Proxima hip operation perfomed by Dr.A.K.Venkatachalam of www.hipsurgery.in  associated with Chettinad health city

This bone sparing metal on metal hip prosthesis replicates normal size of the hip thus reducing incidence of dislocation and maximizing function.

The profile of the patient presenting for total hip replacement has changed. Pain and disability are no longer the only indications for surgery. The millennium patient, empowered with information, seeks surgical intervention to restore quality of life. Thus, even younger patients are presenting for total hip replacement. Conservative surgery embraces both soft issue sparing and bone conservation. If the surgeon is confident the hip he is going to use will outlast the patient he should use it. Otherwise he should consider the next operation and conserve bone.

Any implant that makes contact with the diaphyseal cortex or is ingrown distally will offload distally with consequent proximal stress protection. Bone conservation is achieved both by taking less bone at the time of surgery and by optimising the physiological loading of the proximal femur to preserve bone in the longer term.

Elegant biomechanical studies have shown that the PROXIMA is not a “fit and fill” prosthesis. Excellent axial and rotational stability can be achieved within the cancellous bone, and the implant is suspended in and moves in consort with the surrounding cancellous bone. This reduces the shear stresses at the fixation interface and optimizes load transfer in the metaphysis.

The technique for the insertion of the PROXIMA is ideally suited for minimally invasive surgical approaches. The “MicroHip” technique uses a section of the anterior Smith-Peterson approach. This is a truly internervous and intermuscular plane which provides excellent access to the hip joint. Minimal soft tissue disruption, together with bone preservation, makes PROXIMA a truly conservative option for the millennium patient.

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Indian Orthopedic surgeon performs first " Proxima" hip replacement in South India
December 05, 2006 Health News

(PRLEAP.COM) A 33 year old South Indian house wife suffering from a condition called Osteonecrosis; or avascular necrosis of both hips underwent a novel form of bone preserving hip replacement at the Bharathi Rajaa Specialty Hospital in Chennai, India this week.The technology has been introduced recently in India and Dr.A.K.Venkatachalam is the First Indian Surgeon to perform the operation in South India. The prosthesis implanted was the Proxima Hip Replacement, which is a very small prosthesis.

"The size of the implant is smaller and provides maximum direct contact with bone, besides increasing the longevity of the surgical procedure and eliminating thigh pain," says the surgeon. "It preserves more bone than traditional hip implant surgeries, but lesser than what hip resurfacing does.
Dr Francesco Saverio Santori an Italian Orthopaedic surgeon in association with a British Surgeon has designed this prosthesis and it has a ten year follow up.

Dr.Venkatachalam says that it is novel as the bone in the neck of the femur (Upper end of the thigh bone) is preserved. This type of hip replacement is a solution to selected group of patients who are not suitable for Surface hip replacement and in whom a total hip replacement is an option. This replacement surgery preserves bone stock, as the prosthesis is not implanted deep within the thighbone. It is a stemless stem. The bearing surfaces are made up of metal and this confirms enormous longevity to the prosthesis. It is also very stable as the diameter of the prosthesis is large and replicates the normal size of bone.

At present, minimally invasive surgery is the main trend of orthopaedic surgery and involves almost all its fields, joint replacement included. A total hip arthroplasty should be considered minimally invasive not just because it can be done through a small incision but it should preserve bone and only if bone resection is limited to pathologic tissues (conservative replacement) and the procedure is performed without major sacrifice of soft tissues. This last statement suggests that the term ;mini-incisions be substituted with ;mini-approaches meaning surgical approaches that respect the skin, but also fascia, tendons and muscles. Bone preservation may be obtained through proximal load, neck-retaining and resurfacing implants. Evaluating bone sacrifice both on the femoral side and on the acetabular side, neck-retaining arthroplasties seem to warrant the most balanced maintenance of bone tissue. Neck-preserving implants through a lateral or posterior mini-approach seem to be the most consolidated solution in minimally invasive total hip replacement.

It could be used in selective cases of hip arthritis, such as for people with good bone stock for whom resurfacing would not be suitable and a total hip replacement would be too radical.