A rare case of juxtaarticular osteoid osteoma of the calcaneus initially misdiagnosed as juvenile chronic arthritis

Juxtaarticular osteoid osteoma is frequently misdiagnosed because the symptoms may mimic arthritis, and radiographs may not be characteristic. A rare case of subtalar pain lasting 5 years in a female teenager is presented here. The initial diagnosis was monarticular juvenile chronic arthritis. Family history was misleading because her mother had rheumatoid arthritis (RA).

Plantar calcaneal enthesophytes: new observations regarding sites of origin based on radiographic, MR imaging, anatomic, and paleopathologic analysis

OBJECTIVE

To determine the relationship between sites of calcaneal plantar enthesophytes and surrounding fascial and soft tissue structures using routine radiography, MR imaging, and data derived from cadaveric and paleopathologic specimens.

DESIGN AND PATIENTS

Two observers analyzed the MR imaging studies of 40 ankles in 38 patients (35 males, 3 females; mean age 48.3 years) with plantar calcaneal enthesophytes that were selected from all the ankle MR examinations performed during the past year. Data derived from these MR examinations were the following: the size of the enthesophyte; its location in relation to the plantar fascia (PF) and flexor muscles; and the thickness and signal of the PF. The corresponding radiographs of the ankles were evaluated at a different time by the same observers for the presence or absence of plantar enthesophytes and, when present, their measurements. A third observer reviewed all the discordant observations of MR imaging and radiographic examinations. Two observers analyzed 22 calcaneal specimens with plantar enthesophytes at an anthropology museum to determine the orientation of each plantar enthesophyte. MR imaging of a cadaveric foot with a plantar enthesophyte with subsequent sagittal sectioning was performed to provide further anatomic understanding.

RESULTS

With regard to MR imaging, the mean size of the plantar enthesophytes was 4.41 mm (SD 2.4). Twenty (50%) enthesophytes were located above the PF, 16 (40%) between the fascia and abductor digiti minimi, flexor digitorum brevis and abductor hallucis muscles, and only one (3%) was located within the PF. In three (8%) cases the location was not determined. The size of enthesophytes seen with MR imaging and radiographs was highly correlated (P<0.01). The interobserver agreement for all measurements was good (Pearson >0.8, kappa >0.9). Eleven of the 22 bone specimens had plantar enthesophytes oriented in the direction of the abductor digiti minimi and 11 oriented in the direction of the flexor digitorum brevis and PF. The cadaveric sections revealed different types of enthesophytes.

CONCLUSIONS

Plantar calcaneal enthesophytes arise in five different locations: at the insertion sites of abductor digiti minimi and flexor digitorum brevis muscles; between the PF and these muscles; and, less frequently, within the PF and at the insertion site of the short plantar ligament.

Orientation and distribution of collagen fibers in the sagittal plane of the human adult calcaneus

Human right calcaneus bone, consisting of hydroxyapatite and collagen fibers, was cut in the sagittal plane which was parallel to the long axes of the calcaneus bone and the human lower limb, into samples approximately 1.5 mm thick. The angular dependence of transmitted microwave intensity at 12 GHz was measured for each sample, using Osaki's microwave method. The direction and the degree of collagen-fiber orientation for the cut specimens changed with changing position from the heel end to the anterior, along to the long axis of the calcaneus bone. The direction of orientation deviated by about -60 degrees from the direction of the long axis of the human lower limb, in the region between the heel end and the middle, and by about 60 degrees near the anterior. The position at which the orientation angle changed drastically from negative to positive corresponded to the neck defined as the position where a posterior face of the talus contacts the calcaneus. The results suggest that the mechanical stress applied to the neck of the calcaneus bone from the lower limb may effectively disperse, on average, in two different directions where the collagen fibers are oriented at the neck.

