was lost to follow-up. Complications occurred in 9 patients (17.3%), all of whom were treated surgically.

Conclusion:

On the basis of this systematic review, the majority of elbow stress fractures were treated operatively and approximately one-third after a period of failed nonoperative management. The return-to-sport rate was high. Further, higher level studies are needed to optimize management and return-to-sport rates in this population.

Differentiation of bony and soft-tissue adaptations of the shoulder in professional baseball pitchers

BACKGROUND

Baseball pitching places tremendous forces on the arm, which may lead to structural tissue adaptations that are represented by changes in rotational range of motion (ROM). These adaptations often include both bony and soft tissue; however, the contribution of each tissue to the change in motion is not always clinically attainable. The purposes of this study were to determine the adaptations of ROM, bone, and soft tissue bilaterally and to examine the correlation between clinical ROM and humeral retroversion (HR)-corrected ROM. We hypothesized that glenohumeral internal rotation (IR) and total motion would be decreased and glenohumeral external rotation (ER), posterior capsule thickness (PCT), and HR would be increased in the dominant arm; that HR-corrected ROM would be significantly different than clinical ROM; and that HR-corrected ROM would be correlated with total motion difference.

METHODS

Thirty professional baseball pitchers participated in this study. HR, PCT, and glenohumeral IR and ER were evaluated in the dominant and nondominant shoulders of each subject.

RESULTS

The dominant arm exhibited significantly more retroversion, ER, and PCT than the nondominant arm. The dominant arm also had significantly less IR and total motion than the nondominant arm. The total ROM difference was significantly correlated with both HR-corrected glenohumeral IR deficit and ER gain.

CONCLUSION

HR-corrected glenohumeral IR deficit and ER gain may more accurately reflect the contribution of soft-tissue changes to ROM. Unfortunately, measurement of HR is not always clinically attainable, making clinical management difficult.

Glenohumeral internal rotation deficit in throwing athletes: current perspectives

Glenohumeral internal rotation deficit (GIRD) is an adaptive process in which the throwing shoulder experiences a loss of internal rotation (IR). GIRD has most commonly been defined by a loss of >20° of IR compared to the contralateral shoulder. Total rotational motion of the shoulder is the sum of internal and external rotation and may be more important than the absolute value of IR loss. Pathologic GIRD has been defined as a loss of IR combined with a loss of total rotational motion. The leading pathologic process in GIRD is posterior capsular and rotator-cuff tightness, due to the repetitive cocking that occurs with the overhead throwing motion. GIRD has been associated with numerous pathologic conditions, including posterior superior labral tears, partial articular-sided rotator-cuff tears, and superior labral anterior-to-posterior tears. The mainstay of treatment for patients with GIRD is posterior capsular stretching and strengthening to improve scapular mechanics. In patients who fail nonoperative therapy, shoulder arthroscopy can be performed. Arthroscopic surgery in the high-level throwing athlete should be to restore them to their functional baseline with the minimum amount of intervention possible.

Differences in humeral retroversion in dominant and nondominant sides of young baseball players

BACKGROUND

The relationship between the disabled throwing shoulder and humeral retroversion has recently attracted a great deal of attention. However, none of the previous studies clarified when the side-to-side difference of humeral retroversion in young baseball players would start. This study aimed to clarify when the difference of humeral retroversion in the dominant and nondominant sides appeared in baseball players.

METHODS

The bicipital-forearm angle in bilateral shoulders of 172 elementary school baseball players was measured by ultrasound. The bicipital-forearm angle was defined as an angle between the perpendicular line to the bicipital groove and the ulnar long axis with the elbow flexed at 90°. The correlation between the bicipital-forearm angle and the grade and the difference of the bicipital-forearm angle between the dominant and nondominant sides were analyzed.

RESULTS

In the nondominant shoulders, the bicipital-forearm angle increased with the grade in school (r = 0.32, P < .0001), but this was not observed in the dominant shoulders. In the fourth to sixth graders, the bicipital-forearm angles were significantly smaller in the dominant shoulders than in the nondominant shoulders.

