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Injury Vol. 28, No. 9-10, pp. 649-653, 1997 © 1997 Elsevier Science Ltd. All rights reserved

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PII: S0020-1383(97)00141-1

Surgical complications and implications of external fixation of pelvic fractures

Stephen Palmer', Adrian C. Fairbank 2 and Martin Bircher ~ 1Department of Orthopaedics, Queen Mary's University Hospital, Roehampton, UK, 2Department of Orthopaedics, South Thames (West) Region, Orthopaedic Training Scheme, London, UK and 3Department of Orthopaedics, St George's Hospital and Medical School, London, UK

The application of a pelvic external fixator can be a vital stage in the management qf patients with severe pelvic fractures, either as part of the resuscitation phase or as definitive treatment. This paper shows the complication rate of pelvic external fixation to be 47 per cent. This high rate increases the morbidity associated with the fracture, and may also interfere with the definitive manage- ment. The majority of complications were associated with pin placement and the pin-bone interface. An understanding of the principles of external fixation and knowledge of the correct methods of application should reduce this complication nTte. © 1997 Elsevier Science Ltd. All rights reserved.

Injury, Vol. 28, No. 9-10, 649-653, 1997

Introduction

The overall majority in patients with major pelvic fractures is approximately 10 per cent. This is due to severe haemorrhage from the pelvic fracture due to damage to the soft tissue elements of the pelvic basin, the associated injuries of other systems or the complications of major trauma.

The judicious application of a pelvic external fixator, and stabilization of the pelvis, can be a life- saving procedure and have a role in the resuscitation of patients with pelvic fractures. Its beneficial effect lies in apposing the bony surfaces and restoring the normal pelvic volume. Once the life has been saved, the external fixator may be used as the definitive treatment of the pelvic fracture alone or in combina- tion with traction, or replaced via internal fixation. It is vital that the fixator can be applied rapidly and safely without complications if it is to be beneficial.

The method by which the external fixator is applied and the timing of application may affect the morbidity by delaying or interfering with the surgical options for fracture fixation. A delay of application may result in higher mortality.

This paper looks at the complications of pelvic external fixators, and suggests methods of reducing these.

Method

A prospective study to assess the efficacy and safety of pelvic external fixators was compiled over a 3-year period between July 1991 and July 1994. Patients induded were those admitted either as primary or secondary referrals to one consultant who has an interest in the management of pelvic fractures. All patients included had an external fixator applied as part of their initial management. For some patients, the fixator was the definitive treatment.

Radiographs and computerized tomography (CT) scans were studied to group the fractures according to the classification system of Tile. Patient follow-up was performed in a dedicated outpatient clinic on a regular basis by one person (MDB). The results were amalgamated from prospective data sheets, hospital records, operating reports and a review of plain radiographs and CT. Recorded details included the timing of application of the external fixator, the position of pin application, complications and outcome.

Results

All patients who had an external fixator applied and were admitted to our unit were included. Twenty- four patients satisfied the entry criteria from a cohort of over 300 pelvic and acetabular fractures referred to our unit over the study period. There were 19 males and five females; the mean age was 32 years with a range of 13-54. The mechanisms of injury are recorded in Table I. The majority of injuries were sustained by car drivers or motorcyclists.

Ten patients sustained Tile Type B injuries (six B1 and three B2) and 14 patients Tile Type C fractures (eight C1, four C2 and two C3). Of the 24 admitted and treated with an external fixator, five died within 48 h of hospitalization - all had Tile Type C injuries and died as a result of haemorrhage plus severe associated injuries.

All patients except one had their external fixator applied within 6 h of admission. Nineteen had their

650 Injury: International Journal of the Care of the Injured Vol. 28, No. 9-10, 1997

fixator applied via the 'upper ' route, four via the 'lower' route and one patient had a combined approach.

Excluding the five patients who died within 48 h of arrival at hospital, all other patients left hospital alive. The mean time before transfer to our unit was 9 days with a range of 1-32 days. Of this group, nine sustained external fixator related complications, of which eight occurred prior to transfer and one occurred in our unit. This represents a complication rate of external pelvic fixation of 47 per cent.

For those requiring definitive surgical treatment, the mean time presurgery was 3 days with a range of 1-14 days. Six patients were operated upon within 24 h of admission. Ten patients underwent open reduction and internal fixation plus removal of the fixator as definitive treatment. Three of this group had complications: one patient had a fixator applied to a fracture that did not require external fixation; one patient had a separate pin placed into both femoral heads via the lower route (Figure 1) and one patient had a pin-site infection and skin necrosis that required a delay in surgery due to the proximity of

Table I. Mechanism of injury for patients included in the study

Mode of injury Number of patients

Car driver 8 Car passenger 1 Motorbike 7 Crush 3 Fall 4 Pedestrian 1

the necrotic infected tissue to the proposed surgical incision.

