Joseph A. Buckwalter

Introduction: Ulnar variance is a radiographic measurement that describes the relative heights of the distal ulna and radius. Youth athletes who repetitively load their wrist can develop stress injury at the distal radial physis, which may alter longitudinal growth resulting in positive ulnar variance (PUV). This dynamic bony relationship may predilect athletes for wrist pain and/or ulnar-sided pathology; however, the prevalence and clinical significance of ulnar variance in youth athletes is not completely understood. Sources of data: PubMed, CINAHL, EMBASE, and SPORTDiscus were queried in November 2025 without time constraints. Areas of agreement: Ulnar variance is best measured in skeletally immature athletes on posteroanterior radiographs using Hafner’s method. Youth athletes exhibit more PUV values on average than non-athlete predicted norms. Its magnitude is not significantly associated with training volume or wrist pain. Positive ulnar variance is a potential end stage of stress injury to the radial growth plate complex. Symptomatic PUV becomes clinically meaningful and may warrant surgical intervention in select cases. Areas of controversy: Reported prevalence of PUV in youth athletes varies widely across studies (0%–50%), reflecting substantial heterogeneity in the existing literature. Inconsistent associations of ulnar variance with multiple anthropometric variables, biological data, and training characteristics prevent clear delineation between the effects of genetics vs repetitive mechanical stress to the distal radial physis on its development. Treatment of symptomatic PUV remains controversial. Growing points: Body composition may uniquely impact ulnar variance magnitude. Distal radial physis stress injury, rather than PUV, may be a primary driver of wrist pain. Areas timely for developing research: Newer prospective investigations incorporating dynamic imaging techniques are warranted to evaluate ulnar variance under physiologic weight-bearing conditions. Future work should include athletes from multiple upper extremity weight-bearing sports (gymnastics, cheerleading, diving, and wrestling) across all levels of participation to better account for the effects of training exposure on ulnar variance. Serial radiographic evaluation may also help define the relationship between progressive PUV and the development of wrist pain and dysfunction.

Background: Treatment of compressive neuropathies in diabetic patients remains controversial, with variable functional outcomes reported. This study is aimed at establishing a rat model of diabetic nerve compression that is suitable for investigations of diabetic nerve recovery after surgical decompression. Methods: Twenty male Zucker diabetic fatty obese (diabetic) and 20 lean (nondiabetic) rats underwent surgery to compress the sciatic nerve using a polymer sleeve or sham surgery. Six weeks later, decompression surgery or second sham surgery was performed. Nerve conduction velocities (NCV) and nociception via von Frey filaments (vF) were monitored weekly. Histological measures of nerve structure were compared between groups after 6 weeks of compression and 6 weeks after surgical decompression. Results: Both diabetic and nondiabetic compressed nerves had significant reductions in NCV immediately postoperatively ( p < 0.001) and progressive reductions in vF threshold during the compression period ( p ≤ 0.002). After decompression, vF threshold and NCV increased; however, nerve function did not return to baseline or sham control values in either compressed group. Six weeks of compression significantly reduced axon size ( p < 0.001) and myelin thickness ( p = 0.014) in nondiabetic nerves but minimally changed the histological appearance of diabetic nerves. Decompression of nondiabetic nerves increased axon numbers ( p = 0.005) but did not affect myelin thickness. In diabetic nerves, decompression also increased axon numbers, whereas myelin thickness decreased ( p = 0.022) to levels similar to nondiabetic nerves. Conclusions: The histological response of nondiabetic nerves to compression and decompression was more pronounced than the functional response. Diabetic nerves showed a similar reaction to nondiabetic nerves but at a slower rate.

For decades, surgeons have utilized 0.9% normal saline (NS) for joint irrigation to improve visualization during arthroscopic procedures. This continues despite mounting evidence that NS exposure impairs chondrocyte metabolism and compromises articular cartilage function. We hypothesized that chondrocyte oxidative stress induced by low pH is the dominant factor driving NS toxicity, and that buffering NS to increase its pH would mitigate these effects. Effects on chondrocyte viability, reactive oxygen species (ROS) production, and overall metabolic function were assessed. Even brief exposure to NS caused cell death, ROS overproduction, and disruption of glycolysis, pentose phosphate, and tricarboxylic acid (TCA) cycle pathways. NS also stimulated ROS overproduction in synovial cells that could adversely alter the synovial function and subsequently the entire joint health. Buffering NS with 25 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) significantly increased chondrocyte viability, reduced ROS production, and returned metabolite levels to near control levels while also reducing ROS production in synovial cells. These results confirm that chondrocytes and synoviocytes are vulnerable to insult from the acidic pH of NS and demonstrate that adding a buffering agent to NS averts many of its most harmful effects.

Context: Ulnar variance (UV) is a measurement of the relative locations of the radius and ulna that may become perturbed in athletic populations. Positive UV can be associated with wrist pathologies often treated conservatively or surgically and may result in interruption of sports participation. Objective: This scoping review aims to summarize diagnostic measures of UV in athletes, describe its relation to separate wrist conditions, and present treatment strategies for symptomatic UV. Data Sources: A systematic search was created and modified for PubMed, CINAHL, Embase, and SPORTDiscus including articles from inception until February 2, 2022. Study Selection: Articles including UV characterization, imaging modality style, and an athletic population were searched across multiple databases. Study Design: A scoping review was designed to identify the methods for imaging UV in athletic populations following the PRISMA Extension for Scoping Reviews (PRISMA-ScR). Level of Evidence: Level 4. Data Extraction: The specific athletic population, imaging modality, measurement style, wrist pathology association, and surgical management of UV were extracted. Results: A total of 4321 records were screened independently for eligibility: 22 met inclusion criteria. Eight sports comprised the analysis. All studies referenced conventional radiography to diagnose UV; 50% specified the posteroanterior, 18.2% anteroposterior, and 13.6% pronated, gripping radiographs. Hafner’s method (7×), Palmer’s technique (2×), and the method of perpendiculars (3×) were used to measure UV. Athletes displayed more positive UV than nonathletes and UV became more positive over time in longitudinal studies. Triangular fibrocartilage complex tears, focal lunate necrosis, and ulnar abutment were associated with positive UV. Ulnar shortening osteotomy was the most performed operation for positive UV. Conclusion: Conventional radiography is the gold standard for imaging UV in athletes. Hafner’s method is the most commonly used radiograph measurement technique. Wrist pathology in athletic populations may indicate positive UV in need for operative management.

