The pattern of cartilage damage in antero‐medial osteoarthritis of the knee and its relationship to the anterior cruciate ligament

Abstract

Within antero-medial gonarthrosis (AMG) of the knee, there is a spectrum of damage seen in the functionally intact anterior cruciate ligament (ACL). Our aim was to correlate the degree of ACL damage to the geographical extent and degree of cartilage loss on the tibial plateau. Ninety tibial plateaus resected during unicompartmental arthroplasty were photographed and digitally mapped. The ACL damage was graded (0: normal, 1: synovium loss, 2: longitudinal splits), and dimensions of full thickness cartilage loss and damage recorded. The percentage of full thickness loss in patients with a normal ACL was compared to those with a damaged, but functionally intact ligament. All specimens showed similar elliptical loss of cartilage in the antero-medial part of the tibial plateau. A total of 45(50%) patients had a macroscopically normal ACL, 21(23%) had synovial loss, and 24(27%) had longitudinal splits. An increase in the area of cartilage damage was seen with progressive ACL damage (p < 0.001). The area of macroscopically normal cartilage found posteriorly did not change. This study demonstrates that phenotypic distribution of cartilage damage in AMG is highly reproducible with a pattern of increasing cartilage erosion associated with increasing ACL damage.

Patterns of Compartment Involvement in End‐stage Knee Osteoarthritis in a Chinese Orthopedic Center: Implications for Implant Choice

“…However, a functionally intact ACL is still critical for the long‐term outcome of medial UKA, and failure of UKA would be expected in those with ACL‐deficient knees. An intact ACL could maintain the stability of the knee and limit cartilage erosion of both the antero‐medial tibial plateau and femoral condyle. One reliable method to determine the structural integrity of the ACL is to observe the bone erosion pattern of the medial plateau on the lateral radiographs.…”

A gene expression study of normal and damaged cartilage in anteromedial gonarthrosis, a phenotype of osteoarthritis

“…The most common phenotype of knee OA, Anteromedial Gonarthrosis (AMG) provides a spatially reproducible pattern of disease. AMG affects up to 60% of patients presenting with knee OA and is characterized by: full thickness cartilage loss in the anterior third of the medial tibial plateau; partial thickness loss of the middle third; and a macroscopically and histologically normal region in the posterior third 12 . Thus AMG provides a spatial representation of cartilage degradation in OA, allowing comparison of undamaged and damaged cartilage from microanatomically defined regions [Fig.…”

Clinical outcome after UKA and HTO in ACL deficiency: a systematic review

“…Patients with a primary ACL injury who develop secondary OA are typically young and active, and in these patients the disease pattern in the medial tibial plateau is typically more posterior than the antero-medial OA seen in patients with an intact ACL, [19,36,45]. Conversely, patients with primary OA who develop secondary ACL instability tend to be comparatively older and less active with a more extensive pattern of disease across both the medial and lateral compartments.…”