Background: Nonunions of an osteotomy site are the most reported surgical complication following periacetabular osteotomy (PAO) for the treatment of symptomatic acetabular dysplasia. Identification of patient-specific risk factors for nonunion remains an ongoing area of research. Objective: To identify patient-specific risk factors associated with nonunion after PAO for symptomatic hip dysplasia at approximately one year postoperatively. Methods: We retrospectively identified 103 hips (94 patients) that underwent Bernese PAO at our institution between December 2017 and May 2023. We collected patient demographics, Beighton score, lateral center-edge angle, anterior center-edge angle, femoral version, and preoperative vitamin D status. We also obtained comprehensive HU measurements at the femoral neck, as described by Christensen et al. (2019), from preoperative low-dose radiation CT scans. Nonunion was defined as noncontiguous osseous healing across any osteotomy site on 12-month postoperative radiographs. 12 hips were exluded due to insufficient postoperative radiographs. We used logistic regression to assess the relationships between odds of nonunion and potential demographic and radiographic predictor variables in univariate analyses. Results: Final analysis included 91 hips (83 patients). 84.4% of patients were female, average age was 29.20 ± 9.59 years, and average BMI was 25.35 ± 4.27 kg/m2. The nonunion rate was 14.3%. Age (27.15 ± 9.28 years healed versus 37.07 ± 7.75 years nonunion; OR 1.14; 95% CI, 1.03-1.25; p=0.02) and BMI (24.64 ± 4.02 kg/m2 healed versus 28.39 ± 4.00 kg/m2; OR 1.24; 95% CI, 1.03-1.48; p=0.02) were significantly higher in the nonunion group. Comprehensive HU measurement at the femoral neck was significantly lower in the nonunion group (218.26 ± 75.10 HU healed versus 156.41 ± 43.01 HU nonunion; OR 0.981; 95% CI, 0.96-0.99; p=0.03). Beighton score (p=0.31), lateral center-edge angle (p=0.62), anterior center-edge angle (p=0.22), femoral version (p=0.28) and preoperative vitamin D level (p=0.21) were not significantly different between the healed and nonunion groups. Conclusions: Decreased bone attenuation on low-dose radiation CT scan, increased age, and high BMI can independently predict nonunion after PAO for acetabular dysplasia. Surgeons should consider these factors and assess bone health using preoperative CT to better inform patients about the risk of nonunion.

Introduction A minority of geriatric hip fracture patients pursue non-operative treatment. Compared with surgical patients, non-operative patients have higher mortality rates. However, patient satisfaction following non-operative vs operative treatment has not been investigated extensively. The purpose of this study was to compare satisfaction among non-operatively vs operatively treated hip fracture patients. Methods We identified patients aged 60+ years with proximal femur fractures treated over a 10-year period. Excluded were patients with isolated greater/lesser trochanteric fractures. Patients or relatives were asked to complete a 6-question survey about their treatment satisfaction. Results Survey responses from 56 operative and 28 non-operative patients were recorded. Overall, 91.1% of operative and 82.1% of non-operative patients were satisfied with their treatment course ( P = 0.260). However, only 71.4% of non-operative patients were satisfied with treatment option explanations vs 83.9% of operative patients ( P = 0.014). While only 64.3% of non-operative respondents were satisfied with the ultimate treatment outcome (vs 85.7% of operative patients, P = 0.025), 89.3% of patients in each cohort would choose the same treatment plan again. Discussion Our findings highlight the complexity of defining patient satisfaction, particularly in a geriatric hip fracture population. Unlike previous studies, we chose a direct approach to quantifying patient satisfaction by asking participants specifically about satisfaction with treatment outcome and the overall treatment course. Additional survey questions were then included to assess factors considered important in treatment satisfaction, such as health care provider treatment explanations, post-treatment mobility, and palliative care service involvement. Conclusions We identified significant differences between non-operatively and operatively treated geriatric hip fracture patients regarding satisfaction with the explanation of treatment options, and ultimate treatment outcomes. There was no significant difference in overall satisfaction with the treatment course or likelihood of choosing the same treatment again. Further research investigating patient satisfaction following geriatric hip fracture treatment is warranted.

