Valgus laxity of the ulnar collateral ligament of the elbow in collegiate athletes

Optimal Limb Position for the Stress Ultrasound Evaluation of Elbow Valgus Laxity in Baseball Players

Background

The optimal limb position during stress ultrasound (SUS) evaluation of elbow valgus laxity has not been standardized.

Purpose

To compare 2 elbow positions (at 90° and 30° of flexion) and report which position method better represents the increased valgus laxity characteristics of baseball players.

Study Design

Controlled laboratory study.

Methods

Eighteen college baseball players with no history of elbow pain or elbow disorders who belonged to a college baseball club between April and November 2021 participated in this study. The medial elbow joint space (MEJS) was recorded by ultrasonography at rest and under valgus stress, and the difference in MEJS between the conditions was considered the valgus laxity. For all participants, the MEJS was recorded at 90° and 30° of elbow flexion. In the 90° of flexion position, the participant was positioned in the supine position with abduction and external rotation of the shoulder, and 2.5 kgf of valgus stress was applied proximally to the wrist. In the 30° of flexion position, the participant was positioned in the sitting position with abduction and external rotation of the shoulder, and 3.0 kgf of valgus stress was applied to the ulnar head. Valgus laxity on the throwing and nonthrowing sides was compared between the 2 elbow positions using paired t tests or Wilcoxon signed-rank tests after checking the normality.

Results

There was a significant difference in valgus laxity on the throwing side between the 90° and 30° of flexion positions (1.9 vs 1.1 mm, respectively; P = .002), whereas no significant difference between positions was seen on the nonthrowing side (P = .06).

Conclusion

SUS with the elbow flexed at 90° more clearly detected valgus laxity in the study participants than the 30° of flexion position.

Clinical Relevance

The quantitative evaluation of valgus laxity is important for baseball players to assess the risk of ulnar collateral ligament injury.

Medial elbow joint space gapping associated with repetitive baseball pitching in preadolescent baseball players

BACKGROUND

The baseball pitching motion creates valgus stress to the medial elbow, which contributes to increased medial elbow joint space gapping. The musculoskeletal systems of preadolescent baseball players are immature compared with those of adults, but it is unclear whether the repetitive pitching action causes an increase in medial elbow joint space gapping. This study aimed to examine differences in medial elbow joint space gapping based on the pitch count of preadolescent baseball players compared with those of adult players.

METHODS

The participants were 11 healthy preadolescent baseball players and 12 college students with baseball experience. They threw 60 maximal-effort pitches arranged into 4 sets of 15 pitches. The medial elbow joint space was measured ultrasonographically with the forearm weight before pitching and following every set of 15 pitches. Repeated-measures analysis of variance and the Bonferroni post hoc test were used to compare the medial elbow joint space among the 5 pitching sets (before pitching and after 15, 30, 45, and 60 pitches) and between the groups of preadolescent baseball players and college students.

RESULTS

There was no significant change in the medial elbow joint space gapping of the dominant elbow based on age/pitch count (F = 0.42, P = .796). There was a significant effect of pitch count (F = 30.28, P < .001) and between-group effects (F = 4.56, P = .045). The medial elbow joint space gapping increased significantly after 60 pitches in preadolescent baseball players (P = .023) and college students (P = .021). The medial elbow joint space gapping in preadolescent baseball players was significantly wider than that in college students (P = .007 before pitching, P = .027 at 15 pitches).

CONCLUSION

Sixty repetitive pitches contributed to an increase in the medial elbow joint space gapping, regardless of age. The results of this study provide further evidence when considering pitching limitations.

Changes in Medial Elbow Joint Space When Elbow Valgus Stress Is Applied at Different Limb Positions and Loads In Vivo

Background:

Ulnar collateral ligament (UCL) injury is a common sports injury among overhead-throwing athletes and causes medial elbow pain and instability. UCL injury is generally diagnosed based on symptoms, physical findings, and image evaluation. To standardize the method for evaluating elbow valgus instability, more information is needed regarding changes in the medial elbow joint space (JS) in healthy elbows.

Purpose/Hypothesis:

The purpose of this study was to measure the JS during the application of elbow valgus stress at different elbow flexion angles and loads and to clarify the presence of defensive muscle contractions during elbow valgus stress. It was hypothesized that the JS will differ according to different limb positions and loads and that defensive contractions will occur when elbow valgus stress is >90 N.

Study Design:

Controlled laboratory study.

