Fracture of the ipsilateral neck of the femur in shaft nailing. The role of CT in diagnosis

Ipsilateral femoral neck and shaft fractures: case series from a single Level-I trauma centre and review of literature

INTRODUCTION

Uncommon but increasingly diagnosed, ipsilateral femoral neck and shaft fracture represents a complex injury pattern with challenging management. The conundrum involves optimal diagnostic modality, timing of surgery, sequence of fixation, and the choice of implant.

METHODOLOGY

A retrospective review was conducted at a Level-I trauma centre to assess the outcome of concomitant femoral neck and shaft fractures managed with various implants and attempt to provide solutions to the aforementioned queries. The time between injury and definitive surgery, choice of implant, sequence of fixation, time to fracture union, and complications were documented and analyzed.

RESULTS

A total of 46 patients were included in the study wherein associated neck fracture was identified preoperatively in 93.5% of patients. In patients with isolated limb fractures, the mean time to surgery was 16.7 ± 5 h whereas patients with polytrauma witnessed an average delay of 4.6 days before fracture fixation. 72% of patients were managed by dual implants and in the remaining both the fractures were addressed using a single implant with no union time difference amongst implants. The mean time to the union for neck fracture was 21.7 weeks and 24.2 weeks for shaft femur fracture. 21.7% patients developed delayed union of fracture shaft femur and infection complicated 11% shaft fractures.

CONCLUSION

Although, 6% neck fractures were missed in the series, we advocate that careful pre/intra/post-operative fluoroscopic evaluation of the femoral neck along with a low threshold for a pre-operative CT scan remains the optimal diagnostic modality while avoiding universal employment of computed tomography (CT). With fracture union being unaffected by implant choice, authors suggest that anatomical fixation of the femoral neck is of paramount importance followed by restoration of the length, alignment and rotation of the femoral shaft, and the implant selection primarily depends on surgeon's experience and the pattern of injury.

Diagnosis and Management of Ipsilateral Femoral Neck and Shaft Fractures

Ipsilateral femoral neck and shaft fractures typically occur as a result of high-energy trauma in young adults. Up to 9% of femoral shaft fractures will have an associated femoral neck fracture. Awareness of this association and the use of a protocolized approach to diagnosis and management can help prevent missed injuries and the associated complications of displacement, nonunion, and osteonecrosis. The femoral neck fracture is often vertically oriented and either nondisplaced or minimally displaced, and thus, these fractures are frequently missed in the initial evaluation. Fixation of these combined injury patterns is challenging, and multiple treatment options exist. Treatment goals should include anatomic reduction and adequate fixation of the femoral neck fracture, as well as restoration of the length, alignment, and rotation of the femoral shaft fracture.

Special topic: Ipsilateral femoral neck and shaft fractures--does evidence give us the answer?

Ipsilateral fractures of the femoral neck and shaft are rare, high-energy injuries that typically occur in young polytrauma patients. The associated fracture of the neck is often vertical in nature and is more frequently non-displaced than in isolated femoral neck fractures. Historically the diagnosis of an associated femoral neck fracture was delayed or missed in approximately one third of cases. Studies have shown that detection can be significantly improved with the implementation of a protocolized approach to hip imaging in all patients with femoral shaft fractures. Prompt recognition of an associated femoral neck fracture allows for timely stabilization and may decrease the risks of non-union and avascular necrosis. In contrast, failure to recognize a non-displaced or minimally displaced associated neck fracture prior to fixation of the shaft can lead to displacement, a decrease in neck fixation options, a technically challenging secondary procedure and increased risk of long-term sequelae. A vast array of treatment strategies have been described for this combined injury. Published options range from spica casting to open reduction and internal fixation of both fractures and include almost all conceivable combinations in between. While timely surgical stabilization is now universally recommended for both shaft and neck, no consensus exists as to the most appropriate method of fixation for either fracture. Most authors recommend prompt, but not emergent, surgery with priority given to anatomic reduction and stabilization of the neck fracture by either closed or open methods. Fixation of the shaft fracture follows as patient condition allows. The rare nature of this injury makes it very challenging to study and most published series' are retrospective with very small sample sizes. In short, no scientificallycompelling study is available to definitively support any one implant choice or method of stabilzation over another for the treatment of associated fractures of the femoral neck and shaft.

Paediatric femoral shaft fractures: what are the concomitant injuries?

INTRODUCTION

Trauma remains a substantial cause of paediatric morbidity and mortality. Femur fractures are common in children, and frequently are the result of high-energy mechanisms of injury. A complete description of missed injuries in this population has not previously been described.

