The Relationship between Anterior Cruciate Ligament Injury and Osteoarthritis of the Knee

Abstract

Anterior cruciate ligament (ACL) tears are a common injury, particularly in the athletic and youth populations. The known association between ACL injury and subsequent osteoarthritis (OA) of the knee merits a more in-depth understanding of the relationship between the ACL-injured knee and osteoarthritis. ACL injury, especially with concomitant meniscal or other ligamentous pathology, predisposes the knee to an increased risk of osteoarthritis. ACL insufficiency results in deterioration of the normal physiologic knee bending culminating in increased anterior tibial translation and increased internal tibial rotation. This leads to increased mean contact stresses in the posterior medial and lateral compartments under anterior and rotational loading. However, surgical reconstruction of the ACL has not been shown to reduce the risk of future OA development back to baseline and has variability based on operative factors of graft choice, timing of surgery, presence of meniscal and chondral abnormalities, and surgical technique. Known strategies to prevent OA development are applicable to patients with ACL deficiency or after ACL reconstruction and include weight management, avoidance of excessive musculoskeletal loading, and strength training. Reconstruction of the ACL does not necessarily prevent osteoarthritis in many of these patients and may depend on several external variables.

Figure 1

AP and sunrise knee radiographic images of a 29-year-old male patient at (a-b) 8 months and (c-d) 30 months after an acute ACL injury. The images show progression of osteoarthritic changes in a young male with an ACL-deficient knee.

Figure 2

(a) Anteroposterior (AP) and (b) sunrise view of the right knee in a 39-year-old female patient who underwent ACL reconstruction with medial meniscectomy at the age of 33 after sustaining an ACL tear with concomitant medial meniscus and MCL tears. These radiographs demonstrate joint space narrowing, particularly in the medial and patellofemoral compartments, consistent with early osteoarthritic changes.

Figure 3

Arthroscopic images depicting arthritic changes in the same 39-year-old female patient described in Figure 1, who underwent ACL reconstruction with medial meniscectomy at the age of 33 after sustaining an ACL tear with concomitant medial meniscus and MCL tears.