Ulnar Collateral Ligament Reconstruction of the Elbow: A Systematic Review of the Literature

Return to Play and In-Game Performance Statistics Among Pitchers After Ulnar Collateral Ligament Reconstruction of the Elbow: A Systematic Review

BACKGROUND

Injury to the ulnar collateral ligament of the elbow is relatively common among baseball pitchers. Ulnar collateral ligament reconstruction (UCLR) has revolutionized the management of this injury, allowing a greater proportion of pitchers to return to play.

PURPOSE

To assess the return to play and in-game performance specific to baseball pitchers who have undergone primary UCLR.

STUDY DESIGN

Systematic review.

METHODS

This review was conducted according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The electronic databases MEDLINE, EMBASE, and PubMed were searched for relevant studies, and pertinent data were abstracted. Only studies reporting in-game performance statistics (earned run average [ERA], pitching velocity, innings pitched per season, etc) of pitchers after UCLR were included. The methodological index for nonrandomized studies (MINORS) was used to assess study quality.

RESULTS

A total of 14 studies and 1520 pitchers were included in this systematic review. All studies were of level 3 or 4 evidence, and the mean ± SD MINORS score was 14.4 ± 3.0, which indicates fair quality of evidence for nonrandomized studies. The rates of return to any level of pitching after UCLR ranged from 79% to 100%. Subgroup analysis revealed that 79% to 87% of Major League Baseball (MLB) pitchers returned to preinjury levels of pitching. The mean time to return to play was 19.8 ± 13.5 months, and the mean time to return to competition for MLB pitchers was 17.3 ± 2.4 months. Of the 5 studies reporting ERA, 2 cited a significant increase after UCLR, and 1 indicated a significant decrease. Of the 4 studies reporting fastball velocity, 3 cited decreased pitching velocities after UCLR. All studies found that pitchers pitched, on average, fewer innings per game or season after UCLR.

CONCLUSION

There was a high rate of return to pitching after UCLR. However, most studies showed that UCLR was associated with a prolonged recovery and significant decline in pitching performance as objectively measured by in-game statistics. The strength of these conclusions is limited by the quality of the available literature and inconsistencies in the reporting of outcomes.

Open Reduction Internal Fixation of Medial Epicondyle Fractures After Ulnar Collateral Ligament Reconstruction in Professional Baseball Pitchers

Background:

Ulnar collateral ligament reconstruction (UCLR) is a common procedure among professional baseball pitchers. An uncommon complication after UCLR is a fracture of the medial epicondyle at the level of the humeral tunnel, which requires open reduction internal fixation (ORIF).

Purpose/Hypothesis:

The purpose of this study was to determine the performance upon and rate of return to sport (RTS) in professional baseball pitchers after ORIF of the medial epicondyle and examine whether there is a difference in the RTS rate and performance between players who underwent ORIF and matched controls. It was hypothesized that there would be a high rate of RTS in professional baseball pitchers after ORIF of the medial epicondyle, with no difference between the ORIF and control groups in the rate of RTS or performance, specifically related to the primary performance outcome variables of win-loss percentage, walks plus hits per inning pitched, fielding independent pitching, and wins above replacement.

Methods:

All professional baseball pitchers who underwent ORIF of the medial epicondyle between 2010 and 2016 were included in this study. Demographic and performance data (preoperative and postoperative) were recorded for each player. Performance metrics were then compared between the ORIF and control (no history of UCLR or ORIF) groups.

Results:

Overall, 15 pitchers (80.0% starters, 73.3% right-handed) underwent ORIF of a medial epicondyle fracture. All had undergone prior UCLR using either the American Sports Medicine Institute (n = 9; 60.0%) or docking (n = 6; 40.0%) technique. ORIF techniques included fixation with 1 screw (n = 13; 86.7%) and fixation with suture anchors (n = 2; 13.3%). Eleven (73.3%) pitchers were able to return to sport (did not differ from controls; P = .537); 55% returned to the same level or higher. No significant differences existed in the primary performance outcome variables when comparing preoperative with postoperative performance. No significant differences in the primary performance outcome variables were seen between the ORIF and control groups after surgery, although players in the ORIF group pitched fewer innings than controls after surgery (P = .003).

Conclusion:

After ORIF of the medial epicondyle in professional pitchers with a history of UCLR, 73.3% were able to return to sport (only 55% of those who returned pitched at the same level or higher) without a significant decline in most performance variables when compared with their preoperative performance or matched controls. The number of innings pitched declined after surgery.

Comparison of Outcomes Based on Graft Type and Tunnel Configuration for Primary Ulnar Collateral Ligament Reconstruction in Professional Baseball Pitchers

BACKGROUND

Professional baseball pitchers are at high risk for tears of the ulnar collateral ligament (UCL) of the elbow, often requiring surgical reconstruction. Despite acceptable published return-to-play outcomes, multiple techniques and graft types have been described.

PURPOSE

This study compares UCL reconstruction (UCLR) outcomes based on tunnel configuration and graft type.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

After approval from our institutional review board and Major League Baseball (MLB), 566 professional baseball pitchers who underwent UCLR between 2010 and 2014 were identified and included. The following patient characteristics were analyzed: age, pitching role (starter vs reliever), level of play (MLB vs Minor League Baseball [MiLB]), and throwing side dominance. Surgical factors analyzed included reconstruction technique, graft type, and concomitant procedures. Primary outcome measures consisted of the ability to return to play at any level (RTP), ability to return to the same level of play (RSL), time to return, subsequent elbow injuries, and need for subsequent or revision elbow surgery. The effects of patient and surgical factors on outcomes were analyzed using multivariate linear and logistic regression modeling.