CONCLUSION

Our findings indicated that humeral retroversion decreased with age in the nonthrowing side but not in the throwing side and that the side-to-side difference of humeral retroversion in the baseball players became obvious from the fourth grade. We assume that the repetitive throwing motion restricts the physiologic humeral derotation process and the difference became apparent from the fourth grade when the growth spurt begins in boys.

Olecranon physeal nonunion in the adolescent athlete: identification of two patterns

BACKGROUND

This study aimed to present the outcomes of patients undergoing surgical management of persistent, symptomatic olecranon physes.

METHODS

Consecutive patients undergoing surgical management for symptomatic persistent olecranon physeal abnormalities were reviewed. Preoperative data, intraoperative findings, and postoperative clinical outcomes including physical examination findings, radiographs, complications, and reoperations were analyzed.

RESULTS

A total of 13 elbows in 12 patients (100% male; average age, 18 ± 4 years) were identified. All patients were pitchers at the high-school or college level. Two unique radiographic patterns were identified: distal persistent olecranon physis (n = 9), identified by an irregular sclerotic lucency at the site of the olecranon physis; and proximal persistent olecranon physis (n = 4), identified by a radiolucency exiting proximal to the triceps insertion at the site of an accessory ossification center that failed to unite. Surgical management included débridement, autograft bone grafting, and internal fixation. There were 3 reoperations (1 for infection, 2 for painful hardware). All patients achieved successful radiographic union (average, 8 ± 2 weeks). At an average follow-up of 4.4 ± 1.2 years, the average postoperative Disabilities of the Arm, Shoulder, and Hand score was 1.1 ± 1.6; the Mayo Elbow Performance Score was 98.5 ± 2.4; the American Shoulder and Elbow Surgeons score was 99.3 ± 0.4; and average Likert score for satisfaction was 9.95 ± 0.2. At final follow-up, there were no significant differences in strength, motion, or stability in comparing the operative with the nonoperative elbow (P > .05 for all).

CONCLUSIONS

Two unique patterns of olecranon physeal abnormalities in young, overhead throwing athletes have been identified. Open reduction with internal fixation is clinically and radiographically successful in obtaining union and symptom resolution in these patients.

Site and Severity of the Increased Humeral Retroversion in Symptomatic Baseball Players: A 3-dimensional Computed Tomographic Analysis

BACKGROUND

Humeral retroversion in baseball players is greater in the dominant shoulder than in the nondominant shoulder. However, the site and severity of the humeral rotational deformity remain unclear.

PURPOSE

To evaluate the site of side-to-side differences in humeral retroversion in baseball players and the severity of these changes through 3-dimensional computed tomographic (3D CT) bone models.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

From 2008 to 2014, we studied 25 baseball players (12 pitchers, 13 fielders) who underwent surgery for throwing-related injuries (shoulder injury, 15 players; elbow injury, 10 players). The mean age (±SD) at the time of surgery was 20.0 ± 5.9 years. A reconstructed 3D CT model of the entire humerus was divided into 15 segments of equal height (overall mean, 21.4 ± 1.0 mm). The side-to-side difference in humeral retroversion in each segment was calculated by superimposing the model of the dominant side over the mirror-image model of the nondominant side.

RESULTS

The overall mean increase in humeral retroversion was 13.0° ± 6.2° on the dominant side. Significant side-to-side differences in retroversion were present throughout the humerus. The largest side-to-side difference in humeral retroversion was seen at the insertions of the internal rotator muscles (2.5° ± 4.3°) and around the proximal physis (2.5° ± 1.4°). At the insertions of shoulder capsule and rotator cuff tendons, the superior half of the humeral head was more retroverted than the inferior half (P < .0001). The side-to-side difference in humeral retroversion was significantly greater in the pitchers (16.2° ± 5.1°) than in the fielders (10.0° ± 5.7°) (P = .009), particularly at the proximal physis.

CONCLUSION

Baseball players exhibited significant side-to-side differences in humeral retroversion at multiple sites throughout the humerus, including the proximal humerus near the epiphyseal plate and at the insertions of the internal rotator muscles, the middle of the humeral shaft, and the distal third of the humerus. Therefore, the increased humeral retroversion at multiple sites throughout the humerus needs to be considered when we perform physical examinations, provide treatment, or undertake biomechanical studies for any throwing-related injuries.

