Relationship between distal screws and femoral arteries in closed hip nailing on computed tomography angiography

Clinical observation and finite element analysis of femoral stable interlocking intramedullary nail in intertrochanteric fractures

PURPOSE

This study was designed to compare clinical outcomes of the femoral stable interlocking intramedullary nail (FSIIN) with proximal femoral nail anti-rotation (PFNA) for the treatment of intertrochanteric fractures (OTA 31A1 + A2).

METHODS

This study retrospectively analyzed a registered sample of 74 intertrochanteric fractures (OTA 31A1 + A2) surgically treated using FSIIN (n = 36) or PFNA (n = 38) from January 2015 to December 2021. The intra-operative variables (operation time, fluoroscopy time, intra-operative blood loss, length of incision) and fracture healing time were compared between the two groups in this study. Harris hip score (HHS) and visual analog scale (VAS) were used to evaluate the functional states. At the last follow-up, the incidence of related complications in patients was calculated. Eventually, the 3D finite element model was established to analyze the stress of FSIIN and PFNA.

RESULTS

The distribution of all basic characteristics was similar between the two groups (p > 0.05). The operation time, fluoroscopy time, intra-operative blood loss, and length of incision were significantly decreased in the FSIIN group (p < 0.001). The FSIIN group had a shorter fracture healing time than the PFNA group (p < 0.001). There is no significant difference between the two groups in the Harris and VAS (p > 0.05). The incidences of post-operative anaemia, electrolyte imbalance, varus malalignment, and thigh pain were significantly lower in FSIIN than in PFNA groups (all p < 0.05). The finite element results show that the stress shielding effect of FSIIN is smaller.

CONCLUSIONS

Our study revealed that FSIIN seemed to be superior to PFNA in the treatment of intertrochanteric fractures (OTA 31A1 + A2) due to less surgical damage and shorter fracture healing time.

Endovascular Management of Iatrogenic Arterial Injuries after Orthopedic Surgery of the Lower Limb

PURPOSE

To evaluate the safety and effectiveness of embolization, and to identify the contributory factors of failures in patients treated for iatrogenic arterial injuries after orthopedic surgery of the lower limb.

MATERIALS AND METHODS

In this retrospective study, data from patients treated from December 2008 to March 2022 for an arterial injury due to orthopedic surgery of the lower limb were analyzed from a single center. Demographic, clinical, and procedure-related data were collected. Perioperative and 30-day mortalities were estimated. Odds ratios and hazard ratios were calculated for several potential risk factors: age of >75 years, atherosclerosis, preexisting infection, urgency of surgery (trauma vs elective), previous surgery, multiple distant injuries, and multiple vascular supplies to the same injury.

RESULTS

Eighty-six procedures performed on 78 patients were included in the study. The rates of technical and clinical success were 100% and 92.3%, respectively. Six (7.7%) patients were retreated because of persistent bleeding. The perioperative mortality was 1.3%, and the 30-day mortality rate was 7.7%. The presence of multiple arterial supplies, multiple injuries, previous surgery, presence of atherosclerosis, or a preexisting musculoskeletal infection resulted in a higher risk of retreatment.

CONCLUSIONS

Embolization is safe and effective in the management of iatrogenic arterial injuries after orthopedic surgery. The number of involved vascular territories was the most critical factor in determining technical failure.

Identification of the lateral femoral safe zone for drilling during LISS plate fixation of distal femur fractures

BACKGROUND

The incidence of arterial injury associated with femoral fractures is approximately 1%. Lateral sub-muscular plate fixation is gaining popularity for the management of distal femoral fractures. The objective of this study was to assess the iatrogenic risk to the superficial femoral artery (SFA) during Less Invasive Stabilisation System (LISS) plate fixation of distal femoral fractures by analysing the range of distances and angles between LISS plate screws and the drilling line to the SFA.

