Biomechanical study of optimum anchorage in dome-shaped high tibial osteotomy.

PURPOSE: There has been no report to date on any biomechanical study regarding the strength of fixation at the osteotomy site in dome-shaped high tibial osteotomy (HTO). In this study, we evaluated the biomechanical strength of a spacer that we improved and determined the medial site of HTO. METHODS: HTO correction angles of 15° and 20° were used in all experiments, which were performed on lower leg specimens from pigs ( n = 12). The osteotomy site was fixed by a locking plate and screws with a spacer. Compression (600 N/min until 1100 N) and extended cyclic loading (200 cycles at 1000-2000 N) were performed to compare initial displacements in HTO specimens with and without spacers. RESULTS: The reduction ratios of displacement with and without spacers at HTO correction angles of 15° and 20° were 37% and 27%, respectively. No effect of the spacer at the correction angle of 15° was observed in the cyclic loading; however, the maximum displacement and amplitude were reduced with the spacer at the correction angle of 20°. CONCLUSIONS AND CLINICAL RELEVANCE: When the HTO correction angle is small, the effect of the spacer is uncertain. However, the spacer is effective at an HTO correction angle of 20°.

A case report: locking because of cyclops syndrome occurring after partial rupture of the anterior cruciate ligament.

There have been a few reports of cyclops syndrome following a partial rupture of the anterior cruciate ligament (ACL) without surgical reconstruction. We have reported for the first time a case of cyclops lesion with locking symptoms after partial rupture of the ACL. A 14-year-old girl twisted her right knee when landing after a jump while playing basketball, and locking symptoms of the knee appeared. Cyclops syndrome occurred because of a partial rupture of the posterolateral bundle of the ACL was diagnosed and removed as a lump by punch. After resection of the lesion, the locking symptom was no longer observed.

Fibronectin regulates proteoglycan production balance in transforming growth factor-ß1-induced chondrogenesis.

Transforming growth factor (TGF)-ß and bone morphogenetic protein (BMP) induce a cartilage-specific extracellular matrix (ECM) gene, aggrecan, in a chondrogenic cell line, ATDC5. The results of our recent study show that TGF-ß1, but not BMP-4, strongly induces an ECM gene, fibronectin, during chondrogenesis. However, the role of fibronectin in chondrogenesis is unclear. In the current study, our results showed that TGF-ß1, but not BMP-4, led to versican-dominant proteoglycan production during chondrogenesis of ATDC5 cells. siRNA-mediated reduction of fibronectin and interference in the liaison between fibronectin and integrins by the Arg-Gly-Asp-Ser (RGDS) peptide increased aggrecan expression, and decreased versican expression by TGF-ß1 stimulation. These data suggest that fibronectin is a critical mediator for TGF-ß-specific production balance of 2 major proteoglycans, aggrecan and versican, during chondrogenesis.

The anterior trochlear line as a reference for femoral component positioning in total knee arthroplasty.

PURPOSE: A new radiographic method using the anterior and posterior femoral condyles as a landmark to determine the rotational alignment of the femoral component in TKA had been developed. METHODS: The new radiograph presents an axial view of the distal femur. The patients were asked to lie in the supine position and flex the knee approximately 120° to 130°. Radiographs were applied at an inclination angle of 20° to 30°. The condylar twist angle (CTA), the external rotational angle between the posterior condylar (PC) line and the clinical transepicondylar axis (TEA), and the trochlear line angle (TLA), and the internal rotational angle between the anterior trochlear line and the clinical TEA were measured. Images were taken of 129 knees in 87 patients with osteoarthritis of the knee. The measurement values obtained using our method with those obtained using 3D reconstructed images from a 3-dimensional helical CT system (n = 35) were compared. RESULTS: The average CTA was 5.7° ± 2.8° and the average TLA was -5.6° ± 3.2°. The CTA was negatively correlated with the tibiofemoral angle (TFA). The average TLA was positively correlated with the TFA. The average difference between the TLA values obtained with this view and those obtained using the 3D-CT was 0.5° ± 1.6°. The relationship between the radiograph and 3D-CT in TLA was higher than that in CTA. CONCLUSIONS: This radiographic technique allows easy and simultaneous measurement of the CTA and TLA and may provide an alternative method for assessing the TEA of the femur during preoperative planning for TKA.

Synovial hemangioma of the knee joint in a 3-year-old girl.

