Incidence Of Heterotopic Ossification 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.

"Heterotopic ossification after total hip arthroplasty through direct anterior approach without a dedicated orthopaedic table or direct lateral approach: a quasi-randomized single-center study".

Heterotopic ossifications (HO) are common after total hip arthroplasty (THA). The invasiveness of surgical approaches plays a relevant role in HO development. The aims of this study were to assess the development of HO 6 months after THA through direct lateral approach (DLA) or direct anterior approach (DAA) without a dedicated orthopaedic table and to assess the clinical impact of HO. This is a single-center IRB-approved, quasi-randomized prospective cohort, observational imaging study. Fifty patients underwent primary THA through DLA and 50 through DAA. Age, sex, BMI and side of the affected hip were collected. At the 6 post-operative month the Harris Hip Score (HHS) and the presence of HO (scored through the Brooker classification system) were assessed. There was no significant difference in the demographic data between groups. Operative time was significantly higher in the DAA group (72 ± 10min vs. 58 ± 8min: p < 0.03). At 6 post-operative months the incidence of HO was 14% in the DAA group and 32% in the DLA group (p = 0.02). Severe HO (Brooker 3-4) were significantly more common in the DLA group (p = 0.04). There was no significant difference in the HHS of patients with HO between the DAA and DLA groups. There was no association between poorer clinical outcomes and the severity of HO. The DAA without a dedicated orthopaedic table is associated with a significant lower incidence of HO than the DLA 6 months after elective THA. Except for the surgical approach, no other factors correlated with the occurrence of HO. Even though a lower HHS was found with severe HO, the correlation between severity of HO and clinical outcomes did not reach statistical significance.

Heterotopic ossification following total hip arthroplasty. Which is the predominant risk factor: surgical approach or post-operative prophylaxis?

To investigate the impact of surgical approach and post-operative prophylaxis on heterotopic ossification (HO) development after total hip arthroplasty (THA). A retrospective analysis of 312 patients who underwent THA between January 2009 and April 2016. Patients were categorized by surgical approach (direct lateral or posterolateral), prosthesis type, and post-operative prophylaxis (Etoricoxib 60mg daily for two weeks). Two orthopaedic surgeons independently assessed radiographs at serial intervals, and HO was graded as per Brooker classification. Bivariate analysis and regression modelling were performed to assess the associations and confounding effects of different variables, RESULTS: Bivariate analysis identified factors correlated with higher HO incidence: absence of prophylaxis, older age, longer symptom evolution, and lower pre-surgery physical activity. Regression modelling showed a correlation between the direct-lateral approach, post-operative prophylaxis, symptom evolution, and higher HO incidence. Patients with longer symptom evolution before surgery and without post-operative prophylaxis are at higher risk of developing HO. While the direct lateral approach showed higher HO rates, the difference was insignificant. A two-week prophylactic regimen of Etoricoxib 60mg daily after THA effectively reduced HO formation. Pharmacological prophylaxis should be evaluated case-by-case, considering patient characteristics and risk factors.

Long-term outcomes of anterior cervical dynamic implants: motion-sparing or a delayed fusion?

