Prognostic utility of an magnetic resonance imaging-based classification for operative versus nonoperative management of ulnar collateral ligament tears: one-year follow-up

Shear wave elastography ultrasound does not quantify mechanical properties of the ulnar collateral ligament of the elbow

OBJECTIVE

To validate shear wave elastography (SWE) stiffness measurements for the ulnar collateral ligament (UCL) of the elbow compared to mechanical measurements.

MATERIALS AND METHODS

Eleven fresh frozen human cadaveric upper extremities were evaluated by a musculoskeletal-specialized radiologist to provide SWE measurements used to calculate stiffness at 4 points along the anterior band of the UCL at various load states and flexion angles. Specimens were then dissected and optical markers were placed on the UCL to track displacement during applied force by a load frame, thereby providing measurements to calculate the mechanical stiffness. These two stiffness values were compared by ANOVA for all load states and flexion angles.

RESULTS

Measurements of stiffness by SWE for the UCL were three orders of magnitude smaller than the true mechanical testing stiffness and no correlations between SWE and mechanical measurements of stiffness were found at 30, 60 or 90 degrees of elbow flexion (R2 = 0.004, p = 0.85; R2 = 0.001, p = 0.92; R2 = 0.15, p = 0.24 respectively). SWE stiffness was greatest near the insertion of the ligament and lowest in the mid-substance of the ligament (p = 0.0002).

CONCLUSIONS

SWE stiffness did not correlate with mechanical measurements. Clinical utility of musculoskeletal SWE may be better defined when biomechanical properties or clinical outcomes can be correlated with SWE measurements. The ultimate clinical utility of SWE in musculoskeletal tissues may be qualitative, as demonstrated by differences throughout the length of the UCL in this study.

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.

Reliability of ulnar collateral ligament findings in magnetic resonance imaging

BACKGROUND

Ulnar collateral ligament (UCL) tears are common in baseball players. Although magnetic resonance imaging (MRI) is the most used imaging modality for UCL injuries, the inter-rater reliability of MRI analyzing specific characteristics of UCL pathology has not been defined. The purpose of this study was to define the inter-rater reliability of MRI for evaluating UCL characteristics.

METHODS

Three surgeons analyzed 45 noncontrast MRIs: 15 without UCL tears, 15 with intraoperatively confirmed partial-thickness tears, and 15 with intraoperatively confirmed full-thickness tears. Findings evaluated included ligament characteristics (periligamentous or osseous edema, ligament hypertrophy, calcifications, and partial- or full-thickness tearing) and location of the pathology (proximal, midsubstance, or distal). Fleiss' κ coefficients were used to assess interobserver reliability.

RESULTS

There were high rates of agreement for midsubstance (κ: 0.50) and distal (κ: 0.69) ligament edema and proximal osseous edema (κ: 0.48). There were low rates of agreement for proximal ligament edema (κ: 0.08), ligament thickening (κ: -0.02 to 0.20), and proximal to midsubstance calcifications (κ: -0.04 to 0.10). Midsubstance (κ: 0.55) and distal full-thickness tears (κ: 0.63) demonstrated higher agreement than proximal (κ: 0.29). Proximal partial-thickness tears (κ: 0.45) had higher agreement than midsubstance (κ: -0.02) or distal (κ: -0.02).

CONCLUSIONS

In our study, there was high inter-rater reliability regarding proximal osseous edema, midsubstance, and distal ligament edema and full-thickness tears. There was no agreement for midsubstance and distal partial-thickness UCL tears, but fair agreement for proximal tears. UCL tissue characteristics including ligament thickening and calcifications demonstrated low agreement. Challenges remain in effectively evaluating UCL tissue characteristics on noncontrast MRIs.

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).

Psychological Factors Associated With Return to Play After Ulnar Collateral Ligament Reconstruction: A Systematic Review

Background

The role of psychological factors in return to play (RTP) after ulnar collateral ligament (UCL) reconstruction remains unclear.

Purpose

To perform a systematic review of the literature to (1) identify the specific psychological factors that affect RTP after UCL reconstruction and (2) determine the proportion of failures to RTP after UCL reconstruction because of psychological factors.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review of the literature following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was conducted. We queried the Cochrane Database of Systematic Reviews, Ovid/Embase, PubMed, and Web of Science databases to identify studies examining psychological factors and RTP after UCL reconstruction. Data pertaining to study characteristics and design, clinical and demographic characteristics, and psychological factors were collected. Patients were pooled across included studies, weighted means were calculated, and descriptive statistical analysis was performed.

Results

A total of 8 studies consisting of 378 patients were included for analysis. The mean time to RTP was 12.2 months, and the overall RTP rate was 89.4%. Psychological factors affecting RTP included loss of interest, fear of reinjury, individual personality traits, personal reasons, and psychological concerns. While clinical factors accounted for 46.2% (n = 24) of failures to RTP, psychological factors comprised 40.4% (n = 21) of the reasons for failure to RTP. The most commonly cited psychological factors affecting RTP were loss of interest (n = 15 [28.8%]) and fear of reinjury (n = 3 [5.8%]).

Conclusion

Psychological factors represented a substantial proportion of failures to RTP after UCL reconstruction, especially in adolescent athletes. Future prospective studies and multicenter initiatives are needed to more thoroughly evaluate the psychological concerns of patients before and after UCL reconstruction.

Rehabilitation and Return to Sport Criteria Following Ulnar Collateral Ligament Reconstruction: A Systematic Review

BACKGROUND

Ulnar collateral ligament (UCL) reconstruction (UCLR) is a viable treatment option for patients with UCL insufficiency, especially in the overhead throwing athlete. Within the clinical literature, there is still no universally agreed upon optimal rehabilitation protocol and timing for return to sport (RTS) after UCLR.