Aneurysmal bone cysts (ABCs) in the periacetabular region can be challenging to treat because they create unique problems, given their proximity to articular cartilage and a significant weight bearing surface. This case series details the assessment and treatment of four periacetabular ABCs with a review of pertinent current literature. Treatment approaches used include curettage with 6% phenol chemical adjuvant, type III hemipelvectomy, serial image-guided sclerotherapy injections, and in one case, an exostotic lesion was treated with hip arthroscopy.

Background: Heterotopic ossification (HO), or the abnormal formation of bone in extra-skeletal tissue, is a well-known complication of orthopedic trauma, tendon avulsions, chronic injuries, spinal cord injuries, and soft tissue damage from surgery. Heterotopic ossification commonly develops at the direct or indirect head of the rectus femoris. Athletes are especially susceptible to chronic microtearing and acute tendon avulsion, which may result in HO. When HO develops in the setting of concurrent intra-articular hip pathology, it may be amendable to arthroscopic excision, depending on its size and location. Indications: Heterotopic ossification that develops adjacent to the hip joint can affect range of motion of the joint and is often a source of pain. Arthroscopic excision is indicated when the HO that develops within or about the hip joint is symptomatic and is of a location and size that it can be reached and excised arthroscopically. Technique Description: In this technical note, we describe our method to excise HO using initial arthroscopic surgery to address femoroacetabular impingement syndrome (FAIS) and perform initial dissection of the HO fragment. Heterotopic ossification resection was then completed via an anterior open approach followed by reconstruction of the rectus femoris origin with Achilles allograft. This is followed by our HO prophylaxis protocol of indomethacin 75 mg daily for 4 days, followed by naproxen 500 mg 2 times daily through postoperative day 30, although many other regimens exist for HO prophylaxis. Results: Using arthroscopy for the removal of symptomatic HO at the time of surgery allows for the management of concomitant intra-articular pathology and efficient and precise dissection of the undersurface of the HO fragment. Discussion/Conclusion: Heterotopic ossification is a well-characterized complication of soft tissue damage, including tendon avulsion, trauma, previous surgery, and chronic microtear of the hip musculature. Oftentimes, HO develops in a location that can be reached arthroscopically. Surgeons should consider combining intra-articular arthroscopic surgery with arthroscopic excision of HO when appropriate, noting that there are many advantages to arthroscopic removal when compared with open procedures. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Background: Femoral version abnormalities can contribute to intra-articular hip pathology. Combined hip arthroscopy with femoral derotational osteotomy (FDRO) has been shown to successfully treat those with intra-articular hip pathology with excessive anteversion or retroversion of the femur. Indications: We describe the technique for combined hip arthroscopy and FDRO in patients with symptomatic intra-articular hip pathology in the setting of excessive anteversion or retroversion of the femur. Technique Description: Hip arthroscopy is performed using standard anterolateral, modified mid-anterior, and distal anterolateral accessory portals. The labrum is repaired using a narrow diameter suture. Femoroplasty is performed with utilization of fluoroscopic imaging to assess resection. Dynamic flexion is performed as a final check of adequacy of resection. Capsular closure is performed in all cases. After hip arthroscopy, the patient is repositioned on a radiolucent table. A piriformis start point is obtained with a guide pin followed by standard opening reaming and ball-tipped guidewire placement. A femoral osteotomy is made just proximal to the isthmus and made through a lateral approach to the femur. Two K-wires are placed distal and proximal to the osteotomy site. A goniometer is then used to measure rotation. A drill is used to perforate the cortex circumferentially at the osteotomy site. After standard reaming, a sagittal saw is then used to start the osteotomy cut followed by an osteotome. An intramedullary nail is inserted over a ball-tipped guidewire while rotational reduction is assessed from the foot of the operating table. Distal interlocking screws are placed, and the nail is backslapped to create compression at the osteotomy site prior to placing proximal interlocking screws. Results: Recent studies show improved hip outcome scores in patients who undergo concomitant hip arthroscopy and FDRO for symptomatic abnormal femoral version. Discussion/Conclusion: Identifying patients who would benefit from concomitant surgeries requires thorough preoperative evaluation. Correct identification and treatment of these patients leads to improved outcomes. