Heterotopic Ossification Prophylaxis Research Articles

The Use Of External Beam Radiation Therapy For Heterotopic Ossification Prophylaxis After Surgical Fixation Of Acetabular Fractures: A Randomized Controlled Trial.

To determine the effect of external beam radiation (XRT) on preventing severe heterotopic ossification (HO) after acetabular surgery. Design: Randomized controlled trial. Two level I academic trauma centers. Patients with an acetabular fracture (OTA/AO type 62) surgically treated through a posterior or combined anterior and posterior approach.Outcome Measures and Comparisons: Radiographic HO was determined using Brooker Classification at the last follow-up. The primary outcome was severe HO (Brooker class III-IV). The secondary outcome was any HO (Brooker class I-IV). The incidence of radiographic HO was compared between patients that did and did not undergo postoperative XRT. The results were analyzed in both an intention-to-treat (randomized to XRT) and as-treated (received XRT) basis. Severe HO occurred in 3 of 54 (6%) patients randomized to XRT and 9 of 50 (18%) patients randomized to no XRT (odds ratio (OR) 0.24, 95% confidence interval (CI) 0.05 to 0.94; p=0.05). Any HO occurred in 10 (19%) patients assigned to XRT and 17 (34%) patients in the no XRT control group (OR 0.39; 95% CI 0.13 to 1.05; p =0.07). The findings of this dual-center randomized controlled trial suggest that XRT after acetabular surgery significantly reduced the odds of severe HO compared to patients that did not receive XRT. These results can help guide shared decision-making between surgeons and patients regarding the use of XRT for HO prophylaxis. Level I, therapeutic.

The Use of Tranexamic Acid for Primary Prophylaxis of Heterotopic Ossification Following Total Hip Arthroplasty

BackgroundHeterotopic ossification (HO) is a relatively common complication after total hip arthroplasty (THA) and can range from a radiographic observation only to severely disabling and requiring revision surgery. Prophylaxis is recommended for high-risk patients, though the ideal method and targeted population are open to debate. Tranexamic acid (TXA) is a medication increasingly being used to reduce blood loss associated with orthopaedic surgeries, including THA. MethodsA retrospective review of 357 patients undergoing THA from November 2020 through December 2023 was conducted. The patients were grouped based on whether they received intravenous TXA perioperatively or not, and their propensity score matched 2:1 TXA to no TXA on age, body mass index, sex, Charlson Comorbidity Index, and perioperative celecoxib use. Univariate and multivariate analyses were performed. ResultsAfter propensity score matching, the only significant differences between groups were American Society of Anesthesiologists (ASA) scores and preoperative celecoxib use between groups, as the TXA group had fewer patients who had an ASA of 3 or more (38.9 versus 58.5%, P < 0.001) and more patients who had taken celecoxib preoperatively (16.3 versus 5.9%, P = 0.010). Perioperatively, patients were more likely to undergo THA using the anterior approach (74.5 versus 57.6%, P = 0.002) and were more likely to receive postoperative celecoxib prescriptions (44.8 versus 31.4%, P = 0.021), but there was no difference in other nonsteroidal anti-inflammatory drug (NSAID) usage postoperatively. Postoperatively, patients who received TXA had a lower rate of HO on the last postoperative x-ray (20.1 versus 33.9%, P = 0.007). Multivariable logistic regression, to assess predictors of HO, found that patients who had TXA were 42% less likely to have visible HO (OR [odds ratio] = 0.58, P = 0.047), while holding surgical approach, American Society of Anesthesiologists score, preoperative and postoperative celecoxib use, and postoperative other nonsteroidal anti-inflammatory drug use constant. ConclusionsThe use of TXA in patients undergoing primary THA results in a decreased likelihood ofHO formation on postoperative x-rays.

