Utility of radiation in the prevention of heterotopic ossification following repair of traumatic acetabular fracture

Perioperative management of acetabular and pelvic fractures: evidence-based recommendations

PURPOSE

The American Academy of Orthopaedic Surgeons does not currently provide clinical practice guidelines for management of PAF. Accordingly, this article aims to review and consolidate the relevant historical and recent literature in important topics pertaining to perioperative management of PAF.

METHODS

A thorough literature review using PubMed, Cochrane and Embase databases was performed to assess preoperative, intraoperative and postoperative management of PAF fracture. Topics reviewed included: time from injury to definitive fixation, the role of inferior vena cava filters (IVCF), tranexamic acid (TXA) use, intraopoperative cell salvage, incisional negative pressure wound therapy (NPWT), intraoperative antibiotic powder use, heterotopic ossification prophylaxis, and pre- and postoperative venous thromboembolism (VTE) prophylaxis.

RESULTS

A total of 126 articles pertaining to the preoperative, intraoperative and postoperative management of PAF were reviewed. Articles reviewed by topic include 13 articles pertaining to time to fixation, 23 on IVCF use, 14 on VTE prophylaxis, 20 on TXA use, 10 on cell salvage, 10 on iNPWT 14 on intraoperative antibiotic powder and 20 on HO prophylaxis. An additional eight articles were reviewed to describe background information. Five articles provided information for two or more treatment modalities and were therefore included in multiple categories when tabulating the number of articles reviewed per topic.

CONCLUSION

The literature supports the use of radiation therapy for HO prophylaxis, early (< 5 days from injury) surgical intervention and the routine use of intraoperative TXA. The literature does not support the routine use of iNPWT or IVCF. There is inadequate information to make a recommendation regarding the use of cell salvage and wound infiltration with antibiotic powder. While the routine use of chemical VTE prophylaxis is recommended, there is insufficient evidence to recommend the optimal agent and duration of therapy.

Testicular Dose During Prophylaxis of Heterotopic Ossification with Radiation Therapy

AIM

A single-institution, retrospective study was performed to investigate potential techniques to minimize radiation exposure to the testicles during heterotopic ossification (HO) prophylaxis. We report the impact of split-beam technique (SBT) and different photon energies on the total dose of radiation received by the testicles during prophylaxis of HO.

MATERIALS AND METHODS

Between 2008 and 2010, we identified 64 patients with traumatic acetabular fractures who underwent surgery followed by radiation therapy (RT) without testicular shielding. Postoperative RT was delivered within 72 h in a single fraction of 700 cGy using 6-18 MV photons, without testicular shielding due to patient refusal. All patients underwent 3-D RT planning in which the testicles were contoured as a region of interest and dose-volume histograms (DVH) were generated. Additional treatment planning trials were created for each patient by utilizing a SBT medially and by using different photon energies (6, 10 and 18 MV) to study the effects of these maneuvers on the delivered dose to the testicles.

RESULTS

In reviewing the DVH, it was noted that the mean dose delivered to the testicles was 10 cGy (range=3-40). The maximum dose was 31 cGy (range=7-430). When SBT was utilized, a significant reduction in the mean (44%) and maximum (47%) doses delivered to the testicles was noted. Further reductions in the mean (26%) and maximum (14%) doses were achieved by using higher-energy (10-18 MV) beams. The radiation doses to the testicles from the CT simulation and the two portal images were estimated to be 4 and 1.5 cGy, respectively.

CONCLUSION

Low-dose prophylactic RT to prevent HO around the hip causes a low, but likely biologically meaningful, radiation dose to be delivered to the testicles. This dose could be further reduced by using a medial SBT and photon energies above 6 MV. Testicular shielding should be offered to all male patients receiving such RT. In addition, all patients should be informed about the consequences of testicular radiation as part of their informed consent.

