Pain Is the Most Frequently Cited Reason Athletes Fail to Return to Sport After Ulnar Collateral Ligament Surgery: A Systematic Review and Meta-analysis

Background

No previous systematic review to our knowledge has examined the reasons that athletes fail to return to sport (RTS) after ulnar collateral ligament (UCL) surgery.

Purpose

To report the rate of failure to RTS after UCL surgery and identify reasons that preclude an athlete's ability to successfully RTS.

Study Design

Systematic review; Level of evidence, 4.

Methods

This study was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We searched the PubMed, Scopus, and SPORTDiscus databases for studies on athletes who underwent either UCL reconstruction or repair that reported RTS rates and identified reasons for failure to RTS. Data were collected on the number of athletes included, average age, sport played, operative technique, average follow-up, rate of failure to RTS, and reasons for failure to return. A random-effects model was used to conduct the meta-analysis.

Results

Included were 26 studies reporting on 1019 athletes. Primary or revision UCL reconstruction was performed in 913 patients (89.6%), while the remaining 106 patients (10.4%) underwent UCL repair. The pooled rate of failure to RTS after UCL reconstruction or repair was calculated to be 11.4% (95% CI, 8.4-14.7). A significantly higher estimated proportion of athletes failed to return because of elbow-related reasons compared with non-elbow-related reasons (55.3% vs 40.6%; P = .0352). Persistent pain (29/103; 28.2%) was the most common reason for failure to return, followed by elbow limitations and other unspecified elbow problems (19/103; 18.4%). There was moderate evidence for publication bias and study heterogeneity across the included studies.

Conclusion

This meta-analysis estimated the rate of failure to RTS after UCL surgery as 11.4%, with the majority of athletes unable to return because of elbow pain. Future studies reporting outcomes and providing details as to why athletes are unable to RTS can better inform sport surgeons on factors precluding RTS and can guide clinical practice to better help athletes achieve their postoperative goals.

Update on injury epidemiology in rowing: our experience with female NCAA Division I athletes and a systematic review of the literature

OBJECTIVES

(1) To report the distribution of injuries per body site and time lost from participation in female NCAA Division I rowers and (2) to present an updated summary of the existing evidence regarding the analysis of injuries per body site in rowers.

METHODS

Case series: The distribution of injuries per body site in female NCAA Division I rowers and the time lost from participation were retrieved from an institutional registry. Injuries per body site were reported as number of athletes with site-specific injury per total number of injured athletes. Systematic review: Based on the PRISMA guidelines for systematic reviews, three electronic databases were searched for studies reporting the epidemiology of injuries per body site in rowers and analyzed.

RESULTS

Case series: One-hundred and thirty-seven injuries were recorded in 92 female rowers over 5 years. The risk of injury (number of injured athletes over total number of athletes on roaster) was 52% (92/176). Among the 92 injured athletes, 38% sustained injury to the lower back, while 23% and 16% of these athletes sustained injury to the ribs and hip-groin area, respectively. Systematic review: Ten studies were included. The level of evidence was IV and the mean MINORS score was 13.2(9-15) (fair quality). Most studies reported injuries to the lower spine (8/10,80%) whereas injuries to the ribs or other anatomic sites were reported in ≤4 (40%) studies. Significant heterogeneity of the injury reporting methodologies (injury definition; measures of injury occurrence; description of the injury site) was detected and precluded meta-analysis.

CONCLUSIONS

Most injuries recorded in a single team of female NCAA Division I athletes occurred in the lower back followed by injuries to the ribs and the hip. The existing injury epidemiology literature in mostly focuses on injuries to the lower back, while injuries to other anatomic sites were less frequently analyzed. No conclusions can be made regarding the most common injuries in rowers based on the current evidence due to substantial heterogeneity of injury reported methodologies which warrants further investigation.

Single position lumbar fusion: a systematic review and meta-analysis

BACKGROUND CONTEXT

Recently, a single position lumbar fusion has been described in which both the anterior or lateral interbody fusion as well as posterior percutaneous pedicle screw fixation are performed in a single position.

PURPOSE

The purpose of this study was to present and analyze the current evidence for single position lumbar fusion.

STUDY DESIGN/SETTING

This is a systematic review and meta-analysis.

PATIENT SAMPLE

Prospective or retrospective studies published in English that assessed outcomes of single position lumbar fusion surgery for patients with lumbar degenerative disease, spondylolisthesis, or radiculopathy were included.

