Published papers

This study aimed to assess the effects of down-sizing and lateralizing of the tibial component (reduction osteotomy) on gap balancing in TKA, and the clinical feasibility of an uncemented modular trabecular metal tibial tray in this technique. Reduction osteotomy was performed for 39 knees of 36 patients with knee OA with a mean tibiofemoral angle of 21° varus. In 20 knees, appropriate gap balance was achieved by release of the deep medial collateral ligament alone. Flexion gap imbalance could be reduced by approximately 1.7° and 2.8° for 4-mm osteotomy and 8-mm osteotomy, respectively. Within the first postoperative year, clinically-stable tibial component subsidence was observed in 9 knees, but it was not progressive, and the clinical results were excellent at a mean follow-up of 3.3years.

Background context: Various factors are reported to affect the spinal alignment in degenerative lumbar scoliosis (DLS). Although trunk muscles also appear to affect spinal alignment, the role of the trunk muscles is not yet clear. Purpose: The aim was to elucidate the role of the multifidus (MF) and psoas (PS) in maintaining global spinal alignment in patients with DLS. Study design: This was a multicenter retrospective matched cohort study. Patient sample: Surgically treated 60 paired DLS and lumbar spinal stenosis (LSS) female (120 patients), matched for age and body mass index (BMI; DLS age 68.0±6.8 vs. LSS 67.1±8.9 years; BMI 21.6±3.3 vs. 23.2±3.8 kg/m2), were included and were followed for at least 2 years. Outcome measures: Spinal alignment, muscle area, and volume were measured from radiographs, magnetic resonance images (MRIs), and whole-body dual-energy X-ray absorptiometry (DXA) scans. Muscle strength was measured by grip power and peak expiratory flow (PEF). Methods: As a surrogate of muscle area, we obtained the cross-sectional area (CSA) at the L5-S level from preoperative MRIs. Results: The MF and PS CSAs were significantly smaller in the DLS group than in the LSS group (MF 477.7±192.5 vs. 779.8±248.6 mm2, p<.01; PS 692.3±201.2 vs. 943.4±272.4 mm2, p=.002), whereas percentage of difference between the right and left sides was significantly larger in the DLS group (MF 18.4±30.6 vs. 2.4±3.3%, p<.01; PS 14.4±15.8 vs. 2.1±2.2%, p<.01). In the extremities, there were no significant differences in the left- or right-side lean composition and grip strength or PEF tests between the groups. Correlation coefficient tests showed moderate correlations between the MF average CSA (avCSA) and global spinal alignment and spinopelvic alignment (pelvic incidence-lumbar lordosis; R=-0.37, -0.38) in the DLS group. The MF avCSA was correlated with the postoperative progression of kyphosis at the unfused thoracic vertebrae in the DLS group (R=0.34). Conclusions: The CSAs of the MF and PS were significantly smaller in the DLS group. Whole-body DXA showed no significant difference in the lean composition between the groups. There were significant correlations in the DLS patients between the MF CSA and sagittal spinal alignment. These findings suggest the causal relationship between muscles and global spine alignment.

Formation of foreign body giant cells (FBGCs) occurs following implantation of medical devices such as artificial joints and is implicated in implant failure associated with inflammation or microbial infection. Two major macrophage subpopulations, M1 and M2, play different roles in inflammation and wound healing, respectively. Therefore, M1/M2 polarization is crucial for the development of various inflammation-related diseases. Here, we show that FBGCs do not resorb bone but rather express M2 macrophage-like wound healing and inflammation-terminating molecules in vitro. We also found that FBGC formation was significantly inhibited by inflammatory cytokines or infection mimetics in vitro . Interleukin-1 receptor-associated kinase-4 (IRAK4) deficiency did not alter osteoclast formation in vitro, and IRAK4-deficient mice showed normal bone mineral density in vivo. However, IRAK4-deficient mice were protected from excessive osteoclastogenesis induced by IL-1β in vitro or by LPS, an infection mimetic of Gram-negative bacteria, in vivo. Furthermore, IRAK4 deficiency restored FBGC formation and expression of M2 macrophage markers inhibited by inflammatory cytokines in vitro or by LPS in vivo. Our results demonstrate that osteoclasts and FBGCs are reciprocally regulated and identify IRAK4 as a potential therapeutic target to inhibit stimulated osteoclastogenesis and rescue inhibited FBGC formation under inflammatory and infectious conditions without altering physiological bone resorption.

