Distal femur morphology and the suitability of standard guides for knee arthroplasty in the Turkish population.

Objective: The aim of this study was to evaluate the posterior condylar angle (PCA) and condylar twist angle (CTA) of the distal femur in the Turkish population and its concordance with the current standard prosthesis guides used in total knee arthroplasty (TKA).

Methods: Two hundred and forty knees of 120 Turkish subjects (60 male and 60 female) were included in this study. PCA, CTA, femoral mediolateral lengths (fML), medial femoral anteroposterior lengths (fMAP), lateral femoral anteroposterior lengths (fLAP), distances between the trochlear groove and fMAP (DBTG-fMAP), distances between the trochlear groove and fLAP (DBTG-fLAP), medial posterior condylar cartilage thickness (MPCCT) and lateral posterior condylar cartilage thicknesses (LPCCT) were measured on magnetic resonance imaging (MRI).

Results: The median CTA was 7° (range: 0°-13.0°) and the median PCA was 4° (range 0°-11.0°) (P < .0001). The median fML was 79.5 mm (range: 65.7-98.9). The median length of the fMAP was 58.2 mm (range: 46.8-69.0) and the median length of fLAP was 58.2 mm (range: 48.4-73.0). The DBTG-fMAP was 15.2 mm (range: 5.2-23.2), and DBTG-fLAP length was 21.9mm (range: 16.4-29.4). The median MPCCT and LPCCT were 2.4 mm (range: 1.6-3.6) and 2.3 mm (range: 1.2-2.8), respectively. The intraclass correlation coefficient for quantifying interobserver and intraobserver reliability showed excellent agreement regarding the PCA and CTA.

Conclusion: This study has shown us that PCA and CTA may be higher in the Turkish population. Although it is not known whether these results have any clinical utility, it may be useful for surgeons to keep this in mind to prevent femoral component malposition.

Level of evidence: Level IV, Diagnostic Study.