Quantitative magnetic resonance imaging in the calcaneus and femur of women with varying degrees of osteopenia and vertebral deformity status

Quantitative magnetic resonance imaging (QMRI) allows measurement of two parameters that are related to the integrity of the trabecular bone: R2*, the rate constant of the free induction signal, and trabecular bone volume fraction (BVF), the counterpart of apparent density. In this work, R2* and BVF were measured in 68 women (mean age, 58.2 +/- 9.5 years) of varying spinal bone mineral density (BMD) T scores (mean, -1.37 +/- 1.54) and vertebral fracture status on a commercial 1.5 T whole-body imager using customized image acquisition and processing techniques. Twenty-five of the patients had vertebral fractures, characterized by the total cumulative deformity burden exceeding 200%. R2* was measured in the calcaneus and proximal femur and BVF could be measured in the calcaneus only. On a pixel-by-pixel basis, calcaneal R2* and BVF within each subject were highly positively correlated (r2 = 0.61 +/- 0.11) but the correlation of region-of-interest (ROI) means for different calcaneal sites among patients was weaker (r2 = 0.34; p < 0.0001). The strongest discriminator of vertebral deformity was R2* of the calcaneus, which was lower in the fracture group, consistent with lower trabecular density. Among the calcaneal sites examined, the subtalar region, a location characterized by dense nearly horizontal trabeculae that transmit the stresses imparted by body weight from the tibia to the heel, best discriminated the two groups (p = 0.0001), with 77% diagnostic accuracy as determined from the area under the receiver operating characteristic (ROC) curve (compared with 66% for vertebral BMD). The cavum calcanei, an anterior site of low trabecular density, and the tuber calcanei (the location ordinarily used for ultrasound measurements) also had significantly reduced R2* in the fracture group (p < 0.005 and p = 0.01, respectively). The R2av*, computed as the average of all pixels in the calcaneus, was a strong discriminator as well (p < 0.005). On the other hand, calcaneal BVF was only marginally discriminating (p = 0.05). Among the BMD sites examined, the lumbar spine (average L1-L4) was significant (p = 0.005, 66% diagnostic accuracy), as was the femoral neck (p = 0.01). The data suggest the calcaneus to be suited as a surrogate site to assess vertebral osteoporosis and that R2* is sensitive to alterations in bone quality not captured by density.

Fine-needle aspiration diagnosis of giant cell tumour of bone presenting at unusual sites

Giant cell tumour (GCT) of bone is a distinctive neoplasm, which has only recently been included within the diagnostic purview of the cytopathologist. Four cases of GCT of bone diagnosed primarily and exclusively by fine needle aspiration cytology (FNAC), presenting at unusual sites, are presented with a view to highlight the cytomorphologic features of this tumour and its differential diagnosis on FNAC. Each of these cases were distinctive by virtue of their localisation, but presented as classical expansile osteolytic lesions roentgenologically. Despite the paucity of literature regarding the cytodiagnosis of these lesions, the authors nevertheless recommend FNAC as a primary tool in the diagnosis of these lesions.

Intraosseous lipoma of the calcaneus: a review and report of four cases

Intraosseous lipomas have been reported as rare tumors in the lower extremity. They have been identified in the tibia, fibula, metatarsals, and calcaneus. They are frequently misdiagnosed as other tumors, especially unicameral bone cysts or aneutysmal bone cysts when found within the calcaneus. A detailed description of intraosseous calcaneal lipomas and their treatment is given. Surgical technique and four case reports are presented. One of the cases involved a pathologic calcaneal fracture, a finding to the authors' knowledge that has not been previously reported.

[Combined method of treating dislocated fractures of the calcaneus]

PURPOSE OF THE STUDY

The treatment of dislocated intraarticular fractures of calcaneus is still an unsolved chapter of traumatology. Our own poor long-term results of a purely conservative procedure has led us to develop a combined method of a direct and indirect reduction of calcaneus with the subsequent stabilization which we have been using since 1994. The basic principle of the method consists in the combination of a direct reduction of dislocated fragments of articular surfaces and indirect of calcaneus as a whole with the subsequent transfixation of calcaneus by K-wires.

