Fracture after Total Hip Replacement
The higher physical demand of the elderly patient may also play a role in the increased incidence of periprosthetic fractures. The management of fractures after hip replacement is often surgical and may require the use of complex instruments or implants.
The majority of the periprosthetic fractures occur years after the surgery due to loosening of the implanted secondary to wear and tear or aseptic loosening. However, fractures may also occur during the surgery, especially in patients with metabolic bone disease such as osteoporosis.
Intraoperative acetabulum fractures
Intraoperative fractures occur during the surgery. Cementless fixation, not removing enough bone (under-reaming) before the impaction, metabolic bone disease such as osteoporosis, mal-formation of the acetabulum socket, any history of prior radiation therapy are all risk factors for intraoperative acetabulum fractures.
The fractures are evaluated intraoperative and if found to be stable, only observation is done along with protected weight-bearing. In case the fracture is found to be unstable, an acetabular component revision is done which may involve the use of jumbo cups or additional screws. In cases, where there is bone loss or extensive fracture, additional fixation may be necessary for the form of plates and screws along with bone graft.
Intraoperative femur fractures
Intraoperative femur fractures occur more often during revision total hip replacement rather than primary hip replacement. The fractures occur often during bone preparation of the femur for implant insertion. May occur as a result of a wrong technique, implants or instrument mismatch, or use of excessive force.
Patients with underlying bone metabolic disorders such as osteoporosis are also at an increased risk of intraoperative fractures. The management depends upon the level of fracture and the extent of the fracture. Usually, cables, wires, plates may be used to fix the fracture which is followed by re-insertion of the same implant or an implant with a longer stem.
Postoperative femur fractures
The fractures around the prosthetic joint occurring after the surgery are known as postoperative fractures. The postoperative fracture may occur in the early postoperative period or may occur years after the initial surgery.
Cementless hip arthroplasties are prone to fracture in the first 6 months of the surgery. Similar to intraoperative fractures, patients with diseases such as osteoporosis are at an increased risk of fracture. Compared to cementless fixation, cemented hip arthroplasties often fracture years after the surgery.
The postoperative fracture in the early postoperative period occurs as a result of stressors arising in the area of bone preparation for the implants. The fracture may be located near the upper part of the prosthesis. Cemented hip replacement often fractures below the lower end of the prosthesis.
The periprosthetic fractures occurring years after the initial surgery often occur as a result of aseptic loosening, or due to increased activity level of the patient.
The management of postoperative femur periprosthetic fracture depends upon the type and the extent of the fracture. Fractures of the greater and the lesser trochanter may be managed with the nonoperative treatment in the form of protected weight-bearing.
Displaced fractures may require the use of plates, wires, and screws. The implants may need to be revised along with fixation with other implants. The revised implants may have a longer stem or may be modified to accommodate the screws and plates.
The periprosthetic fractures after hip replacement often result in severe pain, disability, inability to bear weight, unequal leg length, or abnormal position of the leg. The symptoms are usually serious enough to warrant a visit to the ER and the patients are admitted to the hospital. Often patients may have multiple comorbid diseases that may require stabilization before the patients are fit for surgery.
The management largely depends upon the type and extent of the fracture and is usually surgical. The rehabilitation period following a periprosthetic fracture is usually longer compared to primary surgery. The patients may need to stay in the hospital longer. Rehabilitation usually involves therapy and pain management.
There may be potential complications of deep vein thrombosis, infection, blood loss, nerve injury, re-fracture, non-union of the fracture, leg length discrepancy, etc. Hip replacement surgeries are highly successful surgeries and the incidence of fracture is very low. Speak with your orthopedic surgeon regarding the risk of fracture and the management of periprosthetic fractures.