Periprosthetic supracondylar femoral fractures above total knee arthroplasty: comparison of the locking and non-locking plating methods.

PURPOSE: The purpose of this study was to compare the results and complications of periprosthetic supracondylar femoral fracture treatment using locking or non-locking plates.

METHODS: A locking compression plate was used in 14 patients, and a non-locking condylar buttress plate was used in 19 patients. There were no significant differences in the demographic data between the two groups. The primary healing rate and bone union time were compared. The Knee Society knee score and range of motion (ROM) were reviewed. The femorotibial angle and α and γ angles were measured using the Knee Society radiological evaluation method. The clinical and radiographic results, complications, and additional surgeries were compared between the two groups.

RESULTS: Thirteen of 14 locking plating patients and 11 of 19 non-locking plating patients healed without any additional surgeries. There were no differences in the average bone union time, knee score, or ROM between the two groups. The alignment and position of the implants were better without a loss in the reduction angle of >3° in the locking plating group compared with the non-locking plating group. Locking plate fixation reduced the incidence of overall complications, non-union, malunion, loss of reduction, and additional surgeries compared with non-locking plate fixation.

CONCLUSION: Fixation of periprosthetic supracondylar femoral fractures with a locking plate provided satisfactory results with a low risk of complications and additional surgeries compared with fixation with a non-locking plate.

LEVEL OF EVIDENCE: III.