Interobserver and Intraobserver Reliability in the Radiologic Assessment of Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort study comparing intraobserver and interobserver reliability of 3 different radiologic fusion classifications following uninstrumented single-level anterior lumbar interbody fusion. OBJECTIVE OF THE STUDY: The objective of the study was to compare the intraobserver and interobserver reliability of 3 different radiologic spinal fusion scoring systems. SUMMARY OF BACKGROUND DATA: Knowledge regarding radiologic spinal fusion is crucial when studying patients that were treated with lumbar interbody fusion. The scoring system should be reliable and reproducible. Various radiologic classification systems coexist, but the reliability of these systems has thus far not been compared in a single consecutive group of patients. The aim of the present study was the identification of the most valid scoring system in the assessment of interbody fusion. METHODS: We studied a retrospective consecutive cohort of 50 patients who underwent an anterior lumbar interbody fusion procedure by a single surgeon using a stand-alone cage performed between 1993 and 2002. Plain anterior-posterior, lateral radiographs, and flexion-extension radiographs were made during follow-up visits and were used for analysis. The interbody fusion was scored on these radiographic images using the 3 classification systems (Brantigan, Burkus, and the Radiographic Score) by 2 experienced musculoskeletal radiologists and 2 senior orthopedic spinal surgeons all of whom were blinded to clinical data and outcome. RESULTS: Of the 3 classifications included in the current study, the Burkus classification had a moderate interobserver agreement and a substantial to perfect intraobserver agreement. The other classifications (Bratingan and the Radiographic Score) showed only fair interobserver agreement and moderate to substantial agreement among all observers. No significant differences in reliability between orthopedic surgeons and radiologists were found for all 3 classifications. CONCLUSIONS: The Burkus classification system was classified as most reliable in this, but showed only moderate interobserver agreement. Therefore, the need for a more reliable classification system for the radiographic assessment of lumbar interbody fusion still exists to date.

Poor Radiological and Good Functional Long-term Outcome of Surgically Treated Scheuermann Patients.

STUDY DESIGN: Cohort study. OBJECTIVE: To analyze long-term clinical and radiological outcomes of surgically treated Scheuermann patients. SUMMARY OF BACKGROUND DATA: Long-term clinical and radiological outcomes of surgery for Scheuermann kyphosis are unknown. A single-center cohort of 33 consecutive, surgically treated (between 1991 and 1998) Scheuermann patients was studied. METHODS: Clinical and radiological data of 29 surgically treated Scheuermann patients were collected (posterior approach n = 13; combined anterior-posterior procedure n = 16), after a mean follow-up of 18 years. Oswestry Disability Index (ODI) scores were measured preoperatively (PRE) and twice postoperatively: 2 to 8 years postoperative (FU 1) and 14 to 21 years postoperative (FU 2). Visual Analog Score pain, Short Form-36 (SF-36), and EQ-5d scores were recorded at FU 2 only. Radiographs were analyzed for correction, distal and proximal junctional kyphosis, and implant failures. RESULTS: Mean preoperative kyphosis of the corrected levels was 76° (range 60°-105°) and decreased to a Cobb of 58°(range 30°-105°) at FU 2. Median Visual Analog Score was 2.5 points (range 0-8) and median ODI score was 12 (range 0-62) at FU 2. The ODI score at FU 1 was significantly better as compared to PRE (P < 0.001) and FU 2 (P < 0.001). Also, anterior-posterior treated group had a significantly better ODI score as compared to the posterior-only group (P = 0.023). EQ-5d scores on mobility, usual activities, and pain/discomfort were worse compared to an age-matched population control group; however, SF-36 outcome scores were comparable.Proximal junctional kyphosis was present in 53% of patients, distal junctional kyphosis did not occur, and implant failure/removal had occurred in 69% of patients. Radiological complications do not relate with the ODI, EQ-5d, and SF-36 and 72% of the patients were satisfied. CONCLUSION: Radiological results of this cohort were disappointing but did not relate to clinical outcome scores. Even lumbar pain could not prevent a high patient satisfaction and quality of life. Patients treated with a combined anterior-posterior approach tended to perform better. LEVEL OF EVIDENCE: 3.

Effective nonoperative treatment in juvenile idiopathic scoliosis.

Nonoperative management of juvenile idiopathic scoliosis (JIS) has been reported to be less effective than that of infantile idiopathic scoliosis. The goal of this study was to analyse the results of casting and/or bracing in JIS. Clinical data from seven patients with JIS, treated with casting followed by bracing (n=3) or by bracing alone (n=4), were retrospectively collected, and curve severity was measured before, during and after treatment. The median Cobb angle decreased from 37° to 25°. No patient needed surgery at a median follow-up of 4.6 years (3.4-9.1 years). Casting and/or bracing is effective for the management of JIS.