Background ContextUse of an anterior cervical dynamic implant (ACDI) is generally considered a nonfusion technique for treating cervical degenerative disorders. However, there is limited research focused on evaluating the long-term clinical and radiographic outcomes of ACDI. PurposeTo analyze the long-term clinical and radiographic outcomes of ACDI in the treatment of degenerative cervical disorders. Study DesignA retrospective cohort study. Patients SamplePatients with degenerative cervical disorders who underwent anterior cervical discectomy and dynamic cervical implant (DCI) implantation between May 2012 and August 2020 at our institution were included in this study. Outcome MeasuresClinical outcomes were assessed using the modified Japanese Orthopedic Association (mJOA), visual analog scale (VAS) scores and patient reported satisfaction rate. Imaging assessment parameters included intervertebral height (IH), intervertebral disc height (IDH), C2-7 range of motion (ROM), segmental ROM, the degree of DCI subsidence and anterior migration, heterotopic ossification (HO) as well as adjacent segment degeneration (ASD). MethodsJOA and VAS scores were obtained through questionnaire. The patient reported satisfaction was rated as very satisfied, satisfied, less satisfied and dissatisfied at the final follow-up. The position of the implants, IDH and IH were evaluated on lateral radiographs. ROM at C2-7, ROM at operated level were measured on dynamic radiographs. Cervical 3 -dimensional computer tomography (CT) and magnetic resonance image (MRI) images were used to assess the presence of HO and ASD. The clinical and radiologic variables between the preoperative period and different follow-up time point were statistically analyzed by unpaired t-tests or chi-square tests. Statistical significance was defined as p<.05. ResultsA total of 92 patients (51 males and 41 females) were included in this study. Among them, there were 36 cases of cervical spondylotic myelopathy, 26 cases of cervical radiculopathy, and 30 cases of myeloradiculopathy. The mean age was 55.1±12.6 years. The number of operated levels was single level in 57 patients, 2 levels in 31 patients, and 3 levels in 4 patients. The average follow-up period was 81.3 months (range: 35-135 months). The mean JOA scores showed a gradual increase at 1 month, 1 year, and the final follow-up (12.0±0.7,13.5±0.8, and14.4±1.1 respectively) compared to the preoperative score (9.1±0.9, p<.01). VAS scores significantly decreased at 1 month, 1 year, and the final follow-up (4.1±0.7, 2.3±0.9, and 2.0±0.8 respectively) compared to the preoperative score (7.2±l .2, p<.01). At the final follow-up, the patient reported satisfaction was rated as very satisfied, satisfied, less satisfied and dissatisfied (79%, 10%, 10%, 1% respectively). Revision surgery was not required for any of the patients during the follow-up period, either due to instrumentation failure or adjacent segmental diseases. In the radiographic assessment, there was a notable increase in IH and IDH after surgery compared to preoperative values (33.0±4.0 mm vs. 30.7±3.0 mm, p<.01 and 6.7±2.4 mm vs. 4.6±0.9 mm, p<.01 respectively), which gradually decreased at 1 year and the final follow-up (IH: 32.1±2.5 vs. 30.9±3.5 p=.024; IDH: 5.3±1.5 mm vs. 4.3±0.6 mm, p=.043 respectively). At the 1-month postoperative follow-up, the segmental ROM exhibited a decrease compared with preoperative values (6.2±1.8° vs. 7.5±2.0° p=.044), followed by an increase at the 1-year follow-up (6.2±1.8° vs. 6.4±1.5° p=.078), but ultimately decreased at the final follow-up (6.4±1.5° vs. 2.9±0.6°, p<.01). HO was observed in approximately 81.5% of cases (75/92), while a great proportion (41.3%) of patients experienced varying degrees of prosthesis subsidence and anterior migration during the follow-up. ConclusionAt the long-term follow-up, a high incidence of HO, along with varying degrees of subsidence and migration of the prosthesis, were observed in most patients. As the motion preservation capability of the ACDI gradually diminishes, delayed intervertebral autofusion becomes a more likely outcome compared to motion sparing.

Clinical and Radiological Outcomes of Cervical Disc Arthroplasty in Patients with Modic Change.

