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Open Access Publications from the University of California

Open Access Policy Deposits

This series is automatically populated with publications deposited by UCSF Department of Orthopaedic Surgery researchers in accordance with the University of California’s open access policies. For more information see Open Access Policy Deposits and the UC Publication Management System.

Cover page of Effects of Early Sport Specialization on Injury Load Management and Athletic Success of National Basketball Association Players.

Effects of Early Sport Specialization on Injury Load Management and Athletic Success of National Basketball Association Players.

(2025)

Background

The effects of early sport specialization on professional athletes resilience in handling increased workloads and athletic success have not been fully described.

Hypothesis

National Basketball Association (NBA) players who were multisport athletes during high school would be able to withstand higher workloads with lower injury rates and have more athletic success compared with their single-sport peers.

Study design

Descriptive epidemiology study.

Methods

Included were first-round NBA draft picks from 2013 to 2023 who had played ≥1 game in their first 3 seasons after being drafted. Athletes who had participated in ≥1 high school sports in addition to basketball were classified as multisport athletes, while those who had only played basketball were classified as single-sport athletes. For each players first 3 NBA seasons, workload data (number of games played and distance traveled per game/season in meters), injury history, statistical performance (player efficiency rating), and end-of-season award history were collected through the official NBA advanced statistics database and through publicly available records.

Results

Overall, 318 athletes were included, of whom 87 (27.4%) were multisport and 231 (72.6%) were single-sport. During their first 3 seasons combined, multisport athletes played in significantly more games (148.9 ± 67.1 vs 125.8 ± 63.8; P < .01), traveled greater total distances (133,183.9 ± 239,923.0 m vs 73,879.5 ± 165,093.9 m; P < .01), and had a significantly lower percentage of games missed due to injury (13.5% vs 16.9%; P < .001) compared with single-sport athletes. There was a significant correlation between increased workload (total distance traveled) and number of injuries in single-sport athletes (ρ = 0.37; P < .001) but not in multisport athletes (ρ = 0.14; P = .20). Last, multisport players had a significantly higher player efficiency rating (12.8 ± 11.6 vs 10.5 ± 5.1; P < .05) and award achievement likelihood (40.2% vs 19.0%; P < .001).

Conclusion

NBA players who had participated in multiple sports during high school demonstrated an ability to withstand higher workloads while having fewer games missed due to injury when compared with players who had only played basketball. Furthermore, athletes who delayed sport specialization had greater statistical and award success in their professional careers than those who focused on early single-sport specialization.

Cover page of Humeral Stem Design in Reverse Total Shoulder Arthroplasty.

Humeral Stem Design in Reverse Total Shoulder Arthroplasty.

(2024)

PURPOSE OF THE REVIEW: There have been tremendous modifications to the humeral component since Paul Grammont first introduced the reverse total shoulder arthroplasty in 1985. The purpose of this article is to review historical design features and their drawbacks and to summarize the clinical outcomes of modern designs. RECENT FINDINGS: Decreasing the neck-shaft angle and increasing humeral lateralization have helped address problems of scapular notching and limited internal and external rotation that were common with traditional designs. Advancements in proximal porous coatings have also facilitated the development of short-stem and stemless implants, which decreases the need for cement fixation and allows preservation of bone stock. Moreover, a reduction in stem length with smaller metaphyseal and diaphyseal filling ratios may limit stress shielding. Current humeral implants have an aseptic loosening rate less than 1%. Despite promising results, many of these new humeral design features do not have long-term data and continued surveillance of their performance is necessary. The humeral stem design significantly influences clinical and radiographic outcomes. Surgeons should be mindful of these design variables to increase impingement-free range of motion, minimize scapular notching, reduce stress shielding, and improve implant survivorship.

Cover page of The Effect of Platelet Dose on Outcomes after Platelet Rich Plasma Injections for Musculoskeletal Conditions: A Systematic Review and Meta-Analysis

The Effect of Platelet Dose on Outcomes after Platelet Rich Plasma Injections for Musculoskeletal Conditions: A Systematic Review and Meta-Analysis

(2024)

Purpose of review

This study aims to systematically review platelet dosage in platelet rich plasma (PRP) injections for common musculoskeletal conditions.

