Incidence of Carpal Tunnel Syndrome after Distal Radius Fracture.

Purpose: Carpal tunnel syndrome (CTS) can present following distal radius fracture (DRF) and may progress to require carpal tunnel release (CTR). The primary aim of this study was to determine the incidence of CTS within 6 months of a DRF and the rate of CTR in this population. Methods: We used the PearlDiver national insurance database to determine the incidence of CTS after DRF. Patients were identified by International Classification of Diseases-10 codes, and treatment modalities for DRF and CTS were determined by respective Current Procedural Terminology codes. Patients with less than 6 months of follow-up, bilateral DRF, or preexisting CTS were excluded. Patient demographic characteristics were recorded. The time from DRF diagnosis to CTS diagnosis and CTR was determined. A multivariable analysis was performed to determine the differences between patients who underwent a CTR compared with those who were treated conservatively. Results: We identified 23,733 patients (6,015 men; 17,718 women) who sustained a DRF. Of these patients, 79.1% were treated nonsurgically and 20.9% underwent surgical fixation. In total, 9.2% (N = 2,179) were diagnosed with CTS in their ipsilateral extremity within 6 months of sustaining the DRF. Of the patients whose DRF was treated nonsurgically, 6.3% (N = 1,198) developed CTS and 2.9% (N = 546) required CTR. Of those patients whose DRF was treated surgically, 19.8% (N = 981) developed CTS and 13.3% (N = 661) required CTR. Of those patients with symptoms severe enough to warrant CTR, 18.5% required a second surgical intervention for the CTR. Conclusions: Distal radius fractures severe enough to require surgical fixation are associated with a higher incidence of perioperative CTS. Accordingly, careful evaluation for and counseling on CTS during surgical fixation may decrease the chance of a second surgery. We have identified a cohort of patients with DRFs who may benefit from prophylactic CTR. Type of study/level of evidence: Diagnostic IV.

Open Ankle Fractures: What Predicts Infection? A Multicenter Study.

OBJECTIVE: To identify the patient, injury, and treatment factors associated with an acute infection during the treatment of open ankle fractures in a large multicenter retrospective review. To evaluate the effect of infectious complications on the rates of nonunion, malunion, and loss of reduction. DESIGN: Multicenter retrospective review. SETTING: Sixteen trauma centers. PATIENTS: One thousand and 3 consecutive skeletally mature patients (514 men and 489 women) with open ankle fractures. MAIN OUTCOME MEASURES: Fracture-related infection (FRI) in open ankle fractures. RESULTS: The charts of 1003 consecutive patients were reviewed, and 712 patients (357 women and 355 men) had at least 12 weeks of clinical follow-up. Their average age was 50 years (range 16-96), and average BMI was 31; they sustained OTA/AO types 44A (12%), 44B (58%), and 44C (30%) open ankle fractures. The rate FRI rate was 15%. A multivariable regression analysis identified male sex, diabetes, smoking, immunosuppressant use, time to wound closure, and wound location as independent risk factors for infection. There were 77 cases of malunion, nonunion, loss of reduction, and/or implant failure; FRI was associated with higher rates of these complications (P = 0.01). CONCLUSIONS: Several patient, injury, and surgical factors were associated with FRI in the treatment of open ankle fractures. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Are Continuous Femoral Nerve Catheters Beneficial for Pain Management After Operative Fixation of Tibial Plateau Fractures? A Randomized Controlled Trial.

OBJECTIVE: To determine whether a continuous femoral nerve block after open reduction internal fixation of tibial plateau fractures would diminish Visual Analog Scale (VAS) scores and/or systemic narcotic intake. DESIGN: Randomized controlled trial. SETTING: Level 1 academic trauma center. PATIENTS: Forty-two consecutive patients with operatively treated tibial plateau fractures. INTERVENTION: Continuous femoral nerve catheter for postoperative pain management was performed in the experimental group. MAIN OUTCOME MEASURES: Both the VAS scores for pain and narcotic intake were assessed at 4, 8, 12, 24, 36, 48, and 72 hours postoperatively. RESULTS: Forty-two patients were enrolled in this study. There were 21 women and 21 men 21-70 years of age (avg 49) with operatively treated tibial plateau fractures. Twenty-one patients were randomized to receive a femoral nerve block with 5 crossovers for technical reasons. Accordingly, we analyzed 16 patients with femoral nerve blocks and 26 with standard care. There were no significant differences between the study groups regarding age, sex, or fracture type. There was no significant difference in VAS scores between the control and experimental group at any time point. The total systemic morphine equivalent for the femoral nerve block group and the control group was 375 and 397 respectively (P = 0.76). Across groups, patients with bicondylar fractures tended to have higher VAS than those with unicondylar fractures and to use more narcotics, although neither was statistically significant. CONCLUSION: Femoral nerve blocks for postoperative pain management in tibial plateau fractures did not demonstrate an improvement in pain relief or narcotic use. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Correlation between RUST assessments of fracture healing to structural and biomechanical properties.