Modic change (MC) is defined as abnormalities observed in the intervertebral disc subchondral and adjacent vertebral endplate subchondral bone changes. Most studies on MC were reported in the lumbar spine and associated with lower back pain. However, MC has been rarely reported in the cervical spine, let alone in those who underwent cervical disc replacement (CDR). This study aimed to focus on MC in the cervical spine and reveal clinical and radiological parameters, especially heterotopic ossification (HO), for patients who underwent CDR. Furthermore, we illustrated the association between MC and HO. We retrospectively reviewed patients who underwent CDA from January 2008 to December 2019. The Japanese Orthopaedic Association (JOA), Neck Disability Index (NDI), and Visual Analog Scale (VAS) scores were used to evaluate the clinical outcomes. Radiological evaluations were used to conclude the cervical alignment (CL) and range of motion (ROM) of C2-7, functional spinal unit angle (FSUA), shell angle (SA), FSU height, and HO. Univariate and multivariate logistic regressions were performed to identify the risk factors for HO. The Kaplan-Meier (K-M) method was used to analyze potential risk factors, and multivariate Cox regression was used to identify independent risk factors. A total of 139 patients were evaluated, with a mean follow-up time of 46.53 ± 26.60 months. Forty-nine patients were assigned to the MC group and 90 to the non-MC group. The incidence of MC was 35.3%, with type 2 being the most common. Clinical outcomes (JOA, NDI, VAS) showed no significant difference between the two groups. The differences in C2-7 ROM between the two groups were not significant, while the differences in SA ROM and FSUA ROM were significantly higher in the non-MC than in the MC group (p < 0.05). Besides, FSU height in MC group was significantly lower than that in non-MC group. Parameters concerning CL, including C2-7, FSUA, SA, were not significantly different between the two groups. The incidence of HO and high-grade HO, respectively, in the MC group was 83.7% and 30.6%, while that in the non-MC group was 53.3% and 2.2%, and such differences were significant (p < 0.05). Multivariate logistic regression analyses and Cox regression showed that MC and involved level were significantly associated with HO occurrence (p < 0.05). No implant migration and secondary surgery were observed. MC mainly affected the incidence of HO. Preoperative MC was significantly associated with HO formation after CDR and should be identified as a potential risk factor for HO. Rigorous criteria for MC should be taken into consideration when selecting appropriate candidates for CDR.

Emphasizing the Importance of Naproxen Prophylaxis May Decrease the Rate of Heterotopic Ossification After Hip Arthroscopy

To investigate the incidence of heterotopic ossification (HO) in patients prescribed prophylactic nonsteroidal anti-inflammatory drugs (NSAIDs), both before and after the introduction of a standardized education protocol. A retrospective review was conducted using a database of hip arthroscopy patients treated by a single surgeon at an academic hospital from 2015 to 2023. The inclusion criteria were (1) primary hip arthroscopy for the treatment of femoroacetabular impingement, (2) completion of a 2-week course of prophylactic postoperative NSAIDs (500 mg of naproxen twice daily), and (3) availability of follow-up radiographs at the 6-month postoperative visit. The control cohort was merely prescribed the postoperative prophylactic NSAIDs, whereas the intervention cohort also received dedicated in-person education, emphasizing the importance of NSAID adherence. The presence of HO was determined through review of follow-up radiographs. Standard descriptive statistics were used to describe the findings. Both the control and intervention groups consisted of 200 continuous hip arthroscopy patients, with the control group treated from 2015 to 2017 and the intervention group treated from 2020 to 2023. Within the control group, 10 cases of HO (5%) were detected. Within the intervention group, 2 cases of HO (1%) were found. The Pearson χ2 test with Yates continuity correction produced a value of 4.21, with a P value of .04. In this study, we found a significantly lower incidence rate of HO in patients who received standardized education on the importance of NSAID compliance versus those who did not. This finding suggests that patient education may play a contributory role in reducing the incidence of HO after hip arthroscopy. Level III, comparative cohort study.

Incidence of heterotopic ossification following total hip arthroplasty by approach: a systematic review.

