Takatomo Mine

Innervation of nociceptors in the menisci of the knee joint: an immunohistochemical study.

Abstract Using histology, we studied the innervation of nociceptors in the medial and lateral menisci of the knee joint. Specimens examined were taken from 16 patients during arthroplasty. The patients were 6 men and 10 women, with ages ranging from 14 to 76 years (mean 56 years). Immunohistochemistry with the unlabeled antibody biotin-streptavidin method was employed to detect protein gene product 9.5 (PGP 9.5) or substance P (SP) in the specimen. The antibody for PGP 9.5 detected nerve tissues in the menisci. Most but not all of the nerve fibers were associated with blood vessels. Nerve fibers and sensory receptors were found mainly in the peripheral, vascular zone, representing the outer one-third of the meniscus, and the innervated area was wider in the anterior and posterior horns. Pacinian and Ruffini corpuscles as well as free nerve endings were identified in these areas. Larger fibers coursed circumferentially in the peripheral zone, with smaller branches of nerve fibers running radially into the meniscus. Nerve fibers positive for SP were also detected in the menisci, but were fewer in number. Their branches also were fewer, oriented radially and paralleling blood vessels. This study showed that some of the pain in cases of meniscal tear could originate in the meniscus itself, especially with peripheral tears that may be accompanied by bleeding.

Effects of Basic Fibroblast Growth Factor on the Repair of Large Osteochondral Defects of Articular Cartilage in Rabbits: Dose–Response Effects and Long-Term Outcomes

Articular cartilage possesses a limited capacity for self-renewal. The regenerated tissue often resembles fibrocartilage-like tissue rather than hyaline cartilage, and degeneration of the articular surface eventually occurs. The purpose of this study was to investigate the effect of basic fibroblast growth factor (bFGF) on the healing of full-thickness articular cartilage defects. bFGF (0, 10, 50, 100, 250, 500, or 1000 ng) was mixed with collagen gel and implanted into full-thickness articular cartilage defects drilled into rabbit knees. The repaired tissue was examined grossly and histologically, and was evaluated with the use of a grading scale at 4, 12, 24, and 50 weeks. At 4 weeks, treatment with 100 ng of bFGF had greatly stimulated cartilage repair both grossly and histologically in comparison with untreated defects (those filled with plain collagen gel). The average total scores on the histological grading scale were significantly better for the defects treated with bFGF than for the untreated defects. These improvements were evident as long as 50 weeks postoperatively, although slight deterioration was noted in the repaired cartilage. Immunohistochemical staining for type II collagen showed that this cartilage-specific collagen was diffusely distributed in the repaired tissue at 50 weeks. These findings suggest that bFGF may be a practical and important candidate for use in cartilage repair.

Expression of RANKL/OPG during bone remodeling in vivo

The interaction between receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) plays a dominant role in osteoclastogenesis. As both proteins are produced by osteoblast lineage cells, they are considered to represent a key link between bone formation and resorption. In this study, we investigated the expression of RANKL and OPG during bone remodeling in vivo to determine the relationship between osteoclastogenic stimulation and osteoblastic differentiation. Total RNA was prepared from rat femurs after marrow ablation on days 0, 3, 6, and 9. The temporal activation patterns of osteoblast-related genes (procollagen α1 (I), alkaline phosphatase, osteopontin, and osteocalcin) were examined by Northern blot analysis. An appreciable increase in the expression of these osteoblast markers was observed on day 3. The peak increase in gene expression was observed on day 6 followed by a slight reduction by day 9. Real-time PCR analysis showed that the OPG mRNA expression was markedly upregulated on day 6 and slightly decreased on day 9. In contrast, RANKL mRNA expression was increased by more than 20-fold on day 9. The RANKL/OPG ratio, an index of osteoclastogenic stimulation, peaked on day 9. Histological analysis showed that RANKL and OPG immunoreactivity were predominantly associated with bone marrow cells. The expression of bone formation markers was activated in the bone formation phase, followed by the stimulation of RANKL/OPG expression in the bone resorption phase, which confirmed that these molecules are key factors linking bone formation to resorption during bone remodeling.

Venous thromboembolism after total joint arthroplasty: results from a Japanese multicenter cohort study

IntroductionReal-world evidence of the effectiveness of pharmacological thromboprophylaxis for venous thromboembolism (VTE) is limited. Our objective was to assess the effectiveness and safety of thromboprophylactic regimens in Japanese patients undergoing joint replacement in a real-world setting.MethodOverall, 1,294 patients (1,073 females and 221 males) who underwent total knee arthroplasty (TKA) and 868 patients (740 females and 128 males) who underwent total hip arthroplasty (THA) in 34 Japanese national hospital organization (NHO) hospitals were enrolled. The primary efficacy outcome was the incidence of deep vein thrombosis (DVT) detected by mandatory bilateral ultrasonography up to post-operative day (POD) 10 and pulmonary embolism (PE) up to POD28. The main safety outcomes were bleeding (major or minor) and death from any cause up to POD28.ResultsPatients undergoing TKA (n = 1,294) received fondaparinux (n = 360), enoxaparin (n = 223), unfractionated heparin (n = 72), anti-platelet agents (n = 45), or no medication (n = 594). Patients undergoing THA (n = 868) received fondaparinux (n = 261), enoxaparin (n = 148), unfractionated heparin (n = 32), anti-platelet agents (n = 44), or no medication (n = 383). The incidence rates of sonographically diagnosed DVTs up to POD10 were 24.3% in patients undergoing TKA and 12.6% in patients undergoing THA, and the incidence rates of major bleeding up to POD28 were 1.2% and 2.3%, respectively. Neither fatal bleeding nor fatal pulmonary embolism occurred. Significant risk factors for postoperative VTE identified by multivariate analysis included gender (female) in both TKA and THA groups and use of a foot pump in the TKA group. Only prophylaxis with fondaparinux reduced the occurrence of VTE significantly in both groups. Propensity score matching analysis (fondaparinux versus enoxaparin) showed that the incidence of DVT was lower (relative risk 0.70, 95% confidence interval (CI) 0.58 to 0.85, P = 0.002 in TKA and relative risk 0.73, 95% CI 0.53 to 0.99, P = 0.134 in THA) but that the incidence of major bleeding was higher in the fondaparinux than in the enoxaparin group (3.4% versus 0.5%, P = 0.062 in TKA and 4.9% versus 0%, P = 0.022 in THA).ConclusionsThese findings indicate that prophylaxis with fondaparinux, not enoxaparin, reduces the risk of DVT but increases bleeding tendency in patients undergoing TKA and THA.Trial registrationUniversity Hospital Medical Information Network Clinical Trials Registry: UMIN000001366. Registered 11 September 2008.

