Research trends and hotspots of myositis ossificans: a bibliometric analysis from 1993 to 2022.

Myositis ossificans (MO) is characterized by benign heterotopic ossificans in soft tissues like muscles, which can be classified into nonhereditary MO and fibrodysplasia ossificans progressiva (FOP). Although MO has been studied for decades, no research reviewed and analyzed the features of publications in this field quantitatively and qualitatively. Using bibliometrics tools (bibliometrix R package, VOSviewer, and CiteSpace), we conducted a bibliometric analysis of 1280 articles regarding MO in the Web of Science Core Collection database from 1993 to 2022. The annual number of publications and related research areas in the MO field increased gradually in the past 20 years. The USA contributed the most percentage (42.58%) of articles. The University of Pennsylvania (UPenn) and the Journal Bone published the most articles among all institutions and journals. Kaplan FS and Shore EM from UPenn were the top two scholars who made the largest contributions to this field. Keyword analysis showed that research hotspots changed from traumatic MO and clinical management of MO to the genetic etiology, pathogenesis, and treatment of FOP. This study can provide new insights into the research trends of MO and helps researchers grasp and determine future study directions more easily.

A Novel Surgical Technique for the Management of Large-Volume Neurogenic Heterotopic Ossification Following a Spinal Cord Injury: The Sashimi Technique.

This case series investigates the efficacy of the "sashimi technique," a novel surgical approach utilizing a curved chisel for the resection of heterotopic ossification (HO). The main focus is on reducing resection margins and preventing excessive bone removal while maintaining optimal functional outcomes and preventing recurrence. Two cases illustrate successful outcomes in patients with spinal cord injuries and severe HO of the hip, emphasizing the precision of using the curved chisel-based technique in improving patient mobility while still achieving a desired resection margin. The study highlights the effectiveness of using a curved chisel in protecting neurovascular structures and maintaining resection precision. Additionally, the integration of postoperative radiotherapy and pharmacological treatment is emphasized as a strategy to prevent recurrence. The goal of this procedure is to improve functional outcomes and patient quality of life.

Post-Traumatic Radio-ulnar Synostosis Managed by the Excision of the Bone Bridge and Palmaris Longus Encircling Loop over the Ulna: A Case Report.

Introduction: Radioulnar synostosis is an uncommon complication of forearm fractures and presents with varying degrees of restricted forearm movement. The diaphysial distal third synostosis is less common and excision of the synostosis is fraught with risk of re-ossification. Use of inert or biological interposing material has thus been accompanied with the synostosis excision and various methods have been described. There is still no consensus on the ideal treatment method. Case Report: We, hereby, report a case of a long-standing radioulnar synostosis with rotational restriction of movement. Despite the movement restriction, the patient could perform basic activities of daily living and wanted to improve the movements. The presence of diaphyseal radioulnar synostosis was conformed on the radiographs and computerized tomography scan. A volar forearm approach was used and the bony bridge was excised. The ipsilateral native palmaris longus (PL) tendon was extracted from distal wrist crease and with its proximal attachment intact, circumferentially wrapped around the ulnar raw surface as an interposing material. Apart from this, free fat was also placed at the synostosis site. In the long-term follow-up of 10 years, there was no radiological evidence of re-ossification noted. The clinical improvement was not much but the patient was performing activities of daily living with no discomfort. Conclusion: The use of an encircling loop of the native PL tendon, over the raw surface of one of the forearm bones, may be another useful method to decrease the chances of recurrence following the excision of the synostosis.

Delayed femoral artery injury caused by heterotopic ossification: a rare case report and review of the literature.

BACKGROUND: Arterial injury caused by heterotopic ossification (HO) following fractures is rarely reported, yet it can have catastrophic consequences. This case report presents a unique instance of femoral artery injury and hematoma organization, occurring a decade after intramedullary nail fixation for a femoral shaft fracture complicated by HO. CASE PRESENTATION: A 56-year-old male presented with right femoral artery injury and organized hematoma, a decade after suffering bilateral femoral shaft fractures with mild head injury in a traffic accident. He had received intramedullary nailing for the right femoral shaft fracture and plate fixation for the left side in a local hospital. Physical examination revealed two firm, palpable masses with clear boundaries, limited mobility, and no tenderness. Peripheral arterial pulses were intact. Radiography demonstrated satisfactory fracture healing, while a continuous high-density shadow was evident along the inner and posterior aspect of the right thigh. Computed tomography angiography identified a large mixed-density mass (16.8 × 14.8 × 20.7 cm) on the right thigh's medial side, featuring central calcification and multiple internal calcifications. The right deep femoral artery coursed within this mass, with a smaller lesion noted on the posterior thigh. Surgical consultation with a vascular surgeon led to planned intervention. The smaller mass was completely excised, but the larger one partially, as it encased the femoral artery. The inability to remove all HO was due to excessive bleeding. Postoperatively, the patient experienced no complications, and one-year follow-up revealed a favorable recovery with restoration of full right lower limb mobility. CONCLUSION: This case underscores the potential gravity of vascular injury associated with heterotopic ossification. Surgeons should remain vigilant regarding the risk of vascular injury during HO excision.