Heterotopic ossification (HO) formation has been increasingly recognized as a complication of major orthopedic surgeries, particularly total hip arthroplasty (THA). Though, the overall incidence of HO following THA has been well-documented, it is often not reported by severity or by surgical approach. (1) What are the demographics of patients with HO? (2) What is the severity of HO following THA using the Brooker classification? (3) What is the incidence and class of HO following different THA approaches (anterior, posterior, posterolateral, anterolateral, superior, lateral, trans-gluteal)? (4) What are the number and training level of surgeons who performed each procedure? The PubMed, Embase, and Web of Science databases were queried, and PRISMA guidelines were followed. Qualitative and quantitative analyses were performed using Microsoft Excel. We isolated 26 studies evaluating 6512 total hip arthroplasties (THA). The mean HO percentage overall was 28.8%, mostly Class I (54.2%) or Class II (29.6%). The highest percentage of HO was associated with the modified direct lateral (57.2%) and the traditional lateral (34.6%) approaches. The lowest HO percentages were identified following posterolateral (12.8%) and direct superior approaches (1%). Most studies reported a singular senior surgeon operating within the same approach for all patients. The traditional lateral and modified direct lateral approaches to THA resulted in the highest percentage of HO postoperatively. However, most ossification cases were not clinically significant and did not strongly affect overall patient morbidity. Further studies are warranted to identify an association between severity of ossification and different arthroplasty approaches.

Incidence and risk factors of heterotopic ossification after cervical Baguera C disc arthroplasty.

This retrospective study was designed to evaluate the incidence and predisposing factors of heterotopic ossification (HO) after cervical disc arthroplasty (CDA) with a specific implant at 1 and 2 levels, and to investigate the biomechanical effects related to HO. The study goal was to identify ways to reduce the likelihood of HO formation after surgery. The study included patients who underwent only 1- or 2-level CDA with the Baguera C disc between November 2014 and December 2021 at a single medical center. All patients were operated on by the same neurosurgeon. The surgical indication included 1-level or 2-level disc herniation between C3 and C7 with radiculopathy, myelopathy, or both, with minimal spondylosis. The various factors were assessed by evaluating plain radiographs and cervical CT scans. The presence of HO was evaluated at different intervals postsurgery, and HO severity was graded using the McAfee classification. Of 107 patients who underwent CDA, 47 (43.9%) had HO at 63 of 171 levels (36.8%). Most cases with HO were grade 1, and no grade 4 was observed. Statistically significant risk factors for HO were the length of endplate coverage ratio and inferior anterior residual exposed endplate (AREE); sex, age, implant height and width, shell angle, and pre- and postoperative functional spinal unit (FSU) angle were not significant. More AREE and greater kyphotic postoperative FSU angle in the flexion position were significant factors differentiating HO grades 0 and 1 from grades 2 and 3. Furthermore, the non-HO group showed a trend of higher range of motion at any postoperative time compared to the HO group, especially at 1 month after surgery. The HO incidence after CDA was correlated with the residual length of endplate coverage and inferior AREE. Additionally, the AREE and kyphotic postoperative FSU angle in the flexion position were associated with HO grade progression. Patients with HO also showed a trend of lower range of motion at 1 month after surgery. Using an adequately sized implant and encouraging neck motion may help prevent HO development and progression.

Influence of preoperative symptom duration on effectiveness of cervical disc arthroplasty in cervical spondylotic radiculopathy patients

