Background
Angular deformities of the leg resulting from malunion of distal tibial fractures or physeal arrest in skeletally immature patients are usually associated with ankle and foot pain secondary to disturbed mechanics and joint overload and could inevitably lead − if uncorrected − to degenerative arthritis. This prospective, case series study aims to evaluate the functional and radiological outcomes of supramalleolar corrective osteotomies for treating symptomatic angular deformities of the tibia and to assess its role in preventing or postponing degenerative arthritis of the ankle joint.
Patients and methods
This study included 18 patients presented with symptomatic angular tibial deformities secondary to malunion of previous distal tibial fractures or post-traumatic physeal arrest. Twelve patients had varus deformities of the ankle, while six patients had valgus deformities. Partial fibulectomy proximal to the level of the planned osteotomy was initially done in all patients; varus deformities were corrected with medial opening-wedge osteotomy and bone grafting with or without tibial fixation, while valgus deformities were corrected with medial closing-wedge osteotomy fixed by plates and screws. The ankle–hindfoot scale of the American Orthopaedic Foot and Ankle Society was used for evaluating the functional results preoperatively and postoperatively.
Results
The mean age of the patients at presentation was 17.6±5.9 years (ranged from 10 to 44 years). All the osteotomies united in an average duration of 10±4.8 weeks (ranged from 7 to 15 weeks) with no reported surgery-related complications apart from delayed wound healing in two cases. The deformity was clinically improved in all the 18 patients, while the radiological parameters were satisfactory in 16 patients with statistically significant improvement (<0.001) in mean postoperative tibial articular surface, talar tilt, tibiocrural, and the malalignment angles in the last follow-up compared with the mean preoperative values while two cases showed incomplete correction with residual deformity in the last follow-up. The mean (American Orthopaedic Foot and Ankle Society) ankle–hindfoot score was markedly improved from 43.8±7.5 preoperatively to 75.6±9.4 in the last follow-up indicating a statistically significant improvement (<0.001). No progressive joint narrowing was detected in any of the studied cases throughout the follow-up period that extended for with a mean duration of 5.5±2.8 years.
Conclusion
Supramalleolar osteotomy is an effective procedure for treating symptomatic angular deformities of the tibia. Supramalleolar osteotomies − not only − correct the deformity and improve the functional outcome, but also represent a joint-preserving surgery protecting the articular cartilage through correcting the mechanics and equally redistributing the joint loads thus preventing progressive degenerative arthritis.