PERIPROSTHETIC JOINT INFECTION AND HETEROTOPIC OSSIFICATION AFTER TOTAL HIP ARTHROPLASTY: A NARRATIVE REVIEW

This meta analysis address the relationship between infection developing after total hip arthroplasty (THA) and heterotopic ossification (HO). To identify the gaps in available knowledge, we screened for full-length peer-reviewed research articles listed in PubMed, Embase, and Web of Science over the past 20 years. The following search terms and Boolean operators were used: heterotopic ossification AND infection AND (hip replacement OR hip arthroplasty). The search resulted in the identification of as few as 14 articles describing periprosthetic joint infection (PJI) and HO after THA. Data summarized from 6 studies suitable for further meta-analysis yielded a cumulative sample size of 753 observations, with 186 recorded events of HO. The pooled RR was estimated at 2.22 (95% CI: 1.00 to 4.91, p = 0.0497), suggesting a more than twofold risk of HO compared to the group without PJI. In conclusion, there is a clear association between a higher risk of HO and PJI. Basic research findings support the hypothesis that bacterial pathogen-associated molecular patterns (PAMPs) can lead to osteogenesis through a toll-like receptor (TLR) and nuclear factor kappa B (NF-κB) pathway in the course of HO development. Together, these results suggest that HO prophylaxis should always be prescribed in PJI after THA. Moreover, during revisions following THA for presumed non-septic reasons, the presence of HO warrants consideration for infection, as there is a potential heightened risk of pathologic ossification induced by PAMPs.Keywords: heterotopic ossification; total hip arthroplasty; total hip replacement; periprosthetic joint infection; bacteriaAuthors Ł. Pulik and P. Łęgosz contributed equally to this work.

Classification and Incidence of Heterotopic Ossifications in Relation to NSAID Prophylaxis after Elbow Trauma

Heterotopic ossification (HO) after elbow trauma can be responsible for significant motion restrictions. The study’s primary aim was to develop a new X-ray-based classification for HO of the elbow. This retrospective study analyzed elbow injury radiographs from 138 patients aged 6–85 years (mean 45.9 ± 18) who underwent operative treatment. The new classification was applied at 6 weeks, 12 weeks, and 6 months postoperatively. The severity of HO was graded from 0 to 4 and localization was defined as r (radial), p (posterior), u (ulnar) or a (anterior) by two observers. The patients were categorized based on injury location and use of non-steroidal anti-inflammatory drugs (NSAIDs) for HO prophylaxis. The correlations between the generated data sets were analyzed using Chi-square tests (χ2) with a significance level of p &lt; 0.05. The inter- and intraobserver reliability was assessed using Cohen’s Kappa. In 50.7% of the evaluated X-rays, the formation of HO could be detected after 12 weeks, and in 60% after 6 months. The analysis showed a significant correlation between the injury’s location and the HO’s location after 12 weeks (p = 0.003). The use of an NSAID prophylaxis did not show a significant correlation with the severity of HO. The classification showed nearly perfect inter- (κ = 0.951, p &lt; 0.001) and intrareliability (κ = 0.946, p &lt; 0.001) according to the criteria of Landis and Koch. Based on the presented classification, the dimension and localization of HO in the X-ray image can be described in more detail compared to previously established classifications and, thus, can increase the comparability of results across studies.

Bony encasement of the ulnar nerve secondary to heterotopic ossification of the elbow: an evaluation of long-term outcomes