MATERIALS AND METHODS

We identified all patients who underwent LISS plate fixation of distal femoral fractures between 2008 and 2018 in our level-1 trauma centre. Patients who underwent postoperative computed tomography for any reason were eligible for inclusion in the study. Twenty-five patients met the inclusion criteria. The sample comprised 10 male and 15 female patients with a mean age of 55 years. The most common fracture type was a supracondylar femur fracture (56%), followed by an intercondylar fracture (36%). A 13-hole LISS plate was the most common plate length used (44%). A consultant radiologist reviewed all scans to verify the visibility and marking of the SFA.

RESULTS

The median distance between the screw tip and the SFA was 21 mm (range, 8-65 mm). There was a negative correlation between the LISS plate hole number and the trajectory of drilling (Pearson coefficient: -0.87, p < 0.001). Using a linear regression model, the SFA was more likely to be in the line of drilling when the 6th to 10th holes in the LISS plate were used.

CONCLUSION

Extra care is needed when drilling into the LISS plate holes from the lateral to the medial direction in order to reduce the risk of iatrogenic injury to the SFA, especially in the high-risk plate zone where the artery can be close to the drilling line.

Evaluation of the positional relationship between femoral arteries and distal screws in the proximal femoral intramedullary nail for preventing iatrogenic vascular injury

BACKGROUND AND AIMS

Iatrogenic vascular injury associated with distal screw in the intramedullary nail for femoral trochanteric fracture is a rare but serious complication. This study aimed to investigate the positional relationship between distal screws and superficial (SFA), deep (DFA), and perforating femoral artery (PFA) using computed tomography (CT) angiography and to identify the risk factors of vascular injury.

PATIENTS AND METHODS

Thirty-eight patients (11 patients who underwent osteosynthesis with proximal femoral intramedullary nail and 27 healthy people) who underwent CT angiography were included. The distance from the great trochanter tip and insertion angle from posterior condylar axis (reference line) of the distal screws were measured, and the presence rates and distances from the femur of each artery within the insertion angle were investigated.

RESULTS

The distance from the great trochanter tip to the distal screw was 142.5 ± 8.8 mm. The insertion angle from the reference line was 27.3°±15° The measurement points were set at 130, 140, and 150 mm distal from the great trochanter tip, and the assumed insertion angle as 27°±15° Within this angle, the presence rates and distances were 50.8%/34.2 ± 7.0 mm (130 mm), 38.5%/34.3 ± 6.0 mm (140 mm), 30.8%/33.4 ± 6.0 mm (150 mm) in SFA; 12.3%/14.2 ± 3.3 mm (130 mm), 3.1%/13.1 ± 5.9 mm (140 mm), and 0% (150 mm) in DFA; and 0% (130-150 mm) in PFA. The presence rate of DFA increased at the posteromedial area in the thigh, and the distance from the femur became closer.

CONCLUSION

Within the angle that distal screws were likely to be inserted, the risk of DFA injury was the highest. Therefore, anatomical reduction of the femoral neck anteversion should be performed so that the distal screw will be inserted towards the anteromedial area in the thigh, and great attention should be paid not to over-drill the medial femoral cortex.

Distal locked or unlocked nailing for stable intertrochanteric fractures? A meta-analysis

BACKGROUND

To date, there are just several studies comparing distal locked nails with distal unlocked nails in treating intertrochanteric fractures. We report the first meta-analysis about this issue.

METHODS

Systematic search was conducted for studies in PubMed, Embase and Cochrane Library. Meta-analyses were performed regarding intra operative outcomes, complications and functional outcomes.