RESULTS

The RTP rate was 79.9%, and the RSL rate was 71.2%. Grafts used to reconstruct the UCL included the palmaris longus autograft (n = 361, 63.7%), the gracilis autograft (n = 135, 23.8%), and other grafts (n = 70, 12.5%). Surgical techniques utilized were the docking technique (n = 171, 30.2%), the modified Jobe technique (n = 290, 51.2%), and other techniques (n = 105, 18.6%). There were no significant differences in the time to RTP or RSL based on reconstruction technique or graft type. RTP rates were similar for the docking versus modified Jobe technique (80.1% vs 82.4%, respectively; P = .537) and for the 2 primary graft types (83.1% for palmaris longus vs 80.7% for gracilis; P = .596). The rate of subsequent elbow surgery was 10.5% for the docking technique versus 14.8% for the modified Jobe technique ( P = .203), and the rate of revision UCLR was 2.9% versus 6.2% for the docking versus modified Jobe technique, respectively ( P = .128). Significant trends toward an increasing use of the palmaris longus autograft ( P = .023) and the docking technique ( P = .006) were observed. MLB pitchers were more likely than MiLB pitchers to RTP ( P < .001) and RSL ( P < .001), but they required a longer time to return (mean difference, 35 days; P = .039) and had a higher likelihood of subsequent elbow (odds ratio [OR], 3.58 [95% CI, 2.06-6.23]; P < .001) and forearm injuries (OR, 5.70 [95% CI, 1.99-16.30]; P = .004) but not subsequent elbow surgery. No specific variables correlated with the rates of subsequent elbow surgery or revision UCLR in the multivariate analysis. The use of concomitant ulnar nerve transposition did not affect outcomes.

CONCLUSION

Surgical outcomes in professional baseball players are not significantly influenced by UCLR technique or graft type. There was a high rate (46.3%) of subsequent throwing elbow injuries. MLB pitchers were more likely to RTP and RSL, but they had a higher frequency of subsequent elbow and forearm injuries than MiLB pitchers. Both the docking technique and the palmaris longus autograft are increasing in popularity among surgeons treating professional baseball players.

The Middle and Distal Aspects of the Ulnar Footprint of the Medial Ulnar Collateral Ligament of the Elbow Do Not Provide Significant Resistance to Valgus Stress: A Biomechanical Study

Background

The medial ulnar collateral ligament (UCL) insertion of the elbow has been shown to extend distally beyond the sublime tubercle. The contribution to valgus stability of the distal aspect of the footprint is unknown.

Purpose/Hypothesis

The purpose of this study was to determine the contribution of each part of the UCL footprint to the elbow valgus stability provided by the UCL. It was hypothesized that the distal two-thirds of the ulnar UCL footprint would not contribute significantly to valgus stability provided by the UCL.

Study Design

Descriptive laboratory study.

Methods

Fifteen cadaveric arms were dissected to the capsuloligamentous elbow structures and potted. A servohydraulic load frame was used to place 5 N·m of valgus stress on the intact elbow at 30°, 60°, 90°, and 120° of flexion. The UCL insertional footprint was measured and divided into thirds (proximal, middle, and distal). One-third of the UCL footprint was elevated off the bone (leaving the ligament in continuity), and the elbow was retested at the same degrees of flexion. This was repeated until the entire UCL footprint on the ulna was sectioned. Each elbow was randomized for how the UCL would be sectioned (sectioning the proximal, then middle, and then distal third or sectioning the distal, then middle, and then proximal third). Ulnohumeral joint gapping (millimeters) was recorded with a 3-dimensional motion capture system using physical and virtual markers. Two-group comparisons were made between each sectioned status versus the intact condition for each flexion angle.

Results

When the UCL was sectioned from distal to proximal, none of the ligaments failed prior to complete sectioning. When the UCL was sectioned from proximal to distal, 3 of the 6 ligaments failed after sectioning of the proximal third, while 2 more failed after the proximal and middle thirds were sectioned. Of the specimens with the distal third of the ligament sectioned first, no significant differences were found between intact, distal third cut, and distal plus middle thirds cut at all flexion angles.

Conclusion

The middle and distal thirds of the insertional footprint of the UCL on the ulna did not significantly contribute to gap resistance at 5 N·m of valgus load. The proximal third of the footprint is the primary resistor of valgus load.

Clinical Relevance

This cadaveric biomechanical study demonstrated that the middle and distal thirds of the native UCL insertion onto the ulna did not significantly contribute to valgus resistance at the elbow. When a UCL reconstruction is performed, the proximal third of the UCL insertion may be the most clinically important portion of the ligament to reconstruct.

Hamstring Injuries in Major League Baseball Pitchers: Implications in Graft Selection for Ulnar Collateral Ligament Reconstruction

BACKGROUND

Hamstring tendons are commonly harvested as autograft for ulnar collateral ligament reconstruction. There is no consensus in the literature whether the hamstring tendon should be harvested from the ipsilateral (drive) leg or contralateral (landing) leg of baseball pitchers undergoing ulnar collateral ligament reconstruction. Hamstring injuries commonly occur in baseball players, but there are no reports on their incidence specifically among Major League Baseball (MLB) pitchers, nor are there reports on whether they occur more commonly in the drive leg or the landing leg.

HYPOTHESIS

Hamstring injuries occur more commonly in the landing legs of MLB pitchers.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

MLB pitchers who sustained hamstring injuries requiring time spent on the disabled list were identified from publicly available sources over 10 seasons. Demographics of the pitchers and injury and return-to-sport data were collected. Hamstring injuries to the drive leg were compared with injuries to the landing leg.

RESULTS

Sixty-five pitchers had 78 disabled list stints due to hamstring injuries over 10 seasons. The landing leg was injured in 67.9% of cases, and the most common mechanism of injury was pitching. There were no significant differences in demographics between pitchers who sustained drive leg and landing leg injuries. There was no significant difference in mechanism of injury or time to return to sport between pitchers who sustained drive leg and landing leg injuries.

CONCLUSION

The landing leg is more commonly injured than the drive leg among MLB pitchers who sustain hamstring injuries. There is no difference in time to return to sport between pitchers who sustain drive leg and landing leg injuries. More research is required to determine whether there is a difference in performance or future injury between hamstring tendons harvested from the drive leg and the landing leg for ulnar collateral ligament reconstruction among pitchers.

Elbow Ulnar Collateral Ligament Reconstruction Using the Novel Docking Plus Technique in 324 Athletes

BACKGROUND

This retrospective case series examined 324 athletes who received elbow ulnar collateral ligament (UCL) reconstruction by a single surgeon in a private practice over a 9-year period. The novel Docking Plus technique for elbow UCL reconstruction in 324 athletes provided good or excellent Conway score results in 88% of patients. The preponderance of previous studies examining UCL reconstruction outcomes were performed by surgeons at one of only three institutions (Andrews Institute, Hospital for Special Surgery, Kerlan Jobe Orthopedic Clinic).

METHODS

Patients undergoing UCL reconstruction from November 2005 to December 2014 were identified and contacted with a mailed survey and phone call. These patients were given a subjective 19 question survey assessing their outcomes from surgery.