Background context Parkinson's disease (PD) is a progressive degenerative disorder of the central nervous system. Patients with PD often present with abnormal posturing.Purpose To investigate coronal plane deformities in patients with PD, and to evaluate the correlation between clinical features, coronal parameters related to spine alignment, and disease severity.Study design A cross-sectional study.Patient sample Eighty-nine patients with PD and 89 controls were included.Outcome measures A medical history was collected from the medical records.Methods This study was a prospective assessment of consecutive patients with PD. Clinical and demographic parameters were collected from medical records and outpatient interviews. Full-length standing anteroposterior and lateral spine radiographs were used to assess the spinal parameters. The threshold for scoliosis was set at a 10° Cobb angle, and the curve type was classified using Schwab classification.Results A total of 178 patients (89 in PD and 89 in control groups) were included. Scoliosis was identified in 27 patients (30%) and 22 controls (p=.502). However, coronal imbalance was more common in patients with PD than in controls (11 vs. 0 patients, p=.001). Scoliosis was more common in women than in men (male:female=8:19, p=.04). Back pain was more common in patients with scoliosis than in those without scoliosis (14 of 27 vs. 17 of 62, p=.036). Schwab Type IV (thoracolumbar major) was the most common type of scoliosis in patients with PD and Type V (lumbar major) was the most common type in controls. With adjustment for patient age and gender, multiple linear regression analysis revealed that severity of PD (Unified Parkinson's Disease Rating Scale, p=.037) and magnitude of global coronal malalignment (p=.003) were associated with the scoliosis Cobb angle (p=.037, B=0.139). Direction of scoliosis and side of global coronal malalignment were not significantly correlated with the laterality of predominant PD symptoms (p>.05).Conclusions Global coronal malalignment is more prevalent in patients with PD than in controls. Greater severity of PD was significantly associated with greater magnitude of scoliosis Cobb angle, even after adjusting for the effects of patient age and gender. However, direction of scoliosis and side of global coronal malalignment were not significantly associated with the dominant laterality of PD symptoms.

STUDY DESIGN.: A retrospective case series.OBJECTIVE.: To assess whether a short fusion strategy is applicable when treating adolescent idiopathic scoliosis with Lenke type 5C curve by posterior correction and fusion surgery using pedicle-screw constructs.SUMMARY OF BACKGROUND DATA.: Previous studies have discussed the selection of the lower instrumented vertebra to best preserve motion segments and obtain coronal balance. However, reports evaluating the selection of the upper instrumented vertebra when treating Lenke type 5C curves are not available.METHODS.: We evaluated 29 patients who were treated surgically for adolescent idiopathic scoliosis with Lenke type 5C curve (mean age, 16.8 ± 4.7 yr; range, 10-29 yr). The mean follow-up period was 28.0 ± 6.3 months (range, 24-48 mo). We compared radiographical parameters and clinical outcomes between patients with an upper instrumented vertebra at the end vertebra (EV) (n = 10) and those treated by short fusion (S group), with a upper instrumented vertebra 1-level caudal to the EV (n = 19 patients).RESULTS.: In the EV group, a preoperative mean Cobb angle of 50°± 15° was corrected to 8°± 7°, which was maintained at the final follow-up (7°± 1°). In the S group, a mean preoperative Cobb angle of 47°± 4° was corrected to 8°± 5°, but this increased significantly to 12°± 7° at final follow-up (P = 0.033). The mean correction rate at final follow-up was significantly lower in the S group (72%) than in the EV group (86%) (P = 0.027). Coronal and sagittal balance, thoracic kyphosis, lumbar lordosis, L4 tilt, and clinical outcomes evaluated by Scoliosis Research Society patient questionnaire-22 were equivalent between the 2 groups.CONCLUSION.: Scoliosis Research Society patient questionnaire-22 scores and radiographical parameters other than the correction rate were equivalent between the 2 groups. A short fusion strategy, in which the upper instrumented vertebra is 1-level caudal to the upper EV, is applicable to posterior correction and fusion surgery with pedicle-screw constructs for Lenke type 5C curves.

