Preoperative Arterial Embolization for Heterotopic Ossification of the Hip.

PURPOSE: To investigate the efficacy and safety of preoperative arterial embolization for neurogenic heterotopic ossification (NHO) of the hip. MATERIALS AND METHODS: This single-center retrospective study reviewed outcomes in 16 consecutive patients who had surgical resection of NHO of the hip: 8 of whom underwent preoperative arterial embolization and 8 of whom did not. Both patient cohorts had similar baseline characteristics. A mean of 2.62 ± 1.9 arteries per patient, including the gluteal, lateral circumflex femoral, and deep circumflex iliac branches, were embolized using an n-butyl cyanoacrylate (NBCA)-ethiodized oil mixture. Data from both cohorts regarding intraoperative blood loss, volume of blood transfused, complications, and duration of hospitalization were compared. RESULTS: A mean of 2.6 ± 1.9 arteries were embolized with NBCA-ethiodized oil, mainly the gluteal arteries, lateral circumflex femoral artery, and deep circumflex iliac artery. In the embolization group, mean intraoperative blood loss was 875 mL ± 320, mean number of units of blood used was 0.5 ± 0.7, and mean number of days of hospitalization was 6.4 days ± 1.6. In the control group, mean intraoperative blood loss was 1,350 mL ± 120, mean number of units of blood used was 2 ± 1.1, and average number of days of hospitalization was 11.5 days ± 1.4. The embolization group had a mean reduction in blood loss of 40.7% (P = 0.035), reduction in units of blood administered of 75% (P = 0.021), and reduction in days of hospitalization of 44.7% (P = 0.014). No procedural complications were recorded. CONCLUSIONS: Preoperative arterial embolization is effective and safe in reducing intraoperative blood loss, number of hospitalization days, and need for blood transfusions in surgical resection of NHO of the hip.

Heterotopic Ossification of the Xiphoid After Chest Compressions.

This report describes the case of a 56-year-old woman with a 6-year history of severe epigastric pain after chest compressions for cardiac arrest. A comprehensive gastrointestinal workup was negative. However, an abdominal computed tomographic scan demonstrated an elongated xiphoid process. After a xiphoid trigger point injection, she experienced pain relief lasting 4 days, and thus her symptoms were attributed to xiphoidalgia secondary to heterotopic ossification after trauma. She underwent open resection of the xiphoid process. Heterotopic ossification of the xiphoid process is rare. This report documents a case of heterotopic ossification secondary to trauma from chest compressions.

Early local delivery of vancomycin suppresses ectopic bone formation in a rat model of trauma-induced heterotopic ossification.

Heterotopic ossification (HO) is a debilitating sequela of high-energy injuries. It frequently requires surgical excision once symptomatic and there is no practical prophylaxis for combat-injured patients. In this study, we examined the effect of local vancomycin powder on HO formation in a small animal model of blast-related, post-traumatic HO. Male Sprague-Dawley rats were subjected to a polytraumatic extremity injury and amputation with or without methicillin-resistant Staphylococcus aureus infection. Animals were randomized to receive a single local application of vancomycin (20 mg/kg) at the time of injury (POD-0, n = 34) or on postoperative day-3 (POD-3, n = 11). Quantitative volumetric measurement of ectopic bone was calculated at 12-weeks post-injury by micro-CT. Bone marrow and muscle tissues were also collected to determine the bacterial burden. Blood for serum cytokine analysis was collected at baseline and post-injury. Vancomycin treatment on POD-0 suppressed HO formation by 86% and prevented bone marrow and soft tissue infections. We concurrently observed a marked reduction histologically in nonviable tissue, chronic inflammatory cell infiltrates, bone infection, fibrous tissue, and areas of bone necrosis within this same cohort. Delayed treatment was significantly less efficacious. Neither treatment had a marked effect on the production of pro-inflammatory cytokines. Our study demonstrates that local vancomycin treatment at the time of injury significantly reduces HO formation in both the presence and absence of infection, with decreased efficacy if not given early. These findings further support the concept that the therapeutic window for prophylaxis is narrow, highlighting the need to develop early treatment strategies for clinical management. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2397-2406, 2017.

Delivery vehicle effects on bone regeneration and heterotopic ossification induced by high dose BMP-2.

