Purpose: To determine the effect of delay to surgery on functional outcome in patients with operatively-treated acetabular fractures.

Method: Two hundred and thirty-two patients with acetabular fractures were identified from a pelvic trauma database. Functional outcome data was assessed using the validated Musculoskeletal Functional Assessment (MFA) and the Short Form 36 (SF-36) surveys in 162 patients. After 1997, functional outcome scores were collected prospectively at 6 months, 1 year and 2 years (or greater) post-operatively. Functional outcome scores, quality of reduction, and risk of complications were modeled as a function of days of delay to surgery via multivariate regression analysis adjusting for age, gender, fracture type, and associated injuries.

Results: At 6 months post-operatively, functional outcome scores were significantly worse with increasing delay to surgery. A delay of between 7 and 13 days or 14 or more days decreased the SF-36 physical component (PCS) z-scores by 0.75 (95% CI: −1.41 to −0.09) and 1.5 standard deviations (95% CI: −2.43 to −0.56) respectively. Delay of 14 or more days was associated with a worsening of the lower extremity (Move) subsection of the MFA by 18.6 points (95% CI: 3.3 to 33.8). Delay to surgery was associated with a significantly higher risk of poor reduction among those with available radiographic follow-up (n=67). Delay 14 days or more was associated with a 5 times (95% CI?.04 to 23.99) greater risk of a post operative step or gap over 2 mm. Delay to surgery was associated with an increase in thrombotic complications. In those patients who were diagnosed with a pulmonary embolism(PE) the mean delay was 11.3 days versus 7.3 days for the rest of the cohort (p=0.01). For patients with a deep vein thrombosis (DVT) average delay was 14.1 days versus 7.1 days (p=0.01).

Conclusion: Delay to surgery is associated with worsening functional outcome scores after as little as 7 days of delay. After 14 days, functional outcomes deteriorate further and radiographic outcomes are negatively influenced. Increased delay also increases risk of thrombotic events. These conclusions underscore the importance of timely treatment for displaced acetabular fractures.

Purpose: The distribution of weight bearing area within the acetabulum is of importance in addressing trauma to the acetabulum, hip joint deformities and causes of osteoarthritis. According to Wolf’s law, bone density can indicate loading patterns experienced. The objective of this study was to characterize distributions of acetabular bone density patterns by regions in the normal population.

Method: CT scans of 22 subjects, mean age 70.6 with no evidence to hip joint pathologies were analysed. Bone density distribution maps were generated within AmiraDEV4.1 image analysis software using custom written plugins (Visage Imaging, Carlsbad, USA). Acetabular cup surfaces were semi-automatically segmented from the reconstructed CT volumes with an atlas-based approach. The acetabular cups were expanded 2.5 mm into the acetabular bone, and surface bone densities were calculated as the average bone density within ±2.5mm. The distribution maps were analysed using zones to spatially classify areas of high and low bone density in a healthy population. The acetabular cups were aligned using the acetabular rim plane that was landmarked, and by rotating the cups, such that a 900 abduction angle and a 00 anteversion angle were achieved. The grid used was divided to quadrants, and subdivided into radial thirds of the average rim radius. The correspondence of left and right density maps was investigated by comparing the average bone density in corresponding zones and across the population.

Results: High bone densities were found around the roof of the acetabulum aligning with the femoral mechanical axis during standing. The highest average bone density were found to be the superior and posterior walls of the acetabulum, corresponding to regions 8, 9, and 12 compared to other regions of the acetabuli (P< 0.01). A strong correlation was found between left and right sides within subjects (R=0.91, P< 0.05); and weaker correlation was also found for overall average bone density, (R=0.77, P< 0.05).

Conclusion: The location of the zones with the highest average bone density agrees with cadaveral studies of the maximum contact stress in the acetabulum (zones 9 and 12). [1,2]. It may explain why trauma to these areas carries a higher risk for early arthritic changes.

Purpose: Surgery for degenerative lumbar spinal conditions offers tremendous benefit for patients with moderate/severe symptoms failing non-operative treatment. There is little appreciation among referring family physicians (FPs) on factors that identify the ideal surgical candidate. Differences in preferences between patients and physicians leads to wide variation in referrals and impedes the shared decision-making process. Our purpose was to identify the dominant clinical factors influencing patient, FP, and surgeon preferences for lumbar spinal surgery.

Method: We used conjoint analysis, a rigorous method for eliciting preferences, in a mailed survey to all orthopaedic and neurosurgeons, a random sample of FPs, and patients in Ontario to determine the importance that respondents place on decisions for lumbar spinal surgery. We identified six clinical factors (walking tolerance, duration of pain, pain severity, neurological symptoms, typical onset, and dominant location of pain) and presented 16 hypothetical vignettes to participants who rated, on a six-point-scale, their preference for surgery. Data were analyzed using random-effects ordered probit regression models and relative importance of each clinical factor was reported.

Results: We obtained responses from 131 surgeons, 202 FPs, and 164 patients. We demonstrated that despite wide variations in overall responses, all six clinical factors were highly associated with surgical preference (p< 0.01). Surgeons placed the highest importance on the location of pain (34%), followed by pain severity (19%) and walking tolerance (19%). FPs considered neurological symptoms (23%), walking tolerance (20%), pain severity (20%), and typical onset (16%) to all be of similar importance. Pain severity (29%), walking tolerance (29%), and duration of pain (28%) were the most important factors for patients in deciding for surgery. Orthopaedic (over neurosurgical) specialty was statistically associated with a lower preference for surgery (p< 0.047). Older patient age (p< 0.03) and previous surgical consultation (p< 0.03) were both associated with a greater patient preference for considering surgery.

