Plantar flexion with inversion shows highest elastic modulus of calcaneofibular ligament using ultrasound share wave elastography.

PURPOSE: The functional role of the calcaneofibular ligament (CFL) is still controversial. We aimed to investigate the anatomical features of the CFL on sonography and the elastic modulus of the CFL in different ankle positions using ultrasound shear-wave elastography (SWE). METHODS: In 14 cadaveric ankles, the angle of the CFL with respect to the long axis of the fibula was measured in the following ankle positions: neutral (N), 30° plantar flexion (PF), and 20° dorsiflexion (DF). In addition, in 24 ankles of healthy adult volunteers, the elastic modulus of the CFL was evaluated with ultrasound SWE in the following ankle positions: neutral (N), 30° plantar flexion with inversion (PI), 30° plantar flexion with eversion (PE), 20° dorsiflexion with inversion (DI), and 20° dorsiflexion with eversion (DE). RESULTS: The mean angle of the CFL in N, PF, and DF positions was 139.9° ± 12.7°, 121.3° ± 14.1°, and 158.6° ± 13.1°, respectively. The angle of the CFL in N was significantly greater than that in PF and smaller than that in DF (P < 0.0001, both). The mean elastic modulus of the CFL in the N, PI, PE, DI, and DE positions was: 63.6 ± 50.8, 148.0 ± 39.4, 75.8 ± 40.6, 88.1 ± 31.6, and 61.7 ± 29.4 kPa, respectively. The elastic modulus in PI was significantly higher than in other positions, while the values obtained in DI and DE were also significantly different (P < 0.001, both). CONCLUSIONS: The angle of the CFL increased with DF. Moreover, ultrasound SWE showed that the CFL was tensed and likely to be injured in the PI position.

Elasticity of the Scalene Muscles in Collegiate Baseball Pitchers Using Shear Wave Elastography.

Background: Thoracic outlet syndrome is more common in overhead athletes. The anterior and middle scalene muscles have been associated with thoracic outlet syndrome; however, the relationship between the elastic moduli of the scalene muscles and the overhead-throwing position has not been evaluated. Purpose: To investigate the elastic moduli of the anterior and middle scalene muscles in simulated throwing positions using shear wave elastography. Study Design: Descriptive laboratory study. Methods: We enrolled collegiate baseball players who underwent preseason medical checkups in January and February 2020. The anterior and middle scalene muscles were visualized in the short-axis view using ultrasound. In this view, the elastic moduli of the anterior and middle scalene muscles were measured using shear wave elastography in the following arm and neck positions: (1) adduction and neutral rotation of the shoulder (neutral), (2) 90° of abduction and external rotation of the shoulder (ABER), and (3) ABER with neck rotation toward the nonthrowing side (ABER+NR). Repeated-measures analysis of variance and a paired t test were used to compare the elastic modulus values among the 3 positions and between the 2 muscles, respectively. Results: Overall, 30 baseball players were included. In both scalene muscles, the elastic moduli were significantly greater in the ABER versus neutral position (anterior scalene: 14.4 ± 3.8 vs 9.4 ± 2.0 kPa, respectively [P < .001]; middle scalene: 15.8 ± 5.0 vs 10.9 ± 3.4 kPa, respectively [P < .001]). In the neutral position, the elastic modulus was significantly greater in the middle scalene than the anterior scalene (10.9 ± 3.4 vs 9.4 ± 2.0 kPa, respectively; P = .03). In the ABER+NR position, the elastic modulus was significantly greater in the anterior scalene than the middle scalene (18.1 ± 4.6 vs 15.8 ± 2.6 kPa, respectively; P = .03). Conclusion: Because the ABER position was a simulation of the throwing position, these results indicate that this position could be associated with high elastic moduli of the scalene muscles, and both the anterior and middle scalene muscles may be involved.

Ulnar Collateral Ligament Reconstruction With the Modified Jobe Technique in Baseball Pitchers.

BACKGROUND: Tearing and insufficiency of the ulnar collateral ligament (UCL) of the elbow result in valgus instability, which can lead to pain while throwing and decline in performance in overhead athletes. PURPOSE: To assess the clinical results of a modified UCL reconstruction technique using 1 bone hole in the ulna and 1 bone tunnel in the humerus in baseball players. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The inclusion criteria were medial elbow pain preventing effective playing, clinically medial elbow laxity, and magnetic resonance imaging results consistent with UCL injury. Patients who were engaged in other sports and in other positions in baseball except pitchers were excluded from this study. Our modified Tommy John procedure was performed via a muscle-splitting approach and an original single-bone-tunnel technique, using a suture anchor. After a minimum of 24 months, patients were evaluated using the Conway scale and the Timmerman-Andrews score. RESULTS: Of 31 patients, 20 baseball pitchers (20 male: 5 high school, 5 collegiate, 8 nonprofessional, and 2 professional pitchers) were reviewed. The mean patient age at the time of operation was 21.9 years, and the mean postoperative follow-up period was 35.1 months (range, 24-66 months). The mean Timmerman-Andrews subjective score improved significantly from pre- to postoperatively (from 68.3 to 98.3; P < .05); the objective score also improved significantly (from 81.1 to 96.4; P = .01). No complications were detected at the latest follow-up. Overall, 19 patients were able to return to their preinjury level of sports or higher. CONCLUSION: UCL reconstruction with 1 bone hole in the ulna and 1 bone tunnel in the humerus demonstrated satisfactory results in baseball pitchers. Our modified technique was safe and achieved satisfactory clinical results, with a 95% rate of return to sports.

Characteristics of Femoral Torsion Angles and Relationships Between Femoral Torsion Angles and Hip Rotational Motion Variables in Adult Baseball Players.

BACKGROUND: Abnormalities in hip rotational motion (HRM) are risk factors for throwing injuries. To evaluate hip rotational motion, it is necessary to assess the torsion angle. However, no studies have investigated the femoral torsion angle (FTA) in baseball players. PURPOSE: To investigate differences in hip FTA of adult baseball players through use of ultrasonography to evaluate the relationship between the FTA and HRM. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 149 elite male baseball players (mean age, 20.0 ± 1.8 years; 64 pitchers, 85 position players) were enrolled in this study. Ultrasonographic assessment of FTA was performed based on the tilting angles of the anterior surface of the femoral neck and condylar axis. The hip internal rotation (HIR) and hip external rotation (HER) were assessed at 0° and 90° of flexion. Data related to FTA and HRM were compared between hips and between pitchers and position players. RESULTS: No significant difference was observed in the FTAs between hips for any player (lead hip, 20.5° ± 9.2°; trail hip, 19.6° ± 9.8°; P = .276). No significant difference was observed in FTAs of both hips between pitchers and position players (lead hip, 20.1° ± 9.4° and 20.9° ± 9.0°, respectively, P = .957; trail hip, 19.5° ± 9.8° and 19.7° ± 9.8°, P = .999). In terms of HER in 90° of hip flexion in both hips, significant differences were observed in HRM variables between pitchers and position players (lead hip, 33.0° ± 8.9° and 37.5° ± 9.8°, respectively, P = .024; trail hip, 35.6° ± 9.6° and 40.4° ± 10.2°, P = .035). Linear regression analysis revealed a significant agreement between the FTA and HIR at both 0° (R = 0.298, P < .001) and 90° of hip flexion (R = 0.279, P < .001). CONCLUSION: Our findings indicated that FTAs were not different between the hips of elite baseball players. Abnormalities of the HRM are not caused by differences in the FTA but rather involve soft tissue tightness around the hip area or other bony morphologic factors in the hip joint.