Knowledge of radiation exposure associated with common trauma imaging modalities among orthopaedic surgeons, emergency medicine physicians, and general surgeons in the United States.

BACKGROUND: Few contemporary studies have assessed physicians' knowledge of radiation exposure associated with common imaging studies, especially in trauma care. The purpose of this study was to assess the knowledge of physicians involved in caring for trauma patients regarding the effective radiation doses of musculoskeletal (MSK) imaging studies routinely utilized in the trauma setting. METHODS: An electronic survey was distributed to United States orthopaedic surgery, general surgery, and emergency medicine (EM) residency programs. Participants were asked to estimate the radiation dose for common imaging modalities of the pelvis, lumbar spine, and lower extremity, in terms of chest X-ray (CXR) equivalents. Physician estimates were compared to the true effective radiation doses. Additionally, participants were asked to report the frequency of discussing radiation risk with patients. RESULTS: A total of 218 physicians completed the survey; 102 (46.8%) were EM physicians, 88 (40.4%) were orthopaedic surgeons, and 28 (12.8%) were general surgeons. Physicians underestimated the effective radiation doses of nearly all imaging modalities, most notably for pelvic computed tomaography (CT) (median 50 CXR estimation vs. 162 CXR actual) and lumbar CT (median 50 CXR estimation vs. 638 CXR actual). There was no difference between physician specialties regarding estimation accuracy (P=0.133). Physicians who regularly discussed radiation risks with patients more accurately estimated radiation exposure (P=0.007). CONCLUSION: The knowledge among orthopaedic and general surgeons and EM physicians regarding the radiation exposure associated with common MSK trauma imaging is lacking. Further investigation with larger scale studies is warranted, and additional education in this area may improve care.

Use of single agent Cefotetan for Gustilo-Anderson type III open fracture prophylaxis.

INTRODUCTION: The prophylactic intravenous antibiotic regimen for Gustilo-Anderson Type III open fractures traditionally consists of cefazolin with an aminoglycoside plus penicillin for gross contamination. Cefotetan, a second-generation cephalosporin, offers a wide spectrum of activity against both aerobes and anaerobes as well as against Gram-positive and Gram-negative bacteria. Cefotetan has not been previously established within orthopedic surgery as a prophylactic intravenous agent. PATIENTS AND METHODS: Cefotetan monotherapeutic prophylaxis versus any other antibiotic regimen (standard/literature-supported and otherwise) was studied for patient encounters between September 2010 and December 2019 within a single Level 1 regional trauma center. Patient comorbidities, preoperative fracture characteristics, and in-hospital/operative metrics (including length of stay [LOS], number of antibiotic doses, and antibiotic costs [US$]) were included for analysis. Postoperative outcomes up to 1 year included rates of surgical site infection (SSI), deep infection necessitating return to the operating room (OR), non-union, prescribed outpatient antibiotics, hospital readmissions, and related returns to the emergency department (ED). Sensitivity analyses were also conducted to include standard/literature-supported antibiotic regimens as a nested random factor within the non-cefotetan cohort. RESULTS: The nested variable accounting for standard/literature-supported antibiotic regimens had no significant effect in any model for any outcome (for each, P ≥ 0.302). Thus, 1-year data for 138 Type III open fractures were included, accounting for only the binary effect of cefotetan (n = 42) versus non-cefotetan cohorts. The cohorts did not differ significantly at baseline. The cefotetan cohort received fewer in-house dose/day antibiotics (P < 0.001), was less likely to receive outpatient antibiotics in the following year (P = 0.023), had decreased return to the OR (35.7% versus 54.2%, P = 0.045), and demonstrated non-union rates of 16.7% versus 28.1% (P = 0.151). When adjusted for length of stay (LOS), the dose/day total costs for antibiotics were $8.71/day more expensive for the cefotetan cohort (P = 0.002). Type III open fractures incurred overall rates of SSI reaching 16.7% in the cefotetan cohort and 14.7% for non-cefotetan (P = 0.773). Deep infections necessitating return to the OR were 9.5% and 11.6%, respectively (P = 0.719). CONCLUSION: Cefotetan alone may provide superior antibiotic stewardship with similar infectious sequalae compared to more traditional antibiotic prophylaxis regimens for Gustilo-Anderson Type III open long bone fractures. LEVEL OF EVIDENCE: Level III Retrospective Cohort Study.

