Poster 335: Results Following Arthroscopic Scar Resection for Arthrofibrosis Post Anterior Cruciate Ligament Reconstruction
Authors: Claussen William , Bauman Scot , Shelbourne K. Donald , Benner Rodney 
Published: August 2024

Objectives: Arthrofibrosis following anterior cruciate ligament reconstruction (ACLR) is a complication resulting in loss or range of motion (ROM) and function. Classification and outcomes of treatment for arthrofibrosis vary as surgical approaches can be taken from the anterior and posterior aspects. The purpose of this study was to define categories of arthrofibrosis and report outcomes of arthroscopic anterior scar resection (SR) after an ACLR. Methods: Patients who had an arthroscopic anterior SR post ACLR enrolled into the study with the following exclusion criteria: SR not preceded by an ACLR and an ACLR on the opposite knee. The indication for surgery was a painful loss of motion due to a mechanical limitation of knee extension from anterior scarring. All patients participated in a standard rehabilitation protocol before and after surgery, aimed at maximizing knee extension first, followed by flexion and strength. Patients were classified, preoperatively and postoperatively, into 4 categories based on ROM compared to the opposite knee: category 1 = extension loss ≤10°/flexion loss of ≤5°; category 2 = extension loss ≤10°/flexion loss >5°; category 3 = extension loss >10°/flexion loss ≤25°; category 4 = extension loss >10°/flexion loss >25°. Outcomes assessed preoperatively and postoperatively were side to side differences in ROM, rate of having normal ROM, and International Knee Documentation Committee (IKDC) scores. Maximum IKDC scores and ROM preoperatively, within the 6 months leading up to the SR, and postoperatively, within the first 3 years after the SR, were used for analysis. Normal extension and flexion were defined as being within 2° and 5°, respectively, of the other side. Results: For the 166 patients, mean age was 22.5 ± 7.7 years, 56% were male, and 58% had a subacute ACLR; all of which were not statistically significantly different between the preoperative categories. The distribution of categories before surgery (1: 58%, 2: 35%, 3: 3%, 4: 4%) improved after surgery (1: 83%, 2: 17%, 3: 0%, 4: 0%). Preoperatively, normal extension was achieved by 82% for category 1, 48% for category 2, and 0% for categories 3 and 4, p< 0.001. Postoperatively, normal extension was achieved by 96% of the total population, specifically, 97% for category 1, 95% for category 2, and 100% for categories 3 and 4, p=0.839. Postoperatively, normal flexion was achieved by 83% of the total population, specifically, 88% for category 1, 71% for category 2, and 100% for categories 3 and 4, p=0.026. The difference in postoperative extension was not different based on preoperative category (1: -0.22°, 2: 0.17°, 3: 0.40°, 4: 0.17°), p=0.284. Preoperative category 1 remained category 1 88% of the time and regressed to category 2 12% of the time. For category 2, 71% improved to category 1 and the rest remained category 2. For categories 3 and 4, all patients improved to category 1. Based on preoperative category, preoperative IKDC scores were different (1: 63, 2: 45, 3: 16, 4: 32), p<0.001; however, they were the same after surgery (1: 81, 2: 81, 3: 83, 4: 100), p=0.800. Conclusions: Ninety-six percent of patients achieved normal extension after an anterior SR and this was not affected by their preoperative arthrofibrosis category. Most patients were able to improve their category and IKDC scores after surgery, with those having more severe arthrofibrosis preoperatively resulting in better gains.