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Purpose To develop a nondestructive method of measuring distal radioulnar joint (DRUJ) joint reaction force (JRF) that preserves all periarticular soft tissues and more accurately reflects in vivo conditions. Methods Eight fresh-frozen human cadaveric limbs were obtained. A threaded Steinmann pin was placed in the middle of the lateral side of the distal radius transverse to the DRUJ. A second pin was placed into the middle of the medial side of the distal ulna colinear to the distal radial pin. Specimens were mounted onto a tensile testing machine using a custom fixture. A uniaxial distracting force was applied across the DRUJ while force and displacement were simultaneously measured. Force-displacement curves were generated and a best-fit polynomial was solved to determine JRF. Results All force-displacement curves demonstrated an initial high slope where relatively large forces were required to distract the joint. This ended with an inflection point followed by a linear area with a low slope, where small increases in force generated larger amounts of distraction. Each sample was measured 3 times and there was high reproducibility between repeated measurements. The average baseline DRUJ JRF was 7.5 N (n = 8). Conclusions This study describes a reproducible method of measuring DRUJ reaction forces that preserves all periarticular stabilizing structures. This technique of JRF measurement may also be suited for applications in the small joints of the wrist and hand. Clinical relevance Changes in JRF can alter native joint mechanics and lead to pathology. Reliable methods of measuring these forces are important for determining how pathology and surgical interventions affect joint biomechanics.

Introduction: Division chiefs (DCs) play an integral role within the department, making critical decisions and helping shape the future of both the division and the department. This study aimed to investigate the demographic characteristics and scholarly work of DCs in academic orthopaedic sports medicine division in the United States. Methods: Orthopaedic residency programs at academic centers were identified using the Association of American Medical Colleges' Electronic Residency Application Service. DCs were identified using the program's respective websites where data points such as sex, race/ethnicity, fellowship training institution, time since graduating fellowship, academic rank, number of degrees, and additional leadership titles were collected. Scopus database was used to determine h-indices. Results: From the 191 programs identified, 100 had a DC for the sports medicine subspecialty division, and 66 programs offered a sports medicine fellowship. Most DCs (96%) were men. The racial/ethnic demographics of the DCs were mostly White (86%), followed by Asian (11%), African American (1%), Hispanic/Latino (1%), and mixed ethnicity (1%). On average, the DCs were 19.6 years past their fellowship completion. The average h-index was 21.2. Many (48%) had an academic rank of professor, 28% associate professor, and 12% assistant professor. Four held additional graduate degrees. The fellowship programs that trained the most DCs were Hospital for Special Surgery (11), Kerlan Jobe Orthopaedic Clinic (8), University of Pittsburgh (7), American Sports Medicine Institution (5), Cleveland Clinic (5), Cincinnati Sports Medicine (4), Massachusetts General Hospital (4), and Steadman Hawkins Clinic (4). Discussion: DCs in academic orthopaedic surgery plays a crucial role in the department and is a topic that is understudied. A lack of diversity exists among DCs in academic Sports Medicine in orthopaedics. The position is held predominately by White men with a rank of either full or associate professor and extensive leadership experience. More efforts are needed to increase the diversity of sports medicine leadership within academic orthopaedic programs in the United States.

Spinal fusion is a commonly performed orthopedic surgery. Autologous bone graft obtained from the iliac crest is frequently employed to perform spinal fusion. Osteogenic bone marrow stromal (a.k.a. mesenchymal stem) cells (BMSCs) are believed to be responsible for new bone formation and development of the bridging bone during spinal fusion, as these cells are located in both the graft and at the site of fusion. Our previous work revealed the importance of mitochondrial oxidative metabolism in osteogenic differentiation of BMSCs. Our objective here was to determine the impact of BMSC oxidative metabolism on osseointegration of the graft during spinal fusion. The first part of the study was focused on correlating oxidative metabolism in bone graft BMSCs to radiographic outcomes of spinal fusion in human patients. The second part of the study was focused on mechanistically proving the role of BMSC oxidative metabolism in osseointegration during spinal fusion using a genetic mouse model. Patients’ iliac crest-derived graft BMSCs were identified by surface markers. Mitochondrial oxidative function was detected in BMSCs with the potentiometric probe, CMXRos. Spinal fusion radiographic outcomes, determined by the Lenke grade, were correlated to CMXRos signal in BMSCs. A genetic model of high oxidative metabolism, cyclophilin D knockout (CypD KO), was used to perform spinal fusion in mice. Graft osseointegration in mice was assessed with micro-computed tomography. Our study revealed that higher CMXRos signal in patients’ BMSCs correlated with a higher Lenke grade. Mice with higher oxidative metabolism (CypD KO) had greater mineralization of the spinal fusion bridge, as compared to the control mice. We therefore conclude that higher oxidative metabolism in BMSCs correlates with better spinal fusion outcomes in both human patients and in a mouse model. Altogether, our study suggests that promoting oxidative metabolism in osteogenic cells could improve spinal fusion outcomes for patients.

