Chalmers, Peter N.

Objectives: While pitch count and rest guidelines have been promoted for youth and adolescent baseball players for nearly two decades, compliance with guidelines remains poorly understood. The purpose of this study was to determine the frequency of compliance with Pitch Smart guidelines, as well as the association between compliance and range of motion, strength, velocity, injury, and pitcher utilization. Methods: This study was a prospective, multi-center study of high school pitchers, encompassing each region of the United States. Pre-season pitchers were surveyed about their compliance with current off- season rest-related guidelines and history of injury. Pre-season, pitchers underwent standardized physical examinations and pitch velocity was measured. During the high school season that followed, both pitch counts and injury incidence were collected. Results: One hundred and fifteen pitchers participated. Based upon pre-season data, 84% of pitchers had previously violated current pitch recommendation guidelines. During the season, 14% had at least one instance of a violation of the current pitch counts guidelines. Across both the pre-season survey and in-season pitch counts, 89% of players had at least one violation of the current Pitch Smart guidelines. While there were no significant differences in range of motion or strength, those pitchers who were non-compliant with guidelines in the pre-season had higher max pitch velocity (mean±standard deviation 74±8 miles per hour vs. 69±5 miles per hour, p=0.009). Pitchers self-reported their peak velocity at 7 MPH greater than the actual measured velocity. Only a single injury occurred during the season, precluding a comparison between groups. There were no significant differences in the incidence of a history of injury between those pitchers who were noncompliant with between-season rest guidelines (p=0.285). Conclusions: Most high school pitchers are non-compliant with current Pitch Smart guidelines, and they tend to overestimate their peak velocity by 7 MPH. Pitchers with greater velocity were at the highest risk for violating current pitch count recommendations. Since both increased throwing volume and pitch velocity are known risk factors for injury, these athletes may be at particular risk for subsequent injury. research is necessary to understand whether taking three consecutive month rest between seasons prevents pitching-related injury.

Background: The application of orthobiologics at the time of arthroscopic rotator cuff repair (RCR) has received an increasing amount of clinical interest despite a relative scarcity of human clinical studies on their efficacy. Purpose: To utilize a national administrative database to determine the association of bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP) applied at the time of RCR with revision surgery rates. Study Design: Cohort study; Level of evidence, 3. Methods: The Mariner data set from the PearlDiver patient records repository was utilized to identify patients undergoing RCR using Current Procedural Terminology (CPT) code 29827. Patients receiving BMAC or PRP at the time of RCR were then identified using CPT coding. For comparison purposes, a matched cohort was created consisting of patients who underwent RCR without biologic augmentation in a 5:1 fashion for each biologic separately. Cases were matched according to age, sex, tobacco use, biceps tenodesis, distal clavicle excision, and subacromial decompression. All groups were then queried for revision RCR or conversion to reverse shoulder arthroplasty. Revision rates were compared utilizing a multivariate binomial logistic regression analysis. Adjusted odds ratios (ORs) and 95% CIs were calculated. Results: A total of 760 patients who underwent biologic augmentation during RCR were identified, including 646 patients in the PRP group and 114 patients in the BMAC group. They were compared with 3800 matched controls without documented biologic application at the time of surgery. Compared with matched controls, patients who received BMAC at the time of surgery experienced a significantly lower incidence of revision surgery at 2 years (OR, 0.36; 95% CI, 0.15-0.82; P = .015). There was no significant difference in revision rates between PRP and matched controls (OR, 0.87; 95% CI, 0.62-1.23; P = .183). Conclusion: The application of BMAC at the time of RCR was associated with a significant decrease in the incidence of revision surgery. There was no apparent effect of PRP on the incidence of revision surgery after primary RCR. Higher-level clinical studies considering surgical factors are needed to more clearly define the role of biologic adjuvants in RCR.

Background: Anterior cruciate ligament reconstruction (ACLR) is the gold standard treatment for ACL tears to allow baseball players to return to sport (RTS). The optimal graft type and femoral tunnel drilling technique are currently unknown. Hypothesis: There is a high rate of RTS in professional baseball players after ACLR, with no significant difference in RTS rates or performance between cases and controls or between graft types or femoral drilling techniques. Study Design: Cohort study; Level of evidence, 3. Methods: All professional baseball players who underwent ACLR between 2010 and 2015 were included. Demographic and performance data (pre- and postoperative) for each player were recorded. Performance metrics were then compared between cases and matched controls. Results: A total of 124 players (mean age, 23.7 ± 4.1 years; 83% minor league players) underwent ACLR. Of these, 80% returned to sport (73% to the same or higher level) at a mean 310 ± 109 days overall and 333 ± 126 days at the same or higher level. The most common graft type was an ipsilateral bone–patellar tendon–bone (BTB) autograft (n = 87; 70%). A total of 91 players underwent concomitant meniscal debridement or repair. No significant difference in any of the primary performance metrics existed from before to after ACLR. Compared with matched controls, no significant difference existed in RTS rates or any performance metrics after ACLR. No significant difference existed in RTS rates or primary performance outcome measures between graft types or femoral drilling techniques. Conclusion: The RTS rate for professional baseball players after ACLR was 80%. No significant difference in performance metrics existed between BTB and hamstring autografts or between femoral drilling techniques. Furthermore, no significant difference in performance or RTS rates existed between cases and matched controls. Femoral drilling technique and graft type did not affect performance and RTS rates in professional baseball players after ACLR.

Background: There are many risk factors for shoulder and elbow injuries in professional baseball pitchers. The elbow carrying angle has not been studied as a potential risk factor. Purpose/Hypothesis: The aim of this study was to determine whether elbow carrying angle is a risk factor for shoulder or elbow injuries in professional baseball pitchers. We hypothesized that pitchers with a higher elbow carrying angle would be less likely to sustain an injury during the season than pitchers with a lower elbow carrying angle. Study Design: Cohort study; Level of evidence, 2. Methods: All professional pitchers for a single baseball club during the 2018 season had the carrying angle of both elbows measured at spring training by a single examiner. The pitchers were followed prospectively throughout the season. Shoulder and elbow injuries were recorded prospectively. Results: A total of 52 pitchers (21 [40%] Major League Baseball and 31 [60%] Minor League Baseball) were included. During the season, 23 (44%) pitchers became injured. The mean carrying angle in the throwing arm was 12.5° ± 4.2° versus 9.9° ± 2.8° in the nonthrowing arm ( P < .001). Comparing the injured and noninjured groups, there were no differences in level of play ( P = .870), throwing hand dominance ( P = .683), batting hand dominance ( P = .554), throwing-side carrying angle ( P = .373), nonthrowing-side carrying angle ( P = .773), or side-to-side difference in carrying angle ( P = .481). Conclusion: The elbow carrying angle was not associated with an injury risk during a single season in professional baseball pitchers.