Cartilage thickness of the talar dome.

PURPOSE: To perform a successful operation, accurate information on the articular cartilage thickness of the talus is essential. The purpose of this study was to determine the articular cartilage thickness of the talar dome in the area where osteochondritis dissecans is common.

TYPE OF STUDY: Convenient samples.

METHODS: Articular cartilage thickness of the mid talar dome was measured in 29 ankles of 17 cadavers. The average age of the specimens was 70 years (range, 53 to 91 years). Twenty-two were from men and 7 were from women. Coronal sections of the mid talar domes were obtained from the specimens measuring 2 mm in width and 5 mm in depth. Radiographs of the sectioned specimens were taken and were enlarged with a personal computer. The thickness of the articular cartilage was measured at 9 areas: medial gutter (area 1), medial corner (area 2), medial edge of the dome plateau (area 3), lateral edge of the dome plateau (area 7), lateral corner (area 8), lateral gutter (area 9), and quarter points between areas 3 and 7 (areas 4, 5, and 6).

RESULTS: The average thickness of the total areas was 1.35 +/- 0.22 mm in the male specimens and 1.11 +/- 0.28 mm in the female specimens. The thickest was area 2, which represented the medial corner, and the thinnest was area 9, which represented the lateral gutter in both men and women. There was a relationship between the thickness of the cartilage and the width of the talar dome.

CONCLUSIONS: The thickness was usually less than 2 mm. However, the cartilage thickness varies widely by gender, area, and individual.

CLINICAL RELEVANCE: Our report will help surgeons predict the volume of cartilage that needs to be repaired and produce treatment at a reasonable cost without an excessive invasion of patients.