Administrative claims databases have large samples and high generalizability. They have been used to evaluate associations of atypical femoral fractures with bisphosphonates. We developed and assessed accuracy of claims-based algorithms with hospital and physician diagnosis codes for these fractures. Medical records and radiology reports of all adults admitted at University of Alabama at Birmingham Health System from 2004 to 2008 with International Classification of Diseases, Ninth Revision hospital discharges and surgeons' fracture repair codes for subtrochanteric femoral fractures and random sample of other femoral fractures were reviewed. We identified 137 persons with suspected subtrochanteric femoral fractures and randomly selected 50 persons with either suspected diaphyseal femoral fractures or hip fractures other than subtrochanteric and diaphyseal femoral fractures (typical hip fractures). Eleven patients had radiographic features indicative of atypical femoral fractures. The positive predictive value (PPV) of claims-based algorithms varied with primary or secondary positions on discharge diagnoses and the sources of diagnosis codes. The PPV for fractures ranged 69-89% for subtrochanteric femoral, 89-98% for diaphyseal femoral, and 85-98% for typical hip fractures. The PPV of administrative codes for defining a femoral fracture as atypical was low and imprecise. Claims-based algorithms combining hospital discharges with surgeon's diagnosis codes had high PPV to identify the site of subtrochanteric or diaphyseal femoral fractures vs typical hip fractures. However, claims-based data were not accurate in identifying atypical femoral fractures. These claims algorithms will be useful in future population-based observational studies to evaluate associations between osteoporosis medications and subtrochanteric and diaphyseal femoral fractures.

Percutaneous radiofrequency ablation is the treatment of choice for osteoid osteoma of the appendicular skeleton. However, difficulties in localizing the lesion in the spine and its proximity to neural elements have yet to make it the prevalent treatment for spine. This study assesses the safety and effectiveness of two percutaneous techniques for ablating osteoid osteoma of the spine. Seven patients were treated between 1998 and 2005. Four patients underwent percutaneous radiofrequency coagulation. The lesions were located at the articular processes of L3 and L4, the lamina of L3 and in the head of the 11th rib. Three patients with lesions in close proximity to neural structures (pedicle of T9, the posterolateral inferior aspect of L3 vertebral body and the inferior articular process of C5) were subjected to percutaneous core excision. Mean follow-up was 4.2 +/- 1.6 years. Three out of four patients who underwent radiofrequency ablation had an immediate and sustained response. One patient with a lesion in the head of the rib failed to respond. The three patients in the group of pecutaneous core excisional biopsy demonstrated immediate relief of pain. However, one patient experienced relapse of symptoms 6 months after transpedicular core excision. CT scan suggested partial targeting of the lesion that corroborated with histologic examination revealing only reactive tissue. Subsequent percutaneous core excision was successful. Therefore, the overall success rate was 85.7%. Mean VAS improved dramatically from 9 +/- 1 to 2 +/- 1 after surgery (P < 0.05). No neurological or other complications were encountered. This study indicates that radiofrequency ablation of spinal osteoid osteomas is safe and reasonably effective when an intact cortical shell separates the nidus from the neural elements. Percutaneous core excision can obviate the risk of thermal damage for lesions located in close proximity to the neural elements. Effectiveness of treatment can also be evaluated by CT scan and histological examination. Difficulties in targeting the nidus can lead to treatment failure. The minimal morbidity and the effectiveness of these minimally invasive procedures make them a valid alternative in the treatment of spinal osteoid osteoma.

Although autogenous bone graft remains the gold standard graft material, it is associated with an unacceptably high incidence of morbidity. Furthermore, operative time, blood loss, and length of hospitalization are often increased. In order for a graft substitute to replicate the optimal bone healing properties of autogenous graft, 3 essential elements must be present: scaffolding for osteoconduction, growth factors for osteoinduction, and progenitor cells for osteogenesis. A composite graft that combines a synthetic scaffold with osteoprogenitor cells from bone marrow aspirate (BMA) may potentially deliver the advantages of autogenous bone grafts without the procurement morbidity. Sixty consecutive patients with cavitary bone defects were treated with a composite of b-tricalcium phosphate (beta-TCP), Vitoss (Orthovita, Malvern, Pennsylvania), and BMA. The cavitary defects were measured on orthogonal views by experienced musculoskeletal radiologists. Radiographically, resorption and trabeculation increased steadily with time. This differential was slightly more noticeable in large defects with a central trabeculation occurring in advance of the peripheral region. The majority of patients progressed to unrestricted activities by 6 weeks and had returned to their usual activities by 12 weeks. No significant difference in graft incorporation rate was noted based on age, size of defect, or use of adjuvant local treatment. The use of a composite graft (ultraporous beta-TCP+BMA) in the treatment of cavitary lesions appears to be safe and effective.