Reduction in Operating Room Airborne Particle Burden and Time-Dependent Contamination of Sterile Instrument Trays With the Use of a Novel Air Filtration System.

Introduction Postoperative infections represent a substantial burden to patients and healthcare systems. To improve patient care and reduce healthcare expenditures, interventions to reduce surgical infections must be employed. The crystalline C-band ultraviolet (UV-C) air filtration technology (Aerobiotix Inc., Miamisburg, OH, USA) has been designed to reduce airborne bioburden through high-quality filtration and germicidal irradiation. The purpose of this study was to assess the ability of a novel UV-C air filtration device to reduce airborne particle counts and contamination of surgical instrument trays in an operating room (OR) setting. Materials and methods Thirty sterile instrument trays were opened in a positive-air-flow OR. The trays were randomly assigned to one of two groups (UV-C or control, n=15 per group). In the UV-C group, the UV-C filtration device was used and in the control, it was not. All trays were opened with the use of a sterile technique and left exposed in the OR for four hours. Air was sampled by a particle counter to measure the numbers of 5µm and 10µm particles. Culture specimens were obtained from the trays to assess for bacterial contamination. Outcome data were collected at 30-minute intervals for the duration of the four-hour study period. Results Use of the UV-C device resulted in statistically significant reductions in the numbers of 5µm (average of 64.9% reduction when compared with the control, p<0.001) and 10µm (average of 65.7% reduction when compared with the control, p<0.001)-sized particles detectable in the OR. There was no significant difference in the overall rates of contamination (33.3% in the control group vs. 26.7% in the UV-C group, p=1.0) or the time to contamination (mean survival of 114 minutes in the control group vs. 105 minutes in the UV-C group, p=0.72) of surgical instrument trays with the use of the UV-C device. Conclusions The results demonstrate that the UV-C filtration device can successfully reduce airborne bioburden in standard ORs, suggesting that it may have the potential to reduce the risk for wound and hardware infections. Further clinical trials are necessary to better determine the effect of this air filtration system on postoperative infection rates.

Cyclic Damage Accumulation in the Femoral Constructs Made With Cephalomedullary Nails.

Background: The purpose of this study was to evaluate the risk of peri-prosthetic fracture of constructs made with cephalomedullary (CM) long and short nails. The nails were made with titanium alloy (Ti-6Al-4V) and stainless steel (SS 316L). Methods: Biomechanical evaluation of CM nail constructs was carried out with regard to post-primary healing to determine the risk of peri-implant/peri-prosthetic fractures. Therefore, this research comprised of, non-fractured, twenty-eight pairs of cadaveric femora that were randomized and implanted with four types of fixation CM nails resulting in four groups. These constructs were cyclically tested in bi-axial mode for up to 30,000 cycles. All the samples were then loaded to failure to measure failure loads. Three frameworks were carried out through this investigation, Michaelis-Menten, phenomenological, and probabilistic Monte Carlo simulation to model and predict damage accumulation. Findings: Damage accumulation resulting from bi-axial cyclic loading in terms of construct stiffness was represented by Michaelis-Menten equation, and the statistical analysis demonstrated that one model can explain the damage accumulation during cyclic load for all four groups of constructs (P > 0.05). A two-stage stiffness drop was observed. The short stainless steel had a significantly higher average damage (0.94) than the short titanium nails (0.90, P < 0.05). Long titanium nail group did not differ substantially from the short stainless steel nails (P > 0.05). Results showed gender had a significant effect on load to failure in both torsional and bending tests (P < 0.05 and P < 0.001, respectively). Interpretation: Kaplan-Meier survival analysis supports the use of short titanium CM nail. We recommend that clinical decisions should take age and gender into consideration in the selection of implants.

