Clinical Utility of an MRI-Based Classification System for Operative Versus Nonoperative Management of Ulnar Collateral Ligament Tears: A 2-Year Follow-up Study

Early Surgery for Partial Tears of the Ulnar Collateral Ligament May Be More Cost-Effective and Result in Longer Playing Careers Than Nonoperative Management for High-Level Baseball Pitchers: A Decision-Analytic Markov Model-Based Analysis

BACKGROUND

Nonoperative management versus early reconstruction for partial tears of the medial ulnar collateral ligament (MUCL) remains controversial, with the most common treatment options for partial tears consisting of rest, rehabilitation, platelet-rich plasma (PRP), and/or surgical intervention. However, whether the improved outcomes reported for treatments such as MUCL reconstruction (UCLR) or nonoperative management with a series of PRP injections justifies their increased upfront costs remains unknown.

PURPOSE

To compare the cost-effectiveness of an initial trial of physical therapy alone, an initial trial of physical therapy plus a series of PRP injections, and early UCLR to determine the preferred cost-effective treatment strategy for young, high-level baseball pitchers with partial tears of the MUCL and with aspirations to continue play at the next level (ie, collegiate and/or professional).

STUDY DESIGN

Economic and decision analysis; Level of evidence, 2.

METHODS

A Markov chain Monte Carlo probabilistic model was developed to evaluate the outcomes and costs of 1000 young, high-level, simulated pitchers undergoing nonoperative management with and without PRP versus early UCLR for partial MUCL tears. Utility values, return to play rates, and transition probabilities were derived from the published literature. Costs were determined based on the typical patient undergoing each treatment strategy at the authors' institution. Outcome measures included costs, acquired playing years (PYs), and the incremental cost-effectiveness ratio (ICER).

RESULTS

The mean total costs resulting from nonoperative management without PRP, nonoperative management with PRP, and early UCLR were $22,520, $24,800, and $43,992, respectively. On average, early UCLR produced an additional 4.0 PYs over the 10-year time horizon relative to nonoperative management, resulting in an ICER of $5395/PY, which falls well below the $50,000 willingness-to-pay threshold. Overall, early UCLR was determined to be the preferred cost-effective strategy in 77.5% of pitchers included in the microsimulation model, with nonoperative management with PRP determined to be the preferred strategy in 15% of pitchers and nonoperative management alone in 7.5% of pitchers.

CONCLUSION

Despite increased upfront costs, UCLR is a more cost-effective treatment option for partial tears of the MUCL than an initial trial of nonoperative management for most high-level baseball pitchers.

Rehabilitation Protocols in Elbow Medial Ulnar Collateral Ligament Injuries: A Systematic Review of Articles Published in the Last 20 Years

CONTEXT

Elbow medial ulnar collateral ligament (UCL) injuries have become increasingly common in athletes. Despite this, rehabilitation protocols appear to vary drastically, which may explain the clinical equipoise regarding optimal management.

OBJECTIVE

This systematic review reports rehabilitation characteristics reported after UCL injuries and compares reported outcomes based on early versus delayed rehabilitation.

DATA SOURCES

Our search utilized PubMed/MEDLINE, Embase, Web of Science, and Cochrane to identify all articles on UCL rehabilitation published between January 1, 2002 and October 1, 2022.

STUDY SELECTION

Studies in English with ≥5 patients that reported rehabilitation protocols for UCL injuries were evaluated.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Data included sample characteristics, time to achieve physical therapy milestones, outcome scores, and return-to-play (RTP) rate and timing.

RESULTS

Our review included 105 articles with a total of 15,928 elbows (98% male; weighted mean age, 23 years; follow-up, 47 months), with 15,077 treated operatively and 851 treated nonoperatively. The weighted mean time patients spent adhering to nonweightbearing status was 42 days. The mean time until patients were given clearance for active range of motion (ROM) 15 days, full ROM 40 days, and elbow strengthening exercises 32 days. The mean time until all restrictions were lifted was 309 days. The mean time to begin a throwing program was 120 days. Across all rehabilitation characteristics, protocols for patients undergoing nonoperative management started patients on rehabilitation earlier. After UCL reconstruction, earlier active ROM (≤14 days), elbow strengthening (≤30 days), no restrictions (≤180 days), and throwing (≤120 days) postoperatively led to earlier RTP without a negative effect on functional outcome scores.