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Objective: To compare the mortality rate between geriatric patients with hip fracture treated nonoperatively and a matched cohort treated operatively. Design: Retrospective Observational Matched Cohort Study. Setting: Academic Level 1 Trauma Center. Patients: Geriatric patients who sustained femoral neck and intertrochanteric/peritrochanteric fractures, excluding isolated greater trochanteric fractures. All patients older than 65 years with hip fractures over a 10-year period were identified. Operative patients were matched at a 2:1 ratio, when possible, to nonoperative patients based on Charlson Comorbidity Index and American Society of Anesthesiologists score. Intervention: Nonoperative treatment or operative treatment (femoral neck fractures: cannulated screw fixation or hemiarthroplasty; intertrochanteric/peritrochanteric fractures: sliding hip screw or cephalomedullary nail fixation; or proximal femoral locking plate). Main Outcomes: Mortality calculated at 30 and 90 days, and 1-year after injury. Mortality was compared between groups using logistic regression while controlling for age, CVA/TIA, and dementia. Results: Seven hundred seventy-two patients (171 nonoperative and 601 operative) were initially identified. After applying the matching algorithm, 128 nonoperative and 239 operative patients were included in the analysis. There were no significant differences in age, sex, Charlson Comorbidity Index, or American Society of Anesthesiologists score between the cohorts. Nonoperative patients had a significantly higher 1-year mortality rate than operative patients [46.1% vs. 18.0%, Odds Ratio (95% confidence interval): 3.85 (2.34–6.41), P < 0.001]. Conclusions: Geriatric patients with hip fracture treated nonoperatively had a 1-year mortality rate of 46.1%, more than double the rate among operative patients. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background: Modern external ring fixation has been hypothesized to reduce complications requiring hospital readmission compared with internal fixation when treating patients with high-energy open tibial shaft fractures. In this study, the 1-year probability of a major limb complication was compared between external and internal fixation of severe open tibial fractures. Methods: This multicenter randomized clinical trial included patients 18 to 64 years of age with severe open tibial shaft fractures randomly assigned to either modern external ring fixation (n = 127) or internal fixation (n = 133). The primary outcome was a major limb complication within 365 days after randomization; these complications included amputation, infection, a soft-tissue problem, nonunion, malunion, and a loss of reduction/implant failure. Results: Of 260 randomized patients, 254 were included in the final analysis. Their mean age (standard deviation) was 39 (13) years; 214 (84%) were men. The probability of at least 1 major limb complication was higher for external fixation (62.1% [95% confidence interval (CI): 53.4% to 70.8%]) than internal fixation (43.7% [95% CI: 35.5% to 52.9%]), with a risk difference of 18.4% (95% CI: 5.8% to 30.4%); p = 0.005). The most notable difference was in loss of reduction/implant failure, the rate of which was higher for external fixation (risk difference: 14.4% [95% CI: 7.0% to 21.6%]; p = 0.002). There was no appreciable difference in the probability of deep infection between external fixation (26.1%) and internal fixation (29.7%) (risk difference: -3.5% [95% CI: -14.8% to 7.8%]; p = 0.54). There were also no appreciable differences in the probabilities of amputation, nonunion, soft-tissue problems, malunion, or fracture healing between the groups. Conclusions: These results argue against routine use of modern external ring fixation for the treatment of these severe open tibial fractures.