Bone morphogenetic protein-2 (BMP-2), delivered on absorbable collagen sponge, is frequently used to treat bone defects. However, supraphysiological BMP-2 doses are common and often associated with complications such as heterotopic ossification and inflammation, causing pain and impaired mobility. This has prompted investigations into strategies to spatially control bone regeneration, for example growth factor delivery in appropriate scaffolds. Our objective was to investigate the spatiotemporal effects of high dose BMP-2 on bone regeneration as a function of the delivery vehicle. We hypothesized that an alginate delivery system would spatially restrict bone formation compared to a collagen sponge delivery system. In vitro, BMP-2 release was accelerated from collagen sponge compared to alginate constructs. In vivo, bone regeneration was evaluated over 12weeks in critically sized rat femoral segmental defects treated with 30µg rhBMP-2 in alginate hydrogel or collagen sponge, surrounded by perforated nanofiber meshes. Total bone volume, calculated from micro-CT reconstructions, was higher in the alginate group at 12weeks. Though bone volume within the central defect region was greater in the alginate group at 8 and 12weeks, heterotopic bone volume was similar between groups. Likewise, mechanical properties from ex vivo torsional testing were comparable between groups. Histology corroborated these findings and revealed heterotopic mineralization at 2weeks post-surgery in both groups. Overall, this study recapitulated the heterotopic ossification associated with high dose BMP-2 delivery, and demonstrated that the amount and spatial pattern of bone formation was dependent on the delivery matrix. STATEMENT OF SIGNIFICANCE: Alginate hydrogel-based BMP-2 delivery has induced better spatiotemporal bone regeneration in animals, compared to clinically used collagen sponge, at lower BMP-2 doses. Lack of clear dose-response relationships for BMP-2 vis-à-vis bone regeneration has contributed to the use of higher doses clinically. We investigated the potential of the alginate system, with comparatively favorable BMP-2 release-kinetics, to reduce heterotopic ossification and promote bone regeneration, when used with a high BMP-2 dose. While defect mineralization improved with alginate hydrogel, the initial high-release phase and likely early tissue exposure to BMP-2 appeared sufficient to induce heterotopic ossification. The characterization presented here should provide the framework for future evaluations of strategies to optimize bone formation and minimize adverse effects of high dose BMP-2 therapy.

Periarticular infiltration in total hip replacement: effect on heterotopic ossification, analgesic requirements and outcome.

BACKGROUND: Up to 80% of patients develop heterotopic ossification (HO) following total hip replacement (THR) and high grades may adversely affect outcome. This study investigated the influence of local infiltration of a NSAID (Ketorolac) and local anaesthetic on the incidence and grade of HO following THR, the effect on post-operative opiate analgesic requirement and on patient reported outcome score. METHODS: A retrospective study was performed on 118 THRs performed without periarticular infiltration from 2003 to 2005, and on 211 performed with infiltration from 2005 to 2008. Pre-operative and 12-month radiographs were examined and HO graded according to the Brooker classification. Peri-operative analgesic requirements and NSAID use were noted and outcome was measured at 1 year with the Oxford Hip Score. RESULTS: Univariate and multivariate analysis indicated that single-dose periarticular NSAID infiltration did not reduce the incidence or grade of HO. Preoperative HO (p = 0.005) and enthesopathy (p = 0.027) were significant predictors of post-operative HO. The use of post-operative oral NSAID (except aspirin) significantly reduced HO (p = 0.001). Periarticular infiltration significantly reduced opiate analgesia use in the first 24 h (p < 0.001) and length of inpatient stay (p < 0.001). There was no difference in Oxford Hip Score at 1 year. CONCLUSION: Preoperative enthesopathies are a risk factor for postoperative HO. Periarticular infiltration of NSAID and local anaesthetic does not reduce HO incidence or grade in THR, but does reduce perioperative opiate requirements and length of hospital stay.

Developing a quantitative measurement system for assessing heterotopic ossification and monitoring the bioelectric metrics from electrically induced osseointegration in the residual limb of service members.

Poor prosthetic fit is often the result of heterotopic ossification (HO), a frequent problem following blast injuries for returning service members. Osseointegration technology offers an advantage for individuals with significant HO and poor socket tolerance by using direct skeletal attachment of a prosthesis to the distal residual limb, but remains limited due to prolonged post-operative rehabilitation regimens. Therefore, electrical stimulation has been proposed as a catalyst for expediting skeletal attachment and the bioelectric effects of HO were evaluated using finite element analysis in 11 servicemen with transfemoral amputations. Retrospective computed tomography (CT) scans provided accurate reconstructions, and volume conductor models demonstrated the variability in residual limb anatomy and necessity for patient-specific modeling to characterize electrical field variance if patients were to undergo a theoretical osseointegration of a prosthesis. In this investigation, the volume of HO was statistically significant when selecting the optimal potential difference for enhanced skeletal fixation, since higher HO volumes required increased voltages at the periprosthetic bone (p = 0.024, r = 0.670). Results from Spearman's rho correlations also indicated that the age of the subject and volume of HO were statistically significant and inversely proportional, in which younger service members had a higher frequency of HO (p = 0.041, r = -0.622). This study demonstrates that the volume of HO and age may affect the voltage threshold necessary to improve current osseointegration procedures.

