Summary

While BTB autograft is a commonly cited risk for anterior knee pain after ACL reconstruction compared to allograft, our study found that graft option did not significantly influence Kujala score or specific limitations related to anterior knee pain at 1 year after surgery.

Abstract

Background

Anterior cruciate ligament (ACL) reconstruction is one of the most commonly performed procedures in sports medicine, yet continued controversy exists with regard to optimal graft options. Patellar tendon (BTB) autograft has been associated with increased risk for anterior knee pain, however the severity of symptoms and limitation in function associated with this have not been quantified. Therefore our aim was to quantify the presence and severity of anterior knee symptoms, comparing knees undergoing BTB autograft vs BTB allograft, and identify risk factors for increased symptoms.

Methods

Patients who underwent ACL reconstruction with BTB autograft or BTB allograft by a single surgeon were prospectively enrolled and assessed at 1 year followup using the Kujala score, a validated measurement of patellofemoral symptoms. Kujala scores reported at 1 year were compared between groups using the Mann Whitney U test. Frequency of those reporting limitations in function specific to the anterior knee (pain with stairs, squatting, and prolonged sitting with the knees flexed), were reported and compared using two proportion z-test. Stepwise multiple regression analysis was performed to assess the role of risk factors identified at the time of surgery (graft type, age, BMI, and Outerbridge score of the patella and trochlea) on Kujala scores at 1 year followup.

Results

154 (86F,68M) were included in this study (mean age: 33.4+/-13.4). 91 patients underwent BTB autograft, while 63 patients underwent BTB allograft. At 1 year followup, patients with autograft BTB had a higher Kujala score (94.4+/-6.5 vs 90.1+/-11.5, p=0.039). 13.2% of autograft patients and 19.0% of allograft patients reported at least some difficulty with stairs at 1 year (p=0.324), whereas 16.4% and 25.4% reported some difficulty with squatting (p=0.175). 23.1% of patients with autograft and 17.4% of allograft patients reported pain with prolonged sitting (p=0.398). Stepwise multiple regression analysis demonstrated an independent negative relationship on Kujala score with older age at the time of surgery and increased Outerbridge score on the trochlea.

Conclusion

While BTB autograft is a commonly cited risk for anterior knee pain after ACL reconstruction, our study found that graft option did not significantly influence Kujala score or specific limitations related to anterior knee pain at 1 year after surgery. However, older age and greater severity of chondral defects on the trochlea at the time of surgery were found to increase the severity of anterior knee symptoms. Further study is needed to better understand the morbidity related to graft options and identify those at risk in patients undergoing ACL reconstruction.