Synovial hemangioma has been reported to be relatively rare, and usually occurs in childhood and adolescence. However, there are a few reports of the disease in infants. In this report, we diagnosed synovial hemangioma in a 3-year-old girl who had swelling and pain in her left knee. Gadolinium-enhanced magnetic resonance imaging revealed abnormal intensity in an intra-articular lesion. We performed arthroscopy, and arrived at a final diagnosis based on a scopic biopsy. Synovial hemangioma should be considered as a possible diagnosis in infants with swelling and pain in the knee.

An Asian case of fibroblastic rheumatism: clinical, radiological, and histological features.

We report a case of fibroblastic rheumatism (FR) in a 61-year-old woman. The patient showed sclerodactyly and polyarthritis that involved both her hands and feet joints. Levels of C-reactive protein and matrix metallopeptidase-3 were within normal range. We diagnosed her condition as FR according to both the clinical features characterized with the destructive change of multiple joints and the histological sample. This is the first FR published case of FR in an Asian individual, and 23 published cases were reviewed.

Proposed novel unified nomenclature for range of joint motion: method for measuring and recording for the ankles, feet, and toes.

The Ad Hoc Committee of Terminology of the Japanese Society for Surgery of the Foot (JSSF) proposes novel terminology for motion of the ankle, foot, and toe because there are some ambiguities in the current terminology. Articles were identified by searching the electronic databases of PubMed that compared definitions of American Orthopaedic Foot and Ankle Society (AOFAS), International Society of Biomechanics (ISB), and in the textbook of Kapandji as well as the American Academy of Orthopaedic Surgeons (AAOS). A total of 11 articles described the transverse (horizontal) plane motion in the hindfoot as external rotation/internal rotation and 10 as abduction/adduction. In all, 2 articles described the transverse (horizontal) plane motion in midfoot as external rotation/internal rotation and 10 as abduction/adduction. Another 4 articles described the transverse (horizontal) plane motion in the forefoot as external rotation/internal rotation and 8 as abduction/adduction. Altogether, 109 articles described the sagittal plane motion of the foot/ankle as dorsiflexion/plantarflexion and 20 as extension/flexion. In all, 99 articles described the frontal (coronal) plane motion of the foot/ankle as inversion/eversion and 4 as supination/pronation. Furthermore, 12 articles described the sagittal plane motion of toes as dorsiflexion/plantarflexion and 15 as extension/flexion. Another 16 articles described the frontal (coronal) plane motion of toes as supination/pronation and 1 as inversion/eversion. The transverse (horizontal) plane motion of the foot/ankle was defined as abduction/adduction in the hindfoot, midfoot, and forefoot; the sagittal plane motion of the foot/ankle was defined as dorsiflexion/plantarflexion; and the frontal (coronal) plane motion of the foot/ankle as inversion/eversion. The transverse (horizontal) plane motion of toes was defined as abduction/adduction; the sagittal plane motion of toes was defined as extension/flexion; and the frontal (coronal) plane motion of toes was defined as supination/pronation.

Genetic heterogeneity in rheumatoid arthritis mouse models induced by extrinsic and intrinsic factors.

A cumulative effect of the susceptibility genes with polymorphic alleles may be responsible for rheumatoid arthritis (RA). The objective of this study was to clarify whether susceptibility to RA is under the control of common allelic loci between two different RA models induced by extrinsic and intrinsic factors, collagen-induced arthritis (CIA) in DBA/1 mice and arthritis in MRL/Mp (MRL) mice associated with the Fas deficient mutant gene, Fas(lpr), respectively. CIA was examined in mice of parental DBA/1 and MRL, (MRL x DBA/1) F1 and (MRL x DBA/1) F2 progenies. In genome-wide screening of the severity in the F2 using microsatellite markers, significant linkage was observed on chromosomes 5 and 17 at map position of D5Mit259 and H-2, respectively, associated with DBA/1 alleles, while there was no loci associated with arthritis of MRL-Fas(lpr) mice previously identified. In a quantitative trait locus (QTL) analysis, the locus on chromosome 5 showed the highest peak at map position 35 cM (LOD score 6.0). This study may indicate that the arthritis induced by extrinsic and intrinsic factors is under the control of a different combination of susceptibility genes with common and different alleles, possibly simulating the genetic heterogeneity of RA.

Pharmacological shift of the ambiguous nitric oxide action from neurotoxicity to cyclic GMP-mediated protection.