Background: Supplemental perioperative oxygen is a low-cost intervention theorized to reduce the risk of surgical site infections, but its effect among patients undergoing surgery for a tibial plateau, tibial pilon, or calcaneal fracture is unknown. We aimed to determine the effectiveness of a high fraction of inspired oxygen (FiO(2), 80%) versus low FiO(2) (30%) in reducing surgical site infections in these patients. Methods: A randomized controlled trial was conducted at 29 U.S. trauma centers. We enrolled 1,231 patients who were 18 to 80 years of age and had a tibial plateau, tibial pilon, or calcaneal fracture and were thought to be at elevated risk for infection based on their injury characteristics. Patients were randomized to receive 80% FiO(2) (treatment group) or 30% FiO(2) (control group) in the operating room and for up to 2 hours in the recovery room. The primary outcome was a composite of either deep surgical site infection (treated with surgery) or superficial surgical site infection (treated with antibiotics alone) within 182 days following definitive fixation. Secondary outcomes included these surgical site infections at 90 and 365 days after surgery. Results: The modified intention-to-treat analysis included 1,136 patients with 94% of expected follow-up through 182 days. Surgical site infection occurred in 40 (7.0%) of the patients in the treatment group and 60 (10.7%) of the patients in the control group (relative risk [RR], 0.65; 95% confidence interval [CI], 0.45 to 0.96; risk difference [RD], -3.8%; 95% CI, -7.2% to -0.4%; p = 0.03). The treatment intervention demonstrated a similar effect at 90 days (RR, 0.59; 95% CI, 0.37 to 0.93) and 365 days (RR, 0.62; 95% CI, 0.44 to 0.87). Secondary analyses demonstrated that the effect was driven by a reduction in superficial surgical site infections. Conclusions: Among tibial plateau, pilon, or calcaneal fracture patients at elevated risk for surgical site infection, a high perioperative FiO(2) lowered the risk of surgical site infection. The findings support the use of this intervention, although the benefit appears to mostly be in reduction of superficial infections.

Coxa profunda presents a unique challenge in surgical treatment approach given global acetabular overcoverage. Arthroscopic treatment can be fraught with difficulty obtaining hip distraction for safe arthroscopic instrumentation, and limited arthroscopic access may prevent sufficient osseous resection of the excess acetabular rim. Although hip arthroscopy use has increased markedly over the past decades for all types of hip pathology, coxa profunda may represent one unique indication for surgical hip dislocation. This technique describes open surgical hip dislocation, rim resection, femoral osteoplasty, and labral reconstruction using anterior tibialis allograft for coxa profunda with combined-type femoroacetabular impingement syndrome and labral ossification.

In this Technical Note, we discuss the combined hip arthroscopy and periacetabular osteotomy (PAO) for the treatment of symptomatic hip dysplasia, with a focus on the technique we use for the PAO. We identify modifications that can be made during the arthroscopic portion of the procedure to assist in the PAO dissection, including arthroscopic capsular closure and arthroscopic elevation of the iliocapsularis muscle off the capsule, which allows for expedited open exposure during the PAO.

Abstract. Objectives:. To assess the impact of various reduction techniques on postoperative alignment following intramedullary nail (IMN) fixation of tibial shaft fractures. Design:. Retrospective comparative study. Setting:. Level I trauma center. Patients:. Four hundred twenty-eight adult patients who underwent IMN fixation of a tibial shaft fracture between 2008 and 2017. Intervention:. IMN fixation with use of one or more of the following reduction techniques: manual reduction, traveling traction, percutaneous clamps, provisional plating, or blocking screws. Main outcome measures:. Immediate postoperative coronal and sagittal plane alignment, measured as deviation from anatomic axis (DFAA); coronal and sagittal plane malalignment (defined as DFAA >5° in either plane). Results:. Four hundred twenty-eight patients met inclusion criteria. Manual reduction (MR) alone was used in 11% of fractures, and adjunctive reduction aids were used for the remaining 89%. After controlling for age, BMI, and fracture location, the use of traveling traction (TT) with or without percutaneous clamping (PC) resulted in significantly improved coronal plane alignment compared to MR alone (TT: 3.4°, TT+PC: 3.2°, MR: 4.5°, P = .007 and P = .01, respectively). Using TT+PC resulted in the lowest rate of coronal plane malalignment (13% vs 39% with MR alone, P = .01), and using any adjunctive reduction technique resulted in decreased malalignment rates compared to MR (24% vs 39%, P = .02). No difference was observed in sagittal plane alignment between reduction techniques. Intraclass correlation coefficient (ICC) results indicated excellent intraobserver reliability on both planes (both ICC>0.85), good inter-observer reliability in the coronal plane (ICC = 0.7), and poor inter-observer reliability in the sagittal plane (ICC = 0.05). Conclusions:. The use of adjunctive reduction techniques during IMN fixation of tibia fractures is associated with a lower incidence of coronal plane malalignment when compared to manual reduction alone. Level of evidence:. Therapeutic Level III.

