Objective: We examined the relationship between isokinetic knee extensor strength and lower limb skeletal muscle mass measured by the impedance method. The objective of this study was to clarify the characteristics of knee extensor strength in patients with osteoarthritis of the knee.
Methods: The osteoarthritis (OA) group was composed of thirty-six lower limbs of twenty females with OA of the knee, and the control group was composed of fifty lower limbs of twenty five healthy females, respectively. The mean age of the OA group was 68.1±4.9 years and that of the control group was 70.3±3.6 years, respectively. We measured lower limb skeletal muscle mass by the eight electrode body impedance analysis (BIA) method. In addition, we measured the peak torque of the knee extensor muscle strength in 60 deg/sec. Investigations were also carried on primary lower limb skeletal muscle mass and knee extensor strength obtained from the control group. We then predicted the knee extension strength of the OA group, which was obtained using a formula.
Results: Lower limb skeletal muscle mass for the OA group was 6.2±0.6 kg, and for the control group was 6.3±0.5 kg (n.s.), respectively. Knee extensor torque for the OA group was 60.0±16.1 Nm, and for the control group was 77.7±13.7 Nm (p < 0.01), respectively. The primary regression equation in the control group was y = 11.016x + 8.63 (r = 0.428). Predictive value of knee extensor strength of the OA group obtained from the regression equation was 77.4±6.7 Nm.
Conclusion: The ratio of muscle output for skeletal muscle mass decreases in the patients with OA. Therefore, we think instead of simply increasing the muscle mass in the rehabilitation of patients with OA, it is necessary to continue to improve the ratio of muscle to muscle mass output.

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Objective: The aim of this study was to assess the efficacy of a full-length lateral wedged insole in combination with an ankle sprain supporter for treatment of osteoarthritis of the knee.
Methods: Thirty seven outpatients were prospectively randomized and treated with a lateral wedged insole alone (the insole alone group, n = 19) or an ankle sprain supporter in combination with an insole (the insole with support group, n = 18) for four weeks.
Results: The Lequesne index remission score was significantly improved in the insole with support group (4.1±4.2 points) compared with the insole alone group (1.3±3.2 points) (P = 0.026). The mean value of correction of the femorotibial angle was higher in the insole with support group (1.1±0.84°) than in the insole alone group (0.74±99°), although the difference between the two groups was not statistically significant.
Conclusion: The full-length lateral wedged insole in combination with an ankle sprain supporter will benefit patients with knee osteoarthritis.

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Objective: Recently, idiopathic osteonecrosis of the knees has been diagnosed at an early stage with magnetic resonance imaging (MRI). Patients who were classified as stage 1 by Koshino's classification (1982) underwent conservative treatments and we measured the MRI and radiographic results of these patients.
Patients and Methods: 17 patients who were treated in our hospital from April 2007 to December 2011, were entered into this study. Patients were aged 46-79 years old (mean age 64.6 years). Five males and 12 females were studied, over the observation period of 6-30 months (mean follow up period 12.8 months). Thirteen patients had pathological changes in the medial femoral condyle, and 4 in the medial tibial plateau, and were all classified as stage 1 by Koshino's classification. These patients underwent conservative treatments and were evaluated with MRI and radiographically.
Results: Magentic resonance imaging revealed that low signal areas in T1-weighted images disappeared in 7 patients (41%). However, 12 patients (71%) showed progression of stage by Koshino's classification. With regard to the Kellgren and Lawrence classification, 12 out of 17 patients (71%) revealed progressive arthritic changes.
Conclusions: Seventeen patients classified as stage 1 by Koshino's classification underwent conservative treatments. It appeared that low signal areas in T1-weighted images disappeared in 7 patients (41%), but 12 patients (71%) arthritic changes were progressive. Although the majority of patients with idiopathic osteonecrosis of the knees were classified as stage 1 of Koshino's classification, they only minimally improved with conservative treatment.

