Patients with severe Varus knees is not uncommon in developing countries, and TKA offers good results. The type of release required and need for constrained prosthesis needs to be defined. Purposes-1) Assess the adequacy of sequential medial soft tissue release in correcting the varus deformity in severe primary varus knees. 2) Assess the need for using constrained type of components. Patients and methods- 75 primary severe varus knees (≥20 degrees) in 52 patients presenting to us over 3 years were divided into 4 groups based on severity of varus. Group A (20-25 degree) had 31 patients, Group B (26-30 degrees) had 31 patients, Group C (31-35 degree) had 8 patients and Group D (36- 40 degree) had 5 patients. All patients were evaluated for the type of release required, the type of defect reconstruction needed and the need for constrained prosthesis intraoperatively. KSS scores were documented preoperatively and at final follow up.
Results: In group A, 27 patients (87%) required type 1 release and the rest 4 patients (13%) required type 2 release. In 19 patients defect was reconstructed by use of cement and in 4 patients cement +screw was used. 8 patients did not have defect after tibial cuts and balancing. In Group B, 12 patients (39%) required type 1 release and 19 patients (61%) required type 2 release. The defect was reconstructed with cement in 7 patients, with cement+screw in 14 patients, with bone graft in 8 patients and remaining 2 patients required augments. In group C, 2 patients (25%) needed type-3 release, 5 patients (62.5%) needed type 2 release and one patient (12.5%) needed type 1 release. The defect was reconstructed with augments in 2 patients, with bone graft in 5 patients and with cement+screw in one patient. Of the 5 patients in group D; 2 patients (40%) required type 4 release and 3 patients (60%) required type 3 release. All the 5 patients required augments for reconstruction of the tibial defect. None of our patients required constrained prosthesis.
Conclusion: Most patients with severe varus deformities can be managed successfully with sequential medial soft tissue release and defect reconstruction. With the increasing varus deformity, the defect reconstruction method increased from cement to cement+screw to bone graft and finally augments in severe cases. A CR/PS type of implants can be used in almost all cases and additional constraints and hinged implants are rarely required.