We developed a novel antibacterial implant by forming a hydroxyapatite (HAp) film on polyetheretherketone (PEEK) substrate, and then immobilizing silver ions (Ag+) on the HAp film based on the chelate-bonding ability of inositol phosphate (IP6). First, the PEEK surface was modified by immersion into concentrated sulfuric acid for 10 min. HAp film was formed on the acid-treated PEEK via the soft-solution process using simulated body fluid (SBF), urea, and urease. After HAp coating, specimens were immersed into IP6 solution, and followed by immersion into silver nitrite solution at concentrations of 0, 0.5, 1, 5 or 10 mM. Ag+ ions were immobilized on the resulting HAp film due to the chelate-bonding ability of IP6. On cell-culture tests under indirect conditions by Transwell®, MC3T3-E1 cells on the specimens derived from the 0.5 and 1 mM Ag+ solutions showed high relative growth when compared with controls. Furthermore, on evaluation of antibacterial activity in halo test, elution of Ag+ ions from Ag+-immobilized HAp film inhibited bacterial growth. Therefore, the above-mentioned results demonstrated that specimens had both biocompatibility and strong antibacterial activity. The present coating therefore provides bone bonding ability to the implant surface and prevents the formation of biofilms in the early postoperative period.

Low serum 25-hydroxyvitamin D (25(OH)D) levels are implicated as a risk factor for hip and spine fractures. Studies of the relation between 25(OH)D levels and fractures have primarily involved elderly osteoporosis patients or patients with fractures; however, the serum 25(OH)D and parathyroid hormone (PTH) status in younger adult populations remains largely unknown. We evaluated serum 25(OH)D and intact PTH levels in 411 women aged 39–64 years who were not receiving medication for osteoporosis or other bone diseases. Serum 25(OH)D levels were positively correlated with age (P = 0.019), whereas intact PTH levels were inversely correlated with 25(OH)D levels (P <0.001). Thus, low vitamin D levels with high intact PTH levels were more common in younger than in older women. Our data show that serum 25(OH)D insufficiency could be a more serious concern in the younger population than had been previously anticipated. Because serum 25(OH)D insufficiency is reportedly a risk factor for hip and spine fracture, the number of fracture patients could increase in the future, suggesting that we may need to correct the serum vitamin D/intact PTH status to prevent future osteoporosis.

Introduction: Few reports have compared the clinical features and imaging characteristics of giant cell tumor and chordoma of the spine. The aim of the present study was to investigate whether the two types of tumors could be differentially diagnosed, by comparing clinical characteristics as well as magnetic resonance imaging (MRI) or computed tomography (CT) findings and then scoring the characteristic findings. Methods: A total of 18 patients were retrospectively assessed. To elucidate the characteristic findings, we investigated the following 10 items: age at diagnosis, sex, and site of occurrence; for MRI findings, the pattern of tumor expansion, T1-weighted images, T2-weighted images, septal structure, and cystic changes; and for CT findings, calcification or residual bone fragments and incomplete bone shells. Then, we developed a unique scoring system and investigated whether the two tumors could be differentiated by this scoring system. Results: Six items, including, age, site of occurrence, tumor expansion pattern, T2-weighted images, septal structure, and incomplete bone shells, were significantly different between giant cell tumor and chordoma patients. By using newly developed scoring system, the mean scores of 0.9 ± 0.6 (range 0–2) for giant cell tumor and 4.8 ± 1.5 (range 3–6) for chordoma patients were significantly different (P <0.001), thereby allowing the differential diagnosis by setting the cutoff value to three. Conclusions: We found that the six items were useful for differentially diagnosing giant cell tumor and chordoma. These results indicate that it may be possible to distinguish the two types of tumor by scoring these items.

