Superior gluteal artery pseudoaneurysm following intramedullary nailing of an atypical femoral fracture

Abstract

A 79-year-old woman with a history of osteoporosis treated with alendronate presented to the orthopaedic clinic with persistent left hip pain. X-ray and bone scan revealed an atypical femoral fracture associated with bisphosphonate use. The fracture was repaired with antegrade femoral intramedullary fixation. Her postoperative course was complicated by acute blood loss anaemia requiring several packed red blood cell transfusions and progressive thigh ecchymosis. CT angiography demonstrated extravasation of contrast from the superior gluteal artery (SGA). Subsequent angiography revealed an SGA pseudoaneurysm above the intramedullary nail, which was coil embolised. Iatrogenic SGA injury secondary to femoral intramedullary fixation is a rare complication, with only one previous case reported in the literature. Therefore, successful identification of the injury required attention to patient reported symptoms, neurovascular examinations and laboratory values to determine the cause of the patient’s postoperative anaemia. The patient made a full recovery and did not have any long-term adverse effects following the embolisation.

Background

Postoperative haemorrhage due to superior gluteal artery (SGA) injury is a rare but potentially life-threatening complication after operative treatment of femur fractures with intramedullary devices. To our knowledge, there has been only one reported case of iatrogenic SGA injury following intramedullary femoral nailing reported in the literature.¹ If not recognised in a timely manner, the consequences of this injury may be severe. Potential sequelae include haemorrhagic shock, gluteal compartment syndrome, muscle necrosis and aneurysm formation.^2–4

We report the presentation, diagnosis and management of postoperative acute blood loss anaemia due to iatrogenic SGA injury during intramedullary fixation of an atypical femur fracture. Meticulous attention to patient reported symptoms, neurovascular examinations and laboratory values was necessary to determine the cause of the patient’s acute onset postoperative anaemia. This case demonstrates the importance of maintaining a high suspicion for vascular injury when a patient presents with acute anaemia in the postoperative setting, despite no evidence of intraoperative vascular injury.

Case presentation

A 79-year-old woman with a medical history of osteoporosis treated with alendronate presented to the outpatient orthopaedic clinic with a chief complaint of increasing left hip pain with ambulation. The pain radiated to her anterior thigh and knee and was described as ‘feeling like the leg would break if she stepped on a curb’. Physical examination of the left hip was unremarkable for groin and greater trochanteric pain. In addition, the patient complained of no back pain or tenderness and the pain was not aggravated with a straight leg raise. Initial workup included X-rays of the hip, pelvis and femur, which were unremarkable with the exception of mild bilateral hip and sacroiliac joint arthritis. Therefore, the patient was initially managed conservatively with anti-inflammatory medications, an assistive walking cane and vitamin D supplementation. Due to persistent symptoms 6 weeks later, a bone scan and repeat X-rays were obtained to rule out a stress fracture. The images at that time demonstrated proximal femur lateral cortical thickening and an incomplete fracture, consistent with a bisphosphonate associated atypical femur fracture (figure 1). The patient was subsequently admitted to the hospital for intramedullary nailing of the left femur.

Figure 1.

(A) X-ray image of the left femur demonstrating an incomplete fracture of the lateral cortex. (B) Bone scan of the left femur demonstrating a focus of increased radiotracer uptake along the lateral surface, consistent with a stress fracture.

The patient was taken to the operating room and positioned using a standard fracture table. An incision proximal to the greater trochanter was made and the iliotibial (IT) band was split in line with its fibres. Blunt dissection was carried down to the level of the greater trochanter and the starting point for a trochanteric nail was obtained with a 3.2 mm guide pin. The pin was advanced to the level of the lesser trochanter and then a standard technique was used to ream with flexible reamers to 11.5 mm. A 10×380 mm intramedullary nail (TFNA, Depuy Synthes) with a 95 mm cephalomedullary screw was placed and locked with two distal screws (figure 2). Estimated blood loss was 200 mL.