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Objective: Synvisc® is a cross-linked hyaluronan preparation with higher viscosity than existing hyaluronan preparations and with more powerful and longer-lasting analgesic effects. The objective of this study was to evaluate the efficacy and safety of Synvisc® in patients persistently experiencing pain after treatment with an existing hyaluronan preparation (Artz®).
Methods: Subjects included 45 patients (70 knee joints) with osteoarthritis of the knee with persistent pain after treatment with Artz®. Synvisc® was administered three times at weekly intervals. Visual analog scale (VAS) was recorded before treatment and after 1 week, 2 weeks, 3 months and 6 months, respectively. Japanese Orthopedic Association (JOA) score was recorded before treatment and after 6 months. These scores were then analyzed accordingly.
Results: JOA scores improved significantly (from 76.9 to 81.9) after 6 months compared to before treatment. VAS scores during movement improved significantly after 1 week, and continued to improve up to 6 months (from 51.6 to 36.6). However, no significant effect was seen in the severe osteoarthritis group (Kellgren-Lawrence Grade III or IV; 23 patients) or in the group given Artz® for ≥ 1 year (31 patients). One of the 45 Synvisc® patients experienced a local adverse event.
Conclusions: Synvisc® is a useful medication in patients who do not respond adequately to Artz®. Efficacy was low in cases with severe deformation or persistent osteoarthritis, potentially representing a limitation of hyaluronan preparations in general. More local adverse events were seen with Synvisc® than with Artz®. Synvisc® should therefore be used with caution, taking account of the potential risks and benefits.

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Objective: Various factors such as the approach used, position of the patella component (PC), and rotation of the femoral component (FC) affect the postoperative results of total knee arthroplasty (TKA) for the patellofemoral joint (PFJ). In this study, we aimed to clarify the factors involving PFJ pain, lateral tilt of the PC, and lateral displacement (LD) of the PC from preoperative, intraoperative and postoperative measurement values of various factors in daily clinical practice.
Methods: TKA with patellar resurfacing was performed on 129 knees by the same surgeon. The surgical procedure was performed using the medial parapatellar or subvastus approach, and a modified gap technique was used. The observation period was an average of 12.5 months. PFJ pain, the lateral tilt angle, and lateral displacement amount were examined. The values of various factors were measured before, during and after the surgery.
Results: PFJ pain was observed in 15 knees (11.6%). Age (P = 0.024), and difference between LD and PCs (P = 0.030) were significantly related factors. The lateral tilt angle increased 5° or more compared with that immediately after surgery in seven knees (5.4%), whereas it decreased 5° or more in 12 knees (9.3%), respectively. The difference between TD and PCs (P = 0.015) was a significantly related factor. The lateral displacement amount was increased 3 mm or more compared with that immediately after surgery in 12 knees (9.3%), whereas it decreased 3 mm or more in 13 knees (10.1%), respectively. The PC setting position (P = 0.044), and difference between LD and PCs (P = 0.016) were significantly related factors. No relationships were observed between PFJ pain, lateral tilt, and lateral displacement.
Conclusion: For improving the postoperative results of patellar resurfacing, we have performed grasp activity, set the PC with medialization at 10% of the patellar diameter from the patellar center, and selected PCs similar to the patellar diameter.

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Objective: The purpose of this study was to investigate the relationship between the intraoperative joint gap and range of motion in posterior-stabilized (PS) type total knee arthroplasty (TKA) using a navigation system and a spring-loaded tensioner device.
Methods: Study subjects included 31 patients with PS-fix type TKA and 40 patients with PS-mobile type TKA, respectively. Intraoperative joint gap of both medial and lateral sides were measured with the patello-femoral joint reduced at knee flexion angles of 0, 30, 60, 90 and 130 degrees, respectively. Postoperative knee flexion angle was evaluated at one year after surgery.
Results: In the PS-fix type TKA group, the average medial joint gap changes were 2.0, 2.2, 2.4, 0.5, -1.9 and -1.7 mm at each range of motion between 30-0, 60-0, 90-0, 130-0, 130-90, and 130-60 degrees of flexion, respectively. The average postoperative flexion angle was 110.3 degrees. In the PS-mobile type TKA group, the average medial joint gap changes were 1.9, 2.3, 2.5, 1.0, -1.5 and -1.3 mm at each range of motion between 30-0, 60-0, 90-0, 130-0, 130-90, and 130-60 degrees of flexion, respectively. The average postoperative flexion angle was 120.6 degrees, and was significantly greater than the preoperative flexion angle. The medial joint gap change value of 130-90 degrees and 130-60 degrees showed a positive correlation with postoperative knee flexion angle in the PS-fix type TKA group. Conversely, there was no correlation in all pairings between joint gap change value and flexion angle in PS-mobile type TKA group.
Conclusion: In PS-fix type TKA, there is a tendency for large postoperative flexion angle when the intraoperative medial joint gap changes minimally from flexion to deep flexion. Conversely, there are no correlations between joint gap change value and flexion angle in PS-mobile type of TKA. Average postoperative flexion angles are significantly greater than preoperative flexion angles in the PS-mobile type TKA.

