Sex does not clinically influence the functional outcome of total knee arthroplasty but females have a lower rate of satisfaction with pain relief

N D Clement,D J Deehan,D Weir,J Holland

doi:10.1186/s43019-020-00048-1

Abstract

BackgroundThe aims were to assess whether sex had a clinically significant independent influence on the outcome of total knee arthroplasty (TKA) according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Short Form (SF-) 12 scores and patient satisfaction at 1 year.MethodsA retrospective cohort of 3510 primary TKA were identified. Patient demographics, comorbidities, WOMAC and SF-12 scores were collected preoperatively and 1 year postoperatively. Patient satisfaction were assessed at 1 year.ResultsThere were 1584 males and 1926 females. The preoperative WOMAC and SF-12 scores were significantly (p < 0.001) worse in females but were not greater than the minimal clinically important difference (MCID). When adjustments had been made for confounding differences, females showed a significantly greater improvement in their function (1.5 points, p = 0.03) and total (1.5 points, p = 0.03) WOMAC scores compared to males, but these were not greater than the MCID. When adjustments had been made for confounding differences, females were less likely to be satisfied with their pain relief (p = 0.03) relative to males.ConclusionSex does not clinically influence the knee specific outcome (WOMAC) or overall generic (SF-12) health 1 year after TKA. However, satisfaction with pain relief after TKA was significantly less likely in female patients.Level of evidence IIPrognostic retrospective cohort study.

Highlights

A higher prevalence of osteoarthritis exists in females relative to males, which is reflected in a greater proportion of females undergoing total knee arthroplasty (TKA) per year [1]
The primary aim of this study was to assess whether sex had a clinically significant independent influence on the outcome of TKA according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score
Female patients had a significantly higher body mass index (BMI) (p < 0.001) and were less likely to suffer from heart disease (p < 0.001), diabetes (p = 0.04) and cancer (p = 0.03) but more likely to suffer from lung disease (p = 0.010), gastric ulceration (p < 0.001), anaemia (p = 0.001), back pain (p < 0.001) and depression (p < 0.001) when compared to male patients (Table 1)

Summary

Introduction

A higher prevalence of osteoarthritis exists in females relative to males, which is reflected in a greater proportion of females undergoing total knee arthroplasty (TKA) per year [1]. Conflicting evidence exists as to the influence of sex on the outcome of TKA, with some authors reporting worse postoperative functional outcomes and lower satisfaction rates in females [5,6,7], whereas others report no difference [8, 9]. Female patients generally report worse preoperative pain and functional scores relative to males prior to their TKA. This may be related to females choosing to delay joint replacement and subsequent progression and worsening of their symptoms [10]. The aims were to assess whether sex had a clinically significant independent influence on the outcome of total knee arthroplasty (TKA) according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Short Form (SF-) 12 scores and patient satisfaction at 1 year

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Results

Discussion

Conclusion