MATERIALS AND METHODS

A retrospective chart review of patients presenting to the Alberta Children's Hospital with femoral shaft fractures was performed. Associated injuries, and injuries with delayed diagnosis were recorded.

RESULTS

Twenty-percent of the patients suffered at least one other injury with their femur fracture. Six-percent of injuries had a delayed diagnosis, corresponding to three-percent of the patients reviewed.

CONCLUSION

There is a risk of missed injuries in the paediatric patient presenting with a femoral shaft fracture. Paediatric trauma teams and paediatric orthopaedic teams must be aware of this risk to help reduce the incidence of missed injuries. A tertiary trauma survey on children with paediatric femoral shaft fractures may help diagnose missed injuries.

False femoral neck fracture detected during shaft nailing: a Mach band effect

Femoral neck fractures are associated with femoral shaft fractures in 1% to 9% of cases. Undisplaced neck fractures are susceptible to displacement during shaft nailing. We report the case of a 57-year-old male patient in whom we performed standard intramedullary nailing for a femoral shaft fracture. In doing so, we identified a vertical radiolucent line at the femoral neck, which was thought to be further displacement of a hidden silent fracture or an iatrogenic fracture that developed during nail insertion. Consequently, we decided to switch to reconstructive femoral nailing. Postoperative hip imaging failed to show the femoral neck fracture that we saw in the operating room. Here, we discuss the aforementioned case and review the literature concerning this artifact.

Free vascularised fibular graft for neglected femoral neck fractures in young adults

Neglected femoral neck fractures in young adults pose a great challenge to orthopedic surgeons because of the high risks of nonunion and osteonecrosis. We attempted to determine whether free vascularised fibular grafting through an anterior approach could enhance bone union, improve hip function and reduce complications in the treatment of such fractures. Thirteen patients with neglected femoral neck fractures were treated with a free vascularised fibular graft through an anterior approach between 2004 and 2008. The mean age was 30.9 years (range, 17-47 years). The average delay between injury and operation was 6.7 months (range, 1.5-22 months). All 13 cases had ununited fractures but without osteonecrosis of the femoral head on plain radiographs before coming under our care. The average follow-up was 51.2 months (range, 36-75 months). All patients had fracture union within an average of 4.8 months (range, 3-9 months). Postoperatively, 9 patients had coxa vara of 10 to 20 degrees and leg discrepancy between 0.5 to 1.5 cm. One patient had coxa vara deformity of 25 degrees and 2-cm leg discrepancy. No patients developed osteonecrosis of the femoral head or donor-site morbidity. The mean Harris hip score improved from 55.5 points preoperatively to 84.8 points postoperatively (p<0.01). This procedure may be useful and safe in the treatment of neglected femoral neck fractures in young adults, but further studies with a large number of patients are needed.

Garden type I fractures myth or reality? A prospective study comparing CT scans with X-ray findings in Garden type I femoral neck fractures

The Garden type I femoral neck fracture is defined as an incomplete fracture of the neck of the femur as seen on the antero-posterior (AP) radiograph of the injured hip. The diagnosis of incomplete femoral neck fractures has decreased in recent years with the development of improved radiographic imaging. We hypothesized that incomplete femoral neck fractures seen on radiographs are in fact complete fractures on computed tomography (CT). The study aims to test this hypothesis by comparing CT scan images to X-ray findings in patients diagnosed with Garden type I femoral neck fractures. From January 2008 to October 2010, our management of femoral neck fractures included a CT scan of the injured hip for all Garden type I fractures. CT findings were reported by a musculoskeletal radiologist. A classification of the fracture was performed by an orthopedic surgeon. Eight hundred and twenty five femoral neck fractures were admitted during the study period. Seventeen of these fractures (2.1%) were considered incomplete based on radiographic evaluation. In 17 cases (100%), the CT scan demonstrated a complete fracture extending through the medial cortex. Subsequently, all 17 fractures were fixed with standard cannulated screw technique on a fracture table. Secondary displacement occurred in one patient prior to fixation. All fractures healed well and no avascular necrosis was noted. In summary, our study shows that incomplete femoral neck fractures identified on X-rays are actually complete fractures based on CT scans. If confirmed by a larger study population, our findings can simplify the Garden classification by eliminating an inaccurate subcategory. The clinical implications are that Garden type I fractures should all likely be fixed with cannulated screws and with an effort to prevent displacement during treatment.

