Outcomes of unilateral and bilateral total knee arthroplasty in 238,373 patients.

Background and purpose - There is no consensus about the outcome of simultaneous vs. staged bilateral total knee arthroplasty (TKA). We examined this issue by analyzing 238,373 patients. Patients and methods - Demographic, clinical, and outcome data were evaluated for TKA patients (unilateral: 206,771; simultaneous bilateral: 6,349; staged bilateral: 25,253) from the Canadian Hospital Morbidity Database for fiscal years 2006-2007 to 2012-2013. Outcomes were adjusted for age, sex, comorbidities, and hospital TKA volume. Results - Simultaneous bilateral TKA patients were younger than staged bilateral TKA patients (median 64 years vs. 66 years), were more likely to be male (41% vs. 39%), and had a lower frequency of having ≥1 comorbid condition (2.9% vs. 4.2%). They also had a higher frequency of blood transfusions (41% vs. 19%), a shorter median length of stay (6 days vs. 8 days), a higher frequency of transfer to a rehabilitation facility (46% vs. 9%), and a lower frequency of knee infection (0.5% vs. 0.9%) than staged bilateral TKA patients, but they had higher rate of cardiac complications within 90 days (2.0% vs. 1.7%). Simultaneous patients had higher in-hospital mortality compared to the second TKA in staged patients (0.16% vs. 0.06%), but they had similar rates of in-hospital mortality compared to unilateral patients (0.16% vs. 0.14%). The cumulative 3-year revision rate was highest in the unilateral group (2.3%), but it was similar in the staged and simultaneous bilateral groups (1.4%). Interpretation - We found important differences between the outcomes of simultaneous and staged bilateral TKA. Further clarification of outcomes would be best determined in an adequately powered randomized trial, which would remove the selection bias inherent in this retrospective study design.

Myxoid\round cell liposarcoma (MRCLS) revisited: an analysis of 418 primarily managed cases.

BACKGROUND: Objectives of this study were to evaluate oncologic outcomes and to provide guidelines for the management of primary myxoid (MLS) and round cell liposarcoma (RCLS). METHODS: A multicenter, retrospective study of 418 cases of MRCLS primarily managed by Canadian multidisciplinary sarcoma teams. RESULTS: Study included 418 cases (MLS: 311 patients and RCLS: 107; >5% round cell) with a median age of 45 years and a median follow-up of 5.2 years. Median tumor size was 10 cm, and 81% were deep and 90% were in lower limb. The majority of patients underwent surgical resection and radiotherapy, with a small percentage (6%) receiving chemotherapy. The overall 10-year local control rate was 93% with no differences between MLS and RCLS. Radiotherapy was significant in preventing local relapse and reducing tumor diameter (median=18%) and improving microscopic margin status, but did not impact survival. Radiotherapy and the margin status were independent predictors of local recurrence. The 5- and 10-year metastatic-free survivals were 84 and 77% respectively for MLS and 69 and 46% for RCLS. The initial site of metastasis was found in multiple locations (34%) and bone involvement was frequent (40%) with predilection for spine (79%). Round cell percent (>5%) and tumor diameter (>10 cm) correlated with increased risk for metastasis and death. CONCLUSIONS: MLS and RCLS showed different metastatic risk but equally good local control. Radiotherapy was effective in preventing local recurrence and should be delivered as neoadjuvant. New staging strategies are to be defined to account for the unusual metastatic pattern.