To investigate the influence of preoperative symptom duration on effectiveness of cervical disc arthroplasty (CDA) in cervical spondylotic radiculopathy (CSR) patients. The clinical data of 90 CSR patients who underwent single-segment CDA between January 2008 and March 2020 and met the selection criteria were retrospectively analyzed. Based on preoperative symptom duration, patients were divided into an early intervention group (preoperative symptom duration <24 months) and a late intervention group (preoperative symptom duration ≥24 months). There was no significant difference in baseline data between the two groups ( P>0.05), including age, gender, body mass index, smoking status, surgical segment, preoperative neck disability index (NDI), visual analogue scale (VAS) score, cervical lordosis (CL), C 2-C 7 range of motion (ROM), disc angle (DA), disc ROM (DROM), and disc intervertebral height (DIH). The early intervention group had a slightly higher preoperative Japan Orthopedic Association (JOA) score than the late intervention group ( P<0.05). Perioperative indicators such as operation time, intraoperative blood loss, and postoperative hospital stay were recorded. The changes of JOA score, NDI, and VAS score at last follow-up compared with those before operation were used to evaluate the clinical efficacy, and the imaging evaluation of CL, C 2-C 7 ROM, DA, DROM, and DIH was performed before operation, immediately after operation, and at last follow-up. The incidence of prosthesis-related complications, including heterotopic ossification (HO), anterior bone loss (ABL), and prosthesis subsidence, was also assessed at last follow-up. Patients in both groups were followed up 24-120 months, with an average of 53.4 months. There was no significant difference in operation time, intraoperative blood loss, or follow-up duration between the groups ( P>0.05). However, the late intervention group had significantly longer postoperative hospital stay compared to the early intervention group ( P<0.05). At last follow-up, there was no significant difference in the changes of JOA score, NDI, and VAS score between the two groups before and after operation ( P>0.05). During the follow-up, there was no surgical revision in the two groups, and there was no significant difference in the incidence of HO, ABL, and prosthesis subsidence between the two groups at last follow-up ( P>0.05). Imaging evaluation showed that there was no significant difference in CL, C 2-C 7 ROM, DA, DROM, and DIH between the two groups at each time point before and after operation ( P>0.05). The intra-group comparison showed that the early intervention group could maintain the immediate postoperative CL at last follow-up, while the late intervention group had recovered to the preoperative level. Additionally, the C 2-C 7 ROM, DROM, and DA had all recovered to preoperative levels at last follow-up in both groups; meanwhile, the DIH significantly increased immediately after operation and sustained until the last follow-up. Preoperative symptom duration significantly affects the effectiveness of CDA in CSR patients. Patients with preoperative symptom duration ≥24 months have longer postoperative hospital stays and potentially poorer ability to maintain CL compared with patients with preoperative symptom duration <24 months.

Sex as a Critical Variable in Basic and Pre-Clinical Studies of Fibrodysplasia Ossificans Progressiva.

Heterotopic ossification (HO) is most dramatically manifested in the rare and severely debilitating disease, fibrodysplasia ossificans progressiva (FOP), in which heterotopic bone progressively accumulates in skeletal muscles and associated soft tissues. The great majority of FOP cases are caused by a single amino acid substitution in the type 1 bone morphogenetic protein (BMP) receptor ACVR1, a mutation that imparts responsiveness to activin A. Although it is well-established that biological sex is a critical variable in a range of physiological and disease processes, the impact of sex on HO in animal models of FOP has not been explored. We show that female FOP mice exhibit both significantly greater and more variable HO responses after muscle injury. Additionally, the incidence of spontaneous HO was significantly greater in female mice. This sex dimorphism is not dependent on gonadally derived sex hormones, and reciprocal cell transplantations indicate that apparent differences in osteogenic activity are intrinsic to the sex of the transplanted cells. By circumventing the absolute requirement for activin A using an agonist of mutant ACVR1, we show that the female-specific response to muscle injury or BMP2 implantation is dependent on activin A. These data identify sex as a critical variable in basic and pre-clinical studies of FOP.

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.

Prevalence and clinical implications of heterotopic ossification after distal biceps tendon repair.