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Objective: In order to evaluate the influence of kinematics by two different design concepts of cruciate-retaining total knee arthroplasties (TKAs), we compared intra-operative findings of compressive forces on the tibial joint surface in terminal procedure after assembling each component.
Methods: We developed a tibial metal tray containing six load cells to directly measure compressive forces on the tibio-femoral joint surface. Utilizing both a navigation system and our developed force sensor, 13 NexGen® CR TKAs (Z group) and 9 NRG® CR TKAs (S group) were compared with axial rotation, distribution of six local forces, subtotal forces of lateral/medial tibial compartment and kinematic pathway (gravity axes) which jointed a lateral/medial gravity point to be made by three local forces.
Results: The two groups showed different findings except the axial rotation pattern. Z group's subtotal force had a higher lateral force than the medial force (P < 0.05), but lateral roll back (6 mm) which was similar to medial roll back in the kinematic pathway. These findings indicated an undesirable influence of asymmetric condyle and dual contact design in the NexGen® TKA. Conversely, S group's subtotal force showed a similar lateral force compared to the medial force and internal rotation with medial pivot which indicated a more lateral roll back (7 mm) than medial roll back (4 mm) in the kinematic pathway. These findings support the superiority of single radius and spherical arc design in the NRG® TKA.
   Moreover, well gap balances in Z group were shown at 20° and 110° of knee flexion. Because the spacer block was inserted into the gap spaces between the aspect of the femoral bone cut and the tibial bone cut with 6.5° of posterior slope, this finding indicated that gap balances were not adjusted at full extension and 90° knee flexion, and this led us to observe the gap balance was inclined to laxity of the medial cruciate ligament.
Conclusions: Our developed force sensor showed that two different design concepts of TKAs enable there to be different ligament balance, gap balance and kinematic pathways, except in axial rotation.

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Objectives: The purpose of this study was to investigate changes in pelvic inclination angle (PIA) between the supine position and standing position after total hip arthroplasty (THA), and the correlation between cup position and PIA. Furthermore, we also examined the effects of pelvic tilt on ultra-high molecular weight polyethylene (UHMWPE) liner wear.
Methods: Fifty-three patients who underwent primary cementless THA (68 hips) were included in this study. In all cases, the porous-coated anatomic total hip system (Stryker Howmedica Osteonics, Allendale, NJ) with a conventional UHMWPE liner and a 26-mm cobalt-chromium femoral head were used. We measured PIA, cup inclination and anteversion angle in the supine and standing positions at the final follow-up. Annual polyethylene liner wear rate in the supine position was also measured. We performed multiple regression analysis between the annual polyethylene liner wear rate and the following factors in both positions including age at surgery, gender, PIA, cup inclination and anteversion.
Results: The mean annual polyethylene liner wear rate was 0.24 mm/year. PIA was 24.7° in the supine position, and 31.6° in the standing position (p < 0.01). Cup inclination was 40.2° in the supine position and 41.9° in the standing position (p < 0.01), while cup anteversion was 14.5° in the supine position and 18.2° in the standing position (p < 0.01). Multiple regression analysis revealed that the annual polyethylene linear wear rate was found to increase significantly with increase of cup inclination and PIA in the supine and standing positions. Adjusted R² was 0.09 in supine position and 0.16 in standing position, respectively.
Conclusion: This study has shown that cup inclination and PIA affect the polyethylene wear rate. A comparison of adjusted R² for the supine position and the standing position revealed that cup inclination and PIA in the standing position have a greater influence on polyethylene wear.