MATERIAL

In the period of 1994-2001 we have treated in total 261 patients with 302 fractures of calcaneus, of which 218 were men (83.5%) and 43 women (16.5%) in the age range from 13 to 82 years (average age 45.1 years). By our own surgical method we treated 213 patients with 248 fractures, of which 180 were men (84.5%) and 33 women (15.5%) in the age range of 13-79 years (average age 44.8 years). Conservatively handled were 54 fracture in 48 patients. In the long-term followed up group we included 160 patients with 187 fractures operated on by identical method observing a minimum two-year interval after the operation. Of them 134 were men (83.8%) and 26 women (16.2%) in the age range of 15-75 years (average age 44.3 years). Of 248 operated on fractures of calcaneus 159 were joint-depression type (64.1%), 61 tongue type (24.6%) and 28 comminuted (11.3%) types of fractures. The time interval between the injury and operation ranged between 6 hours and 3 weeks (average 18.5 hours), however most patients we operated on on the day of injury.

METHODS

The basic principle of the method was a combination of a direct reduction of dislocated fragments of articular surfaces and indirect reduction of the calcaneus as a whole with a subsequent transfixation of the calcaneus by K-wires. After draping and setting of the image intensifier we proceeded to the actual surgery and divided the whole procedure of reduction and subsequent stabilization into 4 phases: Phase I--traction Phase II--elevation Phase III--compression Phase IV--transfixation In the first traction phase we inserted K-wire transversely through the distal-posterior edge of the calcaneus and connected it to the U-handle in order to achieve a proper effect of the traction. By traction distally along the long axis of the limb we restored the height and length of the calcaneus. Simultaneous pendular movements in eversion/inversion direction released the fragments and considerably facilitated the subsequent reduction. In the second, elevation phase the procedure differed according to individual types of fracture. In joint-depression type we inserted a blunt Steinmann pin or better a curved transpedicular elevator under the dislocated posterior articular surface through skin plantar stab incision and an ever-present primary transverse line of the fracture. In the tongue type of fracture we first introduced in the second phase a thick K-wire (3 mm) along the long axis of the tongue fragment and reduce the fragment by leverage elevation with a simultaneous continuous U-handle traction. After obtaining the desirable position we fixed the fragment by a K-wire vertically introduced from the upper part of calcaneal tuberosity (anteriorly and laterally from the origin of the Achilles tendon) towards the planta. If the medial part of the posterior articular surface remained dislocated we finished its reduction by means of elevator as in the preceding type of the fracture. The third and fourth phases of the surgical procedure was again identical for both types of fractures. In the third, compression phase we performed manually lateral compression of fragments under permanent traction. In the fourth, transfixation phase we first transfixed the reduced position of fragments formed by the primary longitudinal and transverse line. Under continuous radiograph checking in the lateral projection we inserted K-wires gradually from the lateral aspect, about 1.5 cm beneath the lateral malleolus into sustentacular fragment. Additional, mostly 2 K-wires we inserted under continuous traction and counter-traction along the long axis of the calcaneus and as the last step we drilled K-wires from the plantar side from calcaneal tuberosity into the fragments of the posterior articular surface.

RESULTS

In the group of long-term followed up patients we evaluated the Creighton-Nebraska Health Foundation score in 160 patients who were on average 43.4 months after operation. The obtained values of the score ranged between 63-100 points with the average of 83.9 points. In 27 patients the result was very good (16.9%), in 89 patients good (55.6%), in 24 patients fair (15.0%) and in 20 patients the result was poor (12.5%).

DISCUSSION

The first results of our method of 1998 have proved that it is necessary to combine the basic procedures of direct reduction of joint fragments, i.e. restoration of the calcaneus as a whole, namely in a strictly recommended sequence with a subsequent transfixation by K-wires. We do not use surgical procedures with open reduction and internal fixation (ORIF) differing mutually by the chosen surgical approach and the type of internal fixation used. As compared to ORIF our method has a significantly broader indication range. It can be used for the operation of patients regardless of the age, presence of associated diseases (diabetes, vascular affection) or local affection (a marked oedema, haematoma, non-infected skin blisters). The comparison of the general outcomes of the treatment in our group of patients, 72.5% of excellent and good results and only 12.5 of poor results, corresponds with the values of equally extensive foreign group of patients. In addition, as concerns the number of the incidence of deep infects in closed fractures (0.8%) the values in our group are in comparison several times lower and amputation of the limb was not necessary in any of the cases. It should be also noted that our group of patients has only a minimal indication limitation and operated on are also risk patients who never get in "filtered" groups treated by open method. Therefore it may be stated that the general results are in case of our method markedly better.

