Reactive Bone Changes Research Articles

Enhanced antibiofilm potential of low-intensity pulsed ultrasound combined with 0.35% povidone-iodine in a rat model of periprosthetic joint infection.

Although low-intensity pulsed ultrasound (LIPUS) combined with disinfectants has been shown to effectively eliminate portions of biofilm in vitro, its efficacy in vivo remains uncertain. Our objective was to assess the antibiofilm potential and safety of LIPUS combined with 0.35% povidone-iodine (PI) in a rat debridement, antibiotics, and implant retention (DAIR) model of periprosthetic joint infection (PJI). A total of 56 male Sprague-Dawley rats were established in acute PJI models by intra-articular injection of bacteria. The rats were divided into four groups: a Control group, a 0.35% PI group, a LIPUS and saline group, and a LIPUS and 0.35% PI group. All rats underwent DAIR, except for Control, which underwent a sham procedure. General status, serum biochemical markers, weightbearing analysis, radiographs, micro-CT analysis, scanning electron microscopy of the prostheses, microbiological analysis, macroscope, and histopathology evaluation were performed 14 days after DAIR. The group with LIPUS and 0.35% PI exhibited decreased levels of serum biochemical markers, improved weightbearing scores, reduced reactive bone changes, absence of viable bacteria, and decreased inflammation compared to the Control group. Despite the greater antibiofilm activity observed in the PI group compared to the LIPUS and saline group, none of the monotherapies were successful in preventing reactive bone changes or eliminating the infection. In the rat model of PJI treated with DAIR, LIPUS combined with 0.35% PI demonstrated stronger antibiofilm potential than monotherapy, without impairing any local soft-tissue.

The Efficacy and Safety of an Intra-articular Dual-Acting Antibacterial Agent (TNP-2092) for Implant Infection-Associated Methicillin-Resistant Staphylococcus aureus.

Owing to the presence of microbial biofilm on the implant, the eradication of biofilm-associated infections poses a challenge for antibiotic therapies. The study aimed to investigate the efficacy and safety of the novel antibiotic agent TNP-2092 in the context of implant infections. In vivo, rats with periprosthetic joint infection (PJI) treated with antibiotics showed an increase in body weight and decrease in swelling, temperature, and width of knee, compared with the control group. Meanwhile, inflammatory markers in synovium and serum were decreased in the TNP-2092 group, consistent with the pathological results. Moreover, TNP-2092 was effective in eliminating bacteria and disruption biofilm formation, and further alleviated the abnormal bone absorption and reactive bone changes around the prosthesis. In conclusion, intra-articular injection of TNP-2092 is safe and effective in treating knee PJI in a rat model. The study provides a foundation for the future utilization of TNP-2092 in the management of implant-related infections.

S1796 Pancreatitis, Panniculitis and Polyarthralgia Syndrome: A Rare Complication of Pancreatic Pathology

