Total Knee Arthroplasty due to Knee Osteoarthritis: Risk Factors for Persistent Postsurgical Pain

Abstract

Objective: The aim of this study was to identify whether different patient characteristics and clinical factors can be risk factors in patients with persistent postsurgical pain (PPSP) after total knee arthroplasty (TKA).

Methods: Patients who underwent TKA due to knee osteoarthritis were divided into two groups: those who experienced no or mild PPSP (Numerical Rating Scale [NRS] ≤ 3) (group 1, n = 91) and those who experienced moderate to severe PPSP (NRS > 3) (group 2, n = 183). Information on the characteristics of patients, comorbid diseases and pre-surgical NRS scores were obtained retrospectively from hospital charts. The follow-up time; pre-surgical and last control time walking distance; and ratings on the NRS, Pain DETECT Questionnaire (PDQ) and patient satisfaction scales were recorded from the standard questionnaire presented to patients during the telephone interview.

Results: The mean follow-up time was 22.8 ± 12.3 months. The rate of moderate to severe PPSP among patients amounted to 66.7% after TKA. No neuropathic pain was found in Group 1. In Group 2, 22.9% of patients experienced neuropathic pain, the results for 18% of patients were uncertain, and 59% of patients did not experience neuropathic pain. Group 2 had worse scores on the patient satisfaction scale following the last control time compared with Group 1. Being widowed, having a low education level, being a housewife, having employment that requires physical effort, pre-surgical pain intensity at rest and pre-surgical restricted walking distance are risk factors for Group 2.

Conclusions: PPSP and the neuropathic component in PPSP after TKA are not underestimated for pain management and patient satisfaction. Subgroups of patients, particularly widowers, having a primary school education level or under, housewives, people with jobs that require physical effort, individuals with intense pre-surgical pain during rest and those suffering from pre-surgical restricted walking distance, are at higher risk of developing PPSP following TKA.

Keywords: Neuropathic pain; Persistent postsurgical pain; Risk factor; Total knee arthroplasty.