The effects of transducer geometry on artifacts common to diagnostic bone imaging with conventional medical ultrasound

The portability, low cost, and non-ionizing radiation associated with medical ultrasound suggest that it has potential as a superior alternative to X-ray for bone imaging. However, when conventional ultrasound imaging systems are used for bone imaging, clinical acceptance is frequently limited by artifacts derived from reflections occurring away from the main axis of the acoustic beam. In this paper, the physical source of off-axis artifacts and the effect of transducer geometry on these artifacts are investigated in simulation and experimental studies. In agreement with diffraction theory, the sampled linear-array geometry possessed increased off-axis energy compared with single-element piston geometry, and therefore, exhibited greater levels of artifact signal. Simulation and experimental results demonstrated that the linear-array geometry exhibited increased artifact signal when the center frequency increased, when energy off-axis to the main acoustic beam (i.e., grating lobes) was perpendicularly incident upon off-axis surfaces, and when off-axis surfaces were specular rather than diffusive. The simulation model used to simulate specular reflections was validated experimentally and a correlation coefficient of 0.97 between experimental and simulated peak reflection contrast was observed. In ex vivo experiments, the piston geometry yielded 4 and 6.2 dB average contrast improvement compared with the linear array when imaging the spinous process and interlaminar space of an animal spine, respectively. This work indicates that off-axis reflections are a major source of ultrasound image artifacts, particularly in environments comprising specular reflecting (i.e., bone or bone-like) objects. Transducer geometries with reduced sensitivity to off-axis surface reflections, such as a piston transducer geometry, yield significant reductions in image artifact.

Management of femur shaft fractures in obese patients

Given the ongoing epidemic of obesity, femoral fracture management in the population affected by this condition is likely to become more frequent. Fracture treatment in obese patients poses a special challenge given greater difficulty in establishing an accurate diagnosis and confirming associated injuries. Adequate intraoperative positioning and obtaining accurate reduction and stable fixation may require special considerations. Obese patients have a high predisposition for complications such as compartment syndrome, nerve injuries, and pressure ulcers, and are at increased risk for medical complications given the high prevalence of comorbidities. A thorough understanding of the risks associated with obesity and the diagnostic and therapeutic challenges involved with femoral shaft fractures in this setting is paramount to achieve adequate results.

Iatrogenic femoral neck fracture during closed nailing of the femoral shaft fracture

BACKGROUND

Intramedullary nails have become a popular implant in the management of femoral shaft fractures. The occurrence of a femoral neck fracture after closed intramedullary nailing is an exceptional complication of this technique that has been rarely reported in the literature.

METHODS

We report a retrospective study to identify the possible causes that could produce a fracture of the femoral neck after nailing of the ipsilateral femur.

RESULTS

A total of four neck fractures were identified in a series of 494 femoral shaft nailing, all of them not visible on the initial plain films. In two cases, the nail entry point was located lateral to the tip of the greater trochanter. In the other two cases, the entry point was located too medial to the greater trochanter, violating the superoexternal cortex of the femoral neck.

CONCLUSION

The event of a femoral neck fracture during closed intramedullary nailing is an unusual complication that may be caused due to a technical mistake related to the location of the nail entry portal in the proximal femur.

Cephalomedullary nails in the management of ipsilateral neck and shaft fractures of the femur--one or two femoral neck screws?

This was a prospective study of 43 consecutive cases of combined ipsilateral femoral neck and shaft fractures treated with cephalomedullary nails. Sequential clinicoradiological evaluation of all high-energy femoral shaft fractures to detect associated ipsilateral neck fracture improved diagnosis. All but 1 of 35 cases included in the study achieved union of both fractures and excellent or good functional outcome. Mean Harris Hip Score at the last follow-up was 92+/-4 in single-neck screw configurations, and 94+/-3 for two-neck screw cephalomedullary nails which had better tip-apex distance. Mean sliding of the neck screw was 5+/-2mm with single-neck and 3+/-2mm with two-neck screw constructs. In six cases shortening was <1cm; 22 had delayed union of the shaft fracture, but only four of these needed additional surgery. Early aggressive fixation of both fractures using a cephalomedullary nail with the least possible surgical trauma is the key to success in these polytrauma cases.

[Management of ipsilateral femoral neck and shaft fractures]

PURPOSE

The combination of ipsilateral femoral neck and shaft fractures remains a treatment challenge in orthopedic surgery because both fracture types constitute separate entities and require specific treatment concepts.