CONCLUSION

Current literature provides a spectrum of protocols for elbow UCL rehabilitation, regardless of management. Nonoperative patients began ROM activities, strengthening, and throwing programs sooner than operative patients, and earlier milestones led to earlier RTP.

Return to Sport After Ulnar Collateral Ligament Tears Treated with Platelet-Rich Plasma Injections is Influenced by Length of Rehabilitation and Leukocyte Content of Injections: A Systematic Review

PURPOSE

To analyze the current literature assessing return to sport (RTS) outcomes after platelet-rich plasma (PRP) injections for the nonoperative treatment of ulnar collateral ligament (UCL) injuries.

METHODS

A systematic review of PubMed, Embase, and Web of Science databases was conducted in June 2023 to identify studies assessing RTS after PRP injections for UCL injuries. Tear severity, leukocyte content of PRP, rehabilitation protocol, and RTS outcomes were collected. Heterogeneity was assessed through proportional random-effects models for RTS and return to preinjury level of play (RTLP) with subgroup analysis by rehabilitation length, leukocyte content of PRP, and tear severity.

RESULTS

Eight studies with 278 partial-thickness and 44 full-thickness tears were identified. The mean age of patients ranged from 17.3 to 26 years. The mean RTS time after injection ranged from 5.2 to 25.4 weeks. High heterogeneity was observed among studies, with RTS rates ranging from 46% to 100% (I2 = 83%) and RTLP rates ranging from 34% to 100% (I2 = 83%). Studies with the longest rehabilitation programs (12-14 weeks) had RTS rates of 87% to 100% (I2 = 0%). RTS rates among athletes treated with leukocyte-poor and leukocyte-rich PRP ranged from 73% to 100% (I2 = 30%) and 52% to 88% (I2 = 84%), respectively. Subanalysis of RTS by tear severity demonstrated high variability, with partial-thickness rates ranging from 59% to 100% (I2 = 55%) and full-thickness rates ranging from 27% to 100% (I2 = 63.2%).

CONCLUSIONS

Studies assessing RTS after PRP injections are highly heterogeneous; however, current data suggest nonoperative RTS and RTLP rates ranging from 46% to 100% and 34% to 100%, respectively. Studies with at least 12 weeks of rehabilitation and studies using leukocyte-poor PRP demonstrated low heterogeneity and greater RTS rates. Alternatively, high heterogeneity was observed among both partial- and full-thickness tears.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III-IV studies.

Return to Sport After Nonoperative Management of Elbow Ulnar Collateral Ligament Injuries: A Systematic Review and Meta-analysis

BACKGROUND

Elbow ulnar collateral ligament (UCL) injuries can result in significant functional impairment in throwing and overhead athletes. UCL reconstruction and repair are proven treatments to restore stability, but the efficacy of nonoperative management is unclear.

PURPOSE

To determine the rate of return to sports (RTS) and return to previous level of play (RTLP) in athletes sustaining medial elbow ulnar collateral ligament (UCL) injuries treated nonoperatively.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A literature search was performed using Scopus, PubMed, Medline, the Cochrane Database for Systematic Review, and the Cochrane Central Register for Controlled Trials according to the 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Inclusion criteria were limited to level 1 to 4 human studies reporting on RTS outcomes after nonoperative management of UCL injuries.

RESULTS

A total of 15 studies, consisting of 365 patients with a mean age of 20.45 ± 3.26 years, were identified. Treatment primarily consisted of platelet-rich plasma (PRP) injections with physical therapy (n = 189 patients; n = 7 studies) versus physical therapy alone (n = 176 patients; n = 8 studies). The overall RTS rate was 79.7% and the overall RTLP rate was 77.9%. Increasing UCL injury severity grade was associated with lower RTS rates. The RTS rate for proximal tears (89.7%; n = 61/68) was significantly greater than that for distal tears (41.2%; n = 14/34) (P < .0001). No significant difference in RTS rate was seen in patients treated with PRP versus those who did not receive PRP (P = .757).