Persistent synchondrosis of a primary sacral ossification center in an adult with low back pain.

BACKGROUND CONTEXT: Persistence of a primary sacral ossification center resulting in synchondrosis in adulthood is rare and can confound diagnostic decision making during patient management. PURPOSE: To present a synchondrosis between the sacral ala and sacral body in a healthy 23-year-old US Marine who had low back pain. STUDY DESIGN/SETTING: Case report. OUTCOME MEASURES: Self-report measures included a numerical pain scale and Roland Morris Disability questionnaire; physiological measures included plain film radiography, computed tomography scans, magnetic resonance imaging, and physical examination procedures; and functional measures included the patient's ability to run and sit without pain and to maintain US Marine Corps fitness standards. METHODS: The initial management of his low back pain included a course of nonsteroidal anti-inflammatory medication, chiropractic manipulation of the sacroiliac joints and adjacent tissues, and therapeutic exercise. When the patient's condition did not improve as quickly as anticipated, plain X-ray films were ordered; this revealed a vertical cleft in the sacrum at the site of the patient's pain. Further imaging showed the anomalous cleft to be a synchondrosis between the costal element and the centrum of the sacrum. Manual manipulation, physical training, and ergonomic advice were continued. RESULTS: Pain severity decreased from 7 to 0, and the Roland Morris score decreased from 14 to 1. He could sit for prolonged periods of time and exercise to Marine Corps standards. CONCLUSIONS: It is unlikely that the synchondrosis was the structure responsible for generating the patient's low back pain. However, such an anomaly is clinically relevant because it may mimic a fracture.

Acitretin-induced enthesitis in a patient with psoriatic arthritis.

A patient with psoriatic arthritis and cutaneous psoriasis took acitretin for 10 years to treat his skin lesions. Radiographs disclosed exuberant ossifications in several entheses. Their features were not typical for psoriatic arthritis but were consistent with acitretin-induced hyperostosis. Retinoids are known to induce hyperostosis, most notably when they are used in high dosages and over long periods. The concomitant presence of two conditions affecting the entheses may explain the exuberant nature of the ossifications in our patient.

Acquired heterotopic ossification in the settings of cerebral anoxia and alternative therapy: two cases.

Acquired Heterotopic Ossification (HO) has been well described in the literature as a recognized complication following spinal cord injury, traumatic brain injury and joint arthroplasty. Commonly, large proximal limb joints are affected. The underlying mechanisms for ectopic bone formation remain poorly elucidated. Post-stroke hemiplegia as a cause of neurogenic HO is rare, and no published reports of HO occurring after anoxic brain injury in adults have been documented. This study reports two unusual cases of acquired HO: (1) Polyarticular HO involving the ankle joint in a 24-year-old Chinese female who suffered severe anoxic encephalopathy following near drowning which resulted in persistent vegetative state; and (2) Elbow HO in chronic post-stroke hemiplegia occurring as a complication of alternative therapy following repeated forceful manipulation by a traditional practitioner in a 46 year-old male.

[Fracture analysis of a ceramic liner. Is in hip endoprosthesis replacement of ceramic on ceramic components with only one of the corresponding partners justified?]. / Bruchanalyse eines Keramik-Inlays. Ist bei einem Hüftendoprothesenwechsel mit der Gleitpaarung Keramik-Keramik der Wechsel nur eines korrespondierenden Partners sinnvoll?

The good biomechanical and tribological properties, together with the excellent biocompatibility, of ceramic-on-ceramic components, make them a preferential choice for total hip replacement surgery, at least in Europe. We report on a man admitted as an outpatient with painless grating in the hip one year after replacement of a ceramic femoral head, but not of the ceramic inlay. Clinical and radiological findings were indicative of a broken liner. This was confirmed during revision surgery, during which it was replaced by a polyethylene inlay; although the ceramic head appeared intact, it was replaced by a metal head. Inspection of the surface of the broken liner in the scanning electron microscope (SEM) revealed signs of material failure. We recommend careful inspection of ceramic-on-ceramic articulating components during total hip revision surgery and if there is any uncertainty, replacement of both so as to avoid premature failure.

