<prompt> Heterotopic ossification is a condition in which there is deposition of bone around the joints. Which of the following parameters is the most useful for this condition -Serum calciumSerum phosphateSerum alkaline phosphataseSerum PTH  <response>: Bone scan Tc 99 three phase scan is the most sensitive for early detection of heterotropic ossification. ALKALINE PHOSPHATASE and 24hr PGE2 are screening tests for heterotropic ossification. REF:Essential ohopaedics- Maheshwari- 5th edn - pg no 53. 