Thresholds for Oxford Knee Score after total knee replacement surgery:a novel approach to post-operative evaluation

Abstract Background In a prospective cohort study, we wanted to detect thresholds distinguishing between patients with a satisfactory and an unsatisfactory outcome after total knee replacement (TKR) based on Patient-Reported Outcome Measures (PROMs), namely the Oxford Knee Score (OKS), using patient satisfaction and patient-perceived function as global transition items. Methods Seventy-three TKR patients completed the OKS questionnaire before surgery and were invited to complete the same questionnaire again 6 (4 to 9) months after surgery. Correlations between outcome measures and anchors were calculated using Pearson’s correlation coefficient. Thresholds were established by receiver operating characteristics (ROC) analysis, using multiple anchor-based approaches. Results Patients showed a mean increase of 16.5 (SD 9.5) in OKS following TKR. Significant positive correlations were found between outcome measures and anchors. Six different thresholds were determined for outcome measures coupled with satisfaction, patient-perceived function and a combination thereof using a cut-off of 50 and 70. Conclusions This study has established a set of clinically meaningful thresholds for Oxford Knee scores that may help to detect TKR patients who might be in need of post-operative evaluation

Thromboprophylaxis only during hospitalisation in fast-track hip and knee arthroplasty, a prospective cohort study

OBJECTIVES: International guidelines recommend thrombosis prophylaxis after total hip arthroplasty (THA) and total knee arthroplasty (TKA) for up to 35 days. However, previous studies often have hospital stays (length of stay; LOS) of 8–12 days and not considering early mobilisation, which may reduce incidence of venous thromboembolic events (VTE). We investigated the incidence of any symptomatic thromboembolic events (TEEs) with only in-hospital prophylaxis if LOS ≤5 days after fast-track THA and TKA. DESIGN: A prospective descriptive multicentre cohort study in fast-track THA and TKA from February 2010 to December 2011, with complete 90-day follow-up through the Danish National Patient Registry and patient files. SETTING: 6 Danish high-volume centres with a similar standardised fast-track setup, including spinal anaesthesia, opioid-sparing analgesia, early mobilisation, functional discharge criteria and discharge to own home. PARTICIPANTS: 4924 consecutive unselected unilateral primary THA and TKAs in patients ≥18 years with no preoperative use of continuous ‘potent’ anticoagulative therapy (vitamin K antagonists). EXPOSURE: Prophylaxis with low-molecular-weight heparin or factor Xa-inhibitors only during hospitalisation when LOS ≤5 days. OUTCOMES: Incidence of symptomatic TEE-related, VTE-related and VTE-related mortality ≤90 days postoperatively. RESULTS: LOS ≤5 days and thromboprophylaxis only during hospitalisation occurred in 4659 procedures (94.6% of total). Median LOS and prophylaxis duration was 2 days (IQR 2–3) with 0.84% (95% CI 0.62% to 1.15%) TEE and 0.41% (0.26% to 0.64%) VTE during 90-day follow-up. VTE consisted of five pulmonary embolisms (0.11% (0.05% to 0.25%)) and 14 deep venous thrombosis (0.30% (0.18% to 0.50%)). There were four (0.09% (0.04% to 0.23%)) surgery-related deaths, of which 1 (0.02% (0.00% to 0.12%)) was due to pulmonary embolism, and 6 (0.13% (0.06% to 0.28%)) deaths of unknown causes after discharge. CONCLUSIONS: The low incidence of TEE and VTE suggests that in-hospital prophylaxis only, is safe in fast-track THA and TKA patients with LOS of ≤5 days. Guidelines on thromboprophylaxis may need reconsideration in fast-track elective surgery. TRIAL REGISTRATION: ClinicalTrials.gov: NCT0155772