The latest medical research on Sports & Exercise Medicine

There may be an association between repetitive stress on the elbow and capitellar osteochondritis dissecans (COCD). The influence of activity on the characteristics or specific location of the lesion within a capitellar zone of propensity remains unclear.

The purpose of this study was to evaluate COCD in gymnasts and baseball players compared with a non-upper extremity (non-UE) sport COCD cohort. It was hypothesized that activity would influence presentation and lesion location and characteristics.

Cross-sectional study, Level of evidence, 3.

Consecutive patients presenting with COCD treated in a tertiary sports medicine practice between March 2006 and March 2021 were reviewed. Demographic and imaging lesion characteristics were recorded. The sagittal inclination angle position of the lesion center relative to the humeral shaft was recorded. Intra- and interrater reliability was confirmed (intraclass correlation coefficient, 0.808; intraclass correlation coefficient, 0.824, respectively). Participants were analyzed by activity.

A total of 126 elbows were identified: 68 in gymnasts, 31 in baseball players, and 27 in patients with no history of UE sports. The mean age of the participants was 12.5 years (range, 8-18 years). All (100%) unilateral cases of osteochondritis dissecans (OCD) in baseball players occurred in the dominant throwing arm, compared with less hand-dominance correlation in gymnasts (64%) and non-UE athletes (67%). Significantly, 14 of the 20 (70%) patients with bilateral OCD were gymnasts (P = .036). In non-UE athletes, lesions occurred at a mean sagittal inclination angle of 52.7° (±13.8°), with a mean lateral containment of 4.7 (±2.1) mm. In gymnasts, lesions occurred more posteriorly at 41.2° (±14.9°), with a lateral containment of 3.6 (±1.9) mm. In baseball players, COCDs occurred at 55.1° (±11.9°), with a lateral containment of 2.5 (±1.6) mm. These more posterior lesion positions in gymnasts (P = .001) and lesser lesion containment noted in gymnasts (P = .015) and baseball players (P < .001) were significant.

Compared with COCD lesions in adolescents with no history of UE sports, gymnastics participation (impact weightbearing) correlated with a higher rate of bilateral lesion formation and a more posterior (extended) lesion position. Baseball participation (resulting in valgus shear forces in the elbow) resulted in a sagittal position similar to non-UE lesions, but more lateral and with less containment.

The insufficient regeneration of fibrocartilage at the tendon enthesis is the primary cause of retearing after surgical reattachment of the rotator cuff. Exosomes derived from bone marrow-derived mesenchymal stem cells (BMSC-Exos) and kartogenin (KGN) have been demonstrated to induce fibrocartilage formation. Loading drugs into exosomes may lead to a synergistic effect, significantly enhancing the inherent activity of both components. However, further investigation is necessary to determine whether loading KGN into BMSC-Exos could yield superior efficacy in promoting tendon enthesis healing.

To study the effect and mechanism of KGN-loaded BMSC-Exos (Kl-BMSC-Exos) on tendon enthesis repair and biomechanical properties in a rat rotator cuff injury (RCI) model.

Controlled laboratory study.

The characteristics and in vivo retention of exosomes were demonstrated using nanoflow cytometry, transmission electron microscopy, and in vivo imaging of a small animal. The differentiation markers of BMSCs were assessed through quantitative polymerase chain reaction and immunofluorescence assays. Unilateral supraspinatus tenotomy and repair were performed in rats to establish the RCI model. Gelatin sponges were utilized to contain and deliver exosomes. In total, 44 rats were randomly assigned to 4 groups: sham, RCI, BMSC-Exos, and Kl-BMSC-Exos. Tendon enthesis regeneration and biomechanical properties were evaluated 8 weeks after surgery. RNA sequencing of BMSCs was performed to elucidate the underlying mechanism through which Kl-BMSC-Exos enhance tendon enthesis healing.

No discernible disparities in fundamental characteristics were evident between BMSC-Exos and Kl-BMSC-Exos. Incorporating exosomes into a gelatin sponge extended the in vivo retention time from 7 to 14 days. Kl-BMSC-Exos were more effective in inducing differentiation markers of BMSCs, improving fibrocartilage regeneration, organizing collagen fiber arrangement, and enhancing the biomechanical properties of tendon enthesis. Furthermore, transcriptomics suggested that Mospd1 was involved in Kl-BMSC-Exos-mediated tendon enthesis healing by enhancing fibrocartilage regeneration.

The incorporation of exosomes into a gelatin sponge significantly enhances their in vivo retention time. Kl-BMSC-Exos can expedite the healing of RCI by enhancing chondrogenesis and fibrocartilage regeneration, providing more organized collagen fiber arrangement and superior biomechanical properties of the rotator cuff enthesis. The promotion of rotator cuff enthesis regeneration may contribute to enhancing the chondrogenic potential in BMSCs through Kl-BMSC-Exos-mediated upregulation of Mospd1.