BackgroundUlnar neuropathy at the elbow caused by heterotopic ossification (HO) is a rare condition. This retrospective study aims to report on 32 consecutive cases of ulnar nerve encasement caused by elbow HO and evaluate long-term outcomes of operative management and a standardized postoperative rehabilitation regimen. MethodsA retrospective case series was conducted on 32 elbows (27 patients) that underwent operative management of bony ulnar nerve encasement. All procedures were performed in the inpatient setting at an Academic Level 1 Trauma Center from September 1999 to July 2021 by one of three fellowship-trained shoulder and elbow. Postoperatively, all patients received formal physical therapy, heterotopic ossification prophylaxis (30 received indomethacin, 2 received radiation), and a structured continuous passive motion machine regimen. Patient demographics, age, gender, type of injury, history of tobacco use, and medical comorbidities were obtained to include in the analysis. Long-term follow-up examinations were performed to evaluate elbow flexion-extension arc of motion, Mayo Elbow Performance Scores (MEPS), and visual analog scale (VAS) pain scores. ResultsThirty-two elbows with complete bony ulnar nerve encasement secondary to HO were identified (14 from burns, 15 from trauma, 3 closed head injuries). Following surgery, the mean flexion-extension arc of motion improved significantly, increasing from 21° to 100° at long-term follow-up (average 8.7 years, range 2-17 years), with statistically significant improvements in preoperative versus long-term postoperative elbow extension (p < 0.001), flexion (p < 0.001), and total arc of motion (p < 0.001). There was a statistically significant improvement in pre- vs. post-procedure ulnar nerve function, as demonstrated by a decrease in average McGowan grade (1.2 to 0.7; p = 0.002). Additionally, 63% of patients with preoperative ulnar neuropathy symptoms (20/32) had either complete resolution or subjective improvement after surgery. The mean time from injury to surgery was 518 days (range 65-943 days). Age, gender, time to surgery, and medical co-morbidities were not associated with outcomes. The complication rate was 9% (3/32). Patients had an average flexion-extension arc of motion of 97 degrees and average MEPS of 80 (“good”) at long-term follow-up. ConclusionsThe combination of operative management, postoperative heterotopic ossification prophylaxis, and a regimented rehabilitation program has proven to be a durable solution for treating and ensuring good long-term functional outcomes for patients with elbow HO and bony ulnar nerve encasement. This treatment approach leads to superior range of motion, improved or resolved ulnar neuropathy, and good to excellent long-term functional outcomes.

Efficacy of ibuprofen and indomethacin as prophylaxis of heterotopic ossification: a comparative study

The prophylactic action of non-steroidal anti-inflammatory drugs (NSAIDs) in heterotopic ossification (HO) was first described following analgesic therapy with indomethacin. Following that evidence, several compounds have been successfully used for prophylaxes of HO. Ibuprofen has been also proposed for the prevention of HO following THA. The present study compared the administration of ibuprofen for three weeks versus indomethacin as prophylaxis for HO following primary THA. In all THA procedures, pre- and post-operative protocols were conducted in a highly standardized fashion. The type of HO prophylaxis (indomethacin 100 mg/daily or ibuprofen 100 mg/daily) was chosen according to a chronological criterion: from 2017 to 2019 indomethacin was used, whereas from 2019 to 2022 ibuprofen was administered. In case of allergy or intolerance to NSAIDs, no prophylaxis was performed, and patients were included as a control group. All patients who underwent an anteroposterior radiography of the pelvis at a minimum of 12 months following THA were considered for inclusion. On admission, the age and sex of the patients were recorded. Moreover, the causes of osteoarthritis and the date of surgery were recorded. The grade of HO was assigned by a blinded assessor who was not involved in the clinical management of the patients. The modified Brooker Staging System was used to rate the efficacy of the interventions. Data from 1248 patients were collected. 62% (767 of 1248 patients) were women. The mean age was 67.0 ± 2.9 years. The mean follow-up was 21.1 ± 10.8 months. In the ibuprofen group, 73% of patients evidenced Brooker 0, 17% Brooker I, and 10% Brooker II. In the indomethacin group, 77% of patients evidenced Brooker 0, 16% Brooker I, 6% Brooker II. No patient in the ibuprofen and indomethacin group developed Brooker III or IV. In the control group, 64% of patients evidenced Brooker 0, 21% Brooker I, 3% Brooker II, and 12% Brooker III. No patient in the control group developed Brooker IV HO. Concluding, three weeks of administration of ibuprofen demonstrated similar efficacy to indomethacin in preventing HO following primary THA. The prophylaxis with ibuprofen or indomethacin was more effective in preventing HO compared to a control group who did not receive any pharmacological prophylaxis.