CONCLUSION

For athletes undergoing nonoperative management of UCL injuries, the overall RTS and RTLP rates were 79.7% and 77.9%, respectively, with excellent outcomes in grade 1 and grade 2 UCL injuries, specifically. The RTS rate for proximal tears was significantly higher than that for distal tears. Athletes were most commonly treated with PRP injection and physical therapy.

In Vivo Effect of Partial Ulnar Collateral Ligament Tear Location on Ulnohumeral Joint Gapping With Stress Ultrasound in Baseball Pitchers

BACKGROUND

Stress ultrasonography (SUS) has provided clinicians with an alternative means of evaluating ulnar collateral ligament (UCL) injury by dynamically assessing ulnohumeral joint space gapping under applied valgus stress. However, 3 previous cadaveric studies have evaluated the biomechanical effect of partial UCL tears at different anatomic locations with conflicting results.

PURPOSE/HYPOTHESIS

The purpose of this study was to use in vivo data from patients with magnetic resonance (MR)-confirmed partial UCL tears to determine if anatomic partial tear location influenced the resultant stability of the elbow in terms of ulnohumeral joint gapping on SUS. It was hypothesized that no difference would be seen in the amount of ulnohumeral joint gapping based on MR-identified anatomic partial UCL tear location.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All patients diagnosed with elbow injury from 2015 to 2020 were screened to identify competitive baseball pitchers with a partial UCL tear who received an SUS. Partial UCL tear was diagnosed via surgeon and radiologist interpretation of elbow MR imaging (MRI) as well as confirmation at the time of surgery as documented in the operative report. Demographic, injury, and treatment data were collected from the clinic notes, MRI reports, and stress ultrasound reports. Ulnohumeral joint gapping on SUS was calculated as the difference between ulnohumeral joint gapping without valgus stress versus ulnohumeral joint gapping with valgus stress (delta) as performed by a musculoskeletal radiologist.

RESULTS

Overall, 60 male baseball pitchers (age, 19.2 ± 2.1 years), including 22 (37%) high school, 26 (43%) collegiate, and 12 (20%) professional pitchers, were evaluated. Regarding the location of partial UCL tears, 32 (53%) pitchers had proximal tears and 28 (47%) had distal tears. The mean delta value cohort was 2.1 ± 1.1 mm, and 34 pitchers (57%) had delta values >2.0 mm. Ulnohumeral joint gapping (high school [1.9 mm] vs collegiate [2.6 mm] vs professional [1.6 mm]; P = .004) and the percentage of pitchers with delta values >2.0 mm (45% vs 77% vs 33%; P = .017) differed based on level of competition. After controlling for age, body mass index, and level of competition in a multivariate linear regression, tear location was not related to ulnohumeral joint gapping (P = .499).

CONCLUSION

No difference was observed in the amount of ulnohumeral joint gapping on SUS in symptomatic baseball pitchers with MR-identified partial UCL tears at differing anatomic locations. The findings of this study are contrary to previous cadaveric studies that have evaluated the effects of UCL tear characteristics on delta laxity.

Ulnar Collateral Ligament Tears: A Modified Consensus Statement

PURPOSE

The purpose of this study was to establish consensus statements on the treatment of UCL injuries and to investigate whether consensus on these distinct topics could be reached.

METHODS

A modified consensus technique was conducted among twenty-six elbow surgeons and 3 physical therapists/athletic trainers. Strong consensus was defined as 90-99% agreement.

RESULTS

Of the 19 total questions and consensus statements 4 achieved unanimous consensus, 13 achieved strong consensus, and 2 did not achieve consensus.

CONCLUSION

There was unanimous agreement that the risk factors include overuse, high velocity, poor mechanics, and prior injury. There was unanimous agreement that advanced imaging in the form of either an MRI or MRA should be performed in a patient presenting with suspected/known UCL tear that plans to continue to play an overhead sport, or if the imaging study could change the management of the patient. There was unanimous agreement regarding lack of evidence for the use of orthobiologics in the treatment of UCL tears as well as the areas pitchers should focus on when attempting a course of non-operative management. The statements that reached unanimous agreement for operative management were regarding operative indications and contraindications for UCL tears, prognostic factors that should be taken into consideration in when performing UCL surgery, how to deal with the flexor-pronator mass during UCL surgery and use of an internal brace with UCL repairs. Statements that reached unanimous agreement for RTS were regarding: portions of the physical exam should be considered when determining whether to allow a player to RTS, unclear how velocity, accuracy, and spin rate should be factored into the decision of when players can RTS and sports psychology testing should be used to determine whether a player is ready to RTS.

