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The risk of great vessel injury is low in microendoscopic lumbar discectomy applied in a favorable visual field. However, it is important to be aware of the depth of the pituitary rongeur. In this article, the authors report the case of a 55-year-old woman with lumbar disc herniation who underwent microendoscopic discectomy and subsequently presented with an aneurysm and arteriovenous fistula located at the bifurcation of the right common iliac artery. The patient was treated with endoscopic placement of a stent graft and recovered uneventfully.

To prevent adjacent disc problems after spinal fusion, a pedicle screw with a mobile junction between the head and threaded shaft was newly developed. The threaded shaft of the screw has 10 degrees mobility in all directions, but its structure is to prevent abnormal translation and tilting. This screw was evaluated as follows: (1) endurance test: 10(6) times rotational stress was applied; (2) biological reactions: novel screws with a mobile head and conventional screws with a fixed head were inserted into the bilateral pedicles of the L3, L4, and L5 in two mini pigs with combination. Eight months after surgery, vertebral units with the screw rod constructs were collected. After CT scan, the soft and bony tissues around the screws were examined grossly and histologically. As a result, none of the screws broke during the endurance test stressing. The mean amount of abrasion wear was 0.0338 g. In the resected mini pig section, though zygapophyseal joints between fixed-head screws showed bony union, the amount of callus in the zygapophyseal joints connected with mobile-head screws was small, and joint space was confirmed by CT. No metalloses were noted around any of the screws. Novel screws were suggested to be highly durable and histologically safe.

Purpose: The type of osteoarthritis and the degree of severity which causes restriction of knee range of motion (ROM) is still largely unknown. The objective of this study was to analyse the location and the degree of cartilage degeneration that affect knee range of motion and the connection, if any, between femorotibial angle (FTA) and knee ROM restriction., Methods: Four hundreds and fifty-six knees in 230 subjects with knee osteoarthritis undergoing knee arthroplasty were included. Articular surface was divided into eight sections, and cartilage degeneration was evaluated macroscopically during the operation. Cartilage degeneration was classified into four grades based on the degree of exposure of subchondral bone. A Pearson correlation was conducted between FTA and knee flexion angle to determine whether high a degree of FTA caused knee flexion restriction. A logistic regression analysis was also conducted to detect the locations and levels of cartilage degeneration causing knee flexion restriction., Results: No correlation was found between FTA and flexion angle (r = -0.08). Flexion angle was not restricted with increasing FTA. Logistic regression analysis showed significant correlation between restricted knee ROM and levels of knee cartilage degeneration in the patella (odds ratio (OR) = 1.77; P = 0.01), the lateral femoral condyle (OR = 1.62; P = 0.03) and the posterior medial femoral condyle (OR = 1.80; P = 0.03)., Conclusion: For clinical relevance, soft tissue release and osteophyte resection around the patella, lateral femoral condyle and posterior medial femoral condyle might be indicated to obtain a higher degree of knee flexion angle.

We have previously reported that mature adipocyte-derived dedifferentiated fat (DFAT) cells have a high proliferative activity and the potential to differentiate into lineages of mesenchymal tissue similar to bone marrow mesenchymal stem cells (MSCs). In the present study, we examined the effects of autologous DFAT cell transplantation on bone regeneration in a rabbit bone defect model and an ovariectomy (OVX)-induced osteoporosis model. The formation of tissue-engineered bone (TEB) was observed when rabbit DFAT cells were loaded onto a β-tricalcium phosphate (TCP)/collagen sponge and cultured in an osteogenic differentiation medium for 3 weeks. Autologous implantation of DFAT cell-mediated TEB constructs promoted bone regeneration in a rabbit tibial defect model. Regenerated bone tissue induced by transplantation of DFAT cell-mediated TEB constructs was histologically well differentiated and exhibited higher bone strength in a three-point bending test compared to that induced by the β-TCP/collagen sponge alone. In OVX-induced osteoporosis model rabbits, DFAT cells were obtained with the osteogenic activity similar to cells from healthy rabbits. Intrabone marrow injection of autologous DFAT cells significantly increased the bone mineral density (BMD) at the injected site in the OVX rabbits. Transplanted DFAT cells remained mainly on the injection side of the bone marrow by at least 28 days after intrabone marrow injection and a part of them expressed osteocalcin. In conclusion, these results demonstrate that autologous implantation of DFAT cells contributed to bone regeneration in a rabbit bone defect model and an OVX-induced osteoporosis model. DFAT cells may be an attractive cell source for cell-based bone tissue engineering to treat nonunion fractures in all patients, including those with osteoporosis.

Justification Criteria for Vertebral Fractures 2012 version was made based on new clinical findings. Major differences in this version compared to the 1996 version are inclusion of the semiquantitative method (SQ), statements to improve considerations during radiographic analysis, and the need for more detailed evaluation by MRI.

Fondaparinux and enoxaparin are useful for preventing venous thromboembolism after total knee arthroplasty (TKA), but both drugs have associated complications. The purpose of this study was to clarify the risks associated with use of these drugs in Japanese patients who underwent TKA.A total of 575 patients (935 knees) underwent TKA and were retrospectively reviewed; 277 patients (454 knees) were treated with fondaparinux and 298 patients (481 knees) were treated with enoxaparin. The authors investigated the incidences of deep venous thrombosis of the lower limbs and pulmonary embolism to evaluate venous thromboembolism, knee enlargement compared with the preoperative size, incidence of subcutaneous knee hematoma, and other complications. No significant differences were observed between the 2 drugs regarding the incidences of deep venous thrombosis and pulmonary embolism. However, fondaparinux use resulted in knee enlargement (P<.0005) and subcutaneous hematoma of the knee (P=.035) significantly more often than enoxaparin use. Conversely, enoxaparin use significantly caused the elevation of alanine aminotransferase (one of the liver enzymes) at a higher rate than fondaparinux (30.1% vs 8.3%, respectively; P<.0001). However, the increased alanine aminotransferase levels were transient, and no patient exhibited symptoms of abnormal liver function, such as jaundice or cutaneous pruritus.Fondaparinux and enoxaparin were both effective in preventing venous thromboembolism in Japanese patients undergoing elective TKA. However, both drugs had some adverse effects. It is important to be aware of these potential risks when prescribing these drugs., (Copyright 2013, SLACK Incorporated.)

Objective: Substantial evidence suggests that human synovial mast cells (MCs) are involved in the pathogenesis of rheumatoid arthritis (RA). A plausible pathway for the activation of synovial MCs is through IgG receptors, given the prevalence of circulating IgG isotype autoantibodies and synovial immune complexes in patients with RA. However, IgG receptor expression on human synovial MCs remains uncharacterized. The aim of this study was to identify which IgG receptor(s) on synovial MCs are responsible for MC activation in immune complexes., Methods: Synovial tissue specimens were obtained from patients with RA or patients with osteoarthritis (OA) who were undergoing joint replacement surgery, and synovial MCs were enzymatically dispersed. Cultured synovium-derived MCs were generated by culturing synovial cells with stem cell factor, and receptor expression was analyzed using fluorescence-activated cell sorting. Mediators released from MCs were measured using enzyme immunoassays or enzyme-linked immunosorbent assays., Results: Primary synovial MCs and cultured synovium-derived MCs obtained from both patients with RA and patients with OA expressed Fcε receptor I (FcεRI), FcγRI, and FcγRII but not FcγRIII. Cultured synovium-derived MCs induced degranulation and the production of prostaglandin D2 and tumor necrosis factor α (TNFα) through FcγRI. The aggregation of FcγRII caused histamine release from cultured MCs but not from primary MCs. Histamine release induced by aggregated IgG was significantly inhibited by neutralizing anti-FcγRI monoclonal antibody and anti-FcγRII monoclonal antibody., Conclusion: With regard to the FcR expression profile, synovial MCs from patients with RA and patients with OA were similar. FcγRI was responsible for producing abundant TNFα from synovial MCs in response to aggregated IgG. Immune complexes may activate synovial MCs through FcγRI and FcγRII., (Copyright © 2013 by the American College of Rheumatology.)

