Long-term outcomes of distal locking in extracapsular fractures treated with trochanteric Gamma3 nails

Background Few publications have assessed long-term results of distal locking of short endomedullary nails for extracapsular hip fracture. Virtually all of them focus on immediate differences. Criteria for the use of static or dynamic locking are unclear in most nailing systems, and use is advised in unstable fracture patterns or with risk of bell-clapper effect, but often influenced by the “orthopaedic school”. Materials and methods This is a historical cohort study on patients diagnosed and operated in 2014 and followed up until endpoint, considered as consolidation or major complication, plus evaluation of overall long-term survival. They were categorised as static distal locking (ST) or dynamic distal locking (DN). Both are comparable, except for all stable pre-operative classifications, Fracture Mobility Score (FMS) at discharge, and immediate post-operative loading, all of which were in favour of DN. Results Consolidation took place in > 95% of patients, with a non-statistically significant delay trend in ST. Less than 6% in both ST and DN had major complications, with no differences. Most cases suffered early cut-out. Significant fracture collapse was the most frequent minor complication. There were more statistically significant minor and total complications in ST. Infection, without differences, can precede cut-out. Lateral thigh pain was similar and could be related to back-out. In DN, 21.1% of cases were truly dynamised. We did not find differences in mobility or in long-term survival. Conclusions Any type of distal locking seems to be safe for consolidation, despite a slightly longer consolidation time in static locking. Early cut-out was the main complication, while others were very infrequent, which is an advantage over helical blade devices. There was a higher rate of minor and overall mechanical complications in ST, but infection and lateral thigh pain were similar. Most non-traumatic mechanical complications occurred around 5–6 weeks. About one in five of the DN truly dynamised, with all cases occurring before 8 weeks. Mobility until endpoint and overall long-term survival were not influenced by the locking mode used. Level of evidence Therapeutic study, level 2b.

An Uncommon Complication of Arteriovenous Fistula Following Intramedullary Nail Distal Locking – A Case Report

Introduction:An arterial pseudo aneurysm formation is an unusual complication following intramedullary nail distal locking screw insertion. During such surgical procedure, arterial laceration might damage the wall, allowing blood leakage into the soft- tissue surrounding. Only few records are available regarding such injuries. Case Report: A 19-year-old male diagnosed with femoral shaft fracture after a trauma event, was treated using Antegrade Long Intra-Medullary Nail with distal locking screw. Following post-operative serial blood count indicating a consistent decrease in his Haemoglobin levels, a Computed Tomography angiogram was performed and showed an arteriovenous fistula of the lateral superior geniculate artery. The artery was coiled, and haemoglobin levels were stabilized again. Conclusion: A distal interlocking screw should be carefully placed, including blunt dissection before the drilling and screw placement. In addition, blood counts were proved essential in routine. Keywords: Arteriovenous fistula, intramedullary nail distal locking, antegrade long intra-medullary nail.

A Finite Element Analysis and Cyclic Load Experiment on an Additional Transcortical-Type Hole Formed Around The Proximal Femoral Nail System’s Distal Locking Screw

Background A complication associated with the distal locking screw used in the proximal femoral nail (PFN) system is the formation of accidental additional holes. We hypothesized that an increase in stress around additional holes is a relevant factor contributing to fractures. This study aimed to evaluate stress changes in the cortical bone around additional screw holes using finite element analysis. Methods Proximal femoral nail PFN antirotation (PFNA)-II (Synthes, Solothurn, Switzerland) was inserted into a femur model. An additional 4.9-mm transcortical hole was made either anteriorly (anterior hole model) or posteriorly (posterior hole model) to the distal locking screw. Finite element analysis was used to calculate compression, tension, and load limits to investigate stress around additional holes with respect to the direction of screw penetration and degree of osteoporosis. The results were then compared with those of mechanical testing. A 31A-21 type intertrochanteric fracture was applied. As a control group, a model without additional holes (no-hole model) was developed. Repeated load-loading tests were performed on 10 model bones per model group. Results Tensile stress was significantly greater in the no-hole model when additional screw holes were present, and the anterior hole showed a higher maximum stress value than the posterior hole did, suggesting that the anterior hole was more susceptible to fracture. The change in tensile stress first appeared in the hole around the lateral cortical bone and proceeded to the medial side. Biomechanical testing showed that fractures around the distal locking screw occurred in 0 cases of the no-hole, 10 of anterior hole, and 9 of the posterior hole models. Conclusions During PFN surgery for intertrochanteric fracture, holes with distal locking screws fixed and removed at the anterior and posterior of the nail can be a risk factor for fractures in the surrounding area.