Disproportionate trends in ulnar collateral ligament reconstruction: projections through 2025 and a literature review

BACKGROUND

Medial ulnar collateral ligament (UCL) injuries of the elbow that require surgical management are uncommon. There is growing evidence, however, suggesting that the incidence of UCL reconstruction (UCLR) procedures is rapidly increasing. We sought to quantify the incidence of age-related trends for UCLR from 2003 to 2014 and subsequently to project future trends through 2025. We hypothesized that as the total number of UCLRs performed increased, a disproportionate incidence among younger patients would be observed.

METHODS

New York State's Statewide Planning and Research Cooperative System database was queried from 2003 to 2014 to identify individuals between 10 and 40 years old undergoing UCLR. Poisson regression was used to develop future projections for UCLR and New York State population through 2025, and incidence estimates per 100,000 people were calculated.

RESULTS

In New York State between 2003 and 2014, there were 890 patients who underwent UCLR, with average annual incidence per 100,000 people equaling 6.3 ± 2.8 for ages 15 to 19 years, significantly greater than for all other age groups (P < .001). Projections from 2015 through 2025 suggest that incidence in 15- to 19-year-olds and 20- to 24-year-olds will continue to rapidly increase while rates for other age groups will remain relatively stable.

CONCLUSIONS

The number of UCLRs performed between 2003 and 2014 increased by 343%, and a disproportionate trend in average annual incidence for patients between 15 and 19 years old was observed. As our review of the literature questioned outcomes in adolescent athletes after UCLR, continued attempts at preventing these injuries in the young throwing athlete remain paramount.

The Development of Humeral Retrotorsion and Its Relationship to Throwing Sports

Context:

Several investigations have noted that throwing athletes exhibit a more posteriorly oriented humeral head (humeral retrotorsion) in the dominant arm. This asymmetry is believed to represent an adaptive response to the stress of throwing that occurs during childhood. The significance of this alteration and factors that affect its development are currently not clear.

Evidence Acquisition:

Basic science, research studies, and review articles were searched through PubMed with search terms including humeral torsion, humeral retrotorsion, and with 1 of the following: pediatric, adult, baseball, pitching, shoulder, and range of motion. The references from each article were reviewed for further inclusion. This review included articles through March 2015.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

The throwing motion creates stressors that result in bony adaptations that occur while skeletally immature. These osseous changes likely contribute to the observed shift in the arc of rotational range of motion noted in throwing athletes and may play a protective role against injury. However, too much or too little retrotorsion may predispose the shoulder to injury. The degree of “optimal” humeral retrotorsion and factors that influence its development are not fully understood.

Conclusion:

Evidence supports the assertion that the throwing motion creates stressors that alter bony anatomy while young. It is important to determine what specific factors affect this adaptation and its relationship to injury.

Ulnar Collateral Ligament Reconstruction: Anatomy, Indications, Techniques, and Outcomes

Context:

Ulnar collateral ligament (UCL) injuries lead to pain and loss of performance in the thrower’s elbow. Ulnar collateral ligament reconstruction (UCLR) is a reliable treatment option for the symptomatic, deficient UCL. Injury to the UCL usually occurs because of chronic accumulation of microtrauma, although acute ruptures occur and an acute-on-chronic presentation is also common.

Evidence Acquisition:

Computerized databases, references from pertinent articles, and research institutions were searched for all studies using the search terms ulnar collateral ligament from 1970 until 2015.

Study Design:

Clinical review.

Level of Evidence:

Level 5.

Results:

All studies reporting outcomes for UCLR are level 4. Most modern fixation methodologies appear to be biomechanically and clinically equivalent. Viable graft choices include ipsilateral palmaris longus tendon autograft, gracilis or semitendinosus autograft, and allograft. Clinical studies report excellent outcomes of UCLR for both recreational and elite level athletes with regard to return to sport and postoperative performance. Complications, although rare, include graft rerupture or attenuation, ulnar nerve symptoms, stiffness, pain, and/or weakness leading to decreased performance.