Background and Aims: Our hospital has used LLLT in the treatment of athletes since 1990. We had a good result about LLLT for sports injuries. However, few articles have attempted to evaluate the efficacy of LLLT for sports injuries. The aims of this study was to evaluate the efficacy of LLLT for sports injuries. Materials (Subjects) and Methods: Forty one patients underwent LLLT in our hospital. These patients included 22 men and 19 women with an average age of 38.9 years old. Patients were irradiated by diode laser at points of pain and/or acupuncture points. Patients underwent LLLT a maximum treatment of 10 times (mean 4.1 times). We evaluated the efficacy of LLLT using a Pain relief score (PRS). A score of 2 to 5 after treatment was regarded as very good, 6 to 8 as good, and 9 to 10 as poor. A PRS score of less than 5 was regarded as effective., Results: The rate of effectiveness (PRS of 5 or less) after LLLT was 65.9% (27/41 patients)., Discussion: In this study, the resulting rate of effectiveness was 65.9% for all sports injuries. However, we have a high rate of effectiveness for Jumper's knee, tennis elbow and Achilles tendinitis and cases that were irradiated laser by a physician., Conclusions: LLLT is an effective treatment for sports injuries, particularly jumper's knee, tennis elbow and Achilles tendinitis.

Background: Substantial evidence suggests that human synovial mast cells (MCs) are involved in the pathogenesis of rheumatoid arthritis (RA). Interleukin (IL)-33 is believed to play an important role in the pathogenesis of RA. We recently reported that FcγRI is responsible for producing abundant tumor necrosis factor alpha (TNF-α) from cultured synovium-derived MCs (SyMCs) in response to aggregated immunoglobulin G (IgG). However, whether or not IL-33 affects immune complex (IC)-induced synovial MC activation remains unknown. This study sought to evaluate the effect of IL-33 on IC-induced synovial MC activation., Methods: Cultured SyMCs were generated by culturing synovial cells with stem cell factor. ST2 expression was analyzed using FACS and immunohistochemical techniques. Mediators released from the MCs were measured using EIAs or ELISAs., Results: SyMCs obtained from patients with RA or osteoarthritis (OA) expressed ST2 on their surfaces. We confirmed the expression of ST2 in MCs using immunofluorescence staining in joint tissue obtained from RA patients. IC-triggered histamine release was not enhanced by IL-33. However, IL-33 synergistically enhanced IC-induced IL-8 and TNF-α production in SyMCs., Conclusions: ICs and IL-33 may exacerbate inflammation associated with RA by abundantly producing TNF-α and IL-8 from SyMCs., (Copyright © 2013 S. Karger AG, Basel.)

BACKGROUND: Among 40 patients with primary malignant tumors of the knee joint who underwent reconstruction of the affected limb with tumor prosthesis, revision was required in 7 due to stem breakage or loosening. SUBJECTS AND METHODS: In the 7 cases undergoing revision, conditions and background factors at the time of breakage, the breakage site, time of revision, models of previous and new prostheses, stem diameters before and after revision, details of the revision (blood loss, operative time), and the presence or absence of adjuvant therapy were determined. RESULTS: The replacement site was the distal femur in 5 and proximal tibia in 2. Revision was performed 6 years and 2 months after the previous prosthesis placement on average. The broken prosthesis model was KMFTR in 4 and HMRS and the physio-hinge type in one each. Revision due to loosening was performed in a case requiring replacement with Growing Kotz prosthesis. The model was switched to HMRS in 3, and the stem diameter was changed to 12 mm in 3 KMFTR breakage cases. The mean stem diameters were 11.2 and 10.2 mm in the non-revision and revision groups. The respective resection rates were 36 and 45%. The mean functional evaluation was 70.1% before and 76.2% after revision. CONCLUSION: To reduce the risk of tumor prosthesis breakage, the amount of bone resection should be limited to 30% or less in the affected bone, the stem diameter should be at least 12 mm, and the stem shape should be fitted to the anatomical shape of the femur.

With the advances in early diagnosis and treatment of cancer, prognosis of cancer patients has been improved significantly. Therefore improvement of QOL for cancer patients has become an important issue. Prevention of skeletal related event is one of the major factors to improve QOL in patients with bone metastasis. Since the clinical introduction of zoledronic acid, management of bone lesions has been improved and decreased SRE significantly. The specialists from four disease area which is multiple myeloma, urological cancer, lung cancer and breast cancer have discussed the benefits (and risks?) of the zoledronic acid with the current status of bone management in each cancer.

Histological and molecular changes were examined to investigate the effects of long-term administration of glucosamine (GlcN) and chondroitin sulfate (CS) in a model of spontaneous osteoarthritis (OA) in Hartley guinea pigs. Three groups of female 3-week-old Hartley guinea pigs received GlcN, CS, and neither agent, respectively. Five animals in each group were sacrificed at 8, 12, and 18 months of age. At 8 months of age, Hartley guinea pigs had severe degeneration of knee joint cartilage, chondrocyte apoptosis, marked reduction of tissue total RNA, decreases of aggrecan and collagen type 2 mRNAs, and increases in MMP-3 and MMP-8 mRNAs. Long-term administration of GlcN and CS reduced cartilage degeneration at 8 months of age. The marked loss of total RNA and the increase in MMP-3 mRNA were also inhibited by GlcN and CS. Thus, long-term oral administration of GlcN or CS inhibits OA progression, maintains total RNA and down-regulates MMP-3 mRNA in a spontaneous OA model in Hartley guinea pigs., (Copyright © 2011 Orthopaedic Research Society.)

Incisional biopsy and intramedullary pinning were performed for pathological fracture associated with a malignant bone tumor of the proximal humerus. Osteosarcoma, for which preoperative chemotherapy had been performed, was confirmed by postoperative pathological examination. To achieve wide resection and acquire a safe resected margin, total humerus replacement was performed, and the whole humerus was reconstructed using the Howmedica Modular Reconstruction system. The patient resumed normal activities, although mild contracture of the elbow joint remains 8 years after surgery.

We report a 38-year old man with a giant-cell tumor in a rare site, the patella. Primary patellar neoplasms are highly unusual. According to a survey by the Bone and Soft Tissue Tumor Committee of the Japanese Orthopaedic Association, of more than 2,126 giant-cell tumors of bone reported since 1972, only 22 were primary patellar neoplasms. We present a case of this rare entity along with its clinical and radiographic features. The first clinical symptom was anterior knee pain. Though anterior knee pain has numerous and varied causes, it is necessary to consider patellar bone tumors in the differential diagnosis.

Purpose: Total knee arthroplasty (TKA) has been proven to be the most effective treatment for patients with severe joint disease. Although infection is not a frequent complication, it is certainly one of the most dreaded. The purpose of this study was to identify factors associated with infection after TKA., Methods: Between 1995 and 2006, 2,022 primary TKAs in 1,146 patients were evaluated. Flexible Nichidai Knee (FNK) was used as a prothesis in all subjects. Twenty-four patient-specific data items were collected via chart review for each patient. Revision arthroplasty procedures and infected knees were excluded. The medical records were reviewed to extract the following information: age, gender, body mass index (BMI), preoperative C-reactive protein (CRP), preoperative erythrocyte sedimentation rate (ESR), preoperative total protein (TP), duration of surgery, operative blood loss, total blood loss, duration of surgical drain, duration of antibiotic prophylaxis, primary diagnoses, smoking, diabetes mellitus, steroid or disease modifying anti-rheumatic drugs (DMARDs) therapy, previous operation around the knee joint, previous arthroscopic surgery, previous non-arthroscopic surgery, previous high tibial osteotomy (HTO) or open reduction internal fixation (ORIF), remnants of previous internal fixation material, bone graft, patella replacement, and bone cement., Results: The median age of the patients at the time of primary TKA was 72 (range, 26-91) years. The median follow-up period after primary TKA was 42 (range, 6-145) months. During the study period, 17 infected knee arthroplasties in 17 patients were identified. Previous history of ORIF, male gender, remnants of previous internal fixation material, and BMI showed significant correlation with postoperative infection., Conclusion: This study identified previous history of fracture and remnants of internal fixation as major risk factors of infection after TKA. For clinical relevance, surgeons should be aware of potential infection when performing TKA in patients with these risk factors and patients should be informed of the potential risks.