Figure 2.

Intraoperative X-ray image of the left hip demonstrating a properly positioned 10×380 mm intramedullary nail with a 95 mm cephalomedullary screw.

In the post-anaesthesia care unit, the patient experienced an episode of symptomatic bradycardia and hypotension with a systolic blood pressure as low as 50 mm Hg that required treatment with crystalloid fluids, atropine and norepinephrine. An extensive cardiac workup including chest radiographs, electrocardiography, a transthoracic echocardiogram and serum troponins was negative. The patient’s haemoglobin value was 111 g/L (reference range 120–155) at this time. On postoperative day 1, the patient received two units of packed red blood cells (pRBCs) following a decrease of haemoglobin to 62 g/L with continued symptomatic bradycardia and hypotension with a blood pressure of 60/40 mm Hg. Her haemoglobin increased to 81 g/L after the transfusion. On postoperative day 2, the patient’s haemoglobin improved to 88 g/L and on physical examination there was no evidence of gluteal or thigh haematoma and her gluteal compartment was soft. So, the decision was made to observe the patient since she was clinically improving. However, on postoperative day 3, the patient’s haemoglobin again decreased to 65 g/L and she presented with moderate left thigh oedema and ecchymosis on physical examination. Another unit of pRBCs was administered and her haemoglobin subsequently increased appropriately to 73 g/L. To evaluate for ongoing haemorrhage, the orthopaedic surgery team recommended performing a CT angiography (CTA) of the left lower extremity on postoperative day 3. However, the patient declined the CTA at this time and continued with observation. On postoperative day 4, she continued to have increased ecchymosis and her haemoglobin decreased to 65 g/L. She subsequently received another unit of pRBCs and agreed to obtaining the CTA.

Investigations

On postoperative day 4, CTA of the left lower extremity was completed. The imaging demonstrated active extravasation of contrast from the surgical bed arising from the superior gluteal branches of the left internal iliac artery (figure 3). A faecal occult blood test was also suggested to evaluate for a gastrointestinal bleed and was negative.

Figure 3.

CT angiography of the left lower extremity demonstrating an ovoid haematoma with active extravasation of contrast material. The location of the haematoma is consistent with the source arising from the superior gluteal branch of the internal iliac artery.

Treatment

Following the CTA, the interventional radiology team was consulted to perform diagnostic angiography and possible embolisation. The angiography revealed a pseudoaneurysm arising from the inferior branches of the left SGA that was immediately cranial to the left femoral intramedullary nail (figure 4). As a result of this finding, coil embolisation of the left SGA and branches feeding the pseudoaneurysm was performed (figure 5).

Figure 4.

Angiography of the left superior gluteal artery demonstrating a pseudoaneurysm arising from its inferior branches. The pseudoaneurysm lies immediately cranial to the intramedullary nail.

Figure 5.

X-ray image of the left hip demonstrating embolisation coils along the left superior gluteal artery.

Following the embolisation procedure, the patient’s haemoglobin level remained stable and she did not require any additional blood products. On postoperative day 8, the patient was discharged home from the hospital.

Outcome and follow-up

At her 1-week follow-up, the patient’s left thigh ecchymosis was resolving and she denied any symptoms of anaemia. Her primary symptom of left hip pain was also significantly improved from her preoperative course. At 4 months follow-up, X-rays showed evidence of postoperative heterotopic ossification, however she was doing clinically well without any hip pain. At 7 months postoperation, she continued to do well and did not appear to have any long-term adverse effects from the SGA pseudoaneurysm.