CONCLUSION

The proposed method requires neither a specialist nor any expensive technical equipment and as a result it may be used both at orthopaedic and surgical departments and due to its undemanding nature and short hospitalization it is also very acceptable from the economic viewpoint.

High-resolution magnetic resonance imaging to assess trabecular bone structure in patients after transplantation: a review

After organ transplantation patients have a higher incidence of osteoporotic fractures. Bone mineral density (BMD) measurements to assess fracture risk are of limited value in these patients. On the other hand, structure-based techniques have shown promise. In this review, the use of high-resolution magnetic resonance imaging in the analysis of the trabecular bone structure in patients before and after renal and cardiac transplantation cross-sectionally is presented. The analyses of calcaneal trabecular structure were compared with BMD with regard to the prediction of therapy-induced bone loss and osteoporotic fracture status. Sagittal and axial T1-weighted spin-echo sequences with a voxel size of 0.2 x 0.2 x 1 mm were performed at 1.5 T and structure measures analogous to bone histomorphometry were calculated. In addition, fracture status of the spine and of the peripheral skeleton was assessed. Structure measures showed significant differences between healthy controls and patients before and after renal and cardiac transplantation (p < 0.01). Osteoporotic fractures were found in approximately 35% of the transplant patients; the percentage was higher in the cardiac transplants. Structure measures and BMD were lower in patients with fractures; differences were more significant in the cardiac transplant patients. Using receiver operating characteristic analyses the diagnostic performance in differentiating patients with and without fractures was highest when BMD and structure measures were combined. Structure measures performed better than BMD in the cardiac transplant patients, whereas results were comparable in the renal transplant patients. In conclusion, structure measures determined in high-resolution magnetic resonance images may be useful in assessing changes of trabecular bone after organ transplantation and may improve the prediction of fracture risk.

Heel spur formation and the subcalcaneal enthesis of the plantar fascia

OBJECTIVE

To describe the structure and significance of subcalcaneal heel spurs associated with the plantar fascia.

METHODS

The enthesis of the plantar fascia was removed from 17 elderly cadavers by sagittal saw cuts either side of the medial tuberosity, radiographs were taken, and the tissue was processed for routine histology. Sagittal sections were stained with toluidine blue, Masson's trichrome, or alcian blue, and sections were matched with the corresponding radiographs.

RESULTS

Spurs develop on the deep surface of the plantar fascia but their formation is heralded by degenerative changes that occur within it. According to differences between small and large spurs, we propose that there are 3 stages in their development: (1) an initial formation of cartilage cell clusters and fissures at the plantar fascia enthesis; (2) thickening of the subchondral bone plate at the enthesis as small spurs form; (3) development of vertically oriented trabeculae buttressing the proximal end of larger spurs. The spurs grow by a combination of intramembranous and chondroidal ossification.

CONCLUSION

Contrary to popular belief, subcalcaneal heel spurs cannot be traction spurs as they do not develop within the plantar fascia itself. They are thus fundamentally different from heel spurs in the Achilles tendon. We suggest instead that they develop as a consequence of degenerative changes that occur in the plantar fascia enthesis.

Bone marrow ill-defined hyperintensities with tarsal coalition: MR imaging findings

INTRODUCTION

To report the occurrence and pattern of ill-defined subchondral hyperintensities on Magnetic Resonance (MR) imaging in patients with talocalcaneal coalition (TCC).

METHODS AND MATERIAL

MR imaging of both feet was performed in 10 consecutive patients with 14 TCCs. There were eight males and two females with ages ranging from 9-52 years (mean 25 years). Twelve of the 14 TCCs were symptomatic. MR imaging sequences included T1- and T2-weighted as well as STIR images. The images were evaluated for the presence, extent and location of ill-defined subchondral hyperintensities on MR images in the hindfoot.

RESULTS

Ill-defined subchondral hyperintensities on MR imaging were present in 12 (86%) of the 14 hindfeet with TCCs. Two of these were without symptoms. No abnormalities were seen in two symptomatic hindfeet.