Background: Knee size and body size differ in Asians compared with Caucasians. Nevertheless, many total knee arthroplasty (TKA) prostheses used worldwide are made for Western Caucasian subjects. As a result, an Asian's knee might not fit these prostheses. We studied the Flexible Nichidai Knee (FNK) system, a new model of TKA for Asian patients. The purpose of this report is to investigate the outcomes of this prosthesis retrospectively., Methods: We investigated 1055 primary TKAs in 595 patients who underwent FNK for osteoarthritis (OA) in Japan and were followed for > 5 years. The knee score and function score were used for clinical evaluation. We examined the range of motion (ROM) preoperatively and at final follow-up and radiographic assessments. In addition, postoperative complications were investigated. A survivorship analysis was also conducted using two endpoints: revision for any reason and aseptic failure., Results: 890 knees in 502 patients were available for study (follow-up rate of 96.0%). The mean follow-up term was 8.3 years (range, 5.0-14.1 years). The knee and function score significantly improved from 41.3 to 90.3 and from 39.1 to 76.2 points, respectively (p < 0.001). The mean ROM in FNK posterior cruciate retaining (CR) type and FNK posterior-stabilized (PS) type ameliorated significantly from 107.8° and 95.6° to 110.7° and 110.4°, respectively (p < 0.01). Ten knees underwent revision surgery (infection in 3 cases, instability in 2, loosening in 2, and non-union of femoral supracondylar fracture, severe pain, and recurrent hemarthrosis in 1 each). The survivorship rate was 99.4% (95% CI, 99.0-99.8) at 5 years (n = 952 patients at risk) and 96.2% (95% CI, 91.9-100) at 12.5 years (n = 49 patients at risk)., Conclusion: The FNK prosthesis for Asians achieved excellent mid- to long-term survivorship and clinical results.

Background/purpose: In limb reconstruction following resection of malignant bone tumors in children, extendable prostheses are considered to be useful since future leg length correction can be controlled. We evaluated the usefulness of extendable prostheses in 11 such cases., Methods: The study included 11 children aged 7-16 years (mean 11 years) who underwent limb reconstruction using an extendable prosthesis between 1994 and 2008. The follow-up period varied from 1 to 16 years (mean 6 years and 2 months). Nine patients had osteosarcoma, one had a primitive neuroectodermal tumor (PNET) and one had Ewing's sarcoma. The tumor was located in the distal femur, (n = 6), proximal femur (n = 1), or proximal tibia (n = 4). Functional scores, X-ray images, the number of lengthening procedures, total length gain, complications, and leg length discrepancy were recorded for each patient., Results: The functional scores range from 52% to 96% (mean 84%). X-Ray evaluation revealed fair and poor bone remodeling in three patients each. The mean number of elongation procedures was 2.8 and the mean total length gain was 49.7 mm. The final leg length discrepancy was 29.2 mm., Conclusion: Extendable bone prostheses are useful for reconstruction. According to our experience, this method is indicated in children of at least 10 years of age for whom a future leg-length discrepancy of up to 4 cm is expected and who have a lesion located in the distal femur where the prosthesis can be adequately covered by soft tissue., (Copyright © 2011. Published by Elsevier B.V.)

This article reports a case of bilateral fatigue fracture of the femoral components in a cruciate-retaining uncemented total knee arthroplasty (TKA). A 75-year-old woman (height, 158 cm; weight, 72 kg; body mass index, 29.2) had undergone one-stage bilateral TKA for osteoarthritis 11 years previously at the author's institution. Surgery was performed using an uncemented Flexible Nichidai Knee. Equal tension of the collateral ligaments and normal mechanical axis were achieved during the primary procedure. The patient was an ardent lover of the game of badminton and had higher activity levels with daily playing. At 8 years postoperatively, she started complaining of mild pain in both knees. The pain gradually increased, and at 11 years postoperatively, she had difficulty walking. Anteroposterior radiographs showed narrowing of the medial joint space, indicating wear of the polyethylene insert. Lateral radiographs showed signs of broken implants in both knees. There were no signs of gross implant loosening or osteolysis. One-stage revision surgery was performed, and the knees were converted to cemented posterior-stabilized TKAs. At revision, the bilateral femoral components were found to be fractured at the junction between the trochlear flange and the medial condyle, anteriorly to the medial peg. The polyethylene insert showed mild wear at the medial middle portion. In the majority of case reports, stress fractures of the femoral component have predominantly affected the medial condyle, following uncemented implantation of fixed-bearing knees. In this case, failure of bone ingrowth in uncemented components, higher body mass index, and a higher athletic activity led to fatigue fracture of the femoral components., (Copyright 2011, SLACK Incorporated.)

Background: Intercondylar notch narrowing is a risk factor for anterior cruciate ligament (ACL) injuries, but it is unclear whether a narrow intercondylar notch correlates with bilateral ACL injuries., Purpose: To determine whether a narrow intercondylar notch is associated with bilateral ACL knee injuries in athletes, using magnetic resonance imaging (MRI) and radiography to investigate the notch size., Study Design: A retrospective case-control study., Methods: This was a comparative cohort study on 50 subjects of which 25 patients with sport trauma-associated bilateral ACL injuries, 30 with unilateral ACL injuries, and 20 healthy subjects. The notch width index (NWI) was measured as the ratio of the width of the intercondylar notch to the femoral condylar width on radiography and the MRI slice containing the region near the ACL attachment site on the femoral side (NWI-A) and on the following posterior slice (NWI-P)., Results: The mean NWI values on radiography were 0.257 (SD 0.040), 0.332 (SD 0.036), and 0.341 (SD 0.027) in the bilateral, unilateral, and control groups, respectively, with significant differences between the bilateral and unilateral groups and the bilateral and healthy groups. On MRI, the mean NWI-A values were 0.236 (SD 0.025), 0.243 (SD 0.048), and 0.266 (SD 0.030), respectively, with a significant difference between the bilateral and healthy groups. The mean NWI-P values were 0.239 (SD 0.021), 0.258 (SD 0.038), and 0.273 (SD 0.033), respectively, with significant differences between the bilateral and unilateral groups and the unilateral and healthy groups. A cutoff value of 0.25 for NWI-P gave an odds ratio of 22.667 for the risk of developing bilateral ACL knee injuries., Conclusions: The intercondylar notch was significantly narrower in subjects with bilateral ACL injuries than in healthy subjects. NWI measurement using coronal MRI is useful for judging intercondylar notch narrowing. The risk for ACL injuries is very high when NWI is ≤0.25. Preventive measures for the unaffected knee are required for patients with a narrow intercondylar notch.

Objective: In this study, we examined the therapeutic effect of photodynamic therapy (PDT) using the photosensitizer Na-Pheophorbide a (Na-Phde a) on osteomyelitis models in rats., Background: Osteomyelitis is one of the most serious infectious problems in the orthopedic field. Recently, as a new clinical approach against septic arthritis, an experimental in vivo and in vitro model for the inactivation of methicillin-resistant-Staphylococcus aureus by PDT using Na-Phde a has been developed., Methods: Methicillin-sensitive Staphylococcus aureus (MSSA) was injected into the tibia of the rats to create osteomyelitis models (n = 10, 10 legs). A total of 560 μmol/l of Na-Phde a solution was injected into five of these tibial osteomyelitis models (five legs) 48 h after the initial MSSA infection. Sixty minutes after the Na-Phde a injection, a semiconductor laser (125 mW, 670 nm) was used to irradiate the models for 10 min with a total energy of 93.8 J/mm(2). As a control group, five rats (five legs) were treated with a phosphate buffered saline injection at 48 h after MSSA infection. Weight and leg perimeter changes were plotted. Bacterial growth, histological examination and radiological examination were evaluated at 14 days after initial treatment., Results: PDT with Na-Phde a significantly prevented leg swelling. In the PDT group, bone destruction owing to osteomyelitis was inhibited not only histologically but also radiographically., Conclusions: The results in these experiments show that PDT using Na-Phde a improved osteomyelitis in rats. This suggests that PDT using Na- Phde a can be a useful treatment for osteomyelitis.

