Long-term follow-up of the anterior lumbar interbody fusion procedure.

PURPOSE: To evaluate the long-term clinical results and the effectiveness of the anterior lumbar interbody fusion procedure. METHODS: Between 1999 and 2005, 60 ALIFs were performed in 59 patients. Mean age was 41.1 years. Clinically, patients were evaluated at a mean follow-up of 9.5 years using the Visual Analogue Scale grading scale, the Oswestry Disability score and the SF-36 questionnaire. RESULTS: Preoperative and postoperative clinical evaluation scores of 38 patients were available. Nineteen patients were lost to follow-up, and 2 patients died during the follow-up. The fusion rate was 84%. Mean preoperative VAS-score for back pain was 6.69 (±2.15) ; in the long term, the mean VAS-score was 4.95 (±2.95), which was a significant improvement. (p<0.01). The postoperative ODI-score was 36.11 (±22.32), while the preoperative ODI-score was 59.31 (±17.16), which demonstrates a significant improvement. According to the SF-36, mild to good results were observed. CONCLUSIONS: The ALIF procedure can offer significant pain relief and improved function if a strict indication policy is followed.

Extracorporeally irradiated autografts for the treatment of bone tumours: tips and tricks.

We retrospectively reviewed 107 patients with 108 malignant or locally aggressive bone tumours treated between 1978 and 2009 by extracorporeal irradiation with 300 Gy to eradicate the tumour, and reimplantation of the bone as an orthotopic autograft. Patient subgroups were defined according to resection type. We describe the local recurrence rate, the graft infection rate and the factors affecting graft healing and graft survival. No local recurrences were detected in the irradiated grafts. At five-year follow-up, graft healing had occurred in 64% of patients, providing a stable and lasting reconstruction. For various reasons, 11% of grafts were removed, although no single factor was predictive of failure. All patient subgroups had comparable results. Early infection predicted the development of pseudarthrosis. Pelvic reconstructions had a worse graft survival. Rigid fixation and bridging of the graft appeared to be important technical points.

Radiographic analysis of extracorporeally irradiated autografts.

OBJECTIVE: To analyse the long-term radiographic findings of intercalary, pure osteoarticular, and composite bone grafts in patients with primary bone sarcoma who were treated by reimplantation of the bone as an orthotopic autograft. MATERIALS AND METHODS: For this observational clinical study, 107 patients who presented with 108 malignant or locally aggressive benign bone tumours were treated by resection, extracorporeal irradiation (300 Gy), and reimplantation and fixation of the autograft. Bone healing features were evaluated with the International Society of Limb Salvage (ISOLS) graft evaluation method, which assesses fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing, and subchondral bone. A description of normal and abnormal healing patterns and complications comprised the secondary endpoint. RESULTS: Seventy-seven patients with complete radiographic data were selected for review. The mean ISOLS score was 78.2% (range 25.0-100%, median 79.2%). Three patient subgroups were created: intercalary graft, pure osteoarticular graft, and composite reconstruction consisting of an intercalary graft augmented with a prosthesis; the mean ISOLS scores were 81.3%, 70.7%, and 77.4%, respectively. Each item was scored individually, and no significant difference was observed (P = 0.225). CONCLUSION: This reconstruction technique is valid for the three methods described; bone stock is retained and, once the graft has healed, it behaves as normal bone. Close radiographic follow-up detects complications early, allowing timely interventions if necessary.

99mTc ciprofloxacin imaging for the diagnosis of infection in the postoperative spine.

BACKGROUND: The non-invasive assessment of postoperative spinal infections can pose a substantial diagnostic challenge, especially in the presence of orthopaedic devices. In contrast to white blood cell scanning, which is of limited use in the spine, the low uptake of 99mTc ciprofloxacin into normal bone marrow, combined with its claimed bacterial specificity, makes it, theoretically, an ideal candidate for evaluating postoperative spinal infections. AIM: This study aimed to evaluate 99mTc ciprofloxacin planar and single photon emission tomography (SPET) imaging in relation to microbiological diagnosis in the postoperative spine. METHODS: Only patients with a microbiologically confirmed diagnosis were included in this analysis. Planar imaging was performed at 1, 3 and 24 h, and SPET was performed at 3 h post-injection of 370 MBq 99mTc ciprofloxacin. Images were scored by two independent, certified, nuclear medicine physicians, blinded for the final diagnosis. RESULTS: Within the first 22 consecutive patients with microbiological diagnosis, there were nine deep infections. Sensitivity, specificity and accuracy at visual scoring were, respectively, 67%, 77%, 73% (1 h), 78%, 69%, 73% (3 h), and 56%, 92%, 77% (24 h) for planar imaging, and 100%, 54%, and 73% for SPET. CONCLUSION: In contrast to white blood cell scanning, SPET with Tc ciprofloxacin is sensitive in evaluating infections in the postoperative spine. Sensitivity is higher for SPET than for planar imaging. However, the results presented prove that its specificity is limited, especially in patients who have recently (< 6 months) undergone surgery. Taken this limitation into account, we advise planar and SPET imaging at 3 h post-injection and at an interval of at least 6 months after surgery to minimize the chance for false positives.

