Complications are a horrible aspect of any type of surgery. They have to be
recognized and if they happen, dealt with. They can be mild or devastating. They
can happen in spite of most stringent precautions and are upsetting for the
patient and the surgeon. Fortunately they are RARE!!! and most patients do fine.
All patients undergoing surgery, irrespective of type, are at risk of
complications. These include pneumonia, urinary tract infection, wound
infection, blood clots or DVT, etc. In addition, there are complications
specific to joint replacement. The more common ones are:
Dislocation: A hip replacement, both standard THR and resurfacing can slip out
of place. The incidence can be approximately 4% for standard THR and less for
resurfacing. The causes can be due to poor soft tissue control, non-compliance
to hip precautions and rarely to improper positioning of components. Treatment
is usually closed reduction under anesthesia and wearing a hip brace for six to
eight weeks. If dislocations become recurrent then a repeat surgical procedure
may be necessary.
Loosening/Component Failure: When an implant loosens, the bond between the
prosthesis and bone will become progressively weaker until the prosthesis is no
longer supported by the bone, and the bone and component will function as two
separate units rather than the bone and prosthesis composite functioning as one.
Loosening is most commonly caused by inflammation of the bone due to metal or
plastic particles. Rarely, loosening can be the result of infection or malposition of the components. The symptoms of loosening are progressively
increasing pain. In the end, the only resolution of a loose component is
surgical replacement of the loose component. Rarely, a joint replacement will
fail because of a material failure of the component itself; i.e., fracture of
the metal or plastic itself. This problem can only be corrected by surgically
replacing the failed component.
Deep Wound Infection: This is not a superficial tissue infection which can
usually be treated with antibiotics and occasionally debridement, but an
infection around the components themselves. Luckily this is rare, but when it
does happen, it needs to be aggressively treated. This involves surgically
removing the components and not putting anything back in. Intravenous
antibiotics are given for six to eight weeks, and if the infection has been
eradicated another attempt at joint replacement can be done and be successful 80
to 90% of the time.
Femoral Neck Fracture: In spite of a successful hip resurfacing, a fracture of
the femoral neck can occur. This is rare, 3% or less, but when it occurs, it is
necessary to surgically implant a total hip stem and apply a large steel ball to
the stem that matches the inner diameter of the implanted acetabular shell. This
preserves two of major advantages of resurfacing; a metal on metal articulating
surface, and a large diameter femoral head, providing increase stability.
Epilogue: Rarely, in spite of our best efforts, at the time of surgery,
technical factors make it impossible to perform a resurfacing. Also, the neck of
the femur may be inadvertently damaged, dramatically increasing the risk of
post-operative femoral neck fracture. In either of these situations we would
revert to a resurfacing acetabulum and a THR stem with a big metal ball. As a
last resort, a standard metal on metal, THR would be done.