Methods:

Elbow joints on the nondominant side were examined in 20 healthy male university students (mean age, 21 ± 0.2 years) at 30°, 60°, and 90° of elbow flexion. To create valgus stress on the elbow, loads of 30, 60, 90, 120, and 150 N were applied with a Telos stress device and with gravity stress on the forearm. The medial JS was measured ultrasonographically during the application of elbow valgus stress. Electrodes were attached to the pronator teres muscle, and defensive muscle contractions were measured using electromyography during the application of elbow valgus stress. Repeated-measures analysis of variance and paired t tests were used to compare the JS at each elbow angle and each valgus stress load, and the Bonferroni method was used as a post hoc test.

Results:

At 30° of elbow flexion, the JS was significantly higher at 30 N versus 0 N and at 60 N versus 0 or 30 N (P ≤ .018 for all). At 60° of flexion, the JS was significantly higher at 30 N versus 0 N, at 60 N versus 0 and 30 N, and at 90 N versus 0, 30, and 60 N (P ≤ .024 for all). At 90° of elbow flexion, the JS was significantly higher at 30 N versus 0 N and at 60 N versus 0 and 30 N (P ≤ .028 for all). Defensive muscle contraction did not occur at any elbow flexion angles at elbow valgus stress ≤60 N.

Conclusion:

The lack of muscular contraction at elbow valgus stress ≤60 N may reflect the function of the medial collateral ligament.

Clinical Relevance:

Elbow valgus stress ≤60 N allows for the evaluation of the joint opening.

Elbow valgus stability of the transverse bundle of the ulnar collateral ligament

Background

The purpose of this study was to clarify elbow valgus stability of the transverse bundle (TB). We hypothesized that the transverse bundle is involved in elbow valgus stability.

Methods

Twelve elbows of six Japanese Thiel-embalmed cadavers were evaluated. The skin, subcutaneous tissue and origin of forearm flexors were removed from about 5 cm proximal to the elbow to about 5 cm distal to the elbow, and the ulnar collateral ligament was dissected (intact state). The cut state was defined as the state when the TB was cut in the middle. The joint space of the humeroulnar joint (JS) was measured in the intact state and then in the cut state. With the elbow flexed to 30°, elbow valgus stress was gradually increased to 30, 60 N using the Telos Stress Device, and the JS was measured by ultrasonography under each load condition. Paired t-testing was performed to compare the JS between the intact and cut states under each load.

Results

No significant difference in JS was identified between the intact and cut state at start limb position. The JS was significantly higher in the cut state than in the intact state at both 30 N and 60 N.

Conclusion

The findings from this study suggested that the TB may be involved in elbow valgus stability.

Contributions of the Third and Fourth Digits and the Second and Fifth Digits of the Flexor Digitorum Superficialis Muscle to Elbow Valgus Stability

Background:

Thiel cadavers have been reported to have lifelike flexibility and mechanical properties, but whether they are useful for measurement of the ulnohumeral joint space (JS) is unclear. The contributions of the third and fourth digits and the second and fifth digits of the flexor digitorum superficialis (FDS) to elbow valgus stability are also unknown.

Purpose:

To (1) clarify whether Thiel cadavers can be used for JS measurement on ultrasound and (2) identify the contributions to valgus stability of the third and fourth digits and the second and fifth digits of the FDS.

Study Design:

Descriptive laboratory study.

Methods:

In experiment 1 (12 elbows from human volunteers and 12 elbows from Thiel cadavers), valgus stress was increased gradually from 0 to 30 to 60 N, and the JS was compared on ultrasound between groups at each load. In experiment 2 (13 elbows from Thiel cadavers), specimens were divided into 2 groups, and the JS was measured for group 1 with the FDS intact, with tendinous insertions of the third and fourth digits cut (3/4-cut state), and with tendinous insertions of all fingers cut (all-cut state); and for group 2 at intact FDS, with tendinous insertions of the second and fifth digits cut (2/5-cut state), and at all-cut.

Results:

In experiment 1, the rate of change of the JS increased significantly with elbow valgus stress in both humans and Thiel cadavers, with no significant difference between groups. In experiment 2, the JS was significantly greater in the 3/4- and 2/5-cut states compared with the intact state at both 30 N (Δ_{3/4-cut vs intact} = 0.23 mm [P = .01]; Δ_{2/5-cut vs intact} = 0.32 mm [P = .02]) and 60 N (Δ_{3/4-cut vs intact} = 0.33 mm [P = .002]; Δ_{2/5-cut vs intact} = 0.37 mm [P = .04]). There was no significant difference in JS measurements between the 3/4- and 2/5-cut states at any load.

