The basilar thumb joint is the joint second most commonly affected by osteoarthritis (OA) in the hand. Evaluation of dorsal subluxation of the thumb during a functional task such as key pinch could help assess OA risk. The objectives of this study were to determine the best imaging angle for measuring thumb dorsal subluxation during key pinch and to compare subluxation to corresponding OA grades on the Eaton-Glickel, Outerbridge, and ICRS scales. Eleven cadavers cadveric forearm specimens were rigged to simulate key pinch. A mobile c-arm captured AP view images of the hand, and rotating in 5° increments toward the ulnar aspect of the arm up to 60°. Dorsal subluxation was measured on each image and compared to determine which angle captured maximum subluxation. The resulting best imaging angle was used for comparisons between dorsal subluxation of the thumb and OA grades for the basilar thumb joint. The max subluxation was in the AP view for most specimens. There was a significant correlation between subluxation and the Eaton-Glickel grade (p=0.003, R2 = 0.779), but not with either Outerbridge grades (p=0.8018) or ICRS grades (p=0.7001). Dorsal Our results indicate that dorsal thumb subluxation during key pinch should be measured in the A-P view of the forearm/handhand view. Dorsal thumb subluxation during key pinch had a significant correlation with the Eaton-Glickel radiographic measure of OA but not with more accurate visual classifications of OA.

Purpose Distal forearm fractures are prevalent among the Medicare population. Many patients who sustain these fractures have poor bone health and are at increased risk for subsequent fractures. We sought to determine the rate of bone mineral density (BMD) testing and subsequent fragility fracture-free interval after distal forearm fractures in the Medicare population. Methods We examined the 5% Medicare Standard Analytic File dataset using the PearlDiver Application from 2005 to 2014 to identify patients with distal forearm fractures based on International Classification of DiseaseseNinth Revision and Current Procedural Terminology codes. We queried these records to determine the incidence and timing of BMD testing after fracture and the number of patients who went on to hip or vertebral fractures. Survival curves were generated using Kaplan-Meier analysis with hip or vertebral fracture as the end point. Results A total of 37,473 patients with distal forearm fractures were identified who did not have BMD testing within the 2 years before fracture. Only 9,605 of this unscreened cohort underwent testing after the fracture (26%) and only 2,684 underwent testing within 6 months (7%). The patients least likely to be tested were males (9%), those aged over 85 years (12%), and those less than 65 years (22%). Twenty percent of these patients sustained a subsequent hip or vertebral fracture (n = 7,326). Patients who underwent testing after fracture had a longer fracture-free interval compared with patients without BMD testing (819 vs 579 days). When separated by sex and controlling for comorbidities, males with BMD testing had a worsened fracture-free interval whereas females had an improved fracture-free interval. Conclusions Bone mineral density testing is underused nationwide in patients sustaining distal forearm fractures despite current guidelines. Orthopedic surgeons should ensure proper testing of patients because this may be an important time point for intervention. Copyright (C) 2021 by the American Society for Surgery of the Hand. All rights reserved.

Laxity of the anterior oblique ligament (AOL) and/or the dorsoradial ligament (DRL) are believed to contribute to the progression of osteoarthritis in the trapeziometacarpal joint through increased dorsal subluxation. Stress radiographs during functional tasks, such as key pinch, can be used to evaluate such joint instability. Cadaveric experiments can explore joint contact pressures as well as subluxation under varying conditions, to gain knowledge about joint mechanics. The disturbance of supporting tissues, such as the joint capsule, during experiments may affect the recorded stability of the joint. To evaluate potential effects of opening the joint capsule and severing the AOL, eleven cadaveric specimens were rigged to simulate key pinch. An anteroposterior (AP) radiograph of the hand was recorded for each specimen while intact, after partially opening the joint capsule and after sectioning the AOL. First metacarpal subluxation levels were compared between the intact joint, partially open joint capsule, and sectioned AOL. Neither opening the joint capsule nor cutting the AOL had a statistically significant effect on metacarpal subluxation. The results indicate that partially opening the joint capsule has a negligible effect on joint mechanics and support recent studies that postulate that the AOL plays a less substantial role in preventing subluxation.

