The Geometry of the Trochlear Groove

Abstract

Our study shows the importance of reliable femoral orientation when reporting the shape of the trochlear groove.

The 3D analysis of the sagittal curvature of the femoral trochlea in the Chinese population

“…Another limitation was that the CT scanned images were used to construct the 3D distal femur, which did not contain the cartilaginous surfaces. Although some studies have shown the geometry of the cartilage surface differed from that of the bone in the trochlea, the difference was small [13]. Thirdly, though the anatomical prosthesis design of the femoral trochlea help to restore the natural patellar tracking, the actual circularity of the patellar path may be altered by variations on the patellar side such as with/without resurfacing, overstuffing, or understuffing of the joint [12].…”

Patient-specific modeling of the trochlear morphologic anomalies by means of hyperbolic paraboloids

“…Figure 8) showed on average a slightly greater flatness of the lateral than the medial facet in agreement with the anatomical difference between the two facets. [11,12] Specific results demonstrated robustness of these two parameters in the description of similar geometries and appropriate sensibility to discriminate even small variations of facet curvature as well (cfr. Figure 9).…”

“…[6][7][8][9][10] Evaluating the morphologic deviations to normality is however complicated by the fact that the three-dimensional (3D) geometric profile of the trochlea is extremely complex and sensibly varies amongst individuals. [11][12][13] One of the most applied clinical approach to score the morphologic anomalies of the trochlear surface (TS) is based on the Dejour classification, which encompasses four different qualitative Grades (A, B, C, D) of increasing severity. [14,15] Based on radiological assessment, the evaluation is performed by means of clinical signs, such as the shape of the groove, the roundness of the two facets and their absolute and relative sizes.…”

“…[2,16,17] Morphometric parameters, such as the trochlear depth, the sulcus angle, the lateral trochlear facet inclination and the trochlear facet asymmetry ratio, to cite the most relevant, are based on anatomical landmarks manually digitized in computed tomography (CT) and magnetic resonance (MR) images. [12,[18][19][20][21] The use of such parameters have been criticized as well because of difficulties in the precise localization of landmarks, especially in case of large morphologic deviations, [20] dependency on the adopted measurement protocol [2,5,17] and interobserver variability. [22] These issues further complicate the definition of absolute cut-off values adopted to discriminate between normal and abnormal morphologies and even to identify different severity grades.…”

Automating the design of resection guides specific to patient anatomy in knee replacement surgery by enhanced 3D curvature and surface modeling of distal femur shape models

“…1a), the detection of such two points as bony landmarks, both in images and intra-operatively on the patient bone, can be unreliable. The trochlear groove is typically a concave region whose the deepest part is however not easy to simplify to a single point [35]. The identification of the intercondylar notch can be affected by uncertainty, as well.…”