The Inpatient Consultation Experience in Radiation Oncology: A Contemporary Evaluation of a Single Academic Institution

Participating in an inpatient consultation service is an essential aspect of radiation oncology residency training. However, there are no reports in the literature describing the inpatient on-call experience. To better describe the clinical burden and define the learning opportunities associated with inpatient consultation service participation, inpatient on-call data were tracked and assessed. From July 1, 2022, through Dec. 31, 2022, radiation oncology residents covering the on-call pager for the inpatient consultation service spanning two hospitals at a single academic institution prospectively self-reported the total number of pages, new consultations, inpatient treatment starts, and treatment indications. Patient billing records and paging logs were reviewed to confirm self-reported cases and track the number of business days between simulation and the first fraction of treatment. A new inpatient consultation was defined as a novel encounter requiring independent evaluation; as such, patients admitted during an ongoing course of radiotherapy who continued the planned course while inpatient were not included. During the initial six months of tracking, on-call residents received a total of 607 pages with an average of 23.1 pages per week (range: 14-38). Of these pages, 212 were for new inpatient consultations with an average of 8.1 consultations per week (range: 2-15). Out of these 212 new consultations, 75 patients (35%) were treated on an inpatient basis. Nine patients (12%) received their first fraction of treatment on the same day as simulation, 13 (17%) on the next day, 11 (15%) two days after, 22 (29%) three days after, and 20 (27%) four or more days after simulation. The most common indications for urgent treatment were malignant spinal cord compression (27%), brain metastases (24%), tumor-related bleeding (8%), malignant obstruction of the airway or vasculature (8%), painful bone metastases (7%), and heterotopic ossification prophylaxis (7%). The most common primary sites of disease were leukemia/lymphoma (16%), gastrointestinal (13%), breast (11%), lung (9%), gynecologic (9%), sarcoma (9%), and benign (9%). Each individual resident's caseload differed greatly in quantity, indication, treatment site, and primary site over this six-month time period. In this longitudinal analysis at a single academic institution, the radiation oncology inpatient consultation service experience was highly variable and diverse in clinical volume and treatment indication on a week-to-week and resident-to-resident basis. Exposure to radiation oncology emergencies is a vital component of residency training. However, the unpredictable nature of inpatient on-call scenarios can lead to variable educational experiences. Tracking inpatient on-call cases during residency may help identify areas needing improvement to enhance both patient care and residency training.

NIR-triggered photodynamic therapy of traumatic heterotopic ossification with a type II collagen-targeted photosensitizer

Traumatic heterotopic ossification (HO) represents an intractable sequela following trauma with no currently effective prophylaxis or treatment. Photodynamic therapy (PDT) is a non-invasive treatment for various proliferative diseases. However, the specific effects of PDT on HO development remain unclear. In this study, the therapeutic potential of a near-infrared (NIR) probe-WL-808, composed of type II collagen-binding peptide (WYRGRL) and a PDT photosensitizer (IR-808), was evaluated for the innovative HO-targeted PDT approach. In vitro studies indicated that WL-808 could induce chondrocyte apoptosis and inhibit cell viability through ROS generation under NIR excitation. In vivo, the efficacy of WL-808-mediated PDT was tested on the tenotomy HO model mice. WL-808 specifically targeted the type II collagen cartilaginous template of HO, promoting cell apoptosis and enhancing extracellular matrix (ECM) degradation under 808 nm NIR excitation, which inhibited the final ectopic bone formation. Moreover, no obvious toxicity or side effects were detected after treatment with WL-808. Taken together, WL-808-mediated PDT significantly diminished ectopic cartilage and subsequent bone formation, providing a new perspective for HO prophylaxis and treatment.

Is External Beam Radiation Therapy Really Associated With Low Rates of Heterotopic Ossification After Acetabular Surgery?

Describe rate of postoperative heterotopic ossification (HO) after acetabular surgery in patients who received external beam radiation (XRT) as HO prophylaxis. Retrospective. Level I trauma center. Consecutive series of patients who presented to a single, level I, academic trauma center over a 10-year period (2008-2018) for surgical fixation of an acetabular fracture. Patients eligible for inclusion were those who underwent surgical fixation of an acetabular fracture through a posterior (Kocher-Langenbeck), combined anterior and posterior, or extensile exposure. Patients were excluded if an isolated anterior approach was performed or if an acute total hip arthroplasty was performed at the time of index surgery. XRT. Severe HO (Brooker class III or IV). The severe HO (Brooker class III or IV) rate for entire cohort was 12% (44 of 361 patients). Of these 44 patients, 30 patients were classified as Brooker III and 14 patients were classified as Brooker IV. The Brooker IV rate for the entire cohort was 4% (14 of 361 patients). Severe HO rates showed a declining trend over the period examined, with a risk reduction of -1.0% per year (95% confidence interval -2.1% to 0.2%; P = 0.10). To our knowledge, this is the largest single consecutive series on acetabular fracture patients who received XRT as HO prophylaxis. The overall severe HO rate was 12%, which is similar to other comparably large series data on patients who did not receive XRT after surgical fixation acetabular fractures. Although these data suggest that XRT may not be beneficial when used universally for all patients, comparative studies are required to rule out the benefits of XRT for preventing HO in this population. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Heterotopic Ossification Remodeling After Acetabular Surgery: A Natural History Case Report.