Conclusion:

Injuries to the UCL have become commonplace among pitchers. Nonoperative treatment should be attempted, but the limited studies have not shown promising results. Operative treatment can be performed with several techniques, with retrospective studies showing promising results. Complications include ulnar neuropathy as well as failure to return to sport. Detailed preoperative planning, meticulous surgical technique, and a comprehensive rehabilitation program are essential components to achieving a satisfactory result.

Upper extremity blood flow changes in professional baseball pitchers between two consecutive seasons

BACKGROUND

Because of the tremendous forces produced and the repetitive nature of baseball, players have shown various shoulder adaptations in strength and range of motion. However, no research has identified whether alterations occur in the blood flow to the dominant arm among competitive baseball players.

METHODS

Twenty professional baseball pitchers and 16 position players participated. Measurements were taken on day 1 of 2 consecutive spring training seasons. Diagnostic ultrasound was used to measure blood flow of the throwing arm brachial artery. These measurements were taken in a standing position with the test arm resting at the participant's side and again with the test arm in a provocative shoulder position. Separate 1-way analyses of variance were conducted to compare blood flow between seasons (P < .05).

RESULTS

In a resting position, the blood flow of the pitchers did not change from 1 year to the next (P = .48). However, blood flow of the pitchers in the provocative position significantly decreased after the first year (P = .009). The position players did not have any significant changes in blood flow for either arm position (P > .11).

CONCLUSIONS

In a provocative shoulder position, the blood flow of pitchers significantly decreased after 1 competitive baseball season. These results indicate that after a competitive season, the blood flow to the upper extremity of pitchers may be compromised.

Effect of distal ulnar collateral ligament tear pattern on contact forces and valgus stability in the posteromedial compartment of the elbow

BACKGROUND

It is not known whether the pattern of ulnar collateral ligament (UCL) tear affects elbow biomechanics.

HYPOTHESIS

There will be a significant change in elbow biomechanics with 50% proximal but not 50% distal simulated rupture of the UCL.

STUDY DESIGN

Controlled laboratory study.

METHODS

Pressure sensors in the posteromedial elbow joint of 25 male cadaveric elbows (average age, 54.9 years; range, 26-66 years) were used to measure contact area, pressure, and valgus torque at 90° and 30° of elbow flexion. Thirteen specimens were tested with the UCL intact, then with proximal-to-distal detachment of 50%, and then with proximal-to-distal detachment of 100% of the anterior band of the UCL from the ulnar attachment. This method was repeated in the remaining 12 specimens in a distal-to-proximal direction.

RESULTS

With 50% proximal-to-distal detachment, contact area decreased significantly versus intact at 90° (91.3 ± 23.6 vs 112.2 ± 26.0 mm(2); P < .001) and 30° (69.3 ± 14.8 vs 83.1 ± 21.6 mm(2); P < .001) of elbow flexion; the center of pressure (COP) moved significantly proximally versus intact at 90° (3.8 ± 2.5 vs 5.4 ± 2.3 mm; P < .001) and 30° (5.9 ± 2.8 vs 7.4±1.9 mm; P < .001). With 50% distal-to-proximal UCL detachment versus intact, no significant change was observed in contact area, movement of the COP, or valgus laxity at either flexion position. With 100% proximal-to-distal and distal-to-proximal detachment, significant change in contact area, movement of the COP, and valgus laxity versus intact was found at 90° and 30° of elbow flexion (P < .05). No significant difference in contact pressure was observed in any test conditions.

CONCLUSION

Significant change in contact area and proximal movement of the COP with 50% proximal UCL detachment and the lack of significant change with 50% distal UCL detachment suggest that the proximal half of the UCL ulnar footprint has a primary role in maintaining posteromedial elbow biomechanics.

CLINICAL RELEVANCE

The findings suggest that surgical reconstruction should aim to reestablish at least the proximal 50% of the UCL ulnar footprint.

Return to play after nonoperative management for a severe type III acromioclavicular separation in the throwing shoulder of a collegiate pitcher

BACKGROUND

Treatment of type III acromioclavicular (AC) separations is controversial, especially in the dominant shoulder of a high-level throwing athlete. This case report describes the return to play after nonoperative management of a collegiate baseball pitcher with a severe type III AC separation in his throwing shoulder.