OUTCOME MEASURES

Outcome measures included operative time, estimated blood loss, hospital length of stay, X-Ray exposure time, and postoperative outcomes including leg numbness or pain, leg weakness, lumbar lordosis, and segmental lordosis.

METHODS

This systematic review was performed in accordance with PRISMA guidelines. Two separate meta-analyses were performed. The first compared single position (SP) surgery, both lateral and prone, to dual position or flipped (F) surgery. The second meta-analysis compared lateral single position (LSP) surgery to prone single position (PSP) surgery. Variables were included if (1) they were a mean with a reported standard deviation or (2) if they were a categorical variable. For calculating standard error of the mean, we used sample size, mean, and standard deviation. A random effects model was used. The heterogeneity among studies was assessed with a significance level of <0.05.

RESULTS

Twenty-one articles were included for analysis. Three studies were prospective nonrandomized studies, while 18 were retrospective. Seven articles studied lateral single position only, 10 articles compared lateral single position to traditional repositioning surgery, three articles studied prone single position surgery, and one article compared prone single position surgery to traditional repositioning surgery. A detailed review is provided for all 21 articles. Seventeen studies were included for meta-analysis comparing the SP versus F groups, for a total of 942 patients in the SP group and 254 in the F group. Mean operative time was significantly less for the SP group compared with the F group (SP: 127.5±7.9, F: 188.7±15.5, p<.001). Average hospital length of stay was 2.87±0.3 days in the SP group and 6.63±0.6 days in the F group (p<.001). Complication rates did not significantly differ between groups. Pedicle screws placed in the lateral position had a higher rate of complication as compared with those placed in a prone position (L: 10.2±2%, P: 1.6±1%, p=.015). Seventeen studies were included in the LSP versus PSP analysis, including 13 in the LSP group and four in the PSP group, with a total of 785 patients in the LSP group and 85 patients in the PSP group. Operative time and X-Ray exposure was significantly less in the LSP compared with the PSP group (117.1±5.5 minutes vs. 166.9±21.9 minutes, p<.001; 43.7±15.5 minutes vs. 171.0±25.8 minutes, p<.001). Postoperative segmental lordosis was greater in the prone single position group (p<.001).

CONCLUSIONS

Single position surgery decreases operative times and hospital length of stay, while maintaining similar complication rates and radiographic outcomes. PSP surgery was found to be longer in duration and have increased radiation exposure time compared with LSP, while increasing postoperative segmental lordosis.

Noncanonical Gβ Gib2 is a scaffolding protein promoting cAMP signaling through functions of Ras1 and Cac1 proteins in Cryptococcus neoformans

Gβ-like/RACK1 functions as a key mediator of various pathways and contributes to numerous cellular functions in eukaryotic organisms. In the pathogenic fungus Cryptococcus neoformans, noncanonical Gβ Gib2 promotes cAMP signaling in cells lacking normal Gpa1 function while displaying versatility in interactions with Gα Gpa1, protein kinase Pkc1, and endocytic intersectin Cin1. To elucidate the Gib2 functional mechanism(s), we demonstrate that Gib2 is required for normal growth and virulence. We show that Gib2 directly binds to Gpa1 and Gγ Gpg1/Gpg2 and that it interacts with phosphodiesterase Pde2 and monomeric GTPase Ras1. Pde2 remains functionally dispensable, but Ras1 is found to associate with adenylyl cyclase Cac1 through the conserved Ras association domain. In addition, the ras1 mutant exhibits normal capsule formation, whereas the ras1 gpa1 mutant displays enhanced capsule formation, and the ras1 gpa1 cac1 mutant is acapsular. Collectively, these findings suggest that Gib2 promotes cAMP levels by relieving an inhibitory function of Ras1 on Cac1 in the absence of Gpa1. In addition, using GST affinity purification combined with mass spectrometry, we identified 47 additional proteins that interact with Gib2. These proteins have putative functions ranging from signal transduction, energy generation, metabolism, and stress response to ribosomal function. After establishing and validating a protein-protein interactive network, we believe Gib2 to be a key adaptor/scaffolding protein that drives the formation of various protein complexes required for growth and virulence. Our study reveals Gib2 as an essential component in deciphering the complexity of regulatory networks that control growth and virulence in C. neoformans.