A 30-year-old woman presented with a transverse plus posterior wall acetabular fracture and underwent operative fixation through a Kocher-Langenbeck approach. Shared decision was made for no heterotopic ossification (HO) prophylaxis. The patient developed symptomatic HO and was scheduled for resection, which was delayed because of the pandemic. She returned with interval remodeling of HO and symptom resolution. No surgery was required. HO is a common complication after acetabular injury. Resection is the treatment of choice for symptomatic HO. We are not aware of other reports of spontaneous remodeling of symptomatic HO such that it no longer required surgery.

Indomethacin for heterotopic ossification prophylaxis following surgical treatment of elbow trauma: a randomized controlled trial

Heterotopic ossification is a frequent complication following surgical treatment of elbow trauma. The use of indomethacin to prevent heterotopic ossification is reported in the literature; however, its effectiveness is controversial. The purpose of this randomized, double-blind, placebo-controlled study was to determine whether indomethacin is effective in reducing the incidence and severity of heterotopic ossification after surgical management of elbow trauma. Between February 2013 and April 2018, 164 eligible patients were randomized to receive postoperative indomethacin or placebo medication. The primary outcome was the incidence of heterotopic ossification on elbow radiographs at 1-year follow-up. Secondary outcomes included the Patient Rated Elbow Evaluation score, Mayo Elbow Performance Index score, and Disabilities of the Arm, Shoulder and Hand score. Range of motion, complications, and nonunion rates were also obtained. At 1-year follow-up, there was no significant difference in the incidence of heterotopic ossification between the indomethacin group (49%) and the control group (55%) (relative risk, 0.89; P=.52). There were no significant differences in postoperative Patient Rated Elbow Evaluation, Mayo Elbow Performance Index, and Disabilities of the Arm, Shoulder and Hand scores or range of motion (P=.16). The complication rate was 17% in both the treatment and control groups (P>.99). There were no nonunions in either group. This Level I study demonstrated that indomethacin prophylaxis against heterotopic ossification in the setting of surgically treated elbow trauma was not significantly different from placebo.

Role of aspirin in the prevention of heterotopic ossification following total hip replacement: a systematic review and meta-analysis.

To systematically investigate if aspirin (ASA), used as venous thromboembolism (VTE) prophylaxis, plays a role in the prevention of heterotopic ossification (HO) following total hip arthroplasty (THA) and if ASA dosage impacted the rate of HO. Eligible studies published from January 2000 to July 2022 were identified from the computerized searching of PubMed, Scopus and Web of Science. HO was defined according to Brooker Classification. Pooled risk ratios (OR) and 95% confidence interval (CI) were estimated under a random-effect model. Additionally, combined HO incidences were compared according to ASA dosage (a regular dose of 325 bid vs. a low dose of 81 mg bid/162 mg qd). Thirteen studies were included. ASA administered for VTE prophylaxis was significantly associated with a reduced risk of all-grade HO following THA (univariate, OR: 0.50, 95% CI: 0.34-0.74, P < 0.001; multivariate, OR: 0.60, 95% CI: 0.49-0.73, P < 0.001). Similar results could be observed for high-grade HO (univariate, OR: 0.57, 95% CI: 0.36-0.89, P = 0.015; multivariate, OR: 0.50, 95% CI: 0.27-0.92, P = 0.026). There was a non-significant trend towards a higher incidence of HO formation for low-dose ASA (31%, 95% CI: 29-34%), compared with regular-dose ASA (21%, 95% CI: 11-33%) (P = 0.069 under test of interaction). ASA can be an effective option for HO prophylaxis. More well-designed trials with long-term follow-ups are encouraged to confirm the current findings and to investigate the effect of ASA dosage on HO reduction.