Purpose: We conducted a retrospective study to determine the annual number of patients undergoing various wrist procedures in the Medicare population as well as the revision rate and common revision procedures after carpal instability reconstruction surgeries (Current Procedural Terminology [CPT] billing code 25320). Methods: We examined the Medicare orthopedic datasets using the PearlDiver application to identify patients who underwent 12 different common wrist procedures, including carpal instability reconstruction procedures, from 2005 to 2014. Carpal instability reconstruction procedures were those identified by CPT 25320, which includes various methods of reconstruction such as capsulodesis, ligament repair, and tendon transfer or graft. Medicare covers approximately 51 million Americans and consists of those aged 65 years and older as well as younger patients enrolled in Social Security disability or with end-stage renal disease. Demographic and payment data were determined for the entire cohort. Patients with less than 3 months of active insurance records after the wrist procedure were excluded. Results: A total of 29,898 wrist procedures were performed over the study period. The most commonly performed procedure was wrist arthroscopy with joint debridement or triangular fibrocartilage complex repair (6,557 patients). A total of 2,949 patients underwent carpal instability reconstruction procedures, 174 of whom underwent revision or salvage surgeries (5.9%). The most common revision procedure was an additional reconstruction operation whereas the most common salvage procedure was proximal row carpectomy. Average Medicare payment was $4,107.67 for the index procedure and $3,760.95 for revision procedures. The number of wrist procedures increased 43% over the study period. Conclusions: Carpal instability reconstruction procedures and wrist arthroscopies with joint debridement or TFCC repair are performed more commonly in elderly patients than anticipated or indicated. Procedures such as these, without quality evidence supporting their use in elderly patients, are going to be scrutinized as the United States moves toward value-based health care. Although it appears that carpal reconstruction procedures have a low revision rate in the short to medium term in the Medicare population, the wide variety of procedures captured by CPT 25320 makes outcome measurements challenging. A more specific coding system should be created to reflect the surgeon’s effort more accurately, as well as better track revision rates. Type of study/level of evidence: Therapeutic III. Key words: carpal instability, carpal instability reconstruction, medicare, wrist arthroscopy

Background: We conducted a retrospective study to compare reoperation/conversion rates and costs between open reduction and internal fixation (ORIF) and radial head arthroplasty (RHA) in patients with radial head/neck fractures. Methods: We examined the Humana Orthopedic data sets using the PearlDiver Application from January 2007 to June 2016 to identify patients with radial head and neck fractures with and without a concurrent elbow dislocation. Time to revision surgery, odds ratios, and survival curves for reoperations/conversions were calculated comparing ORIF and RHA. Results: A total of 7520 patients were identified who had undergone either ORIF or RHA. Overall, ORIF patients were less likely to undergo a conversion procedure (2.76% vs 7.03%) but more likely to undergo any reoperation (21.36% vs 17.63%) with a higher average cost ($19 688.46 vs $11 626.64). Patients who underwent ORIF without a concurrent elbow dislocation were also less likely to undergo a conversion procedure (2.12% vs 7.24%) but more likely to undergo any reoperation (20.22% vs 16.99%) with a higher average cost ($19 420.21 vs $11 123.61). Patients who underwent ORIF with a concurrent elbow dislocation were more likely to undergo both a conversion procedure (15.86% vs 6.39%) and any reoperation (44.98% vs 19.63%) with a higher average cost per patient ($24 999.62 vs $13 192.00). The average time to reoperation/conversion surgery was less than a year for all patient groups. Conclusions: Overall reoperation rates are high in patients undergoing operative treatment of radial head and neck fractures. RHA is less expensive and has fewer reoperations/conversions in short-term follow-up when compared with ORIF in radial head/neck fracture dislocations of the elbow.

