Sex and site differences in cartilage development: A possible explanation for variations in knee osteoarthritis in later life

Abstract

Objective. To test the hypothesis that sex-related and joint compartment-related differences in the risk of osteoarthritis (OA) of the knee might be associated with variations in cartilage development, we investigated knee cartilage volume in healthy children. Methods. We studied 92 children who were randomly selected from among students in grades 3-12 of a single school in Hobart, Tasmania (49 boys, 43 girls; age range 9-18 years). Articular cartilage thickness and volume were determined at the patella, medial tibial compartment, and lateral tibial compartment by magnetic resonance imaging (MRI). Sagittal T1-weighted fat-suppressed MRI images were obtained and processed on an independent computer work station. Results. Males had significantly more knee cartilage than females. Sex accounted for 6-36% of the variation in cartilage thickness and volume, which was statistically significant at all sites. Even after adjustment for age, body mass index, bone area, and physical activity, males had 16-31% higher cartilage volume; this was most marked at the medial tibial site. In addition, lateral tibial thickness was greater than medial tibial thickness (5.9 versus 3.6 mm; P < 0.0001) and lateral tibial volume was greater than medial tibial volume (2,823 versus 2,299 l; P < 0.0001). Furthermore, physical activity was a significant explanatory factor for cartilage volume at all sites (R 2 7-14% depending on site; all P < 0.05). The most consistent activity association was with vigorous activity in the previous 2 weeks (difference between any vigorous activity versus none 22-25% greater; all P < 0.05). Conclusion. Sex-and joint compartment-related differences in cartilage development may be one explanation for variations in the pattern of knee OA seen in later life. Furthermore, the physical activity associations suggest that cartilage development is amenable to modification. Osteoarthritis (OA) is the major cause of disability in persons over the age of 65 years (1). Sex-related and joint compartment-related differences in knee OA are well described. Women have a 1.5-4 times higher risk than men (2) while medial compartment disease is 4 times more common than lateral compartment disease (3). The reasons for these variations are unclear at the present time. There is convincing evidence that other diseases of later life, such as ischemic heart disease, diabetes mellitus, and particularly, osteoporosis, are associated with childhood development (4,5). Although there are no data in humans with regard to early life exposures and risk of OA, a study in senescent moose linked a higher incidence of OA with a famine when the moose were weanlings (6). Defects in cartilage are widely considered to be the initial problem in OA (7), although this viewpoint is not shared by all investigators (8). However, cartilage development is poorly understood, and descriptive or etiologic data are few. In part, this is due to the lack of a noninvasive, accurate, in vivo method of assessing cartilage. Recently, magnetic resonance imaging (MRI) ha...

Longitudinal study of changes in tibial and femoral cartilage in knee osteoarthritis

“…If symptomatic OA was present in both knees, the knee with less severe OA as determined radiographically was studied. The patients' knees were imaged in the sagittal plane on a 1.5T whole-body MR unit (Sigma Advantage GE Medical Systems; Milwaukee, WI) with use of a commercial receive extremity coil as previously described (3,4). The method to transform the images to the coronal plane has also been described previously (5).…”

“…The method is reproducible, with coefficients of variation (CVs) of ϳ2% (2-4). This technique has been used to explore factors that influence knee cartilage in healthy adults and children (3,4).…”

Correlation of knee‐joint cartilage morphology with muscle cross‐sectional areas vs. anthropometric variables

“…In conjunction with state-of-the-art three-dimensional (3D) postprocessing tools (qMRI) the technique has been shown to produce accurate and precise data on the cartilage morphology (volume, thickness, and surface area) of the knee in healthy individuals (Stammberger et al, 1999a;Hohe et al, 2002), and in patients with femorotibial osteoarthritis (OA) (Burgkart et al, 2001). Various studies have revealed that the knee-joint cartilage volume displays a high intersubject variability (Eckstein et al, 1998a(Eckstein et al, , 2001aCicuttini et al, 1999;Jones et al, 2000), but little is known about the determinants of this variability. Several authors (Karvonen et al, 1994;Cova et al, 1996;Dalla Palma et al, 1997;Eckstein et al, 1998aEckstein et al, , 2001aCicuttini et al, 1999;Jones et al, 2000) have investigated the correlation of knee-joint cartilage morphology with anthropometric variables such as body height, body weight, and age.…”

“…Various studies have revealed that the knee-joint cartilage volume displays a high intersubject variability (Eckstein et al, 1998a(Eckstein et al, , 2001aCicuttini et al, 1999;Jones et al, 2000), but little is known about the determinants of this variability. Several authors (Karvonen et al, 1994;Cova et al, 1996;Dalla Palma et al, 1997;Eckstein et al, 1998aEckstein et al, , 2001aCicuttini et al, 1999;Jones et al, 2000) have investigated the correlation of knee-joint cartilage morphology with anthropometric variables such as body height, body weight, and age. Body height and weight have been shown to be only weakly correlated with cartilage volume (Dalla Palma et al, 1997;Eckstein et al, 1998a;Cicuttini et al, 1999;Jones et al, 2000), and in particular with cartilage thickness (Karvonen et al, 1994;Eckstein et al, 2001a).…”

“…Several authors (Karvonen et al, 1994;Cova et al, 1996;Dalla Palma et al, 1997;Eckstein et al, 1998aEckstein et al, , 2001aCicuttini et al, 1999;Jones et al, 2000) have investigated the correlation of knee-joint cartilage morphology with anthropometric variables such as body height, body weight, and age. Body height and weight have been shown to be only weakly correlated with cartilage volume (Dalla Palma et al, 1997;Eckstein et al, 1998a;Cicuttini et al, 1999;Jones et al, 2000), and in particular with cartilage thickness (Karvonen et al, 1994;Eckstein et al, 2001a). Considering that cartilage thickness may depend on the "loading history" of the joint (Kurrat and Oberlä nder, 1978;Mü ller-Gerbl et al, 1987;Carter et al, 1991;Eckstein et al, 1992;Adam et al, 1998), muscle cross-sectional areas (MCSAs) and muscle forces may provide better estimates of cartilage morphology than body height and weight or other anthropometric variables, because MCSAs have been shown to be strongly associated with muscle strength (Maughan et al, 1983;Brand et al, 1986), whereas joint loads are mainly determined by muscle force .…”