Discussion

Vascular complications related to orthopaedic hip fracture surgery are rare, with studies reporting an overall incidence of about 0.2%.^{5 6} Of the reported cases, the majority of the iatrogenic injuries related to intramedullary femoral nailing involve branches of the profunda femoris artery.^5–10 Due to the proximity of the profunda femoris artery to the placement of the intramedullary femoral nail, the most common mechanism of injury is penetration of the vessel by a drill, retractor or screw.^{9 10} This subsequently results in either acute onset of intraoperative haemorrhage or pseudoaneurysm formation with delayed onset bleeding.⁸ There have also been reports of profunda femoris artery injury due to displaced fracture fragments secondary to iliopsoas muscle contraction during manipulation of the patient.^{5 11}

In terms of SGA injury during orthopaedic surgery, there are several case reports describing SGA injuries during percutaneous iliosacral screw insertion. Maled et al, Altman et al and Marmor et al all described SGA injuries following iliosacral screw insertion for unstable pelvic ring fractures.^{3 12 13} Collinge et al further identified significant risk of SGA injury with percutaneous iliosacral screw insertion by utilising a cadaver model.¹⁴ In their study, 18% of the iliosacral screws they placed caused injury to the superior gluteal neurovascular bundle.¹⁴

In contrast, SGA injury is not commonly associated with the fixation of femur fractures. We were able to identify only one previous report of SGA injury during intramedullary femoral nailing. Ward et al described a case of a 57-year-old woman with an atypical subtrochanteric stress fracture that developed an SGA bleed as a result of injury during placement of a guidewire to identify the insertion site for the cephalomedullary nail.¹ Similar to our case, the patient presented with thigh ecchymosis and several significant drops in her haemoglobin levels that all increased appropriately after blood transfusions.¹ The bleed was identified with CTA and the patient was ultimately treated with coil embolisation.¹ In our case, we suspect the injury occurred as an avulsion injury while reaming the femoral canal or during insertion of the intramedullary nail due to the proximity of SGA branches to the intramedullary nail insertion site, as evidenced by the angiography results. While the injury could have theoretically been caused by insertion of the guidewire as described by Ward et al, we carefully bluntly dissected after incising the IT band, therefore minimising this risk.

Our case demonstrates the importance of maintaining a high suspicion for vascular injury when a patient presents with acute anaemia in the postoperative setting, despite no evidence of intraoperative vascular injury. The patient’s operative course was unremarkable; there was no evidence of intraoperative vascular injury and blood loss was minimal. However, postoperatively, the patient presented with an insidious bleed. This was evidenced by the slowly progressive thigh ecchymosis with adequate peripheral perfusion and brisk distal pulses on physical examination and laboratory evidence of acute anaemia. It is important to note that we suspected injury of a small calibre vessel because the patient’s decrease in haemoglobin was incremental and the haemoglobin appropriately responded to pRBC transfusions by about 10 g/L per pack of blood. In contrast, injury to a large calibre vessel would most likely lead to brisk intraoperative haemorrhage, rapidly developing haematoma, lower extremity ischaemia and a loss of peripheral pulses. Therefore, we decided to proceed with angiography and coil embolisation because the patient did not present with any signs of large vessel injury that would have warranted surgical intervention.

Despite the low incidence of vascular injury associated with intramedullary femoral nailing, orthopaedic teams must maintain a high level of suspicion when patients present with postoperative acute blood loss anaemia and physical examination findings concerning for haemorrhage. These signs include, but are not limited to, increased pain, oedema, ecchymosis and hypotension. In addition, when administering blood transfusions to a patient for suspected haemorrhage, it is vital to note the improvement in the patient’s haemoglobin after the transfusion. An appropriate haemoglobin response often alludes to a small calibre vessel injury over a large vessel that necessitates surgical intervention. Bearing this in mind, SGA injury following intramedullary femoral nailing is an infrequent but serious complication that must remain on the differential when symptoms of haemorrhage arise.

Learning points.

• Iatrogenic vascular injury secondary to antegrade femoral intramedullary fixation is a rare but potentially life-threatening complication.

• Orthopaedic teams must maintain a high level of suspicion for vascular injury when patients present with postoperative acute onset anaemia.

• When present, vascular injury secondary to femoral nailing may involve not only the deep femoral artery but also the superior gluteal artery.