Articular cartilage thickness at the distal radius: a cadaveric study

Articular stepoffs that occur after fracture and are greater in size than the thickness of the articular surface seem to result in arthritis. The thickness of a joint's cartilage may, therefore, set the limit for acceptable stepoff when treating fractures. The goal of our study was to determine the thickness of the articular cartilage at the distal radius.

We conducted a cadaveric study of 19 wrists to measure the thickness of cartilage at the distal radius. After harvest, we made multiple slices of each radius and used a standardized technique to directly measure the articular cartilage in the scaphoid and lunate fossae and along the interfossal ridge.

The average cartilage thickness in our cohort was 0.6 mm. The average articular surface thickness was < 1 mm in all measured areas (scaphoid fossa, 0.7 mm; interfossal ridge, 0.8 mm; lunate fossa, 0.6 mm). Among the samples, 98% had an average thickness of < 1 mm. The maximum recorded thickness was 1.1 mm.

Our study quantifies the thickness of the articular cartilage at the distal radius. Our finding of cartilage thicknesses of < 1 mm is consistent with multiple clinical studies, suggesting that stepoffs of > 1 mm result in radiographic signs of arthritis. This provides further evidence linking the thickness of articular cartilage to radiographic outcomes and, possibly, clinical outcomes.

Our findings provide anatomic support for using 1 mm or less as an acceptable articular stepoff size in the treatment of fractures of the distal radius.