Conclusion:

Thiel cadavers showed JS changes similar to those of humans when valgus stress was applied. The third and fourth digits and the second and fifth digits of the FDS were involved in valgus stability, and there was no difference in their respective contributions.

Clinical Relevance:

This study may help in identifying function of the FDS based on structure.

Material Properties of the Medial Elbow During Passive Valgus and Self-Initiated Varus Torques

Shear wave elastography imaging of the ulnar collateral ligament (UCL) is used to help understand changes in material properties of the ligament. Ensuring that the wrist flexors are relaxed is essential as muscle contractions can alter the alignment of the medial elbow. The purpose of this study was to determine how the structural and material properties of the medial elbow respond to various elbow torques. The medial elbows of 20 healthy adults, free from upper extremity disorders, were imaged in 3 of the following torque conditions: (1) neutral relaxed, (2) passive valgus, and (3) active varus. Structural properties (ulnohumeral gap and UCL length) using B-mode and material properties (UCL and flexor muscle stiffness) using shear wave were measured. Passive valgus torque opened the ulnohumeral gap (P < .001), and increased UCL (P < .001) and wrist flexor stiffness (P = .001), compared with the neutral condition. Under an active varus contraction, the gap returned back to the neutral position, but UCL (P < .008) and wrist flexor stiffness (P < .004) remained elevated compared with neutral, meaning low-intensity torques can influence structural and material properties of the medial elbow. Therefore, effort should be taken to minimize muscle activation during imaging in order to accurately measure medial elbow properties.

Comparison of Radiographic and Ultrasonographic Findings of Medial Elbow Laxity in High School Baseball Players

Background:

Although ultrasonography has been used to assess medial elbow laxity, its usefulness has not yet been confirmed.

objective:

The aim of this study were to assess medial elbow laxity in high school baseball players based on measurements of the medial joint space (MJS) of the elbow using ultrasonography and radiography and to investigate the correlation between these assessments.

Methods:

Thirty-two high school baseball players participated in this study. Fourteen players (44%) were diagnosed with Ulnar Collateral Ligament (UCL) injury. Valgus stress was applied to the elbow by gravity during ultrasonographic and radiographic assessments, and the MJS was measured. The MJS of the throwing side was compared with that of the non-throwing side, and the increase in the MJS of the throwing side was determined. The correlation between ultrasonographic and radiographic assessments was investigated and the usefulness of these assessments for the diagnosis of UCL injury was evaluated.

Results:

A moderate correlation was found between the ultrasonographic and radiographic assessments of the MJS of the throwing side (correlation coefficient=0.547, P=0.0009). Furthermore, a weak correlation was found for the increase in MJS (correlation coefficient=0.348, P=0.0505), although it was not significant. The comparisons of the radiographic assessments between the UCL injury and non-UCL injury groups showed a significant difference in both the MJS of the throwing side (P=0.0068) and the increase in the MJS (P=0.02), although no difference was found using ultrasonography.

Conclusion:

Ultrasonography, similar to radiography, is useful for assessing medial elbow laxity. While radiography is useful for diagnosing UCL injury.

Injured vs. uninjured elbow opening on clinical stress radiographs and its relationship to ulnar collateral ligament injury severity in throwers

BACKGROUND

Stress radiography measures medial joint space opening of the elbow, but its value in the management of throwing athletes is unclear. The purpose of this study was to analyze the relationship between medial joint opening (gapping and excess opening) and ulnar collateral ligament (UCL) injury severity on magnetic resonance imaging, as well as to explore factors related to the unexpected finding of a greater opening of the uninjured elbow compared with the injured elbow (negative excess opening) with valgus stress radiography.

METHODS

Medial joint space measurements were independently performed by 2 raters in a clinical series of 74 patients evaluated with standardized valgus stress radiography as part of their clinical workup for throwing-related medial elbow pain. Demographic data were collected by chart review, and UCL injury severity was classified based on available imaging into intact UCLs, partial-thickness tears of the anterior bundle, or full-thickness tears of the anterior bundle.

RESULTS

Joint gapping was related to UCL injury severity (P = .003), and group-level comparison showed a difference among tear severity groups (P = .050). Excess opening was not significantly related to UCL injury severity (P = .109). A negative excess opening was observed in 22% of patients, but no factors corroborating guarding or a mechanical explanation were significant for a decreased medial joint opening of the injured elbow compared with the uninjured elbow.

CONCLUSIONS

Medial joint gapping was correlated to UCL injury severity in throwing athletes with medial elbow pain and a clinical suggestion of UCL injury, but no association between injury severity and excess opening was observed in this clinical series, which may limit the usefulness of stress radiography in the clinical workup of throwing athletes.

