Poster 149: Donor Site Morbidity Following Anterior Cruciate Ligament Reconstruction Using Quadriceps Tendon Versus Bone-Patellar Tendon-Bone Autograft: Results at 2-Year Follow-up

Objectives: Bone-patellar tendon-bone (BTB) autograft has historically been regarded as the gold standard for anterior cruciate ligament reconstruction (ACLR). Despite widespread utilization of BTB autografts, multiple complications following BTB harvest have been reported, including anterior knee pain, difficulty kneeling, patellar tendon rupture, patella fracture, tendon contracture, and numbness. The quadriceps tendon (QT) autograft has been proposed as an alternative graft in young, high demand patients to achieve comparable clinical outcomes while avoiding complications associated with BTB autograft. Recently, a novel 10-question donor site morbidity (DSM) instrument was developed by Hacken et al that was used to evaluate DSM following BTB ACLR. However, to date, the instrument has not been used to evaluate DSM following QT harvest. Therefore, a retrospective evaluation of DSM following ACLR with QT versus BTB autograft was performed. Methods: All patients who underwent ACLR with QT autograft between January 2018 and February 2020 were identified in a single institution registry and matched to a control group of patients who underwent BTB autograft ACLR on the basis of age and sex. DSM was assessed using a 10-question DSM instrument and scores were compared to traditional patient reported outcome measures including the IKDC, Marx Activity Scale, and SANE scores. Post-operative complications including quadriceps tendon rupture, patella fractures, and graft failure were assessed via registry query. Multivariate analysis was conducted to investigate factors associated with DSM. Results: Thirty-two QT patients (15M,17F) with a mean age of 23.0 years (range 13-45) were compared to 61 BTB patients (32M,29F) with a mean age of 22.2 (range 13-45) who responded at a minimum 24- months after surgery. DSM scores were rated good or excellent in 26/31 QT patients(81%) versus 44/61 BTB patients(72%) (P=0.45). Significant differences were noted between graft types with respect to presence of numbness, with 37/61 BTB patients(61%) versus 10/32 QT patients(31%) reporting mild, moderate, or diminished sensation to light touch(P=0.02). Differences were also noted in kneeling pain, with 30/61 BTB patients(49%) versus 6/32 QT patients(19%) reporting either mild pain with kneeling or inability to kneel on hard surfaces (P=0.01). Finally, differences were reported in patient-reported presence of quadriceps wasting, with 20/32 QT patients(38%) reporting atrophy versus 15/61 BTB patients(25%) (P=0.01). However, no differences were noted in pain at donor site, size of numbness, difficulty with stairs or prolonged sitting, anterior knee pain, or incision cosmesis(P>0.05). Multivariate analysis demonstrated that graft type, sex, body mass index (BMI), operative age, and meniscus integrity were not associated with DSM scores(P>0.05). Correlations between PROMS and DSM showed correlations with IKDC, Marx, and SANE(P<0.01). There were no instances of quad tendon rupture, patella fracture, or ACL graft failure in either group. Conclusions: DSM following ACLR with QT and BTB autograft demonstrated good to excellent results in the majority of patients. Significantly more BTB patients experienced numbness at the harvest site and pain with kneeling compared to QT patients. However, more patients reported quadriceps atrophy following QT compared to BTB autograft. PROMS correlated with DSM scores, suggesting that these instruments may be impacted by DSM following ACLR.