A cadaveric investigation into the links between macroscopic and microscopic osteoarthritic changes at the hip

Abstract

Our objective was to investigate the frequency and distribution of osteoarthritic changes at the hip, including the relationship between osteoarthritic lesions on the femoral head surface and histological changes in articular cartilage, in 12 cadavers. Twelve embalmed cadavers (five males and seven females) were dissected, and the femoral head was removed from both sides (24 femoral heads). Any gross osteoarthritic changes were noted and graded (on a scale of 1-3). A circular disc was then removed from the equator of the femoral head and divided into nine regions. Out of 192 segments, 54 underwent sectioning and staining with haematoxylin and eosin to assess histological changes in cartilage. Osteoarthritis of the hip was present in all cadavers, with all males having bilateral OA and 50% having grade 2 or higher lesions (50% were grade 1), and four of the seven female specimens having bilateral OA and only 7% with grade 2 lesions (with 71% grade 1 and 21% normal). Chondrocyte clustering was most commonly observed in the deep layer of cartilage followed by the intermediate and superficial layers respectively, as the grade of the macroscopic lesion increased. Cartilage injury at the histological level precedes any visible denudation of the femoral head articular cartilage. This study supports the hypothesis that early osteoarthritic changes occur in the deep layer of cartilage near the tide mark and progress superficially concomitant with an overall increase in the osteoarthritic lesion size on the femoral head surface.

Assessing macroscopic and microscopic indicators of osteoarthritis in the distal interphalangeal joints: A cadaveric study

“…Fibrillation, on the other hand, becomes detectable only once a lesion has become visible to the unaided eye (i.e., in Grades 1-3). Our results differ slightly but importantly from Agha and Webb's (2006) investigation of OA at the hip joint. These researchers found all grossly normal specimens to be completely devoid of cartilage fibrillation and tide mark irregularities.…”

“…The visual confirmation of degraded joint surfaces following dissection can easily identify the early stages of OA, whereas the radiographic visualization of joint space narrowing will not occur until later in the progression of the disease. A similar disparity was seen when Agha and Webb (2006) investigated OA at the hip in cadavers and compared their prevalence rates with previous radiographic studies. Newer imaging techniques in radiology such as CT and MRI have improved on the ability to detect OA.…”

“…Specimens were examined for specific indicators of OA including (1) presence of fibrillation, (2) changes in the tide mark, and (3) chondrocyte clustering (defined as more than two chondrocytes per chondron; Agha and Webb, 2006). The trichrome-stained slides were used to better visualize tide mark irregularities.…”

“…General histological observations indicated that clustering of chondrocytes (defined as more than two chondrocytes per chondron; Agha and Webb, 2006) occurred more frequently towards the superficial layer of articular cartilage. In some specimens, however, evidence of clustering was apparent even within deeper regions (Fig.…”

“…Instead, the main etiological event causing destruction of the cartilage may occur within the cartilage itself and not in the subchondral bone, although changes in the bone may play some role (e.g., Burr and Schaffler, 1997;Raudenbush et al, 2003). Agha and Webb (2006) used histological methods to investigate osteoarthritic changes at the hip joint and found that subchondral bone changes possibly initiated the degradation of the joint. These results are of particular interest because the hip is the joint most commonly affected by OA (Felson, 2004).…”