Total Knee Arthroplasty with Intra-Articular Resection of Bone for Knee Arthritis Secondary to Malunion of a Tibial Shaft Fracture: A Radiological Evaluation of Correction of the Tibial Deformity

This retrospective study was aimed to evaluate the clinical outcome and the extent of correction of the tibial deformity by a radiological evaluation following total knee arthroplasty (TKA) combined with intra-articular bone resection, in patients with knee arthritis and ipsilateral malunited tibial fractures. Fifteen patients (15 knees) with severe arthritis of the knee and extra-articular malunion of the tibia were treated using TKA with intra-articular bone resection. The extra-articular deformities in the coronal plane were 10 tibia vara (mean 15°, range 9°-30°), 4 tibia valgum (mean 12°, range 6°-20°), and one double deformity in the tibial shaft. The follow-up duration was 84 months (24–240). At the last follow-up, the mean Knee Society knee and function scores had improved, respectively ( $p=0.001$ ). The mean arc of knee motion improved from 97° preoperatively to 118.3° at the last follow-up ( $p<0.001$ ). The mean mechanical axis improved from a preoperative 15.5° to 1.5° of varus ( $p=0.013$ ). Excluding the patient with a double tibial malunion, in the 10 patients with varus tibial angulations, the tibia vara had improved from 15° preoperatively to 2.6° ( $p=0.005$ ). There were no observed complications except for one with a postoperative deep infection. In conclusion, our results indicated that TKA with intra-articular resection of the bone is an effective procedure for the treatment of severe arthritis of the knee with extra-articular malunion of the tibia in the coronal plane (≤30° of varus; ≤20° of valgus).