Name
OSTEITIS DEFORMANS
DESCRIPTION
DETAIL
CAUSES Unknown; best evidence to date is for slow virus infection in genetically susceptible individuals -------------------------------------------------------------------------- DIFFERENTIAL DIAGNOSIS β’ Polyostotic fibrous dysplasia β’ Osteitis fibrosis cystica (skeletal hyperparathyroidism) β’ Primary bone neoplasms β’ Osteolytic, osteoblastic metastasesLABORATORY β’ Serum calcium - usually normal, rarely increased β’ Serum alkaline phosphatase (total or bone specific) - usually increased β’ Serum GGT - normal β’ Serum osteocalcin (BGP) - usually increased β’ Urinary pyridinoline collagen crosslinks - usually increased β’ N- and C-telopeptide (collagen crosslinks) - usually increased in serum and urine SPECIAL TESTS β’ Neurologic examination β’ Audiogram, if skull involvement β’ Visual field study, if skull involvement IMAGING β’ X-rays show irregular pattern of alternating bone formation and resorption in enlarged deformed bones. Resorptive fronts at advancing edge. β’ Bone scans show intense uptake in focal pattern β’ CT/MRI show extra-bony extension if sarcomatous degeneration occurs DIAGNOSTIC PROCEDURES Bone biopsy needed only in confusing cases (rare)
TYPENOTES
GENERAL MEASURES β’ Rarely, splints for severely resorbed areas with high risk of fracture β’ Hearing aids for severe deafness; of some (but not great) value in sensorineural deafness SURGICAL MEASURES β’ Joint replacement (hip, knee) sometimes needed β’ Osteotomy procedures for extreme deformity β’ Decompression procedures (skull, spinal column) for acute neurologic defi cits (rarely needed) β’ Bone biopsy (rarely needed) β’ Extirpative surgery for sarcomatous complications β’ Open reduction of fractures ACTIVITY β’ Full activity to maintain function β’ Avoid excessive mechanical stress on involved bones DRUG(S) OF CHOICE β’ Synthetic injectable salmon calcitonin (Miacalcin): 50 IU three times weekly to 100 IU qd, courses 1.5 to 3 years β’ Etidronate (Didronel), 5 mg/kg/day (approximately 400 mg) x 6 mos (taken on an empty stomach). Rarely, 20 mg/kg/day x 1 month. Courses may be repeated after a 3-6 month rest period β’ Alendronate (Fosamax) 40 mg/day (taken on an empty stomach) for 6 mos β’ Risedronate (Actonel) 30 mg/day (taken on an empty stomach) for 2 months β’ Pamidronate (Aredia) 60 mg/day by 4-6 hour infusions for 2-3 days. Alternately, 30 mg/day by 4-6 hour infusions once a week for 6 weeks. May be repeated several months later if effect wears off. β’ Add non-steroidal anti-infl ammatories (NSAIDs) to above drugs for secondary osteoarthritis. COX-2 inhibitors may be substituted. ALTERNATIVE DRUGS NSAIDs or COX-2 inhibitors for mildly symptomatic disease in nonstrategic areas PATIENT MONITORING β’ Followup visits every 2-4 months during drug therapy; yearly if drugs not being used. Alkaline phosphatase (total or bone specifi c) before each visit. β’ Repeat x-rays and bone scan every 3-5 years or as needed PREVENTION/AVOIDANCE Avoid excessive mechanical stress on affl icted bones to reduce chance of fractures and other complications POSSIBLE COMPLICATIONS Fractures, severe deformities, head enlargement, acetabular protrusion, carpal/tarsal tunnel syndromes, neurologic deficits, deafness, visual impairment, congestive heart failure (high output), renal calculi, Peyronie syndrome, sarcomatous degeneration EXPECTED COURSE/PROGNOSIS β’ Depends on severity, often asymptomatic β’ Slow progression if untreated β’ Significant amelioration with treatment (85% or greater) β’ Poor prognosis if bone sarcoma develops
RELATED DISEASE
Not Available Disease
DISEASE
INVESTIGATION
SERUM ALKALINE PHOSPHATASE, SERUM CALCIUM, BONE SCAN, GAMMA GLUTAMYL TRANSFERASE ( GGTP / GGT ) - FEMALE, COMPLETE BLOOD COUNT, MRI, CT SCAN, X-RAY, BIOPSY