Introduction: Pancreatitis, panniculitis, and polyarthritis (PPP) syndrome is a rare syndrome consisting of multiorgan extra-pancreatic manifestations of pancreatitis due to high serum lipase levels. Patients can often have little to no abdominal symptoms. The syndrome can also mimic infectious etiologies leading to misdiagnosis, mistreatment, and the possibility of deterioration. Case Description/Methods: A 64-year-old male with a history of alcohol abuse presented with painful nodular purulent lesions in his legs and bilateral joint pain in his hips and shoulders. NSAIDs and glucocorticoids did not provide relief. He was initially diagnosed with erythema nodosum. The patient had an elevated Erythrocyte Sedimentation Rate of 75 mm/h, C-reactive protein of 5.7 mg/dL, slightly elevated transaminases, and elevated Lipase of 2328 U/L. A basic metabolic profile and complete blood count were unremarkable. A computed tomography scan of the abdomen showed acute pancreatitis with peripancreatic inflammatory changes. It also showed partial occlusion thrombosis of the portal and superior mesenteric veins. Notably, the patient did not have any abdominal pain on presentation. MRI of the left calcaneus showed bone edema suggesting radiographic evidence of osteomyelitis. The patient was treated with a prolonged course of broad-spectrum antibiotics without improvement. A biopsy of the panniculitis lesions showed lobular panniculitis and ghost cells which were pathognomonic for pancreatic panniculitis. (Figure) Hence, the cause of panniculitis and bone necrosis was thought to be due to the intravascular leakage of lipase due to PPP syndrome. The patient’s polyarthralgia was described due to the deposition of free fatty acids in joints following fat autodigestion. Discussion: After the diagnosis of PPP syndrome, the patient was largely asymptomatic. This case highlights the importance of bone biopsy in diagnosing osteomyelitis. Reactive changes in bone on imaging could be seen in other non-infectious pathologies such as PPP syndrome, as highlighted in this case. The delayed diagnosis led to poor antibiotic stewardship and delay in treatment. This case also demonstrates the importance of a multidisciplinary team in identifying and managing a rare disease.Figure 1.: a. H&E stain of panniculitis lesion biopsy showing ghost cell (arrow) with a background of inflammation suggesting pancreatic panniculitis b. Partial thrombosis of portal vein (arrow) on CT of abdomen (coronal view) c. Partial thrombosis of superior mesenteric vein (arrow) in transverse view of CT abdomen d. Reactive bone changes on MRI of left foot (arrows).

Clinical and radiological outcome of arthroscopic Bankart repair in traumatic anterior glenohumeral instability with all-suture anchors

Background: Arthroscopic Bankart repair has evolved as an excellent treatment option in the management of recurrent shoulder instability as includes minimally invasive approach and significant reduction in perioperative morbidity. Anchor-related complications such as secondary cartilage damage and proud implant position are well described in literature. An all-suture anchor was developed and approved by the Food and Drug Administration in 2010. These anchors are placed into 1.4 mm diameter drilled holes which are smaller than the drill holes used for previously available anchor therefore minimize invasiveness and avoid complication related to metallic and bioabsorbable anchors. Aims and Objectives: This study to assess early radiological and clinical outcome after labral repair using all-suture anchors with specific consideration for bony reactions at the anchor site on magnetic resonance imaging. Materials and Methods: Twenty patients underwent labral repair using all-suture anchors were followed up for minimum of 1 year. Functional outcome was assessed on the basis of Rowe score, Constant and Murley score, and the American Shoulder and Elbow Surgeons score. The radiological appearance of bony reaction around the anchor site was judged by the presence of bony edema, tunnel widening (>3 mm), and cyst formation. Results: A total number of 56 all-suture anchors were implanted in 10 patients. The total Rowe score significantly improved from a mean of 24.4 preoperatively to 92.5 postoperatively. The American Shoulder and Elbow Surgeons score improved from a mean of 47.1 preoperatively to 88.6 postoperatively and the Constant and Murley score improved from a mean of 57.3 preoperatively to 90.6 postoperatively. On post-operative MRI out of 56 anchors implanted, 35 anchors did not display any reactive bone changes around anchor site. In 17 anchors, bone edema around a suture anchor was seen. Tunnel widening >3 mm was seen in four anchors. None of the anchors showed cyst formation around anchor site. Conclusion: Clinicoradiological outcome after arthroscopic shoulder instability using all-suture anchors was excellent at 1 year follow-up and radiological imaging revealed a good labral healing.

Predilection for developing a hematogenous orthopaedic implant-associated infection in older versus younger mice