RESULTS

The participants who responded to our survey were 90% male and 77% baseball players, 73% of which were pitchers. Of the baseball players who responded, 51.9% were in high school at the time of their surgery, 37% college, 6.5% minor leagues, and 2.2% in Major League Baseball. After surgery, 36% of survey responders returned to a higher level of competition than previously. For example, a high school athlete who had UCL reconstruction and went on to pitch in college. Further, 45% returned to the same level, and 7% returned to a lower level. Subjective "satisfaction," was reported in 92% of responders and 97.2% reported that, "having surgery was a good idea." Symptom onset in the responding athletes was 58.9% sudden, and 41.1% gradual. Overall, 90.9% of respondents returned to play in less than 1.5 years while 6.3% never were able to return. Re-tear occurred in 2.5% of patients, while 8.8% had subjective nerve dysfunction for at least 3 months following surgery.

CONCLUSION

The Docking Plus technique can produce excellent subjective and objective results in athletes. Further study is warranted to see the effects of this procedure in other settings and determine which method of reconstruction or repair is superior.

Repair of the ulnar collateral ligament of the elbow with internal brace augmentation: a 5-year follow-up

The ulnar collateral ligament (UCL) is the primary restraint to valgus angulation at the elbow. Injury to the UCL is increasingly common and can lead to instability, especially in athletes involved in overhead throwing. Conventional treatment is reconstruction using tendon autograft but performance levels are often restricted after long periods of rehabilitation. Modern surgical techniques have led to renewed interest in repair of the ligament, with the aim of restoring native anatomy. This has the benefit of retained proprioception and no graft harvest morbidity. Furthermore, augmentation of the repair with an Internal Brace protects the healing ligament, while allowing early rehabilitation and accelerated return to play. Here we present the first patient treated with this technique who achieved excellent recovery with return to college level American Football after 4 months. Five years later he has good elbow function and plays at the same level.

Biomechanical analysis of elbow medial ulnar collateral ligament tear location and its effect on rotational stability

BACKGROUND

Recent anatomic and clinical studies have shown that the location of the injury to the elbow ulnar collateral ligament (UCL) is an important variable in deciding on surgical intervention; however, no studies have evaluated these findings biomechanically.

METHODS

This study tested 16 intact elbow specimens. Valgus torques of 2.5 and 5 Nm were applied to the elbow at various flexion angles, and the resulting valgus angles were measured. The valgus angles were applied to the elbows in their intact states and again after partial and complete cuts were made on the proximal and distal insertions of the UCL. Resulting valgus torques were measured, and stiffness was calculated for each elbow flexion angle. Unpaired t tests were used to evaluate the effects of cut location and flexion angle on joint rotational stability and stiffness.

RESULTS

The posterior-distal insertion contributed the most to stability. At valgus angles generated from 2.5 Nm intact torques, the posterior-distal insertions contributed to 51% ± 26% (P < .03) intact rotational stability, and at valgus angles generated from 5 Nm intact torques, the posterior-distal insertions contributed to 41% ± 17% (P < .02) intact rotational stability. For overall stiffness, the posterior-distal insertions contributed to 31% ± 12% (P < .045) intact stiffness.

CONCLUSION

Overall, the posterior distal insertion of the UCL contributed most to rotational stability and stiffness of the medial elbow when subjected to valgus stress at 90° and 120° of elbow flexion. At higher elbow flexion angles, the posterior insertions contributed more to stability, whereas the anterior insertions had a greater effect at lower flexion angles.

Following ulnar collateral ligament reconstruction, professional baseball position players return to play faster than pitchers, but catchers return less frequently

BACKGROUND

Although much as been done to characterize trends of medial ulnar collateral ligament (UCL) reconstruction in pitchers, outcomes in position players (PPs) (non-pitchers) remain undefined in the current literature.

METHODS

Three resources were combined to identify all known Major League Baseball and Minor League Baseball (MiLB) PPs who have ever undergone UCL reconstruction. A multitude of player and surgical variables were included. Trends over time were analyzed collectively, based on level of play, revision status (primary vs revision), and position. Additional comparisons were made with a known cohort of professional baseball pitchers having undergone UCL reconstruction.

RESULTS

We identified 168 UCL reconstructions in professional PPs. The annual rate of primary UCL reconstruction rose significantly from 1984 to 2015 (P < .001), and the proportion of cases performed in MiLB PPs (vs Major League Baseball PPs) increased steadily (P < .001). Of PPs, 75.5% returned to play at any level at a mean of 342 days. Catchers demonstrated the lowest return-to-play (RTP) rate (58.6%) compared with infielders (75.6%) and outfielders (88.9%). The overall revision rate was low, at 4.8%. Compared with pitchers, PPs demonstrated a lower rate of RTP (75.5% for PPs vs 83.7% for pitchers, P = .040) but shorter RTP times for those able to return (342 days for PPs vs 435 days for pitchers, P < .001).

CONCLUSIONS

The incidence of UCL reconstruction in PPs continues to rise, a trend that is significantly more pronounced at the MiLB level. Although PPs (particularly catchers) are less likely to return to professional baseball compared with pitchers, those who are able to RTP do so more rapidly.

Epidemiology of ulnar collateral ligament reconstruction in Major and Minor League Baseball pitchers: comprehensive report of 1429 cases

BACKGROUND

The primary purpose of this work is to provide an epidemiologic report on every known ulnar collateral ligament (UCL) reconstruction performed in professional baseball with a special focus on outcomes and survivorship.

METHODS

Three resources, including the Major League Baseball (MLB) injury tracking system, were combined and cross-referenced to identify all known professional baseball pitchers who had ever undergone UCL reconstruction from 1974 to 2016. Variables analyzed included injury date, surgery date, return to play rates, time out of play, and revision status. Trends over time were analyzed collectively and by level of play at the time of surgery. A minimum of 2 years of follow-up was required for return to play analysis.

RESULTS

We identified 1429 UCL reconstructions. The annual rate of primary and revision UCL reconstructions rose significantly (P < .001). Most players (83.7%) returned to any level of play at a mean of 435 days, whereas 72.8% (P < .001) returned to their prior level at a mean of 506 days. Major League Baseball players were more likely than Minor League Baseball players to return to any level (94.6% vs. 79.0%, P < .001) and their prior level of performance (80.0% vs. 69.1%, P = .04). The mean overall survivorship free from revision and still playing was 3.8 years (3.9 for primary vs. 2.9 for revisions, P = .018). The revision rate was 6.7% and was higher for Major League Baseball (9.4%) vs. Minor League Baseball (5.2%, P = .004).

