SEPTEMBER 1974 F I S I O T E R A P I E 5

TOTAL HIP REPLACEMENT
Dr. G . A . ROSSET 

M .B., B.Ch. (Witwatersrand), F.R.C.S. (Edin.),

Consulting Orthopaedic Surgeon, Medical School,

University of Witwatersrand and General Hospital, 

Johannesburg.

Degenerative arthritis of the hip joint, from  whatever 

cause, is treated conservatively during the initial phases 

of the disease. The principles of treatment are to 

diminish joint loading, improve stability and range of 

movement and medication to lessen pain and the co­

existent synovitis.

A

/  Reconstruction o f the hip joint is recommended when 

pain, stiffness, swelling and deformity lead to decreasing 

functional ability. Clincally, joint destruction is accom­

panied by loss o f stability and lim itation of movement.

Today the most satisfactory form  of reconstruction 

is by total replacement of the hip joint. Numerous 

designs are available but. in the Orthopaedic U nit of 

the Johannesburg Hospital preference is for the Charn- 

ley type o f low friction arthroplasty. This unit com ­

prises a plastic (high density poly-ethylene) acetabular 

cup articulating with a stainless steel fem oral com ­

ponent.

The operation, in the m ajority of cases, is reserved 

for elderly people. Consequently the risks are increased, 

necessitating particular care in pre-operative assessment 

and post-operative rehabilitation. Particular attention 

is paid to prevent complications such as deep vein 

thrombosis, pulm onary embolism, chest infection and 

heart failure.

\

0  Under general anaesthesia w ith the patient in the 

supine position a lateral approach is employed. The 

fascia lata is incised in the same plane, exposing the 

greater trochanter.

The greater trochanter is osteotomised and mobilised 

superiorly with the attached gluteus medius and short 

external rotator muscles. The advantages o f this step 

are that: (a) it gives a particularly good view of the 

hip joint and (b) it allows improvement of stability 

subsequently as, at the conclusion of the operation the 

trochanter is replaced more distally on the fem ur giving 

a greater mechanical advantage to the abductor muscles. 

A possible disadvantage is that firm bony union o f the 

trochanter takes approximately 1 2  weeks and detach­
ment during the rehabilitation period is a possibility. 

In practise this is a rare occurrence.

The hip is dislocated by flexing, adduoting and ex­

ternally rotating the leg. The head of the femur is

removed thus exposing the acetabulum in its entirety. 

The acetabulum is prepared by deepening and expand­

ing its margins with special reamers. A n y  residual 

cartilage is removed and key holes are drilled into the 

bony pelvis. The cup is subsequently accurately 

cemented into position. The importance of accurate 

positioning cannot be over emphasised; the cup must 

lie within the confines of the prepared acetabulum at 

an angle o f 45° to the horizontal plane and must be 

neither ante or retroverted. Poor position of the cup 

may lead to dislocation, instability and even loosening.

The femoral shaft is then reamed in order to accept 

the femoral prosthesis. 'Prior to cementing the femoral 

component into the shaft a trial reduction is performed 

to assess the range of movement. . Osteophytes which 

may impede movement and act as fulcra which assist 

dislocation are removed. The prosthesis is then 

accurately cemented into position paying particular 

attention to its position; no ante or retroversion being 

permitted. The cementing substance used for both com ­

ponents is poly methyl methacrylate which is basically 

an acrylic cement. Residual cement is removed and the 

new hip joint is now located.

The greater trochanter is re-attached to the shaft of 

the femur, being securely fixed with horizontal and 

vertical wires. The wound is closed in layers with 

suction drainage. These are im portant features of the 

operation not only to attain prim ary wound healing 

but particularly to prevent wound dehissance and 

haem atom a form ation which are particularly prone to 

turn septic. Infection w ould im ply total failure o f the 

operation.

The patient is carefully transferred to his bed m ain ­

taining the operated lim b  in abduction avoiding possible 

dislocation.

Blood loss during the operation amounts to approxim ­

ately 1 000 cc and this is replaced intra operatively by 
intra venous infusion. The operative time is kept to 

a m inim um , 60-80 minutes, in the knowledge that in­

fection rates are increased in prolonged procedures. 

Post operatively prophylactic intravenous antibiotics 

are employed for 48 hours and sub anti-coagulant doses 

of H eparin are administered for 5 days.

The importance of a good exposure is stressed, asso­

ciated with precise surgical technique, m in im um  operat­

ing time and above all attention to pre- and post-opera­

tive detail. A lthough the results of total hip replace­

ment are impressive there are still sufficient complica­

tions to suggest that the procedure should be reserved 

for suitable patients. The operation should be done by 

qualified surgeons. and the care and rehabilitation of 

such patients should be in the hands of nurses and 

physiotherapists who have been adequately exposed to 

the treatment of such cases.

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