BackgroundThe pathogenesis of hematogenous orthopaedic implant-associated infections (HOIAI) remains largely unknown, with little understanding of the influence of the physis on bacterial seeding. Since the growth velocity in the physis of long bones decreases during aging, we sought to evaluate the role of the physis on influencing the development of Staphylococcus aureus HOIAI in a mouse model comparing younger versus older mice.MethodsIn a mouse model of HOIAI, a sterile Kirschner wire was inserted retrograde into the distal femur of younger (5–8-week-old) and older (14–21-week-old) mice. After a 3-week convalescent period, a bioluminescent Staphylococcus aureus strain was inoculated intravenously. Bacterial dissemination to operative and non-operative legs was monitored longitudinally in vivo for 4 weeks, followed by ex vivo bacterial enumeration and X-ray analysis.ResultsIn vivo bioluminescence imaging and ex vivo CFU enumeration of the bone/joint tissue demonstrated that older mice had a strong predilection for developing a hematogenous infection in the operative legs but not the non-operative legs. In contrast, this predilection was less apparent in younger mice as the infection occurred at a similar rate in both the operative and non-operative legs. X-ray imaging revealed that the operative legs of younger mice had decreased femoral length, likely due to the surgical and/or infectious insult to the more active physis, which was not observed in older mice. Both age groups demonstrated substantial reactive bone changes in the operative leg due to infection.ConclusionsThe presence of an implant was an important determinant for developing a hematogenous orthopaedic infection in older but not younger mice, whereas younger mice had a similar predilection for developing periarticular infection whether or not an implant was present. On a clinical scale, diagnosing HOIAI may be difficult particularly in at-risk patients with limited examination or other data points. Understanding the influence of age on developing HOIAI may guide clinical surveillance and decision-making in at-risk patients.

Mouse model of Gram-negative prosthetic joint infection reveals therapeutic targets.

Bacterial biofilm infections of implantable medical devices decrease the effectiveness of antibiotics, creating difficult-to-treat chronic infections. Prosthetic joint infections (PJI) are particularly problematic because they require prolonged antibiotic courses and reoperations to remove and replace the infected prostheses. Current models to study PJI focus on Gram-positive bacteria, but Gram-negative PJI (GN-PJI) are increasingly common and are often more difficult to treat, with worse clinical outcomes. Herein, we sought to develop a mouse model of GN-PJI to investigate the pathogenesis of these infections and identify potential therapeutic targets. An orthopedic-grade titanium implant was surgically placed in the femurs of mice, followed by infection of the knee joint with Pseudomonas aeruginosa or Escherichia coli. We found that in vitro biofilm-producing activity was associated with the development of an in vivo orthopedic implant infection characterized by bacterial infection of the bone/joint tissue, biofilm formation on the implants, reactive bone changes, and inflammatory immune cell infiltrates. In addition, a bispecific antibody targeting P. aeruginosa virulence factors (PcrV and Psl exopolysaccharide) reduced the bacterial burden in vivo. Taken together, our findings provide a preclinical model of GN-PJI and suggest the therapeutic potential of targeting biofilm-associated antigens.

A young female presenting with unilateral sacroiliitis following dengue virus infection: a case report

BackgroundDengue is a common arthropod-borne viral infection in Sri Lanka which is spread by the mosquitos of the genus Aedes. The clinical features of dengue include high-grade fever associated with arthralgia and myalgia. However, dengue virus is not considered an arthritogenic virus. We report a case of a previously healthy young female who presented with imaging-confirmed right-sided sacroiliitis 10 days after developing dengue fever. This is the first reported case that shows a possible link between dengue infection and development of arthritis.Case presentationA 14-year-old Sri Lankan female presented to our medical unit with right buttock and hip pain of 3 weeks’ duration. She had serologically confirmed dengue infection 10 days prior to the onset of buttock pain. A clinical examination revealed features of right sacroiliitis. An X-ray of her sacroiliac joint showed joint space widening and reactive bone changes. Magnetic resonance imaging of her pelvis and sacroiliac joint confirmed the diagnosis of acute sacroiliitis. She had an erythrocyte sedimentation rate of 110 mm first hour with a normal C-reactive protein. Her human leukocyte antigen-B27, rheumatoid factor, antinuclear antibody, chikungunya antibody, hepatitis serology, Brucella serology, and tuberculin skin test were negative. She was treated with nonsteroidal anti-inflammatory drugs and showed gradual improvement.ConclusionsAfter excluding possible causes for sacroiliitis, we postulated that sacroiliitis in the index case could have been caused or triggered by dengue virus infection. However there is a possibility that the sacroiliitis merely coincided with the dengue virus infection. This case illustrates the possibility that dengue virus could have a link with the development of arthritis in the same manner as other arthritogenic viruses; possible mechanisms for this include direct invasion of the synovium and the joint tissue by the virus, immune complex formation and deposition in the joint tissue, and immune dysregulation. Further studies are needed in this field to gain more knowledge, as dengue infection is highly prevalent in Sri Lanka.

