Author : O Brady

 Contributors : D McCormack, D Bennett, P Connolly, M Dolan, P Kenny, P Murray.

A 30 yr old male presented to the emergency department following a road traffic accident. He was the driver of the car. He was complaining of severe pain in his right thigh radiating down as far as his knee. No other injuries of note. He had a previous road traffic accident 10 years ago in which he sustained a fracture dislocation of his right hip. This was treated conservatively. He subsequently developed degenerative arthritis and had an arthrodesis performed 8 years ago.

 On examination the patient had a swollen right thigh. The leg was externally rotated, about 10 cm shorter than the left, with no neurovascular deficit.

How would you manage this case?

I just wanted to comment on the arthrodesis. I would still think that there is a role for hip fusion at this age in these circumstances. I think it can be done without so much metal however and most importantly I think it should leave the hip in neutral in the frontal plane, i.e. there should be no adduction/abduction as I am sure these positions contribute to late knee pain. I am not sure if there was a subtrochanteric osteotomy performed here to optimise femoral positioning. I suspect not because of the Cobra head plate.

From what I can see this man has had a hip arthrodesis with fixation using a cobra plate and I think there is a second plate along the proximal femur. Beneath the plates he has a short spiral fracture. The ideal position for ahip fusion is 15-30 degrees of flexion, 10-15 degrees of external rotation and neutral abduction-adduction.

 I think that the best way to manage this case would be to operate via the old incision with extension down to the fracture site. I would remove all the metal. Then I would correct the alignment of the limb via the fracture site. I would fix the fracture with a DCP plate, 8-10 holes in this position. Post-op I would keep him in a spica cast 1 and 1/2 leg, for 8-12 weeks. After the fracture is healed I would address the residual limb length discrepancy.

 Mr Paul Connolly

From the x-ray this man appears to have a spiral fracture of the femur at the junction of the lower third and middle third. He also has a huge amount of metal in his proximal femur from his previous hip arthrodesis.

His hip appears fused. I think this man should have the metal removed from his previous hip arthrodesis, and his fracture could be fixed with a retrograde femoral nail. I dont think any attempt should be made to correct the adduction deformity at this stage, this could be done once his fracture has healed, when pre-operative planning would be easier.

Paddy's option is aggressive but I just wonder what the vascularity of the fracture site would be like after removing that metal and applying another plate. There would be tremendous forces at that site and I note Paddy would like to further protect his fixation until union. That couldbe a long time. In order to protect the most important aspect of bone union I wonder whether an external fixator would be indicated It would have the plus factor of immediate stabilisation, relatively rapid mobilisation, partial weight bearing if a circular frame is used and a lot of choices later if there is a delay in union time.

Secondly, with regard to the choice of position of the leg for a hip arthrodesis, I think that any fusion of the hip will eventually lead to accelerated degeneration of joints above and below the fusion. However, my understanding is that the optimal position for ambulation is to have the hip slightly adducted. (5 degrees) Maybe the gait analysees will correct me, but in stance phase, in the coronal plane, is the limb adducted, taking body weight in line with the body line? If the hip is in neutral or abducted, is this not less efficient with regard to upper trunk sway etc.?

 Mr Derek Bennett

From the way this discussion is evolving,this patient seems to have four problems under consideration:

Spiral fracture of his femur.

Extensive arthrodesis with metalwork which may hamper internal fixation.

Hip arthrodesis whose position may or may not be optimal

A limb length discrepancy.

Two treatment objectives exist:

A healed axially aligned fracture which allows early mobilisation and weight bearing.

A satisfactory hip arthrodesis.

I think that the fracture treatment must take priority. Once this has healed, further consideration can be given to his hip arthrodesis. Various fixation techniques have been discussed, all of which have relative advantages and disadvantages and all of which will involve removal of the existing metalwork. The operative scenario will therefore be: fixation of a femoral fracture, in which the hip is arthrodesed in slight adduction and flexion, with no metal in the way. My personal preference would be for an intramedullary nail. Before starting this I would like to see further AP and lateral X-rays of hip and knee to confirm that nailing is feasible. If nailing is not possible for technical reasons my "fall-back position" would be plating of the fracture with consequent delay in weight bearing.

 The treatment plan I would suggest is therefore:

1. Further X-rays.

2. Removal of metalwork.

3. Locked intramedullary nailing.

Maybe I should have stated that the patient had no problem regarding his hip arthrodesis. I think that most orthopaedic surgeons prefer the adducted hip arthodesis position which improves gait and is said to decrease the ammount of lumbosacral stress when compared to a neutral or abducted hip.

When we looked at this patient we wanted the easiest solution to his problem. Therefore, we decided on the minimal of surgical intrvention to achieve stability of his fracture. Rather than take out all of his metalwork we decided to take out the lowermost few screws from both plates. This would allow us insert a nail with a long 'working length'. Through stab incisions the lowermost screwswere removed from the arthrodesis plates (Cobra & 4.5.mm D.C.P.). Then afull length retrograde femoral nail was inserted and locked proximally and distally.