A rare case of extensive neurogenic heterotopic ossification: a case report.

INTRODUCTION: Neurogenic Heterotopic ossification (NHO) is a potential sequalae and a detrimental complication following neurological insult. It is characterized by formation of localized gradually progressive, peri-articular lamellar bone formation in extra-skeletal tissues. We would like to report a rare case of heterotopic ossification involving all 4 limbs, in which we tried to restore joint mobility to improve his functional status so that he could perform his daily tasks. CASE PRESENTATION: We present a case of a 33-year-old bed ridden male, diagnosed with NHO involving all 4 limbs (bilateral hip, right knee, right shoulder, left elbow). The patient had a crippled posture, significant pain and impaired range of motion hampering movement of all four limbs which prevented him from lying down supine, sitting, walking and performing activities of daily living. After three surgeries, the patient achieved wheelchair mobilization and upright posture with the assistance of calipers. CONCLUSION: The management of NHO requires a multidisciplinary approach involving orthopaedic surgeons, neurologists & rehabilitation specialists. Prognosis of NHO depends on factors such as extent of ossification, underlying neurological condition & patients overall health.

Heterotopic Ossification of Bilateral Hips Post-COVID-19 and Prolonged Immobilization: A Case Report.

CASE: A 43-year-old healthy man developed hip pain post-coronavirus disease 2019 (COVID-19) immobilization. Imaging confirmed bilateral bridging heterotopic ossification (HO) of the hips, Brooker Class IV. Bilateral HO caused functional arthrodesis (45° flexion: -20° internal rotation). Bilateral HO resection resulted in almost full mobility at 1-year follow-up (90° flexion; 30° internal rotation). CONCLUSION: Many cases of HO after immobilization for COVID-19 have been reported, but as far as we know, this is the first case report describing surgical intervention as an adequate treatment option for severe restricted mobility caused by HO due to COVID-19-induced prolonged immobilization. Caution and preoperative 3D planning are recommended of HO formation near neurovascular structures.

Arthroscopic debridement improves range of motion for heterotopic ossification after total knee replacement: a retrospective cohort study.

The presence of heterotopic ossification (HO) after primary total knee replacement (TKR) is rare and associated with limited mobility and stiffness of the knee. This study aimed to identify if the arthroscopic debridement after TKR could decrease HO and improve the function and range of motion. Thirty HO patients after TKR were retrospectively separated into 2 cohorts. 15 patients of group A accepted the arthroscopic debridement, while 15 patients of group B only had non-operative treatment, mainly including oral nonsteroidal anti-inflammatory drugs (NSAIDs) and rehabilitative treatment. Visual analog scale (VAS) scores, knee society knee scores (KSS), range of motion (knee flexion and knee extension) were obtained before treatment and at 1 month, 3 months, and 6 months after treatment. Radiography of after-treatment was also evaluated to assess the changes in HO. There were 3 males and 27 females with a mean age of 67.4 ± 0.8 years in group A and 68.2 ± 1.3 in group B. The onset time of HO was 3-6 months. The maximum size of the ossification was < 2 cm in 23 knees, 2 cm < heterotopic bone < 5 cm in 6 knees and > 5 cm in 1 knee. The size of HO decreased gradually in all knees by X-ray film at the last follow-up. There were no significant differences in VAS scores after replacement between two groups (p > 0.05). The average range of motion preoperatively in group A was - 15.2-90.6°, which postoperatively increased to - 4.2-110.0°. Meanwhile, the KSS scores and average range of motion of the group A were better than those of the group B at each follow-up time after treatment. Arthroscopic debridement can decrease HO seen from postoperative X-rays, improve the function and range of motion, as well as the pain remission between two groups are comparable. Consequently, arthroscopic resection of HO after TKR is recommended as soon as there is aggravating joint stiffness.

Healing an ischial tuberosity pressure ulcer in a patient with neurogenic heterotopic ossification: a case report.

Neurogenic heterotopic ossification (NHO) is widely recognised as an aberrant bone formation in soft tissue following central nervous system injury. It is most frequently associated with pain and limited movement, especially in the hip. However, it may be neglected in patients with paraplegia with a pressure ulcer (PU). We report the case of an 18-year-old male patient who presented with a hard-to-heal ischial tuberosity PU and who had undergone three operations at other hospitals during the previous six months, which had failed to repair the PU. There was a history of paraplegia as a consequence of spinal cord injury two years previously. Computed tomography and three-dimensional reconstruction showed massive heterotopic ossification (HO) in the wound bed and around the right hip. Histological findings were consistent with a diagnosis of HO. The HO around the wound was completely excised, negative pressure wound therapy was used to promote granulation, and a gluteus maximus musculocutaneous flap was used to cover the wound. We conclude that for patients with paraplegia, with a hard-to-heal PU, it should be determined whether it is associated with NHO. Surgical resection of HO surrounding the wound and improving the microcirculation are critical for repair and reconstruction of these PUs.