Recent findings

Notable heterogeneity exists in the literature regarding platelet dosage. Clinical studies indicate that a higher dosage may lead to improved outcomes concerning pain relief, functional improvement, and chondroprotection in knee osteoarthritis (OA). However, the impact of dosing on other musculoskeletal pathologies remains uncertain. Our investigation identifies a potential dose-response relationship between platelet dose and PRP effectiveness for knee OA treatment, pinpointing an optimal threshold of greater than 10 billion platelets for favorable clinical outcomes. Notably, this effect appears more pronounced for functional outcomes than for pain relief. For other conditions, a lower dosage may suffice, although the existing literature lacks clarity on this matter. PRP dosage may significantly influence treatmentoutcomes, particularly in knee OA. Further research is warranted to elucidate optimal dosages for varying conditions.

Cover page of The Condition of the Meniscus and Cartilage of the Injured Knee on Preoperative Magnetic Resonance Imaging Is a Prognostic Factor Affecting Postoperative Outcomes Following Knee Cartilage Restoration Surgery.

The Condition of the Meniscus and Cartilage of the Injured Knee on Preoperative Magnetic Resonance Imaging Is a Prognostic Factor Affecting Postoperative Outcomes Following Knee Cartilage Restoration Surgery.

(2024)

PURPOSE: To evaluate the relationship between preoperative whole-joint imaging evaluation of the knee with patient-reported outcome (PRO) measures after cartilage restoration surgery (mosaicplasty, osteochondral allograft transplantation, matrix autologous chondrocyte implantation). METHODS: We retrospectively evaluated patients who underwent knee articular cartilage restoration at our institution from 2014 to 2020. The patients knee magnetic resonance imaging (MRI) was evaluated with the Whole-Organ Magnetic Resonance Imaging Score (WORMS) and semiquantitative synovial inflammation imaging biomarkers of the preoperative MRI. To assess PRO score, Lysholm score and Knee injury and Osteoarthritis Outcome Score were completed at a minimum 2-year follow-up. Statistical analysis was performed using the Spearman rank test to obtain correlation values for WORMS score and PRO score for each survey. RESULTS: Forty patients were enrolled in this study. The average age at baseline was 34.5 years. The average body mass index was 28.2, and 26 of 40 were men (age range, 20-58 years). The maximum preoperative WORMS score was significantly correlated with the postoperative Lysholm score (r = -0.52, P = .0013). The WORMS Meniscus and Cartilage subscales were significantly correlated with the Lysholm score (r = -0.36, P = .024 and r = -0.37, P = .021, respectively). The maximum WORMS score was significantly correlated with the Knee injury and Osteoarthritis Outcome Score daily living and sports/recreation subscores (r = -0.47, P = .0023 and r = -0.42, P = .0077, respectively). Semiquantitative synovial inflammation imaging biomarkers were not significantly correlated with PRO scores. CONCLUSIONS: Increasing preoperative degenerative change in the knee, as evidenced by a higher WORMS on preoperative MRI, was associated with inferior patient-reported outcomes at a minimum of 2 years after cartilage restoration surgery (mosaicplasty, osteochondral allograft transplantation, matrix autologous chondrocyte implantation). Semiquantitative scoring of the whole joint on preoperative MRI may allow for improved counseling regarding expected benefit for patients after cartilage restoration surgery. LEVEL OF EVIDENCE: Level IV, prognostic case series.

Cover page of Independent Prognostic Factors Associated With Improved Patient-Reported Outcomes in the Prospective Evaluation of Elderly Deformity Surgery (PEEDS) Study.

Independent Prognostic Factors Associated With Improved Patient-Reported Outcomes in the Prospective Evaluation of Elderly Deformity Surgery (PEEDS) Study.

