Review Question - QID 214145

The patient has sustained an isolated anterior cruciate ligament (ACL) tear of the right knee. His age places him at an increased risk of developing post-traumatic osteoarthritis (OA) following surgery.

ACL ruptures are common athletic injuries that frequently lead to symptomatic instability. If the ACL is not reconstructed, the persistent instability and altered kinematics of the knee have been found to increase the rates of secondary meniscal injury and contribute to the development of post-traumatic knee osteoarthritis. While reconstruction is often recommended in the setting of complete ACL ruptures to mitigate these complications, patients remain at increased risk for developing post-traumatic osteoarthritis. This risk has been shown to be increased among those patients who are older than 50 years and in females.

Moatshe et al. evaluated radiographic progression of arthritis in 65 patients treated with ligamentous reconstruction for multigamentous knee injuries. At final follow-up, 42% of patients demonstrated radiographic evidence of osteoarthritis in the operated knee compared to only 6% in the uninjured side. They concluded that 42% of patients developed OA 10 years after surgical treatment of knee dislocations. They also note that increased age at surgery (>30 years old) was predictive of the development of OA.

Leroux et al. evaluated the incidence of osteoarthritis following surgical reconstruction of the ACL. The authors reviewed 30,301 patients who underwent ACL reconstruction (ACLR) and matched this cohort to 151,000 patients who had not had knee surgery. They found that after 15 years, the cumulative incidence of knee arthroplasty following ACLR was 1.4%, which was 7 times greater than the cumulative incidence of knee arthroplasty among matched control patients from the general population (0.2%). The authors concluded that older age, female sex, higher comorbidity were factors that increased knee arthroplasty risk.

Bodkin et al. performed a review of a commercially available insurance database to identify new diagnoses of knee OA in patients who underwent ACLR. The authors identified 10,565 patients who underwent ACLR and noted that 12% of these patients presenting within 5 years of the surgery had a new diagnosis of knee OA. Demographic factors associated with an increased risk of diagnosis were age >50, female sex, tobacco use, and concomitant meniscal surgery.

Figures A and B are normal weight-bearing AP and lateral radiographs of the right knee. Figures C, D, and E are selective sagittal T2-weighted MRI cuts of the right knee showing an ACL rupture with an intact PCL.

Incorrect Answers:
Answers 1,2,4,5: Age >50 years has not been found to be associated with increased rates of hardware failure, delayed ligamentization, instability, or wound complications following ACL reconstruction.