Prosthetic joint-associated infections treated with DAIR (debridement, antibiotics, irrigation, and retention): analysis of risk factors and local antibiotic carriers in 91 patients.

BACKGROUND AND PURPOSE: For prosthetic joint-associated infection (PJI), a regimen of debridement, antibiotics, irrigation, and retention of the prosthesis (DAIR) is generally accepted for acute infections. Various risk factors associated with treatment success have been described. The use of local antibiotic carriers (beads and sponges) is relatively unknown. We retrospectively analyzed risk factors in a cohort of patients from 3 hospitals, treated with DAIR for PJI. PATIENTS AND METHODS: 91 patients treated with DAIR for hip or knee PJI in 3 Dutch centers between 2004 and 2009 were retrospectively evaluated. The mean follow-up was 3 years. Treatment success was defined as absence of infection after 2 years, with retention of the prosthesis and without the use of suppressive antibiotics. RESULTS: 60 patients (66%) were free of infection at follow-up. Factors associated with treatment failure were: a history of rheumatoid arthritis, late infection (> 2 years after arthroplasty), ESR at presentation above 60 mm/h, and infection caused by coagulase-negative Staphylococcus. Symptom duration of less than 1 week was associated with treatment success. The use of gentamicin sponges was statistically significantly higher in the success group, and the use of beads was higher in the failure group in the univariate analysis, but these differences did not reach significance in the logistic regression analysis. Less surgical procedures were performed in the group treated with sponges than in the group treated with beads. INTERPRETATION: In the presence of rheumatoid arthritis, duration of symptoms of more than 1 week, ESR above 60 mm/h, late infection (> 2 years after arthroplasty), and coagulase-negative Staphylococcus PJI, the chances of successful DAIR treatment decrease, and other treatment methods should be considered.

WEE1 inhibition sensitizes osteosarcoma to radiotherapy.

BACKGROUND: The use of radiotherapy in osteosarcoma (OS) is controversial due to its radioresistance. OS patients currently treated with radiotherapy generally are inoperable, have painful skeletal metastases, refuse surgery or have undergone an intralesional resection of the primary tumor. After irradiation-induced DNA damage, OS cells sustain a prolonged G(2) cell cycle checkpoint arrest allowing DNA repair and evasion of cell death. Inhibition of WEE1 kinase leads to abrogation of the G(2) arrest and could sensitize OS cells to irradiation induced cell death. METHODS: WEE1 expression in OS was investigated by gene-expression data analysis and immunohistochemistry of tumor samples. WEE1 expression in OS cell lines and human osteoblasts was investigated by Western blot. The effect of WEE1 inhibition on the radiosensitivity of OS cells was assessed by cell viability and caspase activation analyses after combination treatment. The presence of DNA damage was visualized using immunofluorescence microscopy. Cell cycle effects were investigated by flow cytometry and WEE1 kinase regulation was analyzed by Western blot. RESULTS: WEE1 expression is found in the majority of tested OS tissue samples. Small molecule drug PD0166285 inhibits WEE1 kinase activity. In the presence of WEE1-inhibitor, irradiated cells fail to repair their damaged DNA, and show higher levels of caspase activation. The inhibition of WEE1 effectively abrogates the irradiation-induced G(2) arrest in OS cells, forcing the cells into premature, catastrophic mitosis, thus enhancing cell death after irradiation treatment. CONCLUSION: We show that PD0166285, a small molecule WEE1 kinase inhibitor, can abrogate the G(2) checkpoint in OS cells, pushing them into mitotic catastrophe and thus sensitizing OS cells to irradiation-induced cell death. This suggests that WEE1 inhibition may be a promising strategy to enhance the radiotherapy effect in patients with OS.

Replacement of native adenovirus receptor-binding sites with a new attachment moiety diminishes hepatic tropism and enhances bioavailability in mice.