(2024)

STUDY DESIGN: Prospective, multicenter, international, observational study. OBJECTIVE: Identify independent prognostic factors associated with achieving the minimal clinically important difference (MCID) in patient reported outcome measures (PROMs) among adult spinal deformity (ASD) patients ≥60 years of age undergoing primary reconstructive surgery. METHODS: Patients ≥60 years undergoing primary spinal deformity surgery having ≥5 levels fused were recruited for this study. Three approaches were used to assess MCID: (1) absolute change:0.5 point increase in the SRS-22r sub-total score/0.18 point increase in the EQ-5D index; (2) relative change: 15% increase in the SRS-22r sub-total/EQ-5D index; (3) relative change with a cut-off in the outcome at baseline: similar to the relative change with an imposed baseline score of ≤3.2/0.7 for the SRS-22r/EQ-5D, respectively. RESULTS: 171 patients completed the SRS-22r and 170 patients completed the EQ-5D at baseline and at 2 years postoperative. Patients who reached MCID in the SRS-22r self-reported more pain and worse health at baseline in both approaches (1) and (2). Lower baseline PROMs ((1) - OR: .01 [.00-.12]; (2)- OR: .00 [.00-.07]) and number of severe adverse events (AEs) ((1) - OR: .48 [.28-.82]; (2)- OR: .39 [.23-.69]) were the only identified risk factors. Patients who reached MCID in the EQ-5D demonstrated similar characteristics regarding pain and health at baseline as the SRS-22r using approaches (1) and (2). Higher baseline ODI ((1) - OR: 1.05 [1.02-1.07]) and number of severe AEs (OR: .58 [.38-.89]) were identified as predictive variables. Patients who reached MCID in the SRS22r experienced worse health at baseline using approach (3). The number of AEs (OR: .44 [.25-.77]) and baseline PROMs (OR: .01 [.00-.22] were the only identified predictive factors. Patients who reached MCID in the EQ-5D experienced less AEs and a lower number of actions taken due to the occurrence of AEs using approach (3). The number of actions taken due to AEs (OR: .50 [.35-.73]) was found to be the only predictive variable factor. No surgical, clinical, or radiographic variables were identified as risk factors using either of the aforementioned approaches. CONCLUSION: In this large multicenter prospective cohort of elderly patients undergoing primary reconstructive surgery for ASD, baseline health status, AEs, and severity of AEs were predictive of reaching MCID. No clinical, radiological, or surgical parameters were identified as factors that can be prognostic for reaching MCID.

Cover page of Patient Expectations and Satisfaction in Pediatric Orthopedics.

Patient Expectations and Satisfaction in Pediatric Orthopedics.

(2024)

PURPOSE OF REVIEW: The purpose of the current review is to analyze the current literature regarding the tools available to evaluate patient expectations and satisfaction. There have been an increasing number of tools that have been developed and validated for various orthopedic procedures. Despite the growing number of tools, there are a limited number of tools available for pediatric patients. RECENT FINDINGS: Several tools have been developed in orthopedics to evaluate patient expectations. However, there are no tools that have been validated in the pediatric population. In addition, pediatric patient expectations should be collected in conjunction with parent/caregiver expectations. Although not specifically validated for pediatric patients, there are several tools available that may pertain to pediatric patients including the HSS ACL Expectations Survey, HSS Shoulder Expectations Survey, HSS Knee Surgery Expectations Survey, HSS Foot and Ankle Surgery Expectation Survey, Sunnybrook Surgery Expectations Survey, Musculoskeletal Outcomes Data Evaluation and Management System (MODEMS) Instruments, Quick DASH, and DASH. In terms of patient satisfaction, there are even fewer tools available. Several tools have been developed to evaluate patient satisfaction and five additional tools within orthopedics. Of these tools, there are two that have been validated for pediatric patients: The Swedish Parents Satisfaction Questionnaire and the Scoliosis Research Society-22. There are a growing number of tools to evaluate patients expectations and satisfaction in the orthopedic literature. Given most of these tools pertain to adult patients, there is a need for further development of tools specifically validated for pediatric patients and their parents/caregivers. Through the measurement of expectations and satisfaction, medical professionals can hope to improve satisfaction and outcomes.