Heterotopic Ossification in Acetabular Fracture Surgery

Heterotopic ossification (HO) is a common complication of the surgical treatment of acetabular fractures. HO is the formation of trabecular bone in soft tissues where bone does not usually occur. Over the last decade, many risk factors have been identified for HO after surgical fixation of acetabular fractures; however, prophylaxis and treatment of this condition are controversial. Potential preventive measures range from NSAIDs to external beam irradiation, but recent studies have questioned the utility of these measures. The Brooker classification system, which has been correlated with patient function and outcomes, is most commonly used to describe HO severity. Advances will assist in the diagnosis, prevention, and management of HO as well as the assessment of risk factors that could affect outcomes.

Heterotopic mesenteric ossification after a ruptured abdominal aortic aneurism: case report with a review of literatures

Heterotopic mesenteric ossification (HMO) is a rare disease that results in intra-abdominal ossification of unknown origin. An 88-year-old man developed an intestinal obstruction 2 weeks after undergoing an operation for a ruptured abdominal aortic aneurysm, resulting in intestinal obstructions those did not improved concervatively. During relaparotomy performed 30 days after the first operation, hard adhesions of the small intestine and mesentery were found; these adhesions were difficult to separate without damaging the serosa of the small intestine. We removed 240 cm of the small intestine and performed a jejuno-ileo anastomosis. Microscopically, trabecular bone tissue had increased irregularly in the fat tissue of the nodules with fibrosis, which were partially lined with osteoblasts. Accordingly, we histopathologically diagnosed the patient as having HMO. The patient was treated with NSAIDs and cimetidine to prevent the recurrence of HMO. No signs of recurrence have occurred as of one year after the second operation.

Is preoperative radiation therapy as effective as postoperative radiation therapy for heterotopic ossification prevention in acetabular fractures?

BACKGROUND

Prophylactic approaches to prevent heterotopic ossification after acetabular fracture surgery have included indomethacin and/or single-dose external beam radiation therapy administered after surgery. Although preoperative radiation has been used for heterotopic ossification prophylaxis in the THA population, to our knowledge, no studies have compared preoperative and postoperative radiation therapy in the acetabular fracture population.

QUESTIONS/PURPOSES

We determined whether heterotopic ossification frequency and severity were different between patients with acetabular fracture treated with prophylactic radiation therapy preoperatively and postoperatively.

METHODS

Between January 2002 and December 2009, we treated 320 patients with a Kocher-Langenbeck approach for acetabular fractures, of whom 50 (34%) were treated with radiation therapy preoperatively and 96 (66%) postoperatively. Thirty-four (68%) and 71 (74%), respectively, had 6-month radiographs available for review and were included. For hospital logistical reasons, patients who underwent operative treatment on a Friday or Saturday received radiation therapy preoperatively, and all others received it postoperatively. The treatment groups were comparable in terms of most demographic parameters, injury severity, and fracture patterns. Six-month postoperative radiographs were reviewed and graded according to Brooker. Followup ranged from 6 to 93 months and 6 to 97 months for the preoperative and postoperative groups, respectively. Post hoc power analysis showed our study was powered to detect a difference of 22% or more between patients with severe heterotopic ossification. Sample size calculations showed 915 subjects would be needed to detect a 5% relative difference in severe heterotopic ossification status between groups.

RESULTS

We detected no difference in heterotopic ossification frequency between the preoperative (eight of 36, 22%) and postoperative (19 of 71, 27%) groups (p=0.609). There was also no difference in heterotopic ossification severity between groups (p=0.666). Two of 36 (6%) in the preoperative group and three of 71 (4%) in the postoperative group developed clinically significant Grade III heterotopic ossification. No patients developed Grade IV heterotopic ossification.