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Objective: A low bone quality is a risk factor for fractures independent of the bone mineral density (BMD). Pentosidine and homocysteine are the main bone quality markers used in clinical practice, and the levels of these markers are reported to be high in patients with rheumatoid arthritis (RA) compared to normal controls. It has been shown that biologic agents and methotrexate reduce the serum pentosidine level. However, there have so far been no reports that have compared the homocysteine level, bone metabolic markers and bone mineral density after treatment with biologic agents. The aim of this study was to assess the plasma concentrations of bone quality markers and bone metabolic markers, BMD and disease activity in patients with RA who were receiving biologic agents, and to compare the values to control subjects using other agents.
Methods: Sixty-two patients with RA (9 male, 53 female; median age: 66.5 years) without diabetes mellitus or renal dysfunction were included in this study. Thirty-two of 62 patients received biologic agents. The plasma concentrations of pentosidine, homocysteine, intact P1NP, TRACP-5b, CRP, ESR, and MMP-3 levels, the DAS28-ESR, DAS28-CRP, CDAI, and SDAI scores, and the BMD of the lumbar spine and proximal femur were assessed. We compared these parameters between patients being treated with biologic agents (B group) and those being treated with other agents (N group). The relationships between disease activity and bone quality markers were examined.
Results: The CDAI, SDAI, CRP, and MMP-3 were significantly lower in the B group than the N group (p < 0.05). The BMD, intact P1NP and TRACP-5b levels showed no significant differences between the two groups. However, the levels of pentosidine were significantly lower in the B group than the N group (p < 0.05). The pentosidine level was significantly correlated with ESR, DAS28-ESR, CDAI, and SDAI, and the homocysteine level was significantly correlated with DAS28-CRP, respectively.
Conclusion: In this study, the BMD and bone metabolic markers showed no significant differences between the patients with RA being treated with biologic agents and those who were being treated with other agents. However, the levels of bone quality markers were significantly lower in the group treated with biologic agents. These results suggest that biologic therapy can improve not only disease activity, but also the bone quality in patients with RA.

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Objective: Methotrexate (MTX) is considered as an anchor drug in the treatment of rheumatoid arthritis (RA) and the importance of dose incrementation has also become more apparent in Japan since 2011. This study assesses the effects and safety of MTX at a dose of > 8 mg/week in patients with RA.
Methods: Among 199 patients with RA treated with MTX, we examined 35 of them who were prescribed a dose > 8 mg/week, between January 2011 and June 2012 inclusive. Blood values, DAS28 CRP, adverse events and concomitant drug use were analyzed before and at the time of the last observation, an average of 11 months after increasing the dose of MTX.
Results: Seventeen patients were concurrently taking biologic agents in addition to MTX. The maximum average dose used in this patient population was 11.0 mg/week (range: 10 mg to 14 mg/week). The reason for increasing the MTX dose included: poor control of RA, a need to decrease corticosteroid use, and discontinuing biologic agents due to economic or other reasons. The average DAS28 values significantly improved from 2.88 to 2.18, respectively, from prior to the dose increase, and at the time of the last observation. Over half of the patients responded according to the European League Against Rheumatism (EULAR) response criteria. Adverse events included three cases. One case was with interstitial pneumonia, another one was mycoplasma pneumonia and the other was stomatitis. Liver damage that occurred in five patients improved in one case by decreasing the dose of MTX and by adding or increasing the dose of folic acid in four cases, respectively. Cytopenias were not apparent in this study population.
Conclusion: Increasing the dose of MTX decreased the disease activity of RA in our study population. Although some patients developed side effects related to increased MTX doses, these were clinically tolerable.

