Introduction

Hip-Spine syndrome has various clinical aspects. For example, schoolchild with severe congenital dislocation of the hip have unfavorable standing posture and disadvantageous motions in ADL. Hip-Spine syndrome is closely related closely as the adjacent lumbar vertebrae and the hip joint. Furthermore, not only the pelvis and the lumbar spine, but also the neck position might influence on the maximum hip flexion angle. In this study, we examined the maximum hip flexion angle and pelvic movement angle by observing the lumbar spine, the pelvis and the neck in three different positions.

Background

The patterns and magnitudes of axial femorotibial rotation are variable due to the prosthesis design, ligamentous balancing, and surgical procedures. LCS mobile-bearing TKA has been reported the good clinical results, however, knee kinematics has not been fully understood. Therefore, we aimed to investigate the effects of the weight-bearing (WB) condition on the kinematics of mobile-bearing total knee arthroplasty (TKA).

Introduction

Sacral fractures were previously treated with transiliac bars, sacroiliac screws or posterior plates. Sacroiliac screws are not as invasive, but the risk of intra-operative neurovascular damage must be considered. Posterior plate fixation is slightly invasive. In 2006, we conceived a new fixation method with spinal instrumentation system, and I will introduce it.

Osteoporosis is one of the most common diseases in modern aging society. Receptor activator of nuclear factor-κB ligand (RANKL) plus macrophage colony stimulating factor (M-CSF)-mediated osteoclastogenesis has been recently implicated in the pathogenesis of this disease. Among other causes, the anticoagulant drug heparin is a notable inducer of secondary osteoporosis, although the molecular pathway underlying this process, particularly in human model, has not been clarified yet. Recently, we reported the differentiation of two subtypes of osteoclasts starting from human peripheral blood CD14-positive monocytes (Monocytes), respectively fusion regulatory protein-1 (FRP-1/CD98)-mediated osteoclasts and RANKL+M-CSF-mediated osteoclasts. We, therefore, investigated in details effects of heparin on differentiation and activation using a simple system of human osteoclastogenesis.

When Monocytes were cultured with osteoclastogenesis-relating factors and a high dose of heparin, heparin suppressed osteoclastogenesis in both pathways. However, a proper quantity of heparin enhanced tartrate-resistant acid phosphatase-positive multinucleated giant cell formation. There were significant differences in fusion indices between control osteoclasts and osteoclasts stimulated by moderate concentrations of heparin in two systems (P< 0.05). As a result of osteoclastic activity, FRP-1-mediated osteoclasts treated with a proper quantity of heparin formed larger pits on Ca plates. Moreover, lacunae on dentin surfaces induced by FRP-1-mediated osteoclasts were enhanced with moderate concentration of heparin. In contrast, heparin did not increase pit-formation area on Ca plates and on dentin surfaces by RANKL+M-CSF-mediated osteoclasts. Evaluating the relation between the concentration of heparin and the osteolytic areas on Ca plates, Pearson’s correlation coefficient of the FRP-1 and the RANKL+M-CSF were −0.973 (P< 0.05) and −0.695 (P=0.19), respectively.

In present study, although moderate doses of heparin stimulated differentiation in both systems, in osteoclastic activity, heparin promoted only to the FRP-1 system, not to RANKL+M-CSF system. Our results suggested FRP-1-induced osteoclastogenesis mainly contributes to development of heparin osteoporosis and also that the onset mechanism after long-term administration of heparin may be affected by the characteristic bone resorption ability of FRP-1osteoclasts.

A total of 108 patients with unilateral instability of the knee, associated with rupture of the anterior cruciate ligament, was prospectively randomised for arthroscopic single- or double-bundle reconstruction of the ligament using hamstring tendons. The same postoperative rehabilitation protocol was used for all. The patients were followed up for a mean of 32 months (24 to 36). We measured the anterior laxity and joint position sense at different angles of flexion of the knee to determine whether both bundles in the double-bundle reconstruction contributed to the stability of the joint and proprioception.

No significant difference was found between the two groups with regard to anterior laxity measured by the KT-2000 arthrometer with the knee at 20° or 70° flexion nor with regard to proprioception. A notchplasty was required less often in the double- compared with the single-bundle reconstruction.

We did not find any advantage in a double-bundle as opposed to a single-bundle reconstruction in terms of stability or proprioception.

Friction was studied in 67 retrieved cemented cups with 32 mm internal diameter. Friction was measured under 1.0 KN of static load. High molecular hyaluronic acid was adapted as a lubricant. Thirty cups were combined with alumina heads and 37 were combined with metal heads. The years cups were in situ was 7.5 (3.2–13.2) for alumina-polyethylene implants and 8.9 (1.5–15.7) for metal-polyethylene implants (p> 0.05).

The revision rate at 15 years follow-up was higher in metal-polyethylene (PE) implants (57%) than that of alumina-PE implants (40%) (p< 0.05). The prevalence of cup loosening was less in alumina-PE implants (12/30) than in metal-PE implants (29/37) (p< 0.01). Less wear was observed in alumina-PE implants (1.15+−0,80mm) than in metal-PE implants (1.62+−0.61mm) (p< 0.01). Less wear was observed in cups without loosening (alumina-PE implants: 1.84+−0.57mm, metal-PE implants: 1.75+−0.51mm) than in those with loosening (alumina-PE implants: 0.69+−0.56mm, metal-PE implants: 1.31+−0.73mm) in both types (alumina-PE implants: p< 0.01, metal-PE implants: p< 0.05). Less wear rate was observed in cups without loosening (alumina-PE implants: 0.11+−0.05 mm/year, metal-PE implants: 0.14+−0.05mm/year) than in those with loosening (alumina-PE implants: 0.17+−0.03 mm/year, metal-PE implants: 0.22+−0.09mm/year) in both types (alumina-PE implants: p< 0.01, metal-PE implants: p< 0.05). The coefficient of friction increased in proportion to the progress of cup wear in both types (alumina-PE implants: r2 =0.217, p< 0.01, metal-PE implants: r2 =0.183, p< 0.01). Relation between the coefficient of friction and stability of implants was not detected in both types, while alumina-PE implants had lower coefficient of friction (0.137+-0.056) than metal-PE implants (0.209+−0.098) (p< 0.01). The torque of metal-PE implants without stem loosening (0.137+−0.053) was larger than that of alumina-PE implants with stem loosening (0.274+−0.088) (p< 0.01).

The results suggest that wear has greater influence on stability of implants than the friction, whereas coefficient of friction increases in worn implants.

A method was developed to take radiographs showing the inner articulation of bipolar hip prostheses. By this method, wear was measured in 68 hips whose inner head diameter was 22 mm. Average annual wear rate was 0.17 mm. Osteolysis was observed in 25 hips (37%) and there was no difference between the annual wear rate of hips with and without osteolysis. Studying 19 retrieved prostheses, abrasion of the rim was deeper in hips with osteolysis than those without it. Wear rate of the inner articulation in bipolar hip prosthesis is much larger than that in Charnley’s prosthesis, as linear penetration into the articulation surface reduces the motion range of the inner articulation and this increases impingement and advances rim abrasion.