Expansion of myeloid-derived suppressor cells contributes to metabolic osteoarthritis through subchondral bone remodeling.

BACKGROUND: Osteoarthritis (OA) subsequent to acute joint injury accounts for a significant proportion of all arthropathies. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of myeloid progenitor cells classically known for potent immune-suppressive activity; however, MDSCs can also differentiate into osteoclasts. In addition, this population is known to be expanded during metabolic disease. The objective of this study was to determine the role of MDSCs in the context of OA pathophysiology. METHODS: In this study, we examined the differentiation and functional capacity of MDSCs to become osteoclasts in vitro and in vivo using mouse models of OA and in MDSC quantitation in humans with OA pathology relative to obesity status. RESULTS: We observed that MDSCs are expanded in mice and humans during obesity. MDSCs were expanded in peripheral blood of OA subjects relative to body mass index and in mice fed a high-fat diet (HFD) compared to mice fed a low-fat diet (LFD). In mice, monocytic MDSC (M-MDSC) was expanded in diet-induced obesity (DIO) with a further expansion after destabilization of the medial meniscus (DMM) surgery to induce post-traumatic OA (PTOA) (compared to sham-operated controls). M-MDSCs from DIO mice had a greater capacity to form osteoclasts in culture with increased subchondral bone osteoclast number. In humans, we observed an expansion of M-MDSCs in peripheral blood and synovial fluid of obese subjects compared to lean subjects with OA. CONCLUSION: These data suggest that MDSCs are reprogrammed in metabolic disease, with the potential to contribute towards OA progression and severity.

Decreased Lean Psoas Cross-Sectional Area Is Associated With Increased 1-Year All-Cause Mortality in Male Elderly Orthopaedic Trauma Patients.

OBJECTIVES: To investigate the association between lean psoas cross-sectional area (CSA) and 1-year all-cause mortality in elderly patients sustaining pelvic and long bone fractures. DESIGN: Retrospective cohort. SETTING: Level I trauma center. PATIENTS: Elderly trauma patients admitted from 2007 to 2014. METHODS: We reviewed demographic and clinical data, injury mechanism, fracture OTA/AO classification, and mortality. Axial computed tomography images were used to measure lean psoas CSA at the L3-L4 disk space. Cox proportional hazard regression analysis was used to estimate 1-year mortality association with psoas CSA in crude and adjusted for age, body mass index, Injury Severity Score, medical comorbidities, and discharge destination in total population and stratified by sex. MAIN OUTCOME MEASUREMENT: One-year all-cause mortality defined as death within 12 months from date of hospitalization. RESULTS: Five hundred fifty-eight patients (54% female, 46% male) were analyzed. The pelvis was most commonly fractured (37.81%). A statistically significant association was observed between decreased lean psoas CSA and 1-year mortality in total population {hazard ratio [HR] = 0.93 [95% confidence interval (CI) = 0.90-0.96], P < 0.0001}. Stratification by gender revealed a statistically significant mortality HR in male patients [HR = 0.89 (95% CI = 0.84-0.96), P = 0.002]. We did not find a statistically significant mortality HR in female patients [HR = 0.95 (95% CI = 0.89-1.01), P = 0.103]. CONCLUSIONS: In this cohort of elderly orthopaedic trauma patients, decreased lean psoas CSA was associated with increased 1-year all-cause mortality in total population and males. Further investigation of the association of sarcopenia with mortality in the elderly is warranted. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Weight bearing cone beam CT scan versus gravity stress radiography for analysis of supination external rotation injuries of the ankle.

