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Heterotopic Ossification Prophylaxis

External Beam Radiotherapy as Prophylaxis for Heterotopic Ossification After Surgical Fixation of Acetabular Fractures: a Prospective, Randomized Feasibility Study

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04867278
Enrollment
117
Registered
2021-04-30
Start date
2021-05-09
Completion date
2023-12-31
Last updated
2024-12-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Acetabular Fracture, Heterotopic Ossification

Brief summary

One complication that can occur after surgery on the acetabulum is the development of bone in abnormal places such as muscle and soft tissues. There is some evidence that a single dose of radiation to the surgical site within 3 days of surgery will prevent this abnormal bone from forming. However, there are no high quality studies proving that radiation works any better than doing nothing at all. The purpose of our study is to determine whether there is a difference in abnormal bone formation after acetabular surgery when patients are treated with external beam irradiation versus no treatment.

Detailed description

Heterotopic ossification (HO) is a common complication after surgical fixation of acetabular fractures, with incidence rates reported as high as 90%. HO can be a debilitating complication and surgical excision for more severe cases carries a high complication rate. Numerous strategies have been employed to prevent HO formation but results are mixed and the optimal treatment strategy remains controversial. The most common modalities used to prevent HO formation are oral administration of indomethacin or single-dose external beam irradiation therapy (XRT). Despite the common use of indomethacin and observational data to support its use, more recent randomized controlled trials (RCTs) have failed to demonstrate any significant reduction in the incidence of severe HO when patients were administered 6 weeks of indomethacin versus placebo. Similarly, XRT has been shown to be effective against HO formation in smaller observational studies, but there are no adequately powered RCTs to support its use compared to placebo. Given the high incidence, impact on outcomes, and controversy regarding treatment, there remains a need for continued research to determine optimal treatment strategies for HO prophylaxis. While XRT remains standard of care for prophylaxis at many centers, including our own, there are no RCTs to support its use. Given the associated cost and resources, and potential risk even if minor, our study will help determine the feasibility of a larger RCT to help determine if the use of XRT is justified. For this feasibility study, eligible patients will be randomized to XRT versus control. Both arms will receive gluteus minimus debridement in the OR, which is the standard of care at Shock Trauma. If randomized to the treatment group, patients that undergo surgical fixation of an acetabular fracture via a posterior or combined anterior and posterior approach will undergo a single fraction of external beam radiotherapy to the surgical site within 72 hours of surgery. This treatment is currently the standard procedure performed for all patients who undergo a posterior or combined approach at our institution. The control treatment arm will only include gluteus minimus debridement in the OR and will not receive XRT. We will have 30 patients randomized to each group. We will look at consent rate, power, and HO formation on 3 month post-op radiographs.

Interventions

PROCEDUREDebridement

Gluteus minimus debridement in the OR

PROCEDUREExternal Beam Radiation (XRT)

Patients that undergo surgical fixation of an acetabular fracture will receive debridement and a single fraction of external beam radiotherapy to the surgical site within 72 hours of surgery.

Sponsors

University of Maryland, Baltimore
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Adult aged 18+ with an acute acetabular fracture * Indicated for surgical fixation via a posterior or combined anterior and posterior approach

Exclusion criteria

* Contraindication to radiotherapy such as history of cancer/RT * Patients that are getting an acute total hip arthroplasty at the time of fixation of the acetabular fracture * Not English speaking * Not a Maryland resident or likely to have difficulty returning for post-op follow up(s) (i.e. homeless, incarceration)

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With Severe HO Formation3 months post-opSevere HO formation classified as Brooker class III-IV.

Secondary

MeasureTime frameDescription
Number of Participants With Any HO Formation3 months post-opAny HO formation classified as Brooker class I-IV.

Countries

United States

Participant flow

Participants by arm

ArmCount
External Beam Radiation (XRT) With Debridement
Patients will receive gluteus minimus debridement in the OR, which is the standard of care at Shock Trauma. If randomized to the treatment group, patients that undergo surgical fixation of an acetabular fracture via a posterior or combined anterior and posterior approach will undergo a single fraction of external beam radiotherapy to the surgical site within 72 hours of surgery. This treatment is currently the standard procedure performed for all patients who undergo a posterior or combined approach at our institution. External Beam Radiation (XRT): Patients that undergo surgical fixation of an acetabular fracture will receive debridement and a single fraction of external beam radiotherapy to the surgical site within 72 hours of surgery. Debridement: Gluteus minimus debridement in the OR
54
Debridement Alone (Control)
The control treatment arm will only include gluteus minimus debridement in the OR and will not receive XRT. Debridement: Gluteus minimus debridement in the OR
50
Total104

Baseline characteristics

CharacteristicTotalDebridement Alone (Control)External Beam Radiation (XRT) With Debridement
Acetabular fracture dislocation50 Participants25 Participants25 Participants
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
3 Participants1 Participants2 Participants
Age, Categorical
Between 18 and 65 years
101 Participants49 Participants52 Participants
Age, Continuous36 years
STANDARD_DEVIATION 12
37 years
STANDARD_DEVIATION 13
35 years
STANDARD_DEVIATION 11
Associated fracture pattern50 Participants24 Participants26 Participants
Closed suction drain at wound closure42 Participants20 Participants22 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
3 Participants2 Participants1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
101 Participants48 Participants53 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Gluteus minimus muscle debridement100 Participants49 Participants51 Participants
Head Injury21 Participants10 Participants11 Participants
Mechanical ventilation29 Participants17 Participants12 Participants
NSAIDS for pain management38 Participants19 Participants19 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
2 Participants1 Participants1 Participants
Race (NIH/OMB)
Black or African American
65 Participants29 Participants36 Participants
Race (NIH/OMB)
More than one race
2 Participants1 Participants1 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
35 Participants19 Participants16 Participants
Region of Enrollment
United States
104 participants50 participants54 participants
Sex: Female, Male
Female
29 Participants10 Participants19 Participants
Sex: Female, Male
Male
75 Participants40 Participants35 Participants
Surgical Approach: Combined anterior and posterior11 Participants6 Participants5 Participants
Surgical Approach: Kocher-Langenbeck93 Participants44 Participants49 Participants
Tranexamic acid used34 Participants20 Participants14 Participants
Trochanteric osteotomy6 Participants3 Participants3 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 540 / 50
other
Total, other adverse events
2 / 543 / 50
serious
Total, serious adverse events
0 / 540 / 50

Outcome results

Primary

Number of Participants With Severe HO Formation

Severe HO formation classified as Brooker class III-IV.

Time frame: 3 months post-op

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
External Beam Radiation (XRT) With DebridementNumber of Participants With Severe HO Formation3 Participants
Debridement Alone (Control)Number of Participants With Severe HO Formation9 Participants
Secondary

Number of Participants With Any HO Formation

Any HO formation classified as Brooker class I-IV.

Time frame: 3 months post-op

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
External Beam Radiation (XRT) With DebridementNumber of Participants With Any HO Formation10 Participants
Debridement Alone (Control)Number of Participants With Any HO Formation17 Participants

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026