Background: Adamantinoma arising in the femur is extremely rare. We report a case of an adamantinoma occurring in the right medial femoral condyle that was diagnosed 5 years after the primary surgery. Case presentation: A 74-year-old Asian woman first complained of right knee pain without any cause. Radiographs demonstrated a 4×4.5 cm osteolytic lesion in her medial femoral condyle. Magnetic resonance imaging revealed a lesion which showed low signal on both T1 and T2-weighted image, and enhanced signal with gadolinium contrast administration. She underwent a wide resection of the lesion and was reconstructed with a tumor endoprosthesis. On histological examination, the tumor showed clusters of spindle-shaped and squamoid epithelial cells among the fibrous stroma. Adamantinoma was considered, however, the diagnosis was inconclusive due to the unusual localization and her age. Moreover, it was difficult to exclude metastatic carcinoma. Five years later, she was diagnosed with an abnormal shadow occupying the upper lobe of her right lung in a routine physical examination. She subsequently underwent a resection of the lung mass which histologically showed proliferation of spindle-shaped and squamoid epithelial cells. The histological similarity of the lung tumor and the femoral tumor led to the diagnosis of adamantinoma arising in her right medial femoral condyle with metastasis to the upper lobe of her right lung. Conclusion: In this case report, we report the clinical, radiographic, and histological features of an adamantinoma arising in the distal femur with a review of the literature.

Skeletal muscle atrophy promotes muscle weakness, limiting activities of daily living. However, mechanisms underlying atrophy remain unclear. Here, we show that skeletal muscle immobilization elevates Smad2/3 protein but not mRNA levels in muscle, promoting atrophy. Furthermore, we demonstrate that myostatin, which negatively regulates muscle hypertrophy, is dispensable for denervation-induced muscle atrophy and Smad2/3 protein accumulation. Moreover, muscle-specific Smad2/3-deficient mice exhibited significant resistance to denervation-induced muscle atrophy. In addition, expression of the atrogenes Atrogin-1 and MuRF1, which underlie muscle atrophy, did not increase in muscles of Smad2/3-deficient mice following denervation. We also demonstrate that serum starvation promotes Smad2/3 protein accumulation in C2C12 myogenic cells, an in vitro muscle atrophy model, an effect inhibited by IGF1 treatment. In vivo, we observed IGF1 receptor deactivation in immobilized muscle, even in the presence of normal levels of circulating IGF1. Denervation-induced muscle atrophy was accompanied by reduced glucose intake and elevated levels of branched-chain amino acids, effects that were Smad2/3-dependent. Thus, muscle immobilization attenuates IGF1 signals at the receptor rather than the ligand level, leading to Smad2/3 protein accumulation, muscle atrophy, and accompanying metabolic changes.

BACKGROUND: Thresholds for spinal pelvic parameters in adult spinal deformity (ASD) were previously defined in North American patients and are commonly used to guide surgical planning. However, it is unclear whether these same threshold parameters can be more widely applied in other geographic regions and in other ethnicities. OBJECTIVE: To evaluate the variation in the radiographic disability thresholds between North American and Japanese ASD populations and to adjust sagittal modifier thresholds accordingly. METHODS: Retrospective case series of 717 patients with ASD who had baseline radiographs and Oswestry Disability Index (ODI) from North America (n 518) and Japan (n 199) were studied. Patients were compared at baseline for ODI, ODI offset from age- and ethnic-specific values (ODIni), and radiographic parameters. RESULTS: Significant differences in classification were observed: A greater proportion of Japanese patients had marked pelvic tilt deformity, whereas a greater proportion of US patients had marked SVA deformity; no difference in the pelvic incidence-lumbar lordosis mismatch sagittal modifier was observed. Health-related quality-of-life scores also differed, with a greater ODI raw value observed in the US patients but similar ODIni scores between cohorts. Stratifying ODIni scores by sagittal modifier grades revealed similar disability scores corresponding to the 0 to + thresholds for pelvic tilt, pelvic incidence-lumbar lordosis mismatch, and sagittal vertical axis across ethnicities. Finally, linear regression analysis demonstrated that compared with US patients, Japanese patients had a lower estimated ODI corresponding to established thresholds of radiographic deformity. CONCLUSION: Our findings demonstrate significant variability in health-related quality-of-life measures and radiographic parameters between North American and Japanese patients, supporting the need for population-adjusted sagittal modifiers to more accurately classify deformity.

