Orthopedics

Periprosthetic Fractures of the Femur

Michael Cross, MD; Mathias Bostrom, MD

Abstract

Treatment of periprosthetic femur fracture is based on fracture timing, implant stability, fracture pattern, and bone quality. Intraoperative fractures are usually stable; to prevent intraoperative fracture, careful preoperative planning and gentle operative techniques are essential. In managing unstable intraoperative and late postoperative periprosthetic fractures, the surgeon should be know the exact pattern of fracture, prosthesis stability, and bone quality. Loose prostheses should be revised and displaced fractures should be reduced and adequately fixed. These fractures typically occur in the peritrochanteric area, and their treatment is cerclage wiring or cables. Postoperative periprosthetic fractures are usually the result of trauma in the setting of loosening of the prosthesis and/or osteolysis. Periprosthetic femoral fractures are classified using the Vancouver classification, which is based on the location of the fracture, the amount of available proximal bone stock, and the stability of the stem. Correct classification of these fractures is important, as it helps to guide treatment.

T he incidence of periprosthetic femur fractures is increasing. These fractures pose a challenge for the orthopedist due to their complexity and associated poor outcomes. Intraoperative periprosthetic fractures are more common in uncemented total hip arthroplasty (THA; incidence, 3%-20%), especially during revisions, and are usually the result of technical error. These fractures typically occur in the peritrochanteric area, and their treatment is cerclage wiring or cables. However, distal fractures can also occur and are treated with a long-stem bypass of the fracture and secure fixation. Postoperative periprosthetic fractures are usually the result of trauma in the setting of loosening of the prosthesis and/or osteolysis.

Periprosthetic fractures of the femur are most commonly classified using the Vancouver classification, which is based on the location of the fracture, the amount of available proximal bone stock, and the stability of the stem.1 Correct classification of these fractures is important, as it helps to guide treatment. Vancouver type A fractures (4%) are peritrochanteric fractures (subtypes AL-Lesser and AG-Greater). Type B1 fractures (18.5%) occur around or just below the tip of the stem, in which the stem is well fixed. Type B2 fractures (44.6%) occur at or just below the tip of the stem, but do not have a well-fixed implant. Type B3 (36.9%) fractures occur at or just below the stem, in which the stem is not well fixed and there is poor bone stock in the proximal femur. Type C (9.3%) fractures occur well below the stem.

When considering treatment options, one must focus on maintaining prosthesis stability and encouraging union of the fracture. General principles that should be followed include revision of any loose stem, accurate fracture reduction, and secure fixation. Treatment is dependent on a number of variables, including the location of the fracture, stability of the prosthesis, quality of the bone stock, and patient age and medical condition (Figure).

Type A fractures are usually stable and minimally or nondisplaced, and thus are often treated nonoperatively. In cases of wide displacement, the usual treatment is open reduction and internal fixation (ORIF) using cerclage wires or cables to maintain abductor function. If a type A fracture is seen in massive osteolysis, early operative intervention should be considered. In addition, liner exchange should be considered if there is severe polyethylene wear at the time of fracture fixation.

A number of options exist for fixation of Vancouver B1 fractures, including wires or cables, plates and screws and/or cables, cortical onlay allograft, or a combination of these methods. However, it has been shown that metal plate and screw fixation (with or without proximal cables) is the most stable construct with regard to axial compression, lateral bending, and torsional loading.2 More specifically, it has…

Treatment of periprosthetic femur fracture is based on fracture timing, implant stability, fracture pattern, and bone quality. Intraoperative fractures are usually stable; to prevent intraoperative fracture, careful preoperative planning and gentle operative techniques are essential. In managing unstable intraoperative and late postoperative periprosthetic fractures, the surgeon should be know the exact pattern of fracture, prosthesis stability, and bone quality. Loose prostheses should be revised and displaced fractures should be reduced and adequately fixed. These fractures typically occur in the peritrochanteric area, and their treatment is cerclage wiring or cables. Postoperative periprosthetic fractures are usually the result of trauma in the setting of loosening of the prosthesis and/or osteolysis. Periprosthetic femoral fractures are classified using the Vancouver classification, which is based on the location of the fracture, the amount of available proximal bone stock, and the stability of the stem. Correct classification of these fractures is important, as it helps to guide treatment.

T he incidence of periprosthetic femur fractures is increasing. These fractures pose a challenge for the orthopedist due to their complexity and associated poor outcomes. Intraoperative periprosthetic fractures are more common in uncemented total hip arthroplasty (THA; incidence, 3%-20%), especially during revisions, and are usually the result of technical error. These fractures typically occur in the peritrochanteric area, and their treatment is cerclage wiring or cables. However, distal fractures can also occur and are treated with a long-stem bypass of the fracture and secure fixation. Postoperative periprosthetic fractures are usually the result of trauma in the setting of loosening of the prosthesis and/or osteolysis.

