To evaluate the clinical efficacy of total knee arthroplasty (TKA) in the treatment of primary osteoarthritis (OA) and osteoarthritis of Kashin-Beck disease (KBD).
This study enrolled 77 KBD patients (77 knees, KBD-TKA) and 75 OA patients (75 knees, OA-TKA) who underwent TKA from September 2008 to June 2018. Clinical assessments for each patient were performed pre-operatively and last follow-up. The efficacy measures included the visual analogue scale (VAS) pain score, range of motion (ROM), Hospital for Special Surgery (HSS) score, and short form 36 Health Survey (SF-36) as well as related influencing factors between the two groups.
All patients were followed up; the follow-up time of KBD-TKA was 14-132 months, with an average of 72.68 ± 37.55 months; OA-TKA was 15-120 months, with an average of 49.2 ± 28.91 months. There was no difference in pre-operative VAS score (7.29 vs. 7.24) and SF-36 (PCS) score (4.87 vs. 5.49) between KBD-TKA and OA-TKA (P > 0.05), while compared with OA, KBD-TKA had significantly worse pre-operative ROM (75.48° vs. 82.87°), HSS score (36.40 vs. 41.84), and SF-36 (MCS) score (26.28 vs. 28.73) (P < 0.05). At the final follow-up, there was no significant difference in VAS score (1.13 vs. 1.16), ROM (105.79 vs. 105.79), and HSS score (92.06 vs. 92.25) between KBD-TKA and OA-TKA (P > 0.05), while compared with OA, KBD-TKA had significantly worse SF-36 (PCS) score (36.90 vs. 42.00) and SF-36 (MCS) score (55.16 vs. 59.70) (P < 0.05). In a multivariate regression, controlling for multiple potential confounders, diagnosis of KBD was associated with poor quality of life after surgery, whereas pre-operative pain was specifically associated with post-operative pain. However, preoperative gender, age, BMI, and the angles of knee prosthesis (before and after surgery) were not associated with post-operative outcome.
Patients with KBD undergoing primary TKA have excellent outcomes, comparable with OA at the final follow-up, in spite of worse pre-operative ROM, HSS score, and SF-36(MCS) score. However, KBD patients are worse than OA in terms of general health. Pre-operative age, gender, BMI, and the angles of knee prosthesis were not the factors influencing the clinical efficacy of TKA. The diagnosis of KBD was an independent risk factor for poor quality of life after TKA. Pre-operative pain was a clinically important predictor of outcome.