Background: Preserving the hip joint to delay arthroplasty for patients with acetabular dysplasia-associated early-stage osteoarthritis has become more common, and several surgical procedures have demonstrated pain relief and improved hip joint function. Periacetabular osteotomy, one of the joint-preserving surgical procedures of the hip, provides favorable outcomes, although there are no reports of total hip arthroplasty being used to treat pseudoarthrosis of the periacetabular osteotomy segment. Therefore, we report a case of pseudoarthrosis in the osteotomy segment after periacetabular osteotomy. The patient was treated using modified total hip arthroplasty and achieved a favorable short-term outcome. Case presentation: A 62-year-old Japanese woman was diagnosed with bilateral acetabular dysplasia at the age of 50 years, and underwent right and left periacetabular osteotomy at the ages of 52 and 55 years, respectively. When she was 61-years old, she experienced repeated episodes of left coxalgia during walking, with increasing pain at rest, and subsequently visited our department. Plain radiography and computed tomography of her left hip joint confirmed pseudoarthrosis of the periacetabular osteotomy segment. In addition, narrowing of her left hip joint space was observed, which indicated advanced osteoarthritis of the hip. Therefore, she underwent left total hip arthroplasty when she was 62-years old. During the surgery, fibrous fusion of the periacetabular osteotomy segment was confirmed via fluoroscopy, although no abnormal mobility was observed. Thus, the osteotomy segment was fixed with one absorbable screw and two bone pegs (which were prepared using allogeneic bone), and the acetabular cup was fixed using cement. Her postoperative course was generally favorable and bone fusion of the periacetabular osteotomy segment was confirmed at 3 years and 6 months after surgery. Her modified Harris hip score was 43 before the surgery and had improved to 90 at the final follow-up. Conclusions: Modified total hip arthroplasty was successfully used to treat osteoarthritis of the hip and pseudoarthrosis of the periacetabular osteotomy segment. This procedure achieved pseudoarthrosis region bone fusion and a favorable postoperative outcome.

STUDY DESIGN.: Multicenter case–control study. OBJECTIVE.: To characterize the pathogenesis of idiopathic spinal epidural lipomatosis (SEL). SUMMARY OF BACKGROUND DATA.: SEL is often associated with the history of steroid use or endocrine disorders; however, the pathogenesis of idiopathic SEL remains poorly understood. METHODS.: Sixteen patients who underwent lumbar decompression surgery due to severe idiopathic SEL were included in the study (L group, 15 males and 1 female; mean age, 71.5 years). Fifteen patients without SEL, who underwent decompression surgery for lumbar canal stenosis, were selected as controls (C group, 14 males and 1 female; mean age, 70.3 years). The following parameters were analyzed in these two groups: body mass index (BMI), medical history, histology, the size of adipocytes in the epidural fat (EF) tissues, and the expression level of the transcripts for adiponectin, leptin, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8. RESULTS.: The mean BMI of the L group was significantly higher than that of the C group (29.1 vs. 25.2?kg/m, P?=?0.006), and there was a significant correlation between BMI and the width of EF in both groups. The average adipocyte size in the EF was significantly larger in the L group than in the C group (2846.8 vs. 1699.0?μm, P?=?0.017). Furthermore, the expression levels of the transcripts for TNF-α and IL-1β in the L group were significantly higher than those in the C group [2.59-fold increase (P?=?0.023) and 2.60-fold increase (P?=?0.015), respectively]. CONCLUSION.: Our data suggest that the pathogenesis of idiopathic SEL is associated with obesity. In addition, the increased expression of two major inflammatory cytokines in the EF in the L group may indicate that SEL is causally related to chronic inflammation.Level of Evidence: 3

Marfan syndrome (MFS) is an autosomal dominant genetic disease caused by abnormal formation of the extracellular matrix with an incidence of 1 in 3, 000 to 5, 000. Patients with Marfan syndrome experience poor quality of life caused by skeletal disorders such as scoliosis, and they are at high risk of sudden death from cardiovascular impairment. Suitable animal models of MFS are essential for conquering this intractable disease. In particular, studies employing pig models will likely provide valuable information that can be extrapolated to humans because of the physiological and anatomical similarities between the two species. Here we describe the generation of heterozygous fibrillin-1 (FBN1) mutant cloned pigs (+/Glu433AsnfsX98) using genome editing and somatic cell nuclear transfer technologies. The FBN1 mutant pigs exhibited phenotypes resembling those of humans with MFS, such as scoliosis, pectus excavatum, delayed mineralization of the epiphysis and disrupted structure of elastic fibres of the aortic medial tissue. These findings indicate the value of FBN1 mutant pigs as a model for understanding the pathogenesis of MFS and for developing treatments.