The Role of Far Cortical Endosteal Fixation for the Treatment of Medial Malleolus Fractures: A Biomechanical Study.

The traditional method for fixation of medial malleolus fractures has been with partially threaded (PT) lag screws extending beyond the physeal scar. The purpose of this study was to evaluate the biomechanical strength of an innovative method of fixation for medial malleolus fractures using a fully threaded (FT) lag screw that extends to the far endosteal cortex. Medial malleolus fractures were simulated in 12 matched cadaver pairs. A single PT 4.0-mm cancellous lag screw was placed in 1 ankle. The contralateral ankle of the same matched pair received an FT 3.5-mm cortical lag screw that extended to the far lateral tibial cortex and achieved endosteal purchase. Final torque of both screw configurations was recorded, and radiographs were taken to confirm appropriate screw placement. Average torque for the PT cancellous screws was 5.02 ± 2.34 in-lb. Average torque for the FT cortical screw was 7.63 ± 3.86 in-lb (p = .002). Visual and radiographic inspections revealed no displacement of the fracture site with use of the FT endosteal lag screw. Our results indicate superior biomechanical torque with far endosteal fixation with use of an FT cortical lag screw versus a traditional PT cancellous lag screw in a cadaver model. Far endosteal fixation is an alternative surgical option for medial malleolus fractures that provides added strength compared with PT lag screws and may obviate downsides associated with bicortical fixation.

A biomechanical cadaver comparison of suture button fixation to plate fixation for pubic symphysis diastasis.

OBJECTIVES: To determine whether suture button fixation of the pubic symphysis is biomechanically similar to plate fixation in the treatment of partially stable pelvic ring injuries. METHODS: Twelve pelvis specimens were harvested from fresh frozen cadavers. Dual-x-ray-absorptiometry (DXA) scans were obtained for all specimens. The pubic symphysis of each specimen was sectioned to simulate a partially stable pelvic ring injury. Six of the pelvises were instrumented using a 6 hole, 3.5 mm low profile pelvis plate and six of the pelvises were instrumented with two suture button devices. Biomechanical testing was performed on a pneumatic testing apparatus in a manner that simulates vertical stance. Displacement measurements of the superior, middle, and inferior pubic symphysis were obtained prior to loading, after an initial 440 N load, and after 30,000 and 60,000 rounds of cyclic loading. Statistical analysis was performed using Wilcoxon-Mann-Whitney tests, Fisher's exact test, and Cohen's d to calculate effect size. Significance was set at p < 0.05. RESULTS: There was no difference between groups for DXA T scores (p = 0.749). Between group differences in clinical load to failure (p = 0.65) and ultimate load to failure (p = 0.52) were not statistically significant. For symphysis displacement, the change in fixation strength and displacement with progressive cyclic loading was not significant when comparing fixation types (superior: p = 0.174; middle: p = 0.382; inferior: p = 0.120). CONCLUSION: Suture button fixation of the pubic symphysis is biomechanically similar to plate fixation in the management of partially stable pelvic ring injuries.

Gun barrel view of the anterior pelvic ring for percutaneous anterior column or superior pubic ramus screw placement.

