Morphological changes in the shape of the non‐pathological bony knee joint with age: a morphometric analysis of the distal femur and proximal tibia in three populations of known age at death

Abstract

This study examines possible morphological variation in the knee joint of Homo sapiens with increasing age in ostensively healthy and non-pathological distal femora and proximal tibiae. Throughout the lifetime of each individual, the hard tissue of the knee undergoes considerable remodelling as a response to biomechanical stresses, changes in bone microarchitecture and reduction of bone mineral content as a concomitant of ageing. The knee is also subject to greater levels of degenerative joint disease than any other joint. If death occurs whilst such diseases are in the earliest stages, initial bone changes may not be visually obvious in museum specimens. If such specimens are used for comparative analyses, it is hypothesised that changes might render it problematic if all ages are conglomerated into discrete samples. This study therefore investigates the degree to which the distal femur and proximal tibia change shape during ageing and, if changes are present, whether they are expressed similarly in males and females. It also examines whether changes are of greater magnitude than those morphological differences which might exist between populations. In an example population of African-Americans, results indicate that there is a statistically significant difference in shape between age groups and those differences become progressively greater between the youngest and oldest adults. Results also show that although morphological variation caused by ageing is apparent, those shape differences attributable to sexual dimorphism are more powerful. When two additional populations are analysed jointly with the African-Americans (Caucasian Americans and the European Spitalfields sample), results indicate that inter-population shape differences are considerably greater than differences caused by increasing age. Results imply that it is justifiable to combine specimens of all ages into discrete samples for comparative purposes.

Sexual Dimorphism of the Human Tibia through Time: Insights into Shape Variation Using a Surface-Based Approach

“…Recent geometric morphometric studies exploring age changes in the proximal tibia have revealed that although age-dependent shape variation is apparent and significant, inter-population and sex-related shape differences are considerably more important [6,9]. In the tibial shaft, where we saw the most marked SD, cross-sectional geometry age changes take the form of continuous expansion during adulthood (for review see [70]).…”

“…The issue of human tibia design has been studied extensively, but research has predominantly dealt only with shape variation of the shaft [2–5]. A few studies have focused on the shape of the articular ends [6–9] and even fewer have considered the whole tibial external geometry [10,11]. …”

“…Such methods can communicate complex shape changes much more effectively, and provide information on morphological changes in their immediate anatomical context. In the tibia, landmarks can be defined reliably only at its proximal and distal extremities, and shape differences are visualized as relative shifts of landmark positions in starting and target shapes [6,9,12]. A somewhat larger part of the shape can be captured by semi-landmark-based approaches [11] but still relatively large portions of the bone cannot be examined and some information is lost to analysis.…”

Bone morphology of the femur and tibia captured by statistical shape modelling predicts rapid bone loss in acute spinal cord injury patients

“…The few studies that have assessed distal femur or proximal tibia shape have assessed it in the context of knee osteoarthritis or clinical studies looking to predict outcome of interventions based on bone morphology. Interestingly all these studies noted differences in the femoral intercondylar notch shape associated with either osteoarthritis or the success of cruciate ligament reconstruction, and many proposed that this may arise due to differences in cruciate ligament attachment [45][46][47][48]. Differences in the shape of the distal femur based on age and sex have also been reported elsewhere [46].…”

Morphological Characteristics of Healthy and Osteoarthritic Joint Surfaces in Archaeological Skeletons

“…Three‐dimensional Cartesian coordinates of landmarks were digitized on the joint surfaces using a Microscribe® GLS digitizing system (EMicroscribe Inc) (Figures a–c). Landmarks for the distal femur were based on those used by Stevens & Strand Viðarsdóttir (). These landmark data were then superimposed using generalized Procrustes analysis, which removes all scale and translational variation from the data (Goodall, ); size information in the form of centroid size was retained as an independent variable.…”