Wedged tibial components for total knee arthroplasty

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Arthroplasty

Background:

• Severe coronal knee deformity often involves tibial condyle erosion, complicating total knee arthroplasty (TKA).
• Bone loss necessitates bone grafting, cement, or prosthetic augmentation to address tibial deficits.
• Early TKA designs faced challenges in managing significant tibial bone defects.

Purpose of the Study:

• To evaluate the efficacy of tibial components with integral polyethylene wedges in TKA for varus deformity.
• To assess the impact of these wedged components on component fixation and postoperative alignment.
• To compare outcomes of wedged components versus standard components in patients with tibial bone deficits.

Main Methods:

• Retrospective comparison of 26 patients with varus deformity treated with wedged components against 29 historic control subjects.
• Median follow-up of 8 years.
• Radiographic analysis for component loosening and cement fracture.

Main Results:

• No wedged components loosened, compared to loosening in five control subjects (P = .01).
• Three control subjects exhibited fractured cement triangles on radiographs.
• Postoperative alignment did not significantly improve with the use of wedged components.

Conclusions:

• Tibial components with integral wedges provide improved fixation in TKA for varus deformity.
• Enhanced fixation achieved with wedged components is independent of postoperative alignment.
• Wedged components offer a reliable solution for managing tibial bone deficits in TKA.