OBJECTIVES: The effect of intracellular cyclic guanosine monophosphate (GMP) increase on neuronal damage was tested using a newly developed nitric oxide-related injury model of cultured spinal cord neurons. METHODS: Neuronal damage after 24-hour-exposure to sodium nitroprusside (SNP), a nitric oxide (NO) donor, was evaluated by measuring the activity of released lactate dehydrogenase from injured neurons. RESULTS: Oxygen radical scavengers had a protective effect, indicating that the neuronal damage, elicited by 10 µM SNP, was largely due to peroxynitrite formation. Alternatively, a strong inhibition of the NO-induced damage could also be achieved by an intracellular cyclic GMP increase resulting from the addition of 100 µM 8-bromo-cyclic GMP. Propentofylline (PPF, 1-100 µM), a xanthine derivative and rather selective phosphodiesterase (PDE) inhibitor, enhanced intracellular cyclic GMP elevation induced by SNP exposure. The neuronal damage induced by 10 µM SNP exposure for 24 hours was almost completely blocked in the presence of 1 µM PPF. DISCUSSION: These results suggest that NO has an ambiguous action, i.e. toxic by favoring the formation of, but protective by intracellular cyclic GMP elevation which can be reinforced by PDE inhibition. Therefore, PDE inhibitors, such as PPF, may be useful therapeutic drugs to limit oxidative neuronal damage in the central nervous system.

Activation of epidermal growth factor receptor gene is involved in transforming growth factor-beta-mediated fibronectin expression in a chondrocyte progenitor cell line.

Chondrocytes produce many types of ECM to maintain elasticity and plasticity in articular cartilage of revolute joints. Both transforming growth factor beta (TGF-beta) and bone morphogenetic proteins (BMPs) induce extracellular matrix proteins such as type IIalpha1 collagen and aggrecan during chondrogenic differentiation in vitro. However, differences in the matrix gene expression pattern by the stimulation of TGF-betas and BMPs remains unclear. In the present study, we created a customized PCR-based ECM array to investigate the pattern of ECM expression genes in the chondrocyte progenitor cell line ATDC5, that was stimulated by TGF-betas or BMPs. Fibronectin (Fn) expression was drastically induced after TGF-beta stimulation, but not BMP-4. Epidermal growth factor receptor (Egfr) gene was also significantly activated in TGF-beta1-induced chondrogenic differentiation as compared to BMP-4-mediated differentiation. Furthermore, EGFR-knockdown assay of the cells showed decreasing Fn expression during TGF-beta1-induced chondrogenic differentiation. These data indicated that Egfr gene activation by TGF-beta is involved in the differences in the expression of cellular matrix genes such as Fn, as compared to the expression pattern induced by BMPs.

3-D MRI/CT fusion imaging of the lumbar spine.

OBJECTIVE: The objective was to demonstrate the feasibility of MRI/CT fusion in demonstrating lumbar nerve root compromise. MATERIALS AND METHODS: We combined 3-dimensional (3-D) computed tomography (CT) imaging of bone with 3-D magnetic resonance imaging (MRI) of neural architecture (cauda equina and nerve roots) for two patients using VirtualPlace software. RESULTS: Although the pathological condition of nerve roots could not be assessed using MRI, myelography or CT myelography, 3-D MRI/CT fusion imaging enabled unambiguous, 3-D confirmation of the pathological state and courses of nerve roots, both inside and outside the foraminal arch, as well as thickening of the ligamentum flavum and the locations, forms and numbers of dorsal root ganglia. Positional relationships between intervertebral discs or bony spurs and nerve roots could also be depicted. CONCLUSION: Use of 3-D MRI/CT fusion imaging for the lumbar vertebral region successfully revealed the relationship between bone construction (bones, intervertebral joints, and intervertebral disks) and neural architecture (cauda equina and nerve roots) on a single film, three-dimensionally and in color. Such images may be useful in elucidating complex neurological conditions such as degenerative lumbar scoliosis(DLS), as well as in diagnosis and the planning of minimally invasive surgery.

Effect of troglitazone on tumor growth and pulmonary metastasis development of the mouse osteosarcoma cell line LM8.

