Cartilage lesions of the patella in recurrent patellar dislocation.

BACKGROUND

The etiology of patellar cartilage lesions in recurrent patellar dislocation has been poorly understood.

HYPOTHESIS

The pathology of cartilage lesions of the patella accompanied by recurrent patellar dislocation can be analyzed.

STUDY DESIGN

Series of case reports.

METHODS

In 70 knees from 57 patients with recurrent patellar dislocation, the cartilage lesions of the patella were examined using arthroscopy and/or macroscopic observation. The average age of the patients was 22 years (range, 13 to 40 years). Lesions that involved only softening were not included.

RESULTS

Sixty-seven knees (96%) had articular cartilage lesions of the patella, and only 3 knees had no change. Fissuring was observed in 53 knees (76%). The most common site of fissuring was on the central dome. There were basically two types of fissuring: multiple longitudinal fissuring and marginal/radial fissuring. Fibrillation and/or erosion were observed in 54 knees (77%). Of these, 40 knees had fissuring and 14 did not have fissuring. The main site of fibrillation and/or erosion was the medial facet.

CONCLUSIONS

Cartilage lesions of the patella in recurrent patellar dislocation cases were very common. Fissuring was observed mainly on the central dome, and fibrillation and/or erosion were observed mainly on the medial facet.