Introduction Forefoot strike has been advocated for many runners because of the relatively lower impact and push-off forces compared to a heel strike. The purpose of this study was to explore the ability of mature (> 30 years old), experienced runners to transition from a heel foot strike to a forefoot strike when first introduced to barefoot running on a treadmill. We hypothesized: 1) mature runners who heel strike while wearing traditional training shoes would persist in heel striking immediately following a switch to barefoot, 2) mean shoe heel-to-toe drop would be significantly greater in runners who persist in heel striking when running barefoot compared to those who transition to a forefoot strike pattern, and 3) there would be a significant decrease in heel striking in the barefoot condition as running speeds increased. Methods This was a controlled crossover laboratory study. Thirty-three experienced runners (average 23.4 miles per week) with an average age of 45.6 years were recruited for this study. The participants first ran in their standard running shoes and subsequently barefoot. A motion capture system was utilized to detect and analyze any transition from heel strike to forefoot strike made by study participants. Results Of the 26 participants who were classified as heel strike runners in their running shoes, 50% (13/26, p = 0.001) transitioned to forefoot strike when changing from running in shoes to running barefoot. Conclusions The injuries associated with transition from standard running shoes to barefoot running or minimalist shoes may be influenced by the persistence of heel striking in mature runners. Older experienced runners may have limited ability to transition from heel to forefoot striking when first introduced to barefoot running. Mature runners should be cautious when beginning a minimalist shoe or barefoot running regimen.

Purpose: Our objective was to investigate the effects of injury and surgical repair on T2 relaxation time, as a non-invasive biomarker of changes in the biophysical and biochemical status of the cartilage in the wrist. Methods: Magnetic resonance imaging (MRI) was performed using 3T scanners. Nine subjects attended scan sessions for both their injured wrist and contralateral (normal) wrist pre-operation and post-operation. T2 relaxation times were individually calculated by each cartilage surface of the radioscaphoid, radiolunate, capitoscaphoid and capitolunate articulations. Results: T2 relaxation times were not found to vary significantly according to injury state. Overall, findings were not dependent on which cartilage surface was analyzed. Pre-operative and post-operative normal wrist T2 values were not significantly different. Conclusions: Articular cartilage changes due to scapholunate dissociation do not appear to result in changes of T2 relaxation times measured by MRI. The lack of significant findings was possibly a result of thin wrist cartilage and limited image resolution. Further development of MRI capabilities may allow for more accurate determination of the time progression of T2 changes with injury (if any) and/or establish the change in T2 values after surgery.

Background: Scapholunate ligament injury is a commonly occurring carpal ligament injury. Pathology associated with scapholunate ligament injury depends on several factors such as the time after injury, type of injury (instability) and the development of osteoarthritis. The aim of this study was to investigate and compare contact mechanics in the lunocapitate and scaphocapitate joints in the normal, injured (scapholunate dissociation) and repaired (postoperative) wrist.Methods: Four human subjects with scapholunate ligament dissociation participated in this study. MR images of normal (contralateral), injured and postoperative wrists were obtained during relaxed condition and during active light grasp. Relaxed MR images were used to construct model geometry (bones with cartilage) for the capitate, lunate and scaphoid. Kinematic transformations were obtained by using image registration between the unloaded and functionally loaded image sets. Joint surface contact mechanics were then calculated.Findings: All contact measures (contact force, pressure, mean pressure and area) tended to increase with injury in both articulations. A significantly higher contact area was found in the injured scaphocapitate joint compared to normal. A significant increase in peak pressure was observed in the postoperative state compared to normal.Interpretation: Injury to the scapholunate ligament increased contact measures, suggesting a risk for onset of osteoarthritis in both the scaphocapitate and lunocapitate joints. Surgical repair appeared to restore most measures of contact mechanics to near normal values, more so for the lunocapitate joint when compared to scaphocapitate joint. The elevated postoperative peak pressures indicate the diffkulty to fully restore joint mechanics.

This review article summarizes the recent advances in pathogenic mechanisms and novel therapeutic strategies for osteomyelitis, covering both periprosthetic joint infections and fracture-associated bone infections. A better understanding of the pathophysiology including the mechanisms for biofilm formation has led to new therapeutic strategies for this devastating disease. Research on novel local delivery materials with appropriate mechanical properties, lower exothermicity, controlled release of antibiotics, and absorbable scaffolding for bone regeneration is progressing rapidly. Emerging strategies for prevention, early diagnosis of low-grade infections, and innovative treatments of osteomyelitis such as biofilm disruptors and immunotherapy are highlighted in this review.