DISCUSSION AND CONCLUSION

In our series hyperintensities located in the subchondral bone adjacent to the coalition was relatively common in TCC. The presence of this specific pattern in the subchondral bone adjacent to the coalition may be indicative of tarsal coalition.

Calcaneal apophysitis: a quantitative radiographic evaluation of the secondary ossification center

BACKGROUND

Calcaneal apophysitis in children is a self-limited condition that may interfere with walking and physical performance in sports, thus causing concern to the patient and parents. There is still controversy about the significance of the radiographic changes in children with heel pain, since the report of Sever in 1912. One of the reasons is that normal children may display a considerable variation in the radiographic aspects of the secondary ossification center of the calcaneus at different ages.

METHODS

In this investigation, the developmental aspects of primary and secondary ossification centers of the calcaneus were studied in radiographs obtained from healthy boys and from boys with calcaneal apophysitis. The normal population comprised 392 children and adolescents ranging in age from 6 to 15 years. There were 69 individuals with calcaneal apophysitis ranging in age from 8 to 14 years. Lateral standard radiographs were obtained of both heels, and a copper step wedge was used as a calibration to determine bone density. The following parameters were analyzed on the plain films: time of appearance, fusion and number of fragments of the secondary nucleus, area and bone densitometry of the primary and secondary ossification centers of the calcaneus.

RESULTS

In the normal population, the ossification of the secondary nucleus began at 7 years of age, and at 15 years of age, the nucleus was fused in all individuals. In the apophysitis group, the secondary ossification center was present and not fused in all individuals. Both secondary nuclei increased in size with age with no difference between the two groups. Regarding bone density, both the primary and secondary nuclei were less dense in the apophysitis group than their counterparts in the normal population. The most significant difference between the two populations referred to the degree of fragmentation, which was greater in the apophysitis group.

CONCLUSION

Our data showed that the sclerotic aspect of the secondary nucleus of the calcaneus is a normal feature and, therefore, should not be used to establish the diagnosis of Sever's disease. The most consistent difference between the normal and apophysitis group was related to the more fragmented aspect of the secondary nucleus in the latter individuals, which may suggest a mechanical etiology for that condition.

Bone mineral density, calcaneal ultrasound, and bone turnover markers in women with ankylosing spondylitis

OBJECTIVE

To assess bone mineral density (BMD) by dual energy x-ray absorptiometry (DEXA) and calcaneal quantitative ultrasound (QUS) in a cohort of pre- and postmenopausal women with ankylosing spondylitis (AS), and to determine any relationships with markers of bone turnover and disease activity or severity.

METHODS

Fifty premenopausal and 16 postmenopausal women with AS were studied. Clinical and radiological status was assessed by the Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), Bath AS Metrology Index (BASMI), and Bath AS Radiology Index (BASRI). BMD of the hip and spine was measured by DEXA, and QUS measured at the heel. Serum osteocalcin (OC), bone-specific alkaline phosphatase (BALP), urinary D-pyridinoline crosslinks (D-PYR), and C-reactive protein (CRP) were assayed.

RESULTS

Women with AS (n = 66) had reduced BMD at the hip compared to age and sex matched controls (n = 132). The mean t scores were -1.1 and -2.0, and z scores -0.4 and -0.37, for pre- and postmenopausal women, respectively. Four (6%) had osteoporosis and 34 (52%) had osteopenia according to the WHO definitions. Using a multiple regression model, femoral neck BMD was found to be significantly affected by age, body mass index, and the sacroiliac radiographic score. There were no significant correlations of BMD with disease duration or disease activity. QUS measures did not correlate with DEXA measures of BMD. Women with AS had significantly lower markers of bone formation, OC and BALP, and a trend to higher D-PYR than controls. Serum OC levels correlated negatively with femoral neck BMD, whereas D-PYR correlated with CRP levels.

CONCLUSION

Women with AS have reduced hip BMD, 0.39 SD below age and sex matched controls. Bone turnover in women with AS is characterized by low OC and BALP.

The role of biomechanical factors and HLA-B27 in magnetic resonance imaging-determined bone changes in plantar fascia enthesopathy

OBJECTIVE

To study the role of biomechanical factors and HLA-B27 in plantar fasciitis.