Radiographic Union Score for Tibia (RUST) and modified RUST (mRUST) are radiographic tools for quantitatively evaluating fracture healing using a cortical scoring system. This tool has high intra-class correlation coefficients (ICCs); however, little evidence has evaluated the scores against the physical properties of bone healing. Closed, stabilized fractures were made in the femora of C3H/HeJ male mice (8-12 week-old) of two dietary groups: A control and a phosphate restricted diet group. Micro-computed tomography (µCT) and torsion testing were carried out at post-operative days (POD) 14, 21, 35, and 42 (n = 10-16) per group time-point. Anteroposterior and lateral radiographic views were constructed from the µCT scans and scored by five raters. The raters also indicated if the fracture were healed. ICCs were 0.71 (mRUST) and 0.63 (RUST). Both RUST scores were positively correlated with callus bone mineral density (BMD) (r = 0.85 and 0.80, p < 0.001) and bone volume fraction (BV/TV) (r = 0.86 and 0.80, p < 0.001). Both RUST scores positively correlated with callus strength (r = 0.35 and 0.26, p < 0.012) and rigidity (r = 0.50 and 0.39, p < 0.001). Radiographically healed calluses had a mRUST ≥13 and a RUST ≥10 and had excellent relationship to structural and biomechanical metrics. Effect of delayed healing due to phosphate dietary restrictions was found at later time points with all mechanical properties (p < 0.011), however no differences found in the RUST scores (p > 0.318). Clinical relevance of this study is both RUST scores showed high correlation to physical properties of healing and generally distinguished healed vs. non-healed fractures. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:945-953, 2018.

Serum proteomic assessment of the progression of fracture healing.

A targeted proteomic analysis of murine serum over a 35-day course of fracture healing was carried out to determine if serum proteomic changes could be used to monitor the biological progression of fracture healing. Transverse, closed femoral fractures where generated and stabilized with intramedullary fixation. A single stranded DNA aptamer-based multiplexed proteomic approach was used to assay 1,310 proteins. The transcriptomic profiles for genes matching the 1,310 proteins were obtained by microarray analysis of callus mRNA. Of the 1,310 proteins analyzed, 850 proteins showed significant differences among the time points (p-value <0.05). Ontology assessment associated these proteins with osteoblasts, monocyte/macrophage lineages, mesenchymal stem cell lines, hepatic tissues, and lymphocytes. Temporal clustering of these data identified proteins associated with inflammation, cartilage formation and bone remodeling stages of healing. VEGF, Wnt, and TGF-ßsignaling pathways were restricted to the period of cartilage formation. Comparison of the proteomic and transcriptomic profiles showed that 87.5% of proteins in serum had concordant expression to their mRNA expression in the callus, while 12.5% of the protein and mRNA expression patterns were discordant. The discordant proteins that were elevated in the serum but down regulated in callus mRNA expression were related to clotting functions, allograft rejection, and complement function. While proteins down regulated in the serum and elevated in callus mRNA were associated with osteoblast function, NF-ĸb, and activin signaling. These data show the serum proteome may be used to monitor the different biological stages of fracture healing and have translational potential in assessing human fracture healing. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1153-1163, 2018.

ECM stiffness primes the TGFß pathway to promote chondrocyte differentiation.

Cells encounter physical cues such as extracellular matrix (ECM) stiffness in a microenvironment replete with biochemical cues. However, the mechanisms by which cells integrate physical and biochemical cues to guide cellular decision making are not well defined. Here we investigate mechanisms by which chondrocytes generate an integrated response to ECM stiffness and transforming growth factor ß (TGFß), a potent agonist of chondrocyte differentiation. Primary murine chondrocytes and ATDC5 cells grown on 0.5-MPa substrates deposit more proteoglycan and express more Sox9, Col2α1, and aggrecan mRNA relative to cells exposed to substrates of any other stiffness. The chondroinductive effect of this discrete stiffness, which falls within the range reported for articular cartilage, requires the stiffness-sensitive induction of TGFß1. Smad3 phosphorylation, nuclear localization, and transcriptional activity are specifically increased in cells grown on 0.5-MPa substrates. ECM stiffness also primes cells for a synergistic response, such that the combination of ECM stiffness and exogenous TGFß induces chondrocyte gene expression more robustly than either cue alone through a p38 mitogen-activated protein kinase-dependent mechanism. In this way, the ECM stiffness primes the TGFß pathway to efficiently promote chondrocyte differentiation. This work reveals novel mechanisms by which cells integrate physical and biochemical cues to exert a coordinated response to their unique cellular microenvironment.

Peripheral blood leukocyte counts in cytomegalovirus infected heart transplant patients: impact of acute disease versus subclinical infection.

BACKGROUND: Cytomegalovirus (CMV)-associated leucopenia in heart transplant patients is poorly characterized. METHODS: We conducted a retrospective analysis of timing, degree, and type of leukopenia in four groups of patients: cases (n=20); controls (n=20); subclinical early infection (n=21), and subclinical late infection (n=22). In the cases, white blood cells (WBC) count at diagnosis was compared to prediagnosis; and cases were compared to controls. Subclinical cases (early and late) were identified by measurement of CMV DNA in peripheral blood mononucleocytes, and WBC was compared to those of the cases and controls. RESULTS: First, in human heart transplant recipients the total leukocyte count decreased prior to the time of diagnosis of CMV disease: cases: 5.4+/-2.1 x 10/microL vs. 3.7+/-2.1x10/muL (P<0.01); subclinical early: 8.1+/-4.1 x 10/microL vs. 6.9+/-1.6 x 10/microL (P<0.01). Second, the leukocyte populations most reduced during CMV disease are the neutrophils: 4.4 x 10/microL (78%) to 2.5 x 10/microL (69%) (P<0.05), and monocytes 0.6 x 10/microL (11%) to 0.3 x 10/microL (7.5%) (P<0.05). Third, the reduction in leukocyte count that occurs during CMV disease appears to be independent of immunosuppressive therapy (using cyclosporine A, mycophenolate mofetil, or azathioprine and prednisone). Finally, subclinical CMV infection in stable long-term heart transplant patients without disease is unassociated with a reduction in the leukocyte count. CONCLUSIONS: Aside from implications for early diagnosis, CMV-associated decrease in monocytes is important because viral infections like Epstein-Barr virus cause monocytosis. The absence of leucopenia in subclinical late infections is a new important finding.