Personalizing Prophylactic Radiotherapy for Hip Heterotopic Ossification: An AMSTAR-2 Compliant Review of Meta-analyses.

BACKGROUND/AIM: Heterotopic ossification (HO) is a common complication following total hip arthroplasty. Various prophylactic treatments have been proposed, including radiotherapy (RT). This review summarizes the evidence from meta-analyses on the efficacy of RT in preventing hip HO. MATERIALS AND METHODS: A literature search was conducted on PubMed. The quality of the meta-analyses was assessed using the AMSTAR-2 tool. RESULTS: Seven meta-analyses were included. One meta-analysis reported a significant reduction in HO occurrence after RT compared to the control group. Comparing RT and non-steroidal anti-inflammatory drugs, one and two meta-analyses showed significantly greater efficacy of RT in preventing severe HO and better outcomes in patients receiving drugs, respectively. Regarding RT settings, the postoperative and preoperative RT were each supported by one meta-analysis. Furthermore, two meta-analyses showed an advantage of multi-fractionated RT over single fraction RT. The overall confidence rate of the meta-analyses was moderate, low, and critically low in one, three, and three meta-analyses, respectively. CONCLUSION: RT is a confirmed prophylactic intervention for HO. However, the precise optimization of timing, dosage, and fractionation requires elucidation. Future research should focus on the development of predictive models through large-scale data collection and advanced analytics to refine individualized treatment strategies and assess RT comparative effectiveness with drugs.

Disturbed glycolipid metabolism activates CXCL13-CXCR5 axis in senescent TSCs to promote heterotopic ossification.

Heterotopic ossification (HO) occurs as a common complication after injury, while its risk factor and mechanism remain unclear, which restricts the development of pharmacological treatment. Clinical research suggests that diabetes mellitus (DM) patients are prone to developing HO in the tendon, but solid evidence and mechanical research are still needed. Here, we combined the clinical samples and the DM mice model to identify that disordered glycolipid metabolism aggravates the senescence of tendon-derived stem cells (TSCs) and promotes osteogenic differentiation. Then, combining the RNA-seq results of the aging tendon, we detected the abnormally activated autocrine CXCL13-CXCR5 axis in TSCs cultured in a high fat, high glucose (HFHG) environment and also in the aged tendon. Genetic inhibition of CXCL13 successfully alleviated HO formation in DM mice, providing a potential therapeutic target for suppressing HO formation in DM patients after trauma or surgery.

Development and validation of a nomogram for predicting heterotopic ossification following spinal cord injury.

