The end of avascular necrosis in DDH?
Avascularnecrosis can be a result of medical malpractice, either due to incorrectly applied orthopaedic casts or incorrectly worn orthopaedic appliances (we constantly advise our patients on the proper way of wearing of such equipment). However, this does not apply to the necrosis of head of femur in newborns in case of underdevelopment of the acetabulum. Maybe it’s time to change that.
The currently available technology makes it possible to use the USG equipment to monitor the supply of blood to the hip joints (or lack thereof). However, their availability in orthopaedic departments of hospitals is extremely low, and they are nearly non-existent in infant orthopaedic clinics. Because of the costs, high-end usg equipment is nearly impossible to find in Polish medical facilities. And the lack of awareness among orthopaedists and parents, who don’t pressure the potential decision makers who could change the situation for better, does not help either.
Several rules on how to avoid this:
1) Full abduction of the femur at the hip joint always causes a closure of blood vessels. It is the most common Despite being the most common healing position, it should be avoided or performed to a limited extent only. The regenerative abilities of newborns are truly incredible, and bone recovery usually takes 2-3 weeks for them. Slower than normal recovery of acetabulum (taking up to several months) is most commonly caused by circulatory disorders. After all, proper recovery requires a proper blood flow.
Orthopaedic appliances, especially casts, should only be applied under USG monitoring. The abduction angle at which a closure of blood vessels occurs can vary from 45º to 90º. Likewise, the angle at which ischemia might occur can also vary – from 5º to 15º.
2) “Asymmetries” of abductions and muscle contractures can be eliminated by means of regular gentle exercises (3 times, 20 minutes each will suffice). This will improve the centring of the head of the bone, and result in less circulatory disorders.
3) You can intensify the exercises by increasing the angles of muscle abduction to 45º, rather than trying to achieve results by means of additional orthopaedic appliances or anaesthesia. The stronger the abduction, the better the centring of the head in the acetabulum, and the lower the movability of the head of the bone in the acetabulum. Low movability also prevents its expansion and slows down its wear in the future.
4) In case of stable joints, the exercises should be performed with intervals – preferably with a ~several minutes long pause every hour.
5) In case of unstable joints we heal constantly with qualified breaks performed by a ortopedic. Time of therapy is limited to the minimum depending on achived stabilization, which we verify everyday.
6) Parents can provide their child with much better support than even the best orthopaedic appliances but they have to be properly instructed first.