CONCLUSIONS

This study represents the most robust epidemiologic report of UCL reconstruction in baseball to date, and a multitude of novel findings are reported.

Outcomes and Return to Sport After Ulnar Collateral Ligament Reconstruction in Adolescent Baseball Players

Background:

The number of ulnar collateral ligament (UCL) reconstructions in adolescent athletes has increased over the past 2 decades. Clinical results in this population have not been well studied.

Purpose/Hypothesis:

The purpose of this study was to evaluate the outcomes and return to sport after UCL reconstruction in a large group of adolescent baseball players. We hypothesized that excellent clinical outcomes and high rates of return to sport would be observed in this population at a minimum 2-year follow-up.

Study Design:

Case series; Level of evidence, 4.

Methods:

We reviewed 140 adolescent (aged ≤19 years) baseball players who underwent UCL reconstruction with the American Sports Medicine Institute (ASMI) technique by a single surgeon. Medical records were reviewed for patient demographics, injury characteristics, operative details, and surgical complications. Patient-reported outcomes were assessed using the Conway scale, the Andrews-Timmerman (A-T) score, the Kerlan-Jobe Orthopaedic Clinic (KJOC) score, and a 0- to 100-point subjective scale for elbow function and satisfaction. Return to sporting activity was assessed using a custom-designed questionnaire.

Results:

The mean age at the time of surgery was 18.0 years (range, 13-19 years), and the mean follow-up was 57.9 months (range, 32.4-115.4 months). Over half (60%) of patients were high school athletes. The mean duration of symptoms before surgery was 6.9 months (range, 0.5-60.0 months). Partial tears were identified in 57.9% of patients, and 41.3% of patients had preoperative ulnar nerve symptoms. Graft type included the ipsilateral palmaris in 77.1% of patients. Concomitant procedures were performed in 25% of patients. Outcomes on the Conway scale were “excellent” in 86.4% of patients. The mean A-T and KJOC scores were 97.3 ± 6.1 and 85.2 ± 14.6, respectively. Mean patient satisfaction was 94.4. Overall, 97.8% of patients reported returning to sport at a mean of 11.6 months (range, 5-24 months), and 89.9% of patients returned to sport at the same level of competition or higher. A total of 11.6% of patients went on to play professional baseball.

Conclusion:

UCL reconstruction with the ASMI technique is an effective surgical option in adolescents, with excellent outcome scores. At a minimum of 2-year follow-up, nearly 90% of patients returned to their preinjury level of sport.

Osseous Vascularity of the Medial Elbow After Ulnar Collateral Ligament Reconstruction: A Comparison of the Docking and Modified Jobe Techniques

Background

Although vascularity plays a critical role in healing after ulnar collateral ligament (UCL) reconstruction, intraosseous blood flow to the medial epicondyle (ME) and sublime tubercle remains undefined.

Purpose

To quantify vascular disruption caused by tunnel drilling with the modified Jobe and docking techniques for UCL reconstruction.

Study Design

Controlled laboratory study.

Methods

Eight matched pairs (16 specimens) of fresh-frozen cadaveric upper extremities were randomized to 1 of 2 study groups: docking technique or modified Jobe technique. One elbow in each pair underwent tunnel drilling by the assigned technique, while the contralateral elbow served as a control. Pregadolinium and postgadolinium magnetic resonance imaging were performed to quantify intraosseous vascularity within the ME, trochlea, and proximal ulna. Three-dimensional computed tomography (CT) and gross dissection were performed to assess terminal vessel integrity.

Results

Ulnar tunnel drilling had minimal impact on vascularity of the proximal ulna, with maintenance of >95% blood flow for each technique. Perfusion in the ME was reduced 14% (to 86% of baseline) for the docking technique and 60% (to 40% of baseline) for the modified Jobe technique (mean difference, 46%; P = .029). Three-dimensional CT and gross dissection revealed increased disruption of small perforating vessels of the posterior aspect of the ME for the modified Jobe technique.

Conclusion

Although tunnel drilling in the sublime tubercle appears to have a minimal effect on intraosseous vascularity of the proximal ulna, both the docking and modified Jobe techniques reduce flow in the ME. This reduction was 4 times greater for the modified Jobe technique, and these findings have important implications for UCL reconstruction surgery.

Clinical Relevance

As the rate of revision UCL reconstructions continues to rise, investigation into causes for failure of primary surgery is needed. One potential cause is poor tendon-to-bone healing due to inadequate vascularity. This study quantifies the amount of vascular insult that is incurred in the ME during UCL reconstruction. While vascular insult is only one of many factors that affects the surgical success rate, surgeons performing this procedure should be mindful of this potential for vascular disruption.

Quantitative Anatomic Analysis of the Medial Ulnar Collateral Ligament Complex of the Elbow

Background

A more detailed assessment of the anatomy of the entire medial ulnar collateral ligament complex (MUCLC) is desired as the rate of medial elbow reconstruction surgery continues to rise.

Purpose

To quantify the anatomy of the MUCLC, including the anterior bundle (AB), posterior bundle (PB), and transverse ligament (TL).

Study Design

Descriptive laboratory study.

Methods

Ten unpaired, fresh-frozen cadaveric elbows underwent 3-dimensional (3D) digitization and computed tomography with 3D reconstruction. Ligament footprint areas and geometries, distances to key bony landmarks, and isometry were determined. A surgeon digitized the visual center of each footprint, and this location was compared with the geometric centroid calculated from the outline of the digitized footprint.

Results

The mean surface area of the AB was 324.2 mm², with an origin footprint of 32.3 mm² and an elongated insertional footprint of 187.6 mm² (length, 29.7 mm). The mean area of the PB was 116.6 mm² (origin, 25.9 mm²; insertion, 15.8 mm²), and the mean surface area of the TL was 134.5 mm² (origin, 21.2 mm²; insertion, 16.7 mm²). The geometric centroids of all footprints could be predicted within 0.8 to 1.3 mm, with the exception of the AB insertion centroid, which was 7.6 mm distal to the perceived center at the apex of the sublime tubercle. While the PB remained relatively isometric from 0° to 90° of flexion (P = .606), the AB lengthened by 2.2 mm (P < .001).

