Variability of indication criteria in knee and hip replacement: an observational study

BACKGROUND. Total knee (TKR) and hip (THR) replacement (arthroplasty) are effective surgical procedures that relieve pain, improve patients' quality of life and increase functional capacity. Studies on variations in medical practice usually place the indications for performing these procedures to be highly variable, because surgeons appear to follow different criteria when recommending surgery in patients with different severity levels. We therefore proposed a study to evaluate inter-hospital variability in arthroplasty indication. METHODS. The pre-surgical condition of 1603 patients included was compared by their personal characteristics, clinical situation and self-perceived health status. Patients were asked to complete two health-related quality of life questionnaires: the generic SF-12 (Short Form) and the specific WOMAC (Western Ontario and Mcmaster Universities) scale. The type of patient undergoing primary arthroplasty was similar in the 15 different hospitals evaluated.The variability in baseline WOMAC score between hospitals in THR and TKR indication was described by range, mean and standard deviation (SD), mean and standard deviation weighted by the number of procedures at each hospital, high/low ratio or extremal quotient (EQ5-95), variation coefficient (CV5-95) and weighted variation coefficient (WCV5-95) for 5-95 percentile range. The variability in subjective and objective signs was evaluated using median, range and WCV5-95. The appropriateness of the procedures performed was calculated using a specific threshold proposed by Quintana et al for assessing pain and functional capacity. RESULTS. The variability expressed as WCV5-95 was very low, between 0.05 and 0.11 for all three dimensions on WOMAC scale for both types of procedure in all participating hospitals. The variability in the physical and mental SF-12 components was very low for both types of procedure (0.08 and 0.07 for hip and 0.03 and 0.07 for knee surgery patients). However, a moderate-high variability was detected in subjective-objective signs. Among all the surgeries performed, approximately a quarter of them could be considered to be inappropriate. CONCLUSIONS. A greater inter-hospital variability was observed for objective than for subjective signs for both procedures, suggesting that the differences in clinical criteria followed by surgeons when indicating arthroplasty are the main responsible factors for the variation in surgery rates.

Popliteal pseudoaneurysm after unicompartmental knee replacement: a case report.

Popliteal pseudoaneurysm is a rare but important complication of knee arthroplasties. To our knowledge, this complication has not been reported previously in the literature after unicompartmental knee arthroplasty. Apart from intraoperatively caused arterial injuries, obese patients and other previous cardiovascular diseases may be potential factors of risks for pseudoaneurysm in knee surgeries. As it is an uncommon complication and it has inconspicuous symptoms, both diagnosis and treatment can be delayed. This means that a high level of suspicion is necessary to prevent serious complications derived from pseudoaneurysms. LEVEL OF EVIDENCE Level IV.

Transcultural adaptation and validation of the "Hip and Knee" questionnaire into Spanish.

BACKGROUND The purpose of the present study is to translate and validate the "Hip and Knee Outcomes Questionnaire", developed in English, into Spanish. The 'Hip and Knee Outcomes Questionnaire is a questionnaire planned to evaluate the impact in quality of life of any problem related to the human musculoskeletal system. 10 scientific associations developed it. METHODS The questionnaire underwent a validated translation/retro-translation process. Patients undergoing primary knee arthroplasty, before and six months postoperative, tested the final version in Spanish. Psychometric properties of feasibility, reliability, validity and sensitivity to change were assessed. Convergent validity with SF-36 and WOMAC questionnaires was evaluated. RESULTS 316 patients were included. Feasibility: a high number of missing items in questions 3, 4 and 5 were observed. The number of patients with a missing item was 171 (51.35%) in the preoperative visit and 139 (44.0%) at the postoperative. Internal validity: revision of coefficients in the item-rest correlation recommended removing question 6 during the preoperative visit (coefficient <0.20). Convergent validity: coefficients of correlation with WOMAC and SF-36 scales confirm the questionnaire's validity. Sensitivity to change: statistically significant differences were found between the mean scores of the first visit compared to the postoperative. CONCLUSION The proposed translation to Spanish of the 'Hip and Knee Questionnaire' is found to be reliable, valid and sensible to changes produced at the clinical practice of patients undergoing primary knee arthroplasty. However, some changes at the completion instructions are recommended. LEVEL OF EVIDENCE Level I. Prognostic study.