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.

Valgus stress ultrasound for medial ulnar collateral ligament injuries in athletes: is ultrasound alone enough for diagnosis?

BACKGROUND

We hypothesized that valgus stress ultrasound would be useful for both identifying medial ulnar collateral ligament (MUCL) tears and assessing the severity of the tears. Hence, we performed valgus stress ultrasound of the elbow in athletes with MUCL injuries, confirmed by magnetic resonance imaging (MRI), to determine whether ultrasound can be used as a diagnostic tool.

METHODS

Stress ultrasound and MRI data from 146 athletes with medial elbow pain were compared prospectively. MRI findings for MUCL injuries were classified into 3 levels as follows: low-grade partial tear (≤50%), high-grade partial tear (>50%), and complete tear. The degree of joint laxity on stress ultrasound was evaluated by measuring joint gapping after applying a 2.5-kg load to the wrist. Joint gapping was measured at 30° and 90° of elbow flexion for the dominant arm and nondominant arm, and the differences between the dominant and nondominant arms were determined.

RESULTS

A higher degree of MUCL injury on MRI was associated with greater joint gapping in the medial elbow on stress ultrasound. At 30° of elbow flexion, the cutoff value for complete MUCL rupture was 0.5 mm (P < .001), with a sensitivity and specificity of 88.1% and 61.5%, respectively. At 90° of elbow flexion, the cutoff value for complete MUCL rupture was 1.0 mm (P < .001), with a sensitivity and specificity of 81.0% and 66.4%, respectively.

CONCLUSION

Stress ultrasound can be used to diagnose complete MUCL tears in athletes when joint gapping is greater than 0.5 mm at 30° of elbow flexion and greater than 1 mm at 90° of elbow flexion.

Understanding the medial ulnar collateral ligament of the elbow: Review of native ligament anatomy and function

The medial ulnar collateral ligament complex of the elbow, which is comprised of the anterior bundle [AB, more formally referred to as the medial ulnar collateral ligament (MUCL)], posterior (PB), and transverse ligament, is commonly injured in overhead throwing athletes. Attenuation or rupture of the ligament results in valgus instability with variable clinical presentations. The AB or MUCL is the strongest component of the ligamentous complex and the primary restraint to valgus stress. It is also composed of two separate bands (anterior and posterior) that provide reciprocal function with the anterior band tight in extension, and the posterior band tight in flexion. In individuals who fail comprehensive non-operative treatment, surgical repair or reconstruction of the MUCL is commonly required to restore elbow function and stability. A comprehensive understanding of the anatomy and biomechanical properties of the MUCL is imperative to optimize reconstructive efforts, and to enhance clinical and radiographic outcomes. Our understanding of the native anatomy and biomechanics of the MUCL has evolved over time. The precise locations of the origin and insertion footprint centers guide surgeons in proper graft placement with relation to bony anatomic landmarks. In recent studies, the ulnar insertion of the MUCL is described as larger than previously thought, with the center of the footprint at varying distances relative to the ulnar ridge, joint line, or sublime tubercle. The purpose of this review is to consolidate and summarize the existing literature regarding the native anatomy, biomechanical, and clinical significance of the entire medial ulnar collateral ligament complex, including the MUCL (AB), PB, and transverse ligament.

Revision Ulnar Collateral Ligament Reconstruction

Ulnar collateral ligament injuries continue to occur despite efforts to educate pitchers, coaches, and families at the amateur and professional levels about pitch counts, mechanics, and injury prevention. Although the data on the incidence of ulnar collateral ligament reconstructions are inconclusive, an increase in these reconstructions may mean a corresponding increase in the number of reconstruction failures and revision reconstruction surgeries. Less is known about the outcomes of revision ulnar collateral ligament reconstruction; not unexpectedly, early results are not as promising as those observed with primary reconstruction. In response, interest in revision techniques, rehabilitation, and outcomes of revision ulnar collateral ligament reconstruction surgeries has grown.

The effect of repetitive baseball pitching on medial elbow joint space gapping associated with 2 elbow valgus stressors in high school baseball players

BACKGROUND

To prevent elbow injury in baseball players, various methods have been used to measure medial elbow joint stability with valgus stress. However, no studies have investigated higher levels of elbow valgus stress. This study investigated medial elbow joint space gapping measured ultrasonically resulting from a 30 N valgus stress vs. gravitational valgus stress after a repetitive throwing task.