Fractured heterotopic bone in myositis ossificans traumatica.

OBJECTIVE: To discuss the case of a patient with an acute fracture occurring through preexisting, quiescent, posttraumatic heterotopic bone formation of the gastrocnemius muscle. The lesion demonstrated a previously unreported pattern of healing. This case serves to demonstrate an infrequent event with a rare and heretofore unreported sequella. CLINICAL FEATURES: A 54-year-old man with preexisting, mature heterotopic bone within the left gastrocnemius muscle experienced reinjury to the site. The preexisting heterotopic bone was a result of a sporting injury that had occurred 32 years previously. At the time of the new injury, the patient experienced immediate, severe pain. Radiographs demonstrated a nondisplaced oblique fracture through the preexisting heterotopic bone. INTERVENTION AND OUTCOME: The patient was treated with protective wrapping and physiotherapy modalities. Because only the heterotopic bone was involved, the leg was not placed in a cast. Follow-up radiographs obtained 14 weeks later showed callus formation about the fractured site and evidence of union. CONCLUSION: Fractures occurring through mature heterotopic bone formations, such as those seen in myositis ossificans traumatica, are infrequent; callus formation with union of the fractured fragments is an even rarer occurrence.

Radiographic and morphologic studies of multiple miliary osteomas of cadaver skin.

OBJECTIVES: The purpose of this study was to examine the frequency, chemical composition, and radiographic and morphologic features of multiple miliary osteomas of the facial skin. STUDY DESIGN: Facial skin was obtained from 33 cadavers. After contact radiographs were taken, osteomas were examined by photo and scanning electron microscopy. Radiographic microanalysis of inorganic elements of the osteomas was also performed. In addition, clinical dental radiographic examinations were performed on 158 living subjects. RESULTS: Radiographic examination revealed milia-like osteomas in the facial skin of all of the cadavers. Nodules of 0.5 to 2.0 mm in diameter were scattered symmetrically in the skin of the cheek, mandibular angle, and forehead. Each nodule consisted of a concentric, multilamellated, osteoid cortex and an adipose medulla. Microanalysis suggested the presence of hydroxyapatite similar in composition to that of normal cortical bone. The condition was detected in 28% (44/158) of the living subjects by clinical dental radiographic examination. CONCLUSION: Multiple miliary osteoma is a very common condition and may not be related to specific diseases.

Accuracy of high-resolution computed tomography in cochlear implantation.

Multichannel cochlear implants are a proven method for the auditory rehabilitation of individuals who have severe-to-profound sensorineural hearing loss. These devices typically require insertion into the scala tympani of the cochlea to provide auditory stimulations. A patent scala provides the best chance for an adequate insertion of the electrode array. Preoperative high-resolution computed tomography imaging has traditionally been used to determine the patency of the scala tympani. Its ability to accurately predict the patency of the cochlea has been questioned in several retrospective studies. A prospective study was undertaken in 28 consecutive individuals undergoing cochlear implant surgery to compare the findings on high-resolution computed tomography with the surgical findings in an attempt to determine high-resolution computed tomography's accuracy. Cochlear obstruction caused by ossification was accurately predicted in six of six individuals but overestimated in the round window region in three individuals. High-resolution computed tomography accurately predicted patent cochleas in 19 individuals. No false-negative results were encountered. In this study sensitivity of high-resolution computed tomography was 100%, and specificity was 86%. High-resolution computed tomography appears to be more helpful than previously reported for determining cochlear patency.

[Special radiology of the hand in renal osteopathy]. / Spezielle Radiologie der Hand bei renaler Osteopathie.

The different radiographical abnormalities of the hand with renal osteodystrophy are demonstrated. The soft tissue immersion low-energy X-ray technique allows early detection of macrostructural changes of spongy and compact bone, irregularities of the cortex, defects and pseudocysts, osteosclerosis as well as calcifications in the soft tissue and arterio sclerosis of patients with chronic renal failure. Possible erroneous interpretations will be discussed.

Ossification of the posterior longitudinal ligaments: a cause of spinal stenosis syndrome.

Spinal Stenosis Syndrome (SSS) causes varying radiculopathies and myelopathies by compressing the spinal cord, rootlets and nerves within the bony canal. An enlarged and ossified posterior longitudinal ligament, a rare cause of the syndrome, can occupy up to 80% of the cervical spinal canal resulting in severe, sometimes permanent myelopathy. The clinical and the radiographic findings are discussed.