Heterotopic ossification (HO) can occur as a complication of various pathologies affecting the hip including trauma, tendon avulsions, chronic injury, spinal cord injury, and soft-tissue disruption caused by surgery. When HO is present alongside intra-articular hip pathology such as femoroacetabular impingement syndrome (FAIS) or labral pathology, consideration should be made to combine the surgical excision of the HO with the FAIS decompression or labral repair if the location and size of the HO is appropriate for arthroscopic excision. Often times, the HO is located in such a position that any central compartment work can be completed before turning to the HO excision. If an open approach is required, the modified Gibson approach can be used for lateral hip access, whereas the Smith-Petersen approach provides anterior hip access. In this Technical Note we discuss arthroscopic techniques for excision of HO in the setting of concomitant FAIS, with discussion of when HO excision occurs in relation to cam decompression and labral repair, and mention tips on how to approach HO excision through an open approach.

The purpose of this study was to determine the feasibility and clinical benefits of using 3D-printed hemipelvis models for periacetabular osteotomy preoperative planning in the treatment of hip dysplasia. This retrospective study included 28 consecutive cases in 26 patients, with two bilateral cases, who underwent periacetabular osteotomy between January 2017 and February 2020 and had routine radiographs, CT and MR imaging. Of these, 14 cases [mean patient age 30.7 (SD 8.4) years, 11 female] had routine preoperative imaging, and 14 cases [mean patient age 28.0 (SD 8.7) years, 13 female] had routine preoperative imaging and creation of a full-scale 3D-printed hemipelvis model from the CT data. The expected surgical cuts were performed on the 3D-printed models. All patients underwent Bernese periacetabular osteotomy. Operative times, including time to achieve proper acetabular position and total periacetabular osteotomy time, fluoroscopy radiation dose and estimated total blood loss were compiled. ANOVA compared outcome variables between the two patient groups, controlling for possible confounders. On average, patients who had additional preoperative planning using the 3D-printed model had a 5.5-min reduction in time to achieve proper acetabular position and a 14.5-min reduction in total periacetabular osteotomy time; however, these changes were not statistically significant (P = 0.526 and 0.151, respectively). No significant difference was identified in fluoroscopy radiation dose or total blood loss. Detailed surgical planning for periacetabular osteotomy using 3D-printed models is feasible using widely available and affordable technology and shows promise to improve surgical efficiency.