The goal of this study was to evaluate the long-term survivorship of primary cementless total hip arthroplasty (THA) using Harris-Galante porous I acetabular and Harris-Galante porous femoral components. From July 1985 to December 1991, we performed primary cementless THA on 76 hips (70 patients). Twenty-nine patients (31 hips) died due to causes unrelated to the THA, and 6 patients (7 hips) were lost to follow-up. Of 76 hips (70 patients) studied, 38 hips (35 patients) were available for follow-up at a mean 22.5 years (range, 19-25 years) postoperatively. Mean patient age at index procedure was 51.2 years (range, 42-65 years). Average Harris Hip Score was 40.5 points preoperatively and 85.8 points at final follow-up. No patient had an early or late postoperative deep infection. Radiographically, the acetabular component fixation was stable in all 38 hips. The femoral component was bone-ingrown in 26 hips, stable-fibrous in 10, and unstable in 2. One unstable hip required revision of the femoral component. Dissociation of the polyethylene liner occurred in 3 hips without fractures of the metal locking tines and required revision of the polyethylene liner and the articular head. A total of 4 hips had documented revision, and 1 femoral component failed radiographically. The survival rate with the endpoint defined as revision surgery and radiographic loosening was 86.8% at 22.5 years of follow-up. Mean polyethylene wear was 0.085 mm/year (range, 0.031-0.15 mm). This study found that the Harris-Galante porous I acetabular and Harris-Galante porous femoral components produce excellent long-term results., (Copyright 2011, SLACK Incorporated.)

We evaluated the fate of bulk femoral head autograft in cementless total hip arthroplasty (THA) for developmental hip dysplasia. Of 87 hips (80 patients) studied, 37 hips (32 patients) were available for follow-up at a mean of 18.5 years (range, 15-24 years) postoperatively. The mean age of these 32 patients at the index procedure was 53.8 years (range, 40-65 years). The initial diagnosis was osteoarthritis in all 32 patients. The degree of acetabular dysplasia according to Crowe classification was type I in 18 hips (48.6%), type II in 14 (37.8%), type III in 5 (13.5%). The mean percentage of horizontal coverage of the acetabular components with graft bone was 34% (range, 25%-45%). Trabecular bridging across the graft-host interface was seen at a mean of 4 months (range, 2-6 months) postoperatively. Trabecular reorientation of the grafted bone was seen in all hips at a mean of 27 months (range, 12-36 months) postoperatively. There was no evidence of collapse and bony resorption of the grafted bone in the weight-bearing portion. Acetabular component fixation was stable in all hips at final follow-up. Of the 37 hips (32 patients), 2 acetabular components required revision: 1 for a late postoperative deep infection and 1 for dissociation of the polyethylene liner. The survival rate was 94.5% (95% confidence interval, 91.3-96.5) for the acetabular component at 18.5 years of follow-up. This study found that bulk femoral head autograft in cementless THA for developmental hip dysplasia produces excellent long-term results., (Copyright 2011, SLACK Incorporated.)

This article presents a case of femoral corrective osteotomy for malunited supracondylar femoral fracture after total knee arthroplasty (TKA) in a patient with rheumatoid arthritis. The patient underwent 1-stage bilateral TKA and 2-stage bilateral total hip arthroplasty 17 years prior at our institution. Her fall 10 years before led to a supracondylar femoral fracture that was treated nonoperatively for 3 months and led to malunion. Complaints of mild right knee pain and remarkable varus deformity were observed. On examination, the right knee was not swollen and tender. Range of motion (ROM) of the right knee was 0° to 130°. The patient needed crutches to ambulate. Knee score and function scores, according to the Knee Society clinical rating system, were 65 and 25 points, respectively. Radiographs after malunion showed remarkable varus knee and the femorotibial angle was 197°. At the time of surgery, the components were stable and bone union was completed. Valgus corrective osteotomy of the femur was performed using a retrograde intramedullary nail, with satisfactory results at 10-year follow-up. The patient is able to walk without a cane and has 0° to 130° ROM. Knee and function scores were 88 and 80 points, respectively. Radiographs showed complete bone union and the femorotibial angle was 179° with no loosening of the prostheses. Femoral corrective osteotomy is recommended for malunited supracondylar femoral fracture after TKA., (Copyright 2010, SLACK Incorporated.)

The objective of this study was to investigate the accurate AM and PL tunnel positions in an anatomical double-bundle ACL reconstruction using human cadaver knees with an intact ACL. Fifteen fresh-frozen non-paired adult human knees with a median age of 60 were used. AM and PL bundles were identified by the difference in tension patterns. First, the center of femoral PL and AM bundles were marked with a K-wire and cut from the femoral insertion site. Next, each bundle was divided at the tibial side, and the center of each AM and PL tibial insertion was again marked with a K-wire. Tunnel placement was evaluated using a C-arm radiographic device. For the femoral side assessment, Bernard and Hertel's technique was used. For the tibial side assessment, Staubli's technique was used. After radiographic evaluations, all tibias' soft tissues were removed with a 10% NaOH solution, and tunnel placements were evaluated. In the radiographic evaluation, the center of the femoral AM tunnel was placed at 15% in a shallow-deep direction and at 26% in a high-low direction. The center of the PL bundle was found at 32% in a shallow-deep direction and 52% in a high-low direction. On the tibial side, the center of the AM tunnel was placed at 31% from the anterior edge of the tibia, and the PL tunnel at 50%. The ACL tibial footprint was placed close to the center of the tibia and was oriented sagittally. AM and PL tunnels can be placed in the ACL insertions without any coalition. The native ACL insertion site has morphological variety in both the femoral and tibial sides. This study showed, anatomically and radiologically, the AM and PL tunnel positions in an anatomical ACL reconstruction. We believe that this study will contribute to an accurate tunnel placement during ACL reconstruction surgery and provide reference data for postoperative radiographic evaluation.

We compared the results of 1-stage uncemented bilateral total hip arthroplasty (THA) performed in 49 patients (98 hips) with those of 2-stage uncemented bilateral THA performed during the same hospital stay in 40 patients (80 hips). There was no significant difference in mean Harris Hip Score preoperatively and at final follow-up between the 2 groups. Radiographic evaluation of patients in the 1-stage group revealed the acetabular component was stable in 95 hips and possibly unstable in 3. The femoral component was bone-ingrown in 91 hips and stable fibrous in 7. In the 2-stage group, the acetabular component was stable in 77 hips and possibly unstable in 3. The femoral component was bone-ingrown in 71 hips and stable fibrous in 9. In both groups, no patients exhibited clear signs of loosening, migration or osteolysis.In the 1-stage group, postoperative dislocation occurred in 2 hips and 1 patient had developed deep venous thrombosis and pulmonary embolism. In the 2-stage group, no complications were observed. The incidence of complications was not significantly different between the 2 groups.There was no significant difference in the total blood loss and mean hemoglobin level preoperatively and at discharge between the 2 groups. However, in the 1-stage group, operative time, intraoperative blood loss, procedure cost, and hospital stay were significantly reduced compared with the 2-stage group. Therefore, 1-stage bilateral THA is a safe and effective option for patients with significant arthritic disease of both hips., (Copyright 2010, SLACK Incorporated.)

We assessed 90 total hip arthroplasties (THAs) performed with the Metasul metal-on-metal hip system (Zimmer, Warsaw, Indiana); the patients were monitored for >10 years. The average Harris Hip Score of the patients was 40.5 points preoperatively and 85.8 points at final follow-up. No adverse reactions to the metal debris were observed in patients presenting with symptoms or phenomena such as unexplained pain, joint effusion, bursitis, or pseudotumor. Radiographically, the acetabular component fixation was stable in 86 hips, possibly unstable in 3 hips, and unstable in 1 hip. The unstable hip required revision of the acetabular component. The femoral component was bone-ingrown in 81 hips and stable-fibrous in 9 hips. Distal femoral cortical hypertrophy was seen in 34.4% of hips.Postoperatively, 6 hips dislocated, of which 2 developed recurrent dislocation and required revision of the acetabular component. Dissociation of the polyethylene liner occurred in 2 hips 6 and 12 years postoperatively, respectively, and required revision of the polyethylene liner and the articular head. The survival rate with the endpoint defined as revision surgery and radiologic loosening was 94.4% at mean follow-up (12.3 years). This study found that the Metasul metal-on-metal THA produces excellent long-term results., (Copyright 2010, SLACK Incorporated.)

