Stephen F. Brockmeier

Context : Following ACL reconstruction (ACLR) arthrogenic muscle inhibition limits quadriceps function. Arthrogenic muscle inhibition is characterized via a decreased central activation ratio and a higher active motor threshold. Although previous research has identified reductions in the torque–velocity relationship post-ACLR, our aim was to determine if this relationship is associated with measures of arthrogenic muscle inhibition following ACLR. Design : Cross-sectional. Methods : Nine participants (5 females and 4 males; 175.8 [7.8] cm, 79.4 [14.2] kg, 20.6 [28.8] mo postsurgery) following ACLR and 24 control participants (20 females and 4 males; 167.6 [8.1] cm, 66.9 [13.3] kg) completed isokinetic knee extension at 60, 90, 180, and 270°/s. A superimposed burst was delivered during maximal volitional isometric contraction using a square-wave stimulator to obtain central activation ratio. Transcranial magnetic stimulation was applied to obtain active motor threshold in ACLR involved limbs and control limbs. Correlations between 2-point torque–velocity relationships, central activation ratio, and active motor thresholds were analyzed separately by group with a false discovery rate correction applied. Results : The ACLR central activation ratio was not correlated with the torque–velocity relationship, but the control central activation ratio positively correlated with multiple 2-point torque–velocity relationships ( q < 0.05). The active motor threshold was higher in the ACLR participants (ACLR: 34.8 [7.8], control: 27.5 [9.4]). In the ACLR, the limbs active motor threshold was not correlated with torque–velocity relationships, but the control limb active motor threshold was correlated with T:V _60-0 ( r = .52, P < .001, q = 0.02); T:V _90-0 ( r = .47, P < .002, q = 0.024); T:V _180-0 ( r = .34, P = .04, q = 0.048); T:V _270-0 ( r = .37, P = .03, q = 0.045); and T:V _180-60 ( r = .41, P = .013, q = 0.037). Conclusion : Two-point torque–velocity relationships incorporating isometric contractions were associated with both voluntary activation and corticospinal excitability in healthy participants but not in ACLR limbs.

Introduction: Fellowship directors (FD) in sports medicine are distinguished leaders and mentors of trainees. There is little literature available regarding their demographics and unique factors and training that have allowed them to rise to their prominent positions. The goal of this study was to identify FDs' demographics, research output, and education with an emphasis on surveying the diversity in these leadership positions. Methods: The Accreditation Council for Graduate Medical Education Public Accreditation Data System was used to identify all accredited and active orthopaedic sports medicine fellowship positions for 2019 to 2020. Primary data points for the FDs included race/ethnicity, age, sex, residency and fellowship training institutions, year of fellowship completion, year of hire at the current institution, year of FD appointment, and H-index. Student t-tests were used to compare FDs who trained at their current institution versus those who did not. Significance was set at P < 0.05. Results: The 87 active sports medicine fellowship programs surveyed were led by 86 FDs and 2 co-FDs. One (1.1%) FD was female, whereas 87 (98.9%) were male. The mean age of the 88 total FDs was 54.5 years (n = 81). FDs were predominantly White (n = 75, 85.2%), followed by Asian American (n = 6, 6.8%), African American (n = 3, 3.4%), Middle Eastern (n = 3, 3.4%), and then Hispanic/Latino (n = 1, 1.1%). Certain associations were observed between FDs' residency and fellowship and future leadership positions. The most frequently reported training locations were Hospital for Special Surgery (residency, N = 10) and the Steadman Clinic (Vail) (fellowship, N = 10). The mean H-index was 22.33 ± 16.88, and FDs leading the fellowship where they trained had significantly lower mean H-indices than FDs who were not (12.57 ± 12.57 versus 24.85 ± 17.56, respectively) (P = 0.02). Conclusion: More diversity is possible among sports medicine FDs, who are prominent leaders. Moreover, certain programs are associated with producing a greater number of FDs.

Background: Stemless humeral components for anatomic total shoulder arthroplasty (aTSA) have several reported potential benefits compared with stemmed implants. However, we are aware of no Level-I, randomized controlled trials (RCTs) that have compared stemless implants with stemmed implants in patients managed with aTSA. We sought to directly compare the short-term clinical and radiographic outcomes of stemless and stemmed implants to determine if the stemless implant is noninferior to the stemmed implant. Methods: We performed a prospective, multicenter, single-blinded RCT comparing stemless and short-stemmed implants in patients managed with aTSA. Range-of-motion measurements and American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and Constant scores were obtained at multiple time points. Device-related complications were recorded. Radiographic evaluation for evidence of loosening, fractures, dislocation, or other component complications was performed. Statistical analysis for noninferiority was performed at 2 years of follow-up for 3 primary end points: ASES score, absence of device-related complications, and radiographic signs of loosening. All other data were compared between cohorts at all time points as secondary measures. Results: Two hundred and sixty-five shoulders (including 176 shoulders in male patients and 89 shoulders in female patients) were randomized and received the allocated treatment. The mean age of the patients (and standard deviation) was 62.6 ± 9.3 years, and 99% of the shoulders had a primary diagnosis of osteoarthritis. At 2 years, the mean ASES score was 92.5 ± 14.9 for the stemless cohort and 92.2 ± 13.5 for the stemmed cohort (p value for noninferiority test, <0.0001), the proportion of shoulders without device-related complications was 92% (107 of 116) for the stemless cohort and 93% (114 of 123) for the stemmed cohort (p value for noninferiority test, 0.0063), and no shoulder in either cohort had radiographic signs of loosening. Range-of-motion measurements and ASES, SANE, and Constant scores did not differ significantly between cohorts at any time point within the 2-year follow-up. Conclusions: At 2 years of follow-up, the safety and effectiveness of the stemless humeral implant were noninferior to those of the stemmed humeral implant in patients managed with aTSA for the treatment of osteoarthritis. These short-term results are promising given the potential benefits of stemless designs over traditional, stemmed humeral components. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.