For AO 44-B2 ankle fractures of uncertain stability, the current diagnostic standard is to obtain a gravity stress radiograph, but some have advocated for the use of weight-bearing radiographs. The primary aim was to compare measures of medial clear space (MCS) on weight-bearing cone beam computed tomography (CBCT) scans versus gravity stress radiographs for determining the state of stability of ankle fractures classified as AO SER 44-B2 or Weber B. The secondary aim was to evaluate the details offered by CBCT scans with respect to other findings that may be relevant to patient care. Nine patients were enrolled in this cross-sectional study between April 2016 and February 2017 if they had an AO SER 44-B2 fracture of uncertain stability, had a gravity stress radiograph, and were able to undergo CT scan within seven days. The width of the MCS was measured at the level of the talar dome on all radiographs and at the mid coronal slice on CT. Wilcoxon signed-ranks tests were used to compare MCS between initial radiographs, gravity stress radiographs and weight-bearing CBCT scans. MCS on weight-bearing CBCT scan (1.41±0.41 mm) was significantly less than standard radiographs (3.28±1.63 mm, P=0.004) and gravity stress radiographs (5.82±1.93 mm, P=0.02). There was no statistically significant difference in MCS measured on standard radiographs versus gravity stress radiographs (P=0.11). Detailed review of the multiplanar CT images revealed less than perfect anatomical reduction of the fractures, with residual fibular shortening, posterior displacement, and fracture fragments in the incisura as typical findings. Similar to weight-bearing radiographs, weight-bearing CBCT scan can predict stability of AO 44-B2 ankle fractures by showing restoration of the MCS, and might be used to indicate patients for non-operative treatment. None of the fractures imaged in this study were perfectly reduced however, and further clinical research is necessary to determine if any of the detailed weight-bearing CBCT findings are related to patient outcomes.

Tibial Tubercle Fracture After Bone-Patellar Tendon-Bone Autograft.

Fractures occurring with anterior cruciate ligament (ACL) reconstruction are rare and those that do occur take place on the patellar side of a bone-patellar tendon-bone (BPTB) autograft. Here we discuss a far more infrequent occurrence, fracture of the tibial tubercle aspect of the BPTB autograft. This fracture type occurs even more infrequently than tibial plateau fractures after ACL reconstruction based on the published literature. In this article we discuss the third published episode of a tibial tubercle fracture after BPTB allograft. We also discuss the fracture types seen with this method of ACL reconstruction and provide insights into prevention of this occurrence.

Incidence and Injury Types in Motorcycle Collisions Involving Deer in Western New York.

Motorcycle popularity, urban sprawl, and large deer populations result in a significant number of deer-motorcycle collisions. This retrospective review of a level I trauma center in Buffalo, New York, revealed that 40 of 487 (8.2%) of patients admitted because of motorcycle crashes from May 2007 through June 2011 involved deer. There were 120 total injuries: the most common were orthopedic (39/120; 32.5%), chest (38/120; 31.7%), head (18/120; 15.0%), spine (10/120; 8.3%), facial (8/120; 6.7%), and abdominal (7/120; 5.8%). Thirty-five of 40 (87.5%) were men and were older (48.9 years, [SD, 8.9 years]) than the average for all motorcycle crashes during the study period (41.9 years, [SD, 13.9 years]). Mean (SD) injury severity score was 17.1 (9.8), reflecting the severity of encountered injuries. This study highlights the relatively common risk that deer pose to the motorcyclist and is comparable to published series in more rural Midwestern settings.

Donor site morbidity with reamer-irrigator-aspirator (RIA) use for autogenous bone graft harvesting in a single centre 204 case series.

Donor site morbidity and complication rate using the reamer-irrigator-aspirator (RIA) system for intramedullary, non-structural autogenous bone graft harvesting were investigated in a retrospective chart and radiographic review at a University affiliated Level-1 Trauma Centre. 204 RIA procedures in 184 patients were performed between 1/1/2007 and 12/31/2010. RIA-indication was bone graft harvesting in 201 (98.5%), and intramedullary irrigation and debridement in 3 (1.5%) cases. Donor sites were: femur - antegrade 175, retrograde 4, tibia - antegrade 7, retrograde 18. Sixteen patients had undergone two RIA procedures, two had undergone three procedures, all using different donor sites. In 4 cases, same bone harvesting was done twice. Mean volume of bone graft harvested was 47 ± 22ml (20-85 ml). The complication rate was 1.96% (N=4). Operative revisions included 2 retrograde femoral nails for supracondylar femur fractures 6 and 41 days postoperatively (antegrade femoral RIA), 1 trochanteric entry femoral nail (subtrochanteric fracture) 17 days postoperatively (retrograde femoral RIA) and 1 prophylactic stabilization with a trochanteric entry femoral nail for intraoperative posterior femoral cortex penetration without fracture. In our centre, the RIA technique has a low donor site morbidity and has been successfully implemented for harvesting large volumes of nonstructural autogenous bone graft.