Oral-Only Linezolid-Rifampin Is Highly Effective Compared with Other Antibiotics for Periprosthetic Joint Infection: Study of a Mouse Model.

Background:The medical treatment of periprosthetic joint infection (PJI) involves prolonged systemic antibiotic courses, often with suboptimal clinical outcomes including increased morbidity and health-care costs. Oral and intravenous monotherapies and combination antibiotic regimens were evaluated in a mouse model of methicillin-resistant Staphylococcus aureus (MRSA) PJI.Methods:Oral linezolid with or without oral rifampin, intravenous vancomycin with oral rifampin, intravenous daptomycin or ceftaroline with or without oral rifampin, oral doxycycline, or sham treatment were administered at human-exposure doses for 6 weeks in a mouse model of PJI. Bacterial burden was assessed by in vivo bioluminescent imaging and ex vivo counting of colony-forming units (CFUs), and reactive bone changes were evaluated with radiographs and micro-computed tomography (μCT) imaging.Results:Oral-only linezolid-rifampin and all intravenous antibiotic-rifampin combinations resulted in no recoverable bacteria and minimized reactive bone changes. Although oral linezolid was the most effective monotherapy, all oral and intravenous antibiotic monotherapies failed to clear infection or prevent reactive bone changes.Conclusions:Combination antibiotic-rifampin regimens, including oral-only linezolid-rifampin and the newer ceftaroline-rifampin combinations, were highly effective and more efficacious than monotherapies when used against a preclinical MRSA PJI.Clinical Relevance:This study provides important preclinical evidence to better optimize future antibiotic therapy against PJIs. In particular, the oral-only linezolid-rifampin option might reduce venous access complications and health-care costs.

Giant cell tumor of the temporal bone presenting as a preauricular bulging mass

Giant cell tumor (GCT) of bone is an uncommon primary neoplasm that rarely occurs in the skull. The sphenoid and temporal bones are common sites in the skull for these tumors. GCTs of the temporal bone usually grow with medial extension and induce reactive bone changes. In this article, we describe a case of GCT presenting as a bulging preauricular mass with aggressive bone destruction.

A Study of Biochemical Profile in Cases of Osteo-Arthritis

Introduction: Osteo-arthritis is the most frequent cause of musculoskeletal disability. It is a common disorder of synovial joints characterised by destruction of hyaline articular cartilage, and reactive bone changes. Aim: To show the relation between Osteo-arthritis and metabolic syndrome. Materials and Methods: The components of metabolic syndrome like waist circumference, blood pressure, total triglycerides, HDL cholesterol and fasting glucose were measured. Results: HDL cholesterol levels between controls and cases were found to be highly significant. Conclusion: The present study shows that there is increased association of adversely changed components of metabolic syndrome with osteo-arthritis. Key words: Osteo-arthritis, metabolic syndrome, lipid profile, HDL, triglycerides.

Trudności diagnostyczne wynikające ze zmienności obrazów morfologicznych spondylodiscitis w obrazowaniu MR