HYPOTHESIS/PURPOSE

Case report of return to play with nonoperative management of a type III AC separation in the throwing shoulder of a collegiate pitcher.

STUDY DESIGN

A case report of a single patient.

METHODS

Prospective data were recorded in the case of a collegiate pitcher who suffered an acute injury to the dominant shoulder, resulting in a severe type III AC separation. He was initially treated with a figure-of-8 brace and a sling. Postinjury, strengthening of the wrist, hand, and elbow began at 3½ weeks, and shoulder range of motion (ROM) and a periscapular strengthening program began at 6 weeks. At 2 months postinjury, a deformity was still present, but the athlete was pain free, with full shoulder ROM and strength without tenderness at the AC joint. Formal physical therapy was initiated to include an accelerated interval throwing program.

RESULTS

At 12 weeks postinjury, the athlete was pitching asymptomatically, and gradually returned to regular play. At 6 months and now through 24 months postinjury, the athlete reported full strength, full ROM, and return to his previous level of throwing and velocity without complication. He volunteered that he was 100% satisfied with the result, and feels he is the same pitcher as, if not stronger than, prior to this injury.

CONCLUSIONS

This case demonstrates a collegiate baseball pitcher who returned to his preinjury level of pitching with nonoperative treatment of a severe type III AC separation.

Decreased blood flow in the throwing arm of professional baseball pitchers

BACKGROUND

As a consequence of the repetitive forces placed on the throwing arm of a baseball player, various bony, capsuloligamentous, and muscular adaptations occur and have been identified. However, no research has identified whether adaptations also exist in the vasculature of the upper extremity in the competitive baseball player.

METHODS

Fifty-one professional baseball pitchers and 34 position players participated. Diagnostic ultrasound was used to measure bilateral blood flow of the brachial artery. These measurements were taken with the participant standing with the test arm resting at the participant's side and again with the test arm in a provocative shoulder position.

RESULTS

The throwing arm of the pitchers had significantly less blood flow volume when in the provocative shoulder position compared with their nonthrowing arm (P = .01). Pitchers did not have any bilateral difference while in the resting position (P = .19). There were no bilateral differences among the position players while in the resting (P = .64) or provocative positions (P = .63). Pitchers had significantly less blood flow of the throwing shoulder while in the provocative position compared with position players (P = .02). There were no other between-group differences.

CONCLUSIONS

While in a provocative shoulder position, pitchers have significantly less blood flow in their throwing arm compared with their nonthrowing arm and with the throwing arm of position players. These results provide a descriptive profile of blood flow volume among baseball players, which may be used in the evaluation and treatment of such athletes with vascular disorders.

Acute effects of instrument assisted soft tissue mobilization for improving posterior shoulder range of motion in collegiate baseball players

BACKGROUND

Due to the repetitive rotational and distractive forces exerted onto the posterior shoulder during the deceleration phase of the overhead throwing motion, limited glenohumeral (GH) range of motion (ROM) is a common trait found among baseball players, making them prone to a wide variety of shoulder injuries. Although utilization of instrument-assisted soft tissue mobilization (IASTM), such as the Graston® Technique, has proven effective for various injuries and disorders, there is currently no empirical data regarding the effectiveness of this treatment on posterior shoulder tightness.

PURPOSE

To determine the effectiveness of IASTM in improving acute passive GH horizontal adduction and internal rotation ROM in collegiate baseball players.

METHODS

Thirty-five asymptomatic collegiate baseball players were randomly assigned to one of two groups. Seventeen participants received one application of IASTM to the posterior shoulder in between pretest and posttest measurements of passive GH horizontal adduction and internal rotation ROM. The remaining 18 participants did not receive a treatment intervention between tests, serving as the controls. Data were analyzed using separate 2× 2 mixed-model analysis of variance, with treatment group as the between-subjects variable and time as the within-subjects variable.

RESULTS

A significant group-by-time interaction was present for GH horizontal adduction ROM with the IASTM group showing greater improvements in ROM (11.1°) compared to the control group (-0.12°) (p <0.001). A significant group-by-time interaction was also present for GH internal rotation ROM with the IASTM group having greater improvements (4.8°) compared to the control group (-0.14°) (p < 0.001).