Conclusion

Contrary to several historical reports, the insertional footprint of the AB was larger, elongated, and tapered. The TL demonstrated a previously unrecognized expansive soft tissue insertion directly onto the AB, and additional analysis of the biomechanical contribution of this structure is needed.

Clinical Relevance

These findings may serve as a foundation for future study of the MUCLC and help refine current surgical reconstruction techniques.

The success of return to sport after ulnar collateral ligament injury in baseball: a systematic review and meta-analysis

BACKGROUND

Ulnar collateral ligament injury (UCLI) has significantly increased in overhead sports during the past 2 decades. Differences in return to sport (RTS) and RTS at previous level (RTSP) after UCLI have not been differentiated.

METHODS

A computer-assisted literature search of PubMed, CINAHL, Embase, and SportDiscus databases using keywords related to RTS for UCLI was implemented. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used for study methodology. Quality assessment was conducted using a modified Downs and Black scale.

RESULTS

A total of 22 retrospective, level 3b or 4, studies (n = 2289) qualified for analysis. Overall RTS proportion was 90% (95% confidence interval [CI], 86%-94%) and overall RTSP proportion was 79% (95% CI, 75%-84%), both with significant heterogeneity (P < .001, I² = 74%-84%). RTS and RTSP proportions were 89% (95% CI, 83%-94%) and 78% (95% CI, 72%-83%) for Major League Baseball players, 91% (95% CI, 77%-99%) and 67% (95% CI, 52%-81%) for Minor League Baseball players, 95% (95% CI, 75%-100%) and 92% (95% CI, 82%-98%) for collegiate players, and 93% (95% CI, 81%-100%) and 83% (95% CI, 77%-89%) for high school players, respectively. Increased earned run average, walks, and hits per inning pitched, decreased innings pitched, and decreased fastball velocity were found after UCLI.

CONCLUSION

Low-level, high-bias evidence demonstrates overall RTS proportion is higher than RTSP, regardless of treatment type for UCLI. Although RTS proportions remained consistent across various levels of play, RTSP proportions were lower in professional players, particularly Minor League Baseball compared with collegiate and high school players. Pitching performance significantly decreased postoperatively in most studies.

Elbow Injuries in the Adolescent Thrower

PURPOSE OF REVIEW

With an increasing rate of adolescent elbow injuries, especially in throwing athletes, the purpose of this review is to investigate the current literature regarding the diagnosis, treatment, and non-operative and operative outcomes of medial epicondyle fractures, ulnar collateral ligament repair, osteochondritis dissecans of the elbow, and olecranon stress fractures.

RECENT FINDINGS

Acceptable outcomes with both non-operative and operative treatments of medial epicondyle fractures have been reported, with surgical indications continuing to evolve. Unstable osteochondritis dissecans lesions, especially in patients with closed growth plates, require operative fixation, and emerging open and arthroscopic techniques including lesion debridement, marrow stimulation, autograft transfer, and allograft transplantation are described with good outcomes. Ulnar collateral repair has emerged as an exciting treatment option for an avulsion of either end of the ligament in young throwing athletes, with faster rehabilitation times than traditional ulnar collateral ligament reconstruction. Olecranon stress fractures are increasing in prevalence, and when a non-operative treatment course is unsuccessful, athletes have a high return-to-play rate after percutaneous cannulated screw placement. With proper indications, non-operative and operative treatment modalities are reported with a high return-to-play and acceptable clinical outcomes for common elbow injuries, including medial epicondyle fractures, ulnar collateral ligament repair, osteochondritis dissecans of the elbow, and olecranon stress fractures, in adolescent throwing athletes. Further research is needed to better define treatment algorithms, surgical indications, and outcomes.

Return to Throwing after Shoulder or Elbow Injury

PURPOSE OF REVIEW

Throwing places high demands on the human body, and specific characteristics are developed over time unique to these athletes. When returning to throw after injury, it is important to follow a criterion-based progression that allows the body to be prepared appropriately for the stresses that throwing will require. There is currently a void in the literature for criteria-based progression that helps these athletes return to the highest level of play.

RECENT FINDINGS

As injury rates continue to rise in baseball, there is increased evidence showing contributions of the core and lower extremity to the baseball pitch. There is also additional data showing pitcher specific characteristics such as range of motion and scapular position in this unique population. The rehab professional should take into account every phase of the pitch starting from balance through ball release when designing a comprehensive return-to-throwing program. Returning an athlete back to a throwing sport can be an overwhelming task. The rehabilitation specialist must have a sound understanding of the throwing motion as well as any biomechanical implications on the body, contributions throughout the kinetic chain, range of motion, and strength characteristics specific to the thrower as well as proper tissue loading principles. It is important that these athletes are not progressed too quickly through their programs and that a criteria-based progression is followed. They should have normalized range of motion, strength, and scapular mechanics, followed by a sound plyometric progression. Once this is achieved, they are advanced to an interval throwing program with increasing distance, effort, and volume which should be tracked for workload, making sure they do not throw more than their body is prepared for.

Systematic Review of Outcomes Reporting in Professional Baseball: A Call for Increased Validation and Consistency

BACKGROUND

Historically, treatment efficacy of professional baseball injuries has been determined by assessing the return-to-play (RTP) rate or using patient-reported functional outcomes scores; however, these methods may not be sensitive and specific enough for elite athletes. As a consequence, performance-based statistics are increasingly being reported in the medical literature.

PURPOSE

To (1) assess how treatment efficacy is currently reported in professional baseball players; (2) examine the variability in the reporting of these measures in terms of frequency, length of time followed, and units of measure; and (3) identify any attempts to validate these performance-based statistics.

STUDY DESIGN

Systematic review.

METHODS

All studies reporting treatment efficacy in professional baseball in PubMed, Embase, and Cochrane were identified. Data collected included frequency and method of reporting: RTP, functional outcomes, and performance-based statistics.

RESULTS

Fifty-four studies met all inclusion criteria. Of these, 51 (94%) reported RTP, 12 (22%) utilized functional outcomes, and 18 (33%) provided baseball-specific performance-based statistics to assess treatment efficacy. Great variability was seen in how follow-up was defined (games, seasons, months), duration of follow-up, and which performance-based statistics were utilized. None of the studies validated these performance-based statistics, determined minimal time of follow-up needed, or assessed the baseline variability in these statistics among noninjured players.