CONCLUSIONS

We found no difference in heterotopic ossification frequency or severity when comparing preoperative and postoperative radiation therapy. However, given the relatively low frequency of heterotopic ossification in this population, in particular the frequency of severe or symptomatic heterotopic ossification, the possibility of a Type II error must be considered. Larger, prospective studies are required to confirm our no-difference finding, but insofar as the result in this fracture population mirrors that of the THA population, unless our finding is disproven, we believe radiation therapy can be given either before or after surgery, as dictated by the clinical scenario.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Surgical resection of severe heterotopic ossification after open reduction and internal fixation of acetabular fractures: a case series of 18 patients

OBJECTIVE

To evaluate the clinical results of surgical resection of severe heterotopic ossification (HO) after the open reduction and internal fixation (ORIF) of acetabular fractures.

METHODS

A retrospective chart review was performed between October 2005 and November 2010 on patients undergoing severe HO resection following an acetabular fracture ORIF. Our primary outcome was functional status evaluated by the Harris hip score (HSS). HO resection and hip release was performed using a Kocher-Langenbeck approach in all cases, and a combined radiation and indomethacin regimen was used to prevent HO recurrence. Plain radiographs were also used to evaluate the hip joint for arthritic changes and HO recurrence.

RESULTS

A total of 18 patients (17 males and 1 female) were included in our study analysis. The mean patient age was 36.8 (range: 22-54 years old) when HO resection surgery was performed. The mean time interval between acetabular fracture ORIF and HO resection was 9.9 months (range: 3-30 months): it was within 6 months in 7 patients, 6-12 months in 8 patients, and >12 months in 3 patients. The HO was graded as Brooker grade III in 8 patients and grade IV in 10 patients. The mean time interval between HO resection and the latest follow-up was 4.5 years (range: 2.1-7.8 years). The mean Harris hip score (HHS) was 84.5 (range: 38-100), with a clinical outcome rating of excellent in 9 patients, good in 3 patients, fair in 4 patients, and poor in 2 patients (good and excellent rating accounted for 66.7%). The mean hip joint motion arc was 194° (range: 90-260°). Complications included one intraoperative femoral neck fracture, 1 sciatic nerve injury, 2 femoral head avascular necrosis, and 6 mild HO recurrences (33.3%). There was 28.6% recurrence if HO resection was within 6 months and 36.4% if >6 months. There were no cases of severe HO recurrence, wound infections, deep vein thrombosis, or pulmonary embolism.

CONCLUSION

The early surgical resection of severe HO after an acetabular fracture ORIF can provide satisfactory results, however the complication rate is relatively high.

Computerized tomography-based radiotherapy improves heterotopic ossification outcomes

PURPOSE

To report the impact of computerized tomography (CT) based radiotherapy (RT) on heterotopic ossification (HO) outcomes.

METHODS

This is a single institution, retrospective study of 532 patients who were treated for traumatic acetabular fractures (TAF). All patients underwent open-reduction internal-fixation (ORIF) of the TAF followed by RT for HO prophylaxis. Postoperative RT was delivered within 72h, in a single fraction of 7Gy. The patients were divided into 2 groups based on RT planning: CT (A) vs. clinical setup (B).

RESULTS

At a median follow up of 8years the incidence of HO was 21.6%. Multivariate regression analysis revealed that group (A) vs. (B) had HO incidence of 6.6% vs. 24.6% (p<0.001), respectively. Furthermore, HO Brooker grade ≥3 was observed in 2.2% vs. 10.8% (p=0.007) in group (A) vs. (B), respectively. Thus, the odds of developing HO and Brooker grades ≥3 were 4.7 and 4.5 times higher, respectively, in patients who underwent clinical setup.

CONCLUSION

Our data suggest that using CT based RT allowed more accurate delineation of the tissues and better clinical outcomes. Although CT-based RT is associated with additional cost the efficacy of CT-based RT reduces the risk of HO, thereby decreasing the need for additional surgical interventions.

Early palsy of the sciatic nerve due to heterotopic ossification after surgery for fracture of the posterior wall of the acetabulum

We describe a patient in whom an initially intact sciatic nerve became rapidly encased in heterotopic bone formed in the abductor compartment after reconstruction of the posterior wall of the acetabulum following fracture. Prompt excision and neural release followed by irradiation and administration of indometacin resulted in a full neurological recovery and no recurrence 27 months later.

