RESUMO
High tibial osteotomy (HTO) is a widespread option to avoid or delay total knee arthroplasty (TKA). The present study aimed to assess the long-term survival rate and postoperative subjective knee function after isolated medial open wedge HTO in patients with symptomatic medial compartment knee osteoarthritis (OA) and varus malalignment.Sixty-nine patients (48.8 ± 6.7, 35-66 years; preoperative mechanical tibiofemoral angle [mTFA] -5.3 ± 3.4; -14.9-0.0° varus) treated with medial open wedge HTO using a TomoFix plate were included in this retrospective study, with a follow-up of at least 10 years (11.8 ± 1.0 years). The survival rate after HTO was calculated after 5 and 10 years. Subjective knee function was assessed using Hospital for Special Surgery (HSS), Oxford knee, Lequesne, and Lysholm scores.Thirty-three patients underwent conversion to TKA, on average, 7.0 ± 3.4 (1.3-13.7) years after HTO. Five- and ten-year survival rates were 84.1 and 60.9%, respectively. Patients without conversion to TKA showed a Lysholm score of 64.5 (35-92), Lequesne score of 7 (1-13), HSS score of 71 (56-86), and Oxford knee score of 38.5 (25-44) at the last follow-up (more than 10 years). Significantly higher scores were registered at the last follow-up compared to the preoperative state regarding the Lysholm score (preoperative: 43.5 [12-95]; follow-up: 64.5 [35-92]; p < 0.001). The HSS score (preoperative: 69.5 [43-93]; follow-up: 71 [56-86]; p = 0.6941) showed no statistically significant change during the 10-year follow-up period. The Lequesne score was significantly lower than the preoperative score (preoperative: 11.5 [0.5-22]; follow-up: 7 [1-13]; p < 0.001), indicating a lower handicap.The majority of patients with a valgus medial compartmental knee OA treated with HTO with fixation using the TomoFix plate can expect no conversion to TKA for more than 10 years. Furthermore, patients without conversion to TKA after 10 years still had a significantly higher subjective knee function than preoperatively. Further research is needed to identify risk factors for conversion to TKA. This helps to guide surgeons in selecting patients who will benefit most from HTO.
RESUMO
BACKGROUND: The subjective health related quality of life in patients with degenerative joint diseases is an important variable to evaluate the treatment outcome. In this study, mid-term results of open wedge HTO were analysed and compared to the subjective quality of life (SF 36) of the general population. Furthermore, the relationships of preoperative assessed subscales of the health-related quality of life (SF 36) and the conversion to knee arthroplasty were analysed. METHODS: The cohort consisted of 120 patients who were prospectively followed-up after open wedge HTO. At five follow-up points of time, patients were examined and asked about their subjective, health-related quality of life using the SF 36 score. RESULTS: 104 patients were included and evaluated until the last follow-up (mean: 81.2 ± 11.3 months after open wedge HTO; follow-up rate: 86.7%). Six years after open wedge HTO, similar values in several psychologic subscales of the SF 36 (BP, GH, V, MH) and the mental health component summary score (MCS) compared to the general population were found. The physical health component summary score (PCS) showed a significant improvement relative to the preoperative values. Nine out of 104 patients (8.7%) received a knee arthroplasty (50.1 ± 25.0 months). Low preoperative values of the subscales "physical functioning" (PF) and "bodily pain" (BP) were identified as risk factors in terms of conversion to a total knee arthroplasty. CONCLUSIONS: Patients with medial unicompartimental knee osteoarthrosis treated with open wedge HTO showed very good results. The health-related quality of life was nearly as high as in the general population. Patients with preoperative low physical function and high pain values have a higher risk to have a conversion to knee arthroplasty. Surgeons should be aware of these factors if an open wedge HTO is considered.