OBJECTIVE: Heterotopic ossification (HO) following spinal cord injury (SCI) can severely compromise patient mobility and quality of life. Precise identification of SCI patients at an elevated risk for HO is crucial for implementing early clinical interventions. While the literature presents diverse correlations between HO onset and purported risk factors, the development of a predictive model to quantify these risks is likely to bolster preventive approaches. This study is designed to develop and validate a nomogram-based predictive model that estimates the likelihood of HO in SCI patients, utilizing recognized risk factors to expedite clinical decision-making processes. METHODS: We recruited a total of 145 patients with SCI and presenting with HO who were hospitalized at the China Rehabilitation Research Center, Beijing Boai Hospital, from June 2016 to December 2022. Additionally, 337 patients with SCI without HO were included as controls. Comprehensive data were collected for all study participants, and subsequently, the dataset was randomly partitioned into training and validation groups. Using Least Absolute Shrinkage and Selection Operator regression, variables were meticulously screened during the pretreatment phase to formulate the predictive model. The efficacy of the model was then assessed using metrics including receiver-operating characteristic (ROC) analysis, calibration assessment, and decision curve analysis. RESULTS: The final prediction model incorporated age, sex, complete spinal cord injury status, spasm occurrence, and presence of deep vein thrombosis (DVT). Notably, the model exhibited commendable performance in both the training and validation groups, as evidenced by areas under the ROC curve (AUCs) of 0.756 and 0.738, respectively. These values surpassed the AUCs obtained for single variables, namely age (0.636), sex (0.589), complete spinal cord injury (0.681), spasm occurrence (0.563), and DVT presence (0.590). Furthermore, the calibration curve illustrated a congruence between the predicted and actual outcomes, indicating the high accuracy of the model. The decision curve analysis indicated substantial net benefits associated with the application of the model, thereby underscoring its practical utility. CONCLUSIONS: HO following SCI correlates with several identifiable risk factors, including male gender, youthful age, complete SCI, spasm occurrence and DVT. Our predictive model effectively estimates the likelihood of HO development by leveraging these factors, assisting physicians in identifying patients at high risk. Subsequently, correct positioning to prevent spasm-related deformities and educating healthcare providers on safe lower limb mobilization techniques are crucial to minimize muscle injury risks from rapid iliopsoas muscle extension. Additionally, the importance of early DVT prevention through routine screening and anticoagulation is emphasized to further reduce the incidence of HO.

A scoping review on active vs. passive range of motion approaches to treat heterotopic ossification at the elbow.

Objective: The objective of this scoping review is to synthesize and clarify literature on the effectiveness of active and passive range of motion therapy techniques to address range of motion in people with heterotopic ossification (HO), and to provide guidance to therapists in clinical decision-making based on current evidence. Method: To find articles that included therapeutic interventions to maintain or improve range of motion in people with heterotopic ossification, the authors searched the following databases: Cochrane Database of Systematic Reviews, PubMed, CINAHL, PsychINFO, Web of Science, and OTSeeker. To ensure that the search was comprehensive, the authors also searched Burns and Trauma, Burns Journal, Burns Open, and the Journal of Hand Therapy. Searches were limited to peer-reviewed articles published in the English language. No publication date limits were set. The Physiotherapy Evidence Database PEDro scale was utilized to measure the validity of the methodological quality of each article. Results: Five studies met the inclusion criteria.. Two studies emphasized that passive range of motion was effective in less than 50% of their subjects, while the other three studies utilized active range of motion only, reporting 50% of patients did not require surgery. Discussion/conclusion: There is insufficient evidence to determine effective therapeutic management of HO and the literature that does exist is contradictory and inconclusive. Future research is necessary to determine if any effectiveness of manual therapeutic approaches exists for patients with HO.

Ossification of the posterior longitudinal ligament is linked to heterotopic ossification of the ankle/foot tendons.

INTRODUCTION: Systemic osteogenesis has been speculated to be involved in the pathogenesis of ossification of the posterior longitudinal ligament (OPLL). Our purpose was to compare the radiologic prevalence and severity of heterotopic ossification in foot tendons of Japanese patients with OPLL and to determine their association with systemic heterotopic ossification. MATERIALS AND METHODS: Clinical and radiographic data of 114 patients with OPLL were collected from 2020 to 2022. Control data were extracted from a medical database of 362 patients with ankle radiographs. Achilles and plantar tendon ossification were classified as grades 0-4, and the presence of osteophytes at five sites in the foot/ankle joint was assessed by radiography. Factors associated with the presence and severity of each ossification were evaluated by multivariable logistic regression and linear regression analysis. RESULTS: The prevalence of Achilles and plantar tendon ossification (grade ≥ 2) was 4.0-5.5 times higher in patients with OPLL (40-56%) than in the controls (10-11%). The presence of Achilles tendon ossification was associated with OPLL, age, and coexisting plantar tendon ossification, and was most strongly associated with OPLL (standardized regression coefficient, 0.79; 95% confidence interval, 1.34-2.38). The severity of Achilles and plantar tendon ossification was associated with the severity of ossification of the entire spinal ligament. CONCLUSIONS: The strong association of foot tendon ossification with OPLL suggests that patients with OPLL have a systemic osteogenesis background. These findings will provide a basis for exploring new treatment strategies for OPLL, including control of metabolic abnormalities.

AMPK induces PIAS3 mediated SUMOylation of E3 ubiquitin ligase Smurf1 impairing osteogenic differentiation and traumatic heterotopic ossification.