Conclusion: Different preferences for surgery exist between surgeons, FPs and patients. FPs may reduce over- and under-referrals by appreciating surgeons’ importance on location of pain (leg versus back). Surgeons and FPs may improve the shared decision making process by understanding that patients place high importance on duration, severity, and walking tolerance.

Purpose: Among patients with isolated below-knee fractures, venography studies detect deep vein thrombosis (DVT) in 20 – 40%. The clinical relevance of these thrombi is unknown. We conducted the first randomized, double-blind, multicentre study designed to assess the effectiveness and safety of low molecular weight heparin compared to placebo in preventing CIVTE in patients with isolated fractures of the distal leg.

Method: Consecutive patients with fractures of the tibia, fibula or ankle requiring surgery were randomized to dalteparin 5000 U or placebo once daily SC within 72 hours of fracture for 14 + 2 days. Patients were screened using proximal duplex ultrasound at day 14, and followed up at 6 wks and 3 mos. Clinically suspected VTE was investigated using standardized algorithms with central, blinded adjudication.

Results: From August 2002 to October 2006, 134 patients were randomized to dalteparin and 131 to placebo. 98% of patients completed 3 mo follow-up. Overall, 5 patients had CIVTE (2 asymptomatic DVT, 2 symptomatic DVT, 1 nonfatal PE); 2 (1.5%) in the dalteparin arm and 3 (2.3%) on placebo (p=0.68). There were no major bleeds.

Conclusion: The overall incidence of CIVTE after surgically-repaired, isolated tibia, fibula and ankle fractures was so low (1.9%; 95% CI 0.7 to 4.7%), with no observed differences between dalteparin and placebo either for CIVTE or safety, that recruitment was stopped early. This study also demonstrates the large discrepancy between trials that utilize venographic and CIVTE outcomes.

Purpose: We conducted the first, multicentre, prospective cohort study to define the incidence of symptomatic venous thromboembolism (VTE) in patients with tibia and ankle fractures treated conservatively and relatively minor lower leg fractures. The reported incidence of deep vein thrombosis (DVT) using routine venography in patients with lower leg injury requiring cast immobilization is approximately 20–40%, which has lead to the routine use of anticoagulant prophylaxis for several weeks in many such patients. However the vast majority of venographically-detected DVTs are asymptomatic, distal thrombi whose clinical relevance is uncertain. Therefore venography is not the best outcome measure to assess the burden of clinically important VTE.

Method: Consecutive patients with tibia and fibula fractures (treated non-operatively) and patella and foot fractures, (treated operatively or conservatively) were assessed for eligibility at 5 Ontario hospitals. Patients were enrolled after informed consent within 96 hours of injury and were followed prospectively, by telephone, at 2, 6 and 12 weeks. Those with major trauma, active cancer, and previous VTE were excluded. Thromboprophylaxis was not allowed. Education regarding symptoms of VTE was provided at study entry and patients were asked about VTE symptoms at follow up. Suspected VTE was investigated in a standardized manner.

Results: From August 2002 to June 2005, 1200 patients were enrolled from 2446 consecutively screened patients. 98% of patients completed 3-month follow-up. The mean age was 45 years (16 to 93) and 60% were female. The most common fractures were fibular (39%) and most injuries were caused by falls (75%). 99 % of these fractures were unilateral. Most fractures did not require surgical repair (93%), and 82% of patients were immobilized by cast or splint for an average of 42 ±32 days. Overall, 7 patients had symptomatic, objectively confirmed VTE (2 proximal DVT, 3 calf DVT, 2 PE) with no fatal PE – an incidence of 0.6 % (95% CI 0.2 to 1.2).

Conclusion: Symptomatic VTE is an infrequent complication after these fractures without thromboprophylaxis. Therefore routine thromboprophylaxis is neither warranted, nor likely to be cost-effective in these patients. This study also highlights the significant discrepancy between clinical endpoint studies and studies using venography.

As the population ages, the prevalence of degenerative spinal conditions is estimated to increase. With soaring healthcare costs, we must be vigilant in our accountability for proper resource allocation to ensure universal access. Significant recent increases in lumbar fusion rates have been observed in the US. Less is known regarding the Canadian experience. Our objective was to evaluate recent trends in lumbar fusion and determine how surgeon factors influence reoperation for spinal stenosis (SS) surgery.

Longitudinal follow-up study of lumbar surgical procedures for SS using administrative databases. Data was gathered on patient-hospital encounters from April 1, 1995 to December 31, 2001. We analyzed trends in spinal fusion. Index procedures (decompressions or fusions) and surgeon variables, such as specialty (orthopaedics, neurosurgery) and volume (above or below thirty cases/year), were selected as predictors of patient reoperation for SS. Adjustments were made for age, gender, and comorbidity. Reoperation rates were evaluated at six weeks, one and two years and until maximal follow-up.

6128 patients were identified (4200 decompressions and 1928 fusions). Proportionally more fusions were performed over the study period when compared to decompressions (1:2.6 in 1995 versus 1:1.5 in 2001). Orthopaedic specialty and higher surgical volume were associated with increased proportion of fusions (p< 0.0001). Reoperation rate was higher for decompressions at two years (OR 1.4) but not at long-term follow-up to ten years. Surgeon specialty had no impact on reoperation rates. Lower surgical volume demonstrated a higher reoperation rate after adjusting for specialty (Hazard Ratio 1.28).

Rates of lumbar spinal fusion have been increasing in Ontario, but at a lesser rate compared with the US. There is wide variation in surgical procedures between surgeon specialty and volume. Surgeon specialty had little impact on reoperation rates. Better long-term survival was observed in spinal surgeons with volumes over thirty cases per year after adjusting for surgeon specialty. Due to increasing rates of spinal fusion, the benefit of improved long-term survival in SS surgery with higher volume surgeons requires more detailed analysis before policy recommendations can be made.