The in vivo efficacy of adenoviral vectors (AdVs) in gene delivery strategies is hampered by the broad tissue tropism of the virus and its efficient binding to human erythrocytes. To circumvent these limitations, we developed a prototype AdV lacking native binding sites. We replaced the adenoviral fiber with a chimeric molecule consisting of the fiber tail domain, the reovirus sigma1 oligomerization domain, and a polyhistidine tag as model targeting moiety. We also abolished the integrin-binding motif in the penton base protein. The chimeric attachment molecule was efficiently incorporated onto AdV capsids, allowed efficient propagation of AdV without requirement for complementing fiber and conferred highly specific tropism to the AdV. Importantly, the targeted AdV exhibited markedly reduced tropism for liver cells. In comparison with control AdV with native tropism, the targeted AdV showed 1000-fold reduced transduction of HepG2 cells and 10,000-fold reduced transduction of mouse liver cells in freshly isolated liver slices. After intravenous inoculation of C57BL/6 mice, the targeted AdV exhibited delayed clearance in comparison with the native AdV, leaving approximately 10-fold greater levels in the blood 2 hr after inoculation. For all tissues analyzed, the targeted AdV displayed significantly reduced in vivo transduction in comparison with the native vector. Furthermore, in contrast to the native AdV, the targeted AdV did not bind human erythrocytes. Together, our findings suggest that the targeted AdV design described here provides a promising platform for systemic in vivo gene delivery.

Intravenous administration of the conditionally replicative adenovirus Ad5-Delta24RGD induces regression of osteosarcoma lung metastases.

Metastatic osteosarcoma (OS) has a very poor prognosis. New treatments are therefore wanted. The conditionally replicative adenovirus Ad5-Delta24RGD has shown promising anti-tumor effects on local cancers, including OS. The purpose of this study was to determine whether intravenous administration of Ad5-Delta24RGD could suppress growth of human OS lung metastases. Mice bearing SaOs-lm7 OS lung metastases were treated with Ad5-Delta24RGD at weeks 1, 2 and 3 or weeks 5, 6 and 7 after tumor cell injection. Virus treatment at weeks 1-3 did not cause a statistically significant effect on lung weight and total body weight. However, the number of macroscopic lung tumor nodules was reduced from a median of >158 in PBS-treated control mice to 58 in Ad5-Delta24RGD-treated mice (p = 0.15). Moreover, mice treated at weeks 5-7 showed a significantly reduced lung weight (decrease of tumor mass, p < 0.05), a significantly increased body weight gain (decrease of disease symptoms, p < 0.005) and a reduced number of macroscopic lung tumor nodules (median 60 versus > 149, p = 0.12) compared to PBS treated control animals. Adenovirus hexon expression was detected in lung tumor nodules at sacrifice three weeks after the last intravenous adenovirus administration, suggesting ongoing viral infection. These findings suggest that systemic administration of Ad5-Delta24RGD might be a promising new treatment strategy for metastatic osteosarcoma.

Enhanced tumor cell kill by combined treatment with a small-molecule antagonist of mouse double minute 2 and adenoviruses encoding p53.

Strategies to treat cancer by restoring p53 tumor suppressor functions are being actively investigated. These approaches range from expressing an exogenous p53 gene in p53 mutant cancers to antagonizing a p53 inhibitor in p53 wild-type (WT) cancer cells. In addition, exogenous p53 is used to strengthen the anticancer efficacy of oncolytic adenoviruses. Many cancers express high levels of the major negative regulator of p53, mouse double minute 2 (MDM2) protein. Recently, a novel class of highly potent and specific MDM2 antagonists, the Nutlins, was identified. We envisioned that Nutlins could protect both endogenous and exogenous p53 from MDM2-mediated inactivation. We therefore investigated treating human cancer cells with a combination of adenovirus-mediated p53 gene therapy and Nutlin. Combination treatment resulted in broadly effective cell kill of p53 WT and p53-negative cancer cells. Cytotoxicity was associated with profound cell cycle checkpoint activation and apoptosis induction. We also tested Nutlin in combination with oncolytic adenoviruses. Nutlin treatment accelerated viral progeny burst from oncolytic adenovirus-infected cancer cells and caused an estimated 10- to 1,000-fold augmented eradication of p53 WT cancer cells. These findings suggest that Nutlins are promising compounds to be combined with p53 gene therapy and oncolytic virotherapy for cancer.

A conditionally replicating adenovirus with strict selectivity in killing cells expressing epidermal growth factor receptor.

Virotherapy of cancer using oncolytic adenoviruses has shown promise in both preclinical and clinical settings. One important challenge to reach the full therapeutic potential of oncolytic adenoviruses is accomplishing efficient infection of cancer cells and avoiding uptake by normal tissue through tropism modification. Towards this goal, we constructed and characterized an oncolytic adenovirus, carrying mutated capsid proteins to abolish the promiscuous adenovirus native tropism and encoding a bispecific adapter molecule to target the virus to the epidermal growth factor receptor (EGFR). The new virus displayed a highly selective targeting profile, with reduced infection of EGFR-negative cells and efficient killing of EGFR-positive cancer cells including primary EGFR-positive osteosarcoma cells that are refractory to infection by conventional adenoviruses. Our method to modify adenovirus tropism might thus be useful to design new oncolytic adenoviruses for more effective treatment of cancer.