Radiation therapy for the treatment of benign vascular, skeletal and soft tissue diseases

The concept of radiation therapy for the treatment of benign diseases refers to the use of moderate to high-energy ionising radiation as part of the treatment of non-malignant, but not necessarily harmless, diseases. The usefulness of radiation therapy, based on the anti-inflammatory properties of ionising radiation, has long been known. Apart from the treatment of intracranial benign tumours, such as meningiomas and neurinomas, the prevention of cardiovascular restenosis or treatment of skeletal degenerative diseases are, without doubt, the main fields of action for radiation therapy in benign conditions. Nonetheless, many other non-cancer entities may benefit from ionising radiation therapy treatment. The purpose of this review is to highlight and update indications for treatment with radiation therapy in benign conditions, focusing on skeletal degenerative processes, vascular conditions and soft tissue diseases.

Effects of irradiation using a radioisotope-filled balloon on tissue hyperplasia caused by stent placement in a canine urethral model

PURPOSE

To evaluate 20 Gy and 40 Gy of intraluminal beta-irradiation using a 188Re-7mercaptoacetyltriglycine (MAG3)-filled balloon catheter to reduce tissue hyperplasia caused by covered stent placement for 12 weeks of follow-up in a canine urethral model.

MATERIAL AND METHODS

Ten dogs underwent 188Re-MAG3-filled balloon dilatation immediately after stent placement; 20 Gy at 1-mm tissue depth in group I (n = 5) and 40 Gy in group II (n = 5), whereas 5 dogs (group III) underwent conventional balloon dilatation only.

RESULTS

There were no significant differences among the three groups for percentage diameter of stenosis, although this was highest in group III. There was a tendency toward lower mean thickness of the epithelial layer and the papillary projection for out-stent area, and thickness of the papillary projection and degree of inflammatory cells for instent area in groups I and II compared with group III. Thickness of the papillary projection in out-stent area was significantly different among the three groups (P = 0.031). It was significantly less thick in group I than in group III (P < 0.05), whereas group II was not significantly different from group III.

CONCLUSION

188Re-MAG3-filled balloon dilatation has the potential to reduce tissue hyperplasia after 12 weeks of follow-up in a canine urethral model. The use of 20 Gy compared to 40 Gy did not show significant differences.

Prevention of heterotopic ossification in high-risk patients with total hip arthroplasty: the experience of a combined therapeutic protocol

The combination of radiotherapy and indomethacin for the prevention of heterotopic ossification (HO) in high-risk patients undergoing total hip arthroplasty (THA) has not been reported. The aim of the present study was to present the experience of our department with this combined therapeutic protocol. Fifty-four patients who underwent THA received a single dose of 7 Gy of postoperative radiotherapy and 75 mg of indomethacin for 15 days. Patients were analyzed for clinical and radiographical evidence of HO development at 1 year postoperatively. The overall radiographical incidence of HO was 20.4% (95% CI 10.6-33.5%), while only 1 patient with clinically significant HO was seen. Patients with secondary arthritis due to congenital hip disease had a statistically significantly higher incidence of HO compared with those with osteoarthrosis. The clinical assessment with the Merle d'Aubigné score showed that patients with radiographic documentation of HO had a lower mean score compared with those with no evidence of HO. No treatment-related side effects were seen. Combined radiotherapy and indomethacin was effective in preventing heterotopic ossification after total hip arthroplasty. The evaluation of this efficacy compared with radiotherapy or NSAIDs alone should be the future target of larger randomized designs.

Arthroplastie de hanche pour séquelle de fracture de l’acétabulum

PURPOSE OF THE STUDY

The aim of this retrospective analysis was to examine complications and technical difficulties observed during implantation of total hip arthroplasty (THA) after treatment of an acetabular fracture.

