<prompt> A patient presents with heterotopic ossification around the knee joint. The laboratory investigation of choice in him is which of the following?Serum calciumSerum Alkaline PhosphataseSerum phosphorusSerum Acid phosphatase  <response>: Heterotopic ossification is characterised by periaicular deposition of ectopic new bone. Serum alkaline phosphatase is an impoant marker of osteoblastic activity and new bone formation. Ref: Wheeless Textbook of Ohopaedics; Garland D.E. A clinical perspective on common forms of acquired heterotopic ossification CORK No Feb, 1991; Other Journal aicles; Schiffs dieases of the liver - Eugene R Schiff Page number 26. 