Synovial sarcoma is a characteristic subtype of soft tissue sarcomas with a predilection for young people. There may be a long delay in diagnosis or misdiagnosis, because of its insidious growth, varied presentation on imaging studies and associated joint pain, which can be confused with trauma. Diagnosis requires a tissue sample in the form of a needle or open biopsy. The needle biopsy may not be representative of the tumor, particular if it is biphasic, and it may be necessary to proceed to open biopsy. Ideally, the biopsy should be performed by the surgeon who will be performing the definitive surgical resection. Although treatment is predicated on surgery, adjuvant radiation and/or chemotherapy may be beneficial, particularly in high risk patients. Significant prognostic factors include: size > 5 cm, deep-seated location, adequacy of surgical margins, and history of recurrence. In the future, multi-institutional prospectively randomized, controlled studies will be needed to better define the role of adjuvant chemotherapy. Currently, outcome may be optimized by early suspicion and detection with referral to an orthopedic oncology specialist prior to the biopsy.

BACKGROUND:Although there are many in vivo studies evaluating lumbar disc injections, no studies have described the occurrence of intravascular uptake of contrast on discography. This phenomenon, however, has been well documented for other fluoroscopically-guided, contrast-enhanced spinal injections.OBJECTIVES:To document the phenomenon and incidence of intravascular uptake during fluoroscopically-guided, contrast-enhanced lumbar disc injections.DESIGN:A prospective, observational, community-based study.METHODS:The incidence of fluoroscopically-confirmed intravascular uptake of contrast material was documented in 160 patients representing a subset of individuals presenting to a small private community hospital for evaluation and treatment of lower back pain. These patients underwent fluoroscopically-guided lumbar disc injections for therapeutic and/or diagnostic purposes.RESULTS:A total of 280 discs from L1-2 to L5-S1 were studied. The degree of disc degeneration of the evaluated discs was scored using the Adams' scoring criteria for intervertebral disc degeneration. The incidence of intravascular uptake as well as any correlation between stage of disc degeneration and intravascular uptake was statistically evaluated. A total of 40 out of 280 discs (14.3%) demonstrated intravascular uptake. Detection of intravascular uptake usually required real-time fluoroscopy. There was no statistical correlation between the degree of disc degeneration and the incidence of intravascular uptake. No disc infections or other adverse sequelae occurred.CONCLUSION:This is the first study, to our knowledge, that addresses the incidence of intravascular uptake during lumbar disc injections in patients with low back pain. The presence of intravascular uptake may have implications both clinically and diagnostically in regards to interpretation of lumbar discography and adverse events related to loss of injected medications into the vascular system.

OBJECTIVE:This study evaluates the safety and outcome of a minimally invasive technique for inserting a standard dynamic hip screw for intertrochanteric fractures.HYPOTHESIS:The use of standard plate in a minimally invasive technique is both possible and advantageous to patient outcome.DESIGN AND METHODS:Prospective surgeon-randomized blinded outcome clinical study comparing new technique to conventional technique.MAIN OUTCOME MEASURE:Pain, operative time and mean hemoglobin drop in percutaneous hip fixation.RESULTS:The minimally invasive technique had significantly less blood loss (P < 0.001), operative time (P < 0.001) and a trend to less morphine use.CONCLUSIONS:Minimal invasive technique significantly reduces blood loss and operative time for fixation of intertrochanteric hip fractures without sacrifice of fixation stability or bone healing.

JEFFREY R. CURTIS, MD, MPH, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham; PHILIP H. LANDER, MD, Department of Radiology, University of Alabama at Birmingham; LARRY W. MORELAND, MD, Arthritis Clinical Intervention Program, University of Alabama at Birmingham, Birmingham, Alabama, USA. Address reprint requests to Dr. J.R. Curtis, Division of Clinical Immunology and Rheumatology, UAB FOT 840, 510 20th Street South, Birmingham, AL 35294. E-mail: jeffrey.curtis@ccc.uab.edu