Five patients had open reduction and internal fixation and required repositioning of their supple- mental fixator (Figure 2). One patient had their fixator reapplied due to original poor pin-site placement, two had a number of loose pins (Figure 3), and in two others some pins were in soft tissues and not in bone: in one the pin tip appeared close to the large bowel on the CT scan, having cut out from the inner table of the pelvis (Figure 4).

One patient in our unit developed a superficial pin-site infection at 8 weeks post-insertion that was successfully treated with oral antibiotics and local wound toilet. Four patients had external fixation as definitive treatment for their pelvic fracture. There were no complications in this group, but in one patient who also had multiple lower limb injuries, attempts to fix these limb injuries were undertaken prior to stabilization of the pelvix. The patient became haemodynamically unstable until an external fixator was applied to the pelvis.

All patients have had their external fixator removed and no further surgical procedures to their pelvis have been performed.

Discussion

The number of patients satisfying the entry criteria in this study is small, reflecting the high mortality associated with pelvic fractures requiring stabiliza- tion. we suspect that many patients with severe pelvic fractures die in the primary receiving hospital. Our results included patients arriving directly at our hospital or as a result of transfer to our unit for

Figure 1. CT scan showing pins and tracks in femoral heads (arrowed).

Palmer et al.: External fixation of pelvic fractures 651

Figure 2. Incomplete reduction of open book fracture.

further intervention. The severity of the injuries is reflected in the five deaths occurring within 48 h of transfer to our unit.

Our results show that the time delay between injury and transfer to a specialized unit is high, averaging 9 days. There is a 50 per cent decrease in wound infection rates if the operation is performed less than 36h post-injury, compared with those operated on after 36 h 1. The reason for the delay may be attributed to a combination of factors:

(1) failure of the referring hospital to recognize the need for early active surgical treatment;

(2) the physical condition of the patient, e.g. too ill for transfer;

(3) the availability of a bed at the receiving hospital; (4) obtaining appropriate means of transport in cases

travelling from abroad, e.g. by aircraft.

On arrival at the specialist centre, definitive treat- ment should be performed once the patient is ready

Figure 3. Loose pins.

652 Injury: International Journal of the Care of the Injured Vol. 28, No. 9-10, 1997

Figure 4. Pin adjacadent to large bowel.

for operation and appropriate investigations have been completed. Delay thus occurs due to the logistics of arranging tests, a lack of operating time and the availability of the surgeon with the required experience to perform the procedure.

In our series the complication rate of application of external fixators to the pelvis was 47 per cent. All except one of these complications was as a result of application of the fixator prior to transfer. This is a high complication rate and leads to a possible delay in operation and an increased morbidity. The majority of complications were due to poor pin position, often because of missing the iliac crest when using the 'upper' route, and in penetration of the femoral head with the 'lower' route.

The upper route requires a non-parallel pin system, as the crest is curved in shaped (Figure5). The crest has an overhang laterally and therefore the entry point should be just to the medial side of the midline. If the hemipelvis is greatly displaced the use of relieving incisions is often necessary and allows the pelvis to be reduced and the pin to move along the line of incision. This avoids a large skin and soft tissue defect. The crest should be perforated with a drill, and then the pin should be inserted and allowed to find its own path within the cancellous bone of the iliac wing. A suitable frame can then be applied.

The lower route, just inferior to the anterior inferior iliac spine and above the acetabular dome, must be identified with the use of an image intensi- fier. Open dissection and exposure of the crest allows accurate placement and application of a parallel pin system frame (Figure 5).

Cadaver studies have shown that the strength of the pins applied via either route is equal. Lower route placement does allow easier access to the abdomen, but the anatomical landmarks used for the

FigureS. Parallel (lower route) and non-parallel (upper route) pin placement.

Palmer et al.: External fixation of pelvic fractures 653

fixator's application via this method are much less readily definable than those via the upper route technique.

Pelvic external fixation is a valuable part of the emergency, life-saving resuscitation of the severely injured patient. Poor pin placement is the commonest complication after application, and accurate pin position is essential.

R e f e r e n c e s

1 Noordeen M. H. Pin placement fixation. Injury 1993; 24: 581.

Paper accepted 18 August 1997.

in pelvic external

Requests for reprints should be addressed to: Mr Martin Bircher FRCS, Consultant in Orthopaedics, St George's Hospital and Medical School, Blackshaw Road, London SW17 0QT, UK.