LEVEL OF EVIDENCE

Expert opinion (Level V).

Does proximal versus distal injury location of the medial ulnar collateral ligament of the elbow differentially impact elbow stability? An ultrasound-guided and robot-assisted biomechanical study

BACKGROUND

The location (proximal vs. distal) of elbow medial ulnar collateral ligament (MUCL) tears impacts clinical outcomes of nonoperative treatment. The purposes of our study were to (1) determine whether selective releases of the MUCL could be performed under ultrasound (US) guidance without disrupting overlying soft tissues, (2) assess the difference in medial elbow stability for proximal and distal releases of the MUCL using stress US and a robotic testing device, and (3) elucidate the flexion angle that resulted in the greatest amount of medial elbow laxity after MUCL injury.

METHODS

Sixteen paired, fresh-frozen elbow specimens were used. Valgus laxity was evaluated with both US and robotic-assisted measurements before and after selective MUCL releases. A percutaneous US-guided technique was used to perform proximal MUCL releases in 8 elbows and to perform distal MUCL releases in their matched pairs. The robot was used to determine the elbow flexion angle at which the maximum valgus displacement occurred for both proximally and distally released specimens. Open dissection was then performed to assess the accuracy of the percutaneous releases.

RESULTS

Percutaneous US-guided releases were successfully performed in 15 of 16 specimens. The proximal release resulted in greater valgus angle displacement (11° ± 2°) than the distal release (8° ± 2°) between flexion angles of 30° and 70° (P < .0001 at 30°, P < .0001 at 40°, P = .001 at 50°, P = .005 at 60°, and P = .020 at 70°). Valgus displacement between release locations did not reach the level of statistical significance between 80° and 120° (P = .051 at 80°, P = .131 at 90°, P = .245 at 100°, P = .400 at 110°, and P = .532 at 120°). When we compared the values for the mean increase in US delta gap (stressed - supported state) from before to after MUCL release, the proximally released elbows had larger increases than the distally released elbows (5.0 mm proximal vs. 3.7 mm distal, P = .032). After MUCL release, maximum mean valgus displacement occurred at 49° of flexion.

CONCLUSIONS

US-guided selective releases of the MUCL can be performed reliably without violating the overlying musculature. Valgus instability is not of greater magnitude for distal releases when compared with proximal releases. This findings suggests there must be alternative factors to explain the difference in clinical prognosis between distal and proximal tears. The observed flexion angle for maximum valgus laxity could have important implications for elbow positioning during US or fluoroscopic stress examination, as well as surgical repair or reconstruction of the MUCL.

Sites of flexor-pronator muscle injury and relationship between ulnar collateral ligament injury and flexor-pronator muscle injury in baseball players: a retrospective cohort study

BACKGROUND

Ulnar collateral ligament (UCL) and flexor-pronator muscle (FPM) injuries are common in baseball players. However, the sites of FPM injuries and the relationship between UCL and FPM injuries in baseball players have not been fully clarified. The purpose of this study was to identify the sites of FPM injuries and to determine the relationships of location and severity of UCL injury with the presence of FPM injuries in baseball players.

METHODS

UCL and FPM injuries were diagnosed using magnetic resonance imaging in 99 baseball players. The sites of FPM injuries were identified on coronal, sagittal, and axial images. UCL injury severity was classified into four grades: chronic changes, low-grade partial tear, high-grade partial tear, and complete tear. UCL injury location was classified as proximal UCL tear or distal UCL tear. All images were assessed by a musculoskeletal radiologist and an orthopedic surgeon.

RESULTS

Combined UCL and FPM injuries were observed in 45 of 99 players, of which 40 of 45 (89%) involved injury of the flexor digitorum superficialis (FDS). All FDS injuries were in the deep layer of the muscle belly. There was no significant difference between the severity of UCL injury and presence of FPM injuries (P = .352). There was a significant association of distal UCL tears with FPM injuries (P < .001).

