Long-term results of total knee arthroplasty for valgus knees: soft-tissue release technique and implant selection.

PURPOSE

To report long-term results of total knee arthroplasty (TKA) for valgus knees.

METHODS

34 women and 19 men aged 39 to 84 (mean, 74) years with valgus knees underwent primary TKA by a senior surgeon. Of the 78 knees, 43, 29, and 6 had type-I, type-II, and type-III valgus deformities, respectively. A preliminary lateral soft-tissue release was performed, and the tibia and femur were prepared. The tight lateral structures were released using the pie-crusting technique. In 92% of the knees, cruciate-retaining implants were used. In knees with severe deformity and medial collateral ligament insufficiency, the posterior cruciate ligament was sacrificed and constrained implants were used. The Hospital for Special Surgery (HSS) knee score was assessed, as were tibiofemoral alignment, range of motion, stability, and evidence of loosening or osteolysis.

RESULTS

Patients were followed up for 8 to 14 (mean, 10) years. All knees had a good patellar position and were clinically stable in both mediolateral and anteroposterior planes. No radiolucency was noted. The mean HSS knee score improved from 48 to 91 (p<0.001). The mean tibiofemoral alignment improved from valgus 20 to 5 degrees (p<0.001). The mean range of motion improved from 65 to 110 degrees (p<0.001). One patient developed a deep infection at year 4, and 2 had periprosthetic fractures at years 6 and 8.

CONCLUSION

Adequate lateral soft-tissue release is the key to successful TKAs in valgus knees. The choice of implant depends on the severity of the valgus deformity and the extent of soft-tissue release needed to obtain a stable, balanced flexion and extension gap, in order to achieve minimal constraint with maximum stability.