RESULTS

Pooled results showed insignificant difference between distal locking group and distal unlocking group in hip pain (relative risk (RR) 1.14, 95% confidence interval (CI) 0.59-2.19), distal tip fracture (RR 1.08, 95% CI 0.37-3.11), lag screw cut-out (RR 1.60, 95% CI 0.54-4.78), delayed or nonunion (RR 1.32, 95% CI 0.25-7.06), deep vein thrombosis (RR 1.06, 95% CI 0.23-4.84), wound infection (RR 0.58, 95% CI 0.28-1.22), Harris hip score (standard mean deviation (SMD) 0.03, 95% CI -0.15 to 0.21) and walking ability. However, significant difference was detected in operation time (SMD 0.77, 95% CI 0.36-1.17), fluoroscopy exposure time (SMD 1.02, 95% CI 0.52-1.52), blood loss (SMD 0.80, 95% CI 0.62-0.99) and total incision length (SMD 1.16, 95% CI 0.86-1.47). Result of trial sequential analysis indicated conclusive evidence.

CONCLUSION

Current evidence indicates that the distal locked intramedullary nails should not be recommended as routine choice for stable intertrochanteric fractures.

Late Presentation of an Iatrogenic Pseudoaneurysm of the Profunda Femoris Artery following Intramedullary Nailing

Introduction

Hip fractures are one of the most common osteoporotic fractures, and the incidence is expected to increase in the future. Vascular injury of the femoral vessels, although uncommon, is an intermittently reported complication in the treatment of proximal femoral fractures. This may be iatrogenic or less frequently as a result of the fracture itself. The profunda femoris artery is most commonly involved, probably because of its close relationship to the femur in the subtrochanteric region.

Case Presentation

We report a well-documented case of pseudoaneurysm of the profunda femoris artery after intramedullary nailing of an intertrochanteric femoral fracture. Arterial damage was due to overpenetration when drilling the distal locking hole. Because of the late presentation, pressure on the medial femoral diaphysis caused severe cortical scalloping. This resulted in an obvious radiographic image rarely reported before.

Conclusion

This case report illustrates the uncommon complication of pseudoaneurysm after intramedullary hip nailing. Because of the risk of potentially limb- and life-threatening complications, we advise careful drilling and placement of the distal locking screw. Excessive screw length should be avoided. The injured limb should be returned to the neutral position and lower-limb traction should be reduced before drilling the distal locking hole.

Risks to the Superior Gluteal Neurovascular Bundle During Iliosacral and Transsacral Screw Fixation: A Computed Tomogram Arteriography Study

OBJECTIVES

Iliosacral (IS) and transsacral (TS) screws are popular techniques to repair complicated injuries to the pelvis. The anatomy of the superior gluteal neurovasculature (SG NV bundle) is well described as running along the posterior ilium, providing innervation and perfusion to important abductor muscles. The method of pelvis fixation least likely to injure the SG NV bundle is unknown.

METHODS

Twenty uninjured patients with a contrasted computed tomogram of the pelvis and lower extremities (CTA) were evaluated. Starting points for an S1 IS screw and S1 and S2 TS screws were estimated on the "ghost" lateral CTA image for those pelvi with safe corridors (>9 mm diameter). The distance from the projected screw to the SG artery was measured. A distance of <3.65 mm (half of a 7.3-mm screw's diameter) was considered likely for NV bundle injury.

RESULTS

Of 40 pelvi CTAs (single sides), 10 pelvi (25%) were determined to be inappropriate for an S1 TS screw. The average distances from the screw starting point and the artery were 25.3 mm (±9.2) for S1 IS, 12.4 mm (±9.0) for S1 TS, and 23.5 mm (±10.7) for S2 TS screws, respectively. Ten S1 TS screws (25%) and no S1 IS or S2 TS screws were projected to have caused injury to the SG NV bundle (P < 0.001).

CONCLUSIONS

Inserting S1 IS and S2 TS screws put the SG NV anatomy at significantly less risk than S1 TS screws. This information may aid in choosing the "best" fixation option for patients with pelvic ring trauma requiring surgery.

The incidence of life threatening iatrogenic vessel injury following closed or open reduction and internal fixation of intertrochanteric femoral factures

AIM OF THE STUDY

Bleeding due to a vascular injury is a possible life-threatening complication of intertrochanteric femoral fracture internal fixation. Our goals were to find the current incidence of these events, and to describe the reasons, the presentation, and the treatment options.