Orthopaedic surgeons debate the timing of and necessity for surgical intervention when treating displaced midshaft clavicle fractures (MCFs). This systematic review evaluates the available literature regarding functional outcomes, complication rates, nonunion, and reoperation rates between patients undergoing early versus delayed surgical management of MCFs. Search strategies were applied in PubMed (Medline), CINAHL (EBSCO), Embase (Elsevier), Sport Discus (EBSCO), and Cochrane Central Register of Controlled Trials (Wiley). Following an initial screening and full-text review, demographic and study outcome data was extracted for comparison between the early fixation and delayed fixation studies. Twenty-one studies were identified for inclusion. This resulted in 1158 patients in the early group and 44 in the delayed. Demographics were similar between groups except for a higher percentage of males in the early group (81.6% vs. 61.4%) and longer time to surgery in the delayed group (4.6 days vs. 14.5 months). Disability of the arm, shoulder, and hand scores (3.6 vs. 13.0) and Constant-Murley scores (94.0 vs. 86.0) were better in the early group. Percentages of initial surgeries resulting in complication (33.8% vs. 63.6%), nonunion (1.2% vs. 11.4%), and nonroutine reoperation (15.8% vs. 34.1%) were higher in the delayed group. Outcomes of nonunion, reoperation, complications, DASH scores, and CM scores favor early surgery over delayed surgery for MCFs. However, given the small cohort of delayed patients who still achieved moderate outcomes, we recommend a shared decision-making style for treatment recommendations regarding individual patients with MCFs. Level of Evidence: II

To highlight the unique spectrum of lower extremity firearm injuries seen at a rural, Midwestern level 1 trauma center to provide insight into prevalence, mechanism of injury, and identify modifiable factors that contribute to firearm injuries of the lower extremity. It is our belief that the creation of our database will help future trauma and firearm databases improve documentation and understand the relationship between anatomic location of injury and outcomes. A retrospective review of lower extremity firearm injuries from a rural, Midwestern level 1 trauma center was collected from January 2011 to December 2019. Data acquired included injury description; demographics, injury mechanism/ description/ location, firearm used, toxicology, and information regarding hospitalization. Data was analyzed using Chi-squared analysis and Fisher's exact test for categorical data and the Wilcoxon rank sum test for continuous data. 69 patients with lower extremity firearm injuries were identified. Average age was 30.14 years, 89.86% were males, and one fatality were identified. 47.83% (33) of these injuries were assaults, followed by unintentional injuries at 42.03% (29). Law enforcement-related and self-inflicted injuries contributed minimally. Handguns were the most common type of firearm, used in 72.5% of cases. Nearly 1/3 of the unintentional firearm injuries occurred during November or December, the active deer hunting months in the community of study. The lower extremity is uniquely vulnerable to both assaults and unintentional injury in our rural environment, differing from what we have previously published regarding the upper extremity. Lower extremity gunshot wounds increased during the winter months, offering a correlation to deer hunting season. Our findings display that not all firearm injuries are created equal, and that there is a need to improve documentation of and additional study in order to optimally tailor firearm prevention measures based on the ruralityurbanicity spectrum. Level of Evidence: III.

Objectives: To determine if inclusion of an olecranon osteotomy to the posterior paratricipital approach for operative fixation of distal humerus fractures significantly affects surgical complication rates (OTA/AO 13). Design: Retrospective comparative cohort study. Setting: Level 1 trauma center. Patients/Participants: Three hundred four patients underwent open reduction internal fixation of a distal humerus fracture between 2007 and 2017. Of those, 134 met inclusion criteria (≥15 years, OTA/AO fracture type 13A, B, or C, and posterior surgical approach) for the study (n = 64 with olecranon osteotomy; n = 70 without olecranon osteotomy). Intervention: Open reduction internal fixation of distal humerus fractures performed using a posterior paratricipital approach with or without olecranon osteotomy. Main Outcome Measure: Ulnar neuropathy (UN), fracture site bony nonunion, and surgical site infection (SSI). Results: Thirty-one (33.3%) who underwent the paratricipital approach without olecranon osteotomy, and 15 patients (26.8%) who underwent olecranon osteotomy reported postoperative UN with no significant difference between approaches (P = 0.438). There was no significant difference in rates of SSI (P = 0.418) or fracture site nonunion (P = 0.263) when comparing the approaches. Subjects with Charlson comorbidity index ≥2 were more likely to not undergo an olecranon osteotomy (P = 0.01), whereas subjects with more complex fractures by OTA/AO classification were more likely to have an olecranon osteotomy approach (P = 0.001). Conclusions: Addition of an olecranon osteotomy with the paratricipital approach for fixation of distal humerus fractures does not result in higher rates of UN, fracture site nonunion, or SSI. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.