MATERIAL AND METHODS

In a case control study, incidence, treatment strategies, and outcomes of this injury were analyzed. All patients with femoral fractures treated between 1 January 2001 and 31 July 2007 at a level I trauma center were included in the study.

RESULTS

Twenty-one out of 1,935 patients (1.1%) sustained 22 combined fractures of the femoral neck and shaft. Also considering the combination of femoral shaft fractures with fractures of the acetabulum and the distal femur (knee), the proportion of chain injuries of the femur was 3.1%. The rate of multiply injured patients in the group of patients with ipsilateral femoral neck and shaft fractures was 64%. The majority of the patients could be treated with a single implant for both fracture components. The leading fracture component was the femoral neck fracture in eight cases. All fractures consolidated after 4.7 months on average; one pseudarthrosis of the femoral neck was observed. All fractures were discovered in the course of primary diagnostic measures; in 73% of the patients, a computed tomography (CT) body scan was done. Fifty-nine percent of the patients with ipsilateral femoral neck and shaft fractures received primary definitive operative care. Complications included two torsional failures that needed correction and one case of postoperative infection that was easily treated.

CONCLUSION

Treatment of ipsilateral femoral neck and shaft fractures is still demanding, but diagnosis has improved with regular use of CT body scans in the management of multiply injured patients. Furthermore, possibilities for operative treatment have been advanced by the introduction of the long proximal femoral nail and the antegrade femoral nail, two implants supporting stabilization of these fracture entities.

Treatment of ipsilateral femoral neck and shaft fractures

OBJECTIVE

To investigate the clinical characteristics, treatment options and causes of misdiagnosis of ipsilateral femoral neck and shaft fractures.

METHODS

Among 20 patients with ipsilateral femoral neck and shaft fractures, 19 were treated operatively and 1 was treated conservatively. Sixteen cases of femoral shaft fractures were treated by open reduction and internal fixation with compressive plate, and 2 cases were treated with interlocking intramedullary nailing. Eighteen femoral neck fractures were treated with cannulated screws. Another patient was treated with proximal femoral nail to fix both the neck and shaft. Delayed diagnosis for femoral neck fractures occurred in 2 cases preoperatively.

RESULTS

A total of 19 patients were followed up. The follow up period ranged from 5 to 48 months with an average of 15 months. All the fractures were healed.

CONCLUSION

For case of femoral shaft fracture caused by high energy injury, an AP pelvic film should be routinely taken. Once the femoral neck fracture is recognized, operative reduction and fixation should be performed in time. Femoral neck and shaft fractures should be fixed separately.

Diagnosis of femoral neck fractures in patients with a femoral shaft fracture. Improvement with a standard protocol

BACKGROUND

An ipsilateral fracture of the femoral neck is seen in association with 1% to 9% of femoral shaft fractures, and 20% to 50% of these injuries are missed initially. Recognition of an associated femoral neck fracture prior to stabilization of the femoral shaft fracture is imperative to avoid or minimize complications of displacement and osteonecrosis.

METHODS

A protocol to look for a femoral neck fracture in all patients with a femoral shaft fracture was instituted at a single level-I trauma center. This protocol consisted of a dedicated anteroposterior internal rotation plain radiograph, a fine (2-mm) cut computed tomographic scan through the femoral neck, and an intraoperative fluoroscopic lateral radiograph prior to fixation as well as postoperative anteroposterior and lateral radiographs of the hip in the operating room prior to awakening the patient. A chi-square analysis comparing pre-protocol and post-protocol fracture prevalences was used to assess the relative risk of missing an associated femoral neck fracture.

RESULTS

Two hundred and sixty-eight consecutive patients with a femoral shaft fracture formed the basis of the study group. Of 254 who were followed for at least two months, sixteen were identified as having an associated ipsilateral femoral neck fracture with use of the protocol. Thirteen associated femoral neck fractures were identified before the patient entered the operating room for definitive fixation, and twelve of them were identified with the fine-cut computed tomographic scan. One fracture was identified intraoperatively. There was one iatrogenic fracture and one delayed diagnosis of a femoral neck fracture. With this protocol, we reduced the delay in diagnosis by 91% as compared with our experience in the year prior to the initiation of the protocol.

CONCLUSIONS

In the presence of a femoral shaft fracture, evaluation of the femoral neck with fine-cut computed tomography and dedicated internal rotation hip radiographs significantly improves the ability to diagnose an associated femoral neck fracture.