METHODS

T1-weighted and T2 spectral presaturation with inversion recovery (fat suppressed) magnetic resonance imaging (MRI) sequences of the plantar fascia insertion and adjacent bone were performed on 28 patients with plantar fasciitis; 17 had spondylarthropathy (SpA)-associated disease, and 11 had mechanically induced disease. The relationship between the degree of bone edema, scored on a semiquantitative scale (from absent to severe), and the patient's HLA-B27 status was determined.

RESULTS

On MRI, edema within the soft tissue at the enthesis was evident in both groups. Bone edema in the adjacent calcaneum was evident in 64.7% (11 of 17) of patients with SpA and in 45% (5 of 11) of those with mechanically induced disease (P = 0.441). HLA-B27 was identified in 9 (53%) of the patients with SpA but in none (0%) of those with mechanically induced disease. All 6 of the SpA patients with extensive bone edema but none of the 5 SpA patients with mild bone edema were HLA-B27 positive (P = 0.002).

CONCLUSION

The association of HLA-B27 with bone pathology in early enthesitis may have implications for a better understanding of the pathogenesis of SpA.

Histological abnormalities of the calcaneum in congenital talipes equinovarus

Six calcaneal fragments from patients aged 2, 3, 4, and 5 years with relapsed talipes, and two normal feet from a 40-week-old stillborn fetus were studied. All tissue was sectioned in the sagittal or coronal plane and stained using alcian blue and sirius red to distinguish cartilage and bone. Immunocytochemistry was performed to illustrate collagen types I and II. Within the clubfoot calcaneum, there were fewer chondrocytes and a diminished number of cartilage canals. Although a growth plate was present, the zones of differentiated chondrocytes were not apparent and the chondrocytes were smaller and flatter. The alcian blue staining within the spherical physis was paler than normal, suggesting that the amount of extracellular proteoglycans was reduced. Overall, the growth plate region of the talipes calcaneum resembled that of a permanent cartilage, like articular cartilage. Abnormalities were also seen in the ossification center. Cartilage spicules were rare, and developing bone frequently abutted directly onto the growth plate cartilage. The relative absence of a primary spongiosa suggested that the physis was virtually inactive and endochondral bone formation was retarded. These findings are consistent with the hypothesis that an intrinsic primary growth disorder causes the formation of a small hypoplastic bone and, subsequently, a smaller foot.

Bone structure of the distal radius and the calcaneus vs BMD of the spine and proximal femur in the prediction of osteoporotic spine fractures

The aim of this study was to compare structure measures obtained from high-resolution MR images of the calcaneus and the distal radius with bone mineral density (BMD) of the spine and hip in the prediction of osteoporotic spine fracture status. High-resolution MR images of the calcaneus and radius were obtained in 24 post-menopausal women with spine fractures and 22 age-matched controls. Imaging was performed at 1.5 T using a T1-weighted spin-echo sequence (slice thickness 1 mm, in-plane spatial resolution 195 x 195 microm(2)). Structure analysis was performed using parameters analogous to standard histomorphometry. Bone mineral density of the spine was obtained using quantitative CT and of the hip with dual-energy X-ray absorptiometry. Significant differences between both patient groups were obtained with BMD and all structure parameters ( p<0.05). Using receiver operating characteristic analysis to determine the diagnostic performance in differentiating both groups, the best results were found for BMD of the spine, one of the radial structure measures and a combination of the calcaneal structure measures. In this study BMD of the spine and structure measures of the distal radius were best suited to predict the osteoporotic fracture status of the spine. A combination of BMD and structure measures did not yield any additional information on fracture status.

Bilateral calcaneal intraosseous lipoma: a case report

Intraosseous lipoma is a rare benign primary lesion of bone. Approximately 180 cases have been reported to date. In the literature, we have been able to find only three patients with bilateral calcaneal involvement. We present a 34-year-old woman who was diagnosed with intraosseous lipoma in both calcanei.

