[Postoperative radiotherapy in the prevention of heterotopic ossification after endoprosthetic hip joint replacement].

Abstract

BACKGROUND:

Following total hip arthroplasty high-grade heterotopic ossification occurs with a range of 0.5 to 27%. Local postoperative hip irradiation using different dosage and fractionation schedules reduces the incidence in high-risk cases on an average of 8%. The present retrospective study compares results after conventionally fractionated and high-dose radiotherapy.

PATIENTS AND METHOD:

A total of 50 hips (46 patients) from 2 different risk groups had complete follow-up. In group I (40 hips [80.0%]) radiotherapy was indicated after surgical excision of pre-existing high-grade heterotopic ossification, in group II (10 hips [20.0%]) for several risk factors (contralateral heterotopic ossification [n = 7], hypertrophic osteoarthritis [n = 2], spondylosis hyperostotica [n = 1]). In 28/50 cases (56.0%) conventionally fractionated irradiation with total doses ranging from 12.0 to 20.0 Gy was given, in 22/50 hips (44.0%) a high-dose irradiation consisting of 10.0 Gy given in 2 fractions on each of the first 2 postoperative days was applied. After a minimal observation period of 6 months (median: 22 months, range: 6 to 56 months) roentgenograms were analysed using a modified Brooker score.

RESULTS:

At follow-up, 2 hips in group I had recurrence of high-grade heterotopic ossification with the stages IIIA and IVB. In 1 case radiotherapy was interrupted after 3 x 2.0 Gy due to sepsis (IIIA), in the other case ectopic bone recurred from bony islands which layed outside the radiation portal (IVB). In group II, 9 patients had stage 0 and 1 patient stage IA. Statistical analysis using the Wilcoxon test showed a highly significant reduction of the amount of pre-existing heterotopic ossification (p < 0.0001) for both fractionation schedules. The comparison of both fractionation groups with the Whitney-Mann-U-test (p = 0.92) showed no statistical significant difference.

CONCLUSIONS:

The data about the high therapeutic efficacy of postoperative radiotherapy for prevention of heterotopic ossification were confirmed. Both fractionation schedules led to a sufficient reduction of high-grade heterotopic ossification in the 2 treated risk groups.

• Authors: R Heyd, G Strassmann, J Kirchner, B Schopohl, H D Böttcher
• Journal: Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al] (Strahlenther Onkol) Vol. 172 Issue 10 Pg. 543-52 (Oct 1996) ISSN: 0179-7158 [Print] Germany
• Vernacular Title: Postoperative Strahlentherapie zur Prävention heterotoper Ossifikationen nach endoprothetischem Huftgelenkersatz.
• PMID: 8966671 (Publication Type: Comparative Study, English Abstract, Journal Article)

Topics

• Adult
• Aged
• Aged, 80 and over
• Evaluation Studies as Topic
• Female
• Hip Prosthesis
• Humans
• Male
• Middle Aged
• Ossification, Heterotopic (prevention & control, radiotherapy)
• Postoperative Care
• Postoperative Complications (prevention & control, radiotherapy)
• Radiotherapy Dosage
• Radiotherapy, Adjuvant (methods, statistics & numerical data)
• Risk Factors