الفهرس 
Surgical anatomy of the hip JointOnly 14 pages are availabe for public view
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Abstract
Total hip arthroplasty is the most commonly performed adult reconstructive hip procedure.
Bone-saving hip arthroplasty using metaphyseal stems is gaining importance because the number of young patients is on the increase and hip resurfacing is not always indicated.
The rationale for short stems in cementless total hip arthroplasty (THA) is proximal load transfer and absence of distal fixation resulting in preserved femoral bone stock and avoidance of thigh pain.
An important benefit of a bone-sparing and preserving proximal femoral implant is the relative ease with which this can be converted to a conservative revision prosthesis, which need only invade the proximal diaphysis. This provides one extra step in the revision programme of a younger patient.
Also from the philosophy of the use of short stem total hip replacement is:
1) Stress-shielding reduction that made the peri-prosthetic bone content (as measured by DEXA scanning) was preserved at the baseline level or above throughout the follow-up period. That made the conservative implant should both conserve bone at the time of the operation and preserve bone in the longer term by providing more physiological loading.
2) The advantages claimed by the proponents of miniincision techniques include reduced blood loss and less soft tissue trauma, resulting in a faster recovery, a shorter hospital stay, and less postoperative pain than standard techniques.
Survival rates of these prostheses currently appear to be lower than for cementless standard stems. Nevertheless, these implants have the advantage of preserving proximal femoral medullary bone without the need to disrupt the diaphyseal marrow cavity.
In vitro studies of short-stemmed femoral implants have shown more initial migration than for conventional stems. The short implants stabilised when cortical contact was achieved or cancellous bone was compacted sufficiently.
Prerequisites for best performance are criteria of soft tissue (BMI) and bone stock should be suitable for the designe of implant.
There are many designs of short stem total hip replacement:
1) Cut prosthesis.
2) Fitmore prosthesis.
3) Mayo conservative hip.
4) Proxima prosthesis.
5) IPS hip.
6) Silent hip.
7) Metha hip prosthesis.
Practical considerations about surgical technique:
Rasp alignment in short stems can be difficult, because guidance provided by the proximal diaphyseal cavity as in longer stems is missing. For implants with a shoulder, the surgeon might have to open a gully into the cancellous greater trochanter. Otherwise, the implant deviates into varus position during impaction with increased risk of a calcar crack or intra-operative lateral femoral perforation.
Pre-operative analysis of a lateral hip film can be very helpful in order to anticipate potential difficulties in stem implantation, particularly if the surgeon intends to do a high femoral neck resection.
Anteversion of the neck and the physiological proximal femoral bend with its apex towards the posterior metaphysis complicate the initial orientation of the implant within the cancellous bone. The experienced surgeon will find the correct entry point far enough posteriorly within the femoral neck osteotomy in order to avoid mal-position, mainly when using a limited soft tissue approach
The main indications for the use of a short stem are osteoarthritis of sufficient severity of pain and loss of function, avascular necrosis and fracture neck femur in young active patient
The main limitations for the use of short stem are poor bone quality or bone shapes (Unsuitable bone shapes include severe coxa valga and coxa vara) and also can’t be used in revisions.