Complications of Tibial Tubercle Surgery

OBJECTIVES: Tibial tubercle osteotomy (TTO) is a common procedure that is frequently used in the treatment of recurrent patellar instability and/or patellar chondrosis. Medialization of the tubercle decreases the lateral quadriceps vector of the patella resulting in load shifting away from the lateral patella. Distalization of the tubercle decreases patella height and allows for earlier containment of the patella in the bony walls of the trochlear groove. Anteriorization has been shown to be an effective treatment to unload the inferior lateral patella when chondrosis of the patella is present in this region. Current estimates of this procedure’s complication rates range from 0% to 11%. The purpose of this study was to review the complication rate following TTO performed within an academic sports medicine practice. The hypothesis was that complication rate for TTO is greater than 10% and that the rate of complications with distalization exceeds that of medialization alone. METHODS: All patients between May 2009 and May 2015 who underwent a TTO were retrospectively identified. Those with at least 6 months of follow up or a complication within the first 3 months were included for data analysis. Complications were identified and labeled as either major or minor. Major complications were defined as fracture of the tibia, deep infection requiring surgical debridement, nonunion requiring revision fixation, delayed union requiring bone graft, bone stimulation, or screw exchange, arthrofibrosis requiring manipulation under sedation and/or open lysis of adhesions, loss of fixation of the tubercle fragment, and deep vein thrombosis (DVT) whereas minor complications were defined as removal of symptomatic hardware, superficial wound infection, disturbance of cutaneous sensation, and delay in wound healing not requiring surgery. RESULTS: During the study period, 126 TTO were performed. Representing the study cohort are 111 patients, who have at least 6 months of follow up or a complication within 3 months. The mean follow up was 23 months. There were 62 of 126 (49.2%) TTO performed for patellofemoral instability and 23 of 126 (18.2%) for patellofemoral chondral damage. Thirty-eight osteotomies were performed for both instability and cartilage damage (30.2%). Two osteotomies were performed solely for patella alta and one TTO was performed for unspecified reason (2.4%). Of the complications, 28 came following distalization of the tubercle and 4 of these complications represent subsequent tibia fracture. Overall, the complication rate was 28.7 percent; major (17.1%) and minor (11.6%) complication rates are shown in Table 1. Subgroup analysis shows a complication rate of 54% for tubercles that were distalized versus 46% for medialization alone. CONCLUSION: The rate of total complication for TTO was 28.7%, this is greater than the estimated rate of complication in the current literature. Further, the rate of complications when the tibial tubercle was distalized was greater than when medialized alone suggesting that special considerations be made with this cohort. This high rate of complication is accompanied by a high rate of arthrofibrosis when compared to current literature suggesting the need for preoperative discussion as well as a detailed plan for postoperative rehabilitation to improve motion in patients and decrease the need for subsequent intervention. This study’s findings may redirect patient and physician discussions regarding risks of tibial tubercle osteotomies.