Risk Factors Associated With Poor Outcomes After Quadriceps Tendon Repair

Abstract

Background: Ruptures of the quadriceps tendon present most frequently in older adults and individuals with underlying medical conditions. Purpose: To examine the relationship between patient-specific factors and tear characteristics with outcomes after quadriceps tendon repair. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective review was conducted on all patients who underwent quadriceps tendon repair between January 1, 2016, and January 1, 2021, at a single institution. Patients <18 years and those with chronic quadriceps tendon tears (>6 weeks to surgery) were excluded. Information was collected regarding patient characteristics, presenting symptoms, tear characteristics, physical examination findings, and postoperative outcomes. Poor outcome was defined as a need for revision surgery, complications, postoperative range of motion of (ROM) <110° of knee flexion, and extensor lag of >5°. Results: A total of 191 patients met the inclusion criteria. Patients were aged 58.5 ± 13.2 years at the time of surgery, were predominantly men (90.6%), and had a mean body mass index (BMI) of 32.2 ± 6.3 kg/m2. Patients underwent repair with either suture anchors (15.2%) or transosseous tunnels (84.8%). Postoperatively, 18.5% of patients experienced knee flexion ROM of <110°, 11.3% experienced extensor lag of >5°, 8.5% had complications, and 3.2% underwent revision. Increasing age (odds ratio [OR], 1.03 [95% CI, 1.004-1.07]) and female sex (OR, 3.82 [95% CI, 1.25-11.28]) were significantly associated with postoperative knee flexion of <110°, and increasing age (OR, 1.08 [95% CI, 1.04-1.14]) and greater BMI (OR, 1.14 [95% CI, 1.05-1.23]) were significantly associated with postoperative extensor lag of >5°. Current smoking status (OR, 15.44 [95% CI, 3.97-65.90]) and concomitant retinacular tears (OR, 9.62 (95% CI, 1.67-184.14]) were associated with postoperative complications, and increasing age (OR, 1.05 [95% CI, 1.02-1.08]) and greater BMI (OR, 1.08 [95% CI, 1.02-1.14]) were associated with risk of acquiring any poor outcome criteria. Conclusion: Patient-specific characteristics—such as increasing age, greater BMI, female sex, retinacular involvement, and current smoking status—were found to be risk factors for poor outcomes after quadriceps tendon repair. Further studies are needed to identify potentially modifiable risk factors that can be used to set patient expectations and improve outcomes.