As a cell-free therapeutic approach, Kl-BMSC-Exos displayed a better therapeutic effect on tendon enthesis healing than BMSC-Exos did, and these can be used as a biologic augmentation to enhance the healing of rotator cuff enthesis.

Sleep disturbance is commonly reported by patients wearing an abduction brace after arthroscopic rotator cuff repair (ARCR). Although a sling has been proven noninferior to an abduction brace for function and repair integrity, there is no evidence-based medical support for the advantage of the sling in improving sleep quality compared with a brace.

This study aimed to compare the effects of a sling and an abduction brace on sleep quality and clinical outcomes after ARCR. It was hypothesized that immobilization in a sling would result in better sleep quality while not deteriorating clinical outcomes and bone-tendon healing compared with an abduction brace.

Randomized controlled trial; Level of evidence, 1.

A total of 142 consecutive patients with rotator cuff tears were randomly assigned to 2 groups: (1) the brace group, receiving abduction brace immobilization for 6 weeks, and (2) the sling group, receiving sling immobilization after ARCR for 6 weeks. The primary outcome was the Pittsburgh Sleep Quality Index at 6 weeks postoperatively. Secondary outcomes-American Shoulder and Elbow Surgeons score, Self-rating Anxiety Scale, pain, satisfaction, and tendon healing (using ultrasonography)-were evaluated until 1 year postoperatively.

Complete outcome measurements were obtained for 131 patients. The Pittsburgh Sleep Quality Index at 6 weeks was 11.1 ± 2.7 for the brace group and 9.2 ± 2.3 for the sling group (P < .001), indicating a statistically significant advantage for the sling group. The sling group also reported significantly lower Self-rating Anxiety Scale, lower pain level, and higher satisfaction scores at 6 weeks. No significant difference was observed in outcome measures between groups at 1 year. The tendon healing rates (91% vs 88%, respectively) were comparable between the brace and sling groups within the first 1 year (risk ratio, 1.03 [95% CI, 0.92-1.16]; P = .59).

The use of a sling resulted in better sleep quality, less anxiety, and higher satisfaction compared with an abduction brace in the first 6 weeks after ARCR; nevertheless, functional outcomes and repair integrity were similar at 1 year postoperatively between the 2 groups. These findings indicate that a sling is appropriate for the postoperative care of ARCR. However, caution should be used when interpreting these results because the clinical relevance of sling-related benefits warrants further investigation.

ChiCTR2200059967 (Chinese Clinical Trial Registry).

Latissimus dorsi tendon transfer (LDTT) leads to good clinical outcomes and recovery of function. A previous study have evaluated the outcomes of LDTT at a minimum 10-year follow-up and found durable improvements in shoulder function and pain relief but observed that shoulders with fatty infiltration of the teres minor muscle and insufficiency of the subscapularis muscle tended to have inferior results.

To evaluate the outcomes of LDTT with a minimum follow-up of 10 years in a sizeable cohort for the treatment of irreparable posterosuperior massive rotator cuff tears (mRCTs).

Case series; Level of evidence, 4.

Patients who underwent LDTT for irreparable mRCTs between 2004 and 2013, performed by the same senior surgeon, were included in this study. All intraoperative and postoperative complications, as well as whether patients required conversion to reverse shoulder arthroplasty (RSA), were noted. At a minimum follow-up of 10 years, an independent observer collected range of motion measurements and clinical scores, including those for the Constant score, the Subjective Shoulder Value, and a visual analog scale for pain; the subacromial space was also assessed.

A total of 143 patients (147 shoulders) that underwent LDTT, with a minimum follow-up of 10 years, were included; of these, 24 patients (24 shoulders, 16%) were lost to follow-up, 1 patient (1 shoulder, 0.7%) died 9 years after the index procedure for reasons unrelated to shoulder surgery, and 18 patients (18 shoulders, 12%) required conversion to RSA, of which 6 underwent conversion at ≥6 years after LDTT. The remaining 101 patients (104 shoulders), including 3 patients who were scheduled to undergo RSA, were assessed at a mean time of 12.3 ± 2.2 years (range, 10-20 years) after index LDTT, comprised 52 men (53 shoulders) and 49 women (51 women) and had a mean age of 61.6 ± 8.0 years (range, 39-81 years) at the time of index surgery. Complications were noted in 14 shoulders, of which 4 required a reoperation. The Constant score improved by 34.2 ± 11.7 points, the adjusted Constant score by 43.5 ± 15.3 points, and the Subjective Shoulder Value score by 50.4 ± 16.4 points. The subacromial space decreased by 0.3 ± 2.0 mm.

At a minimum follow-up of 10 years, LDTT for the treatment of irreparable posterosuperior mRCTs led to satisfactory clinical scores. Of the 147 shoulders that underwent LDTT, 18 (12%) required conversion to RSA.