Objectives: Injuries to the ulnar collateral ligament (UCL) are one of the most common and severe incurred by pitchers. Baseball pitchers of all ages and levels have seen an increase in the diagnosis of these injuries. Tears of the UCL are caused by high valgus forces at the elbow of which the UCL is the primary restraint. Biomechanical studies have demonstrated that baseball pitchers either approach or exceed the maximum tensile strength of the UCL while throwing. Valgus force is additionally resisted by the flexor pronator (FP) muscles: flexor carpi ulnaris (FCU), flexor digitorum superficialis (FDS), and pronator teres (PT), which act as secondary stabilizers. The importance of these secondary stabilizers has not been clearly demonstrated. The goal of this study was to monitor the strength changes in the secondary stabilizers of the elbow over the course of the baseball season and to attempt to correlate any of those changes to observed UCL injuries. Methods: With approval of the Institutional Review Board, 19 professional minor league baseball pitchers were evaluated in spring training and then at the conclusion of the season for flexor-pronator muscle strength. Additionally, their medical histories were assessed for incidents of ulnar collateral ligament injuries and days missed from baseball activities. Each player was assessed using custom testing devices measuring forearm pronation strength, wrist flexion strength, and isolated ring finger FDS strength. Both dominant and non-dominant arms were evaluated and the same testing procedure was performed both at spring training and at the conclusion of the baseball season. Strength was defined as the maximum isometric force generated over three trials. For each test, percentile rank was determined within the sample. A comparison between spring and fall assessments was done using a paired two sample T-test for means. Results: For all three tests, there was a demonstrated decrease of strength in both the pitching arm and non-pitching arm over the season. Pronation strength, wrist flexion strength, and FDS strength to the ring finger decreased 16.1%, 13.7%, and 4.9% respectively in the throwing arm. The decrease in pronation strength and wrist flexion strength in the throwing arm were statistically significant (p=0.001 and 0.003 respectively). Although the non-throwing arm also decreased in strength, it did not reach statistical significance. Two of the nineteen players were diagnosed with ulnar collateral ligament sprains during the season. The two injured players were the 1st and 3rd weakest in a composite percentile strength ranking from the spring assessment. Conclusion: In this study, we showed a diminution of strength of the muscles that act as secondary stabilizers of the ulnar collateral ligament over the course of the professional baseball season. The flexor pronator muscles (specifically the FCU, PT, and FDS) may help protect baseball pitchers from ulnar collateral ligament injuries and weakness of these muscles might make individuals prone to ulnar collateral ligament injuries and subsequent valgus overload syndrome. It is possible that this data would be helpful to predict individuals who are predisposed toward ulnar collateral ligament injuries, as well as in the development of comprehensive flexor-pronator muscle strengthening programs aimed at maintaining secondary stabilizer strength over the course of the baseball season.

Objective: The goal of this study was to demonstrate a methodology to observe the relationship between joint contact pressure and cartilage T2 relaxation times in three-dimensional space. Methods: One subject diagnosed with unilateral scapholunate dissociation had both injured and uninjured wrists scanned using a Siemens 3T Skyra magnetic resonance imaging (MRI) scanner. Four time echo scans were performed with TE ranging 15–61[Formula: see text]ms with the hand relaxed. T2 maps were constructed using a custom Matlab code, and these maps were registered to anatomical images for the same subject. The anatomical images were used to construct surface contact models and calculate contact pressures for a simple grasp activity in a prior study. Contact pressures and T2 relaxation times were analyzed using regression analysis. Results and Conclusion: This study demonstrates the feasibility of comparing T2 relaxation times and contact pressure data. For this single demonstration subject, it is not surprising that no relationship was found between T2 relaxation times for the articular cartilage and contact pressures in the normal wrist, contact pressures in the wrist with injury, nor contact pressure changes due to injury. However, the method has been demonstrated and may be useful to evaluate the influence of joint injuries or other pathologies on T2 relaxation times in the context of changes in joint contact pressures with larger cohorts of subjects.