Femoral nerve block for diaphyseal and distal femoral fractures in the emergency department. Surgical technique.

BACKGROUND: Diaphyseal and distal femoral fractures are painful injuries that are frequently seen in patients requiring a trauma work-up in the hospital emergency department prior to definitive management. The purpose of this study was to determine whether a femoral nerve block administered in the emergency department could provide better pain relief for patients with femoral fractures than currently used pain management practices. METHODS: Patients who presented with an acute diaphyseal or distal femoral fracture were identified as potential candidates for this study. Eligible patients were randomized by medical record number to receive either (a) the femoral nerve block (20 mL of 0.5% bupivacaine) along with standard pain management or (b) standard pain management alone (typically intravenous narcotics). The pain was assessed with use of a visual analog scale at the initial evaluation and at five, fifteen, thirty, sixty, and ninety minutes following the initial evaluation. Fifty-four patients were enrolled in the study from April 2005 to May 2006. Thirty-one patients received a femoral nerve block, and twenty-three patients received standard pain management alone. RESULTS: Baseline scores on the visual analog pain scale did not differ between the groups at the initial evaluation. The patients who received a femoral nerve block (along with standard pain management) had significantly lower pain scores at five, fifteen, thirty, sixty, and ninety minutes following the block than did the patients who received standard pain management alone (p < 0.001). The score on the visual analog pain scale across these time points was an average of 3.6 points less (on a 10-point scale) for those who received the block. There were no infections, paresthesias, or other complications related to the femoral nerve block. CONCLUSIONS: The acute pain of a diaphyseal or distal femoral fracture can be significantly decreased through the use of a femoral nerve block, which can be administered safely in the hospital emergency department.

F-18 fluoride positron emission tomography of the hip for osteonecrosis.

Osteonecrosis (ON) of the femoral head continues to be a devastating disorder for young patients. We evaluated the F-18 fluoride positron emission tomography (PET) imaging modality for use in detection of the bone involved in ON of the hip. We retrospectively reviewed the records of 60 consecutive patients diagnosed with ON and interviewed all by phone. Eleven patients (17 hips) of those interviewed agreed to participate in the study. We classified the ON using the University of Pennsylvania classification system and compared each patient's plain AP bone scan, single photon emission 3-D computed tomography, and MRI. ON was associated with HIV, alcohol, steroid use, and polycythemia vera in this group. Nine of 17 hips (8 patients) had acetabular increased uptake when using the F-18 fluoride PET scans that were not seen on MRI, single photon emission computed tomography, or bone scans. These data suggest earlier acetabular changes in osteonecrosis may exist that traditional imaging modalities do not reveal.

Femoral nerve block for diaphyseal and distal femoral fractures in the emergency department.

BACKGROUND: Diaphyseal and distal femoral fractures are painful injuries that are frequently seen in patients requiring a trauma work-up in the hospital emergency department prior to definitive management. The purpose of this study was to determine whether a femoral nerve block administered in the emergency department could provide better pain relief for patients with femoral fractures than currently used pain management practices. METHODS: Patients who presented with an acute diaphyseal or distal femoral fracture were identified as potential candidates for this study. Eligible patients were randomized by medical record number to receive either (a) the femoral nerve block (20 mL of 0.5% bupivacaine) along with standard pain management or (b) standard pain management alone (typically intravenous narcotics). The pain was assessed with use of a visual analog scale at the initial evaluation and at five, fifteen, thirty, sixty, and ninety minutes following the initial evaluation. Fifty-four patients were enrolled in the study from April 2005 to May 2006. Thirty-one patients received a femoral nerve block, and twenty-three patients received standard pain management alone. RESULTS: Baseline scores on the visual analog pain scale did not differ between the groups at the initial evaluation. The patients who received a femoral nerve block (along with standard pain management) had significantly lower pain scores at five, fifteen, thirty, sixty, and ninety minutes following the block than did the patients who received standard pain management alone (p < 0.001). The score on the visual analog pain scale across these time-points was an average of 3.6 points less (on a 10-point scale) for those who received the block. There were no infections, paresthesias, or other complications related to the femoral nerve block. CONCLUSIONS: The acute pain of a diaphyseal or distal femoral fracture can be significantly decreased through the use of a femoral nerve block which can be administered safely in the hospital emergency department.