Replication-dependent transgene expression from a conditionally replicating adenovirus via alternative splicing to a heterologous splice-acceptor site.

BACKGROUND: Oncolytic viruses are promising anticancer agents because they selectively kill cancer cells and multiply within a tumor. Their oncolytic potency might be improved by expressing a therapeutic gene from the virus genome. In this regard, proper kinetics and level of transgene expression are important. In addition, expression of cytotoxic transgene products should be confined to cancer cells. Here, we developed oncolytic adenoviruses that provide transgene expression dependent on viral replication. METHODS: We constructed an oncolytic adenovirus that expresses luciferase under regulation of the endogenous major late promoter (MLP) via alternative splicing to an inserted splice-acceptor site analogous to that of the adenovirus serotype 40 long fiber gene. Splicing of the luciferase transcript was studied by RT-PCR analysis. Expression was measured in the presence and absence of the flavonoid apigenin, an inhibitor of viral replication. RESULTS: The inserted splice-acceptor site was properly recognized by the adenoviral splicing machinery. Luciferase expression levels were markedly higher than levels obtained with the cytomegalovirus (CMV) promoter, especially at late stages of infection. Inhibiting adenovirus replication reduced luciferase expression levels dramatically by 4 to 5 logs, whereas expression levels with the CMV-luciferase adenovirus were only moderately affected (2 logs). CONCLUSIONS: Transgene delivery using the endogenous late gene expression machinery resulted in an expression pattern distinct from expression driven by the conventional CMV promoter. The high expression levels and strict coupling of expression to viral replication should be useful for adequate monitoring of replication and might provide a platform for the design of armed conditionally replicating adenoviruses (CRAds) with enhanced oncolytic potency.

Classical Scheuermann disease in male monozygotic twins: further support for the genetic etiology hypothesis.

STUDY DESIGN: Classic cases of Scheuermann disease in male monozygotic twins are reported. OBJECTIVES: To report classic cases of Scheuermann disease or Scheuermann kyphosis in male monozygotic twins, and to discuss the previous two cases of classic Scheuermann disease in monozygotic twins and the genetic etiology theory of Scheuermann kyphosis. SUMMARY OF BACKGROUND DATA: The etiology of Scheuermann disease remains unclear. Both genetic and mechanical factors or a combination of the two have been postulated to explain Scheuermann disease. The genetic etiology hypothesis has been explained by an autosomal dominant inheritance pattern. In support of this genetic etiology hypothesis, two cases of Scheuermann disease in monozygotic twins have been reported in the English literature. METHODS: The criteria of Sørensen and Sachs et al were used to diagnose Scheuermann kyphosis. Clinical examination and lateral spinal radiographs were performed on a male monozygotic twin. Both parents were clinically investigated for signs of a kyphotic deformity. RESULTS Scheuermann disease was noted in both patients at the same vertebral levels. The Cobb angle of the kyphosis was 74 degrees and 48 degrees, respectively. Clinical examination of both parents did not show any kyphotic abnormality. CONCLUSIONS: These cases of classic Scheuermann disease in monozygotic male twins support the theory that there is a genetic contribution in classic Scheuermann disease.

Nocardia farcinica spinal osteomyelitis.

STUDY DESIGN: A case of disseminated Nocardia farcinica infection with spine involvement is reported. OBJECTIVE: To describe the first case of Nocardia farcinica spinal osteomyelitis, and to propose spine instrumentation with debridement and multiple antibiotics for treatment of nocardia spinal osteomyelitis. SUMMARY OF BACKGROUND DATA: Only 11 cases involving Nocardia asteroides spinal osteomyelitis have been reported over the past 40 years. These case reports describe various presentations and treatments of nocardia spinal osteomyelitis. METHODS: A 54-year-old nonambulant, paraparetic man was admitted to the authors' hospital with acutely increased low back pain, fever, and signs of dementia. A disseminated Nocardia farcinica infection including spinal osteomyelitis at T11, T12, L1, L2, and L4; epidural abscess T10-L4, L5-S1 discitis, empyemas, cerebral abscess, and bilateral psoas abscess was noted. RESULTS: Antibiotic therapy, multiple debridements, and posterior instrumentation were performed to palliate the Nocardia farcinica infection. At a recent 3-year follow-up assessment, the patient was independent and ambulant. He had been off antibiotics for 5 months. CONCLUSIONS: Previous case reports of nocardia spinal osteomyelitis describe treatment with antibiotics, debridements, and arthrodesis with autologous bone graft. Prolonged recumbency ensued. In the reported case, a combination of antibiotics, debridements, arthrodesis, and posterior instrumentation for immediate stabilization of the spine resulted in a favorable outcome at 3 years.