Gender Disparity between Donor Sites of the Trochlea Used for Autologous Osteoarticular Transfer: An MRI Analysis.

Abstract

The purpose of this study was to assess potential gender differences in size of the lateral and medial trochlea of the male and female knee as well as the variation within gender of potential osteochondral autograft transfer (OAT) donor site area. Two hundred and twelve skeletally mature patients, 106 males and 106 females, who underwent a 3T magnetic resonance imaging of the knee for a variety of indications were utilized for analysis. Exclusion criteria included degenerative arthritis, trochlear dysplasia, and poor image quality. Medial and lateral femoral trochlear cartilage width was obtained using a linear radiologic measurement tool. Widths were measured from a reproducible anatomic location representing the maximal trochlear dimension in a region where donor plugs are commonly harvested. Trochlear width was also plotted as a function of patient height. Statistical analysis was performed using a two-sample t-test. The mean and standard deviation of the lateral trochlear cartilage width (mm) for males and females were 23.38 +/- 2.14 and 20.44 +/- 2.16, respectively (p < 0.00001). The mean and standard deviation of the medial trochlear cartilage width (mm) for males and females were 14.16 +/- 2.17 and 11.78 +/- 2.03, respectively (p < 0.00001). The overall range in trochlear width for both the lateral and medial sides was 22.22 and 19.73 mm for males and females, respectively. A graft measuring 10 mm could represent as little as 34% of the lateral trochlea in males versus as much as 65% in females. Our results indicate that donor OAT plug diameter relative to available trochlear cartilage width will vary significantly both between genders and individual patients. Trochlear width variability and its potential implications on donor site morbidity may be an important consideration when contemplating osteochondral plug harvest for OAT or other indications. The level of evidence is IV.