AMP-activated protein kinase (AMPK) is a typical sensor of intracellular energy metabolism. Our previous study revealed the role of activated AMPK in the suppression of osteogenic differentiation and traumatic heterotopic ossification, but the underlying mechanism remains poorly understood. The E3 ubiquitin ligase Smurf1 is a crucial regulator of osteogenic differentiation and bone formation. We report here that Smurf1 is primarily SUMOylated at a C-terminal lysine residue (K324), which enhances its activity, facilitating ALK2 proteolysis and subsequent bone morphogenetic protein (BMP) signaling pathway inhibition. Furthermore, SUMOylation of the SUMO E3 ligase PIAS3 and Smurf1 SUMOylation was suppressed during the osteogenic differentiation and traumatic heterotopic ossification. More importantly, we found that AMPK activation enhances the SUMOylation of Smurf1, which is mediated by PIAS3 and increases the association between PIAS3 and AMPK. Overall, our study revealed that Smurf1 can be SUMOylated by PIAS3, Furthermore, Smurf1 SUMOylation mediates osteogenic differentiation and traumatic heterotopic ossification through suppression of the BMP signaling pathway. This study revealed that promotion of Smurf1 SUMOylation by AMPK activation may be implicated in traumatic heterotopic ossification treatment.

Angiogenesis in heterotopic ossification: From mechanisms to clinical significance.

Heterotopic ossification (HO) refers to the formation of pathologic bone in nonskeletal tissues (including muscles, tendons or other soft tissues). HO typically occurs after a severe injury and can occur in any part of the body. HO lesions are highly vascularized. Angiogenesis, which is the formation of new blood vessels, plays an important role in the pathophysiology of HO. Surgical resection is considered an effective treatment for HO. However, it is difficult to completely remove new vessels, which can lead to the recurrence of HO and is often accompanied by significant problems such as intraoperative hemorrhage, demonstrating the important role of angiogenesis in HO. Here, we broadly summarize the current understanding of how angiogenesis contributes to HO; in particular, we focus on new insights into the cellular and signaling mechanisms underlying HO angiogenesis. We also review the development and current challenges associated with antiangiogenic therapy for HO.

Long term use of interleukin-1 inhibitors reduce flare activity in patients with fibrodysplasia ossificans progressiva.

OBJECTIVES: Fibrodysplasia ossificans progressiva (FOP) is one of the most catastrophic forms of genetic heterotopic ossification (HO). FOP is characterized by severe, progressive inflammatory flare-ups, that often lead to HO. The flare-ups are associated with increased inflammatory cytokine production, suggesting auto-inflammatory features driven by interleukin-1ß (IL-1ß). This study describes the short- and long-term responses of FOP patients to anti-IL-1 therapy. METHODS: Previously, we reported that a patient with FOP treated with anti-IL-1 agents showed dramatically lower rates of flare-ups, improved flare-up symptoms, decreased use of glucocorticoids, and apparently decreased size of residual lesions. Plasma analyses also showed marked elevation in IL-1ß levels during a FOP flare, further supporting a role of IL-1ß in the pathogenesis of FOP flares. Here, we report results from long-term therapy with IL-1 inhibitors in that patient, and describe 3 additional patients, from two medical centers. RESULTS: All 4 patients showed persistent improvement in flare activity during treatment with IL-1 inhibitors, with minimal formation of new HO sites. Two patients who stopped therapy experienced resurgence of flare activity that was re-suppressed upon re-initiation. These patients had IL-1ß levels comparable to those in IL-1ß-driven diseases. Child Health Assessment Questionnaires confirmed extensive subjective improvements in the pain and general health visual analogue scales. CONCLUSION: This case series demonstrates significant benefits from IL-1 inhibitors for reducing flare activity and improving the general health of patients with FOP. These data provide strong support for additional studies to better understand the function of IL-1 inhibition, primarily in reducing formation new HO. FUNDING: RH received support from the International FOP Association ACT grant; ECH received support from NIH/NIAMS R01AR073015 and the UCSF Robert Kroc Chair in Connective Tissue and Rheumatic Diseases III.

Fibrodysplasia ossificans progressiva: Two case reports.

Fibrodysplasia ossificans progressiva (FOP) is a rare and progressively debilitating disorder affecting 1 in 2 million individuals. It is characterized by the progressive ossification of soft tissues into ectopic bone and congenital malformations of the great toes. FOP leads to significant disability and can result in death due to thoracic insufficiency syndrome. These case reports examine the presentation, diagnosis, and management of FOP, highlighting the diagnostic challenges inherent in managing such rare conditions because of their unique clinical features. They underscore the need for increased awareness among healthcare practitioners to ensure early diagnosis and the implementation of effective management strategies.