CONCLUSIONS

The results of this study indicate that an application of IASTM to the posterior shoulder provides acute improvements in both GH horizontal adduction ROM and internal rotation ROM among baseball players.

LEVEL OF EVIDENCE

2b.

Thoracolumbar range of motion in baseball pitchers and position players

INTRODUCTION/BACKGROUND

Optimal baseball throwing mechanics require a significant contribution of thoracolumbar motion, particularly in the sagittal and transverse planes. This motion is key for proper transmission of forces from the lower to upper extremity, thereby minimizing a throwing athlete's risk of injury and maximizing athletic performance.

PURPOSE

To define the active-assisted thoracolumbar ROM of both baseball pitchers and position players and to compare these motions both within and between groups.

METHODS

Fifty-six asymptomatic, collegiate and minor league baseball pitchers and 42 position players volunteered to participate. Active-assisted thoracolumbar flexion, extension, and bilateral rotation ROM, were measured in a standing position, using two bubble inclinometers. Two-tailed t tests were used to determine differences in ROM between and within the pitchers and position players.

RESULTS

The pitchers had significantly more rotation to the non-throwing arm side as compared to the position players (p = .007, effect size = .61). The pitchers also had more rotation to the non-throwing arm side as compared to their throwing side (p = .006, effect size = .47). There were no other significant differences between the pitchers and the position players (p > .53). Furthermore, the position players did not have a side-to-side rotation difference (p = .99).

CONCLUSIONS

Pitchers have a greater amount of rotation ROM towards the non-throwing arm side as compared to position players. Pitchers also have a greater amount of rotation ROM to the non-throwing arm side as compared to their throwing side rotation. Because pitchers often present with posterior shoulder tightness and subsequent altered shoulder horizontal adduction and internal rotation ROM, the increase in non-throwing side rotation ROM may occur in response to these adaptations. More specifically, this increase in non-throwing side trunk rotation ROM may allow such athletes to bring the arm across the body during the follow-through phase of the throwing motion despite posterior shoulder tightness. However, future research is necessary to investigate this relationship. Based on these results, clinicians should consider these thoracolumbar ROM adaptations in the prevention, evaluation, and treatment of baseball players.

LEVEL OF EVIDENCE

2b.

Shoulder pain in the overhead throwing athlete

Treatment of the overhead throwing athlete is among the more challenging aspects of orthopaedic sports medicine. Awareness and understanding of the throwing motion and the supraphysiologic forces to which the structures of the shoulder are subjected are essential to diagnosis and treatment. Pain and dysfunction in the throwing shoulder may be attributed to numerous etiologies, including scapular dysfunction, intrinsic glenohumeral pathology (capsulolabral structures), extrinsic musculature (rotator cuff), or neurovascular structures. Attention to throwing mechanics and appropriate stretching, strength, and conditioning programs may reduce the risk of injury in this highly demanding activity. Early discovery of symptoms, followed by conservative management with rest and rehabilitation with special attention to retraining mechanics may mitigate the need for surgical intervention. Prevention of injury is always more beneficial to the long-term health of the thrower than is surgical repair. An anatomic approach is used in this report, focusing on common etiologies of pain in the overhead thrower and emphasizing the clinical presentation and treatment.

Clinical Evaluation of the Athlete's Shoulder

OBJECTIVE

To describe the history and physical examination of the athlete's shoulder.

BACKGROUND

The complex, highly mobile shoulder joint is very susceptible to athletic injury. A comprehensive history and physical examination lay the groundwork for accurate decision making about the nature of the injury and the appropriate treatment plan.

DESCRIPTION

In taking the history,inquire about the patient's lifestyle (dominant hand, occupation, sports, activity level) and then focus on the specific complaint. Ask about the location, quality, and nature of the pain and activities that provoke the pain. If stiffness is a factor, a review of systems and the patient's past medical history are important. Discuss any previously undertaken interventions and their effects. The physical examination consists of inspection, range of motion, palpation, manual muscle testing, and provocative tests.

CLINICAL ADVANTAGES

Once the clinical evaluation has been completed, the nature of the injury will, in most cases, be apparent. If necessary, appropriate diagnostic tests are ordered, and then a treatment plan tailored to the athlete and the injury is instituted.