3D-Printed Model in Preoperative Planning of Sciatic Nerve Decompression Because of Heterotopic Ossification: A Case Report.

CASE: A 31-year-old patient presented with an encapsulated sciatic nerve secondary to extensive hip heterotopic ossification (HO), which prevented visualization of a safe osteotomy site to avoid nerve damage. The 3D-printed model demonstrated an easily identifiable osseous reference point along the inferior aspect of the heterotopic mass, allowing for a vertical osteotomy to be safely performed. CONCLUSION: HO is associated with loss of normal anatomic topography. The current case report illustrates the use of a 3D-printed model to identify pertinent anatomic landmarks required for safe decompression of an encapsulated sciatic nerve within the anatomic region of the hip.

Heterotopic ossification, osteolysis and implant failure following cervical total disc replacement with the M6-C™ artificial disc.

INTRODUCTION: A recent study reported a 34% mid-term revision rate after M6-C™ cervical total disc replacement (CTDR) for wear-related osteolysis. Here, we aim to investigate the prevalence, risk factors, and radiographic characteristics of periprosthetic bony changes and implant failure of the M6-C™ artificial disc. METHODS: We retrospectively analysed radiographic (conventional X-ray, CT scan) and clinical outcomes (EQ-5D-5L, Neck Disability Index (NDI), and Visual Analog Scale (VAS) for neck and arm pain) data collected during routine follow-up of patients who underwent CTDR with the M6-C™ between 2011 and 2015. RESULTS: In total, 85 patients underwent CTDR with the M6-C™. Follow-up data were available for 43 patients (54% female, mean age 44 years) with 50 implants and a mean follow-up of 8.1 years (6.5-11 years). Implant failure with the presence of severe osteolysis was identified in 5 (12%) patients who were all male (p = 0.016) and implanted at the C5/6 level (p = 0.11). All failed implants required revision surgery. The overall prevalence of osteolysis was 44% (22/50 implants) and 34% (17/50 implants) for significant heterotopic ossification. Patients with high-grade osteolysis showed higher VAS arm pain (p = 0.05) and lower EQ-5D-VAS health VAS (p = 0.03). CONCLUSION: We report a lower reoperation rate for failed M6-C™ implants than previously published, but confirmed that osteolysis and heterotopic ossification are common following CTDR with the M6-C™ and may be asymptomatic. Therefore, we strongly recommend ongoing clinical and radiographic monitoring after CTDR with the M6-C™, particularly for male patients implanted at the C5/6 level.

Incidence and Risk Factors of Heterotopic Ossification in the Knee After Reamed Tibial Nailing.

INTRODUCTION: Heterotopic ossification (HO) in the knee after tibial intramedullary nailing (IMN) has yet to be thoroughly investigated. Our aim was to assess frequency and associated factors for HO in the knee after tibial IMN. METHODS: This is a retrospective review at a single level 1 urban trauma center of 213 patients who underwent reamed tibial IMN. Plain radiographs were reviewed postoperatively and on final follow-up (≥6 weeks). Chart review was performed for surgical approach (suprapatellar versus infrapatellar), demographics, injury characteristics, and clinical follow-up. The primary outcome was frequency of HO. RESULTS: HO on final follow-up (mean: 41.43 weeks) was recorded in 15% cases. Postsurgical retroinfrapatellar reaming debris (odds ratio [OR], 4.73), Injury Severity Score (OR, 1.05), intensive care unit admission (OR, 2.89), chest injury (OR, 3.4), and ipsilateral retrograde femoral IMN (OR, 5.08) showed a notable association with HO development. No association was observed in HO formation between surgical approach, knee pain, or range-of-motion deficits. DISCUSSION: Radiographic evidence of HO in the knee after reamed tibial IMN is not uncommon and is associated with retained reaming debris, Injury Severity Score, chest injury, intensive care unit admission, and ipsilateral retrograde femoral nailing. No differences were noted in HO formation between approaches. HO was not associated with knee pain or range-of-motion deficits.