CONCLUSION

Most studies reported RTP to determine treatment efficacy, but significant variability was seen in how players were followed. Similarly, great variability was noted in the type and number of performance-based statistics utilized. Additional studies are necessary to validate these measures and determine the appropriate length of time that they should be followed.

CLINICAL RELEVANCE

This study provides a clear overview of the current methods that are used to determine treatment efficacy in professional baseball players.

[Ulnar collateral ligament reconstruction of the elbow in posttraumatic and chronic ligament instability]

OBJECTIVE

Restoration of ulnar elbow stability in cases of posttraumatic and chronic ulnar ligament instability.

INDICATIONS

Symptomatic therapy-resistant ulnar ligament instability of the elbow.

CONTRAINDICATIONS

Arthrofibrosis and high-grade elbow arthrosis.

SURGICAL TECHNIQUE

Anatomical reconstruction of the ulnar collateral ligament (UCL) with autologous tendon graft (tendons of the palmaris longus muscle and gracilis muscle) in implant-free docking technique.

POSTOPERATIVE MANAGEMENT

A cast for 1 week, then 5 weeks orthesis with limitation of complete extension and flexion; full weight bearing after 3 months.

RESULTS

After 2 years 90% of the patients are able to return at an equal level of activity. The overall complication rate is 10.4%. The most common complication is ulnar nerve neurapraxia in 7.8% of the patients.

Are the hamstrings from the drive leg or landing leg more active in baseball pitchers? An electromyographic study

BACKGROUND

Ulnar collateral ligament reconstruction (UCLR) has become a common procedure among baseball players of all levels. There are several graft choices in performing UCLR, one of which is a hamstring (gracilis or semitendinosus) autograft. It is unclear whether the hamstring muscle from a pitcher's drive leg (ipsilateral side of the UCLR) or landing leg (contralateral side of the UCLR) is more active during the pitching motion. We hypothesized that the landing leg semitendinosus will be more electromyographically active than the drive leg.

METHODS

Healthy, elite male pitchers aged 16-21 years were recruited. Sixteen pitchers (average age, 17.6 ± 1.6 years; 67% threw right handed) underwent electromyographic analysis. Pitchers threw 5 fastballs at 100% effort from the wind-up with electromyographic analysis of every pitch. Activation of the semitendinosus and biceps femoris in both legs was compared within pitchers and between pitchers.

RESULTS

Hamstring activity was higher in the drive leg than in the landing leg during each phase and in sum, although the difference was significant only during the double support phase (P = .021). On within-pitcher analysis, 10 of 16 pitchers had significantly more sum hamstring activity in the drive leg than in the landing leg, while only 4 of 16 had more activity in the landing leg (P = .043).

CONCLUSION

During the baseball pitch, muscle activity of the semitendinosus was higher in the drive leg than in the landing leg in most pitchers. Surgeons performing UCLR using hamstring autograft should consider harvesting the graft from the pitcher's landing leg to minimize disruption to the athlete's pitching motion.

Trends in Sports-Related Elbow Ulnar Collateral Ligament Injuries

BACKGROUND

Elbow ulnar collateral ligament (UCL) injuries are common, particularly in adolescent athletes playing overhead sports. While the incidence and outcomes of surgical UCL injuries are well documented, the nonsurgical UCL injury patterns and injury management in this population are not yet known.

PURPOSE/HYPOTHESIS

The purpose of this study was to retrospectively assess the injury severity and subsequent management of UCL injuries among competitive athletes aged 11 to 22 years. We hypothesized that nonsurgical UCL injuries would occur more frequently in younger athletes compared with older athletes.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Electronic medical records (using International Classification of Diseases, 9th Revision and 10th Revision and Current Procedural Terminology codes) and keyword searches were used to identify all patients with sports-related UCL injuries between January 2000 and April 2016. A total of 136 records were included. Patients were stratified into 3 age brackets (age 11-13 years, n = 17; age 14-16 years, n = 49; age 17-22 years, n = 70). There were no prior elbow surgical interventions. The main outcome measures included the frequency and severity of UCL injuries and injury management (surgical, nonsurgical). Independent variables included age, UCL injuries per year, and sport classification.

RESULTS

There were 53 surgical and 83 nonsurgical UCL injuries. The number of nonsurgical cases increased 9-fold from 2000-2008 to 2009-2016. The UCL injuries were distributed as follows: 60 sprains, 39 partial tears, 36 ruptures, and 1 rerupture. Moreover, 7% of sprains, 51% of partial tears, and 78% of ruptures underwent UCL reconstruction. Nonsurgical management was most common in the youngest athletes (age 11-13 years, 100.0% of total injuries; age 14-16 years, 71.4% of total injuries; and age 17-22 years, 44.3% of total injuries) (P = .007). UCL injury volume was most commonly associated with javelin (odds ratio, 6.69; 95% CI, 0.72-61.62; P = .07) and baseball (odds ratio, 1.55; 95% CI, 0.69-3.51; P = .32).

CONCLUSION

Younger athletes sustained less severe UCL injuries more often than older athletes. Participation in javelin and baseball was associated with a greater likelihood of UCL injuries based on our dataset. This is the first study to provide data on the volume of nonsurgical UCL injuries among athletes in various sports.

[Chronic ligamentous instability of the elbow]

BACKGROUND

Chronic ligamentous instability of the elbow is an important pathology as it is accompanied with pronounced dysfunction. Moreover, it represents an established risk factor for the development of osteoarthritis. Posterolateral rotatory instability (PLRI) caused by insufficiency of the lateral collateral ligament (LCL) is the most common type of chronic elbow instability and is usually a sequel of traumatic elbow dislocation. Chronic overload can lead to insufficiency of the ulnar collateral ligament (UCL) with subsequent valgus instability, especially in overhead athletes.

DIAGNOSTICS

Subjective instability and recurrent elbow dislocations are not always the main symptoms but elbow instability is instead often characterized by pain and secondary joint stiffness. Many clinical tests are available yet eliciting them can be difficult and inconclusive. A "drop sign" on lateral radiographs as well as the detection of collateral ligament injuries and joint incongruity on MRI scans can support the suspected diagnosis. In some cases, instability can only be verified by diagnostic arthroscopy.

