Session III - Femur

Allograft Struts Are Not Required for the Treatment of Periprosthetic Femoral Shaft Fractures

William M. Ricci, MD; Joseph Borrelli, Jr., MD; Washington University School of Medicine, St. Louis, Missouri, USA

Purpose: Recent articles in the literature have shown that open reduction internal fixation of periprosthetic femur fractures with a combination of plate osteosynthesis and strut allograft provides good results. On the basis of these results, it has been suggested that allograft struts should be used routinely for such cases¹. Although plates and struts appear to be sufficient, it may be overstated to advocate use of both as a necessity. Furthermore, allograft has a finite risk of disease transmission that should be avoided whenever possible. Indirect fracture reduction techniques maximize the biologic potential for fracture repair and therefore may obviate the need for strut allografts during treatment of periprosthetic fractures around stable intramedullary implants. Results for patients treated with indirect fracture reduction techniques for periprosthetic femur fracture were investigated.

Methods: Included in this study were patients with periprosthetic femoral shaft fractures (OTA 32) about a stable intramedullary implant (Vancouver type B) treated with open reduction internal fixation by using indirect reduction techniques without the use of structural allograft. Twenty patients met the inclusion criteria. One died in the early postoperative period and two had inadequate follow-up. The remaining 17 patients (5 male, 12 female, with an average age of 75 years; range, 44 to 92) were studied prospectively. All fractures (13 OTA 32A, 4 OTA 32B) were closed. Internal fixation was with either a limited-contact dynamic compression plate (N = 10) or distal femoral locking plate (N = 7) (Synthes, Paoli, Pennsylvania). Cables (1.7 mm) were used to secure the plate around the intramedullary implant. Standard screw fixation was used elsewhere. Outcome measures included union (full weight-bearing without pain at the fracture site), alignment (satisfactory alignment defined as less than 5° of angulation), hardware failure, infection, and reoperation. Ambulatory status and scores on the Modified Lower Extremity Measure (LEM) were used for functional outcome assessment.

Results: The average follow-up was 14 months (range, 11 to 24). Eleven patients had previous hip arthroplasty (3 with revisions), 4 had intramedullary nails within the femoral canal for treatment of a previous fracture (all healed), and 2 had prior revision total knee replacement with long-stemmed femoral components. There were 10 cemented and 7 noncemented intramedullary implants. Fractures were at the tip of the implant in 12 cases, just distal in 4, and just proximal to the tip in 1.

All fractures healed after the index procedure. One patient had delayed union and had one cable fractured, but healed without other evidence of loosening or malalignment. All patients healed with satisfactory alignment. There were no infectious complications or reoperations. Thirteen of the 17 patients returned to their baseline ambulatory status, and 6 required additional assist devices. The average MLEM score was 63 (range, 40 to 95).

Conclusions/Significance: The results of this study support the use of open reduction internal fixation of periprosthetic femoral shaft fractures about stable intramedullary implants without the use of allograft struts. These results apply when indirect fracture reduction techniques that maximally preserve the local soft tissue envelope are used. As expected in a group of elderly patients with lower extremity fractures, the ability to return to preinjury ambulatory status was variable after healing of the periprosthetic femur fractures. The role of high-intensity rehabilitation of these patients is being investigated. Other functional outcome data (MLEM) collected in this study were not interpretable because of the lack of baseline scores in this group of patients, all of whom had previous surgery on the studied limb.

1. Haddad, F.S., et al. Periprosthetic Femoral Fractures Around Well-Fixed Implants: Use of Cortical Onlay Allografts with or without a Plate. JBJS, 2002, 84-A, 6: 945-950.