METHOD

We conducted a retrospective record review of 1,469 patients who were operated upon at our institution due to AO31A femoral fractures from 2011 through 2015 and were treated with closed reduction and internal fixation.

RESULTS

Three patients were diagnosed with iatrogenic vascular bleeding, which constitute an incidence of 0.2%. The vascular injuries were detected as deep femoral artery bleeding adjacent to the distal locking screws. The patients were treated with ultrasound guided thrombin injection, endovascular coil embolization or with no endovascular intervention.

DISCUSSION

Vascular injuries are caused mainly by perforating a vessel while drilling the distal locking screw holes. A high level of suspicion and immediate imaging work-up are mandatory.

CONCLUSIONS

A vascular injury due to internal fixation of a proximal AO31A femoral fracture is a rare complication.

Relationship Between Femur and Femoral Arteries for Identifying Risk Factors for Vascular Injury

Background

This study aimed to identify risk factors for vascular injury in proximal femoral fracture through identifying frequency and distances between femur and femoral arteries with computed tomography angiography and 3-dimensional reconstruction.

Material/Methods

In a series of 400 participants, based on measurement results regarding the distribution of femoral arteries in the medial femur, the femoral portion covering that part was divided into levels A–E. The center region, margin region, and risky area in the medial femur were defined. The frequency of femoral arteries and interested shortest distance between the outer femur and superficial, deep, and perforating femoral arteries (SFAs, DFAs, and PFAs) in the center region, margin region, and risky area at each level were recorded.

Results

There were 173 males and 227 females (average age: 63.61±19.18 years) in this study. The starting point and end point for femoral arteries in the medial femur were from 22.55±4.23% to 54.56±8.39% of the whole femur. The femoral arteries in the medial femur mainly were distributed at levels B (88.2%), C (65.9%), and D (40.6%). The femoral arteries in center regions in the risky area, most of which were DFAs and PFAs, were mainly concentrated at levels B (26.93%) and C (11.81%).

Conclusions

The mid-shaft level was the most risky level, and the DFAs and PFAs were easier to injure than the SFAs when performing internal fixation of proximal femoral fracture. We recommended that great attention be paid to drill and screw insertion around the mid-shaft level for prevention of iatrogenic vascular injury.

Imaging Evaluation of the Safe Region for Distal Locking Screw of Proximal Femoral Nail Anti-Rotation in Patients with Proximal Femoral Fracture

Background

Proximal femoral nail anti-rotation (PFNA) is a standard femoral intertrochanteric fracture operation. Iatrogenic vascular injury, although uncommon, is a reported complication of PFNA surgery as well as a complication of hip fracture surgery. This study aimed to compare the safety and best use of the distal locking screw in 170 mm PFNA and 240 mm PFNA devices, and to determine the safe region for placement of the distal locking screw in PFNA surgery.

Material/Methods

A retrospective analysis of 100 patients with 170 mm PFNA and 80 patients with 240 mm PFNA were retrospectively analyzed. Two levels of PFNA distal locking screws were equally divided into three planes: I, II, III, for 170 mm PFNA devices and i, ii, iii for the 240 mm PRNA devices. The medial half of the femur was equally divided into eight regions: A to H. The distance between the outer femur and the superficial, the deep and the perforating femoral arteries (SFAs, DFAs, and PFAs), and angles between the reference line and the connection line between the femur center to each artery were measured.

Results

SFAs and DFAs but not PFAs were found in risky or hazardous regions, and DFAs were obviously closer to the femur than SFAs and PFAs at the same level. In the region within 10 mm of the femur, no SFAs were found. The short nails (170 mm PFNA-II devices) were the closest to the DFAs region, indicating that the 170 mm PFNA-II nails are most likely to cause special vessel injury. The short nails were relatively more distant from the SFAs, which were located posteriorly to the long nails (240 mm PFNA-II).

