Check radiography after fixation of hip fractures

K. MOHANTY, S.K. GUPTA and R.M. EVANS
Department of Orthopaedics and Radiology, Morriston Hospital, Swansea U.K.

Technological advances in radiography in the form of image intensification has not only made internal fixation of femoral neck fracture much easier but these high resolution films can be saved as hard copies and can also be reversed into 'positives' at a later date. However, requesting routine post-operative check radiographs for these fractures are still a common practice. A retrospective study was carried out to compare the quality of image intensifier films with conventional post-operative radiographs. 79 sets of films were reviewed with particular reference to adequacy of fixation and possible joint penetration by the screws. No significant difference was noted between the two sets of films. We suggest that routine post-operative radiographs after femoral neck fracture fixation are unnecessary unless there is some clinical indication. This has significant implications in relation to patient discomfort, radiation exposure and cost-effectiveness.

The use of an image intensifier during fixation of hip fractures is indispensable. It not only gives a high-resolution real time image but static images can be captured and retained as hard copy.

Haddad and Williams (1996) have compared the quality of thermal images with post-operative check radiographs and concluded that the post-operative films did not provide additional information.¹ In this study, we have compared the hard copy prints from an image intensifier with postoperative check radiographs in 79 patients who underwent internal fixation of hip fractures. The image intensifier used was the Phillips BV25 and the films were printed on a PMI 100 hard copy imager. The prints were of good quality.

We have also conducted a telephone survey of all major trauma centres in Wales to establish the incidence of the routine use of post-operative radiographs.

We selected 100 X-ray packets from the film library of patients who had internal fixation of hip fractures between 1996 and 1999. In 15 X-ray packets, some of the films were missing and were excluded from the study. In 6 patients, postoperative radiographs were electively not performed. Out of the remaining 79 sets of films, 44 patients had a dynamic hip screw inserted while the remaining 35 patients underwent screw fixation.

An "imaging quality review" proforma was designed for assessment of the image intensifier hard copies and the postoperative radiographs (Table 1). Each set of films was assessed by a consultant radiologist ( R.M.E.) and two orthopaedic specialist registrars and scored according to the proforma. One point was awarded for each criterion, making 10 the maximum possible score. Mean score was then calculated for image intensifier and radiographic films. Paired t test was used to calculate statistical differences.

Image availability		Image intensifier	Radiographs
Fracture reduction
Cortical penetration	AP
	Lat
Screw penetration	AP
	Lat
Fracture visibility	AP
	Lat
Prosthetic visibility
Joint visibility
Radiograph quality

A telephone survey was carried out of all the 11 hospitals in Wales dealing with major trauma. The superintendent radiographer in each institution was questioned as to their routine practice in femoral neck fractures.

The distribution of scores of image intensifier films and postoperative radiographs are shown in Tables 2 and 3, respectively. The mean score for the image intensifier films was 9.46 and for the post-operative radiographs it was 9.55. There was no statistical difference between the two sets of investigations. Post-operative radiographs did not add any further information to that obtained from the image intensifier films.

Hip score	Number of post-operative radiographs (Total 79)
10	57
9	9
8	9
7	1
6	3

Hip score	Number of post-operative radiographs (Total 79)
10	54
9	16
8	8
7	1
6	0

Our telephone survey indicated that almost all major trauma centres in Wales still followed the policy of carrying out routine post-operative radiographs for these types of patients.

Each year around £600 million is spent on imaging in the UK and it accounts for over 90% of radiation exposure to the population of the UK.² Each hip radiograph subjects the patient to a radiation dose of approximately 30 times that of a standard chest x-ray. We estimate that each hip radiograph (antero-posterior and lateral views) costs approximately £28. Over 500,00 hip fractures occur every year in this country and approximately half of these need internal fixation.^3,4 At this rate, this would amount to a saving of £10,000 per year for Morriston Hospital, Swansea, £100,000 per year for the whole of Wales and approximately £600,000 per year for the UK.

Images should be taken to show screw position in the head and to show adequate distal plate position and fixation. With appropriate positioning of the object close to the receiver unit, magnification is minimised and it is often possible to view the whole fixation device on a single film.

By avoiding routine post-operative radiographs, there can be saving on nursing, portering and radiographic duties, all of which are usually under pressure.

However, there will be clinical indications where early postoperative films are required and at times image intensifier copies may not provide the necessary quality and further imaging should be a clinical decision and not an administrative one. Also, if a series of radiographs need to be compared, then digitalised images can be reversed into ‘positives’ for easier comparison with later radiographs.

It is concluded that the use of routine post-operative check radiographs for internally fixed hip fractures is unnecessary unless there is some clinical indication.

The authors would like to thank Ms Tracy Adams, Superintendent Radiographer for her support and help in conducting this study.

Correspondence: S.K. Gupta, 13 Clos cwm du, Pontprennau,Cardiff CF23 8LE, U.K.

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Check radiography after fixation of hip fractures: is it necessary?