Seventy-one percutaneous transpedicle biopsy specimens were taken from 68 patients with cervical, thoracic, lumbar, or sacral vertebral lesions, with the patients under local anesthesia. Sixty-one procedures were done with fluoroscopic guidance and seven procedures were done with computed tomography guidance. Twenty-one patients were diagnosed as having infectious spondylodiscitis, three had tuberculosis, two had coccidiomycosis, two had brucellosis, one had blastomycosis, one had an echinococcus cyst, six had primary neoplasms, 14 had metastatic neoplasms, five had osseous repair for insufficiency fractures, seven had osteoporotic fractures, and one had Paget's disease of bone. In the four remaining patients, the biopsy initially was negative but it was proven to be false-negative because of faulty biopsy technique. The percutaneous transpedicle approach for biopsy is safe, efficacious, and cost-effective. False-negative results and complications can be avoided when adhering to the technical details of this procedure.

Seventy-one percutaneous transpedicle biopsy specimens were taken from 68 patients with cervical, thoracic, lumbar, or sacral vertebral lesions, with the patients under local anesthesia. Sixty-one procedures were done with fluoroscopic guidance and seven procedures were done with computed tomography guidance. Twenty-one patients were diagnosed as having infectious spondylodiscitis, three had tuberculosis, two had coccidiomycosis, two had brucellosis, one had blastomycosis, one had an echinococcus cyst, six had primary neoplasms, 14 had metastatic neoplasms, five had osseous repair for insufficiency fractures, seven had osteoporotic fractures, and one had Paget’s disease of bone. In the four remaining patients, the biopsy initially was negative but it was proven to be false-negative because of faulty biopsy technique. The percutaneous transpedicle approach for biopsy is safe, efficacious, and cost-effective. False-negative results and complications can be avoided when adhering to the technical details of this procedure.

The presence of infectious spondylodiskitis and its complications may present protean clinical and imaging findings. The frequent use of multi-imaging modalities has led to a greater sensitivity and specificity in the diagnosis of this ubiquitous disease.

A review of the literature was conducted to study the pathomechanics by which Paget's Disease of bone (PD) alters the spinal structures that result in distinct spinal pathologic entities such as pagetic spinal arthritis, spinal stenosis, and other pathologies, and to assess the best treatment options and available drugs. The spine is the second most commonly affected site with PD. About one-third of patients with spinal involvement exhibit symptoms of clinical stenosis. In only 12-24% of patients with PD of the spine is back pain attributed solely to PD, while in the majority of patients back pain is either arthritic in nature or a combination of a pagetic process and coexisting arthritis. Neural element dysfunction may be attributed to compressive myelopathy by pagetic bone overgrowth, pagetic intraspinal soft tissue overgrowth, ossification of epidural fat, platybasia, spontaneous bleeding, sarcomatous degeneration and vertebral fracture or subluxation. Neural dysfunction can also result from spinal ischemia, when blood is diverted by the so-called "arterial steal syndrome". Because the effectiveness of pharmacologic treatment for pagetic spinal stenosis has been clearly demonstrated, surgical decompression should only be instituted after failure of antipagetic medical treatment. Surgery is indicated as a primary treatment when neural compression is secondary to pathologic fractures, dislocations, spontaneous epidural hematoma, syringomyelia, platybasia, or sarcomatous transformation. Since, in the majority of cases with pagetic spinal involvement, there are also coexisting osteoarthritic changes, antipagetic medical treatment alone may be disappointing. Therefore, one must be careful before attributing low back pain to PD alone. Five classes of drugs are available for the treatment of PD: bisphosphonates, calcitonins, mithramycin (plicamycin), gallium nitrate, and ipriflavone. Bisphosphonates are the most popular, and several forms have been investigated, but only the following forms have been approved for clinical use: disodium etidronate, clodronate, aledronate, risedronate, neridronate, pamidronate, tiludronate, ibadronate, aminohydroxylbutylidene bisphosphonate, olpadronate, and zoledronate. Several of these forms are still under investigation.

The purpose of this study is to evaluate the relation of bone mineral density (BMD) or the age-matched z score and osteoporotic vertebral fractures. The radiographs and spinal bone mineral density of 131 consecutive postmenopausal patients were retrospectively reviewed. The vertebral fractures between T4 and L4 were graded. Sixty-two patients had no fractures, and 69 had 1 or more fractures. In the nonfracture group, the mean age was 62.6 years, BMD was 0.88 g/cm2, and the z score was -1.00. In the fracture group, the mean age was 69.6 years, BMD was 0.788 g/cm2, and the z score was -1.26. Patients with 2 and 3 or more fractures had a lower mean BMD than that of the nonfracture group (P < .01). The z score (adjusted for age) was significantly lower only in patients with 3+ fractures (P < .05). Patients with grade 2 and grade 3 of any fracture type had significantly lower BMD (P < .01). The z score was lower only in those with grade 3 fracture (P < .05). Our study indicates that the clinical use of BMD z score adjusted for age is a better predictor of severity of vertebral fractures than is BMD alone.