Conclusions

The distal locking screw of the 170 mm PFNA device was more prone to damage the femoral deep artery when the two types of PFNA devices are compared in patients who were candidates for both types of devices.

Postoperative Computed Tomography for Articular Fractures: A Systematic Review

OBJECTIVES

To determine the current published patterns of computed tomography (CT) use postoperatively in peri-articular fractures and identify those populations whereby postoperative CT changes management or results in better clinical outcomes.

DATA SOURCES

Systematic review of MEDLINE and Cochrane using a combination of key words, including fracture fixation, fracture healing, and computed tomography. The final update search was performed on May 20, 2015. The search was limited to English language publications of human studies from the past 20 years.

STUDY SELECTION

Eligible studies enrolled internally fixed peri-articular fractures in adults imaged routinely with postoperative CT. Facial and spinal fracture studies were excluded.

DATA EXTRACTION

One thousand five hundred thirty-seven articles were identified using the search strategy. One thousand two hundred ninty-seven articles were excluded by title. One hundred eighty-three studies were excluded by abstract. Fifty-seven full text articles were assessed for eligibility, 31 studies were eligible for study inclusion.

DATA SYNTHESIS

There was no intention to perform combined statistical analysis in the form of a meta-analysis as disparity was anticipated between study populations, interventions, and outcome measures. Routine CT use postoperatively in peri-articular fractures is limited to countries within the developed world, predominantly imaging the lower limb. Only 5 studies detailed postoperative CT leading to a change in patient management; within this pool, only 8 of the 361 individual patients received management changes due to CT scan findings.

CONCLUSIONS

Use of postoperative CT in peri-articular fracture fixation has been demonstrated with minimal evidence, this leads to improved clinical outcomes. Based on available literature, postoperative CT scan use is questionable without convincing evidence of benefit. More research is required to identify selected patients who benefit from postoperative CT imaging.

LEVEL OF EVIDENCE

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Rupture of the Deep Femoral Artery during Proximal Femoral Nailing Following an Intertrochanteric Fracture: A Case Report

Recently, we experienced a case where the diagnosis and management of a deep femoral artery rupture was delayed. This vascular complication occurred during the insertion of a distal interlocking screw of a proximal femoral nail for the fixation of an intertrochanteric femur fracture. A 79-year-old male patient was diagnosed with a right intertrochanteric fracture after a fall. We fixed the fracture with a proximal femoral nail (Zimmer® Natural Nail™ System). One day after the procedure, the patient complained of pain and swelling on the anteromedial side of his middle thigh followed by hypotension, anemia and prolonged thigh swelling. Computed tomography angiography was performed 7 days after the procedure. We found a pseudoaneurysm of the perforating artery caused by injury to the deep femoral artery and an intramuscular hematoma in the anterior thigh muscle. We successfully treated the pseudoaneurysm using coil embolization. Throughout the management of intertrochanteric femoral fractures, it is important to be aware and monitor signs and symptoms related to the possibility of blood vessel damage. When a patient presents with swelling and pain on the middle thigh and/or unexplained anemia postoperatively, the possibility that these symptoms are caused by an injury to the femoral artery must be considered.

Safe zone for the superficial femoral artery demonstrated on computed tomography angiography

INTRODUCTION

Internal or external fixation of the femur is common following trauma. Neurovascular structures around the shaft of the femur are at risk, particularly the superficial femoral artery (SFA). Damage to this structure, when it is medial to the femur, can occur during the lateral approach, when drills, pins or screws are inserted. This anatomical study aims to delineate a safe zone for operative intervention to the shaft of the femur with respect to the SFA, and describe the relationship between this zone and the width and length of the femur.

MATERIALS AND METHODS

41 limbs from 22 patients were examined using Computed Tomography Angiography to determine the relationship between the SFA and the medial shaft of the femur. The danger zone where the SFA lies medial to the shaft of the femur in the sagittal plane was identified and measured, and the width and length of the femur were measured for reference points.