METHODS

The study included 25 high school baseball players. Each subject pitched 100 times. The ulnohumeral joint space was measured ultrasonographically, before pitching and after each successive block of 20 pitches, with gravity stress or 30 N valgus stress. Two-way repeated measures analysis of variance and Pearson correlation coefficient analysis were used.

RESULTS

The 30 N valgus stress produced significantly greater ulnohumeral joint space gapping than gravity stress before pitching and at each successive 20-pitch block (P < .01). For the 2 stress methods, ulnohumeral joint space gapping increased significantly from baseline after 60 pitches (P < .01). Strong significant correlations were found between the 2 methods for measurement of medial elbow joint space gapping (r = 0.727-0.859, P < .01).

CONCLUSIONS

Gravity stress and 30 N valgus stress may produce different effects with respect to medial elbow joint space gapping before pitching; however, 30 N valgus stress appears to induce greater mechanical stress, which may be preferable when assessing joint instability but also has the potential to be more aggressive. The present results may indicate that constraining factors to medial elbow joint valgus stress matched typical viscoelastic properties of cyclic creep.

The Effects of Elbow Bracing on Medial Elbow Joint Space Gapping Associated With Repetitive Throwing in High School Baseball Players

Background:

Throwing athletes risk medial elbow injury from extreme valgus stress generated across the medial elbow during throwing. Braces have been developed to protect the elbow joint; however, no previous study has investigated the effects of elbow bracing on medial elbow joint space gapping associated with repetitive throwing.

Hypothesis/Purpose:

The purpose of this study was to investigate the effects of elbow bracing on medial elbow joint space gapping during repetitive throwing. Our hypothesis was that an elbow brace may reduce mechanical stress on the elbow by reducing medial elbow joint space gapping.

Study Design:

Controlled laboratory study.

Methods:

Twenty-five high school baseball players participated in this study. Each subject pitched 100 times under 2 conditions: control (without elbow brace) and elbow brace. The ulnohumeral joint space was measured ultrasonically before pitching and after every block of 20 pitches. Measurement of the ulnohumeral joint space was carried out using ultrasound with the forearm hanging by the side. Two-way repeated-measures analysis of variance and post hoc tests were used to compare ulnohumeral joint space with repeated pitching and between the elbow brace and control conditions.

Results:

In the control condition, ulnohumeral joint space after 60 pitches was significantly greater than that before pitching (P < .01). In contrast, in the elbow brace condition, ulnohumeral joint space was not significantly different after repeated pitching. When comparing these 2 conditions, ulnohumeral joint space in the control condition was significantly greater than that in the elbow brace condition after 60 pitches (P < .01).

Conclusion:

An elbow brace has the effect of preventing medial elbow joint space gapping with repeated throwing when determined ultrasonically by measuring the ulnohumeral joint space under gravity load.

Clinical Relevance:

An elbow brace worn during baseball pitching practice may help reduce mechanical stress on the elbow by reducing medial elbow joint space gapping.

Performance and Injury Characteristics of Pitchers Entering the Major League Baseball Draft After Ulnar Collateral Ligament Reconstruction

BACKGROUND

Ulnar collateral ligament (UCL) reconstruction (UCLR) has been studied and shown to be a successful procedure for returning overhead athletes to sport. Many studies of Major League Baseball (MLB) players have shown high levels of return to play with successful statistical performance. No study has followed professional advancement of drafted pitchers who underwent UCLR as amateurs when compared with drafted pitchers who did not undergo the procedure before selection in the MLB draft.

HYPOTHESIS

There would be no difference in professional advancement, statistical performance, or injury rate between the UCLR and control groups.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Thirty-eight pitchers with a UCLR as an amateur and 114 controls were identified in the MLB draft between 2006 and 2010. Highest level of professional baseball achieved was collected from all players, as well as statistical performance metrics including velocity, wins, earned run average (ERA), and walks and hits per inning pitched (WHIP). Additional data on future injuries were analyzed for days on the disabled list (DL), risk of being placed on the DL, and DL assignment for elbow injury.

RESULTS

Thirteen of 38 UCLR pitchers reached the major league level (34.2%) compared with 29 of 114 (25.4%) control pitchers, which was not statically significant (P = .295). The UCLR and control groups were similar for average velocity, peak velocity, innings pitched, games, games started, innings per game, ERA, WHIP, wins, losses, saves, batters faced, and innings pitched per year, as well as hits, runs, home runs allowed, strikeouts, batters walked, and batters struck per inning. The UCLR group had a significantly increased rate of DL assignment when compared with controls (86.8% vs 64.0%; P = .008); however, days on DL (152.8 vs 135.6; P = .723) and DL assignment for elbow injury (45.5% vs 43.8%; P = .877) were similar.