STUDY DESIGN:An animal study was performed to evaluate lumbar spinal fusion radiologically and mechanically.OBJECTIVES:To assess the efficacy of interconnected porous hydroxyapatite in achieving posterolateral lumbar arthrodesis in sheep.SUMMARY OF BACKGROUND DATA:Posterolateral spinal arthrodesis with autologous bone graft is the gold standard procedure for lumbar fusion. The procedure for harvesting bone from the iliac crest increases morbidity. Interconnected porous hydroxyapatite has been used effectively as an alternative to cancellous bone graft material in metaphyseal bone defects. Little is known about the efficacy of interconnected porous hydroxyapatite in achieving lumbar spinal fusion.METHODS:Four groups of seven sheep underwent bisegmental posterolateral lumbar fusion with instrumentation using different intertransverse graft material. In group 1, no graft material was used. In group 2, autologous bone was used. Group 3 had interconnected porous hydroxyapatite. Group 4 had an equip of interconnected porous hydroxyapatite and autologous bone. The animals were killed at 20 weeks after surgery. Radiographs and computed tomography images were obtained. The fusion masses were graded for bone resorption and trabecular connectivity on the computed tomography images. Mechanical testing of the specimens was performed, and the three-dimensional segmental motion was measured in flexion/extension, axial rotation, and lateral bending.RESULTS:The radiographic images were difficult to interpret because of the radiodense interconnected porous hydroxyapatite granules. According to mechanical stability criteria, the fusion rate for the different groups was as follows: 100% (14/14) for the autologous bone group, 72% (10/14) for the bone/interconnected porous hydroxyapatite group, 50% (7/14) for the pure interconnected porous hydroxyapatite group, and 15% (2/14) for the sham group.CONCLUSIONS:Spinal arthrodesis using interconnected porous hydroxyapatite alone or mixed with bone as graft material reduced segmental motion. It was not, however, as effective as autologous bone graft material in achieving spinal arthrodesis. The sheep model using autologous bone achieved a 100% fusion rate. Because the nonunion rate for a single level in humans may be as high as 40%, the fusion rate with bone/interconnected porous hydroxyapatite in humans may be lower than the 72% found in the sheep model. The little resorption of the radiodense interconnected porous hydroxyapatite granules made the radiologic evaluation of the fusion masses difficult.

s of European Cells and Materials I Bone & Soft tissue Biomaterial interactions August 22nd24th 1999, Congress Centre, Davos, Switzerland

OBJECTIVE:Upright flexion-extension myelography has shown marked variation in the severity of lumbar dural sac stenosis during flexion and extension in some patients ("positionally dependent" stenosis). Axial computed tomography (CT) of the lumbar spine while the patient is supine may not demonstrate the maximal spinal stenosis shown by flexion-extension myelography. This study compares the severity of central lumbar spinal stenosis on CT myelograms and on upright flexion-extension myelograms in patients with positionally dependent spinal stenosis.PATIENTS AND METHODS:From January 1995 to December 1996, 210 patients underwent upright flexion-extension lumbar myelography for the assessment of back pain, radiculopathy or neurogenic claudication. In 33 of these patients (in whom 39 lumbar levels were seen) there was a difference of 30% or more in the diameter of the dural sac seen on anteroposterior lateral myelograms during flexion and extension. These findings were compared with the dural sac compression shown on the CT myelograms for these patients.RESULTS:In 10 of the 33 patients (12 levels), the CT myelogram underestimated spinal stenosis, as compared with the upright flexion-extension myelogram. In 5 levels, stenosis of 70% or more seen on flexion-extension myelography was measured as 50% or less on CT myelography.CONCLUSION:In patients with positionally dependent spinal stenosis, CT myelograms may underestimate the severity of the spinal stenosis, compared with upright flexion-extension myelograms. While upright flexion-extension myelography is not a first-line imaging modality for patients with spinal stenosis, it should be considered for patients whose symptoms are not explained by routine cross-sectional imaging studies to exclude positionally dependent spinal stenosis.