To investigate the short-term clinical efficacy of high tibial osteotomy (HTO) combined with arthroscopy versus arthroscopy alone in the treatment of senile degenerative knee osteoarthritis (KOA) (improvement of sport and pain).

A total of 41 elderly patients (42 knees) with Kellgren-Lawrence (K-L) stage Ⅲ KOA in Beijing Puren Hospital from July 2017 to May 2019 were retrospectively analyzed. The inclusion criteria: patients met the diagnostic criteria of knee osteoarthritis and were confirmed as medial KOA by preoperative MRI with intact ligament function; healthy elderly patients over 60 years; the range of motion of knee above 100 °; the patients could be followed up continuously. The exclusion criteria: the patients who did not meet the diagnostic criteria for KOA; age under 60 years; severe patellofemoral arthritis or osteoporosis or lateral compartment osteoarthritis; lateral meniscectomy; not degenerative osteoarthritic; unstable knees; preoperative range of motion of knee under 100° or flexion contracture >25°; the patients could not tolerate anesthesia or surgery; the patients lost follow-up, or were not healthy. The enrolled patients were divided into two groups according to their willingness for treatment methods: the HTO combined with arthroscopy group(the combined treatment group) and the arthroscopy group. The baseline characteristics of the patients were recorded. Knee injury & osteoarthritis score (KOOS), range of motion (ROM) and metabolic equivalents (METs) were compared between the two groups before the operation and 12 months after the operation. The proximal medial tibial angle (MPTA) and femorotibial angle (FTA) of the combined treatment group were compared before the operation, two weeks and 12 months after the operation, and the loss of correction angle was recorded. Paired and independent sample t test, rank sum test and chi square test were used for statistical analysis. Kaplan-Meier curve analysis was performed.

The postoperative KOOS (pain, symptoms, activities of daily living, sports and recreation, quality of life) scores of patients in the two groups were improved compared with those before operation (Z=-4.036, t=-12.116, t=-9.392, Z=-3.897, t=-3.623, Z=-4.041, t=-36.102, t=-12.116, Z=-4.133, t=-56.950, all P<0.001). The mobility and METs of the HTO group were significantly improved compared with those before operation (t=-13.436, Z=-4.116, both P<0.001), but there was no improvement in the arthroscopy group. The postoperative KOOS score, range of motion, and metabolic equivalent in the HTO group were significantly improved compared with those in the arthroscopy group (Z=-5.793, t=-27.755, t=-24.366, Z=-5.629, t=-43.958, t=-11.730, Z=-6.099, all P<0.001). Compared with the preoperative group, the FTA and MPTA of the HTO group had significantly improved at two weeks and 12 months after surgery. The postoperative combination group were able to survive without pain or with mild pain for a short-and medium-term time (time>12 months), which was better than the arthroscopy group, and the survival time difference between the two groups was statistically significant (χ²=42.290, P<0.001).

HTO combined with arthroscopy has good short-term clinical efficacy (sport and pain relief) in the treatment of elderly patients with K-L Ⅲ KOA; the correction of deformed force lines could lead to pain relief and sport improvement.