RESULTS

The SFA begins anterior to the shaft of the femur proximally and passes posteriorly, crossing the shaft of the femur in the sagittal plane at points 239.6±39.8mm and 172.5±40.9mm proximal to the adductor tubercle (AT). The width of the femur correlates to the inferior crossing point of the SFA on the femur with a mean ratio of 1:2.05, p=0.000, the length of the femur correlates to the mid crossing point of the SFA on the femur with a ratio of 2.00:1, p=0.000.

CONCLUSIONS

There is a safe zone along the medial shaft of the femur, which can be estimated intraoperatively using anatomical reference points.

Proximal femoral fractures and vascular injuries in adults: Incidence, aetiology and outcomes

INTRODUCTION

Vascular injuries (VI) presenting during internal fixation (IF) of proximal femoral fractures (PFF) are potentially limb- and life-threatening. The purpose of this systematic review of the literature is to report on their incidence, associated complications and to give special emphasis in their prevention.

MATERIALS AND METHODS

A comprehensive review of the literature was undertaken using the PRISMA guidelines with no language restriction. Case reports of VIPFF-IF and series of PFF-IF with cases of VI published between inception of journals to March 2015 were eligible for inclusion. Relevant information was divided in two parts. Part I included the analysis of cases of VIPFF-IF, with the objective of establishing the frequency of injury of each vessel, the types and mechanisms of injury, the diagnostic and therapeutic modalities, and the outcomes. Part II analysed series of PFF-IF, which included case(s) of VI for assessing the incidence of VIPFF-IF.

RESULTS

Overall 160 articles with 182 cases of VIPFF-IF met the inclusion criteria. The injuries to extrapelvic vessels prevailed over those of intrapelvic vessels. There was a higher frequency of injury to the deep femoral artery and its branches in extrapelvic vessels and of external iliac artery and vein in intrapelvic vessels. The types of injury were: compression, intimal flap tear, disruption of the intimal layer with thrombosis, laceration with haemorrhage, and puncture or progressive erosion leading to a pseudoaneurysm (PSA) or arteriovenous fistula (AVF), with high prevalence for PSA, followed by lacerations. PSAs were more frequent in extrapelvic lesions and lacerations in the intrapelvic vessels. There were 7 non-iatrogenic injuries, produced by a displaced lesser trochanter fragment or other bone fragments, and 175 iatrogenic injuries (96.15%). The intrapelvic intraoperative protrusion of instruments or implants, or the post-operative migration of implants produced the injuries of intrapelvic vessels. For iatrogenic injuries of extrapelvic vessels the prevalent mechanism was a displaced lesser trochanter fragment, either intra- or postoperatively, followed by injuries by an overshot drill bit or a protruding screw; several other mechanisms completed the list. The clinical and radiological investigations were similar to those of VI elsewhere. VI occurred either at the time of fracture, during surgery or after it, early or late, weeks, months or even years after IF. The diagnostic and therapeutic modalities were most diverse, and the incidence of morbidity and mortality was 18.06%. The overall incidence of VIPFF-IF was 0.49%.

CONCLUSION

The incidence of VIPFF-IF is low, though it will probably rise because of the increasing frequency of PFF. With few exceptions, these injuries, which are potentially limb and life-threatening, are iatrogenic, resulting of errors in IF, with different types of lesions to intra- and extrapelvic vessels running in close proximity to the bone. Although the surgeon should bear in mind this possibility and achieve early diagnosis and prompt accurate treatment, there is no consensus as to what is the best diagnostic or therapeutic modality. A precise diagnosis of the preoperative vascular status of the limb, monitoring of the displacement of the lesser trochanter fragment, careful and gentle reduction of the fracture, and precise handling of instruments and implant selection and placement during IF, are factors to consider in order to prevent this complication, which should never be underestimated.