Changes in calcaneal trabecular bone structure assessed with high-resolution MR imaging in patients with kidney transplantation

The purpose of this study was to use high-resolution magnetic resonance (HR-MR) imaging to analyze the trabecular bone structure of the calcaneus in patients before and after renal transplantation and to compare this technique with bone mineral density (BMD) in predicting therapy-induced bone loss and osteoporotic fracture status. HR-MR imaging (voxel size: 0.195 x 0.195 x 1 mm) was performed at 1.5 T with an axial and sagittal orientation in 48 patients after transplantation, 12 patients before renal transplantation and 20 healthy controls. Structure measures analogous to standard histomorphometry and fractal dimension were determined in these images. BMD measurements of the lumbar spine and the proximal femur were obtained in the healthy female controls and the patients. Vertebral and peripheral fracture status were determined in all patients. The structural measures app.BV/TV, Tb.Sp, Tb.Th and Tb.N showed significant differences between controls and patients (p<0.05) while fractal dimension showed no significant differences. Neither the structural measures nor BMD showed significant differences between patients before and after transplantation. Correlations between time after transplantation versus structural measures and BMD were not significant. Differences between fracture and nonfracture patients were significant for the structural measures app.BV/TV, Tb.Sp and Tb.N (axial images) as well as for app.Tb.Th (sagittal images) and spine BMD (p<0.05) but not for hip BMD. Using odds ratios the strongest discriminators between patients with and without fractures were app. BV/TV, app.Tb.Sp (axial images) and app.Tb.Th (sagittal images), even after adjustment for age and BMD. Using receiver operating characteristic analysis the highest diagnostic performance was found for a combination of BMD and structural measures. In conclusion, our results indicate that structural measures obtained from HR-MR images may be used to characterize fracture incidence in kidney transplant patients; the best results, however, are obtained using a combination of BMD and structural measures.

Functional interactions between tumor and peripheral nerve: morphology, algogen identification, and behavioral characterization of a new murine model of cancer pain

This paper describes a model of tumor-induced bone destruction and hyperalgesia produced by implantation of fibrosarcoma cells into the mouse calcaneus bone. Histological examination indicates that tumor cells adhere to the bone edge as early as post-implantation day (PID) 3, but osteolysis does not begin until PID 6, correlating with the development of hyperalgesia. C3H/He mice exhibit a reproducible hyperalgesia to mechanical and cold stimuli between PID 6 and 16. These behaviors are present but significantly reduced with subcutaneous implantation that does not involve bone. Systemic administration of morphine (ED(50) 9.0 mg/kg) dose-dependently attenuated the mechanical hyperalgesia. In contrast, bone destruction and hypersensitivity were not evident in mice implanted with melanoma tumors or a paraffin mass of similar size. A novel microperfusion technique was used to identify elevated levels of the putative algogen endothelin (ET) in perfusates collected from the tumor sites of hyperalgesic mice between PID 7 and 12. Increased ET was evident in microperfusates from fibrosarcoma tumor-implanted mice but not from melanoma tumor-implanted mice, which are not hyperalgesic. Intraplantar injection of ET-1 in naive and, to a greater extent, fibrosarcoma tumor-bearing mice produced spontaneous pain behaviors, suggesting that ET-1 activates primary afferent fibers. Intraplantar but not systemic injection of the ET-A receptor antagonist BQ-123 partially blocked tumor-associated mechanical hyperalgesia, indicating that ET-1 contributes to tumor-induced nociception. This model provides a unique approach for quantifying the behavioral, biochemical, and electrophysiological consequences of tumor-nerve interactions.

Eleven cases of intraosseous lipoma of the calcaneus

Intraosseous lipomas are rare benign primary bone tumors, with an incidence of one per thousand bone tumors. We studied eleven cases of intraosseous lipoma of the calcaneus. All the patients received radiographic examinations and MRI with T1-and T2-weighted images with Gd-DTPA enhancement. Seven patients received tumor curettage. Plain radiographs demonstrated that all of the lesions showed clear osteolysis surrounded by a sclerotic margin in the central body of the calcaneus. MRI revealed that all the lesions had demarcated homogenous high signal intensity lesions on both T1- and T2-weighted images, which strongly suggested adipose tissue. In 5 cases, the center of the lesion showed low signal intensity lesions on T1-weighted images, suggesting the existence of central necrosis or cyst formation. After excising the tumors of 7 patients, there was no local tumor recurrence. Surgical intervention was considered unnecessary in all cases after the diagnosis of an intraosseous lipoma was determined by MRI.

