Similar outcome for total knee arthroplasty after previous high tibial osteotomy and for total knee arthroplasty as the first measure

Background and purpose - Patients having a total knee arthroplasty (TKA) after a previous high tibial osteotomy (HTO) constitute a minor group among those undergoing primary TKA for knee osteoarthritis (OA). There have been few reports on whether such patients differ pre- and postoperatively from those who undergo TKA as the first measure. We evaluated patient characteristics, knee-related pain, function, quality of life, and general health before and 1 year after TKA surgery in these 2 groups of patients. Patients and methods - We included 119 HTOs that were operated on for knee OA in the Skåne region, Sweden, in the period1998-2007 and that had been converted to a TKA during 2009-2013 (the C group). We also included 5,013 primary TKAs performed for knee OA in the same region, during the same period, and in patients of the same age range (42-82 years) (the P group). The patients were evaluated with the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the EQ-VAS preoperatively and 1 year after the TKA surgery, when they were also asked about their satisfaction with the surgery. Case-mix variables available were Charnley category, American Society of Anesthesiologists (ASA) classification, sex, age, and body mass index (BMI). Results - Most of the HTOs were performed using open-wedge osteotomy with external fixation (81 of 119). Compared to the P group, the patients in the C group were more often men, were younger, and were healthier (according to the ASA classification). With respect to pre- and postoperative knee-related pain, function, quality of life, and general health, the 2 groups had similar mean values without any statistically significant differences. A similar proportion of patients in the 2 groups were satisfied with the surgery 1 year postoperatively (82% vs. 80%). Interpretation - Our findings indicate that HTO is a reasonable alternative for delaying TKA surgery in younger and/or physically active OA patients.