Bone changes after short-term whole body vibration are confined to cancellous bone.

OBJECTIVE: This study assessed femur properties in 80 adult female rats exposed to a range of whole body vibration amplitudes at 45 Hz over five weeks. Our hypothesis was that an optimal amplitude for whole body vibration would be apparent and would result in increased bone strength. METHODS: Animals were treated in five amplitude groups (0 g, 0.15 g, 0.3 g, 0.6 g, and 1.2 g peak), for 15 minutes per day, five days per week, for five weeks. Femur strength was assessed via: (1) three-point bending of the shaft, (2) cantilever bending of the neck, and (3) indentation of distal cancellous bone. Femoral bone mineral density, plasma prostaglandin E2 (PGE2) concentrations, cartilage thickness, and histopathologic properties were measured. RESULTS: Vibration doubled (P=0.039) cancellous bone stiffness in the 0.6 g and 1.2 g groups and induced a 74% increase in PGE2 concentrations (P=0.007). However, femoral densitometry and strength of the neck and shaft were unchanged and the cancellous bone indentation strength did not differ statistically (P=0.084). Cartilage thickness of vibrated groups at the medial condyle did not increase significantly (P=0.142) and the histopathologic grade did not change. There was no definitive optimal vibration amplitude. CONCLUSION: The benefits of vibration therapy over five weeks were confined to cancellous bone.

Prolonged Opioid Use Following Distal Radius Fracture Fixation: Who Is at Risk and What are the Consequences?

Purpose: Opioid pain medication is most commonly prescribed after distal radius fracture fixation, and there is high variability in the quantity and duration prescribed. Comorbidities, including substance use and depression, have been associated with higher consumption habits, and increased sizes of postoperative opioid prescriptions have been previously linked to an increasing risk of chronic opioid use and opioid use disorder. The purpose of this study was to investigate opioid prescription patterns after distal radius fracture fixation and identify patient-specific risk factors associated with increased opioid prescription refills. Methods: A retrospective review of 34,629 opioid-naïve patients was conducted using the IBM MarketScan database. The database was queried to identify patient records from January 2009 to December 2017. Demographic, comorbidity, complication data, and prescription pharmacy claims were analyzed. Patients were sorted according to the duration of postoperative prescription refills of opioid pain medication. Results: Seventy-three percent of the patients required no additional refills outside the perioperative window. Twenty percent required additional refill prescriptions, and 6.4% of patients continued to fill the opioid medication beyond 6 months after surgery. Multiple factors increased the risk of increased opioid use, including medical and surgical complications, substance use, diabetes, cardiovascular disease, and obesity. Patients with a longer duration of opioid use after surgery had higher rates of medical and surgical complications. Perioperative prescription quantities were 62.9, 78.6, and 83.3 tablets for no refill, refill (<6M), and prolonged-use groups (>6M), respectively. Conclusions: Patients who underwent distal radius fracture fixation were at greater odds for prolonged opioid use after surgery in the presence of comorbid cardiovascular, renal, metabolic, and mental health illnesses and postoperative medical and surgical complications. A greater understanding of patient-specific factors for prolonged opioid consumption after distal radius fracture fixation can help providers identify at-risk patients who would benefit from a tailored approach to counseling and multimodal pain management. Patients should be educated on these risks associated with their surgery and be provided with alternative medical options and health care resources to optimize pain control and reduce their need for opioid medication as their primary tool for pain relief. Type of study/level of evidence: Therapeutic III.

Preoperative Depression Is Associated With Increased Complications Following Distal Radius Fracture Surgery.

BACKGROUND: Depression is a known risk factor for inferior outcomes after orthopedic procedures, but its specific relationship with distal radius fractures remains unknown. This study investigates the relationship between preoperative diagnosed depression and common postoperative complications occurring within the first year after open reduction internal fixation (ORIF) for distal radius fractures. METHODS: This retrospective study used Truven MarketScan database and the Current Procedural Terminology (CPT) codes to identify distal radius fracture patients who underwent ORIF in the United States between January 1, 2009, and December 31, 2019. International Classification of Diseases (ICD) codes were used to identify patients with and without a diagnosis of preoperative depression. Univariate, multivariate, t test, and χ2 analyses were performed to determine the association between preoperative depression and postoperative complications following a distal radius fracture surgery. RESULTS: Of the 75 098 eligible patients, 9.9% had at least one ICD code associated with preoperative depression. Preoperative depression was associated with increased odds for surgical site infection (odds ratio [OR] 1.25, confidence interval [CI] 1.14-1.37), emergency department visits for postoperative pain (OR 1.28, CI 1.15-1.36), hardware complication (OR 1.18, CI 1.07-1.30), removal of hardware within 1 year (OR 1.16, CI 1.09-1.27), wound complication (OR 1.17, CI 1.08-1.27), and 30-day readmission (OR 1.21, CI 1.07-1.31). CONCLUSIONS: Preoperative diagnosed depression is associated with increased complications following distal radius fracture surgery. These results can help guide preoperative and postoperative protocols in these higher risk patients. More research is needed to investigate if depression is a modifiable risk factor, as depression treatment could potentially improve postsurgical outcomes.

Predictive Factors Associated with the Need for Simultaneous Carpal Tunnel and Ulnar Nerve at the Elbow Releases.