CONCLUSION

FDS injury occurs most commonly in the muscle belly of the second and fifth digits. There may be no relationship between the severity of UCL injury and presence of FPM injury in baseball players. FPM injuries may be a contributing factor in the failure of nonoperative management of distal UCL tears in baseball players.

Elbow Ulnar Collateral Ligament Injuries in Overhead Athletes: An Infographic Summary

Ulnar collateral ligament (UCL) injuries of the elbow are common in throwing athletes. Given that the UCL's primary function is to provide valgus stability during the deceleration phase of throwing, injury to the UCL will render throwing difficult to nearly impossible.¹⁵ Injuries will occur more so in the sports of baseball, softball, and javlineers participating in track and field.^5,10,14 Data has indicated that valgus torque reaches 64 N-m and proximal forces as high as 1000 N to prevent elbow distraction. Further, angular velocity across elbow may reach 1900-2480 degrees/second.^6,8 Imaging modalities that have the greatest accuracy for diagnosis include magnetic resonance imaging (MRI), MRI-arthrogram, and stress ultrasonography.^2,3,11,12 Treatment of UCL injury depends on multiple factors. These include if the injury is a partial tear or complete tear and the location (distal versus proximal) of the partial tear.⁷ Further, complete tears, as well as partial distal tears, are more likely to undergo surgical intervention.^1,13 Treatment decision-making is primarily dependent on following factors: location, severity, if the patient is a throwing athlete, and if the patient is in his or her last year of his/her throwing career due to the length of the rehabilitation process if surgery is pursued.¹⁵ Return-to-play success rates when treated conservatively vary from anywhere from 42% to 100%. Conservative treatment includes rest, rehabilitation, platelet-rich plasma injections, and a throwing program.⁴ Surgical treatment has evolved significantly with various reconstructive techniques and (when indicated) surgical repair with internal bracing. Return-to-play rates are high, ranging from 80% to 95% with low complication rates, but rehabilitation for reconstruction can range from 12-18 months or longer. Therefore, patients must be made aware of the commitment to the rehabilitation process if electing to undergo surgical reconstruction.⁹.

Return-to-play outcomes in high school baseball players after ulnar collateral ligament injuries: dynamic contributions of flexor digitorum superficialis function

BACKGROUND

Ulnar collateral ligament (UCL) injuries are common in baseball pitchers. The purpose of this study was to evaluate changes to medial elbow joint laxity under valgus stress, as well as under valgus stress with flexor digitorum superficialis (FDS) contraction, and its ability to predict rehabilitation outcomes.

METHODS

Sixty-one UCL injuries were diagnosed. All patients were high school students who initially received rehabilitation treatment. Rates of return to play and return to the same level of play or higher (RTSP) were calculated and correlated with joint gapping under the following conditions: elbow gravity valgus stress and intra-articular ring-down artifact (RDA) at rest, elbow gravity valgus stress, and elbow gravity valgus stress with maximum FDS contraction.

RESULTS

The overall RTSP rate in patients receiving nonoperative treatment was 83.6% (51 of 61 patients). The RDA at rest significantly differed between the RTSP and non-RTSP groups, with an odds ratio of 17.5. This result indicated that the RDA could be a predictor of rehabilitation outcomes. Moreover, there were significant differences in the RDA under gravity valgus stress conditions with FDS contraction between the 2 groups, with an odds ratio of 98.0. Multivariate logistic regression analysis identified 1 variable (RDA under valgus stress with FDS contraction) as the most significant predictive factor for successful treatment of UCL elbow injury.

CONCLUSIONS

UCL injuries in high school baseball players can be successfully treated nonoperatively in most cases. Stress ultrasound with FDS muscle contraction can help predict the potential for RTSP.

Medial Elbow Instability Resulting From Partial Tears of the Ulnar Collateral Ligament: Stress Ultrasound in a Cadaveric Model

BACKGROUND

There is consensus that most complete ulnar collateral ligament (UCL) injuries in throwers would benefit from surgical intervention. Optimal treatment for partial UCL tears remains controversial. Stress ultrasonography has become a well-accepted diagnostic modality for assessing UCL injury.