Complete distal biceps tendon ruptures are relatively uncommon. Conservative treatment may result in persistent pain and weakness. Therefore, surgical repair is usually indicated in order to restore strength. Different surgical techniques and fixation methods have been described. The most reported complications after surgery are iatrogenic nerve damage, heterotopic ossification (HO) and re-rupture. Heterotopic ossification can be variable in size. Significant HO can limit range of motion while minor HO often remains asymptomatic. The overall presence of HO is likely underreported in literature, as imaging is reserved for symptomatic patients. The purpose of this study is to report the prevalence and clinical implications of heterotopic ossification after surgical repair of the distal biceps tendon. This retrospective study assessed the prevalence and clinical relevance of postoperative HO after distal biceps tendon repair. CT-scans were used to evaluate size and location of the HO. VAS scores, DASH scores, MEPI, and range of motion (ROM) were assessed to evaluate pain, patient satisfaction and elbow function. HO was observed on CT images of 19 out of 35 patients (54%). The use of interference screws, timing of surgery after rupture and timing of radiographic assessment postoperatively did not influence the prevalence of HO. The presence of HO had no statistically significant impact on the VAS scores, ROM measurements and MEPI and DASH scores. According to our findings, the overall incidence of HO is higher than previously reported but there are no differences in clinical outcomes when compared to patients without HO.

The Incidence of Heterotopic Ossification in Surgically and Non-surgically Treated Elbow Fractures at a Municipal Hospital in Japan.

Background: Heterotopic ossification (HO) is a well-recognised complication of after elbow trauma. The prevalence and risk factors of HO have been previously reported. However, these reports were based on elbow trauma that had undergone surgical treatment and most of them were from Western countries. This study aimed to assess the incidence of HO in patients with elbow fractures who were treated surgically and non-surgically in Japan. Methods: We retrospectively identified consecutive patients who were treated of elbow fractures and fracture-dislocations at our institution in recent consecutive 3-year periods. We extracted patient demographics, injury mechanisms and treatment details from the medical records. Furthermore, we reviewed radiographs to classify the fracture pattern and identify the presence or absence of HO. Results: HO was identified in 6/97 (6%) patients. Fracture-dislocation was noted in 4/6 patients. The fracture types with HO included terrible triad injury (n = 2), isolated coronoid process fractures (n = 2), distal humerus A-type fractures (n = 1) and radial head fracture (n = 1). According to the Hastings and Graham classification, HO was classified as Class I in five patients and Class II B in one patient who underwent additional surgery for HO resection. Conclusions: The incidence of HO was relatively low in our patients. However, of the 20 conservatively treated elbows, one patient developed clinically relevant HO and required excision of HO. Even patients with elbow fractures treated conservatively should be informed of the potential risk of developing severe HO requiring surgical excision. In addition, surgeons in this region could use these data to inform patients about the risk of HO development after an elbow injury. Level of Evidence: Level IV (Therapeutic).

Incidence of Heterotopic Ossification at 10 years After Cervical Disk Replacement: A Systematic Review and Meta-analysis.

Systematic review and meta-analysis. This study aimed to assess the incidence of heterotopic ossification (HO) 10 years after cervical disk replacement (CDR). HO is a common complication after CDR and may limit the range of motion of the artificial disk. As HO usually progresses slowly, a long-term follow-up is required to better understand its incidence. In recent years, the increasing number of original articles reporting 10-year outcomes gives us the opportunity to better understand the long-term incidence of HO. We searched PubMed, Medline, Embase, and Cochrane Library databases to identify eligible studies. The incidence of HO was pooled, and subgroup analysis was performed. Meta-regression analyses were conducted to identify factors contributing to heterogeneity. Eleven studies with at least 10 years of follow-up comprising 1140 patients who underwent CDR were included. The pooled incidence of overall HO was 70% (95% CI, 60%-81%) at 10 years postoperatively, 60% (95% CI, 44%-75%) at five or six years postoperatively, and 50% (95% CI, 27%-72%) at one or two years postoperatively. The pooled incidence of severe HO (grade 3 or 4) was 37% (95% CI, 29%-45%), and mild HO (grade 1 to 2) was 30% (95% CI, 17%-44%) at 10 years of follow-up. Pooled range of motion decreased from 8.59° before surgery to 7.40° 10 years after surgery. Subgroup analysis showed that HO incidence differed according to the prosthesis type. The earlier publication was associated with a higher pooled incidence of severe HO in the meta-regression analysis. This is the first meta-analysis providing detailed information on the pooled 10-year incidence of HO after CDR. The incidence of HO seems to increase with the length of follow-up. 3.

