Knee reserved operation for knee osteoarthritis: proximal fibular osteotomy and high tibial osteotomy using absorbable balance spacer

Abstract

Purpose: A new combination of knee reserved operation, proximal fibular osteotomy with high tibial osteotomy (HTO) using an absorbable balance spacer implantation is proposed to treat medial compartment OA with serious varus deformities. Methods: Under epidural anesthesia, the patients were placed in the supine position with the lower limb tourniquet inflated. A 4 cm long lateral incision was made at the proximal third of the fibula. After exposing the fibula, a 2 cm long section of fibula was removed with oscillating saw. The fibula ends were sealed with bone wax. After the fibular osteotomy, a medial longitudinal incision then was made and the periosteum was striped. Retract the pesanserinu to expose the front and medial aspect of tibia. A guidewire was inserted beginning at the anteromedial tibia at the level of the superior border of the tibial tubercle, approximately 4-5 cm distal to the joint line. The guidewire direction was towards the tip of the fibular head. Partial osteotomy was performed with osteotomes. We originally designed a wedge-shape absorbable spacer with barbs on both surfaces aiming to prevent the spacer from escaping. The spacer was made of 70% PLGA (85/15) and 30% β-TCP. The spacer was then inserted into the osteotomy in order to achieve the planned degree of correction. The muscles, fascia and skin were sutured separately. Results: From Jul 2016 to Sep 2016, a total of 8 patients with an average of 61.8 years (range, 49 to 76) were enrolled into this study, including 7 females and 1 male. All patients were diagnosed with medial compartment KOA, all being grade 4 according to Kellgren-Lawrence Grading Scale. Anteroposterior and lateral weight-bearing radiographs were taken and the femorotibial angle (FTA) was measured. The Hospital for Special Surgery knee score (HSS) and the visual analog scale (VAS) score of the knee joint were evaluated preoperatively, 7thday postoperatively and at subsequent follow-ups. The FTA was 163.1° ± 1.7° measured on the preoperative anteoroposterior radiograph. The operations were performed uneventfully without intraoperative complications. The operative time was 81.3 ± 12.7 minutes. At 7th day postoperative follow-up, mean FTA was 175.5° ± 1.5°, which was significantly smaller than those measured preoperatively (P < 0.05). Mean VAS score and interquartile range were 1.5 and 1.0, significantly lower than the preoperative data (6.5 and 1.5, respectively; P < 0.001). The similar results were acquired in the 1-mouth postoperative follow-up for 3 patients and 2-mouth postoperative follow-up for 5 patients. Conclusions: The knee reserved operation, proximal fibular osteotomy and HTO using the originally designed wedge-shape absorbable spacer, was a minimally invasive, safe, simple, and effective procedure for the management of medial compartment OA of the knee joint.