OBJECTIVES:To identify the methicillin-resistant Staphylococcus aureus (MRSA) carrier rate among surgical patients on an orthopaedic trauma service and to determine whether screening is an effective tool for reducing postoperative MRSA infection in this population.DESIGN:Prospective.SETTING:Level 1 trauma center.PATIENTS/PARTICIPANTS:Two hundred forty-eight patients with operatively managed orthopaedic trauma conditions during the study period. Two hundred three patients (82%) had acute orthopaedic trauma injuries. Forty-five patients (18%) underwent surgery for a nonacute orthopaedic trauma condition, including 36 elective procedures and 9 procedures to address infection.INTERVENTION:MRSA screening protocol, preoperative antibiotics per protocol.MAIN OUTCOME MEASUREMENTS:MRSA carrier rate, overall infection rate, MRSA infection rate.RESULTS:Our screening captured 71% (175/248) of operatively treated orthopaedic trauma patients during the study period. The overall MRSA carrier rate was 3.4% (6/175). When separated by group, the acute orthopaedic trauma cohort had an MRSA carrier rate of 1.4% (2/143), and neither MRSA-positive patient developed a surgical site infection. Only one MRSA infection occurred in the acute orthopaedic trauma cohort. The nonacute group had a significantly higher MRSA carrier rate of 12.5% (4/32, P = 0.01), and the elective group had the highest MRSA carrier rate of 15.4% (4/26, P < 0.01). The odds ratio of MRSA colonization was 10.1 in the nonacute group (95% confidence interval, 1.87-75.2) and 12.8 for true elective group (95% confidence interval, 2.36-96.5) when compared with the acute orthopaedic trauma cohort.CONCLUSIONS:There was a low MRSA colonization rate (1.4%) among patients presenting to our institution for acute fracture care. Patients undergoing elective surgery for fracture-related conditions such as nonunion, malunion, revision surgery, or implant removal have a significantly higher MRSA carrier rate (15.4%) and therefore may benefit from MRSA screening. Our results do not support routine vancomycin administration for orthopaedic trauma patients whose MRSA status is not known at the time of surgery.LEVEL OF EVIDENCE:Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

OBJECTIVE To describe the inciting events leading to urosymphyseal fistulas (UFs) and pubic osteomyelitis (PO) in patients who had radiation-induced urethral strictures. METHODS We retrospectively reviewed patients who underwent simultaneous pubic debridement, simple cystectomy, and urinary diversion for refractory UF and PO from 2014 to 2016. We investigated inciting events leading to UF, as well as patient presenting symptoms, diagnosis, management, and outcomes. RESULTS Five patients were identified over a 2-year period. All patients had a previous history of radiation for prostate cancer. The median age was 67 years. All patients developed UF and PO after endoscopic intervention for urethral stricture. The number of endoscopic interventions per patient for stricture ranged from 1 to 7, including serial dilation, balloon dilation, and urethrotomy. Sterile urine cultures were obtained before all endoscopic interventions. All patients had pelvic pain with ambulation and recurrent urinary tract infections at presentation. Patients were diagnosed using a combination of retrograde urethrography and magnetic resonance imaging. Simultaneous pubic debridement with simple cystectomy and diversion was used for management in all cases. One patient died postoperatively with the remainder recovering well without PO or fistula recurrence, with a median follow-up of 16 months. CONCLUSION UF can occur as a complication of endoscopic treatment of posterior urethral stricture in patients with a history of radiation therapy for prostate cancer. This study demonstrates that UF and PO may develop even with minimally traumatic procedures and sterile urine. All patients treated for posterior stricture must be considered at risk of development of fistulas and osteomyelitis. (C) 2017 Elsevier Inc.

Open pilon fracture management and treatment poses a significant challenge to orthopedic surgeons. The purpose of this study was to determine patient outcomes for open pilon fractures based on wound complication and infection rates, as well as subjective outcome instruments.