Are stand-alone cages sufficient for anterior lumbar interbody fusion?

Anterior lumbar interbody fusion (ALIF) has increased in popularity because it has advantages over posterior fusion. Because there is disagreement about the stability of stand-alone cage ALIF, some surgeons use various types of supplementary fixation, including anterior plates, pedicle screw systems and translaminar screws, to increase segmental stability. Many factors associated with both the cages and endplates influence the time of onset and extent of subsidence after use of stand-alone cage ALIF. A large round cage with an adequate central opening is recommended to facilitate maximum contact with the periphery of the endplate. With regard to the relationship between radiographic fusion and recurrence of symptoms with the development of subsidence, most researchers have reported finding no correlation. Subsidence may be due to a process of bone incorporation between cages and endplates. Does subsidence or nonfusion really matter clinically? Further prospective, randomized controlled trials are very much needed to answer these questions.

Tumor grafts derived from sarcoma patients retain tumor morphology, viability, and invasion potential and indicate disease outcomes in the chick chorioallantoic membrane model.

The chick chorioallantoic membrane (CAM) assay was used to evaluate whether xenotransplanted sarcomas retain the histological characteristics and functional behavior of the original tumors. Metabolically active tumor tissue, identified by dynamic-contrast MRI, from 28 patients with a bone or soft-tissue tumors was applied to the CAM. Angiogenesis and graft and host behaviors were evaluated. The essential features and immunohistochemical characteristics of the original tumors were maintained, illustrating the diversity of sarcomas. Graft viability was inversely related to patient survival, but longer follow-up and more patients are needed to relate tumor graft behavior to natural history. We conclude that the CAM assay is a potential prognostic and predictive preclinical xenograft model for tumors that are difficult to culture in vitro, such as sarcomas; therefore, the use of the CAM assay may facilitate personalized medicine.

Comparison of vertebroplasty and kyphoplasty for complications.

Vertebroplasty (VP) and kyphoplasty (KP) have been proven equally effective in providing pain relief in patients with vertebral compression fractures (VCF). Both have been reported to have multiple complications which, though rare, are potentially devastating. This literature review focuses on comparing the incidence of various types of complication of VP and KP. Local cement leakage and pulmonary cement embolism have been reported more commonly after VP than KP. It is questionable whether the relative risk of developing an adjacent level new fracture after VP is greater than after KP The relationship between a new VCF and each of these procedures has also not been clearly established. Although the majority of complications are clinically silent, their potential risks, which include a fatal outcome, should always be kept in mind by the practitioner.

CD33+ CD14- phenotype is characteristic of multinuclear osteoclast-like cells in giant cell tumor of bone.

Giant cell tumor of bone (GCTB) is a benign bone tumor with a shown clinical behavior of local recurrences and rare distant metastases. GCTB is composed of uniformly distributed osteoclastic giant cells, thought to originate from the fusion of monocyte-macrophage lineage cells, in a background consisting of mononuclear rounded cells and spindle-shaped cells. Several reports showed the specific expression of markers, such as CD14 on the mononuclear rounded cell population, however, lacking osteoclastic giant cells. Blood monocytes that were CD14+, CD33+, or CD14+/CD33+ have also been shown to be programmed as pre-osteoclasts. The macrophage marker CD33 is expressed earlier than CD14 in macrophage maturation, whereas CD14 is expressed longer than CD33. The aim of this study was to investigate CD14/CD33 expression profiles in GCTB. Nineteen GCTB tumor samples of 19 patients were studied. Immunofluorescent analyses were performed with monoclonal antibodies against CD14, CD33, RANK, and CD51. To unambiguously further prove the expression of these molecules, quantitative RT-PCR was used with subsequent sequencing of its products. All samples showed similar immunoreactivity profiles. The mononuclear rounded cell population was positive for RANK, CD51, CD14, and CD33. The osteoclastic giant cell population expressed RANK and CD51, as well as CD33, but was consistently negative for CD14 expression. The CD14 and CD33 profiles were confirmed by quantitative RT-PCR. These RT-PCR products were sequence verified. Osteoclasts in GCTB are the result of fusion of CD33-expressing pre-osteoclasts that further fuse with CD14+ mononuclear cells. Although these results reflect a static rather than a dynamic spectrum, we strongly believe that osteoclastogenesis seems not to be the exclusive result of fusion of intratumoral CD14+ mononuclear cells. Moreover, CD33-modulated osteoclastogenesis opens up the possibility for novel therapeutic directions.

