/43/3/346.full.pdfThe above mentioned article writes- "Alkaline phosphatase has been recommended as a useful screening tool for heterotopic ossification (HO). ....Nonetheless, this inexpensive and easily obtained test is frequently used to detect early HO."Heterotopic ossification (HO) is the presence of bone in soft tissue where bone normally does not exist.It is of 2 types:the more common acquired form &the very rare hereditary form known as myositis ossificans progressiveCauses of acquired form:Traumatic cause- acquired form of HO may occur after virtually any type of musculoskeletal trauma. For example, HO may occur after orthopedic procedures such as hip, knee, shoulder, or elbow arthroplasty; fractures; joint dislocations; or soft-tissue trauma,Neurogenic cause- such as spinal cord injury or central nervous system injury (usually without direct trauma to the soft tissues, where bone formation will occur)This condition should not be confused with metastatic calcification--such as may be seen with hypercalcemia-- and dystrophic calcification, which occurs in morbid tissues such as tumor.Early symptoms are: pain, fever, swelling, erythema, and decreased joint mobility.Later, reduced range of motion and ankylosis of the joint may occur.Investigations:Alkaline phosphatase and 24-h PGI 1/4 urinary excretion measurements are recommended as screening tests for HO.Three-phase bone scintigraphy is the most sensitive imaging modality for early detection of HO.Treatment of HOComplications of HO include peripheral nerve entrapment, pressure ulcers, and functional impairment if joint ankylosis develop. Therefore, prophylaxis or early treatment of HO is extremely important.Treatment or prophylaxis of HO includes:passive range of motion exercisesnonsteroidal antiinflammatory drug (such as indomethacin), or a diphosphonate (such as ethane-1-hydroxy-1,1- diphosphate).local radiation therapysurgery can also be done to relieve functional impairment of joint.">