Various silver-coated implants have been developed to prevent implant-associated infections, and have shown dramatic effects in vitro. However, the in vivo results have been inconsistent. Recent in vitro studies showed that silver exerts antibacterial activity by mediating the generation of reactive oxygen species in the presence of oxygen. To maintain its antibacterial activity in vivo, the silver should remain in an ionic state and be stably bound to the implant surface. Here, we developed a novel bacteria-resistant hydroxyapatite film in which ionic silver is immobilized via inositol hexaphosphate chelation using a low-heat immersion process. This bacteria-resistant coating demonstrated significant antibacterial activity both in vitro and in vivo. In a murine bioluminescent osteomyelitis model, no bacteria were detectable 21 days after inoculation with S. aureus and placement of this implant. Serum interleukin-6 was elevated in the acute phase in this model, but it was significantly lower in the ionic-silver group than the control group on day 2. Serum C-reactive protein remained significantly higher in the control group than the ionic-silver group on day 14. Because this coating is produced by a low-heat immersion process, it can be applied to complex structures of various materials, to provide significant protection against implant-associated infections.

Objective: We examined the clinical features and functional outcomes of surgically repaired subcutaneous flexor tendon ruptures in patients with rheumatoid arthritis (RA). Methods: This retrospective study included 41 fingers of 24 RA patients who underwent surgical treatment for flexor tendon ruptures. Evaluations performed at the time of presentation following rupture were C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and disease activity score in 28 joints (DAS28)-ESR, as well as Larsen grading for carpal bone destruction. The ruptured tendon and postoperative active range of motion (ROM) of digits were also examined. Results: The mean CRP was 2.4 mg/dl, ESR was 52 mm/h, and the DAS28-ESR was 4.5. Carpal bone destruction according to Larsen grade IV–V was observed in 18/24 patients. Affected digits were most commonly the thumb (12) and the ring and little fingers (9 each). Tendon ruptures were most common in the carpal tunnel in zone IV. The mean postoperative finger ROM (flexion/extension) was 38°/2° for the interphalangeal (IP) joint of the thumb and 23°/−2° for the distal interphalangeal joint of the other four fingers. Conclusions: Patients with flexor tendon ruptures present with high disease activity and advanced bone destruction. It is important to reduce the risk of progressive bone destruction and subsequent tendon rupture via tight control of disease activity.

The purpose of this study was to elucidate the feasibility of microendoscopic discectomy (MED) for the treatment of lumbar disc herniation with a bony fragment due to apophyseal separation. Eighteen patients with low back pain and unilateral sciatic pain due to lumbar disc herniation with a bony fragment were treated by MED using the unilateral approach (15 males and three females; mean age, of 28.9 years; mean follow-up period, 21.1 months); 18 age-and sex-matched patients with lumbar disc herniation without a bony fragment treated by MED served as the control group. The clinical outcomes were evaluated using the Japanese Orthopedic Association Score for Low Back Pain (JOA scores; maximum score, 29 points). Evaluation of the results revealed that good surgical outcomes equivalent to those in the control group were obtained in the subjects of LDH with a bony fragment (JOA scores; 14.1±3.5 in the patient group vs. 15.4±2.6 in the control group before surgery; 26.3±1.8 in the patient group vs. 26.9±1.3 at follow-up after the surgery). Although the mean surgical time was significantly longer in the patient group, there were no intra- or postoperative complications in either group. We conclude that MED using the unilateral approach is a feasible minimally invasive surgical option for patients of lumbar disc herniation with an apophyseal bony fragment. © Georg Thieme Verlag KG Stuttgart.

