Effect of medial opening wedge distal tibial tuberosity osteotomy on possible neuropathic pain in patients with osteoarthritis of the knee.

BACKGROUND:There is a paucity of literature regarding the changes and features of neuropathic pain (NP) in knee osteoarthritis (OA) following medial opening wedge distal tibial tuberosity osteotomy (OWDTO). This study aimed to investigate the effect of OWDTO on NP in knee OA; we hypothesized that OWDTO improves knee symptoms and functions and also meets patient satisfaction in those with knee OA with possible NP or without NP. METHODS:Fifty-two consecutive patients who underwent OWDTO were categorized into the unlikely NP and possible NP groups using the painDETECT questionnaire. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) score and the Knee Society Score 2011 (KSS 2011) were compared between the groups preoperatively and at the 1-year follow-up. RESULTS:The number of patients having possible NP significantly decreased from 12 (23.1%) preoperatively to one (1.9%) postoperatively (p < 0.001). The patient with postoperative possible NP also had possible NP preoperatively. All preoperative sub-scores of WOMAC were significantly higher in the possible NP group than in the unlikely NP group (p = 0.018, 0.013, 0.004, and 0.005, respectively); however, the postoperative scores did not differ between the two groups. Regarding the KSS 2011, the preoperative scores for symptom and functional activities were significantly lower in the possible NP group than in the unlikely NP group (p = 0.031 and 0.024, respectively). CONCLUSIONS:OWDTO is an effective surgery for patients with possible NP; it improves symptoms and knee function as well as meets patient satisfaction. LEVEL OF EVIDENCE:Level IV, therapeutic case series.