The impact of heterotopic ossification prophylaxis after surgical fixation of acetabular fractures: national treatment patterns and related outcomes

BackgroundHeterotopic ossification (HO) is a common complication after surgical fixation of acetabular fractures. Numerous strategies have been employed to prevent HO formation, but results are mixed and optimal treatment strategy remains controversial. The purpose of the study was to describe current national heterotopic ossification (HO) prophylaxis patterns among academic trauma centers, determine the association between prophylaxis type and radiographic HO, and identify if heterogeneity in treatment effects exist based on outcome risk strata. MethodsWe used data from a subset of participants enrolled in the Pragmatic Randomized Trial Evaluating Pre-Operative Alcohol Skin Solutions in Fractured Extremities (PREPARE) trial. We included only patients with closed AO-type 62 acetabular fractures that were surgically treated via a posterior (Kocher-Langenbeck), combined anterior and posterior, or extensile exposure. PREPARE Clinical Trial Registration Number: NCT03523962 Patient population This cohort study was nested within the Pragmatic Randomized Trial Evaluating Pre-Operative Alcohol Skin Solutions in Fractured Extremities (PREPARE) trial. The PREPARE trial is a multicenter cluster-randomized crossover trial evaluating the effectiveness of two alcohol-based pre-operative antiseptic skin solutions. All PREPARE trial clinical centers that enrolled at least one patient with a closed AO-type 62 acetabular fracture were invited to participate in the nested study. Results277 patients from 20 level 1 and level 2 trauma centers in the U.S. and Canada were included in this study. 32 patients (12%) received indomethacin prophylaxis, 100 patients (36%) received XRT prophylaxis, and 145 patients (52%) received no prophylaxis. Administration of XRT was associated with a 68% reduction in the adjusted odds of overall HO (OR 0.32, 95% CI, 0.14 – 0.69, p = 0.005). The overall severe HO (Brooker classes III or IV) rate was 8% for the entire cohort; XRT reduced the rate of severe HO in high-risk patients only (p=0.03). ConclusionHO prophylaxis patterns after surgical fixation of acetabular fractures have changed dramatically over the last two decades. Most centers included in this study did not administer HO prophylaxis. XRT was associated with a marked reduction in the rate of overall HO and the rate of severe HO in high-risk patients. Randomized trials are needed to fully elucidate the potential benefit of XRT. PREPARE Clinical Trial Registration Number: NCT03523962.

Endoscopic Excision of Hip Heterotopic Ossification, Plus Indomethacin and Radiation, Is Effective in Treating and Preventing Recurrence

To describe the clinical and patient-reported outcomes of heterotopic ossification (HO) excision as well as the results of a standardized HO prophylaxis protocol among a group of patients who previously underwent open or arthroscopic hip surgery. Patients who developed HO after index hip surgery and were subsequently treated with arthroscopic excision of HO and postoperative HO prophylaxis using 2 weeks of indomethacin and radiation were retrospectively identified. All patients were seen by a single surgeon and were treated with the same arthroscopic technique. Patients were also placed on a regimen of 2 weeks of indomethacin 50 mg and radiation therapy with 700 cGy in one fraction on the first postoperative day. Outcomes assessed included recurrence of HO and conversion to total hip arthroplasty by latest follow-up. Other outcomes included Modified Harris Hip Scores and Non-Arthritic Hip Scores, which were collected preoperatively and at 1-year and 2-year follow-up. There were 5 female and 9 male subjects, with an average age of 39 years (range 22-66) and average body mass index of 27.1 (19.1-37.5). Average follow-up time was 46 months (range 4-136). No patients had experienced HO recurrence by latest follow-up. Only 2 patients converted to total hip arthroplasty, one at 6 months and the other at 11 months postexcision. Average outcome scores improved by 2-year follow-up (average Modified Harris Hip Scores 52.8 improved to 86.5, average Non-Arthritic Hip Scores 49.4 improved to 83.8). Minimally invasive arthroscopic excision of HO and postoperative prophylaxis with combined indomethacin and radiation therapy effectively treats and prevents the recurrence of HO. Level IV, case series, therapeutic.