Background: Rehabilitation is one of the most critical points after anterior cruciate ligament (ACL) reconstruction. However, the recent trend of low-cost, short-term hospitalization makes sufficient rehabilitation after ACL reconstruction difficult., Level of Evidence Iii: 34 patients who underwent non-anatomical single bundle ACL reconstruction using a hamstring auto graft were evaluated. Twenty patients (12 males and 8 females) were transferred to a special rehabilitation hospital (RH hospital group) after operation and concentrated rehabilitation was performed up to 4 h per day. Fourteen (9 males and 5 females) patients performed clinic-based rehabilitation at a university hospital three times per week (clinic group). Strength of quadriceps and knee flexion muscles was assessed at 60 degrees /s using a Cybex II dynamometer (Lumex, Ronkonkoma, NY, USA) at 3, 6 and 9 months after ACL reconstruction. Anterior tibial translation (ATT) and pivot shift test were also evaluated., Results: No significant difference in muscle recovery in the lower extremity was observed at any time point after ACL reconstruction between the clinic group and the RH hospital group. However, 3 months after operation, the average muscle strength of the RH hospital group tended to be higher than that of the clinic group. There was no significant difference in ATT or pivot shift (each group included 4 positive pivot shift subjects) in the patients who were tested between the clinic group and the RH hospital group., Conclusion: Concentrated rehabilitation at a rehabilitation hospital after ACL reconstruction has the potential to improve muscle strength in the lower extremities more dramatically in the early stages of post operation. However, the initial benefits of intensive physiotherapy disappear after 6 months.

Background: In the reconstruction of the affected limb in pediatric malignant bone tumors, since the loss of joint function affects limb-length discrepancy expected in the future, reconstruction methods that not only maximally preserve the joint function but also maintain good limb function are necessary. We analysis limb function of reconstruction methods by tumor location following resection of pediatric malignant bone tumors., Patients and Methods: We classified the tumors according to their location into 3 types by preoperative MRI, and evaluated reconstruction methods after wide resection, paying attention to whether the joint function could be preserved. The mean age of the patients was 10.6 years, Osteosarcoma was observed in 26 patients, Ewing's sarcoma in 3, and PNET(primitive neuroectodermal tumor) and chondrosarcoma (grade 1) in 1 each., Results: Type I were those located in the diaphysis, and reconstruction was performed using a vascularized fibular graft(vascularized fibular graft). Type 2 were those located in contact with the epiphyseal line or within 1 cm from this line, and VFG was performed in 1, and distraction osteogenesis in 1. Type III were those extending from the diaphysis to the epiphysis beyond the epiphyseal line, and a Growing Kotz was mainly used in 10 patients. The mean functional assessment score was the highest for Type I (96%: n = 4) according to the type and for VFG (99%) according to the reconstruction method., Conclusion: The final functional results were the most satisfactory for Types I and II according to tumor location. Biological reconstruction such as VFG and distraction osteogenesis without a prosthesis are so high score in the MSTS rating system. Therefore, considering the function of the affected limb, a limb reconstruction method allowing the maximal preservation of joint function should be selected after careful evaluation of the effects of chemotherapy and the location of the tumor.

Vertebroplasty was performed using hydroxyapatite blocks to examine the course of compressive strength and histological features in a dog model. The vertebral fracture model was prepared by punching a hole in the center of the vertebra and at 4 sites around the vertebra (5 holes in total) from the front side of the vertebra using an air drill and hollowing the holes. Measurements were made on healthy vertebrae, vertebrae from the vertebral fracture model, vertebrae removed from animals immediately after vertebroplasty, vertebrae collected 1 and 2 months after vertebroplasty, and vertebrae untreated for 1 month after vertebral fracture. Histological examinations were also performed 1 and 2 weeks and 1 and 2 months after vertebroplasty with hydroxyapatite blocks. The strength of vertebrae in the fracture model immediately after vertebroplasty was significantly higher than that in the untreated fracture, and the strength of vertebrae 1 month after the procedure was equivalent to that of healthy vertebrae. Histologically, new bone formation was found around hydroxyapatite blocks 2 weeks after the procedure, and strong crosslinking between neighboring hydroxyapatite blocks was found after 1 month.These results suggest that hydroxyapatite blocks may be effective as filling material for vertebral fracture from both biomechanical and histological perspectives., (Copyright 2010, SLACK Incorporated.)

Many epidemiological surveys have identified smoking as a risk factor for osteoporosis, but it is unclear whether smoking has a direct effect on bone metabolism and if such an effect could cause osteoporosis. Therefore, we examined whether smoking causes osteoporosis based on the impact of smoke exposure on the bones of rats. A rat model of passive cigarette smoking was prepared by breeding rats in a cigarette-smoking box for 4 or 8 weeks. Histological changes, micro-computed tomographic (CT) analysis, mechanical bone strength, and bone mineral density of the femur and lumbar vertebrae were examined in these rats and in control rats that were not exposed to smoke. Lower mechanical bone strength was observed in smoke-exposed rats, but these differences were not significant. Significantly lower bone mineral density was found in the femur (P<.01) and lumbar bones (P<.001) of 8-week smoke-exposed rats compared to controls. In a micro-CT scan of lumbar vertebrae, the bone volume, trabecular thickness, trabecular number, and trabecular separation differed significantly between smoke-exposed rats and controls. Histologically, the osteocytes in the smoke-exposed rats were small (approximately 25% of the size in controls), and decreased numbers of marrow cells and osteoblasts (P<.01), as well as a black carbon dust-like substance, were found in the bone of smoke-exposed rats. These results indicate that smoking significantly decreases bone mineral density, which causes osteoporosis, and the organizational changes in the bone suggest a direct effect of smoking on bone structure. Fewer marrow cells were present in the smoke-exposed rats, and a black carbon dust-like substance was observed., (Copyright 2010, SLACK Incorporated.)

Background: As for being cautious with tumor prostheses, revision of uncemented tumor prostheses in particular, it is necessary to remove cortical bone from the stem circumference with a chisel when the stem is extracted. This assures that bone in-growth will occur within the stem in itself. As a result, re-substitution of mass autogenous bone graft round a new stem is subsequently necessary. When rivision of uncemented tumor prosthesis of distal femur was performed, we evade fibula transplant by transplanting interconnected porous hydroxyapatite ceramic (IP-CA: Neobone) with a self bone, and reports its experience with the case that acquired enough strength., Case Report: In this report, we present the case of a 27-year-old female with stem breakage of tumor prosthesis and do revision surgery for prosthetic failure. In the case of revision surgery, autologous bone and Neobone were mixed, and this was transplanted to stem circumference. The Radiological Evaluation System of the ISOLS showed excellent results for all items. She can walk without using a cane or orthosis, and the score of the MSTS is 80%., Conclusion: When revision of uncemented tumor prostheses of the distal femur was performed, we avoided fibula graft by using Neobone with the patient's own bone tissue. Our experience with this case may indicate that adequate strength is achieved.

Posterior lumbar interbody fusion is considered to be an excellent fusion procedure to stabilize anterior support, correct alignment in the sagittal and coronal plane, and achieve foraminal decompression by lifting the disk height. The metal interbody cage in posterior lumbar interbody fusion is thought to be useful to prevent collapse of the graft bone and to correct and maintain disk height; however, some studies have noted a gradual decrease of disk height due to cage subsidence. Therefore, to investigate the significance of cage subsidence, 86 disk levels radiographically confirmed to have good union in 66 patients with posterior lumbar interbody fusion combined with pedicle screw fixation and a single metal cage for degenerative lumbar disease were retrospectively evaluated. The follow-up period ranged from 3 years to 10 years 3 months, with a mean of 7 years 9 months. Cage subsidence often showed a gradual increase over time. At final follow-up, subsidence averaged 4.0 mm on the cranial surface and 2.7 mm on the caudal surface. Although the average increase of disk height was 3.2 mm immediately postoperatively, the final disk height decreased by 4.2 mm on average from that time. The degree of cage subsidence and decrease of disk height were not correlated with the final clinical results. Subsidence was not correlated with bone mineral density in the vertebral body, body weight, or site of the insertion. On the other hand, the wedge shape of the cage and the thickness of the resected endplate had a significant influence on cage subsidence.

