Prostaglandin E2 measurements: their value in the early diagnosis of heterotopic ossification in spinal cord injury patients.

OBJECTIVE: To look for a possible relation between the occurrence of heterotopic ossification (HO) and the modifications of the 24-hour prostaglandin E2 (PGE2) urinary excretion. DESIGN: A 5-year prospective study to determine the 24-hour urinary excretion of PGE2 by radioimmunoassay with specific antisera not cross-reacting with TXA2, TXB2, 15-keto-PGE2 alpha, PGI2, 6-keto-PGF1 alpha. SETTING: The laboratory of a division of endocrinology and diabetology of a university hospital. PATIENTS: Of 262 acute spinal cord injury patients screened, 44 were eligible for the study. INTERVENTIONS: Serial diagnostic quantitative bone scannings with technetium 99m Tc methylene diphosphate (99mTc-MDP) and therapeutic assessment of radiotherapy and indomethacin. MEAN OUTCOME MEASURE: Hypothetical increase of PGE2 before and during HO formation. RESULTS: Of 44 patients, 8 developed an HO (18.8%) with concomitant marked increase of the PGE2 excretion for as long as the HO had not reached maturity. The results of the radiotherapy were inconclusive. Indomethacin was shown to be efficacious in holding back or slowing down the HO evolution. CONCLUSIONS: Measurement of the 24-hour PGE2 urinary excretion appears to be a valuable indicator in the early diagnosis of HO. Indomethacin should be considered as an alternative to other existing therapies.