BACKGROUND: Traditionally, operative fixation of pelvic and acetabular injuries involves complex approaches and significant complications. Accelerated rehabilitation, decreased soft tissue stripping and decreased wound complications are several benefits driving a recent interest in percutaneous fixation. We describe a new fluoroscopic view to guide the placement of screws within the anterior pelvic ring. METHODS: Twenty retrograde anterior pelvic ring screws were percutaneously placed in ten cadaveric specimens. Arranging a standard C-arm in a position similar to obtaining a lateral hip image, with angles of 54° ± 2° beam to body, 75° ± 5° of reverse cantilever and 14° ± 6° of outlet, a gun barrel view of the anterior pelvic ring is identified. Fluoroscopic images were taken, and the hemipelvi were harvested to examine the dimensions of the anterior pelvic ring and inspected for any cortical or articular perforation. RESULTS: The minimum cranial-to-caudal distance in the anterior pelvic ring was 9 mm (range 6.5-12 mm), and the minimum anterior-to-posterior dimension was 9 mm (range 5-15 mm). All but 2 screws were completely confined within the osseous corridors. Identifiable on final fluoroscopic evaluation, one screw perforated the psoas groove and a second perforated the acetabular dome. Overall, 90 % of our screws were accurately and safely placed, upon the first attempt, within the anterior pelvic ring using the described gun barrel view. CONCLUSION: Employing either open reduction, or following a closed or percutaneous reduction, the anterior pelvic ring gun barrel view can reproducibly guide safe placement of anterior pelvic ring screw fixation. LEVEL OF EVIDENCE: IV.

Epidemiology of Fracture Nonunion in 18 Human Bones.

Importance: Failure of bone fracture healing occurs in 5% to 10% of all patients. Nonunion risk is associated with the severity of injury and with the surgical treatment technique, yet progression to nonunion is not fully explained by these risk factors. Objective: To test a hypothesis that fracture characteristics and patient-related risk factors assessable by the clinician at patient presentation can indicate the probability of fracture nonunion. Design, Setting, and Participants: An inception cohort study in a large payer database of patients with fracture in the United States was conducted using patient-level health claims for medical and drug expenses compiled for approximately 90.1 million patients in calendar year 2011. The final database collated demographic descriptors, treatment procedures as per Current Procedural Terminology codes; comorbidities as per International Classification of Diseases, Ninth Revision codes; and drug prescriptions as per National Drug Code Directory codes. Logistic regression was used to calculate odds ratios (ORs) for variables associated with nonunion. Data analysis was performed from January 1, 2011, to December 31, 2012. Exposures: Continuous enrollment in the database was required for 12 months after fracture to allow sufficient time to capture a nonunion diagnosis. Results: The final analysis of 309 330 fractures in 18 bones included 178 952 women (57.9%); mean (SD) age was 44.48 (13.68) years. The nonunion rate was 4.9%. Elevated nonunion risk was associated with severe fracture (eg, open fracture, multiple fractures), high body mass index, smoking, and alcoholism. Women experienced more fractures, but men were more prone to nonunion. The nonunion rate also varied with fracture location: scaphoid, tibia plus fibula, and femur were most likely to be nonunion. The ORs for nonunion fractures were significantly increased for risk factors, including number of fractures (OR, 2.65; 95% CI, 2.34-2.99), use of nonsteroidal anti-inflammatory drugs plus opioids (OR, 1.84; 95% CI, 1.73-1.95), operative treatment (OR, 1.78; 95% CI, 1.69-1.86), open fracture (OR, 1.66; 95% CI, 1.55-1.77), anticoagulant use (OR, 1.58; 95% CI, 1.51-1.66), osteoarthritis with rheumatoid arthritis (OR, 1.58; 95% CI, 1.38-1.82), anticonvulsant use with benzodiazepines (OR, 1.49; 95% CI, 1.36-1.62), opioid use (OR, 1.43; 95% CI, 1.34-1.52), diabetes (OR, 1.40; 95% CI, 1.21-1.61), high-energy injury (OR, 1.38; 95% CI, 1.27-1.49), anticonvulsant use (OR, 1.37; 95% CI, 1.31-1.43), osteoporosis (OR, 1.24; 95% CI, 1.14-1.34), male gender (OR, 1.21; 95% CI, 1.16-1.25), insulin use (OR, 1.21; 95% CI, 1.10-1.31), smoking (OR, 1.20; 95% CI, 1.14-1.26), benzodiazepine use (OR, 1.20; 95% CI, 1.10-1.31), obesity (OR, 1.19; 95% CI, 1.12-1.25), antibiotic use (OR, 1.17; 95% CI, 1.13-1.21), osteoporosis medication use (OR, 1.17; 95% CI, 1.08-1.26), vitamin D deficiency (OR, 1.14; 95% CI, 1.05-1.22), diuretic use (OR, 1.13; 95% CI, 1.07-1.18), and renal insufficiency (OR, 1.11; 95% CI, 1.04-1.17) (multivariate P < .001 for all). Conclusions and Relevance: The probability of fracture nonunion can be based on patient-specific risk factors at presentation. Risk of nonunion is a function of fracture severity, fracture location, disease comorbidity, and medication use.