While various surgical procedures have been developed for the treatment of atlantoaxial subluxation due to rheumatoid arthritis, C1-C2 intra-articular screw fixation was developed to reduce intraoperative injuries to vertebral arteries. The purpose of this study was to report the therapeutic outcome of this procedure, which was followed for >2 years. Preoperative symptoms were alleviated in all patients. Only 1 patient with subaxial canal stenosis underwent additional laminoplasty during follow-up. All patients with class IIIA or milder neural deficit according to Ranawat's classification showed improvement to class I or II. There were no surgery-related complications or incidents, including injuries to vertebral arteries. Bone union was observed in all patients. No change was observed in the reduced atlas-dens interval during follow-up. The atlantoaxial angle was -6 degrees to 30 degrees (average, 19.4 degrees) at follow-up, and was >or=30 degrees after surgery (fusion in an overextended position) in only 1 patient. Although postoperative deterioration of cervical alignment was observed in 4 patients (18.2%), there was no additional surgery due to deterioration of cervical alignment. With no surgery-related complications or incidents, this procedure could be a safe and acceptable option for atlantoaxial subluxation due to rheumatoid arthritis.

Study Design: Prospective study., Objective: To evaluate our treatment outcome for spinal metastases using our treatment strategy based on prognostic scoring system., Summary of Background Data: In the treatment of spinal metastases, life expectancy is most important, and our scoring system for metastatic spine tumor prognosis has been useful for such prognostic evaluation., Methods: Conservative treatment or palliative surgery was indicated in patients with a predicted prognosis of less than 6 months or in those with multiple vertebral metastases, whereas excisional surgery was performed in patients with a predicated prognosis of 1 year or more, or with a predicted prognosis of 6 months or more, and with metastasis in a single vertebra. One hundred eighty-three patients were prospectively treated according to this principle using our prognostic scoring system, and the outcome was evaluated., Results: The consistency rate between the predicted prognosis from the criteria of the scoring system and the actual survival period was high in patients within each score range (0-8, 9-11, or 12-15), 87.9% in the 183 patients. Only the palliative surgery group (n = 55) showed a significant improvement of the Barthel index between before and after treatment (P < 0.01). The mean maximum Barthel index after treatment in any modality ran parallel to the total scores of our scoring system., Conclusion: The prognostic criteria using our scoring system were useful for the pretreatment evaluation of prognosis irrespective of the treatment modality. In any treatment, the survival period of the patients affected the functional prognosis; therefore, it may be appropriate and realistic to select treatment methods by giving first priority to the life expectancy of patients.

Metastatic spine tumors cause the loss of the supporting function of the spine through vertebral destruction or invade and compress the spinal cord or cauda equine. As a result, metastatic spine tumor causes severe pain, paralysis, or impairment of activities of daily living (ADL). Also, because the finding of metastatic foci in the spine suggests a generalized disorder, life expectancy and treatment options have many limitations. For this reason, treatment is primarily symptomatic, and the major goals in selecting therapeutic modalities are to relieve pain, prevent paralysis, and improve ADL. This article discusses the selection of treatment for metastatic spine tumors and, in particular, the indications for surgical treatment.

Study Design: A multicenter cohort study was performed retrospectively., Objective: To identify radiographic predictors for the development of myelopathy in patients with ossification of the posterior longitudinal ligaments (OPLL)., Summary of Background Data: The pathomechanism of myelopathy in the OPLL remains unknown. Some patients with large OPLL have not exhibited myelopathy for a long periods of time. Predicting the course of future neurologic deterioration in asyptomatic patients with OPLL is difficult at their initial visit., Methods: A total of 156 OPLL patients from 16 spine institutes with an average of 10.3 years of follow-up were reviewed. Subjects underwent a plain roentgenogram, computed tomography (CT), and magnetic resonance imaging of the cervical spine during the follow-up. The trauma history of the cervical spine, maximum percentage of spinal canal stenosis in a plain roentgenogram and CT, range of motion of the cervical spine, and axial ossified pattern in magnetic resonance imaging or CT were reviewed in relation to the existence of myelopathy., Results: All 39 patients with greater than 60% spinal canal stenosis on the plain roentgenogram exhibited myelopathy. Of 117 patients with less than 60% spinal canal stenosis, 57 (49%) patients exhibited myelopathy. The range of motion of the cervical spine was significantly larger in patients with myelopathy than in those of without it. The axial ossified pattern could be classified into 2 types: a central type and a lateral deviated type. The incidence of myelopathy in patients with less than 60% spinal canal stenosis was significantly higher in the lateral deviated-type group than in the central-type group. Fifteen patients of 156 subjects developed trauma-induced myelopathy. Of the 15 patients, 13 had mixed-type OPLL and 2 had segmental-type OPLL., Conclusion: Static and dynamic factors were related to the development of myelopathy in OPLL.

There have been few reports on the imaging diagnosis and treatment of infection of interbody cages used in posterior lumbar interbody fusion. Even in a patient undergoing posterior lumbar interbody fusion using a metal cage, magnetic resonance imaging (MRI) might be able to diagnose epidural abscesses and diskitis when titanium alloy implants are used. When infection of the instrumented cage is diagnosed, emergency debridement with or without removal of implants, including the cage, appropriate wound closure, and the administration of potent antibiotics is the standard treatment. This article describes the conservative follow-up of a patient with epidural abscess and diskitis following instrumented posterior lumbar interbody fusion using a metal cage without surgical intervention. A 40-year-old man had undergone instrumented posterior lumbar interbody fusion at the L5/S1 level approximately 1 year previously. He suddenly developed a fever (temperature, 38 degrees C) and severe lower back pain without apparent cause. Late infection was suspected from his symptoms and laboratory findings, and a wide spectrum antibiotic was administered. On MRI, the low and high signal areas near the end-plate of L5/S1 were detected by T1- and T2-weighted imaging, respectively, and an abscess was noted around the cage. We recommended debridement as treatment; however, he refused further surgical intervention by reason of symptomatic remission. Therefore, wide spectrum antibiotics were continued. Fortunately, no lower back pain has recurred. Examination by MRI during the clinical course clarified the presence and disappearance of an epidural abscess and diskitis. Although the outcome of this case was fortunate, this conservative treatment is unusual, and is not recommended as standard treatment.

Study Design: A rabbit model of posterolateral intertransverse process spine arthrodesis was used., Objective: To assess the osteogenic potential of hydroxyapatite (HA) sticks soaked with marrow and resultant strength in spinal fusion and effects of various biologic agents, in particular fibronectin (FN) on the strength., Summary of Background Data: Mesenchymal stem cells (MSCs) contained in marrow can differentiate into cells constituting bone, cartilage, muscles and fat. Unlike autogenous bone grafts, prosthetic bone grafts combined with marrow have failed to attain adequate strength of new bone even if they are used with marrow., Methods: Porous HA sticks were used as a vehicle for new bone growth in spinal fusion. In experiment 1, rabbits received 2 HA sticks each with or without iliac marrow into the dorsal subcutaneous muscle. The sticks were explanted 6 weeks after surgery and tested mechanically and histologically. In experiment 2, 6 groups of animals underwent spinal fusions with 6 different bone grafts, either autogenous or prosthetic, and the local osteoinductive activity and mechanical strength of the fusion were evaluated., Results: In experiment 1, the HA sticks implanted with marrow showed histologically more active osteogenesis and were mechanically stronger than those implanted alone. The increase in mechanical strength was significantly higher in the former group. In experiment 2, the spinal fusion with autogenous iliac bone was significantly stronger and more elastic than those with autogenous local bone and HA sticks with or without marrow (P < 0.05). The spinal fusion with HA sticks soaked with FN and marrow was significantly stronger than that with HA sticks soaked with marrow. The local osteogenesis after the fusion with HA sticks soaked with FN and marrow was more active than that with HA sticks plus marrow and HA stick plus FN., Conclusion: The impregnation of marrow into HA sticks produced histologically demonstrable active osteogenesis, possibly due to MSCs incorporated into the sticks. In the group receiving HA sticks soaked with FNand marrow, both osteogenesis and strength were increased to levels comparable to those achieved by spinal fusion with autogenous iliac bone grafts. It can be expected that the additional use of FN, which increases incorporation of MSCs into HA, will improve osteogenesis and hence the strength of the fusion.