Objective: The overall goal of this research is to identify completely non-invasive in vivo markers of cartilage degeneration following wrist injury in order to facilitate assessment and treatment of wrist injuries and prevention of osteoarthritis as a result of injury. In this study, the transverse relaxation time, T2, from magnetic resonance imaging (MRI) of the wrist cartilage of subjects exhibiting unilateral scapholunate dissociation was analyzed to evaluate changes in the biochemical status of the cartilage in the wrist following injury. Methods: Data collection consisted of MRI scans of the wrist using 2 separate 3T scanners. Fourteen subjects were analyzed, each subject completed scans to evaluate T2 relaxation times on both their injured and contralateral (normal) wrist. Scans were conducted with a maximum of 0.390625 mm/pixel in-plane pixel size and 1 mm slice thickness. A series of four time echo scans ranging from 15-80 ms were collected. T2 relaxation time for each subject was calculated by registering these echo time scans and fitting the corresponding intensity values to an exponential decay curve. Results: The T2 results from all subjects indicated no statistically significant changes with presence of injury. The use of two separate MRI scanners of the same strength of magnet coil did not cause a significant change in measurement values. Conclusions: Our data suggests that either T2 relaxation time does not change with the presence of scapholunate injury in the wrist or that the change was insufficient to be detected in this study. The results from this study may function as a baseline for future studies examining the potential positive effect surgical repair has on T2 relaxation times.

This study was undertaken to assess magnetic resonance imaging (MRI)-based radiocarpal surface contact models of functional loading in a clinical MRI scanner for future in vivo studies, by comparison with experimental measures from three cadaver forearm specimens. Experimental data were acquired using a Tekscan sensor during simulated light grasp. Magnetic resonance (MR) images were used to obtain model geometry and kinematics (image registration). Peak contact pressures (PPs) and average contact pressures (APs), contact forces and contact areas were determined in the radiolunate and radioscaphoid joints. Contact area was also measured directly from MR images acquired with load and compared with model data. Based on the validation criteria (within 25% of experimental data), out of the six articulations (three specimens with two articulations each), two met the criterion for AP (0%, 14%); one for peak pressure (20%); one for contact force (5%); four for contact area with respect to experiment (8%, 13%, 19% and 23%), and three contact areas met the criterion with respect to direct measurements (14%, 21% and 21%). Absolute differences between model and experimental PPS were reasonably low (within 2.5 MPa). Overall, the results indicate that MRI-based models generated from 3T clinical MR scanner appear sufficient to obtain clinically relevant data.

Study Design: Randomized controlled trial; Level of evidence, 2. Methods: In this 8-week study, 29 runners with a mean age of 36.34 years were randomized into either a control group (n1⁄4 10) who completed training in their regular running shoes or to an experimental barefoot group (n 1⁄4 14). Pretraining tests consisted of a volumetric measurement of the foot followed by a strength and dynamic balance assessment. Five subjects completed the pretests but did not complete the study for reasons not related to study outcomes. Participants then completed 8 weeks of training runs. They repeated the strength and dynamic balance assessment after 8 weeks. Results: Significant changes from baseline to 8 weeks were observed within the barefoot group for single-leg hop (right, P1⁄4 .0121; left, P 1⁄4 .0430) and reach and balance (right, P 1⁄4 .0029) and within the control group for single–left leg hop (P 1⁄4 .0286) and reach and balance (right, P 1⁄4 .0096; left, P 1⁄4 .0014). However, when comparing the differences in changes from baseline to 8 weeks between the barefoot and control groups, the improvements were not significant at the .05 level for all measures.

Purpose To compare the torsional stability of 6 fixation techniques for intercarpal fixation including a 4-tine, in-line staple.Methods We chose the scapholunate interval as the test site for rotational stability for various constructs. We used 42 pairs of embalmed scaphoids and lunates for the comparisons and created 6 construct groups. Fixation of the scapholunate gap was performed with a 3-mm screw, 2 1.1-mm (0.045-inch) K-wires spaced 2 mm apart, or 2 1.1-mm K-wires spaced 5 mm apart. One member of each pair was fixed with either a standard 2-tine peripherally placed staple or a customized 4-tine staple. Each scapholunate construct was tested in torsion to failure on a biaxial materials testing machine.Results In all cases, the 4-tine staple significantly increased rotational stability. The 2-tine staple resulted in statistically insignificant increases in rotational stability. With central fixation alone, K-wires separated by 5 mm showed the greatest resistance to torsion, and the 3-mm screw showed the least.Conclusions Use of an in-line, 4-tine staple provided increased rotational stability and may result in enhanced healing of intercarpal ligamentous reconstructions and arthrodeses. Copyright (C) 2014 by the American Society for Surgery of the Hand. All rights reserved.