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Objective: The purpose of this study was to clarify the incidence and the risk factors of preoperative deep venous thrombosis (DVT) in patients with hip fracture (HF) and to evaluate the efficacy in reducing DVT with the mechanical thromboprophylaxis alone, including compression stockings and/or intermittent pneumatic compression devices (IPC).
Methods: A retrospective chart review was conducted on 162 patients (33 men and 129 women, mean age 82.5 years old) admitted to our institution with HF in 2011. All patients wore a compression stocking during the hospital stay, and underwent duplex ultrasonography (US) to rule out DVT before surgery. Patients without preoperative DVT (non-DVT group) were treated with IPC for two days postoperatively. Patients with preoperative proximal DVT (DVT group) were treated with inferior vena cava filter insertion before surgery. The differences between the groups were tested for statistical significance using the Chi square test, the unpaired t-test, and logistic regression analysis. Statistical significance was defined as p < 0.05. All statistical analyses were performed using an SPSS ver.19 (SPSS Inc., Chicago, IL).
Results: Preoperative DVT was diagnosed in 28 patients (17.3%). Patients with femoral neck fracture were at a higher risk of developing DVT compared to patients with femoral trochanteric fractures (p = 0.039). The DVT group (7.29±3.48 days) showed a significant difference compared to the non-DVT group (6.01±3.11 days) in delayed length from the time of injury until the time of surgery (p = 0.050). The DVT group required more blood transfusion postoperatively than the non-DVT group (p = 0.026). Hemoglobin values at one week postoperatively were significantly lower in the DVT group (9.37±1.38 g/dl) than the non-DVT group (9.95±1.35 g/dl) (p = 0.035). Although one patient (0.6%) developed symptomatic DVT after surgery, there was no patient (0%) who suffered from pulmonary embolism.
Conclusion: HF patients are susceptible to dehydration, and therefore they are at a higher risk of developing preoperative DVT. We recommend the routine use of mechanical thromboprophylaxis immediately after admission to prevent development of DVT, and for patients to undergo compression ultrasonography to rule out DVT in all the patients before delayed surgery exceeding more than 3 days.

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Objective: The ability of bacteria to adhere to the surface of biomaterials is a pivotal event in the pathogenesis of implant-related infections. In this in vitro study, we evaluated the adherence ability of Staphylococcus epidermidis (S. epidermidis) (ATCC35984) to the surface of solid biomaterials, such as oxidized zirconium-niobium alloy (OXINIUM), cobalt-chrome alloy (CoCrMo), titanium alloy (Ti6Al4V), commercially pure titanium (cp-Ti), and stainless steel (SUS), respectively.
Methods: The surface roughness and wettability (water contact angles) of test specimens were analyzed, and viable adherent bacterial density was quantitatively determined (n = 10).
Results: Three-dimensional measuring via a laser microscope revealed featureless and smooth surfaces in all specimens (Ra < 10 nm). The mean value of S. epidermidis adherence to CoCrMo (9.7×10⁵ cfu/ml) was significantly lower than that compared to Ti6Al4V (15.8×10⁵ cfu/ml), cp-Ti (16.3×10⁵ cfu/ml), or SUS (15.4×10⁵ cfu/ml) (P < 0.05), respectively.
Conclusion: These results indicate that CoCrMo, which has a smooth and hydrophobic surface, is less susceptible to bacterial adherence and is less inclined to develop infection under a similar degree of roughness than the other materials.

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We report the case of a patient with rheumatoid arthritis who developed Listeria monocytogenes septic arthritis affecting her total knee arthroplasty during treatment with etanercept. The patient was a 66-year-old female who had suffered from rheumatoid arthritis for 18 years and was treated with etanercept, methotrexate, and prednisolone. After five days from the last etanercept injection, there was acute painful swelling of her left knee joint. In view of hypotension and high fever she was treated for suspected septic shock with intravenous ampicillin 8 grams total daily dose and fluid resuscitation. About 100 ml of moderately cloudy inflammatory synovial fluid was aspirated and Listeria monocytogenes sensitive to ampicillin was grown on culture. After recovery, all prostheses of the left knee were removed, and cement spacers containing vancomycin were inserted. Several hydroxyapatite blocks containing vancomycin were embedded in the cement spacers to maintain sustained-release of the antibiotic. After 3 months from the implant removal, a revision of total knee arthroplasty was performed. During the operation, no infection was identified by means of intraoperative real-time polymerase chain reaction (PCR) and subsequent histopathology findings. The patient recovered and regained mobility on her left knee joint. No infectious symptoms were observed at 1 year after revision of the total knee arthroplasty.

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