The incidence of periprosthetic fractures after total knee arthroplasty (TKA) is increasing, and treatment is becoming more necessary. In periprosthetic tibial fractures, the stem of the tibial component largely occupies the medullary canal of the proximal tibia, which limits the selection of implants. The purpose of this study was to evaluate the effectiveness of the minimally invasive plate osteosynthesis (MIPO) technique with locking plates for periprosthetic tibial fractures after TKA.

Sixteen patients with periprosthetic tibial fracture after TKA were included. There were 6 type II and 10 type III fractures according to the Felix classification. Ten patients had fractures in the proximal metaphysis, and 6 in the diaphysis. MIPO using locking plates was performed on the medial side in 4 cases, the lateral side in 2 cases, and both in 10 cases. Radiographic results included time to union, alignment, and malunion. Clinical results included range of motion (ROM), functional activity data, Knee Society scores, and complications.

Fourteen of 16 fractures achieved union at 17.1 weeks (range, 14–24) postoperatively. There were 2 failures that required a secondary procedure. Except one for 1 case with varus malunion, all had acceptable alignment. Mean ROM at the final follow-up was 108.8° (range, 15–135°), and 15 patients recovered pre-injury knee joint activity. Mean knee and function scores were 88.9 (range, 77–100) and 83.3 (range, 60–100), respectively. Knees with fewer than 8 cortices giving purchase to screws in the proximal segment showed higher failure rates (P=0.025).

MIPO with locking plates can achieve satisfactory results for periprosthetic tibial fractures after TKA. Rigid fixation of the proximal segment may be necessary for successful outcome.

IV.