Cover page of Effects of pelvic fixation strategies and multi-rod constructs on biomechanics of the proximal junction in long thoracolumbar posterior instrumented fusions: a finite-element analysis.

Effects of pelvic fixation strategies and multi-rod constructs on biomechanics of the proximal junction in long thoracolumbar posterior instrumented fusions: a finite-element analysis.

(2024)

PURPOSE: To assess the effect of various pelvic fixation techniques and number of rods on biomechanics of the proximal junction of long thoracolumbar posterior instrumented fusions. METHODS: A validated spinopelvic finite-element (FE) model was instrumented with L5-S1 ALIF and one of the following 9 posterior instrumentation configurations: (A) one traditional iliac screw bilaterally (2 Iliac/2 Rods); (B) T10 to S1 (Sacral Only); (C) unilateral traditional iliac screw (1 Iliac/2 Rods); (D) one traditional iliac screw bilaterally with one midline accessory rod (2 Iliac/3 rods); (E) S2AI screws connected directly to the midline rods (2 S2AI/2 Rods); and two traditional iliac screws bilaterally with two lateral accessory rods connected to the main rods at varying locations (F1: T10-11, F2: T11-12, F3: T12-L1, F4: L1-2) (4 Iliac/4 Rods). Range of motions (ROM) at T10-S1 and T9-T10 were recorded and compared between models. The T9-T10 intradiscal pressures and stresses of the T9-10 discs annulus in addition to the von Mises stresses of the T9 and T10 vertebral bodies were recorded and compared. RESULTS: For T10-S1 ROM, 4 iliac/4 rods had lowest ROM in flexion and extension, while 2 S2AI/2 rods showed lowest ROM in rotation. Constructs with 3 or 4 rods had lower stresses on the primary rods compared to 2-rod constructs. At the proximal adjacent disc (T9-10), 4 iliac/4 rods showed lowest ROM, lowest intradiscal pressures, and lowest annular stress in all directions (most pronounced in flexion-extension). Under flexion and extension, 4 iliac/4 rods also showed the lowest von Mises stresses on the T10 vertebral body but the highest stresses on the T9 vertebral body. CONCLUSIONS: Dual iliac screws with 4 rods across the lumbosacral junction and extending to the thoracolumbar junction demonstrated the lowest T10-S1 ROM, the lowest adjacent segment disc (T9-T10) ROM, intradiscal pressures, and annular stresses, and the lowest UIV stresses, albeit with the highest UIV + 1 stresses. Additional studies are needed to confirm whether these biomechanical findings dictate clinical outcomes and effect rates of proximal junctional kyphosis and failure.

Cover page of Association Between Tibiofemoral Bone Shape Features and Retears After Anterior Cruciate Ligament Reconstruction.

Association Between Tibiofemoral Bone Shape Features and Retears After Anterior Cruciate Ligament Reconstruction.

(2024)

BACKGROUND: A retear after anterior cruciate ligament (ACL) reconstruction remains a common and devastating complication. Knee bone morphology is associated with the risk of ACL injuries, ACL retears, and osteoarthritis, and a combination of tools that derive bone shape from clinical imaging, such as magnetic resonance imaging (MRI) and statistical shape modeling, could identify patients at risk of developing these joint conditions. PURPOSE: To identify bone shape features before primary ACL reconstruction in patients with an eventual retear compared to those with a known intact ACL graft. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Bone was automatically segmented on 2-dimensional proton density-weighted MRI of the knee in patients at the time of the initial ACL injury using deep convolutional neural networks. Patients with a subsequent retear after reconstruction within 3 years (22 femurs, 19 tibias) were compared with those with an intact ACL graft at 3 years (20 femurs, 22 tibias) using statistical shape modeling to identify preoperative bone shape features predictive of a retear after ACL reconstruction. RESULTS: Statistical shape modeling revealed 2 specific bone shape features (modes) in the femur and 1 mode in the tibia that demonstrated significant differences at the time of the initial injury in patients with subsequent retears. In the femur, a narrower intercondylar notch width, a widened medial condylar width, an increased femoral condylar offset ratio, increased surface area along the lateral femoral condyle relative to the medial condyle, and a more prominent trochlear sulcus at the time of the initial injury were associated with retears after ACL reconstruction. In the tibia, a diminished ACL facet prominence, a squared lateral and medial tibial plateaus, and a broader and flattened tibial spine at the time of the initial injury were associated with retears after ACL reconstruction. CONCLUSION: Using the automatic bone segmentation pipeline on preoperative MRI, the authors identified bone shape features associated with a retear after ACL reconstruction. The use of this pipeline enables large-scale studies of bone shape on MRI and could predict patients at risk of ACL retears to alter treatment decisions.

