Stress fracture of the patella in a palmwine tapper.

Stress fracture of the patella in a twenty-nine-year-old palmwine tapper is reported. The fracture occurred during a busy tapping day which was his first working day after a ten-day sick off for a febrile illness and presentation was delayed for six weeks. Initial diagnosis was pathological fracture, but X-ray examination and histology of the biopsy from the fracture site did not suggest any associated disease. The pathomechanics of palmwine tapping is very similar to jumping (parachute) which is the usual cause of this fracture in developed countries.