Rectus Femoris Heterotopic Ossification: Combined Arthroscopic and Open Resection With Allograft Reconstruction and Concomitant Treatment of Femoroacetabular Impingement

Background: Heterotopic ossification (HO), or the abnormal formation of bone in extra-skeletal tissue, is a well-known complication of orthopedic trauma, tendon avulsions, chronic injuries, spinal cord injuries, and soft tissue damage from surgery. Heterotopic ossification commonly develops at the direct or indirect head of the rectus femoris. Athletes are especially susceptible to chronic microtearing and acute tendon avulsion, which may result in HO. When HO develops in the setting of concurrent intra-articular hip pathology, it may be amendable to arthroscopic excision, depending on its size and location. Indications: Heterotopic ossification that develops adjacent to the hip joint can affect range of motion of the joint and is often a source of pain. Arthroscopic excision is indicated when the HO that develops within or about the hip joint is symptomatic and is of a location and size that it can be reached and excised arthroscopically. Technique Description: In this technical note, we describe our method to excise HO using initial arthroscopic surgery to address femoroacetabular impingement syndrome (FAIS) and perform initial dissection of the HO fragment. Heterotopic ossification resection was then completed via an anterior open approach followed by reconstruction of the rectus femoris origin with Achilles allograft. This is followed by our HO prophylaxis protocol of indomethacin 75 mg daily for 4 days, followed by naproxen 500 mg 2 times daily through postoperative day 30, although many other regimens exist for HO prophylaxis. Results: Using arthroscopy for the removal of symptomatic HO at the time of surgery allows for the management of concomitant intra-articular pathology and efficient and precise dissection of the undersurface of the HO fragment. Discussion/Conclusion: Heterotopic ossification is a well-characterized complication of soft tissue damage, including tendon avulsion, trauma, previous surgery, and chronic microtear of the hip musculature. Oftentimes, HO develops in a location that can be reached arthroscopically. Surgeons should consider combining intra-articular arthroscopic surgery with arthroscopic excision of HO when appropriate, noting that there are many advantages to arthroscopic removal when compared with open procedures. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Heterotopic ossification prophylaxis after acetabular fracture fixation using a posterior approach: a retrospective study at a level 1 trauma center

Background: Heterotopic ossification (HO) is a known complication of acetabular fracture repair. After surgery, standard methods for HO prevention involve observation, radiation therapy, or a course of nonsteroidal antiinflammatories (indomethacin). Methods: A retrospective chart review was performed to analyze the effectiveness of radiation and indomethacin as HO prophylaxis after acetabular fracture surgical repair. Data were analyzed from 117 patients who underwent stabilization of the acetabulum utilizing a posterior approach from 2016 to 2020. Patients were classified into three groups based on the postoperative therapy received: radiation therapy, indomethacin therapy, or no prophylaxis. Grade of HO for each patient was determined by examining pelvic radiographs using the Brooker classification system at the most recent follow-up. Incidence of total and severe HO was recorded for each group and compared. Demographics, follow-up time, injury severity, and other trauma characteristics also were reported. Statistics were calculated using a combination of analysis of the variance (ANOVA), chi square, and Kruskal-Wallis testing. Results: The indomethacin group was younger than the other two groups with a shorter average follow-up time. The radiation group demonstrated a lower incidence of severe and total HO compared to the control group. The indomethacin group had significantly less total HO than the control group. Conclusions: With a decreased incidence of severe HO in the radiation group compared to no prophylaxis, this study supports the utility of radiation therapy as HO prophylaxis following acetabular fracture repair using a posterior approach. It shows a trend indicating that indomethacin also may be useful. Level of Evidence: Level III.

Surgical Resection Combined with Adjuvant Radiotherapy and Non-Steroidal Anti-Inflammatory Drugs in the Treatment of Heterotopic Ossification Following Total Hip Arthroplasty.