Ultrastructural observations on the ossification of the supraspinous ligament

Study Design This study analyzed the process of ossification of spinal ligaments, Supraspinous ligaments excised during surgery were studied by light and scanning electron microscopy. Objectives. The results were correlated to determine the mechanism of ossification of spinal ligaments Summary of Background Data. Ossification of the ligamentum flavum has been described in detail by Hiraoka, yamaguchi, and others. However, the pathogenesis of ossification of the spinal ligaments remains unclear. Some studies have been performed by light and transmission electron microscopy, but no detailed investigtion of the ossification of the spinal ligaments by scanning electron microscopy has been performed. Methods Specimens of supraspinous ligament were taken from 41 patients during spinal surgery. Ossification was diagnosed macroscopically and radiologically for 20 patients. The specimens were examined using light and scanning electron microscopy. Results Collagen fibrils were 700–2000 A in diameter and were arranged in parallel. The ligament insertion divided into four zones and seemed to fit the description of Enthesis histologically. Close to the ossification region, there were a region in which some fibrils were thinner and branchings became slightly stronger, tending to form bridges of minute fibrils between other fibrils. Close to the region of actual ossification, there was a region in which extra-fibrillar substances completely deposited. In the region of actual ossification, there were medullary spaces of varying sizes, and the surrounding collagen fibers were dense and arranged in a lamellar fashion. Osteocyte lacunae had formed and the cells regarded to be the osteocytes were present on the inside. Conclusion Ossification of the supraspinous ligament possibly occurs as follows. Fibrob lasts or chondrocyte-like cells respond to some external stimulus, form an irregular network of fine fibrils, and produce acid mucopolysaccharide. These undergo calcification and capillary invasion. Undifferentiated mesencymal cells invade and are transformed into osteoblasts. Then osteogenesis ensues with progressive calcification.

Effect of progestins with different glucocorticoid activity on bone metabolism

Objective  Progestins are commonly prescribed for hormone replacement therapy (HRT) and contraception. However, the effects of progestins on bone metabolism remain unclear and are often controversial.

Locked knee caused by intraarticular ganglion

Intraarticular ganglion cyst arising from the cruciate ligament is difficult to diagnose by clinical symptom. In our case, Cyst attached anteriorly to posterior cruciate ligament, and limited both flexion and extension of knee. The cyst was excised in a piecemeal fashion arthroscopically. Knee pain and limitation in knee motion disappeared by the day after surgery. We hypothesize that reason of restriction of extension is impingement between anterior cruciate ligament and intracondylar, and reason of restriction of flexion is stimulation nerve ending in the synovial membrane stretched with knee motion.

Intra-articular synovial cyst of the knee joint: a case report

Synovial cysts occur secondary to injury, mucinous degeneration or tumours. We report a patient with snapping of the knee joint caused by a synovial cyst located near the patellofemoral joint which developed as a result of minor trauma.

A giant rheumatoid nodule

Subcutaneous rheumatoid nodules occur commonly in advanced cases of rheumatoid arthritis and are the most common extra-articular lesion of this disease. We present a case of a very unusual giant rheumatoid nodule that developed on the lateral side of a knee. The case was devoid of systemic symptoms of arthritis and the lesion was limited to a rheumatoid nodule. The nodule was successfully treated by surgical excision. However, other new nodules developed in her hand. Her clinical course has not been satisfactory.

In vivo kinematics of a unique posterior-stabilized knee implant during a stepping exercise

BackgroundStair-stepping motion is important in daily living, similar to gait. Knee prostheses need to have even more superior performance and stability in stair-stepping motion than in gait. The purpose of this analysis was to estimate in vivo knee motion in stair stepping and determine if this unique knee prosthesis function as designed.MethodsA total of 20 patients with Bi-Surface posterior-stabilizing (PS) implants were assessed. The Bi-Surface PS knee is a posterior-cruciate substitute prosthesis with a unique ball-and-socket joint in the mid-posterior portion of the femoral and tibial components. Patients were examined during stair-stepping motion using a 2-dimensional to 3-dimensional registration technique.ResultsThe kinematic pattern in step up was a medial pivot, in which the level of anteroposterior translation was very small. In step down, the kinematic pattern was neither a pivot shift nor a rollback. From minimum to maximum flexion, anterior femoral translation occurred slightly.ConclusionsIn this study, this unique implant had good joint stability during stair stepping. The joint’s stability during stair stepping was affected by the design of the femorotibial joint rather than post/cam engagement or the ball-and-socket joint.