TREATMENT

Reconstruction of the lateral ulnar collateral ligament (LUCL) for treatment of PLRI generally leads to good clinical results, yet recurrent instability remains an issue and has been reported in 8 % of cases. UCL reconstruction for chronic valgus instability leads to a return-to-sports rate of about 86 % in the overhead athlete. Ulnar neuropathy, which is seen in approximately 6 % of patients, represents the most common complication. On the rare occasion of multidirectional instability, the box-loop technique can be used for simultaneous reconstruction of the LUCL and UCL with a circumferential graft. 15 cases with promising results have been reported in literature thus far.

The Relationships Between Surface Measurements and Underlying Tendon Autograft Length for Upper Extremity Reconstructive Surgery

PURPOSE

The availability of tendon grafts is an important consideration for successful upper extremity reconstructive surgery, including flexor or extensor tendon reconstructions, tendon transfers, and ligament reconstructions. Graft selection is based on availability, expendability, ease of harvest, and length. Given variations in patient height and extremity length, existing average values may provide suboptimal insight into actual tendon lengths available. The purpose of this study is, therefore, to pursue a method of estimating available donor tendon lengths based on easily measured anatomical surface landmarks.

METHODS

Thirty cadaveric upper and lower extremity limbs were dissected and the length of commonly harvested tendon grafts including the palmaris longus, extensor indicis proprius, extensor digiti minimi, plantaris, and second long toe extensor was measured. Surface forearm length (from finger tip to cubital fossa) and surface fibular length (from lateral malleolus to fibular head) were also measured. Correlations between surface measurements and underlying tendon lengths were analyzed, and linear models were generated that predicted tendon length as a function of surface measurements.

RESULTS

Surface measurements were correlated with underlying tendon length (R = 0.46 - 0.66). Linear models could predict tendon lengths based on surface measurements. A ratio of donor tendon length compared with the limb segment measured was established for each tendon and can be applied to estimate donor tendon length. For the upper extremity tendons, the multipliers for the palmaris longus, extensor indicis proprius, and extensor digiti minimi were 0.51, 0.20, and 0.18, respectively. Lower extremity tendon ratios for the plantaris and extensor digitorum longus were 0.69 and 0.60, respectively.

CONCLUSIONS

Although length of available donor tendon can be a limiting variable at the time of surgery, surgeons may be better able to estimate underlying tendon lengths using easily obtained superficial measurements.

CLINICAL RELEVANCE

Information obtained from these cadaveric measurements may aid in preoperative planning in hand and upper extremity surgery.

Do Major League Baseball Team Physicians Harvest the Semitendinosus From the Drive Leg or Landing Leg When Performing Ulnar Collateral Ligament Reconstruction on Elite Baseball Pitchers?

Background:

Hamstring autograft is a common graft choice when performing ulnar collateral ligament reconstruction (UCLR).

Purpose/Hypothesis:

The purpose of this study was to survey Major League Baseball (MLB) team physicians and determine whether these physicians harvest the hamstring (semitendinosus or gracilis) from the drive leg (ipsilateral to surgical site) or landing leg (contralateral to surgical site) when performing UCLR on elite-level pitchers. The hypothesis was that the majority of surgeons harvest the hamstring from the drive leg when performing a UCLR.

Study Design:

Descriptive epidemiology study.

Methods:

Overall, 52 MLB team orthopaedic surgeons were sent the 5-question online survey. The survey assessed surgeon UCLR volume, surgical technique, which leg the hamstring graft was harvested from, the reasoning for choosing that particular leg, and whether the surgeon would change their practice if evidence showed the hamstring from one of the legs was more important than the other. The survey was sent out 5 separate times to maximize the response rate.

Results:

Forty (77%) MLB team physicians completed the survey. The largest number of surgeons (n = 16; 40%) performed between 5 and 14 UCLRs annually, while 6 (15%) performed more than 50 UCLRs annually. Most surgeons (n = 23; 57.5%) used the docking technique. Significantly more surgeons harvested the hamstring from the landing leg (n = 29; 72.5%) compared with the drive leg (n = 11; 27.5%) (P = .007). More surgeons cited the reason for their choice of leg as a belief that the hamstring they harvested plays less of a role in the ability of a pitcher to generate a forceful pitch (n = 25; 62.5%) than for logistical reasons in the operating room (n = 15; 37.5%); this difference was not statistically significant. Significantly more surgeons would change their practice (n = 35; 87.5%) if evidence showed the hamstrings from a specific (drive or landing) leg to be more active in the throwing motion compared with those who would not (P < .001).

Conclusion:

When performing a UCLR using hamstring autograft, the majority of MLB team physicians harvest the hamstring from the landing leg as opposed to the drive leg, as they believe the hamstring from the landing leg plays less of a role in generating a forceful pitch than that from the drive leg.

Magnetic Resonance Imaging Predictors of Failure in the Nonoperative Management of Ulnar Collateral Ligament Injuries in Professional Baseball Pitchers

BACKGROUND

A medial ulnar collateral ligament (UCL) injury of the elbow is an increasingly common injury in professional baseball pitchers. Predictors of success and failure are not well defined for the nonoperative management of these injuries.

PURPOSE

To evaluate the efficacy of objective measures to predict failure of the nonoperative management of UCL injuries.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Thirty-two professional pitchers (82%) met inclusion criteria and underwent an initial trial of nonoperative treatment for UCL tears based on clinical and radiological findings. Age, preseason physical examination results, magnetic resonance imaging (MRI) characteristics, and performance metrics were analyzed for these pitchers. Successful nonoperative management was defined as a return to the same level of play or higher for >1 year. Failure was defined as recurrent pain or weakness requiring a surgical intervention after a minimum of 3 months' rest when attempting a return to a throwing rehabilitation program.

RESULTS

Thirty-two pitchers (mean age, 22.3 years) who underwent initial nonoperative treatment of UCL injuries were evaluated. Thirty-four percent (11/32) failed and required subsequent ligament reconstruction. Sixty-six percent (21/32) successfully returned to the same level of play for 1 year without a surgical intervention. There was no significant difference seen in physical examination findings or performance metrics between these patients. When comparing MRI findings between the groups, 82% (9/11) ( P < .001) who failed nonoperative management had distal tears, and 81% (17/21) who did not fail had proximal tears ( P < .001). When adjusting for age, location, and evidence of chronic changes on MRI, the likelihood of failing nonoperative management was 12.40 times greater ( P = .020) with a distal tear. No other variable alone or in combination reached significance. When combining the parameters of a high-grade tear and distal location, 88% (7/8) failed nonoperative management.