Timing of C-arm drape contamination.

BACKGROUND: Surgical site infection remains a concern in orthopedic surgery, and contamination of C-arm covers is a potentially modifiable risk factor. METHODS: A single-cohort study was conducted using 30 consecutive patients undergoing operative fracture fixation. Cultures were obtained from the C-arm cover after initial draping and every 20 min thereafter. The total number of persons in the operating room (person-hours/h of study time) and the number of door openings were recorded. The C-arm position changes and the time to contamination were monitored. RESULTS: The median time from the start of the operation to contamination was 20 min. There was a 17% contamination rate on initial draping, 50% at 20 min, 57% at 40 min, and 80% by 80 min. The C-arms in five cases were not contaminated during the surgery. Time to contamination correlated significantly with lateral position changes (correlation [r]=0.64; p=0.003) but was not related to C-arm position changes (r=0.22; p=0.34), number of door openings (r=0.20; p=0.39), or person-hours/h (r=0.04; p=0.85). CONCLUSIONS: Contamination of the C-arm drape occurs often and early during surgery for orthopedic fractures. We recommend minimal contact with the C-arm to avoid contamination of the surgical field.

The protective effect of locking screw placement on nonlocking screw extraction torque in an osteoporotic supracondylar femur fracture model.

OBJECTIVE: To examine the impact of number and position of locking screws in the diaphyseal portion of an osteoporotic distal femoral fracture model with hybrid fixation. METHODS: Four groups containing 5 osteoporotic bone models were used with varying combinations of diaphyseal screw fixation: 4 nonlocking screws (control); 1 locking screw adjacent to the osteotomy and 3 nonlocking screws; 1 locking screw in the most proximal screw hole of the plate and 3 nonlocking screws; and 2 locking screws at opposite ends of the diaphyseal fixation with 2 nonlocking screws in between. Fixation in the distal articular segment was identical in all constructs. Testing was performed for 50,000 cycles at 2 Hz using simultaneous axial compression (700 N) and bidirectional torque (±5 Nm) applied along the long axis of the bone. All screws were inserted with 4 Nm of torque. RESULTS: The extraction torque for nonlocking screws in those specimens that had a locking screw nearest the osteotomy was significantly greater than those that did not (P = 0.037). In addition, the 10 constructs with a locking screw nearest the osteotomy had no failures compared with 5 of 10 failures in those without a locking screw in this position (P = 0.033). CONCLUSIONS: The placement of a locking screw adjacent to the osteotomy was more beneficial in protecting against failure and maintaining the extraction torque of neighboring proximal nonlocking screws. No benefit in adjacent screw extraction torque was seen with a locking screw proximal in the diaphysis. Two locking screws at opposite ends of the diaphyseal fixation were not superior to a single locking screw adjacent to the osteotomy in failure rates or screw extraction torque.

Repeated freeze-thaw cycles do not alter the biomechanical properties of fibular allograft bone.