Cover page of Improving rigor and reproducibility in western blot experiments with the blotRig analysis.

Improving rigor and reproducibility in western blot experiments with the blotRig analysis.

(2024)

Western blot is a popular biomolecular analysis method for measuring the relative quantities of independent proteins in complex biological samples. However, variability in quantitative western blot data analysis poses a challenge in designing reproducible experiments. The lack of rigorous quantitative approaches in current western blot statistical methodology may result in irreproducible inferences. Here we describe best practices for the design and analysis of western blot experiments, with examples and demonstrations of how different analytical approaches can lead to widely varying outcomes. To facilitate best practices, we have developed the blotRig tool for designing and analyzing western blot experiments to improve their rigor and reproducibility. The blotRig application includes functions for counterbalancing experimental design by lane position, batch management across gels, and analytics with covariates and random effects.

Cover page of The Predictors of Surgery for Symptomatic, Atraumatic Full-Thickness Rotator Cuff Tears Change Over Time: Ten-Year Outcomes of the MOON Shoulder Prospective Cohort.

The Predictors of Surgery for Symptomatic, Atraumatic Full-Thickness Rotator Cuff Tears Change Over Time: Ten-Year Outcomes of the MOON Shoulder Prospective Cohort.

(2024)

BACKGROUND: A prospective cohort study was conducted to assess the predictors of failure of nonoperative treatment, defined as the patient undergoing surgery for symptomatic, atraumatic full-thickness rotator cuff tears. We present the 10-year follow-up data of this population to determine if predictors for surgery change over time, and secondarily we report the outcomes of the cohort. METHODS: At the time of enrollment, demographic, symptom, rotator cuff anatomy, and patient-reported outcome data were collected in patients with symptomatic, atraumatic full-thickness rotator cuff tears. Patients underwent a standard physical therapy protocol for 6 to 12 weeks. Patient data were then collected at 1, 2, 5, 7, and 10 years. Failure of nonoperative treatment was defined as the patient electing to undergo surgery. RESULTS: Of the 452 patients in the original cohort, 20 patients (5%) withdrew from the study, 37 (9%) died before 10 years, and 40 (9%) were otherwise lost to follow-up. A total of 115 patients (27.0%) underwent a surgical procedure at some point during the 10-year follow-up period. Of these patients, 56.5% underwent surgery within 6 months of enrollment and 43.5%, between 6 months and 10 years. Low patient expectations regarding the efficacy of physical therapy were found to be a predictor of early surgery. Workers Compensation status and activity level were more important predictors of later surgery. Patient-reported outcome measures all improved following physical therapy. For patients who did not undergo a surgical procedure, patient-reported outcome measures did not decline over the 10-year follow-up period. CONCLUSIONS: Low patient expectations regarding the efficacy of physical therapy were found to be a predictor of early surgery, whereas Workers Compensation status and activity level were predictors of later surgery. Physical therapy was successful in >70% of patients with symptomatic, atraumatic full-thickness rotator cuff tears at 10 years. Outcome measures improved with physical therapy and did not decline over the 10-year follow-up period. LEVEL OF EVIDENCE: Prognostic Level I . See Instructions for Authors for a complete description of levels of evidence.