Low success rate of non-intervention after breakage of interlocking nails

We followed 12 patients with nailed femoral shaft fractures in which breakage of the static locked nail occurred during fracture treatment. Only two fractures united. The remaining ten fractures had to be treated with exchange nailing after a median of 10 (4-14) months. Nine fractures healed after a median of 5 (4-7) months and one was lost to follow-up. Although breakage of a proximal static reamed femoral locked nail may imitate the effect of dynamisation, the success rate is low. Early exchange nailing is a more successful option to achieve fracture union.

Noncontiguous fractures of the femoral neck, femoral shaft, and distal femur

BACKGROUND

Multifocal fractures of the femur are uncommon injuries and present unique management challenges. Combined ipsilateral fractures of the femoral shaft and femoral neck or the femoral shaft and distal femur have been described. The combination of noncontiguous ipsilateral femoral neck, femoral shaft, and distal femoral articular injuries, however, has not been described. The purposes of this report are to document the incidence and characteristics of this injury and to present a treatment rationale.

METHODS

This was a retrospective study conducted at a Level I trauma center.

RESULTS

Over a 5-year period, 1639 adult patients with femur fractures were definitively managed at the authors' institution. Five male and two female patients (average age, 43.3 years) sustained ipsilateral, noncontiguous fractures of the femoral neck, femoral shaft, and distal femoral articular surface (0.43%). All femoral neck fractures were vertically oriented. All distal femoral injuries were unicondylar. A variety of fixation methods were used, dependent on individual fracture characteristics. The femoral neck fractures were prioritized in all cases. Stabilization of the distal femoral articular surface was then performed before diaphyseal fixation in patients with sagittally oriented condylar fractures. Patients were followed for an average of 19.3 months. All fractures healed without the need for secondary procedures.

CONCLUSION

This injury constellation is rare. Open reduction and internal fixation of the displaced femoral neck fracture should be the primary focus of orthopedic management, followed by stable reduction and fixation of displaced distal femoral articular injuries. The diaphyseal fracture should be treated with a technique that does not jeopardize either the proximal or the distal fractures. Patients who are critically ill can be managed in a similar sequence over the course of several days, depending on their overall condition.

Entry point soft tissue damage in antegrade femoral nailing: a cadaver study

INTRODUCTION

Little attention is paid to insertion site morbidity associated with antegrade femoral nailing. However, residual peritrochanteric pain after nailing is not uncommon. Additionally, the end branches of the medial femoral circumflex artery (m.f.c.a.) supplying the femoral head are in close proximity to the insertion site of the nail, and the occurrence of avascular necrosis of the femoral epiphysis after nailing in adolescents is rather frequent.

OBJECTIVE

The aim of this study was to assess iatrogenic soft tissue injuries at the site of nail insertion.

MATERIALS AND METHODS

Nailing with a reamed AO universal femoral nail was performed on sixteen adult cadavers followed by dissection of the proximal part of the femur to assess possible damage to the soft tissues. Three entry portals were defined. (A) entry portal lateral to the junction of the neck and the greater trochanter; (B) entry portal at the base of the greater trochanter anterior to a line along the longitudinal axis of the femoral neck; and (C) entry portal at the base of the greater trochanter posterior to a line along the axis of the femoral neck (at the piriformis fossa).

RESULTS

In Group A, partial avulsion of the piriformis and the obturator internus tendon were present in four and in one of five specimens, respectively. Group B showed injuries to the piriformis tendon in two and to the gluteus minimus tendon in one of four cases. In Group C, partial avulsion of the piriformis, obturator internus, and obturator externus tendon were encountered in five, six, and two of seven specimens, respectively. Anterior branches of the ramus profundus of the m.f.c.a. within the synovial fold were damaged in all of these cases.

CONCLUSION

To select the best nail entry portal, the ease of nail insertion must be weighed against the resulting soft tissue damage at the site of insertion. The nail entry portal at the piriformis fossa, although geometrically ideal and most recommended, causes the most significant damage to muscle and tendons as well as to the blood supply to the femoral head. Therefore, even if reported only once, the occurrence of avascular necrosis of the femoral head after nailing in adults is a possible complication of this nail entry portal. The authors therefore prefer to avoid this entry portal in every case. The nail entry portal anterior to the longitudinal axis of the femoral neck, as in group B, although better with respect to the soft tissue damage, has the worst geometric and biomechanical disadvantages. The results of the current study favor the nail entry portal lateral at the greater trochanter as in Group A, which is equal to the entry portal B with respect to the soft tissue damage but allows introduction of the nail into the medullar cavity without difficulties.