BACKGROUND:Hamstring injuries are the second most common injury causing missed days in professional baseball field players. Recent studies have shown the preventive benefit of eccentric conditioning on the hamstring muscle group in injury prevention. Specifically, Nordic-type exercises have been shown to decrease the incidence of acute hamstring injuries in professional athletes. PURPOSE:This was a prospective study performed in coordination with a single Major League Baseball (MLB) organization (major and minor league teams) that targeted the effects of Nordic exercises on the incidence of acute hamstring injuries in the professional-level baseball player. STUDY DESIGN:Prospective cohort study; Level of evidence, 2. METHODS:The daily workouts of 283 professional baseball players throughout all levels of a single MLB organization were prospectively recorded. The intervention group participated in the Nordic exercise program and was compared with a randomly selected control group of professional athletes within the organization not participating in the exercise program. The incidence of hamstring injuries in both groups was compared, and the total number of days missed due to injury was compared with the 2 previous seasons. RESULTS:There were 10 hamstring injuries that occurred during the 2012 season among the 283 professional athletes that required removal from play. There were no injuries that occurred in the intervention group (n = 65, 0.00%; P = .0381). The number needed to treat (NNT) to prevent 1 hamstring injury was 11.3. The average repetitions per week of the injured group were assessed at multiple time points (2, 4, 6, and total weeks) prior to injury. There were significantly fewer repetitions per week performed in the injured group at all time points compared with overall average repetitions per week in the noninjured group (P = .0459, .0127, .0164, and .0299, respectively). After beginning the Nordic exercise program, there were 136 total days missed due to a hamstring injury during the 2012 season. This number was less than the 2011 season (273 days missed) and the 2010 season (309 days missed). CONCLUSION:Study results indicate the initiation of Nordic hamstring exercises may decrease the incidence of acute hamstring injuries and potentially decrease the total number of days missed due to injury in professional baseball players. CLINICAL RELEVANCE:The financial and competitive interest in professional baseball players is of large importance to the player, team, and fans. Prevention of injuries is as important to all parties involved as the treatment and rehabilitation following an injury. This prospective study shows the initiation of a simple, free exercise can reduce the incidence of hamstring injury in the professional-level baseball player.

Background: It has been proposed that running barefoot can lead to improved strength and proprioception. However, the duration that a runner must train barefoot to observe these changes is unknown. Hypothesis: Runners participating in a barefoot running program will have improved proprioception, increased lower extremity strength, and an increase in the volume or size of the intrinsic musculature of the feet. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: In this 8-week study, 29 runners with a mean age of 36.34 years were randomized into either a control group (n = 10) who completed training in their regular running shoes or to an experimental barefoot group (n = 14). Pretraining tests consisted of a volumetric measurement of the foot followed by a strength and dynamic balance assessment. Five subjects completed the pretests but did not complete the study for reasons not related to study outcomes. Participants then completed 8 weeks of training runs. They repeated the strength and dynamic balance assessment after 8 weeks. Results: Significant changes from baseline to 8 weeks were observed within the barefoot group for single-leg hop (right, P = .0121; left, P = .0430) and reach and balance (right, P = .0029) and within the control group for single–left leg hop ( P = .0286) and reach and balance (right, P = .0096; left, P = .0014). However, when comparing the differences in changes from baseline to 8 weeks between the barefoot and control groups, the improvements were not significant at the .05 level for all measures. Conclusion: Although statistically significant changes were not observed between the pre- and posttest evaluations in strength and proprioception with the 8-week low-intensity barefoot running regimen, this does not necessarily mean that these changes do not occur. It is possible that it may take months or years to observe these changes, and a short course such as this trial is insufficient.