CONCLUSION

There was no difference in the rate of professional advancement among pitchers drafted by the MLB who had undergone UCLR as amateurs compared with controls. Both groups had similar statistical performance. Pitchers in the UCLR group had an increased risk of DL assignment but no increase in the number of days on DL or risk of DL placement for elbow injury.

Reliability and precision of stress sonography of the ulnar collateral ligament

OBJECTIVES

Musculoskeletal sonography has emerged as an additional diagnostic tool that can be used to assess medial elbow pain and laxity in overhead throwers. It provides a dynamic, rapid, and noninvasive modality in the evaluation of ligamentous structural integrity. Many studies have demonstrated the utility of dynamic sonography for medial elbow and ulnar collateral ligament (UCL) integrity. However, evaluating the reliabilityand precision of these measurements is critical if sonography is ultimately used as a clinical diagnostic tool. The purpose of this study was to evaluate the reliability and precision of stress sonography applied to the medial elbow.

METHODS

We conducted a cross-sectional study during the 2011 baseball off-season. Eighteen National Collegiate Athletic Association Division I pitchers were enrolled, and 36 elbows were studied. Using sonography, the medial elbow was assessed, and measurements of the UCL length and ulnohumeral joint gapping were performed twice under two conditions (unloaded and loaded) and bilaterally.

RESULTS

Intraclass correlation coefficients (0.72-0.94) and standard errors of measurements (0.3-0.9 mm) for UCL length and ulnohumeral joint gapping were good to excellent. Mean differences between unloaded and loaded conditions for the dominant arms were 1.3 mm (gapping; P < .001) and 1.4 mm (UCL length; P < .001).

CONCLUSIONS

Medial elbow stress sonography is a reliable and precise method for detecting changes in ulnohumeral joint gapping and UCL lengthening. Ultimately, this method may provide clinicians valuable information regarding the medial elbow's response to valgus loading and may help guide treatment options.

How much valgus instability can be expected with ulnar collateral ligament (UCL) injuries? A review of 273 baseball players with UCL injuries

BACKGROUND

The dynamic stress radiograph of the elbow was designed to help the clinician better define valgus laxity and instability in the throwing athlete. However, no large study has quantified the amount of laxity in athletes with ulnar collateral ligament (UCL) injuries. We hypothesized that valgus stress radiographs in patients with UCL injuries will demonstrate a significantly greater amount of valgus stress opening of the dominant elbows compared with the nondominant elbow.

METHODS

Bilateral elbow static and stress radiographs that were taken as part of our standard preoperative workup were retrospectively reviewed in 273 baseball players who had undergone UCL reconstruction. The valgus stress radiograph protocol used a Telos stress device (SE 2000) to provide 15 daN of stress in a standardized fashion.

RESULTS

The thrower's elbow with a UCL injury opened 0.4 mm more than the uninjured side. Those with complete tears (N = 76), determined by magnetic resonance imaging findings, opened 0.6 mm on average, which was significantly more than in those with partial tears (N = 150), which opened an average of 0.1 mm.

CONCLUSION

Stress radiography of the dominant elbow in baseball players with UCL injuries showed it to have 0.4 mm greater opening compared with the nondominant arm. Larger average openings (0.6 mm) can be expected with full-thickness UCL tears compared with partial-thickness tears (0.1 mm). This suggests that large openings on stress radiography may not be a critical component for predicting who will require surgical reconstruction for UCL injuries but may be more useful in differentiating complete from partial tears.

Assessment of medial elbow laxity by gravity stress radiography: comparison of valgus stress radiography with gravity and a Telos stress device

BACKGROUND

Valgus instability was reported to be higher with the elbow in 60° of flexion, rather than in 30° of flexion, although there are no studies using valgus stress radiography by gravity (gravity radiography) with the elbow in 60° of flexion.

METHODS

Fifty-seven patients with medial elbow pain participated. For both elbows, valgus stress radiography by use of a Telos device (Telos radiography) and gravity radiography, with the elbow in 60° of flexion, were performed for the assessment of medial elbow laxity. In both radiographs, the medial elbow joint space (MJS) on the affected side was compared with that on the opposite side, and the increase in the MJS on the affected side was assessed.