Spinal infection (discitis; spondylodiscitis) presents a wide spectrum of pathologies. The method of choice for spondylodiscitis imaging is magnetic resonance (MR). It provides detailed anatomical information, especially concerning epidural space and spinal cord. The main aim of this article is the description and evaluation of spondylodiscitis morphological variation visible in magnetic resonance imaging. In this article we retrospectively analysed the patients diagnosed at the Department of Radiology of the Provincial Hospital No 2 in Rzeszów between October 2009 and October 2011. The subjects involved a group of five women aged 41-74 (mean 56.3 years) and eight men aged 46-69 (mean 61,3 years). All patients had spondylodiscitis symptoms. All patients underwent MRI examination before and after the contrast enhancement. In three patients additional CT examination was performed. Following the MRI procedure all patients were diagnosed with typical symptoms of spondylodiscitis. It also revealed a number of pathologies resulting from morphological spondylodiscitis variation. Other pathologies found on the MR images of the study group patients involved epidural intra-canal spinal pathological masses causing spinal cord compression, lung abscess, pyothorax, paravertebral abscesses and epidural empyemas, abscess between adjacent vertebral bodies, abscesses beneath anterior longitudinal ligament, and iliopsoas muscle abscesses. In all cases a destruction of vertebral bodies with end plates loss restriction and cortical layer discontinuity was observed. Moreover, one person was diagnosed with pathological vertebral body fractures and liquefactive necrosis of the vertebral body. Spondylodiscitis manifests itself in a great number of morphological variations visible on the radiological images. Apart from ordinary features of vertebral bodies and discs, progressive spinal destruction is observed together with reactive bone changes and soft tissue infiltration. The latter leads to a number of complications e.g. abscesses or even fistulas and also to the formation of obstacles in radiological images. The knowledge of radiological images together with overall evaluation of clinical and laboratory features enables a proper diagnosis.

MRI manifestations of soft-tissue haemangiomas and accompanying reactive bone changes

Soft tissue haemangiomas are common benign vascular lesions that can be accompanied by reactive changes in the adjacent bone structure. This study aimed to discuss the MRI features of soft-tissue haemangiomas with an emphasis on changes in bone. The radiographic and MRI findings of 23 patients (9 males, 14 females; mean age 25 years; age range 2-46 years) with soft-tissue haemangiomas were analysed retrospectively. MR images were evaluated for location of the lesion, size, configuration, signal features, contrast patterns, proximity to adjacent bone and changes in the accompanying bone. Excisional biopsy was performed in 15 patients. Radiographs demonstrated phleboliths in 8 patients (34%) and reactive bone changes in 4 (19%). On MRI, T₁ weighted images showed that most of the lesions were isointense or isohyperintense, as compared with muscle tissue; however, on T₂ weighted images all lesions appeared as hyperintense. Following intravenous gadolinium-diethylene triamine pentaacetic acid (DTPA) administration, homogeneous enhancement was observed in 3 lesions and heterogeneous enhancement was seen in 19. No enhancement was observed in one patient. Bone atrophy adjacent to the lesion was observed in four patients. MRI is the most valuable means of diagnosing deep soft-tissue haemangiomas. Bone changes can accompany deeply situated haemangiomas; in four of our patients, we found atrophy of the bone adjacent to the lesion. To our knowledge, this is the first report in the literature regarding atrophy of the bone adjacent to a lesion.

Histopathological perspective on bone marrow oedema, reactive bone change and haemorrhage

This article presents a systematic review of the current biomedical literature surrounding the aetiopathogenesis and histopathological features of bone marrow oedema, reactive bone change and haemorrhage. Bone marrow oedema is generally demonstrated as a non-specific finding on magnetic resonance imaging in association with infections, tumours and avascular necrosis. When it occurs in isolation as a primary event not triggered by any obvious bony pathology in the clinical setting of debilitating joint pain, it constitutes the “bone marrow oedema syndrome”. Although the latter diagnosis is based on magnetic resonance (MR) imaging, showing the lesion as areas of signal hyperintensity within the marrow, recent radiology–histology correlational studies have shown variably interstitial marrow oedema, necrosis, fibrosis and trabecular bone abnormalities. In light of these facts, the use of the term bone marrow oedema syndrome in a radiological context might be considered questionable, but histopathological techniques are not sensitive in detecting increased extracellular fluid. Reactive bone changes may be focal or diffuse and usually amount to increased bone formation. Bone marrow haemorrhage, due to trauma, results in bone bruising, a condition in which the size of the bruise and associated osteochondral injury determines the outcome, although the natural history of these lesions is still being researched.

