There are many different types of hip surgery available today, but these procedures are performed for essentially two main reasons: fracture or arthritis. The type of surgery performed is highly dependent upon the problem being treated and the anticipated outcome.
The type of hip fracture dictates the type of surgery performed, because of the blood supply to the femoral head. The two main types of hip fractures encountered are the femoral neck fracture and the intertrochanteric fracture.
Hip "Pinning" for Fracture
The term "hip pinning" is a rather loose one, in that one really never sees the use of "pins" to treat a hip fracture these days. The hardware has evolved dramatically over the years, and is very specific in use.
The traditional "hip pinning" procedure typically involves the use of a large bore/threaded screw that is surgically inserted into the femoral head, and is then attached to a metallic "side plate" that sits on the femoral shaft. These two pieces are locked together, and the plate is secured to the femur bone by way of several smaller threaded screws.
This combination locks the fracture in place, and allows the hip to move as one unit, instead of separate units, which causes significant pain and healing delays.
"In-Situ" Hip Fixation
The term "in-situ" literally means "as it sits," or "in its natural position." This concept applies to hip fractures that occur at the point where the femoral head joins the femoral neck. The surgery involves the insertion of approximately three hollow, or "cannulated," screws into the femoral head, thus immobilising the fracture and promoting proper healing.
One major concern regarding this procedure is that because the blood supply to the femoral head lies at the level of the junction of the head and femoral neck, the fracture must be what is called, "non displaced," or in near-anatomic position, to lessen the risks of damaged blood supply and femoral head death.
Intra-Medullary Nailing for Hip Fracture
A newer, more rigid and stable fixation construct is becoming increasingly popular as treatment for the intertrochanteric hip fracture. It is called the intra-medullary nail stabilisation procedure.
This procedure still involves the insertion of some type of large bore screw, or "blade" into the femoral head. This time, however, it is attached to a long metallic rod, or "nail" that is inserted into, and down the canal of the femur bone. The large screw and nail are locked together, and the opposite end of the nail is secured to the femur with a "locking" screw. This creates an extremely stable construct, which allows for early mobilisation of the patient, decreased blood loss from less invasive surgery, and pain reduction from stabilising the fracture.
This procedure is, as its name implies, hemi, or "half" of an arthroplasty. This procedure is usually performed as treatment for a hip fracture where there is no chance of salvaging the femoral head, due to irreparable damage to the blood supply, yet the patient's acetabulum (socket) is in good condition, and not in need of a prosthetic cup implant.
The fractured femoral head is removed, and sized for selection of a corresponding head implant. The femur bone canal is opened, and reamed to accommodate a prosthetic stem.
These parts are either cemented into place, or "press-fit" to stimulate bone in-growth into the prosthesis. It is a very stable combination, and allows for early mobilisation of the typical elderly patient to reduce the risks of other medical complications.
In some patients, typically ones with severe mental and physical handicaps such as cerebral palsy, hip fractures occur due to spastic movement of the leg(s), or even from positioning them in bed by caregivers. The typical candidate for a girdlestone procedure is one who does not walk at all, and will never walk. The procedure is done to relieve pain, and to improve quality of care.
The procedure involves the complete removal of the fractured head and proximal (nearest the hip) portion of the femur, to the extent it is involved. The end of the bone is covered with muscle to provide a cushion between the femur and the socket. This creates a form of "soft" joint or "false" joint, and cannot tolerate weight-bearing.