Heterotopic ossification (HO) is a well-known complication following total hip arthroplasty (THA), with an average incidence of 30%. Patients are classified according to Brooker's staging system. In advanced stages (III and IV), HO may limit hip motion and cause intolerable pain. For these symptomatic stages, surgical excision is mandatory, usually combined with prophylaxis of recurrence with non-steroidal anti-inflammatory drugs (NSAIDs) and/or radiotherapy. We present the case of a 70-year-old woman who developed Stage IV HO after undergoing THA for left hip osteoarthritis. Surgical excision of the HO was performed eighteen months after THA, with adjuvant radiotherapy and indomethacin. After two years of follow-up, the patient had a good hip function with no recurrence of HO. Several authors have studied the effect of NSAIDs and radiotherapy in HO prophylaxis and in HO treatment but there is lack of reports concerning the combination of the two strategies with surgery in the postoperative period. We therefore report this successful case of post-THA HO treatment with surgical excision and post-operative radiotherapy and NSAIDs.

Heterotopic Ossification in Burn Patients.

Heterotopic ossification (HO) is a known complication of burns. The incidence of this complication is low. The etiology is unclear, but experiment conducted about HO can be significant. Currently, there are still no targeted, effective preventive and therapeutic measures against it. In this study, the relevant literature is summarized to demonstrate the potential pathogenic mechanisms, diagnosis, prophylaxis, and treatment measures of HO in burn patients. Early diagnosis and treatment can be effective in improving the prognosis of patients.

Low-dose Preoperative Unshielded Radiation Is Effective in Heterotopic Ossification Prophylaxis and Does Not Affect Porous Fixation in Total Hip Arthroplasty at 2 Years Minimum Follow-up: A Radiographic Study.

Heterotopic ossification (HO) is a frequent complication of total hip arthroplasty (THA). HO can cause pain, limitation of range of motion, and instability. Radiation therapy (RT) for HO prophylaxis is well established but may interfere with early porous ingrowth and pullout strength of implants, as suggested by two animal studies. Although shielding of the bone from irradiation may theoretically protect ingrowth, it has been found to reduce RT effectiveness. Despite the popularity of porous implants in THA, the frequency of HO, and use of RT in its prophylaxis, the effect of RT on porous implant fixation in THA has not been previously reported. At our institution, we use unshielded, single-dose, preoperative 700 to 800 centigrays RT for HO prophylaxis in high-risk patients. We hypothesize that this RT protocol is effective and the press-fit technique protects porous implants during early ingrowth; therefore, long-term implant fixation is not compromised. This was a retrospective study aiming to determine fixation of porous THA implants, healing of trochanteric osteotomies, and efficacy of HO prophylaxis with this RT protocol. Thirty-nine patients with follow-up of 24 to 144 months (average 59.7 months) were included. All 26 porous-coated femoral implants (11 revisions and 15 primary) were well fixed. There were 33 porous-coated acetabular implants (18 revisions and 15 primary). Thirty (91%) were well fixed, and three revision implants (9%) demonstrated radiolucent lines in two zones, but patients were clinically asymptomatic. All nine trochanteric osteotomies healed uneventfully. RT provided effective HO prophylaxis in 33 of 39 hips (85%). Single, low-dose, preoperative RT without shielding does not increase aseptic loosening of porous implants manufactured with plasma porous spray or nonunion of extended trochanteric osteotomies. This protocol provides effective HO prophylaxis in high-risk patients undergoing primary and revision THA.

Heterotopic Ossification: Clinical Features, Basic Researches, and Mechanical Stimulations.

Heterotopic ossification (HO) is defined as the occurrence of extraskeletal bone in soft tissue. Although this pathological osteogenesis process involves the participation of osteoblasts and osteoclasts during the formation of bone structures, it differs from normal physiological osteogenesis in many features. In this article, the primary characteristics of heterotopic ossification are reviewed from both clinical and basic research perspectives, with a special highlight on the influence of mechanics on heterotopic ossification, which serves an important role in the prophylaxis and treatment of HO.