BACKGROUND: Allograft tissues can undergo several freeze-thaw cycles between donor tissue recovery and final use by surgeons. However, there are currently no standards indicating the number of reasonable freeze-thaw cycles for allograft bone and it is unclear how much a graft may be degraded with multiple cycles. QUESTIONS/PURPOSES: We therefore asked whether (1) the mechanical properties of fibular allograft bone would remain unchanged with increasing numbers of freeze-thaw cycles and (2) histologic alterations from increased numbers of freeze-thaw cycles would correspond to any mechanical changes. METHODS: Fibular allograft segments were subjected to two, four, and eight freeze-thaw cycles and compared biomechanically and histologically with a control group (one freeze-thaw cycle). Two freeze-dried treatments, one after being subjected to one freeze-thaw cycle and the other after being subjected to three freeze-thaw cycles, also were compared with the control group. RESULTS: For all segments, the average ultimate stress was 174 MPa, average modulus was 289 MPa, average energy was 2.00 J, and the average stiffness was 1320 N/mm. The material properties of the freeze-thaw treatment groups were similar to those of the control group: ultimate stress and modulus were a maximum of 16% and 70% different, respectively. Both freeze-dried treatments showed increased stiffness (maximum 53% ± 71%) and energy to failure (maximum 117% ± 137%) but did not exhibit morphologic differences. There were no alterations in the histologic appearance of the bone sections in any group. CONCLUSIONS: Fibular allograft segments can be refrozen safely up to eight times without affecting the biomechanical or morphologic properties. Freeze-dried treatments require further study to determine whether the detected differences are caused by the processing. CLINICAL RELEVANCE: Cryopreserved cortical allografts are thawed by surgeons in preparation for procedures and then occasionally discarded when not used. Refreezing allograft tissues can result in a cost savings because of a reduction in wasted graft material.

Mechanical evaluation of fourth-generation composite femur hybrid locking plate constructs.

Locking compression plates are routinely used for open reduction and internal fixation of fractures. Such plates allow for locking or non-locking screw placement in each hole. A combined use of both types of screw application for stabilization of a fracture is commonly applied and referred to as hybrid internal fixation. Locking screws improve the stability of the fixation construct but at the expense of significant additional cost. This study experimentally analyzes various combinations of locking and non-locking screws under simultaneous axial and torsional loading to determine the optimal hybrid locking plate-screw construct in a fourth generation composite femur. Clinically it is necessary to ensure adequate fixation stability in a worse case fracture-bone quality scenario. A locking screw near the fracture gap increased the axial and torsional strength of the locked plate system. Greater removal torque remained in non-locked screws adjacent to locked screws compared to an all non-locking screws control group.

The effects of magnetic resonance imaging on surgical staples: an experimental analysis.

BACKGROUND: Surgical staples are commonplace in repairing surgical incisions. Staples allow for expeditious closure and removal compared with suture materials. However, there are clinical concerns when obtaining a magnetic resonance imaging (MRI) scan with staples present. This study examined two issues related to MRI scanning in the presence of surgical staples: skin surface temperature change and staple displacement. METHODS: Thirty pig feet had 3-cm surgical incisions repaired with five surgical staples. Once placed, each skin staple position was marked for later referencing. A surface temperature laser device recorded prescan skin surface temperature. A 35-minute MRI scan was performed with a 1.5-Tesla magnet and standard knee coil for each pig foot. Immediately afterward, the skin surface temperature and displacement measurements were recorded. The paired t test was used to analyze temperature change from prescan to postscan. RESULTS: The prescan mean temperature was 16.45°C (standard deviation: 0.70°C), and the range was 14.60°C to 18.20°C. After scanning, the mean temperature was 16.02°C (standard deviation: 0.63°C), and the range was 15.00°C to 17.60°C. The decrease of 0.43°C in skin surface temperature was statistically significant (p=0.001). No change in staple position was measurable or evident by visual inspection for any of the pig feet. CONCLUSION: This study found no increase in skin surface temperature or displacement of staple position after a standard extremity MRI scan. Based on our findings, MRI scanning in the presence of stainless steel surgical staples seems safe.