Purpose To compare how ulnar diaphyseal shortening and wafer resection affect distal radioulnar joint (DRUJ) joint reaction force (JRF) using a nondestructive method of measurement. Our hypothesis was that ulnar shortening osteotomy would increase DRUJ JRF more than wafer resection. Methods Eight fresh-frozen human cadaveric upper limbs were obtained. Under fluoroscopic guidance, a threaded pin was inserted into the lateral radius orthogonal to the DRUJ and a second pin was placed in the medial ulna coaxial to the radial pin. Each limb was mounted onto a mechanical tensile testing machine and a distracting force was applied across the DRUJ while force and displacement were simultaneously measured. Data sets were entered into a computer and a polynomial was generated and solved to determine the JRF. This process was repeated after ulnar diaphyseal osteotomy, ulnar re-lengthening, and ulnar wafer resection. The JRF was compared among the 4 conditions. Results Average baseline DRUJ JRF for the 8 arms increased significantly after diaphyseal ulnar shortening osteotomy (7.2 vs 10.3 N). Average JRF after re-lengthening the ulna and wafer resection was 6.9 and 6.7 N, respectively. There were no differences in JRF among baseline, relengthened, and wafer resection conditions. Conclusions Distal radioulnar joint JRF increased significantly after ulnar diaphyseal shortening osteotomy and did not increase after ulnar wafer resection. Clinical relevance Diaphyseal ulnar shortening osteotomy increases DRUJ JRF, which may lead to DRUJ arthrosis.

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Study Design. Retrospective cross-sectional analysis.Objective. The aim of this study was to establish the strength of relationship between the Patient-reported Outcomes Measurement Information System (PROMIS) Adult Depression (AD), Physical Function (PF), and Pain Interference (PI) with the Swiss Spinal Stenosis Questionnaire (SSSQ) in assessing lumbar spinal stenosis (LSS). Summary of Background Data. In 2009, there were >35,000 surgeries for LSS, which amounted to $1.65 billion in health care cost. By 2021, there will be >2.4 million people in the United States with symptomatic LSS. There is an increasing emphasis on patient-reported outcomes (PROs) to define value in medicine. Therefore, it would be beneficial to compare PROMIS, a universal PRO, against the SSSQ, the ''criterion standard'' for assessing LSS. Methods. Eighty-two patients with LSS completing the PROMIS and SSSQ were enrolled. Per existing institutional protocol, PROMIS AD, PF, and PI were completed at every clinic visit. Linear regression analysis was then performed to evaluate how well the SSSQ and PROMIS scores correlated to each other. Results. When linear regression was performed for pretreatment values, the R 2 value for the SSSQ PF versus PROMIS PF was 0.14 (P ¼ 0.0008), whereas the R 2 value for the SSSQ symptom severity versus PROMIS PI was 0.03 (P ¼ 0.13). The R 2 value for the combined SSSQ physical function and symptom severity versus PROMIS AD was 0.07 (P ¼ 0.02). When post-treatment SSSQ satisfaction scores were correlated to postoperative PROMIS AD, PI, and PF scores, the R 2 values for a good linear fit were 0.13, 0.25, and 0.18 respectively (P values: 0.01, 0.003, and 0.003). Conclusion. Pre-treatment PROMIS scores do not adequately capture the disease-specific impact of spinal stenosis, but postoperative PROMIS scores better reflect outcomes after surgery for LSS. PROMIS scores should not be used in isolation to assess outcomes in patients with LSS.

We identified the major structures at risk when performing the proximal medial gastrocnemius release and propose a novel, possibly safer alternative for the medial gastrocnemius release.