• how long has the knee been restricted like this ? since the accident or only recently?
  • how old is the patient?
  • how are her quads ?
  • does she resist attempts to flex the knee ?
  • meniscal tests?

I had a patient once (~12-14yr girl) who was involved in a severe boating accident (fatalities involved) and was told at some time by a doctor if she didnt rest her leg and keep it straight it would need to be amputated like one of her friends had to.(she had some minor injuries but nothing significant from memory).

She was a year or so later diagnosed by the rehab team as conversion disorder and the neuro psychologist suggested treating it as a musculoskeletal problem. She couldnt flex her leg, and we couldnt flex her leg. She would sit and walked with a straight leg all the time.
Sleep studies however showed that it would bend when asleep.

I tried to fatigue her into flexion once with about 30kg of ankle weights on her leg. 20minutes, nothing changed ! We discharged her after a long time with no result. The neuro-psychologist would rather we continued, but it was pointless. About 2 years later she just started to bend her leg as if nothing was wrong...


Some things arent always simple, and not always musculoskeletal in origin...
good luck