Soft-tissue osteochondroma in the calcaneal pad: a case report

Soft-tissue osteochondromas of the foot are infrequently occurring lesions. A 65-year-old woman presented with soft-tissue osteochondroma in the soft tissues superficial to the plantar aspect of the calcaneus. The mass was densely ossified without cortical destruction or other alteration in the adjacent calcaneal bone on x-rays and computed tomography images. A 99m Tc bone scan showed a focal area of an increased uptake at the site of the mass below the calcaneus. Magnetic resonance imaging demonstrated high signal mass on T1-weighted images, isointense to fatty marrow, adjacent to the thickened plantar aponeurosis. The mass was completely excised. Histologically, mature lamellar bone was seen centrally, and the periphery was capped with hyaline cartilage. Since the tumor was located in the plantar aponeurosis and comprised of a single nodule of well-developed bone with well-organized endochondral ossification, the pathogenesis of this lesion might be related to metaplasia.

Hematogenous osteomyelitis of the calcaneus in children

Fourteen children (average 9 years) with primary hematogenous osteomyelitis of the calcaneus are reported. Four were seen early and 10 late. Clinical presentation was dramatic, with fever, pain, swelling, and fluctuance around the foot and ankle. The diagnosis was missed initially in 8 cases because the patients were treated for septic arthritis of the ankle, cellulitis, and subcutaneous abscess. The 4 patients seen early healed well, with no complications. The 10 patients seen late had chronic osteomyelitis with growth arrest; shortening of the foot; limb length deficiency; fusion of subtalar, calcaneocuboid, and ankle joints; calcaneus and equinus deformity; avascular necrosis of the talus; and phalangeal loss. Hospital stay was prolonged in 4 patients. Total calcanectomy (3 patients) and talectomy (2 patients) with heel pad preservation were useful salvage procedures avoiding ablation of the limb in chronic cases.

Multiple stress fractures in a young girl with chronic idiopathic arthritis. Extended case report

The occurrence of stress fractures in patients with long-standing rheumatoid arthritis (RA) is widely known. Osteoporosis, corticosteroid therapy, joint stiffness, contracture, angular deformity of the joint and failed joint reconstruction--all together or separately--predispose to bone loss and stress fractures. In the present report we describe the history of a girl with juvenile idiopathic arthritis (JIA) having multiple stress fractures. The relationship between corticosteroid therapy and immobilisation in the treatment of fractures is discussed.

Quantitative ultrasound and trabecular architecture in the human calcaneus

Relationships between quantitative ultrasound (QUS), density (bone volume density [BV/TV]), and trabecular architecture were investigated in 69 calcaneal cancellous bone cubes. Ultrasound signal velocity, phase velocity, attenuation, and broadband ultrasonic attenuation (BUA) measurements were made along the mediolateral axis. Density and architectural parameters were measured using microcomputed tomography (microCT). Density yielded the best correlations with QUS (r2 = 73-77%). Of the individual architectural parameters, correlations with QUS were highest for the Structure Model Index (SMI), a parameter quantifying the relative proportion of rods and plates (r2 = 57-63%). After adjustment for density, significant associations with QUS remained for SMI, trabecular spacing (Tb.Sp), and trabecular number (Tb.N), although the variance in QUS attributable uniquely to individual architectural parameters was at best 4%. In multivariate regression models, combinations of density and architectural parameters explained 76-82% of the variance in QUS, representing an r2 increase of, at most, 8% compared with using density alone. However, multivariate models using combinations of architectural parameters alone (i.e., density excluded) also had a good predictive ability for QUS (r2 = 73-81%). Thus, although these data show modest but significant density-independent relationships between QUS and trabecular architecture in the human calcaneus for the first time, the causal relationships behind the variation in acoustic properties remain obscure. Given the relative weakness and complexity of the emerging associations between QUS and architecture, it is prudent to regard QUS measurements in calcaneal bone primarily as an indicator of bone density.