KNEELING ABILITY AFTER KNEE ARTHROPLASTY

Abstract

Introduction and Aims: Kneeling is an important function of the knee joint but little information is available on ability to kneel after different types of knee arthroplasty. We aimed to assess patients’ kneeling ability pre- and post-operatively after uni-compartmental, patellofemoral and total knee arthroplasty (UKR, PFR, TKR) and to objectively examine: kneeling ability, factors that affect it and whether this ability differed from the patient’s perception.

Method: In 253 knee arthroplasty cases, we prospectively analysed the ability to kneel pre-operatively, and post-operatively at one and two years using the relevant section of the Oxford Knee Score questionnaire. One hundred and twenty-two post-operative patients (38 TKR, 53 UKR, 31 PFR) were then examined to assess their actual kneeling ability.

Results: Patients’ perception of their kneeling ability prior to surgery was poor in all three groups (mean score 0.7 out of 4) and improved in all groups after surgery (mean score at two years 1.46 out of 4). Perceived kneeling ability was best in UKR and worst in PFR (P< 0.001). Perceived kneeling ability improved most in the first year post-operatively, but continued to improve between one and two years although the final kneeling function was still not good. When examined, only 37% of patients thought they could kneel, whereas 81% were actually able to kneel (P< 0.001). Ability to kneel was significantly better than perceived ability for all prosthesis types (P< 0.001). Kneeling ability was better in men and associated with an increased range of movement (P< 0.001).

Conclusion: Kneeling ability is poor prior to knee arthroplasty and improves up to two years post-operatively, though it is still perceived to be poor, but can be improved with rehabilitation. UKR gave better kneeling ability than PFR or TKR. Patient-centred questionnaires do not accurately document kneeling ability after knee arthroplasty.