Delayed gadolinium enhanced MRI of cartilage (dGEMRIC) of the first carpometacarpal (1CMC) joint: a feasibility study

The first carpometacarpal (1CMC) joint, at the base of the thumb, is a common site for symptomatic and radiographic osteoarthritis (OA) among the elderly 1–4. OA in the 1CMC joint can be particularly debilitating because it is associated with a decrease in pincer grip strength and limits activities such as writing and handling small objects 4. Currently, the diagnosis and staging of 1CMC OA is based on physical signs and symptoms and radiographic evidence of reactive bone changes 5. A deeper appreciation of OA etiology and progression in the 1CMC joint is currently limited by a lack of markers sensitive to early intraarticular degenerative changes, particularly those that are radiographically occult, that can be used to quantitatively assess disease status and therapeutic efficacy. The dGEMRIC (delayed Gadolinium Enhanced MRI of Cartilage) technique has previously been used in the knee and hip as a non-invasive method to evaluate one aspect of cartilage biochemical status, that of the spatial distribution of cartilage glycosaminoglycan (GAG) concentration 6–10, but has never been applied to the thin cartilage in the hand. This study found dGEMRIC evaluation of the 1CMC joint is technically feasible and demonstrates differences between cartilage in asymptomatic and OA joints, potentially providing an objective measure of disease progression and a means for better understanding biochemical changes which might precede cartilage destruction.

MRI and CT findings of the giant cell tumors of the skull; five cases and a review of the literature

Purpose To investigate CT and MR findings of giant cell tumors (GCTs) of the skull, an unusual site for such tumors. Materials and methods CT and MR features of five histologically proven giant cell tumors of the skull were retrospectively reviewed. We also reviewed 22 cases in the literature that included MR or CT findings. Results Three of the tumors originated from the temporal bone with predominantly medial extension, and the other two were centered in the body of the sphenoid bone and featured symmetrical soft tissue extension. CT images with bone window settings showed reactive bone changes for all three tumors of the temporal bone, suggesting slow growth for example, an expanded intradiploic space, expansive remodelling and development of foci of pressure erosion. GCTs of the sphenoid bone showed purely osteolytic changes without remodelling. Although the MR signals and enhancement patterns varied, all the tumors of the temporal bone had a markedly low intensity area on T2-weighted images, which was not seen in the tumors of the sphenoid bone. The findings for our cases generally corresponded to those reported in the literature. Conclusion Giant cell tumors of the skull have two preferential sites and may have characteristic tendencies as to their extent. Bone changes and MR signals appear to show differences between the two sites.

The diagnostic accuracy of MR imaging in osteoid osteoma

To analyse the MR imaging appearances of a large series of osteoid osteomas, to assess the ability of MR imaging to detect the tumour, and to identify potential reasons for misdiagnosis. The MR imaging findings of 43 patients with osteoid osteoma were reviewed retrospectively and then compared with other imaging modalities to assess the accuracy of MR localisation and interpretation. The potential for a missed diagnosis was 35% based solely on the MR investigations. This included six tumours which were not seen and nine which were poorly visualised. The major determinants of the diagnostic accuracy of MR imaging were the MR technique, skeletal location, and preliminary radiographic appearances. There was a wide spectrum of MR signal appearances of the lesion. The tumour was identified in 65% of sequences performed in the axial plane. The nidus was present in only one slice of the optimal sequence in 27 patients. Reactive bone changes were present in 33 and soft tissue changes in 37 patients. Reliance on MR imaging alone may lead to misdiagnosis. As the osteoid osteoma may be difficult to identify and the MR features easily misinterpreted, optimisation of MR technique is crucial in reducing the risk of missing the diagnosis. Unexplained areas of bone marrow oedema in particular require further imaging (scintigraphy and CT) to exclude an osteoid osteoma.