SHORT VS LONG PROXIMAL FEMORAL NAIL IN UNSTABLE INTERTROCHANTERIC FRACTURES OF FEMUR

BACKGROUND; The current methods of treatment of Inter Trochanteric fractures of femur are either DHS plating for a stable Intertrochanteric fracture or a Proximal Femoral Nail for an unstable IT fracture. There are increased surgical demands and complications associated with Unstable IT fractures. Fracture patterns like –Posteromedial large separate fragment, Basi cervical pattern, Reverse obliquity pattern, Displaced and/or avulsed greater trochanter, Lateral wall fractures pose challenges before operating surgeon. Failure to reduce the fracture before internal xation and failure to hold the reduction till denitive xation are the most frequent causes of poor results irrespective of the implant used for xation. . Present surgeon's usual preference is towards long PFN. There is an added advantage of increased stability due to splinting of the whole length of femur with the use of long PFN. However there are times where short PFN is preferred over long one when there is a mismatch of curvature between the nail and the femur. However, there is no pre-established treatment choice protocol in choosing long nail or short nail for trochanteric fractures, but many surgeons are reluctant to use short proximal femoral nails biased by literature showing more fracture rates with short PFN usage and with a belief that long nails can avoid stress risers in the diaphysis and make peri- prosthetic fracture rates acceptable. Some of the drawbacks of long PFN include increased operative duration, reaming of the medullary canal distally, unavailability of distal locking jig, leading to prolongation of distal locking time and exposing the surgical team to more radiation. Stacking the above facts the study tried to verify these in the practical scenario. The study was conducted at the department of orthopaedics Andhra Medical College Visakhapatnam Andhra Pradesh. Salvage procedures like Dimon osteotomy and Sarmiento osteotomy were not entertained in the present study.This effectively limits the study to cephalomedullary xation of un stable per trochanteric fractures with short and long Proximal Femoral Nail. METHODS: Study design: Hospital Based Comparative study. Study period: October 2017 to September 2019. Sample size: 30 (N=30, Short PFN-15, Long PFN-15) The study population was randomly divided into 2 groups with 15 patients in each group. Group S (odd): The patients who were operated with Short Proximal Femoral Nail. Group L (even): The patients who were operated with Long Proximal Femoral Nail. RESULTS Thirty cases of unstable inter-trochanteric fractures treated with reduction and internal xation with long or short proximal femoral nail were studied. In the present study minimum age was 29 years and maximum age was 75 years. Majority of the patients were between 51 to 70 years of age. Mean age for long PFN was 52.83 +/- 10.33 SD years, (Range 29-70). Mean age for short PFN was 58.16 +/- 13.94 SD years, (Range 35-75). In the present study males predominate females with a male to female ratio of 3:2. CONCLUSION We conclude that both short and long nails appear acceptable for use in unstable inter-trochanteric fractures. A reduction in operative duration and reduction in blood loss, which translates into a reduced blood transfusion requirement more importantly signicant reduction in image intensier exposures seen with short PFN makes it a surgeon friendly implant. We prefer long PFN for xation of unstable trochanteric fractures with osteoporosis so as to splint the whole femur.