BACKGROUND: Osteosarcoma often develops micrometastases in the lung prior to diagnosis, causing a fatal outcome. Therefore, the prevention of pulmonary metastases is critical for the improvement of the prognosis of patients with osteosarcoma. The purpose of this study was to investigate whether troglitazone (TGZ) is considered as possible therapeutics in the treatment of growth and metastasis of osteosarcoma. METHODS: LM8 cells were treated for 3 days with various concentrations of TGZ. The effect of TGZ on cell proliferation was determined by DNA measurement in the cultures and 5-bromo-2'-deoxyuridine incorporation study. The assay of cell invasion and motility was performed using either the Matrigel-coated cell culture inserts or the uncoated cell culture inserts in the invasion chambers. The effect of TGZ on Akt signaling was assessed by Western blot analysis of Akt and p-Akt. The effects of oral administration of either TGZ (TGZ group) or ethanol (control group) on the growth of primary tumor and the development of pulmonary metastasis were examined in nude mice implanted with LM8 cells on their backs. The expression and activity of matrix metalloproteinase 2 (MMP-2) within the tumor were determined by immunohistochemistry and zymography. The microvessel density (MVD) within the tumor was determined by immunohistochemistry for CD34. RESULTS: TGZ dose-dependently inhibits cell proliferation. TGZ-treated cells were less invasive and less motile than untreated cells. The activity of MMP-2 secreted by TGZ-treated cells was lower than that secreted by untreated cells. TGZ decreased the level of p-Akt. The primary tumor mass was smaller in the TGZ group than in the control group. The TGZ group had less metastatic tumors in the lung compared with the control group. The expression and activity of MMP-2 within the tumor of the TGZ group were lower than those of the control group. The MVD within the tumor of the TGZ group was lower than that of the control group. CONCLUSIONS: Inhibition of Akt signaling by TGZ may decrease the secretion of MMP-2, resulting in the decrease of invasiveness and motility in LM8 cells. Treatment of tumor-bearing mice with TGZ decreases the expression and activity of MMP-2 within the tumor, and inhibits primary tumor growth and pulmonary metastasis development. TGZ may offer a new approach in chemotherapy for osteosarcoma.

Arthroscopic technique for fragment fixation using absorbable pins for osteochondritis dissecans of the humeral capitellum: a report of 4 cases.

This is the first report to describe a method of arthroscopic osteochondral fixation using absorbable pins to treat osteochondritis dissecans (OCD) of the capitellum. Four adolescent baseball players with OCD of the capitellum were treated, and good short-term results were obtained. During this arthroscopic procedure, the elbow was maintained in the maximum flexed position, and posterolateral portals were used to visualize the lesion, perform drilling, and insert the pins. This procedure is less invasive and easier to perform than other fixation procedures that require harvesting or production of autologous bone pegs. This is an effective method of fragment fixation with absorbable pins.

Reconstruction using a frozen bone method for osteosarcoma of the talus. A case report and review of the literature.

A case of osteosarcoma of the talus is reported. Osteosarcoma of the talus is very rare. The patient is alive and she has been continuously disease free for five years after surgery. This is the first case of osteosarcoma of the talus with reconstruction using a frozen bone method, an autograft containing tumor treated with liquid nitrogen. This is a rare case report of osteosarcoma of the talus without extrainvasion of the talus.

Correction of hallux valgus deformity using the center of rotation of angulation method.

BACKGROUND: To correct a hallux valgus (HV) deformity quantitatively and prevent unexpected postoperative deformity, the center of rotation of angulation (CORA) method was applied during HV surgery. To correct a hallux valgus (HV) deformity quantitatively and prevent unexpected postoperative deformity, the center of rotation of angulation (CORA) method was applied during HV surgery. METHODS: To create a normal foot model, radiographs of 64 normal female feet were measured. Points A and B were defined as the intersection of the intermetatarsal angle and the HV angle. CORA1 and CORA2 were defined as the intersection of the axes of the first metatarsal and the first proximal phalanx in the normal and HV models, respectively. Procedures to correct HV deformity using the CORA method were devised and were applied to HV feet, which underwent a focal dome osteotomy or medial wedge osteotomy. RESULTS: Point A was 2.3 times the length of the second metatarsal proximally from the top of the second metatarsal head, and point B was 0.17 times the length of the first metatarsal proximally from the top of the first metatarsal head. Two methods were used to correct the deformity. With one method, a focal dome osteotomy was performed at the first metatarsal on the circle at the CORA1 and the distal fragment was moved to the standard first metatarsal axis. The first proximal phalanx was then moved around the metatarsal head to the standard axis of the first proximal phalanx at the CORA2. With the other method, a medial wedge osteotomy was performed on or proximal to the CORA2, and the distal fragment was moved to the first standard metatarsal axis. CONCLUSIONS: We propose a preoperative plan to use the CORA method to correct deformities that prevent translation of the axis or an angulation deformity. HV deformity can be corrected effectively using the CORA method.

Expression of sphingosine kinase 2 in synovial fibroblasts of rheumatoid arthritis contributing to apoptosis by a sphingosine analogue, FTY720.

