AMIS stands for Anterior Minimally Invasive Hip Surgery. Minimally invasive hip surgery is a new type of surgery which can have patients back on their feet much faster than before with reduced potential complications. This is thanks to a small incision and more importantly much less trauma to the underlying muscles which are not cut or detached whatsoever. This leads to a smaller scar, minimal post-operative pain and a much faster return to normal activities as the muscles do not need to recover as they do after standard traditional hip replacement.
Less invasive surgery requires no cutting of the muscle and much less dissection of normal tissues the end result is less pain during recovery
Overall minimally invasive hip replacement at Spire Yale Hospital in Wales allows faster recovery compared with more traditional methods with less complications in terms of dislocation, venous thrombosis (DVT) and infection. Trauma caused by tissue damage causes pain and swelling during part of the normal healing process. Since less invasive surgery requires no cutting of the muscle and much less dissection of normal tissues the end result is less pain during recovery.
Return to normal activities
As a result of the reduced surgical trauma and the minimal muscle damage patients are returned to their normal activities quicker but also are at significantly reduced risk of problems such as dislocation and require fewer precautions post-operatively that are required following more traditional surgery such as raised lavatory seats and chairs, sleeping on their back etc. All these can be ignored and walking aids can be discarded after a few days. Similarly patients are able to return to driving when they are comfortable.
The prosthesis or implants used are traditional implants and have not been modified to accommodate this type of surgery. More importantly the surgery is performed with the patient supine which makes orientation of the components easier and also makes the use of an x-ray to position the components accurately possible which is not possible with the posterior approach.
One of the complications of hip surgery is DVT or Deep Vein Thrombosis. This can be reduced by several methods most important of which is early mobilisation of the patient. Because the patients get up on the same day or the next day after AMIS surgery the DVT rate is reduced. Also during surgery with the use of a special table the mechanical methods to reduce DVT such as calf pump stimulation continues throughout surgery which is the period when DVT is most likely to develop further reducing the clotting risk.