STUDY DESIGN. Prospective clinical, radiologic study of adolescent idiopathic scoliosis (AIS). OBJECTIVE. We evaluated a Cobb angle in standing position, patient age, the level of the apex, and the number of involved vertebrae in patients with AIS to determine whether the corrective ability of traction or side-bending radiographs was superior. SUMMARY OF BACKGROUND DATA. Side-bending and traction radiographs are used to evaluate curve flexibility during corrective surgery for AIS despite notable differences in the flexibilities of identical curves. Thus, interpretation for the differences among these techniques should be investigated. METHODS. A total of 229 consecutive patients with AIS who were surgically treated were evaluated. Standing, supine side-bending, and traction radiographs were obtained before surgery. Curves were divided into main thoracic (MT) or thoracolumbar/lumbar (TL/L) curves, and proximal thoracic (PT) curves. We evaluated the Cobb angle in standing position, the level of the apex, the number of involved vertebrae, kyphosis angle of main thoracic curve, and patient age in patients with AIS to determine whether the corrective ability of traction or side-bending radiographs was superior. RESULTS. A total of 219 curves were observed in MT lesions. The traction flexibility rate (FR) was higher than the side-bending FR at angle of ≥60° (P = 0.02), in patients younger than 15 years (P = 0.02), in curves whose apex was located at T4-T8/T9(P = 0.01), in curves whose involved vertebrae were 6 or 7 (P = 0.02), and at kyphosis angle between 10° and 39° (P = 0.02). In 96 TL/L curves, side-bending FR was higher at angle of <60° (P < 0.01). In 163 PT curves, traction FR was higher at angles of ≥40° (P = 0.02). CONCLUSION. In addition to a Cobb angle, patient age, the level of the apex, and the number of involved vertebrae also influence the conditions under which the corrective ability of traction radiographs is superior to that of side-bending radiographs. © 2007 Lippincott Williams & Wilkins, Inc.

STUDY DESIGN: Retrospective study of patients with spinal arteriovenous fistula (AVF) who underwent surgical treatment. OBJECTIVE: To evaluate the validity of the intraoperative angiography (IA) for the surgical treatment of spinal AVF. SUMMARY OF BACKGROUND DATA: Owing to the development of interventional techniques, endovascular embolization has become the treatment of choice for AVF, but it is not applicable for every spinal AVF owing to anatomic complexity of the spinal cord vessels. To get effective occlusion of the AVF, IA has been routinely used in the management of cerebral vascular diseases, but report of its use for spinal AVF is rare. METHODS: Since 2004, 4 consecutive cases of spinal AVF (3 males and 1 female, 3 thoracic, and 1 thoracolumbar) were involved in this study. The mean age at the time of operation was 62.3 years (range from 48 to 76 y). Types of AVFs and surgical techniques were reviewed retrospectively and the outcomes were assessed using the Japanese Orthopedic Association scoring system. RESULTS: AVFs in 3 patients were diagnosed as the dural type and that in the remaining patient as the perimedullary type; all feeding arteries were derived from the ninth to 10th intercostal arteries. Preoperative angiography demonstrated that the feeding arteries in 2 patients with a dural AVF were the branches of Adamkiewicz artery and in another dural AVF case, the Adamkiewicz artery could not be determined, therefore, endovascular embolization was not feasible. Including a patient with perimedullary AVF, a microsurgical clipping combined with IA was selected as the treatment. Complete occlusion of the fistula was achieved in all cases, the mean preoperative Japanese Orthopedic Association score of 4.5 improved to 6 at the final follow-up, and no perioperative complications were observed during the follow-up period. CONCLUSIONS: The favorable clinical results in our spinal AVF cases confirmed that IA ensures safe and accurate occlusion of the fistula. This technique provides satisfactory surgical results for spinal AVFs. © 2007 Lippincott Williams & Wilkins, Inc.

The authors report the case of a 47-year-old woman who harbored a giant cell tumor at the T-5 level. She had undergone curettage of the tumor via a combined anterior and posterior approach at a regional hospital and was later referred to the authors' institution for treatment after the tumor recurred. On examination she exhibited progressive paraparesis and was nonambulatory due to cord compression caused by the tumor, which had invaded the spinal canal and extended to the right paravertebral muscles and right thoracic cavity. A spondylectomy was performed through a single posterior approach. The tumor, together with a portion of the dura mater, pleura, and muscles, was resected en bloc from T-4 to T-6. After resection, spinal reconstruction was performed by placement of an anterior titanium mesh cage as well as posterior pedicle screw and rod instrumentation. The patient's postoperative course was uneventful, and she exhibited substantial neurological recovery and became ambulatory. Two and a half years after surgery, the patient was tumor free. En bloc resection of a recurrent giant cell tumor was successfully achieved through a single posterior approach. This surgical technique can be an effective option for this pathological condition, which is difficult to manage using other conventional treatment options including repeated curettage and radiotherapy.