Background This case series report discusses patients presenting with hemorrhage and hemodymanic compromise due to severe pelvic fractures and undergoing intraoperative angioembolization (IAE) with other resuscitative procedures. Methods We used portable digital subtraction fluoroscopy units for IAE in patients with severe pelvic hemorrhage and hemodynamic instability (5/03-4/09). Data was collected on demographics, injury severity, resource utilization, and outcomes at our Level 1 trauma center. Results There were 6,538 adult admissions with 912 having pelvic fractures and 65 of these undergoing pelvic angioembolization. Twelve hemodynamically compromised patients (10 males, 2 females) had intraoperative pelvic angiography (age: 22-79 years; mean 51.3 ± 17.4). Injury severity score (ISS) was 37.5 ± 8.4 (22-50). Mean emergency department (ED) length of stay (LOS) was 57.4 min ± 47.9 with 10 patients transported directly to the OR and 2 to the SICU prior to OR. Ten of 12 patients underwent exploratory laparotomy followed by angioembolization. Mortality was 50%. Among the 6 survivors (ISS 22 - 50), all had a pre-op CT scan, five had an initial base deficit <13, and four were transfused ≤ 6 units pre-incision/pre-procedure. Four of the 6 survivors had unilateral embolization. In contrast, all 6 non-survivors (ISS 29-41) required massive transfusion prior to OR (>6 units PRBCs) with 4 having a based deficit >13. Three of these patients bypassed CT and five underwent bilateral internal iliac embolization (BIIE). Conclusions IAE for severe pelvic hemorrhage can be successfully performed concurrently with exploratory laparotomy, pelvic packing or other resuscitative procedures. Patients most likely to benefit have a base deficit <13, and do not require massive transfusion prior to IAE or suffer from a vertically unstable pelvis fracture.

Introduction: Numerous studies have demonstrated that administration of non-steroidal anti-inflammatory medications (NSAIDs) results in delayed healing and decreased strength of post -fracture bone (1-3). Many orthopaedists hesitate to prescribe or continue anti-inflammatory medications for fracture or postoperative pain control due to this putative inhibitory effect. Recently, COX-2 specific inhibitors have shown equivalent analgesic efficacy vs. conventional NSAIDs with fewer unwanted side effects (4, 5). COX-2 specific inhibitors primarily inhibit production of PGE2, a prostaglandin believed to play a primary role in the inflammatory cascade. The goal of this study was to determine whether COX-2 specific inhibitors affected fracture healing to the same degree as conventional NSAIDs. To assess changes in fracture healing and strength as a function of COX-2 inhibitor administration, we determined biomechanical and radiographic properties at 4,8, and 12 weeks after nondisplaced femur fracture in the adult rat. Methods: All procedures conformed to the guidelines of the Penn State IACUC(#2001-110). 57 adult male Wistar rats weighing 300 g were randomly placed into three groups of 19 rats. All three groups underwent nondisplaced right femur fractures according to the method of Bonnarens and Einhorn (6). Left femurs were pinned and remained intact to serve as controls. Group I received no drug, Group II received indomethacin at 1 mg/kg/day and Group III received celecoxib at 3 mg/kg/day p.o. starting postoperative day (POD) 1. These doses are in the range of average recommended therapeutic doses (3, 7). The administered dose of drug was mixed with chocolate and fed to each rat daily to assure consistent and accurate dosing. Fractures from each subgroup were analyzed at the 4, 8, and 12 week. Radiographic analysis was performed to assess callus maturity and bridging bone formation. Callus strength was assessed by 3-point bending and compared to contralateral control, and stage of fracture union was determined by stiffness and failure location according to the classification by White et al. (8). Data were grouped and analyzed using standard GLM ANOVAs with SNK post -hoc comparisons for all groups and unpaired t -tests between groups with an a priori significance level of 0.05. Results: At 4 weeks, the indomethacin group had significantly less stiffness (Figure 1) and strength (Figure 2) relative to vector-treated controls. Strength was expressed as bending moment (M) to failure. The indomethacin group also demonstrated morphological evidence of delayed healing relative to the celecoxib and vector-treated groups (not shown). Radiographically, the indomethacin group had both decreased callus formation and decreased bridging bone formation, though this result was not significant with the numbers available (Figure 3). There were no significant differences between the celecoxib group and vectortreated controls at 4, 8, and 12 weeks. Though the celecoxib femurs appeared to have more fibrous tissue than controls at 4 and 8 weeks, radiographic callus formation, mechanical strength and stiffness were not signifcantly different. By 12 weeks, there were no significant radiographic, morphological or biomechanical differences between any of the groups. 0 0.5 1 1.5 2