Exploring the Link Between Autophagy-Lysosomal Dysfunction and Early Heterotopic Ossification in Tendons.

Heterotopic ossification (HO), the pathological formation of bone within soft tissues such as tendon and muscle, is a notable complication resulting from severe injury. While soft tissue injury is necessary for HO development, the specific molecular pathology responsible for trauma-induced HO remains a mystery. The previous study detected abnormal autophagy function in the early stages of tendon HO. Nevertheless, it remains to be determined whether autophagy governs the process of HO generation. Here, trauma-induced tendon HO model is used to investigate the relationship between autophagy and tendon calcification. In the early stages of tenotomy, it is observed that autophagic flux is significantly impaired and that blocking autophagic flux promoted the development of more rampant calcification. Moreover, Gt(ROSA)26sor transgenic mouse model experiments disclosed lysosomal acid dysfunction as chief reason behind impaired autophagic flux. Stimulating V-ATPase activity reinstated both lysosomal acid functioning and autophagic flux, thereby reversing tendon HO. This present study demonstrates that autophagy-lysosomal dysfunction triggers HO in the stages of tendon injury, with potential therapeutic targeting implications for HO.

Heterotopic ossification following COVID-19 infections: systematic literature review of case reports and case series.

BACKGROUND: This review aims to study the clinical characteristics, diagnostic results, treatments, and outcomes in patients with heterotopic ossification following COVID-19 infection. METHODS: A literature search for eligible articles was conducted using MEDLINE/Pubmed, Global Health, and Scopus databases (January 12th, 2023), including all case reports and case series from any country and language. The criteria for inclusion in this review were cases of COVID-19 infection subsequently developing heterotopic ossification. RESULTS: This systematic review analysed 15 reports (n = 20 patients) documenting cases of heterotopic ossification following COVID-19 infection. 80% of the patients were male, with a median age of 59 years. All patients required intensive care unit stay with an average duration of 48.5 days. Mechanical ventilation was necessary for all patients and 30% of them underwent tracheostomy. Common symptoms included stiffness and pain, most frequently affecting multiple locations (70%), with the hips and shoulders being predominantly involved. X-rays were the most commonly used imaging modality, followed by computed tomography. Although treatment was given, some of the patients continued to experience symptoms, particularly stiffness. CONCLUSION: 20 patients who developed heterotopic ossification after COVID-19 have been reported, the majority of which had at least two independent risk factors for this condition. The link between those two clinical entities is therefore uncertain, requiring further investigation. It is nonetheless important to suspect heterotopic ossification in patients with severe COVID-19 infection, prolonged immobilisation, mechanical ventilation, who develop joint pain and stiffness, as this condition can significantly impact patients' quality of life. PROTOCOL REGISTRATION: CRD42023393516.

Posttraumatic Compressive Neuropathy of the Deep Motor Branch of the Ulnar Nerve Caused by Heterotopic Ossification.

We report a case of posttraumatic compressive neuropathy of the deep motor branch of the ulnar nerve occurring in the setting of heterotopic ossification following a direct blow to the hypothenar eminence. Over several weeks, the patient developed ring and little finger claw deformities and atrophy of his first dorsal interosseous and adductor pollicis muscles with sparing of sensation. Electromyography and nerve conduction study localized the area of injury, and computed tomography confirmed the presence of heterotopic bone near the deep motor branch of the ulnar nerve. Intraoperatively, the deep motor branch of the ulnar nerve was under tension as it traversed volarly over the hook of hamate and heterotopic bone. Decompression of the deep motor branch of the ulnar nerve with resection of heterotopic bone and the hook of hamate was performed. Six months postoperatively, the patient demonstrated resolution of clawing and improving strength of his ulnar nerve innervated intrinsic muscles.

Suppression of TNF-α activity by immobilization rescues Mkx expression and attenuates tendon ossification in a mouse Achilles tenotomy model.