HYPOTHESIS

There will be significant heterogeneity with respect to RTS criteria after UCLR. Most surgeons will utilize time-based criteria rather than functional or performance-based criteria for RTS after UCLR.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

All level 1 to 4 studies that evaluated UCLR with a minimum 1-year follow-up were eligible for inclusion. Studies lacking explicit RTS criteria, studies that treated UCL injury nonoperatively or by UCL repair, or studies reporting revision UCLR were excluded. Each study was analyzed for methodologic quality, RTS, timeline of RTS, and RTS rate.

RESULTS

Overall, 1346 studies were identified, 33 of which met the inclusion criteria. These included 3480 athletes across 21 different sports. All studies reported RTS rates either as overall rates or via the Conway-Jobe scale. Timelines for RTS ranged from 6.5 to 16 months. Early bracing with progressive range of motion (ROM) (93.9%), strengthening (84.8%), and participation in an interval throwing program (81.8%) were the most common parameters emphasized in these rehabilitation protocols. While all studies included at least 1 of 3 metrics for the RTS value assessment, most commonly postoperative rehabilitation (96.97%) and set timing after surgery (96.97%), no article completely defined RTS criteria after UCLR.

CONCLUSION

Overall, 93.9% of studies report utilizing bracing with progressive ROM, 84.8% reported strengthening, and 81.8% reported participation in an interval throwing program as rehabilitation parameters after UCLR. In addition, 96.97% reported timing after surgery as a criterion for RTS; however, there is a wide variability within the literature on the recommended time from surgery to return to activity. Future research should focus on developing a comprehensive checklist of functional and performance-based criteria for safe RTS after UCLR.

Acute Ligament Injuries of the Elbow

Ulnar collateral, radial collateral, lateral ulnar collateral, and annular ligaments can be injured in an acute trauma, such as valgus stress in athletes and elbow dislocation. Recognizing normal anatomy in magnetic resonance imaging and ultrasonography studies is important to identify ligamentous abnormalities in these imaging modalities.

Clinical outcomes of a unique ulnar collateral ligament reconstruction hybrid technique with ulnar-sided suspensory fixation

BACKGROUND

Ulnar collateral ligament reconstruction (UCLR) is the gold standard for treating ulnar collateral ligament injuries in throwing athletes who have failed conservative treatment. There are several described techniques that produce successful and reproducible outcomes. In addition, there is biomechanical evidence that supports hybrid fixation of the graft with a docking technique on the humeral side and suspensory fixation on the ulnar side. However, as of this writing there are no clinical studies that have reported results. This retrospective case series is the first of its kind to report on clinical outcomes following UCLR with hybrid suspensory fixation.

METHODS

Fifty throwing athletes who underwent ULCR with hybrid suspensory fixation from 2010-2017 by one of 5 surgeons at a single institution were available at a median follow-up of 7 years. Return to sport, level of sport, and postoperative complications were recorded at final follow-up.

RESULTS

A total of 50 patients were included in final analysis. Nearly all were able to return to sport at the same level or higher (48/50, 96%). One of these 50 athletes (2%) played professionally, 27 (54%) played collegiately, and 21 (42%) played at the high school level. Seven patients (14%) underwent reoperation following the index procedure. The median (interquartile range) Quick Disabilities of the Arm, Shoulder, and Hand questionnaire score was 0.098 (0-4.5) at final follow-up.

CONCLUSION

Hybrid suspensory fixation is a safe and effective technique for UCLR in the throwing athlete. Throwers can expect to return to sport at a very high rate with low risks for postoperative complications.

Radiographic and MRI Assessment of the Thrower's Elbow

PURPOSE OF REVIEW

Throwing athletes are vulnerable to elbow injuries, especially in the medial elbow, related to high stress and valgus load in both acute and chronic settings as a result of this complex biomechanical action. This current review details the relevant anatomy and imaging features of common elbow pathology identified with radiographs and MRI in throwing athletes.

RECENT FINDINGS

Although elbow pathology in throwing athletes is well documented, advances in imaging technology and technique, particularly with MRI, have allowed for more detailed and accurate imaging description and diagnosis. Pathology of thrower's elbow occurs in predictable patterns and can be reliably identified radiologically. Clinical history and physical examination should guide radiologic evaluation initially with radiographs and followed by an MRI optimized to the clinical question. Constellation of clinical, physical, and radiologic assessments should be used to guide management.

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.

State of the Union on Ulnar Collateral Ligament Reconstruction in 2020: Indications, Techniques, and Outcomes

PURPOSE OF REVIEW

There has been a marked increase in the number of ulnar collateral ligament reconstructions performed annually and an associated increase in the amount of recent literature published. It is paramount that surgeons remain up to date on the current literature, as modern indications and surgical techniques continue to improve clinical outcomes.

RECENT FINDINGS

Our understanding of ulnar collateral ligament (UCL) injuries, treatment indications, and surgical techniques for UCL reconstruction continues to evolve. Despite the rapidly increasing amount of published literature on the topic, a clear and concise surgical algorithm is lacking. Studies have suggested a trend towards improved clinical outcomes and decreased complications with various modifications in UCL reconstruction techniques. Current sport-specific outcome studies have reported conflicting results regarding the effect of UCL reconstruction on an athlete's performance upon returning to sport. With the rising incidence of UCL reconstruction and growing media attention, UCL injuries, reconstruction techniques, and return to sport following UCL surgery are timely topics of interest to clinicians and overhead throwing athletes. Several technique modifications have been reported, and these modifications may lead to improved outcomes and lower complication rates. Studies assessing sport-specific outcome measures will be necessary to provide a more critical and informative analysis of outcomes following UCL reconstruction.