Can autologous thrombin with a rest fraction of ethanol be used safely for activation of concentrated autologous platelets applied on nerves?

The use of concentrated platelet-rich plasma (cPRP) as a source of growth factors is reported to be beneficial for an enhanced osteogenesis in spine surgery. Today both bovine and autologous thrombin is used for activating the platelets and thus releasing the growth factors. In order to prevent transmission of organisms and the development of antibodies, autologous thrombin seems to be the logical choice. However, the preparation of autologous thrombin is cumbersome and consumes a part of the cPRP. In order to overcome this problem, a commercial autologous thrombin kit (activAT, Dideco, a Sorin Group company, Italy) has been developed which produces autologous thrombin out of platelet-poor plasma. A possible disadvantage of this kit could be the rest fraction of 1.18% of ethanol in the platelet gel. In a pig model, the influence of different ethanol concentrations on the ischiadic nerve was studied. The study consisted out of four groups; a control group (n=6), a group with platelet gel 0% ethanol (n=6), a group with platelet gel 1.18% ethanol (n=6) and a group with platelet gel 3.8% ethanol (n=7). In all the groups, the ischiadic nerve was dissected and the myelin sheet opened after which the wound was closed (control group) or one of the three therapies was applied. After 12 h, the animal was sacrificed and the ischiadic nerve was submitted for histological examination. Myelin sheaths appeared normal in all cases. No axonal swelling was observed. No statistically significant differences were observed for neutrophilic and eosinophilic infiltration nor for collagen necrosis between groups. Platelet gel prepared by the use of a commercial autologous thrombin kit and containing 1.18% of ethanol can be safely used on nerves.

Extracorporeally irradiated autografts in pelvic reconstruction after malignant tumour resection.

We treated 15 patients suffering from an extracompartmental malignant pelvic tumour by resecting the affected part of the bone, irradiating it extracorporeally with 300 Gy, and reimplanting it after having removed the bulk of the lesion. Adjuvant therapies were used according to the type and extension of the tumour. Follow-up was an average of 4 years 6 months. Complications were seen in 13 patients. Most mechanical complications were related to the use of hip arthroplasties. Internal fixation of the graft failed in one case only, infection was seen in three cases, and seven patients died after local recurrence. Functional scores were fair. Although many complications were seen, this method remains our treatment of choice.

18-Fluorine fluorodeoxyglucose positron emission tomography for the diagnosis of infection in the postoperative spine.

BACKGROUND: Using conventional imaging methods, including magnetic resonance imaging and labeled leukocyte scanning, the diagnosis of infection in the postoperative spine remains a diagnostic challenge. Recently, promising results have been reported using 18F-fluorodeoxyglucose positron emission tomography for various infectious problems. This study aimed to investigate the value of 18F-fluorodeoxyglucose positron emission tomography in patients suspected of having spinal infection after previous surgery of the spine. METHODS: Fifty-seven consecutive patients with a history of previous spinal surgery were prospectively included between February 1999 and June 2001. 18F-fluorodeoxyglucose positron emission tomography was performed 60 to 90 minutes after injection of 370 MBq 18F-fluorodeoxyglucose. Images were scored visually and semiquantitatively by two blinded, independent, certified nuclear medicine physicians, experienced with positron emission tomography. Differences were assessed by consensus. Results were correlated with final diagnosis allowing calculation of sensitivity, specificity and accuracy. Receiver operating characteristic analysis was performed to find optimal cut-off values. RESULTS: Fifteen patients had spinal infection. Using the most sensitive cut-off values sensitivity, specificity and accuracy were 100%, 81%, and 86%, respectively, for both visual and semiquantitative scoring. In the group without metallic implants (n = 27), false positives (n = 2) only occurred in the first 6 months after surgery. In the group with metallic implants (n = 30), false positives (n = 6) were not confined to recently operated patients. CONCLUSIONS: Overall accuracy was excellent (86%) with a negative predictive value of 100%. 18F-fluorodeoxyglucose positron emission tomography holds promise to become the standard imaging technique in this difficult patient population, as it is straightforward, provides a rapid result (2 hours) and because accurate alternatives are lacking.