A Short Course of Celecoxib Prevents Heterotopic Ossification Following Cementless Total Hip Arthroplasty.

Heterotopic ossification (HO) is a common complication after total hip arthroplasty (THA) and can result in pain and loss of motion of the hip. This is the first study in the literature to determine if a short course of Celecoxib is effective in the prevention of HO in patients undergoing cementless THA. In this retrospective study of prospectively collected data, consecutive patients undergoing a primary cementless THA were reviewed at a 2-year follow-up. The Control group consisted of 104 hips that did not receive Celecoxib (Control group), while the 208 hips in the Celecoxib group received 100 mg twice daily for 10 days. Radiographs, patient-recorded outcome measures and range of motion (ROM) were evaluated. Overall, there was a significantly decreased incidence of HO in the Celecoxib group (18.7%) than in the Control group (31.7%) (p = 0.01). The odds that a patient developed HO using Celecoxib were 0.4965 times the odds that a patient developed HO without treatment. Clinically, the Celecoxib group demonstrated significantly greater improvement in their mean WOMAC stiffness (0.35 vs. 0.17, p = 0.02) and physical function scores (3.26 vs. 1.83, p = 0.03) compared to those in the Control group, but there was no difference in the ROM between the two groups. This study is the first to demonstrate that the lowest dose of Celecoxib for a short course of only 10 days is a simple and effective prophylactic treatment option that can significantly reduce the incidence of HO following cementless THA.

Comparison of Postoperative Complications Between Trochanter Flip Osteotomy and Kocher-Langenbeck Approaches for the Treatment of Femoral Head Fractures: A Systematic Review and Meta-analysis.

The study aims to identify the optimal approach for femoral head fracture (FHF) by comparing the postoperative complications and outcome score of the Kocher-Langenbeck posterior approach (KLP) and trochanteric flip osteotomy (TFO) through a systematic review and meta-analysis. MEDLINE, Embase and the Cochrane Library were systematically searched for studies published up to 22 January 2023, which compared TFO to the KLP for FHF treatment. The main outcomes of this meta-analysis were the rate of postoperative complications including osteonecrosis of the femoral head (ONFH), heterotopic ossification (HO), and total hip replacement (THR) conversion rate and Thompson-Epstein (T-E) score at the final follow-up. We included four studies with 57 cases of FHFs; 27 and 30 patients underwent TFO and the KLP, respectively. Following the pooled analysis, HO incidence was significantly higher in TFO than in the KLP (OR = 4.03; 95% CI 1.10-14.81; P = 0.04; I 2 = 0%), but there were no differences in other variables, including the incidence of ONFH (OR = 0.41; 95% CI 0.07-2.35; P = 0.32; I 2 = 0%), THR conversion rate (OR = 0.82; 95% CI 0.16-4.29; P = 0.81; I 2 = 0%), and number of inferior results in the T-E score (OR = 0.49; 95% CI 0.14-1.73; P = 0.27; I 2 = 0%). Amongst the posterior approaches for FHFs, the KLP and TFO did not present significant clinical and radiological differences; hence, the approach can be selected depending on the surgeon's experience and preference.

The development of a mouse model to investigate the formation of heterotopic ossification.