MATERIAL AND METHODS

Forty patients (thirty men and ten women), mean age 50 years, were included in the study. The acetabular fracture had been treated surgically in 23 and orthpedically in 17. Mean time from initial trauma to implantation of the THA was eleven years. Hydroxyapatite-coated cups were inserted without cement in 32 patients. Cemented cups in eight (with two Kerboull cross, one Muller ring, and five simple polyethylene). Five femoral stems were cemented. Preoperative planning was designed to restore the center of the initial hip rotation to avoid excessive cup medialisation. Acetabular defects found intra-operatively were significantly greater in the group of patients treated orthopedically than in those treated surgically (p = 0.02). Autografts were thus used more frequently in the former (65%).

RESULTS

One patient presented an intraoperative complication. The postoperative complications included phlebitis (n = 1), infection (n = 1), fibular nerve paralysis (n = 2), dislocation (n = 4), and heterotopic ossification (n = 7). The rate of postoperative complications was significantly higher in the group of patients treated surgically (52.2% versus 17.6%, p < 0.02). At last follow-up, mean 52 months, the mean Postel-Merle-d'Aubigne function score was 16.7. The rate of acetabular revision was 15% with four cemented cups being replaced at more than ten years due to aseptic loosening. Two press-fit cups were replaced early for infection in one patient and disassembly in another.

DISCUSSION

Despite the high rate of complications, the mid-term results were good, encouraging us to continue this procedure as the first intention treatment using either a press fit cup with or without an autograft, or a cemented cup with a metal ring (Kerboull or Burch-Schneider).

Heterotopic bone formation: irradiation of high risk patients

The Royal Marsden Hospital has adopted a policy for patient selection for the use of adjuvant radiotherapy to prevent heterotopic new bone formation (HTBF) limited to those at greater than 50% risk. The treatment protocol is 7 Gy post-operative megavoltage radiotherapy at mid-plane, in one fraction, given within 72 h of surgery. Since the introduction of this protocol in 1993, 26 joints have been treated in 25 patients. The majority of cases were young people with acetabular fractures resulting from road traffic accidents, often alcohol related. Follow-up studies in this group of patients has proved difficult, as many fail to attend for follow up, and others have moved out of the catchment area. Of the 14 cases for which follow-up data is available, 13 remain fully mobile. One has not mobilized since the time of treatment and continues to use crutches. There is one case of recurrent HTBF seen on X-ray after 8 months, but the joint was mobile. By 5 years, all cases have failed to attend for follow-up. The true long-term risks of this treatment policy may not be known for 30 years. The failure of patients to attend even short-term follow-up is a potential problem for clinical oncologists.

A prospective evaluation of the timing of postoperative radiotherapy for preventing heterotopic ossification following traumatic acetabular fractures

PURPOSE

Preoperative and immediate postoperative irradiation of traumatic acetabular fractures (TAF), although known to reduce heterotopic ossification (HO), can cause significant organizational and logistic difficulties. We sought to determine an acceptable time interval between surgery and radiation without compromising control, as well as to update our large experience and to further validate our treatment philosophy.

METHODS AND MATERIALS

Beginning in June 1995, we began a prospective study, irradiating 152 patients on postoperative days 1, 2, or 3. There were also 17 patients delayed further secondary to medical difficulties.

RESULTS

All patients treated since June 1995 received 700 cGy/1 fx. Fifty-eight patients received radiation within 24 hours of surgery, 41 within 2 days, 53 within 3 days, 13 within 4 days, and 4 were delayed further. Delaying irradiation for up to 4 days postoperatively caused no statistical increase in HO (p = 0.625). Of 263 patients in our retrospective cohort, HO occurred in 5.3% of patients who received irradiation versus 60% of patients who did not.

CONCLUSION

In our prospective study, we noted no perceptible increase in HO with up to a 3-day interval between surgery and radiotherapy. This allows a more structured treatment schedule and allows the patient more time to heal and recover. Updated results from our overall series continue to demonstrate that adjuvant radiation decreases the incidence and severity of HO after TAF.