Regional distribution prevalence of heterotopic ossification in the elbow joint: a 3D study of patients after surgery for traumatic elbow injury.

BACKGROUND: Heterotopic ossification (HO) is a common complication after elbow fracture surgery and can lead to severe upper extremity disability. The radiographic localization of postoperative HO has been reported previously. However, there is no literature examining the distribution of postoperative HO at the three-dimensional (3D) level. This study aimed to investigate 1) the distribution characteristics of postoperative HO and 2) the possible risk factors affecting the severity of postoperative HO at a 3D level. METHODS: A retrospective review was conducted of patients who presented to our institution with HO secondary to elbow fracture between 13 January 2020 and 16 February 2023. Computed tomography scans of 56 elbows before elbow release surgery were reconstructed in 3D. HO was identified using density thresholds combined with manual identification and segmentation. The elbow joint and HO were divided into six regions according to three planes: the transepicondylar plane, the lateral ridge of the trochlear plane, and the radiocapitellar joint and coronoid facet plane. The differences in the volume of regional HO associated with different initial injuries were analyzed. RESULTS: Postoperative HO was predominantly present in the medial aspect of the capsule in 52 patients (93%), in the lateral aspect of the capsule in 45 patients (80%), in the medial supracondylar in 32 patients (57%), and in the lateral supracondylar, radial head, and ulnar region in the same number of 28 patients (50%). The median and interquartile range volume of total postoperative HO was 1683 (777-4894) mm3. The median and interquartile range volume of regional postoperative HO were: 584 (121-1454) mm3 at medial aspect of capsule, 207 (5-568) mm3 at lateral aspect of capsule, 25 (0-449) mm3 at medial supracondylar, 1 (0-288) at lateral supracondylar, 2 (0-478) at proximal radius and 7 (0-203) mm3 at the proximal ulna. In the subgroups with Injury Severity Score > or = 16, Gustilo-Anderson II, normal uric acid levels, elevated alkaline phosphatase, and body mass index > or = 24, the median HO volume exceeds that of the respective control groups. CONCLUSION: The medial aspect of the capsule was the area with the highest frequency and median volume of postoperative HO among all initial elbow injury types. Patients with higher Gustilo-Anderson grade, Injury Severity Score, alkaline phosphatase or Body Mass Index had higher median volume of postoperative HO.

Eagle Syndrome: An Unusual Cause of Axial Neck Pain: A Case Report.

CASE: A 42-year-old woman presented with left-sided axial neck pain with radiation behind left ear of 3 months unresponsive to conservative treatment. As clinical examination revealed tenderness anterior to the mastoid process, she was referred to an otolaryngologist. Computed tomography showed an elongated left styloid process. Diagnostic local anesthetic infiltration provided complete pain relief confirming the diagnosis of Eagle syndrome (ES) after which a transoral excision of the left styloid process was performed. She was asymptomatic till the final follow-up of 15 months. CONCLUSION: ES should be considered in differential diagnosis of axial neck pain radiating to ear, and excision of the styloid process in resistant cases provides complete pain relief.

Heterotopic hip ossification resection: monocentric experiences of associated factors, outcomes, and complications.

PURPOSE: The exponential increase in total hip arthroplasty (THA) has led to acute and chronic surgery-related complications. Common chronic and local complications are represented by hip ossification (HO). The aim of our study was to assess the clinical and radiological correlates of patients undergoing surgical removal of heterotopic ossifications after THA and the possible association between HO and prosthetic joint infection. METHODS: Data of 26 patients who underwent surgical removal of periprosthetic calcifications after THA from 2000 to 2022 were analyzed and compared with characteristics of 156 subjects without HO. RESULTS: The preoperative radiographs of patients showed a high-grade Brooker, 3 or 4, later reduced to 1 or 2 in the postoperative radiographs. Ten (38.5%) patients underwent radiotherapy prophylaxis, administered as a single dose 24 h before surgery. In 19 (73%) patients, pharmacological prophylaxis with indomethacin was added in the 30 postoperative days. Only one patient who underwent radiotherapy had a recurrence, while new ossifications were found in three patients without prophylaxis (11.5%). Intraoperative cultures were performed for suspected periprosthetic infection in 8 study group patients. In logistic regression, the presence of HO was significantly and inversely associated with the ASA score (OR = 0.27, 95% CI = 0.09-0.82; P = 0.021) after adjusting. CONCLUSION: Surgical HO removal in symptomatic patients with high-grade disease produces good clinical and radiographic results. Radiotherapy was a good perioperative and preventive strategy for recurrence, also associated with NSAIDs and COX-2 inhibitors.