Classification

Periprosthetic fractures of the femur are most commonly classified using the Vancouver classification, which is based on the location of the fracture, the amount of available proximal bone stock, and the stability of the stem.1 Correct classification of these fractures is important, as it helps to guide treatment. Vancouver type A fractures (4%) are peritrochanteric fractures (subtypes AL-Lesser and AG-Greater). Type B1 fractures (18.5%) occur around or just below the tip of the stem, in which the stem is well fixed. Type B2 fractures (44.6%) occur at or just below the tip of the stem, but do not have a well-fixed implant. Type B3 (36.9%) fractures occur at or just below the stem, in which the stem is not well fixed and there is poor bone stock in the proximal femur. Type C (9.3%) fractures occur well below the stem.

Treatment

When considering treatment options, one must focus on maintaining prosthesis stability and encouraging union of the fracture. General principles that should be followed include revision of any loose stem, accurate fracture reduction, and secure fixation. Treatment is dependent on a number of variables, including the location of the fracture, stability of the prosthesis, quality of the bone stock, and patient age and medical condition (Figure).

Type A

Type A fractures are usually stable and minimally or nondisplaced, and thus are often treated nonoperatively. In cases of wide displacement, the usual treatment is open reduction and internal fixation (ORIF) using cerclage wires or cables to maintain abductor function. If a type A fracture is seen in massive osteolysis, early operative intervention should be considered. In addition, liner exchange should be considered if there is severe polyethylene wear at the time of fracture fixation.

Type B1

A number of options exist for fixation of Vancouver B1 fractures, including wires or cables, plates and screws and/or cables, cortical onlay allograft, or a combination of these methods. However, it has been shown that metal plate and screw fixation (with or without proximal cables) is the most stable construct with regard to axial compression, lateral bending, and torsional loading.2 More specifically, it has been shown that nonlocked plating, in conjunction with an allograft strut graft with cables and nonlocked screws, resulted in the highest stiffness and stability when compared to locked plating and nonlocked plating without a strut graft. However, demineralized bone matrix is not often needed.3,4 Long-term results will vary depending on a number of factors, including adequate fracture reduction, preservation of the periosteal blood supply, and adequate stress riser augmentation.

Type B2

Treatment of type B2 fractures requires revision arthroplasty in addition to ORIF. For an uncemented prosthesis, either an extensively coated, long-stem curved prosthesis or a fluted long-stem prosthesis can be used. Alternatively, a cemented prosthesis can also be used.

Type B3

Treatment options for type B3 fractures are directed by the fact that there is insufficient proximal bone stock to support the revision prosthesis. Thus, treatment involves either proximal femoral reconstruction using composite allograft or proximal femoral replacement. The decision between the 2 options will depend on the age of the patient, the functional class of the patient, and the severity of the bone defect.

Type C

Because type C fractures occur distal to the stem, treatment is independent of the arthroplasty. The usual treatment is to fix the fracture using plates and screws and/or cables, either with or without a strut allograft. However, in treating these fractures, one must be careful not to create new stress risers.

Conclusion

Periprosthetic fractures are challenging to treat. However, if one is able to accurately assess the stability of the stem, the amount of proximal bone stock, and the location of the fracture, the periprosthetic femur fracture treatment algorithm (Figure) can serve as an aid for guiding treatment.

References

  1. Duncan CP, Masri BA. Fractures of the femur after hip replacement. Instr Course Lect. 1995; (45):293-304.
  2. Dennis MG, Simon JA, Kummer FJ, Koval KJ, DiCesare PE. Fixation of periprosthetic femoral shaft factures occurring at the tip of the stem: a biomechanical study of 5 techniques. J Arthroplasty. 2000; 15(4):523-528.
  3. Ricci WM, Borrelli J Jr. Operative management of periprosthetic femur fractures in the elderly using biological fracture reduction and fixation techniques. Injury. 2007; (38 Suppl 3):S53-58.
  4. Wilson D, Frei H, Masri B, Oxland TR, Duncan CP. A biomechanical study comparing cortical onlay allograft struts and plates in the treatment of periprosthetic femoral fractures. Clin Biomech (Bristol, Avon). 2005; 20(1):70-76.

Authors

Drs Cross and Bostrom are from the Hospital for Special Surgery, New York, New York.

Drs Cross and Bostrom have no relevant financial relationships to disclose.

Presented at Current Concepts in Joint Replacement 2008 Winter Meeting; December 10-13, 2008; Orlando, Florida.

Correspondence should be addressed to: Mathias Bostrom, MD, 535 E 70th St, New York, NY 10021.

DOI: 10.3928/01477447-20090728-11

10.3928/01477447-20090728-11

Sign up to receive

Journal E-contents