RESULTS

For the Telos radiographs, the mean MJS was 4.7 mm on the affected side and 4.0 mm on the opposite side, with the mean increase in the MJS on the affected side being 0.7 mm. For the gravity radiographs, the mean MJS was 5.0 mm on the affected side and 4.2 mm on the opposite side, with the mean increase in the MJS on the affected side being 0.8 mm. There were significant correlations between the Telos and gravity radiographs in the MJS on the affected side, the MJS on the opposite side, and the increase in the MJS on the affected side (respectively, P < .0001). There was also a high level of intraobserver and interobserver reliability for the assessment of the gravity radiographs.

CONCLUSIONS

Gravity radiography is useful for assessment of medial elbow laxity, similar to Telos radiography.

Medial elbow injury in young throwing athletes

This report reviews the anatomy, overhead throwing biomechanics, injury mechanism and incidence, physical examination and diagnosis, diagnostic imaging and conservative treatment of medial elbow injuries in young throwing athletes. Based on the information a clinical management decision-making algorithm is presented.

A new manual method for assessing elbow valgus laxity

Background

A screening of ulnar collateral ligament insufficiency is required for overhead throwers, since secondary pathologic changes result from an increased elbow valgus laxity. We developed a new manual method for assessing elbow valgus laxity and investigated the reliability of this method and its correlation with ultrasonographic assessment.

Methods

We defined elbow valgus laxity as the difference between the shoulder external rotation angle (ER angle) measured with the elbow in 90 degrees flexion and that measured with the elbow in extension because ER angle measured with the elbow in 90 degrees flexion includes elbow valgus laxity and ER angle with the elbow in extension does not include it. ER angle measurement with the elbow in extension involved the use of a custom arm holder. Three examiners each measured elbow valgus laxity by the new method in 5 healthy volunteers. Intraobserver and interobserver reliability was evaluated by calculating the intraclass correlation coefficient. We then assessed 19 high-school baseball players with no complaints of shoulder or elbow pain. Elbow ultrasonography was performed with a 10-MHz linear transducer with the elbow in 90 degrees flexion, and the forearm in the neutral position, and the width of the medial joint space at the level of the anterior bundle was measured. Elbow valgus laxity assessed by ultrasonography was defined as the difference between the medial joint space width with gravity stress and that without gravity stress. Increased elbow valgus laxity assessed by both our method and ultrasonography was defined as the difference between the laxity of the elbow on the throwing side and that on the contralateral side. Pearson's correlation coefficient (r) was calculated to evaluate the relationship between increased elbow valgus laxity obtained by our manual method and that by ultrasonography.

Results

Intraobserver reliability ranged from 0.92 to 0.98, and interobserver reliability was 0.70. The increased elbow valgus laxity assessed by our method was significantly correlated with that assessed by ultrasonographic assessment (P = 0.019, r = 0.53).

Conclusions

Elbow valgus laxity can be assessed by our method. This method may be useful for screening for insufficiency of the ulnar collateral ligament.

Long-term results of ulnar collateral ligament reconstruction in throwing athletes based on a hybrid technique

BACKGROUND

Tearing or attenuation of the ulnar collateral ligament (UCL) of the elbow is a common injury in the throwing athlete. Several techniques for reconstruction of the attenuated or torn UCL have been developed.

HYPOTHESIS

Ulnar collateral ligament reconstruction based on a hybrid technique, with an ulnar osseous tunnel and suture anchor fixation on the humerus, allows throwing athletes to return to prior activity level and has a low complication rate.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review was performed of the UCL reconstructions performed in 34 throwing athletes, as based on a hybrid technique, over a 6-year period. All elbows were reconstructed with a tendon graft fixed through an osseous tunnel placed at the sublime tubercle and with 2 suture anchors placed into a bony trough at the humeral origin of the native ligament.

RESULTS

Average postoperative follow-up was 6.9 years (range, 4.2 to 8.7 years). The average age was 20.2 years, with symptoms present for an average of 22.4 weeks before clinic presentation. Each athlete had pain with valgus stress or milking maneuver in addition to a documented tear of the UCL on magnetic resonance imaging. All experienced pain on the medial aspect of the elbow while throwing. Only 1 patient had new onset of temporary ulnar nerve paresthesia, for a complication rate of 2%. Of 34 athletes, 29 (85%) had an excellent result, defined as the ability to return to play at or above preinjury level. Of the 5 patients who did not return to preinjury level, only 2 were unable to do so secondary to pain.

CONCLUSION

Ulnar collateral ligament reconstruction based on a hybrid fixation technique results in a low complication rate and allows full recovery to preinjury level of performance in the majority (85%) of patients.