A fibrodysplasia ossificans progressiva patient with a rare missense mutation in ACVR1 detected on 18F-FDG PET/CT.

Fibrodysplasia ossificans progressiva (FOP) is an exceedingly rare human genetic disorder characterized by the progressive and incapacitating formation of ectopic bone outside the skeleton. We report a case of FOP patient with mutations within the ACVR1 gene (c.982G>A; p.G328R). 18F-FDG positron emission tomography/computed tomography (PET/CT) was carried out for disease assessment. Previous studies have shown increased FDG uptake in regions of heterotopic ossification (HO) in FOP. However, in our study, the PET/CT features demonstrate that active ossificans exhibit increased 18F-FDG uptake, whereas end-stage ossifications do not. Collectively, 18F-FDG PET/CT emerges as a prospective approach to evaluate medication efficacy in the early stages, directing early intervention and pharmacological management of FOP before ossifications formation.

Heterotopic bone formation with extramedullary haematopoiesis in a thyroid nodule.

The presence of mature bone and bone marrow in the thyroid gland is an exceedingly rare occurrence. Extramedullary haematopoiesis (EMH) and heterotopic bone formation (HBF) should be suspected when cytology of thyroid nodules reveals evidence of megakaryocytes or bone marrow fat, respectively. The cause of these abnormalities has not been fully elucidated, but the role of bone morphogenic factors (BMPs) in their pathogenesis has been suggested. Both EMH and HBF can be seen in both benign and malignant primary thyroid conditions, and although they have not been definitively associated with significant pathology, it is recommended that extension studies be considered in the event of these findings to rule out concomitant haematological conditions.

Effectiveness of topical sodium thiosulfate for ectopic calcifications and ossifications. Results of the CATSS-O study.

INTRODUCTION: Ectopic calcifications (ECs) and heterotopic ossifications (HOs) form in non-mineralized tissues, most often in subcutaneous and muscular areas. Local and systemic complications can cause severe disability. Systemic administration of sodium thiosulfate (STS) gives promising results but is difficult to use in clinical practice. OBJECTIVE: Evaluation of the efficacy and safety of topical STS in ECs and HOs. METHODS: Retrospective analysis of the CATSS-O registry that included patients receiving topical STS 25 % prepared by the pharmacy of Limoges hospital during 2014-2020. The efficacy of STS was assessed by imaging (radiography or CT) after at least 6 months' treatment. RESULTS: Among 126 patients who received STS 25 %, 35 had complete clinical and radiographic data for analysis (28 with ECs and 7 with HOs; 18 children [mean age 8.9 years, range 1.5-16], 17 adults [mean age 52.4 years, range 24-90]). Calcifications or ossifications were due to dermatomyositis (8 children, 6 adults), systemic scleroderma (6 adults) or pseudo-hypoparathyroidism 1A (7 children). They were single (37.1 %) or multiple (62.9 %). Treated regions were in the lower limbs (31.4 %), upper limbs (37.1 %) or both (28.6 %) and the axial region (2.9 %). Topical STS was clinically effective in 9/28 (32.1 %) patients with ECs and 2/7 (28.6 %) children with HOs. Three patients experienced complete disappearance of their calcifications. Response for ECs was better in children than adults (54.5% vs 17.6 %, p = 0.035). Topical STS was well tolerated. CONCLUSION: Local STS seems effective for ossifications, particularly pediatric calcifications or ossifications. Randomized and experimental studies are needed to confirm this observation and to identify the underlying mechanisms.

Endometrial Osseous Metaplasia-A Rare Cause of Infertility with Unknown Etiology.