Bioscrew fixation of patellar tendon autografts

Biodegradable interference screw fixation was studied using patellar tendon autografts in a randomized, prospective multicenter comparison of the PLLA Bioscrew and a metal interference screw. sixty-eight of 114 (60%) patients (34 Bioscrew and 34 metal screw) enrolled were available for follow up an average of 35 months after surgery (range 24–65). There were 42 males and 26 females with an average age of 29 years (16–50). Tourniquet times and associated surgical findings were similar for the two groups. Postoperative KT, Tegner, and Lysholm scores were not statistically different between the two groups. Average follow up KT maximum manual side-to-side difference was 0.9 mm for Bioscrews and 1.4 mm for metal screws. Postoperative Lachman and pivot shift testing were equivalent for the two groups. Other than six of the 7 mm Bioscrews breaking during insertion in the femoral tunnel, there were no problems related to the PLLA implants. No statistical difference was found between the Bioscrew and the metal screw groups, and there were no osteolytic or other reactive bone changes observed associated with the PLLA Bioscrew. These data indicate that the PLLA Bioscrew functions reliably as an interference fixation screw for patellar tendon autografts.

Regional bone changes in deep soft tissue hemangiomas: radiographic and MR features.

To evaluate changes in bone adjacent to deep soft tissue hemangiomas of the extremities. We retrospectively reviewed the plain films of 115 patients with histologically proven deep soft tissue hemangiomas of the extremities. The length and pattern of the bone changes were analyzed and correlated with the MRI examination (n = 55) and surgical findings. Plain film studies demonstrated reactive bone changes adjacent to the deep soft tissue hemangiomas in 24 (21%) patients and phleboliths in 23 (20%) patients. The results of plain film analysis revealed a wide spectrum of regional bone changes adjacent to the hemangiomas, including periosteal reactions (16%), regional osteopenia (1%), cortical erosion (3%), bony overgrowth (3%), coarsening of the trabeculae (5%), and a combination of the above changes (4%). The length of the reactive changes corresponded approximately to the size of the hemangioma in 70% and was longer than the largest dimension of the hemangioma in 30%. Of the 55 patients studied with MRI, 39 (71%) patients had normal bones and 16 (29%) had bone changes. Deep soft tissue hemangiomas may cause changes in adjacent bones. Familiarity with the pattern of reactive bone changes may help to avoid misdiagnosis.

Percutaneous therapy of osteoid osteoma

Osteoid osteomas are tumors with intense clinical symptoms and extensive reactive bone changes far exceeding the volume of the lesion itself. Because of their small size they can be approached by minimally invasive surgical procedures. We treated ten symptomatic patients with osteoid osteomas (n 6 hip point, n 1 iliac bone, n 1 femoral diaphysis, n 2 tibial diaphysis) by excision of the nidus with a 3-mm Harlow-Wood needle using a percutaneous CT-guided approach. Seven patients with residual tumor were treated with either thermocautery (n 2) or sclerosis with 1 ml of 96% ethanol (n 5). Six patients had instant and constant relief (3 years' observation) of their pain. In two patients a second transcutaneous intervention was successful. Only two patients needed open resection. Compared with the invasive open resection of the tumors, sometimes even putting the stability of the femoral neck at risk, transcutaneous CT-guided enucleation of the nidus of the osteoid osteoma with additional sclerotherapy is a good alternative method, especially in the region of the femoral neck.

Subacromial bursography. An anatomical and clinical study.

Impingement of the rotator cuff beneath the coracoacromial arch without associated rupture of the cuff or reactive bone changes on the undersurface of the acromion is a well established clinical diagnosis. The value of subacromial bursography in the assessment of this condition was investigated in an anatomical study of fifteen cadavera and a clinical study of thirty-one patients. The subacromial bursa is situated like a cap over the rotator cuff and can be demonstrated roentgenographically by the injection of contrast material in shoulders from cadavera and living subjects. This bursa is composed of subacromial and subdeltoid portions as well as a subcoracoid extension in some individuals. However, it is the anterior portion of the bursa, under the coracoacromial arch, that is most significant, since this overlies the deep structures involved in the impingement syndrome. The normal subacromial bursa easily accepts five to ten milliliters of contrast medium. However, if the bursal walls are thickened and edematous, the bursa will be difficult to demonstrate roentgenographically or it will accept only a few milliliters of contrast material. The findings in this study suggest that when the findings on the bursogram are normal, a diagnosis of chronic impingement by the coracoacromial arch should be questioned.