Fencing

Fencing is a sport in which two people attempt to score points by making their weapon (epee, foil, or saber) contact their opponent. The most common types of injury seen in fencing are weapon injuries; strains, sprains, and trauma; and nontraumatic injuries, the pathologic findings of which are discussed in this article.

Sports injuries of the elbow

There is a wide spectrum of pathology that affects the elbow in the athlete. This is further complicated by the complex anatomy of this articulation and the numerous normal anatomic variations that can serve as pitfalls in imaging diagnosis. A detailed knowledge of the anatomy and pathology that commonly affect this articulation can facilitate the ease and accuracy of imaging diagnosis.

Sonography of the medial collateral ligament of the elbow: a study of cadavers and healthy adult male volunteers

OBJECTIVE

We assessed the ability of high-resolution sonography to reveal the size and echogenicity of the anterior bundle of the normal medial collateral ligament of the elbow in cadavers and uninjured male volunteers.

MATERIALS AND METHODS

The anterior bundle of the medial collateral ligament in five cadaveric elbows was imaged and injected with contrast material by experienced musculoskeletal radiologists using a 12-MHz linear array transducer. Immediate ligament dissection was performed. The bilateral ligaments in 30 healthy 21- to 34-year-old male volunteers were imaged with gravitational stress. Of these, five randomly selected subjects also received approximately 5 lb (11.3 kg) of applied stress.

RESULTS

Contrast material was injected directly into all five cadaveric ligaments. The anterior bundle of the medial collateral ligament in all 30 asymptomatic male volunteers was hyperechoic in comparison with surrounding muscle and had a fibrillar pattern and fanlike shape. Its mean dimensions were 2.6 +/- 0.31 x 2.2 +/- 0.47 x 4.0 +/- 0.88 mm on the right and 2.6 +/- 0.36 x 2.1 +/- 0.42 x 4.0 +/- 0.86 mm on the left, in longitudinal short, transverse short, and transverse long axes, respectively. Differences in ligament measurements in sidedness, stress application, and hand dominance did not approach statistical (Bonferroni corrected, p > 0.01) or clinical (all differences, <0.2 mm) significance.

CONCLUSION

Radiologists can accurately use sonography to identify and measure the size of the anterior bundle of the normal medial collateral ligament of the elbow. These baseline parameters for the normal ligament may prove useful when evaluating the injured ligament.

Hyperextension trauma to the elbow: radiological and ultrasonographic evaluation in handball goalkeepers

OBJECTIVE

To detect elbow lesions produced by hyperextension in 30 elite handball goalkeepers.

METHODS

Conventional radiographs, stress radiographs, and ultrasound examination of both elbows were used. As a control group, 30 male volunteers from the general population within the same age group with no history of elbow injury were used.

RESULTS

Radiographic findings in the goalkeepers were osteophyte formation in 67%, loose bodies in 5.5%, and periarticular calcification in 5.5%. Significantly greater differences in medial joint space opening between stressed and unstressed elbows were measured in both elbows than in the control group. Ultrasonographic findings showed thickening of the medial collateral ligament in 50%, thickening of the tricipital tendon in 11%, and signs of ulnar neuritis in 22%. An intra-articular effusion was found in 66% and small loose bodies in 33%. No significant differences were found between the dominant and non-dominant elbows at radiological and ultrasound examination. The findings in the control group were normal.

CONCLUSIONS

The findings support the theory that repetitive hyperextension trauma to the elbow in handball goalkeepers results in pathological changes.

Stress injury of the proximal ulna in professional baseball players

BACKGROUND

To date, stress injury of the proximal ulna has been infrequently reported as a cause of elbow pain in the throwing athlete.

PURPOSE

We describe a syndrome of osseous stress injury of the proximal ulna in the professional throwing athlete.

STUDY DESIGN

Retrospective review.

METHODS

We evaluated the clinical, radiographic, and magnetic resonance imaging findings of seven professional baseball players with osseous stress injury of the proximal ulna.

RESULTS

Plain radiographs of the involved elbows failed to demonstrate any significant findings. All of the clinically significant lesions were detected with magnetic resonance imaging. In addition, magnetic resonance imaging was found to be of value in following the course of healing of the injuries. All of the lesions originated on the posteromedial aspect of the proximal ulna. The ulnar collateral ligament was intact in all seven athletes. One athlete had two occurrences of this injury. Six of the seven athletes returned to their previous level of play after a nonoperative course of treatment.

CONCLUSIONS

We believe that this injury should be considered in the differential diagnosis of elbow pain in the throwing athlete. Magnetic resonance imaging is the diagnostic test of choice when this injury is suspected.