Poster 298: Complications Following Tibial Tubercle Osteotomy (TTO) at a Tertiary-Care Institution
Authors: Lehane DO Kevin M. , Wolfe Isabel , Buseck Alison , Strauss Eric J. , Jazrawi Laith M. , Golant Alexander 
Published: October 2024

Objectives:

Tibial tubercle osteotomy (TTO) can be used to treat patellar instability, patellar maltracking/compression, and patellofemoral cartilage damage. Reported complication rates following TTO range from 1% to 46%, with varied definitions of complication. The purpose of our study was to define the incidence of complications following TTO in a large cohort at a tertiary-care institution.

Methods:

Patients who underwent TTO between 2011 and 2023 were retrospectively identified. Patients who did not have at least 30 days of follow-up were excluded. Revision cases were excluded. Information about complications was obtained through review of the electronic medical record. Major complications included intraoperative fracture, postoperative fracture, loss of fixation, delayed union, non-union, pulmonary embolism (PE), patella tendon rupture, deep infection, painful hardware requiring removal, arthrofibrosis requiring reoperation, re-dislocation, reoperation for other indications, readmission, and revision. Minor complications included superficial infection, deep venous thrombosis (DVT), wound dehiscence, and postoperative neurapraxia. Chi-square tests were used for categorical variables, t tests for continuous variables.

Results:

Four hundred and seventy-six TTOs in 436 patients were included in the final cohort with a mean follow-up of 1.9 years. Patients were 68.5% female with average age 28.3 years.The overall complication rate was 27.5 percent. Major complications were recorded in 23.7% of patients, and minor complications in 8.4% of patients. Reoperation was required in 16.6% of patients at an average of 14 months after index procedure. The most common complications were painful hardware requiring removal (6.5%), superficial infection (5.7%), and arthrofibrosis requiring return to the operating room (5.0%). These and other complications are reported in Table 1 at 30 days, 90 days, 1 year, and final follow-up. Table 2 compares patient characteristics for those who had a major complication versus those who did not. Patients who had a major complication were older than those who did not (30.2 vs 27.7, p = .013). A higher proportion of patients who had a major complication had a previous ipsilateral surgery (57.5% vs. 36.6%, p < .001), had an indication of cartilage lesion/arthritis (71.7% vs. 60.6%, p = .034), and underwent a concomitant cartilage reconstruction/repair procedure (51.8% vs. 39.1%, p = .012). A lower proportion of patients who had a major complication had an indication of instability (56.6% vs. 67.2%, p = .043) and underwent a soft tissue reconstruction (46.4% vs. 60.1%, p = .012). There were no differences in the proportion of major complications by sex or American Society of Anesthesiologists score. Mean body mass index (BMI) did not differ significantly between patients who had a major complication and those who did not. Hardware removal was required in 6.5% of patients. More patients with headed as compared to headless screws required hardware removal (13.2% vs. 1.7%, p < .001). Arthrofibrosis requiring reoperation was observed in 5.7% of patients. A significantly higher proportion of patients who underwent a concomitant cartilage restoration/repair procedure had arthrofibrosis postoperatively (10.0% vs. 2.5%, p < 001). There was no difference in arthrofibrosis requiring reoperation by race, sex, age, BMI, smoking status, prior ipsilateral surgery, or other concomitant procedures.

Conclusions:

The complication rate following TTO was 27.5%, with painful hardware requiring removal (6.5%) as the most common complication, and a reoperation rate of 16.6% at a mean follow-up of 1.9 years. Major complications were observed in 23.7% of patients and were more common in older patients, patients with an indication of cartilage lesion/arthritis, patients who underwent a cartilage restoration/repair procedure, and patients with a previous ipsilateral surgery. Hardware removal was more common in patients with headed screws. Arthrofibrosis was more common in patients who underwent a concomitant cartilage restoration/repair procedure.