INTRODUCTION: Carpal tunnel syndrome and ulnar nerve compression at the elbow (e.g., cubital tunnel syndrome) are the most common upper extremity compressive neuropa- thies treated by hand surgeons. The aim of this study was to determine demographic factors and comorbidities that can help predict those patients most likely to undergo concurrent release of both the carpal tunnel and ulnar nerve at the elbow. We hypothesized that certain comorbidities, such as diabetes, would be associated with an increased risk for the necessity of concomitant procedures. METHODS: Using Truven Marketscan® database, all patients who underwent carpal tunnel release were identified from 2010 to 2017 using Current Procedural Terminology (CPT) codes. Patients were only included if they had continuous enrollment in the database for 12 months preoperatively. Preoperative comorbidities and concurrent procedures were collected us- ing CPT and ICD-9 and 10 codes. Patients who underwent simultaneous carpal tunnel and ulnar nerve at the elbow release on the same day were compared to those patients who underwent carpal tunnel release alone. Additionally, patients who underwent either procedure initially and then went on to have the other procedure at a later date were compared. Univariate analysis and binomial logistic regression were performed to assess the contribution of patient demographics and comorbidities on the necessity of simultaneous release. RESULTS: 259,574 patients underwent carpal tunnel release surgery and were included in the study. 24,401 (7.9%) of pa- tients also underwent simultaneous ulnar nerve release at the elbow on the same day. Significant risk factors associated with the need for simultaneous release, were male gender [(Odds Ratio (OR): 2.05, Confidence Interval (CI): 2.00-2.11, p < 0.001)], chronic pain (OR: 1.78, CI: 1.68-1.87, p < 0.001), diabetes (OR: 1.29, CI: 1.25-1.33, p < 0.001), history of al- coholism (OR: 1.23, CI: 1.10-1.38, p < 0.001), chronic renal disease (OR: 1.26, CI: 1.18-1.34, p < 0.001), tobacco use (OR: 1.49, CI: 1.42-1.56, p < 0.001), and patients with congestive heart failure (OR: 1.26, CI: 1.17-1.35, p < 0.001). Patients with consumer driven health plans and high deductible health plans (HDHP) were 1.5 times more likely to have simultane- ous release compared to those with comprehensive plans (OR: 1.46, CI: 1.37-1.56, p < 0.001; OR: 1.45, CI: 1.34-1.57, p < 0.001; respectively). For necessity of subsequent carpal or ulnar nerve release after either primary procedure, patients with a minimum of 3 years enrollment in the database were analyzed. Of the 113,505 patients who underwent initial carpal tunnel release, 1,746 (1.5%) went on to undergo release of the ulnar nerve at the elbow. Of the 12,673 patients who had initial ulnar nerve releases at the elbow, 721 (5.7%) required additional release of the carpal tunnel. CONCLUSION: Identification of patient demographic factors and comorbidities that can help predict the likelihood of si- multaneous release of both the carpal tunnel and ulnar nerve at the elbow can help direct management of these patients. Combining the two procedures can help save resources, minimize patient burden, and help reduce excess health care utilization.

Fractures of the Talus: Current Concepts.

Talus fractures continue to represent a challenging and commonly encountered group of injuries. Its near-complete articular cartilage surface, and its role in force transmission between the leg and foot, makes successful treatment of such injuries a mandatory prerequisite to regained function. Familiarity with the complex bony, vascular, and neurologic anatomy is crucial for understanding diagnostic findings, treatment indications, and surgical techniques to maximize the likelihood of anatomic bony union. This review details the structure and function of the talus, a proper diagnostic workup, the treatment algorithm, and post-treatment course in the management of talus fractures. LEVEL OF EVIDENCE: Level V, expert opinion.

Protein-tyrosine phosphatase (PTP) wedge domain peptides: a novel approach for inhibition of PTP function and augmentation of protein-tyrosine kinase function.

Inhibition of protein-tyrosine phosphatases (PTPs) counterbalancing protein-tyrosine kinases (PTKs) offers a strategy for augmenting PTK actions. Conservation of PTP catalytic sites limits development of specific PTP inhibitors. A number of receptor PTPs, including the leukocyte common antigen-related (LAR) receptor and PTPmu, contain a wedge-shaped helix-loop-helix located near the first catalytic domain. Helix-loop-helix domains in other proteins demonstrate homophilic binding and inhibit function; therefore, we tested the hypothesis that LAR wedge domain peptides would exhibit homophilic binding, bind to LAR, and inhibit LAR function. Fluorescent beads coated with LAR or PTPmu wedge peptides demonstrated PTP-specific homophilic binding, and LAR wedge peptide-coated beads precipitated LAR protein. Administration of LAR wedge Tat peptide to PC12 cells resulted in increased proliferation, decreased cell death, increased neurite outgrowth, and augmented Trk PTK-mediated responses to nerve growth factor (NGF), a phenotype matching that found in PC12 cells with reduced LAR levels. PTPmu wedge Tat peptide had no effect on PC12 cells but blocked the PTPmu-dependent phenotype of neurite outgrowth of retinal ganglion neurons on a PTPmu substrate, whereas LAR wedge peptide had no effect. The survival- and neurite-promoting effect of the LAR wedge peptide was blocked by the Trk inhibitor K252a, and reciprocal co-immunoprecipitation demonstrated LAR/TrkA association. The addition of LAR wedge peptide inhibited LAR co-immunoprecipitation with TrkA, augmented NGF-induced activation of TrkA, ERK, and AKT, and in the absence of exogenous NGF, induced activation of TrkA, ERK, and AKT. PTP wedge domain peptides provide a unique PTP inhibition strategy and offer a novel approach for augmenting PTK function.