Authors

Dr Keran Sundaraj MBBS, MSc (Trauma), FRACS, FAOA

A periprosthetic fracture is a broken bone that occurs around an implant, such as a total hip replacement or a total knee replacement. Fractures around a hip replacement are more common, particularly around the femur (thigh bone). Frequently, surgery is required.

A fracture occurs most commonly years after a well functioning implant has been placed. Less commonly, a fracture may occur during the initial surgery as the bone is shaped to receive the implant.

Treatment of these fractures are challenging as patients are often older, have thinner bone, or other medical conditions.

In the hip, fractures most commonly occur around the stem of the metal component in the femur. In the knee, fractures most commonly occur above the femoral component.

Causes

Periprosthetic fractures most often occur during a fall, though they also occur in more high energy injuries such as a blow to the side or a motor vehicle accident. Risk factors for periprosthetic fractures include:

• Muscle weakness, poor vision, or poor balance leading to falls.

• Osteoporosis (weak bone).

• Loose implants - due to wear over a long period.

Treatment

Most commonly, surgery is required to fix a periprosthetic fracture. Factors to consider include:

• The type and location of the fracture.

• The quality of the remaining bone.

• Whether the implant is loose.

• A patients medical health.

Surgery may be:

• Open reduction and internal fixation

• Revision joint replacement

• A combination of both

If an implant is firmly fixed, the broken bone can be fixed with an open reduction and internal fixation (plates and screws). If the implant is loose, a new joint replacement may be required. This requires special implants that are longer than the original implants, and surgery can be complex. In some circumstances, bone graft may be necessary (either from the patient themselves or from donors).

Surgery will only be performed once it is medically safe to do so. Sometimes, medical doctors are asked to help optimise a patient before surgery. However, due to the complexity of the surgery and the equipment required, surgery may be delayed for several days to safely plan the procedure.

After surgery, the recovery period can be lengthy, and patients likely stay in the hospital for days to weeks. Pain relief and blood thinners to reduce the risk of clots are provided. Physiotherapists will help with getting patients back on their feet as soon as possible. The amount of weight allowed on the leg is determined case-by-case.

Possible Complications of Surgery

Complications following surgery for periprosthetic fractures can be serious. Common complications include:

• Infection

• Blood clots

• Dislocation

• Limb length inequality

• Poor fracture healing

• Repeat fracture

• Nerve or blood vessel injury

• Addition surgery

What to Discuss with Dr Sundaraj

• How long can I expect off work?

• When can I start driving?

• Do I need to be screened for osteoporosis (weak bones)?

• When can I start physiotherapy?

• What is the likely outcome from this treatment?

• When do I need to come back?