Intraoperative fractures are a reported complication during the course of primary total knee replacement. Major ligament disruptions can also occur. Clinical data are lacking to tell how much these incidents affect implantation quality and outcome.

A thorough knowledge of these occasional incidents helps proper decision making when confronted to such situations at surgery.

This report is based on a series of primary, posterostabilized total knee arthroplasties (posterostabilized, mobile bearing TKA with a third median condyle from Tornier Laboratory). We studied all possible mechanical complications that developed during the course of arthroplasty and analyzed their cause. We compared the functional results of patients presenting these complications to those of the total series and to data from the literature. The entire operative reports for the 1795 TKA performed during this study were available and evaluated. A clinical and radiological review was performed for 1624 patients at an average follow-up time of 36.8±34 (2–193) months.

At this last follow-up, the average International Knee Society (IKS) score was 91.2 (19–100) and the function score was 77.76 (0–100). One hundred and thirty-two patients were deceased (unrelated to TKA) at this last follow-up evaluation. A total of 69 mechanical complications were accounted for at the time of surgery (3.8%): 40 definite fractures or fissures around the knee (2.2%), 29 tendon or ligament disruptions or attenuations (1.6%). The risk of tibial cracks was statistically more significant, with the smaller sizes tibial trays (size 1) (p=0.019) or when an anterior tibial tuberosity elevation had been performed (p=0.02). Survival curve analysis (at an average seven and a half-years postoperative follow-up) showed that all prosthetic components were still present in 93.3% of cases in the series of patients with these peroperative complications, and in 93.8% of cases in the series of patients without these intraoperative complications; this survival rate amounted to 91.9% of cases at an average 16-years postoperative follow-up.

This large, homogeneous series of primary, posterostabilized TKA took on 3.8% of intraoperative bone or ligament complications. All these complications could be prevented by a rigorous surgical technique. The improvement of ancillary materials, the saws, and good knowledge of such complications by the surgeon are essential.

Level of evidence: Level IV. Therapeutic Study.