Comparative study of intertrochanteric fracture fixation using proximal femoral nail with and without distal interlocking screws

Abstract

BACKGROUND Intertrochanteric (IT) fracture is one of the most common fractures seen in an orthopaedic practice. Proximal femoral nailing (PFN) is a common modality of fixing IT femur fracture. We retrospectively studied whether a PFN with two proximal lag screws can be done without distal interlocking screws in the 31-A1 and 31-A2 fracture patterns according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) guidelines for IT femur fractures. AIM To compare the outcomes of IT fractures (AO/OTA 31-A1 and 31-A2) treated by PFN with and without distal interlocking screws. METHODS We carried out a retrospective study of 140 patients in a tertiary care centre who had AO/OTA type 31-A1 and 31-A2 IT fractures. We divided the patients into two groups, in which one of the groups received distal interlocking screws (group 1) and the other group did not (group 2). The subjects were followed up for a mean period of 14 mo and assessed for radiological union time, fracture site collapse, mechanical stability of implant, and complications associated with the PFN with distal interlocking and without distal interlocking. Then, the results were compared. RESULTS PFN without distal interlocking screws has several advantages and gives better results over PFN with distal interlocking screws in the AO/OTA 31-A2 fracture pattern. However, similar results were observed in both groups with the fracture pattern AO/OTA 31-A1. In patients with fracture pattern AO/OTA 31-A2 treated by PFN without distal interlocking screws, there were minimal proximal lock-related complications and no risk of distal interlock-related complications. The operative time, IITV radiation time and time to radiological union were reduced. These patients also had better rotational alignment of the proximal femur, and the anatomy of the proximal femur was well maintained. It was also noted that in the cases where distal interlocking was performed, there was a gradual decrease in neck shaft angle, which led to varus collapse and failure of bone-implant construct in 21.40%. CONCLUSION In fracture pattern AO/OTA 31-A2, PFN without distal interlocking had better results and less complications than PFN with distal interlocking.

Kalça kırıklarının cerrahi tedavisinde kullanılan proksimal femoral çivilerinin distal kilitlenme tipinin radyolojik sonuçlarına etkisi

“…In a prospective comparative randomized study by Lil NA et al, the average fracture healing time was 8.8± 2.2 weeks in the locking group and (8.5±2.4 weeks) was in the unlocking group. There was no significant difference in the results 3 . Xing Li et al found the healing time as 14-16 weeks for patients having fracture pattern AO/OTA 31-A1 both in distal locked and unlocked patients 7 .…”

“…There are various complication occurrence rates in previous studies. Even so, it is seen that the results are not compatible with each other 3,15,18,19 . We did not have nail or locking screw breakage and the other results were similar to the previous studies.…”

“…Distal fractures close to the implant are complications that challenge surgeons. Some authors have reported that they have not seen any complications related to distal locking 3,11 , but there are also publications stating that implant-related complications occur, especially in the distal of the nail tips. Even so, no one examined this issue in detail.…”

“…Proximal femoral nails have become the most preferred implants in the treatment of these fractures 2 . Although it is a generally accepted concept that distal locking is necessary for the stability of proximal femoral nail (PFN) type implants used, in recent studies, it has been reported that dynamic locking is sufficient in stable type fractures and even locking is not required 3 . The issue of whether static distal locking with a single screw is safe has been investigated by some authors before.…”

“…Apart from its contribution to fracture healing, another issue that should be considered is that multiple drilling attempts and related damage to the bone cortex and muscle-soft tissue injuries can also be seen frequently in the distal locking step 5 . When the literature is examined, there are a few studies evaluating the self-locking implants without using screws 3 . Also, a small number of studies state that safe fracture fixation can be made without distal locking 6,7 .…”