Implant Fracture Analysis of the TFNA Proximal Femoral Nail

Abstract

Background: Mechanical failure of intramedullary nails is rare. This investigation was prompted by a series of cases of observed breakage of the recently introduced TFNA Proximal Femoral Nailing System (TFN [Trochanteric Fixation Nail]-Advanced; DePuy Synthes) in our region. Laboratory analysis and case data are presented, in contribution to post-market surveillance. Methods: Medical and imaging records from the 3 public tertiary orthopaedic trauma hospitals in Western Australia were reviewed. Relevant data of patients in whom breakage of the TFNA implant occurred between 2016 and 2018 were collected and analyzed. Laboratory review of retrieved implants was conducted at the Centre for Implant Technology and Retrieval Analysis (CITRA) in Western Australia. Results: A total of 16 cases of TFNA implant breakage were recorded and analyzed. The predominant OTA/AO fracture classification was 31A3 (12 cases, 75%). The reduction quality was good in 10 cases, acceptable in 4 cases, and poor in 2 cases. The mean time to failure (and standard deviation) was 5.0 ± 2.2 months (range, 2.2 to 9.8 months). The treatment modality for the breakage was revision nailing in 11 cases, arthroplasty in 3, and nonoperative management in 2. All nails broke at the proximal screw aperture, with 1 nail additionally breaking at the distal aperture. Of 8 patients treated with a second TFNA implant for nail breakage, 3 (38%) returned with breakage of the revision implant. Laboratory analysis of the broken nails demonstrated a unique fracture pattern, with a stepped propagation pathway. Conclusions: This study represents the largest series, to our knowledge, of proximal femoral nail breakages in the published English literature and is the first that we are aware of to involve laboratory analysis of the TFNA implant. Changes to the nail design and/or alloy may have contributed to the observed cases of breakage, and this study will be followed by an evaluation of breakage rates in comparison with those of previous generations of nailing systems. We advise close clinical and radiographic surveillance of patients with unstable hip fracture patterns who undergo osteosynthesis with use of a TFNA implant. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Treatment of Proximal Femur Fracture with a Newly Designed Nail: Trochanteric Fixation Nail-Advanced (TFNA)

“…Meanwhile, Lambers et al all six cases showed successful bone union during followup, and no implant fracture occurred during or after the six-month radiological assessment. 7) In seven cases of long nail use, there was no iatrogenic fracture or perforation of the distal anterior cortex at the distal femur, which results from a mismatch between femur and nail. The ROC of the newly designed TFNA is 1.0 m, and the curvature is increased compared to the conventional TFN, which has a ROC with a radius of 1.5 m. 4,5) Asian patients usually have more femoral bowing than do Western patients.…”

“…1). [4][5][6] Despite the many advantages of the new design characteristics of TFNA, Lamber et al 7) recently published a worrisome report of 16 cases of early implant breakage in the treatment of hip fracture patients. According to the data, implant failure mostly occurred in AO/OTA 31A3 fractures (reverse oblique type), and almost all implant fractures occurred at the proximal aperture.…”

“…According to the data, implant failure mostly occurred in AO/OTA 31A3 fractures (reverse oblique type), and almost all implant fractures occurred at the proximal aperture. 7) The purpose of this study is to report clinical outcomes and share our experiences regarding implant safety in hip fracture patients, with a minimum follow-up of six months.…”

Risk Factor of Breakage After Proximal Femoral Nail Antirotation in Intertrochanteric Fractures

“…The study suggested cautious surveillance of patients with unstable hip fracture who were treated with a TFNA implant. [20] They did not evaluate the CCD angle of the broken nails.…”

TFNA Implant Failure with Helical Blade Cut-out

“…Lamber et al found that TFNA nail breakage was seen mostly in unstable fracture patterns in their case series [ 15 ]. They also hypothesized that the reduced cross-sectional area of the TFNA at the level of the proximal screw aperture, changes in the alloy compared with its predecessors may be of importance in breakage of the TFNA at that site [ 15 ]. In our patient, since there was a cut-out of the helical blade from the femoral head, it was not possible to salvage the femoral head; therefore, we opted for bipolar hemiarthroplasty.…”