Study Design: Retrospective multi-institutional study, Objective: To describe the surgical outcomes in patients with ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL) and to clarify factors related to the surgical outcomes., Summary of Background Data: Detailed analyses of surgical outcomes of T-OPLL have been difficult because of the rarity of this disease., Methods: The subjects were 154 patients with T-OPLL who were surgically treated at 34 institutions between 1998 and 2002. The surgical procedures were laminectomy in 36, laminoplasty in 51, anterior decompression via anterior approach in 25 and via posterior approach in 29, combined anterior and posterior fusion in 8, and sternum splitting approach in 5 patients. Instrumentation was conducted in 52 patients. Assessments were made on (1) The Japanese Orthopedic Association (JOA) scores (full score, 11 points), its recovery rates, (2) factors related to surgical results, and (3) complications and their consequences., Results: (1) The mean JOA score before surgery was 4.6 +/- 2.0 and, 7.1 +/- 2.5 after surgery. The mean recovery rate was 36.8% +/- 47.4%. (2) The recovery rate was 50% or higher in 72 patients (46.8%). Factors significantly related to this were location of the maximum ossification (T1-T4) (odds ratio, 2.43-4.17) and the use of instrumentation (odds ratio, 3.37). (3) The frequent complications were deterioration of myelopathy immediately after surgery in 18 (11.7%) and dural injury in 34 (22.1%) patients., Conclusion: The factors significantly associated with favorable surgical results were maximum ossification located at the upper thoracic spine and use of instrumentation. T-OPLL at the nonkyphotic upper thoracic spine can be treated by laminoplasty that is relatively a safe surgical procedure for neural elements. The use of instrumentation allows correction of kyphosis or prevention of progression of kyphosis, thereby, enhancing and maintaining decompression effect, and its use should be considered with posterior decompression.

Study Design: A retrospective study., Objective: To report the clinical course and significance of postoperative radiolucent zones around pedicle screws., Summary of Background Data: Radiolucent zones around pedicle screws have been considered to indicate loss of fixation, delayed union, or pseudarthrosis. Few reports have described the course and significance of them., Methods: Plain radiographs were evaluated from 190 patients with pedicle screw fixation. When 1 mm or greater circumferential lucency was confirmed around a screw on plain radiographs from 2 or more directions, the patient was judged as clear-zone positive. The course of clear-zone positivity was investigated and the relationships between clear-zone positivity and the following items were investigated: (1) number of levels fused, (2) bone union, (3) posterolateral lumbar fusion versus posterior lumbar interbody fusion, (4) clinical results, (5) bone mineral density, and (6) screw types., Results: Although clear zones were observed in 78 patients 6 months after surgery, the clear zone-positive rate decreased over time and the progression of bone union and the number of patients decreased to 28 at the final follow-up 3 years or more after surgery. Interobserver and intraobserver coefficient of variability in clear-zone judgment was over 0.86, and agreement was over 96%. At final follow-up, pseudarthrosis was found in 15 patients. Although the predictive value of the positive test for the presence of clear zones for pseudarthrosis at final follow-up was 0.50, sensitivity was 0.93 and specificity was 0.92. There were significant differences in the clear zone-positive rate in the number of levels fused and bone mineral density among the investigated items., Conclusion: As approximately two thirds of the clear zones disappeared over time, the presence of clear zones did not necessarily mean pseudarthrosis. However, clear zones persisting for 2 years or longer after surgery are a great risk of pseudarthrosis. Therefore, careful observation of clear zones around pedicle screws is of great significance as an evaluation of bone union.

Study Design: A retrospective study., Objective: To investigate the long-term course of patients with delayed union after posterior fusion with pedicle screw fixation (PS) for degenerative lumbar disease., Summary of Background Data: There have been few studies on the long-term course of patients with delayed union after posterior fusion with PS., Methods: The subjects were 48 patients (54 discs) with delayed union 2 years after PS, who showed no or only mild symptoms, and could be observed for 3 years or longer thereafter. All had received an autograft using iliac bones, and the method was posterior lumbar interbody fusion in 12 disc levels and posterolateral lumbar fusion in 42 disc levels. Delayed union occurred in 28 disc levels with neurologically responsible lesions (Group A) and in 26 disc levels at the ends of multilevels fusions (Group B). Serial changes in radiographic and clinical findings were evaluated., Results: In Group A, bone union was observed more than 2 years after surgery in 10 disc levels of 9 patients (34.6%). In Group B, bone union was observed in 4 disc levels of 4 patients (18.2%). In the bone union group of both groups, the mean maximum postoperative intervertebral range of motion was significantly smaller than that in the persistent delayed union group (P < 0.05). The disc height generally decreased with time, but the decrease was significantly larger in the bone union group (P < 0.05). In both groups, clinical results were excellent or good in 100% of patients. No significant difference was noted between the bone union and persistent delayed union groups., Conclusion: Bone union occurred more than 2 years after posterior fusion with PS in about 30% of patients with delayed union. Its occurrence was related to the intervertebral range of motion and disc height. Firm bone union was not necessarily essential for good clinical results.

Bone pain and pathological fractures due to spinal metastases result in severe disorders of ADL (activities of daily living). Osteoclastic pathology by metastases is local bone metabolism disorders by an activation of osteoclast by oncocyte. Therefore, early detection and treatment are important, and radiation therapies and stabilization surgeries have been performed as local treatment. Bisphosphonate therapy to plan pain relief and prevention of enlargement of metastases came to be performed recently by depression of bone resorption. We should aggressively perform combination therapies against bony pain due to metastases.

The Oswestry Disability Index (ODI) is one of the most used assessment scales for patients with spine conditions, and translations into several languages have already been available. However, the scale's discriminative validity and responsiveness to the clinical change was somewhat understudied in these translated versions of the ODI. In this study, we independently developed a Japanese version of the ODI, and tested its discriminative and responsive performances among outpatients with various spinal conditions. We recruited 167 outpatients from seven participating clinics, and concurrently measured the translated ODI and MOS Short Form 36 (SF36) as a reference scale. We also obtained from medical records clinical information such as diagnoses, the past history of surgery, and existence of subjective symptoms and clinical signs. For testing discriminative validity, scores were compared by the number of symptoms and signs, with the trend test. Receiver operating characteristics (ROC) analysis was also conducted to compare ODI and SF36 in their performance to discriminate the existence of signs/symptoms, by chi-square test on the area under ROC curve (AUC). For 35 patients (17 clinically stable, 18 undergoing surgery and clinically significantly changed), the two scales were repeatedly administered after 3-6 months to compare responsiveness by using ROC analysis. The translated ODI and the SF36 Physical Function (PF) subscale showed a significant trend increase as the numbers of symptoms/signs increased. They also showed comparable performance in discriminating the existence of signs/symptoms (AUC=0.70-0.76 for ODI, 0.69-0.70 for SF36 PF, P=0.15-0.81), and clinical status change over time (AUC=0.82 for ODI, 0.72 for SF36 PF, P=0.31). Our results showed that the translated Japanese ODI showed fair discriminative validity and responsiveness as the original English scale showed.

