Anders Troelsen

What Factors Predict Failure 4 to 12 Years After Periacetabular Osteotomy

BackgroundThe goal of periacetabular osteotomy (PAO) is to delay or prevent osteoarthritic development in dysplastic hips. However, it is unclear whether the surgical goals are achieved and if so in which patients. This information is essential to select appropriate patients for a durable PAO that achieves its goals.Questions/purposesWe therefore (1) determined hip survival rates; (2) determined how many preserved hips were functionally unsuccessful after PAO; and (3) identified demographic, clinical, and radiographic factors predicting failure after PAO.MethodsWe retrospectively reviewed 316 patients (401 hips) who had PAO between December 1998 and May 2007. We evaluated radiographic parameters of dysplasia and osteoarthritis and obtained WOMAC scores. Through inquiry to the National Registry of Patients, we identified conversions to THA. Risk factors for conversion to THA were assessed. Minimum followup was 4xa0years (mean, 8xa0years; range, 4–12xa0years).ResultsThe overall Kaplan-Meier hip survival rate was 74.8% at 12.4xa0years. A WOMAC pain score of 10 or more, suggesting clinical failure, was observed in 13% of preserved hips at last followup. Higher age, preoperative Tönnis grade of 2, incongruent hip, postoperative joint space width of 3xa0mm or less, and postoperative center-edge angle of less than 30° or more than 40° predicted conversion to THA.ConclusionsPAO preserved three of four hips with most functioning well at 4- to 12-year followup. When planning surgery, surgeons should attempt to achieve hip congruence and a center-edge angle of between 30° to 40° to improve the durability of PAO.Level of Evidence Level II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

No effect of fibrin sealant on drain output or functional recovery following simultaneous bilateral total knee arthroplasty: a randomized, double-blind, placebo-controlled study.

Background and purpose Blood loss after total knee arthroplasty (TKA) may lead to anemia, blood transfusions, and increased total costs. Also, bleeding into the periarticular tissue may cause swelling and a reduction in quadriceps strength, thus impairing early functional recovery. In this randomized, double-blind, placebo-controlled study, we analyzed the possible effect of fibrin sealant on blood loss and early functional recovery in a fast-track setting. Methods 24 consecutive patients undergoing bilateral simultaneous TKA were included. 10 mL of fibrin sealant (Evicel) was sprayed onto one knee whereas the contralateral knee had saline. Drain output, the primary outcome, was measured from knee drains removed exactly 24 h after surgery. Secondary outcomes (knee swelling, pain, strength of knee extension, and range of movement (ROM)) were evaluated up to 21 days after surgery. Results The drain output in knees treated with fibrin sealant and placebo was similar (582 mL and 576 mL, respectively). Likewise, no statistically significant differences were found between groups regarding swelling, pain, strength of knee extension, and ROM. Interpretation Fibrin sealant as a local hemostatic in TKA showed no benefit in reducing drain output or in facilitating early functional recovery when used with a tourniquet, tranexamic acid, and a femoral bone plug.

Minimal important change values for the Oxford Knee Score and the Forgotten Joint Score at 1 year after total knee replacement

Background and purpose — Interpreting changes in Oxford Knee Score (OKS) and Forgotten Joint Score (FJS) following total knee replacement (TKR) is challenged by the lack of methodologically rigorous methods to estimate minimal important change (MIC) values. We determined MIC values by predictive modeling for the OKS and FJS in patients undergoing primary TKR. Patients and methods — We conducted a prospective cohort study in patients undergoing TKR between January 2015 and July 2016. OKS and FJS were completed preoperatively and at 1 year postoperatively, accompanied by a 7-point anchor question ranging from “better, an important improvement” to “worse, an important worsening.” MIC improvement values were defined with the predictive modeling approach based on logistic regression, with patients’ decisions on important improvement as dependent variable and change in OKS/FJS as independent variable. Furthermore, the MICs were adjusted for high proportions of improved patients. Results — 333/496 (67.1%) patients with a median age of 69 years (61% female) had complete data for OKS, FJS, and anchor questions at 1 year postoperatively. 85% were importantly improved. Spearman’s correlations between the anchor and the change score were 0.56 for OKS, and 0.61 for FJS. Adjusted predictive MIC values (95% CI) for improvement were 8 (6–9) for OKS and 14 (10–18) for FJS. Interpretation — The MIC value of 8 for OKS and 14 for FJS corresponds to minimal improvements that the average patient finds important and aids in our understanding of whether improvements after TKR are clinically relevant.