Biomechanical comparison of a proximal humeral locking plate using two methods of head fixation.

HYPOTHESIS: Locking plates have emerged as the implant of choice for stabilization of proximal humeral fractures. The biomechanical properties of a locked plating system using smooth pegs vs threaded screws for fixation of the humeral head were compared to test the hypothesis that there would be no biomechanical difference between pegs and threaded screws. MATERIALS AND METHODS: Sixteen pairs of fresh frozen cadaveric humeri were randomized to have a surgical neck gap osteotomy stabilized with a locked plate using threaded screws (n=8) or smooth pegs (n=8). The intact contralateral humerus served as a control. Each specimen was tested with simultaneous cyclic axial compression (40 Nm) and torsion (both +/-2 Nm and +/-5 Nm) for 6000 cycles. All specimens were loaded to failure. Interfragmentary motion and load-displacement curves were analyzed to identify differences between the groups. Our data were then compared to previously published forces across the glenohumeral joint to provide evidence based recommendations for postoperative use of the shoulder. RESULTS: There was a statistically significant difference between test specimens and their paired control (P < .001) in cyclic testing and load to failure. Differences between the smooth pegs and threaded screws were not statistically significant. DISCUSSION: There is no biomechanical difference between locked smooth pegs and locked threaded screws for proximal fragment fixation in an unstable 2-part proximal humeral fracture model. CONCLUSION: Our study contributes to the published evidence evaluating forces across the glenohumeral joint and suggests that early use of the affected extremity for simple activities of daily living may be safe. Use of the arm for assisted ambulation requiring a crutch, cane, walker, or wheelchair should be determined on a case-by-case basis.

Use of the Reamer-Irrigator-Aspirator for bone graft harvest: a mechanical comparison of three starting points in cadaveric femurs.

OBJECTIVES: The mechanical behavior of cadaveric femurs after intramedullary reaming using the Reamer-Irrigator-Aspirator (RIA) for autogenous bone graft harvest has not been fully described. We hypothesized that reamed femurs, regardless of starting point, would adequately withstand cyclic loading simulating postoperative single-leg stance. METHODS: Twenty-one cadaveric pairs were randomly assigned to one of three groups based on starting point: Group 1 (trochanteric), Group 2 (piriformis fossa), and Group 3 (retrograde). Each femur underwent dual-energy x-ray absorptiometry scanning and radiographs. Each test femur was reamed to 15 mm using the RIA with the contralateral femur serving as the control. The specimens were loaded to 1400 N of axial compression with 2 degrees simultaneous torsion for 10,000 cycles. If the femur survived cyclic loading, it was then loaded to failure in axial compression. Comparisons regarding survival of cyclic loading were made using Fisher exact test. RESULTS: No differences were seen between groups regarding age, sex, and T-score. The mean T-score for the femurs was -2.531 +/- 1.372. Overall, 18 of 21 (86%) test femurs and 20 of 21 (95%) control femurs withstood cyclic loading (P = 0.606). Statistical significance was not reached for the three pairwise comparisons between test groups. The femurs failed in patterns consistent with simple pertrochanteric, basicervical, midcervical, or subcapital fractures. CONCLUSIONS: Intramedullary reaming for bone graft harvest using the RIA without subsequent intramedullary stabilization did not significantly degrade the mechanical behavior of cadaveric femurs in simulated single-leg stance regardless of reamer starting point. It appears safe to allow single-leg stance weightbearing on a reamed, unstabilized femur after bone graft harvesting using the RIA.

Bladder incarceration following anterior external fixation of a traumatic pubic symphysis diastasis treated with immediate open reduction and internal fixation.