Background: Osseous tissue in the endometrium is a rare find, and it is most often discovered when the patient presents with infertility. It is frequently associated with dysmenorrhea and abnormal menstrual bleedings. Although its etiology remains unclear, in almost all described cases until now, the patient has an obstetrical history. Case report: In this report, we present a unique case of endometrial osseous metaplasia in a 27-year-old primary infertile patient. The transvaginal ultrasound revealed a 18/13/7 mm hyperechoic endometrial mass with posterior acoustic shadowing and no flow on color Doppler. A hysteroscopic examination found a polygonal calcification on the endometrial posterior face of the uterine cavity, in the corporeal isthmic region, which was extracted. The histopathological evaluation revealed microscopic elements compatible with endometrial calcification. The patient had a good postoperative course and the complex endocrinologic, immunologic and electrolytical investigation failed to prove any abnormality. Follow-up transvaginal ultrasound examinations revealed no modifications. Three years later, the patient conceived spontaneously, had an uneventful pregnancy and delivered a full-term fetus. Conclusion: We assumed that this entity can be a serious cause of infertility since the patient had a long history of (primary) infertility and its resection made the pregnancy's occurrence possible. Finally, since neither history of abortion or chronic inflammation nor any abnormal laboratory test were noticed, we concluded that the etiology of this entity remained unclear.

Not All Osteophytes Are Located on the Right Side of the Vertebrae in Diffuse Idiopathic Skeletal Hyperostosis: A Quantitative Analysis in Relation to the Position of Aorta.

OBJECTIVE: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by osteophytes in the anterior vertebrae, and the presence of aorta may have an impact on their formation. However, the anatomical positional relationship between the aorta and osteophytes in patients with DISH remains controversial. This study aimed to evaluate the position of osteophytes in relation to aorta in DISH, and the influence of aortic pulsation on the formation of osteophytes from the perspective of morphology. METHODS: We conducted a retrospective review of 101 patients diagnosed with DISH and symptomatic lumbar spinal stenosis between June 2018 and December 2021. A total of 637 segments with heterotopic ossification in DISH were used for quantitative measurements on CT scans. The Cartesian coordinate system was built up on the axial CT scans to reflect the relative position between aorta and osteophytes. Osteophytes were divided into adjacent aorta group (AD group) and non-adjacent aorta group (N-AD group). In terms of the morphology, osteophytes in the AD group were further divided into convex, flat, and concave types. The relative position between aorta and osteophytes, and the aorta-osteophyte distance and morphology of osteophytes were compared. Univariate analysis of variance was performed for multiple groups, and two independent-samples t-tests were used for two groups. RESULTS: From T5 to L4, aorta gradually descended from left side to middle of vertebrae, and osteophytes gradually shifted from right side of vertebrae (T5-T10) to bilateral sides (T11-L4). Of 637 osteophytes in DISH, 60.1% (383/637) were in AD group, including convex type 0.6% (4/637), flat type 34.7% (221/637), and concave type 24.8% (158/637). The N-AD group accounted for 39.9% (254/637). Flat osteophytes were concentrated in T5-T12, while concave osteophytes in T11-L4. Overall, the aorta-osteophyte distance of concave type was significantly smaller than that of flat type. CONCLUSION: Osteophytes are not always located on the right side of vertebrae, but move with the position of the descending aorta. Furthermore, the morphology of osteophytes varies by vertebral segment in DISH, which is related to aorta descending anteriorly in the spine.

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

CASE: 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. CONCLUSION: 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.

Ulnar nerve neuropathy caused by pathologic ossification: a case report.

PURPOSE: Cubital tunnel syndrome is a well-described entity with many reported etiologies and anatomical compression sites. Accessory ossicles of either traumatic or congenital origin might occur around the elbow joint. Only one case reporting such ossicles compressing the ulnar nerve exists in previous literature. We aim to present this entity with a detailed description of the patient history and treatment. CASE REPORT: We report a case of 30-year-old female presenting with classical signs of cubital tunnel syndrome-positive Wartenberg's and Froment's signs, hypoesthesia in the fourth and fifth finger with decreased finger duction strength but without gross hypotrophy of interosseous and hypothenar muscles. Tinel's sign was positive over the ulnar sulcus and an accessory ossicle was found on the elbow radiograph within the ulnar sulcus. The first signs of calcification in this patient were reported 6 years prior in a follow-up after the dislocation of her elbow joint following a bike accident. The EMG confirmed ulnar nerve neuropathy in the elbow area. The ossicle was extirpated, the ulnar nerve was decompressed in the ulnar sulcus in a standard manner and the symptoms quickly resolved. The patient has been regularly visiting our outpatient clinic for the next 12 years without any complaints considering her elbow and the ulnar nerve. CONCLUSION: This is a rare case of cubital tunnel syndrome caused by an accessory ossicle of traumatic origin. Simple bone extirpation with ulnar nerve release followed by anterior subcutaneous transposition is the recommended method of treatment. No report of congenital accessory bones causing ulnar nerve compression in the elbow exists in the literature.