Muscle injury and concomitant bone injury are important drivers to induce heterotopic ossification (HO). However, the related roles of muscle and concomitant bone injury in HO formation are still unclear. This study aims to develop a mouse model through the combination of hindlimb amputation (Am) and cardiotoxin (CTX) injection to investigate the mechanism of HO formation. The mice were randomly divided into Am group (Am of right hindlimb, n = 12), CTX group (CTX injection in the calf muscle of left hindlimb, n = 12) and Am + CTX group (the combination of Am of right hindlimb and CTX injection of left hindlimb, n = 18). MicroCT was used to evaluate the incidence of HO. Histology was used to investigate the progression of HO. The MicroCT showed that only Am or CTX injection failed to induce HO while the combination of Am and CTX injection successfully induced HO. The incidence of HO was significant in Am + CTX group on day 7 (0% vs 0% vs 83.3%, p = 0.001) and day 14 (0% vs 0% vs 83.3%, p = 0.048). HO was located on the left hindlimb where CTX was injected. Moreover, the bone volume and bone density on day 14 were higher than those on day 7 in Am + CTX group. Histology revealed the evidence of calcification and expression of osteogenic markers in calcification sites in Am + CTX group. In summary, the combination of Am and CTX injection could successfully induce dystrophic calcification/HO, which occurs in the location of muscle injury.

Low-dose prophylaxis protocol for heterotopic ossification after hip preservation surgery in a sport participants cohort.

Heterotopic ossification (HO) is a well-known complication of arthroscopic and open surgical treatment of femoroacetabular impingement (FAI). Incidence of heterotopic ossification has been reported in the literature between 0% and 44% after hip arthroscopy and between 18.2% and 25% after anterior mini-open surgery. Currently, pharmacological prophylaxis with NSAIDs and selective COX-2 inhibitors are commonly used and their effectiveness is well documented in literature. We hypothesized that the low-dose prophylaxis protocol with selective cox-2 inhibitors decreases the risk of heterotopic ossification in open or arthroscopic hip preservation surgery in athletes. This study is an analysis of prospectively gathered data on 98 sport participant patients who underwent arthroscopic or anterior mini-open treatment for FAI between April 2008 and April 2018. All the patients received postoperative oral prophylaxis with 60mg etoricoxib once daily for two weeks. Post-operative X-rays were performed at 1, 3, and 12 months after surgery and reviewed by two orthopedic surgeons blinded to the type and side of surgery. HO were graded according to the Brooker classification. Descriptive statistics was used to analyze demographic data. Bivariate analysis was performed to analyze the association of HO with each of the following variables: type of surgery, physical activity, time of evolution of symptoms, age at surgery, and sex. Finally, a regression model analysis was performed to determine the presence of confounding effects between variables. The study cohort was composed of 54 patients in the arthroscopic treatment group and 44 patients in the anterior mini-open group. HO was identified in 6 (13.6%) patients in the mini-open group. No HO was identified in the arthroscopic group. In the bivariate analysis, "type of surgery" was the only variable that showed a statistically significant association with HO (p=0.007). Results of this study suggest that anterior mini-open treatment was characterized by a higher risk of HO development compared to hip arthroscopy for femoroacetabular impingement treatment regardless of pharmacological prophylaxis. The treatment regimen of 60 mg etoricoxib daily for two weeks was an effective prophylaxis for HO formation in sport participant patients compared with data available in the literature.

Severe Quadriceps Heterotopic Ossification after Knee Revision Arthroplasty in a 42-Year-Old Suffering from Rheumatoid Arthritis: A Case Report

Background: Heterotopic Ossification (HO) of the knee is most commonly formed anteriorly to the distal femoral shaft in the quadriceps expansion. Although the incidence of severe HO with large dimensions affecting the knee and resulting in severe consequences is extremely rare, these cases are extremely difficult to prevent and have severe clinical limitations for the patient. Aim: The purpose of this study was to present and explore HO formation after Total Knee Arthroplasty (TKA). Conclusions: It is crucial to perform a stratification of patients for the risk of HO formation after TKA and to gain a better understanding of the fundamental role of post-operative treatments. In severe HO, surgery should be considered following appropriate investigations and should only be considered when the HO has fully matured. In comparison to Total Hip Arthroplasty (THA), HO formation after TKA is less frequent and underexplored. Therefore, further studies are required. This case report can represent a protocol for the treatment of clinically relevant HO in the knee after TKA.

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.