Biomechanics of subtrochanteric fracture fixation using short cephalomedullary nails: A finite element analysis

A finite element analysis was performed to evaluate the stresses around nails and cortical bones in subtrochanteric (ST) fracture models fixed using short cephalomedullary nails (CMNs). A total 96 finite element models (FEMs) were simulated on a transverse ST fracture at eight levels with three different fracture gaps and two different distal locking screw configurations in both normal and osteoporotic bone. All FEMs were fixed using CMNs 200 mm in length. Two distal locking screws showed a wider safe range than 1 distal screw in both normal and osteoporotic bone at fracture gaps ≤ 3 mm. In normal bone FEMs fixed even with two distal locking screws, peak von Mises stresses (PVMSs) in cortical bone and nail constructs reached or exceeded 90% of the yield strength at fracture levels 50 mm and 0 and 50 mm, respectively, at all fracture gaps. In osteoporotic bone FEMs, PVMSs in cortical bone and nail constructs reached or exceeded 90% of the yield strength at fracture levels 50 mm and 0 and 50 mm, respectively, at a 1-mm fracture gap. However, at fracture gaps ≥ 2 mm, PVMSs in cortical bone reached or exceeded 90% of the yield strength at fracture levels ≥ 35 mm. PVMSs in nail showed the same results as 1-mm fracture gaps. PVMSs increased and safe range reduced, as the fracture gap increased. Short CMNs (200 mm in length) with two distal screws may be considered suitable for the fixation of ST transverse fractures at fracture levels 10 to 40 mm below the lesser trochanter in normal bone and 10 to 30 mm in osteoporotic bone, respectively, under the assumptions of anatomical reduction at fracture gap ≤ 3 mm. However, the fracture gap should be shortened to the minimum to reduce the risk of refracture and fixation failure, especially in osteoporotic fractures.

Comparison of fluoroscopy time in short and long cephalomedullary nailing for 31A2 intertrochanteric hip fractures

There is no study that has compared the radiation exposure during short (Short PFN) and long proximal femoral nailing (Long PFN) for 31A2 intertrochanteric hip fractures. The objective of the present study was to compare the radiation exposure time in short and long proximal femoral nail during the treatment of 31A2 intertrochanteric hip fractures. This prospective cohort study was carried out in a University teaching hospital. Sixty one consecutive patients with 31A2 intertrochanteric femur fracture treated with pro- ximal femoral nail were included in the study. The distal locking in the short PFN was performed using the locking zig and distal locking in the long PFN was performed using the free hand perfect circle technique. The same mobile image intensifier (Multimobil 5E, Siemens, Erlangen, Germany) was used in the entire study. The outcome measure was the fluoroscopy exposure time (seconds) which was measured directly from the image intensifier. Thirty patients underwent fixation with short PFN and 31 patients underwent fixation using long PFN. The mean fluoroscopy exposure time in short PFN cohort was 189.5 seconds ± 26 (range : 150-250 seconds) and the mean fluoroscopy exposure time in long PFN cohort was 283.4 seconds ± 43.8 (range : 200-400 seconds). The mean fluoroscopy exposure time was 93.9 seconds shorter in the short PFN cohort and this difference was statistically significant (p < 0.0001 ; 95% CI : 75.4 to 112.3). The radiation exposure to the operating team is significantly less during treatment with short PFN in 31A2 intertrochanteric fractures.

A Three-part Broken Interlocking Femoral Nail: Novel Technique of Removal and Review of Literature

A segmentally broken (three part) interlocking femoral nail with broken interlocking screw can be challenging to remove. We describe a novel technique for extraction of an unusual two level broken cannulated anterograde femoral nail to treat the delayed union with exchange nailing. This is the first reported case of a three-part broken intramedullary interlocking nail with broken distal locking screws, where the broken hardware was removed without opening the facture site or the knee. This technique is simple and does not require specialized equipment. The surgical technique and review of literature is presented.