Study Design: This study attempts to determine the molecular changes in intervertebral disc degeneration of rats induced by passive cigarette smoking., Objectives: To quantitate and compare the gene expression levels in intervertebral discs from passively cigarette smoking rats and nonsmoking rats., Summary of Background Data: The molecular mechanism of intervertebral disc degeneration has been investigated mainly in vitro but little in vivo, and gene expression analysis has been performed in a few studies. The cigarette smoking is a risk factor of low back pain. We developed a smoking box to create a rat model of intervertebral disc degeneration induced by passive cigarette smoking., Methods: Total RNA was extracted from intervertebral discs of rats that were raised in a cigarette-smoking box for 2 to 7 weeks. After synthesis of cDNA, the quantitative analysis of gene expression was performed by the real-time PCR. The remaining spines were subjected to the histologic examination., Results: Histologic changes of the nucleus pulposus and the anulus fibrosus were detected after 2 weeks of smoking and were frequently found after 7 weeks. Collagen genes were downregulated remarkably after 7 weeks of smoking. No significant increase was observed in the expressions of matrix metalloproteinase-3, but the expression of tissue inhibitor of metalloproteinases-1 started to increase at 4 weeks of smoking. Aggrecan also started to be up-regulated at 4 weeks., Conclusions: Changes in gene expression by passive cigarette smoking precede the histologic changes in the intervertebral discs. Reactions to suppress the destruction of tissue matrix and to regenerate the intervertebral discs are occurring at the same time as the degenerative histologic changes.

Study Design: A reliability study was conducted., Objective: To report the utility of the ossification- kyphosis angle of a decompression site in the sagittal view of MRI in the preoperative evaluation of the effectiveness of posterior decompression for patients with ossification of the posterior longitudinal ligament in the thoracic spine., Summary of Background Data: In patients with ossification of the posterior longitudinal ligament, in the thoracic spine, posterior decompression may not always be effective for those with physiologic kyphosis; however, posterior decompression is sometimes useful for patients with multilevel lesions or with ossification of the ligamentum flavum. Therefore, it is necessary to evaluate the indications or limitations of posterior decompression before surgery., Methods: The indications or limitations of posterior decompression for this disease were reviewed from the findings of intraoperative ultrasonography and various parameters on preoperative imaging in 22 patients with thoracic myelopathy., Results: Thirteen patients had echo-free space and 9 patients had no echo-free space in intraoperative ultrasonography after posterior decompression. In the kyphosis angle of the decompression site and the configuration of the maximal prominent OPLL, there was no significant difference between the group with echo-free space and the group without echo-free space (P = 0.49, P = 0.55). On the other hand, the ossification-kyphosis angle of the decompression site was more than 23 degrees in all patients with no echo-free space (23 degrees -34 degrees , 28.2 degrees +/- 3.6 degrees ), and it was less than 23 degrees in all patients with echo-free space (10 degrees -23 degrees , 17.4 degrees +/- 4.1 degrees ). There was also significant difference between the groups statistically (P < 0.01, P = 1.50789E-06). In addition, in the occupation rate of the greatest prominence of the OPLL, there was statistically significant difference between the groups (P = 0.032)., Conclusion: The ossification-kyphosis angle in the sagittal view of MRI has potential as an indicator of the effectiveness of posterior decompression in this disease. It is thought that there is a critical point of posterior decompression at nearly 23 degrees of the ossification-kyphosis angle of the decompression site. When the ossification-kyphosis angle is more than 20 degrees , the presence of echo free space should be carefully confirmed in intraoperative ultrasonography.

Study Design: A semi-prospective clinical study was conducted., Objectives: To evaluate the accuracy of a revised scoring system predicting metastatic spinal tumor prognosis and the suitability of the subsequent treatment strategy., Summary of the Background Data: We used a scoring system for the preoperative evaluation of the prognosis of metastatic spinal tumors and selected treatment methods for the predicted prognosis. In the previous version of our scoring system, the reliability of the predicting prognosis was 63.3% in 128 patients with metastatic spinal tumors., Methods: The study participants were 164 patients who died after surgery and 82 who died after conservative treatment. Six parameters were used in the revised scoring system. Each parameter ranged from 0 to 5 points, and the total score was 15 points. In principle, conservative treatment or palliative procedures were indicated in patients with a total score of 8 or less (predicted survival period, less than 6 months) or those with multiple vertebral metastases, while excisional procedures were performed in patients with a total score of 12 or more (predicted survival period, 1 year or more) or those with a total score of 9 to 11 (predicted survival period, 6 months or more) and with metastasis in a single vertebra. The selection of treatment modality was followed faithfully according to the criteria of the revised scoring system after 1998. The prognosis predicted by the revised scoring system and the actual survival period after treatment were compared, and the reliability of the prognostic criteria was analyzed for the group subjected to it prospectively after 1998 (n = 118) and for all 246 patients it was applied to retrospectively., Results: The total score for each patient could be correlated with the survival period. This correlation was also observed in each treatment group. The consistency rate between the predicted prognosis from the criteria of the total scores and the actual survival period was high in patients within each score range (0-8, 9-11, or 12-15), 86.4% in the 118 patients evaluated prospectively after 1998, and 82.5% in the 246 patients evaluated retrospectively. Furthermore, a similar result was also observed in both the surgical procedure group and conservative treatment group. The rate of consistency between the predicted prognosis and the actual survival period in each local extension of the lesion was 75% or more in all types, excluding Type 6 in the surgical classification of Tomita et al., Conclusion: The prognostic criteria using the total scores from our revised scoring system were useful for the pretreatment evaluation of metastatic spinal tumor prognosis irrespective of treatment modality or local extension of the lesion.

Objective: We constructed a passive cigarette-smoking model with rats to investigate the molecular mechanism of intervertebral disc degeneration, and found by gene expression analysis that passive cigarette smoking stimulated the stress-responsive signal pathway and inhibited the apoptotic pathway. In this study, to clarify that these changes were derived from either nucleus pulposus (NP) or annulus fibrosus (AF), we separately collected NP and AF and quantitatively analyzed gene expression., Methods: Total RNA was extracted from NP and AF of the lumbar intervertebral discs from rats which were kept in a smoking box for 4 and 8 weeks. Gene expression was measured by real-time PCR of cDNA synthesized from the total RNA., Results: Stress-responsive protein, heat shock protein 70, was expressed similarly in NP and AF, and was upregulated to the same degree after 8 weeks of passive cigarette smoking. The protein tyrosine phosphatase gene was expressed more strongly in AF than in NP, and was upregulated after 8 weeks of smoking in both tissue parts. The type II collagen and aggrecan genes were predominantly expressed in AF and NP, respectively., Conclusion: These results indicate that passive cigarette smoking stimulates both NP and AF, and induces the stress-responsible genes such as heat shock protein 70 and protein tyrosine phosphatase in both., (Copyright (c) 2005 S. Karger AG, Basel.)

We have investigated the intervertebral discs of rat-smoking models to demonstrate that smoking is a cause of degenerative intervertebral disc disease. A smoking box was developed for this study. We exposed 8-week-old rats to indirect tobacco smoke inhalation. Each rat was forced to inhale the smoke from one cigarette per hour. The mean blood nicotine level of rodents exposed to cigarette smoke corresponds to about twice that of ordinary human smokers. Histological and immunological studies were then performed to assess the effects of smoking for varying periods of time. After 8 weeks, the chondrocytes in the disordered annulus fibrosus layer tended to grow larger and attain a rounder form than normal chondrocytes. The interleukin-1beta level in the 8-week smoking group was significantly higher than that of the control group. Tobacco smoke inhalation increased local production and release of inflammatory cytokines and resultant decomposition of chondrocyte activity.

The Japan Spine Research Society carried out a nationwide survey on complications of the spine, enrolling a total of 16 157 patients who had undergone spine surgery in 196 institutes in the 1-year period from January to December 2001. Diseases, surgical procedures, and complications were surveyed in detail. Forty-nine percent of patients were aged 60 years or older, which was remarkably increased in comparison with the percentage reported by the 1994 survey (37.3%). The number of cases with degenerative spinal diseases comprised 78.2% of the total number of spine surgery cases. The percentage of patients with stenosis was the greatest (38.5%), reflecting the increase in the elderly population undergoing spine surgery. Spinal instrumentation was used with 5497 patients (34.0%). The frequency of its use was much greater than that reported in 1994 (27.0%). The pedicle screw was the most frequently used instrument (54.6%). The use of spinal instrumentation greatly increased for spinal deformity, trauma, and tumors. Posterior lumbar interbody fusion has been increasingly used in cases of lumbar degenerative disease. Complications of spinal surgery were reported in 1383 patients (8.6%). The incidence of complications associated with instrumentation surgery was 12.1%, being twice as much as that associated with noninstrumentation surgery (6.8%).