Avascular necrosis of the femoral head after intertrochanteric fractures

Avascular necrosis of the femoral head at 2 years after pertrochanteric fracture surgery: Case report

INTRODUCTION

The avascular necrosis of the femoral head represents the death of bone tissue due to the lack of blood supply. The disease has a progressive evolution and left untreated leads to femoral head collapse and severe arthritis.

CASE PRESENTATION

We present a case of a pertrochanteric fracture which has been successfully operated with a dynamic interlocking trochanteric gamma nail on the right hip. At 2 years after surgery the patient developed an incipient avascular necrosis of the femoral head. Despite the good positioning of the implant, we considered that the source of the pain was an intolerance of the implant, and thus we removed it. After implant removal, the patient was kept under observation and conservative treatment, to prevent further damage to the right hip and allow the healing to occur. At 6 months after the gamma nail was removed the X-rays revealed advanced avascular necrosis of the femoral head and secondary osteoarthritis on the right hip. The patient underwent surgery with an uncemented total hip arthroplasty.

DISCUSSION

There are a few discussions regarding the avascular necrosis of the femoral head. These discussions may include the predisposing risk factors, the treatment of choice and the postoperative complications.

CONCLUSION

The avascular necrosis of the femoral head is a complication of pertrochanteric fractures that can not be foreseen or avoided. The optimal treatment in these cases is uncemented total hip arthroplasty.

Comparison of proximal femoral nail antirotation blade and reverse less invasive stabilization system-distal femur systems in the treatment of proximal femoral fractures

OBJECTIVE

To compare the effects of proximal femoral nail antirotation blade (PFNA) and reverse less invasive stabilization system-distal femur (Liss-DF) systems in the treatment of proximal femoral fractures.

METHODS

Between June 2007 and October 2009, 41 proximal femoral fractures were treated, 22 with PFNA (group A) and 19 with reverse LISS-DF plates (group B). The time to starting full weight-bearing, fracture healing time, functional recovery (Parker and Palmer mobility score), neck-shaft angle discrepancies with the intact contralateral hip, preoperative American Society of Anesthesiologists (ASA) scores, the operation durations and amount of intraoperative bleeding were recorded and compared.

RESULTS

The mean follow-up period was 11.2 months (range, 10-12 months). Compared with Group A, Group B showed a statistically longer mean time to bear full body weight and heal their fractures, but a smaller neck-shaft angle discrepancy (all P < 0.05). The groups were similar in ASA score, operation duration, amount of intraoperative bleeding and Parker and Palmer mobility score.

CONCLUSION

Both PFNA and reverse Liss-DF were satisfactory for the treatment of proximal femoral fractures, but had different advantages. PFNA allowed earlier weight-bearing and accelerated fracture healing. Reverse Liss-DF more effectively avoided coxa vara and may be indicated for patients with very severe osteoporosis.

Assessment of vascularity of the femoral head using gadolinium (Gd-DTPA)-enhanced magnetic resonance imaging

In spite of extensive accounts describing the blood supply to the femoral head, the prediction of avascular necrosis is elusive. Current opinion emphasises the contributions of the superior retinacular artery but may not explain the clinical outcome in many situations, including intramedullary nailing of the femur and resurfacing of the hip. We considered that significant additional contribution to the vascularity of the femoral head may exist. A total of 14 fresh-frozen hips were dissected and the medial circumflex femoral artery was cannulated in the femoral triangle. On the test side, this vessel was ligated, with the femoral head receiving its blood supply from the inferior vincular artery alone. Gadolinium contrast-enhanced MRI was then performed simultaneously on both control and test specimens. Polyurethane was injected, and gross dissection of the specimens was performed to confirm the extraosseous anatomy and the injection of contrast. The inferior vincular artery was found in every specimen and had a significant contribution to the vascularity of the femoral head. The head was divided into four quadrants: medial (0), superior (1), lateral (2) and inferior (3). In our study specimens the inferior vincular artery contributed a mean of 56% (25% to 90%) of blood flow in quadrant 0, 34% (14% to 80%) of quadrant 1, 37% (18% to 48%) of quadrant 2 and 68% (20% to 98%) in quadrant 3. Extensive intra-osseous anastomoses existed between the superior retinacular arteries, the inferior vincular artery and the subfoveal plexus.

Avascular necrosis of the femoral head in pertrochanteric fractures: a report of 8 cases and a review of the literature

OBJECTIVE

To evaluate patients with pertrochanteric fractures (Type 31A1 + 2 ASIF/OTA classification) treated surgically and who subsequently developed avascular necrosis of the femoral head (ANFH).

SETTING

University hospital.

DESIGN

Retrospective clinical study and analysis of the literature.

PATIENTS

From 1995 to 2003 the authors operated on 1,373 patients with pertrochanteric fractures. Eight patients with a mean age of 69 years (range, 52-78 years) subsequently developed ANFH.

INTERVENTION

Five patients were treated with a dynamic hip screw (DHS), and 3 were treated with an intramedullary hip nail (IMHN).

RESULTS

All fractures in these 8 patients healed without complications in 3 to 4 months. Avascular necrosis of the femoral head developed 4 months to 4 years after the operation. Detailed analysis of these cases did not reveal any risk factors or errors in surgical technique to account for the ANFH. Results of a literature review of 41 cases in addition to our 8 cases give us reason to believe the etiology of postoperative AFNH following surgical treatment of pertrochanteric fractures is probable injury to the deep branch of the medial circumflex artery at time of fracture. Other possible risk factors include high-energy trauma, comminution, displacement of the fragments, and atypical fracture line.

CONCLUSIONS

ANFH develops in approximately 0.5-1% of all pertrochanteric fractures, mostly within 4 years after the injury and predominantly in patients older than 50 years of age. The diagnosis should be considered in patients who have undergone an operation previously and have symptoms that are unclear. Prevention of ANFH in these fractures includes an early reduction, stable fixation, and correct surgical technique.

Necrosis of the femoral head after fixation of trochanteric fractures with Gamma Locking Nail. A cause of late mechanical failure

Cut-out of the lag screw after fixation of trochanteric fractures with intramedullary devices like the Gamma Locking Nail is a well documented cause of late mechanical failure. Avascular necrosis of the femoral head after trochanteric fractures is an uncommon complication and several causes have been described. As far as we know, the relation of the mechanical failure of fracture fixation and avascular necrosis of the femoral head in trochanteric fractures has never been described. We present a study of six consecutive patients who underwent arthroplasty after cut-out of the lag screw fixation of a trochanteric fracture with Gamma Locking Nail. All six femoral heads were studied histologically and a clinical retrospective study was also performed. In all cases, we found homogeneous avascular necrosis of the femoral head; in all but one, revascularisation was present in every area examined. We suggest that after fixation of these trochanteric fractures with the Gamma Locking Nail, there is a transitory ischaemia, if the revascularisation is not enough to provide a strong support for the lag screw, it may result in late mechanical failure in these fractures.