Gene expression profiles in synovial tissues from rheumatoid arthritis (RA) patients have yielded useful information on the pathogenetic process of the synovitis. In one group of them, sphingosine kinase 2 (SPHK2), a nuclear protein regulating cell proliferation, seemed to be highly expressed, undergoing a different pathogenetic process of synovitis. In the present study it was clarified that SPHK2 was expressed in the synovial fibroblasts of the synovial tissues obtained from the knee joints of the RA patients. In the cultured synovial fibroblasts from these patients, SPHK2 was more highly expressed than that in the human macrophage cell line, THP-1 and human dermal fibroblasts. SPHK2 was expressed in and around the nucleus and transferred to the cytoplasm and cell surface by the administration of epidermal growth factor, associated with the increased expression of sphingosine-1-phosphate. A sphingosine analogue, FTY720, which is activated by phosphorylation specifically by SPHK2, mediated apoptotic signaling of the cultured synovial fibroblasts. These findings suggest that SPHK2 may regulate the autonomous proliferation of synovial fibroblasts as one of the predisposing genes to RA and could be a target for a novel therapeutic strategy for RA.

Intrathecal transplantation of autologous macrophages genetically modified to secrete proenkephalin ameliorated hyperalgesia and allodynia following peripheral nerve injury in rats.

To develop a novel genetic approach for the treatment of pain, we tested the transplantation of gene-transferred autologous macrophages by lumbar puncture. A rat neuropathic pain model was produced by chronic constriction of the sciatic nerve. Autologous macrophages were collected from the intraperitoneal space. Then human proenkephalin gene was transferred into the macrophages by electroporation. The gene-transferred macrophages were transplanted into the subarachnoid space by lumbar puncture. One week after transplantation, the heat hyperalgesia and allodynia induced by sciatic nerve constriction completely remitted. The analgesic action continued until at least 4 weeks after transplantation. The transplanted macrophages migrated into the spinal cord and expressed proenkephalin mRNA and Met-enkephalin protein. The method we tested in the present study may be a safe, simple and effective way to inhibit pain sensation after peripheral nerve injuries.

Resolution of intraspinal retro-odontoid cyst associated with os odontoideum after posterior fixation.

STUDY DESIGN: A case report and review of previous literature. OBJECTIVES: To describe the diagnosis and successful treatment of an intraspinal retro-odontoid cyst associated with an os odontoideum. SUMMARY OF BACKGROUND DATA: Retro-odontoid cysts associated with atlantoaxial instability are extremely rare. Direct excision of the cysts has commonly been performed for the surgical treatment of myelopathy. METHODS: A retro-odontoid cyst in a 58-year-old woman with os odontoideum was treated surgically by posterior fixation between C1 and C3 without resection of the retro-odontoid mass. The patient's history, clinical examination, imaging findings, and treatment are reported. RESULTS: The patient experienced walking difficulty, numbness in the upper and lower limbs, and hypesthesia in both hands. Congenital C2/3 fusion and atlantoaxial instability associated with an os odontoideum were found in the radiographs. Magnetic resonance imaging detected a round retro-odontoid mass, which compressed the spinal cord. The mass showed uniform low intensity on T1-weighted images and uniform high signal intensity on T2-weighted images. Gadolinium-diethylenetriaminepenta-acetic acid-enhanced T1-weighted images showed rim enhancement of the mass with no internal enhancement. Three months after the operation, the mass was no longer visible in a magnetic resonance imaging examination and the patient completely recovered motor function in her extremities. CONCLUSIONS: Posterior fixation without resection was successfully used to eliminate a retro-odontoid cyst associated with atlantoaxial instability.

Laser-guided placement of the tibial guide in the transtibial technique for anterior cruciate ligament reconstruction.

In anterior cruciate ligament (ACL) reconstruction, it is important to determine the location and direction of the femoral bone tunnel when using the transtibial technique. Accurately identifying the anatomic location at which to make the femoral bone tunnel for double-bundle ACL reconstruction is not a straightforward procedure. We describe a new method in which the centrum of the femoral tunnel is marked with an awl and a laser beam-guided technique is used to place the tibial pin. This procedure allows us to mark the desired location of the femoral tunnel before drilling the tibial bone tunnel when using the transtibial technique. This is the first report of a laser-guided technique used in arthroscopic surgery. We used a laser beam to determine the location of the femoral tunnel--the anatomic site needed to perform the intra-articular drilling in the tibia. In this technique, a laser pointer is set at the tibial guide, which reflects the laser beam and illuminates the point where the femoral bone tunnel should be made. Our method offers an easy and accurate way to reconfirm the tibial placement before drilling.