CONCLUSION

In professional pitchers, distal UCL tears showed significantly higher odds of failure with nonoperative management compared with proximal tears. Thus, tear location should be considered when deciding between operative and nonoperative management.

Length of time between surgery and return to sport after ulnar collateral ligament reconstruction in Major League Baseball pitchers does not predict need for revision surgery

HYPOTHESIS

Pitchers who return to sport (RTS) sooner will have a higher risk of revision ulnar collateral ligament reconstruction (UCLR) than those who return later.

METHODS

All professional (major and minor league) baseball pitchers who underwent UCLR between 1974 and 2016 were identified. Date of the index UCLR was recorded. The date of the first game back at any professional level after surgery and the date the pitcher returned to the same level of play (if applicable) were recorded. Length of time between these dates was compared for pitchers who required a revision UCLR and those who did not.

RESULTS

Overall, 569 pitchers (average age, 24.8 ± 4.1 years) underwent UCLR and had reliable game logs after surgery. No statistically significant difference existed in the length of time to RTS at any professional level or at the same professional level between those pitchers who did not require a revision UCLR and those who did (P = .442, P = .238). Pitchers who required revision UCLR returned to any level of play almost 2 months earlier (14.7 vs. 16.5 months) and returned to the same level of play >2 months earlier (15.2 vs. 17.7 months) than matched controls who did not require revision UCLR, although this was not statistically significant (P = .179, P = .204).

CONCLUSION

No statistically significant difference existed in the length of time to RTS after UCLR in professional baseball players who required a revision UCLR and those who did not.

Treatment of Ulnar Collateral Ligament Tears of the Elbow: Is Repair a Viable Option?

BACKGROUND

Ulnar collateral ligament (UCL) tears have become common, and UCL reconstruction (UCLR) is currently the preferred surgical treatment method for treating UCL tears.

PURPOSE/HYPOTHESIS

The purpose of this study was to review the literature surrounding UCL repair and determine the viability of new repair techniques for treatment of UCL tears. We hypothesized that UCL repair techniques will provide comparable results to UCLR for treatment of UCL tears.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A systematic review was registered with PROSPERO and performed with PRISMA guidelines using 3 publicly available free databases. Biomechanical and clinical outcome investigations reporting on UCL repair with levels of evidence 1 through 4 were eligible for inclusion. Descriptive statistics were calculated for each study and parameter/variable analyzed.

RESULTS

Of the 46 studies eligible, 4 studies (3 clinical and 1 biomechanical) were included. There were 92 patients (n = 92 elbows; 61 males [62.3%]; mean age, 21.9 ± 4.7 years) included in the clinical studies, with a mean follow-up of 49 ± 14.4 months. Eighty-six percent of repairs performed were on the dominant elbow, and 38% were in college athletes. Most UCL repairs (66.3%) were performed via suture anchors. After UCL repair, 87.0% of patients were able to return to sport. Overall, 94.9% of patients scored excellent/good on the Andrews-Carson score. Patients who were able to return to sport after UCL repair did so within 6 months after surgery. Biomechanically, when UCL repair was compared with the modified Jobe technique, the repair group showed significantly less gap formation than the reconstruction group.

CONCLUSION

In patients for whom repair is properly indicated, UCL repair provides similar return-to-sport rates and clinical outcomes with shorter return-to-sport timing after repair compared with UCL reconstruction. Future outcome studies evaluating UCL repair with internal bracing are necessary before recommending this technique.

Biomechanical testing of the reconstructed ulnar collateral ligament: a systematic review of the literature

PURPOSE

The purpose was to perform a systematic review of the literature investigating biomechanical studies of ulnar collateral ligament reconstruction (UCLR) techniques to summarize the most commonly analyzed methods of fixation (at both the ulna and humerus), the degree of elbow flexion at the time of fixation, graft characteristics, and modes of failure with these techniques.

MATERIALS AND METHODS

A systematic review was performed. All cadaveric biomechanical studies that tested a reconstruction method for UCLR were included. Descriptive statistics were calculated for each study and parameter/variable analyzed.

RESULTS

Twenty-three studies were included with a total of 397 elbows in 242 cadavers (mean age 54.8 ± 20 years, range 16-96). The majority of studies (65 %) used a palmaris longus graft. The docking technique (37.2 %) was the most commonly tested reconstruction method. Significant heterogeneity between studies precluded assimilation of specific techniques (each of the 23 studies utilized a unique technique). Fixation was performed at 30°-90° of elbow flexion. The most common mode of failure was suture failure (51 %), followed by midsubstance rupture (27.00 %), and bone tunnel fracture (14.00 %). No significant differences were observed amongst techniques for all measures analyzed.

CONCLUSION

This study found the docking technique to be the most commonly tested technique, while the mode of reconstruction failure was most commonly at the suture interface. If the graft failed at the bone interface, it was most likely to occur at the ulna. Surgeon preference and comfort level with a specific technique should dictate choice.

Medial ulnar collateral ligament reconstruction of the elbow in major league baseball players: Where do we stand?

The ulnar collateral ligament (UCL) is a vital structure to the overhead athlete, especially the baseball pitcher. For reasons not completely understood, UCL injuries have become increasingly more common in major league baseball (MLB) pitchers over the past 10 years. UCL reconstruction (UCLR) is the current gold standard of treatment for these injuries in MLB pitchers who wish to return to sport (RTS) at a high level and who have failed a course of non-operative treatment. Results following UCLR in MLB pitchers have been encouraging, with multiple RTS rates now cited at greater than 80%. Unfortunately, with the rising number of UCLR, there has also been a spike in the number of revision UCLR in MLB pitchers. Similar to primary UCLR, the etiology of the increase in revision UCLR, aside from an increase in the number of pitchers who have undergone a primary UCLR, remains elusive. The current literature has attempted to address several questions including those surrounding surgical technique (method of exposure, graft choice, management of the ulnar nerve, concomitant elbow arthroscopy, etc.), post-operative rehabilitation strategies, and timing of RTS following UCLR. While some questions have been answered, many remain unknown. The literature surrounding UCLR in MLB pitchers will be reviewed, and future directions regarding this injury in these high level athletes will be discussed.

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.