Traumatic heterotopic ossification is a condition in which extraskeletal bone formation occurs in soft tissues after injury. It most commonly occurs in patients who had major orthopedic surgery and in those with severe extremity injuries. The lesion causes local pain and can impair motor function of the affected limb, but there is currently no established prophylaxis or treatment for this condition. In this study, we show that immobilization at an early stage of the inflammatory response after injury can attenuate ossification formation in a murine Achilles tenotomy model. Gene expression analysis revealed a decrease in the expression of Tnf and an increase in the expression of Mkx, which encodes one of the master regulators of tendon differentiation, Mohawk. Notably, we found that TNF-α suppressed the expression of Mkx transcripts and accelerated the osteogenic differentiation of tendon-derived mesenchymal stem cells (MSCs), suggesting that TNF-α acts as a negative regulator of Mkx transcription. Consistent with these findings, pharmaceutical inhibition of TNF-α increased the expression of Mkx transcripts and suppressed bone formation in this mouse model. These findings reveal the previously unrecognized involvement of TNF-α in regulating tendon MSC fate through suppression of Mkx expression and suggest that TNF-α is a potential target for preventing traumatic heterotopic ossification.

Posttraumatic proximal radioulnar synostosis: Current concepts on the clinical presentations, classifications, and open surgical approaches.

In the forearm, posttraumatic heterotopic ossification usually forms as a proximal radioulnar synostosis. It can occur after soft tissue injury involving the interosseous membrane or after surgery involving the radio and ulna, such as distal biceps tendon repair. It can also be induced by radial head dislocation or fracture. Screening radiography can be used to select the appropriate time for excision. The synostosis can be resected when the ectopic bone margin and trabeculation appear mature on radiographs. An interval of 6-12 months from the injury is generally recommended based on ectopic bone maturity. Selection of the surgical approach depends on site, extension (elbow joint or proximal radioulnar joint), severity of the initial articular surface, and periarticular tissue injury. The posterolateral approach is indicated for synostoses: at or distal to the bicipital tuberosity, at the level of the radial head, and proximal radioulnar joint. The posterior global approach is recommended when the forearm synostosis is associated with complete bony ankylosis of the elbow involving the distal aspect of the humerus. After surgical resection of a proximal radioulnar synostosis, the exposed bone surfaces can be covered with interposition material to minimize recurrence.

Genetic regulation of injury-induced heterotopic ossification in adult zebrafish.

Heterotopic ossification is the inappropriate formation of bone in soft tissues of the body. It can manifest spontaneously in rare genetic conditions or as a response to injury, known as acquired heterotopic ossification. There are several experimental models for studying acquired heterotopic ossification from different sources of damage. However, their tenuous mechanistic relevance to the human condition, invasive and laborious nature and/or lack of amenability to chemical and genetic screens, limit their utility. To address these limitations, we developed a simple zebrafish injury model that manifests heterotopic ossification with high penetrance in response to clinically emulating injuries, as observed in human myositis ossificans traumatica. Using this model, we defined the transcriptional response to trauma, identifying differentially regulated genes. Mutant analyses revealed that an increase in the activity of the potassium channel Kcnk5b potentiates injury response, whereas loss of function of the interleukin 11 receptor paralogue (Il11ra) resulted in a drastically reduced ossification response. Based on these findings, we postulate that enhanced ionic signalling, specifically through Kcnk5b, regulates the intensity of the skeletogenic injury response, which, in part, requires immune response regulated by Il11ra.

A case report of heterotopic ossifications in abdominal incision scar.

INTRODUCTION: Heterotopic ossification (HO) develops when bone formation appears in soft tissues, usually after an injury or major surgery. Timely and accurately diagnosing of this rare event is essential due to the possibility of misdiagnosis as a maintained foreign body, infection, incisional neoplastic recurrence, and metastatic or primary neoplasms. CASE PRESENTATION: In this study, we present a 57-year-old man who was operated for peritonitis due to perforated appendicitis, and an asymptomatic HO was accidentally found on an incisional line of previous open prostatectomy about 5 years earlier due to benign prostatic hyperplasia. A bone density lesion was seen in the fascia and on the incisional scar of previous surgery. DISCUSSION: HO rarely occurs within an abdominal incision due to surgery. It is reported only within vertical midline incisions and mainly within the first year after the operation. Imaging confirms the diagnosis of HO in previous abdominal surgery scars, which reveals dense vertical calcification along the previous incisional scar. In the case of HO, the exclusive effective management is the entire surgical excision with primary closure, and NSAIDs are the preventive choices. CONCLUSION: HO should be considered in patients presenting with discomfort or palpable mass or even asymptomatic patients with previous abdominal surgeries besides considering relative history such as surgical complications or neoplasms.