AMIS - A Medacta solution

The surgeon can access the hip joint via different paths, following a "conventional" surgical approach or a Minimally Invasive Surgical approach (MIS). True Minimally Invasive Surgery is characterised by the preservation of muscles and tendons encountered during surgery to the hip joint capsule and a shorter skin incision.

 AMIS is true Minimally Invasive Surgery

Other approaches advertised as minimally invasive (posterior, lateral, or double incision) are only reduced skin incision techniques and are associated with the same muscle and/or tendon injury as “conventional” approaches. AMIS does not cut muscles and does respect nerves
 


In fact, the anterior approach is the only technique which follows inter-muscular and inter-nervous planes to reduce the risk of injury to muscles, tendons, vessels and nerves. Possible muscular release is reduced to a minimum and in all cases is less significant than with other surgical approaches. For this reason AMIS is the ideal approach for atraumatic surgery which is fundamental for a fast recovery: AMIS will improve the quality of your life and hasten your recovery after a Total Hip Replacement.
The AMIS technique has decreased the incidence of complications when compared to “conventional” techniques. Your doctor will assist in providing more details.

Why an AMIS Total Hip Replacement?

The AMIS technique causes less surgical trauma than other techniques because NO MUSCLES ARE CUT[1,2], which aids in rapid recovery. AMIS can potentially provide you with the following benefits:

DECREASED POST-OPERATIVE PAIN [1,3]
In comparison with "conventional" surgical  techniques, the AMIS approach can reduce the post-operative pain as muscles are not cut.

SHORTER REHABILITATION [3,4]
Rehabilitation can usually start the day of the operation or the day after, subject to your doctor's approval, based on your post-operative conditions.
Standing up and walking with arm crutches can start immediately, with your doctor's authorisation. 

SHORTER HOSPITAL STAY [2,5]
The AMIS technique usually significantly reduces the duration of hospital stay.
Your surgeon may still recommend a longer stay depending on your post-operative condition.

SMALL SKIN SCAR [3]
With AMIS, the skin incision is often shorter than  with “conventional” surgery and therefore scar tissue is reduced.

FASTER RETURN TO DAILY ACTIVITIES [5,6,7]
The AMIS technique allows you to return to daily activities in a shorter time frame.

LESS BLOOD LOSS [2,3]
Preservation of muscles and vessels potentially reduces blood loss.
Transfusions are rare, blood clots in the legs (deep vein thrombosis) are potentially less likely.

REDUCED RISK OF DISLOCATION (separation of the hip ball and socket) [4,8]
As a result of  the AMIS technique the preservation of muscles significantly improves the stability of the hip. The risk of dislocation is minimal and the post-operative limitation of movements, usually prescribed in other techniques, is not necessary. The risk of dislocation is reduced because the anterior approach is performed from the front of your body and dislocation is mainly related to posterior hip structure damage.

PREVENTION OF LIMPING [9,10,11,12]
AMIS is characterised by a surgical technique that protects the various muscles, blood vessels and nerves encountered during exposure of the hip joint. Minimising muscle and nerve damage reduces the chance of limping.
You may drive when able to get in and out of the car comfortably, have excellent control of your legs  and are not taking pain medication.
Depending on your general condition and only with the approval of your surgeon, you may drive in 8 -10 days.

GOAL OF AMIS
The primary goal of AMIS Total Hip Replacement is to minimise harm to the muscles, blood vessels and nerves surrounding the joint.
The AMIS technique is the specifically designed method to achieve this goal.


 

REFERENCES
[1] Arthroplastie totale de hanche par voie antérieure et son évolution mini-invasive; F. Laude et al.; EMC; 2004, 44-667-B
[2] Single-incision anterior approach for total hip arthroplasty on an orthopaedic table; JM Matta et al; Clin Orthop Relat Res, 2005 Dec, (441): 115-24
[3] Minimally Invasive total hip arthroplasty: anterior approach; F. Rachbauer; Orthopäde, 2006 Jul;35(7):723-4, 726-9 
[4] Mini-incision anterior approach does not increase dislocation rate: a study of 1037 total hip Replacement; T Siguier et al; Clin Orthop Relat Res, 2004 Sep, (426): 164-73
[5] What‘s new in hip arthroplasty; MH Huo et al; JBJS Am; 2005 Sep, 87(9):2133-46
[6] Rapid Rehabilitation and recovery with minimally invasive total hip arthroplasty; RA Berger et al; Clin Orthop Relat Res, 2004, (429): 239-247
[7] The minimally invasive anterior approach to hip arthroplasty; RE Kennon et al; Orthopäde, 2006 Jul, 35 (7): 731-7
[8] Dislocation after hip hemiarthroplasty: anterior versus posterior capsular approach.; JB Bush et al; Orthopedics. 2007 Feb;30(2):138-44
[9] Muscular damage after total hip arthroplasty: conventional versus minimally invasive anterior approach.;  Dr Dora, Dr Kalberer; AOA 2008, Australia, Hobart
[10] Abductor Tendons and Muscles Assessed at MR Imaging after Total Hip Arthroplasty in Asymptomatic and Symptomatic Patients. C. Pfirmann et al., Radiology 2005, 235: 969-976.
[11] MR imaging of the abductor tendons and muscles after total hip replacement in asymptomatic and symptomatic patients. PD Dr. Dora, EFORT 2007
[12] Der anteriore Zugang für die minimal-invasive HTEP. C Dora; Leading Opinions Sept 2006, 1/2006