Cervical spine dislocation under AMA 4 , with the injury model, " surgery to treat an impairment does not modify the original impairment estimate, which remains the same in spite of any changes in signs or symptoms that may follow the surgery and whether the patient has a favourable or unfavourable response to treatment". In AMA 4 , the injury model bases impairment on the result of injury ( e.g. minor injury, radiculopathy,loss of motion segment integrity, etc) , not the treatment (e.g. conservative, surgery without fusion, fusion etc).Impairment DOES NOT consider the improvements or detriments of surgery which does not seem fair.
In AMA 5 , significant changes were made.Surgery to treat an injury may modify an impairment and the performance of say a single -level ACDF results in the minimum DRE Category IV rating.AMA 5 explains that "in prior editions of the Guides, rating spinal cord injury was done either through a combination of DRE categories or in the nervous system chapter. It was decided in this Edition(AMA 5) to evaluate SCi based on the criteria in the nervous system chapter-13 ".Because of the multiple neurological impairments present in cord injuries , AMA 5 resultant impairments are generally higher than those using AMA 4, and are considered more equitable.
ASSISTANT PROFESSOR MICHAEL CORONEOS CIME MASE
SENIOR NEUROSURGEON & PI ASSESSOR
NATIONAL RACS EXAMINER & SENIOR RACS MORTALITY ASSESSOR (QASM).
MEMBER of ACADEMY of SURGICAL EDUCATORS
FAIM FACS FRCSI FRACS FRCS(EDIN)SN MB BS(1ST CLASS HONOURS) MNSA MNSQ MAPS MANZSOM CIME MASE