Catastrophic Failure After Open Reduction Internal Fixation of Femoral Neck Fractures With a Novel Locking Plate Implant
ABSTRACT : To determine if the use of a novel proximal femoral locking plate could reduce the incidence of femoral neck shortening and improve clinical outcomes after open reduction internal fixation (ORIF) for femoral neck fractures as compared with historical controls.
: Single surgeon, retrospective case-control study.
: Academic level I trauma center.
: Twenty-one femoral neck fractures treated with the posterolateral femoral locking plate (Synthes, Inc, Paoli, PA) were eligible for inclusion. Eighteen met inclusion/exclusion criteria with a mean follow-up of 16 months.
: ORIF of femoral neck fracture with the posterolateral femoral locking plate. This consists of a side plate with multiple locking screws directed into the femoral head at converging/diverging angles and a single shaft screw. Intraoperative compression was achieved with partially threaded screws before locking screw insertion.
: Maintenance of reduction was assessed by comparing immediate postoperative and final follow-up radiographs. Clinical outcome was assessed with Harris Hip Scores after 1 year. Complications and secondary operations were noted.
: Seven (36.8%) of 18 patients experienced catastrophic failure. Five of these patients required total hip replacement, whereas the remaining 2 died before further treatment. The remaining 11 patients (61.1%) achieved bony union; the average displacement of the center of the head did not differ when compared with historical controls (0.78 mm inferiorly, 1.62 mm medially, and 2.4 degrees of increased varus vs. 0.86 mm, 1.23 mm, and 0.6 degree). Complications in this group include 1 instance of screw fracture, 2 total hip replacements, and a peri-implant subtrochanteric femur fracture. The average patient age and proportion of displaced fractures did not differ between the historical control and experimental groups. Fracture displacement was strongly associated with catastrophic failure in the experimental group only. Average Harris Hip Scores was significantly worse compared with that of historical controls (67.9 vs. 84.7, P = 0.05).
: ORIF of femoral neck fractures using a locking plate construct yielded unacceptably poor outcomes in this patient population. We hypothesize that the stiffness of this construct prevents any fracture site micromotion, placing the mechanical burden on the implant, which can result in failure at the bone-screw interface or fatigue failure of the implant itself.
: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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ABSTRACT: Background Implants are used to stabilize femoral neck fractures to achieve successful fracture healing, but there is still a high rate of fracture non-unions. We compared micromotions in femurs with fractured femoral necks stabilized with three screws with or without a locking plate. We also investigated whether osteoporosis was associated with micromotion magnitudes, and explored the influence of implants on load distribution in the upper femur. Methods Twelve pairs of human cadaver femurs with femoral neck fractures (AO/OTA 31-B1) were allocated to fracture fixation by three locked screws or three individual screws. All femurs underwent dual energy X-ray absorptiometry. Physiological subject-specific axial load and torque was applied for 10,000 cycles. Micromotion of the head fragment was measured every 100 cycles with high-resolution optical motion detection. Load distribution was measured with strain-gauge rosettes attached to the lateral and medial proximal diaphysis. Findings The locking plate group showed reduced micromotion about the femoral neck axis (P = 0.035, effect size 0.62). No differences were found in valgus-varus or antegrade-retrograde rotations, or in the three translations. Micromotion magnitudes were not associated with osteoporosis. The overall micromotions of the upper femur and the load distribution in the proximal diaphysis were not influenced by fixation type. Interpretation The locking plate group showed increased resistance to shear forces compared with the screw group. This effect was not associated with a diagnosis of osteoporosis. The locking plate did not affect the load distribution in the proximal femur.Clinical biomechanics (Bristol, Avon) 05/2014; DOI:10.1016/j.clinbiomech.2014.03.006 · 1.88 Impact Factor
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ABSTRACT: Femoral neck fractures in young adults are difficult to treat. There are substantial gaps in our knowledge regarding treatment and prevention of young adult femoral neck fractures. Avoiding malunion or nonunion of these fractures after fixation remains a challenge. Currently available fixation techniques may allow for healing to occur, but in a shortened position, with negative consequences on gait mechanics and physical function. Osteonecrosis remains a problem, affecting up to half of patients who sustain femoral neck fractures. Achieving reliable healing may require a reconsideration of fracture fixation implants as well as biological methods to address metabolic, endocrine, and/or genetic abnormalities that may be present in the young adult femoral neck fracture patient. Also, prevention of low-energy femoral neck fractures (e.g. stress fracture) remains an area ripe for investigation. Copyright © 2014 Elsevier Ltd. All rights reserved.Injury 11/2014; 46(3). DOI:10.1016/j.injury.2014.11.015 · 2.46 Impact Factor
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ABSTRACT: Complications including nonunion and avascular necrosis are relatively common after internal fixation of a femoral neck fracture. Young patients are particularly impacted by these complications as salvage options often result in a suboptimal functional result. The quality of reduction appears to be of primary importance, however it is unknown if the choice of internal fixation affects the incidence of complications. In this paper we present the rationale and evidence for available internal fixation options. Currently there is insufficient evidence to recommend an optimal method of internal fixation, and this review demonstrates the need for high quality randomized, controlled trials to study this problem.Injury 12/2014; 85(3). DOI:10.1016/j.injury.2014.12.008 · 2.46 Impact Factor