Anterior pelvic ring disruptions are often associated with injuries to the genitourinary structures with the potential for considerable resultant morbidity. Herniation of the bladder into the symphyseal region after injury with subsequent entrapment upon reduction of the symphyseal diastasis has seldom been reported in the literature. We report such a case involving bladder herniation and subsequent entrapment after attempted closed reduction with anterior pelvic external fixation immediately treated with open reduction and internal fixation along with a review of the literature.

Time-dependent contamination of opened sterile operating-room trays.

BACKGROUND: There are no clear guidelines for how long a sterile operating-room tray can be exposed to the open environment before the contamination risk becomes unacceptable. The purpose of this study was to determine the time until first contamination and the rate of time-dependent contamination of sterile trays that had been opened in a controlled operating-room environment. We also examined the effect of operating-room traffic on the contamination rate. METHODS: Forty-five sterile trays were opened in a positive-air-flow operating room. The trays were randomly assigned to three groups. All trays were opened with use of sterile technique and were exposed for four hours. Culture specimens were obtained immediately after opening and every thirty minutes thereafter during the study period. Group 1 consisted of fifteen trays that were opened and left uncovered in a locked operating room (i.e., one with no traffic). Group 2 was identical to Group 1 with the addition of single-person traffic flowing in and out of the operating room from a nonsterile corridor every ten minutes. Group 3 included fifteen trays that were opened, immediately covered with a sterile surgical towel, and then left uncovered in a locked operating room (i.e., one with no traffic). RESULTS: Three of the thirty uncovered trays (one left in the operating room with traffic and two left in the room with no traffic) were found to be contaminated immediately after opening. After those three trays were eliminated, the contamination rates recorded for the twenty-seven uncovered trays were 4% (one tray) at thirty minutes, 15% (four) at one hour, 22% (six) at two hours, 26% (seven) at three hours, and 30% (eight) at four hours. There was no difference in survival time (p = 0.47) or contamination rate (p = 0.69) between the uncovered trays in the room with traffic and those in the room without traffic. The covered trays were not contaminated during the testing period. The survival time for those trays was significantly longer (p = 0.03) and the contamination rate was significantly lower (p = 0.02) than those for the uncovered trays. CONCLUSIONS: Culture positivity correlated directly with the duration of open exposure of the uncovered operating-room trays. Light traffic in the operating room appeared to have no impact on the contamination risk. Coverage of surgical trays with a sterile towel significantly reduced the contamination risk.

Safe zone for anterior cortical perforation of the ulna during tension-band wire fixation: a magnetic resonance imaging analysis.

Placing K-wires obliquely through the anterior ulnar cortex is a common modification of traditional olecranon tension-band wiring. Wire tip protrusion, however, risks injury to adjacent neurovascular structures and may impede forearm rotation. This study examines the proximity of neurovascular structures to the anterior proximal ulnar cortex. The anatomy of 47 adult elbows was examined through magnetic resonance imaging. A radiologist measured the spatial relationship of 6 neurovascular structures to a mid-sagittal reference point 1.5 cm distal to the coronoid on the anterior surface of the ulna. Distance and angular measurements were made in the transverse plane of the reference point. Within a reasonable arc of K-wire placement, the ulnar artery and median nerve were at greatest risk yet were still beyond 10 mm from the anterior ulnar cortex. To avoid iatrogenic neurovascular injury during tension-band wiring of the olecranon, protrusion of wire tips beyond the anterior ulnar cortex should be no more than 1 cm at a distance of 1.5 cm distal to the coronoid.

Overview of the locking compression plate and its clinical applications in fracture healing.

Open reduction and internal fixation of fractures involves the use of metallic implants to support bone reduction. This procedure is often used in situations in which adequate alignment and stability of the bone cannot be achieved using nonsurgical methods such as casting. The locking compression plate is a contemporary implant that allows for both conventional screw placement (using nonlocking screws) and locking screw placement (where screw heads lock into the plate at a predetermined angle). This allows for greater versatility in the application of internal fixation. This article presents a general overview of locking compression plate application along with a review of the locking compression plate literature.