HYPOTHESIS

Partial UCL tears will result in an intermediate increase in ulnohumeral joint space gapping as compared with that of an intact UCL and a complete UCL tear, but the degree of joint space gapping will vary by anatomic location of the partial tear.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-one cadaveric elbows were divided into 7 groups representing different anatomic locations of UCL partial tears. Partial tears were simulated by cutting 50% of the measured width of the UCL at 6 locations: distal anterior/posterior, midsubstance anterior/posterior, and proximal anterior/posterior. A seventh partial tear was created by partially elevating the undersurface of the distal UCL to simulate the radiographic "T-sign." Valgus stress (15 daN) was applied to each cadaveric elbow at 30° of flexion using a standardized device. Each specimen was tested intact, partially torn, and completely torn. At each state, joint space was measured using stress ultrasonography, and the difference in joint space from unstressed to stressed (delta) was recorded.

RESULTS

There were 10 right and 11 left upper extremity specimens. The mean delta was 0.58 mm for the intact state and <0.75 mm in all groups. Both distal partial tear groups had mean deltas <0.75 mm, similar to intact elbows. Proximal tears and the T-sign demonstrated intermediate deltas (0.99-1.23 mm). Midsubstance partial tears demonstrated the largest deltas (1.57-2.03 mm), similar to those of the complete tears. All complete tear groups had a mean delta >1.5 mm (1.54-3.03 mm).

CONCLUSION

These findings suggest that partial tears introduce a spectrum of instability from functionally intact to completely torn. As a result, some may be biomechanically amenable to nonoperative treatment, while others would be indicated for early reconstruction. Further research into the biological and biomechanical determinants of nonoperative treatment failure will assist with more precise treatment recommendations.

CLINICAL RELEVANCE

Describing the biomechanical consequences of different, clinically significant partial UCL tears potentially allows more precise recommendations for operative and nonoperative treatment.

Ulnar Collateral Ligament Tear Location May Affect Return-to-Sports Rate but Not Performance Upon Return to Sports After Ulnar Collateral Ligament Reconstruction Surgery in Professional Baseball Players

BACKGROUND

The number of ulnar collateral ligament (UCL) tears in professional baseball players is increasing. UCL reconstruction (UCLR) is the treatment of choice in players with failed nonoperative treatment who wish to return to sports (RTS). It is unknown if UCL tear location influences the ability of players to RTS or affects their performance upon RTS.

PURPOSE/HYPOTHESIS

The purpose was to compare the RTS rate and performance upon RTS in professional baseball players who underwent UCLR based on UCL tear location (proximal vs distal). It was hypothesized that no difference in RTS rate or performance upon RTS will exist between players with proximal or distal UCL tears.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All professional baseball players who underwent primary UCLR by a single surgeon between 2016 and 2018 were eligible for inclusion. Players with purely midsubstance tears or revision UCLR were excluded. Tear location was determined based on preoperative magnetic resonance imaging (MRI) and intraoperative findings. RTS rate and performance were compared between players with proximal versus distal UCL tears.

RESULTS

Overall, 25 pitchers (15 proximal and 10 distal tears) and 5 position players (2 proximal and 3 distal) underwent primary UCLR between 2016 and 2018. Of the 25 pitchers, 84% were able to RTS. Of the 5 position players, 80% were able to RTS. Among the total cohort of pitchers and position players, 12 out of 17 (71%) players with proximal tears were able to RTS, while of the 13 distal tears, 13 out of 13 (100%) players were able to RTS (P = .05). With regard to performance data, pitchers with distal tears had higher utilization postoperatively and, as such, allowed statistically more hits (P = .03), runs (P = .015), and walks (P = .021) postoperatively. However, the WHIP ([walks + hits]/innings pitched) was not different between players with proximal or distal tears, indicating that efficacy in games was not significantly different between groups.

CONCLUSION

Professional baseball players who sustain a distal UCL tear and undergo UCLR may be more likely to RTS than those who sustain a proximal UCL tear and undergo UCLR. Players with distal UCL tears who underwent UCLR saw higher utilization postoperatively than those with proximal UCL tears. Further work is needed in this area to confirm this result.