Comparison of short-term clinical outcomes between open-wedge high tibial osteotomy and tibial condylar valgus osteotomy.

BACKGROUND: This study aimed to compare radiological features and short-term clinical outcomes between open-wedge high tibial osteotomy (OWHTO) and tibial condylar valgus osteotomy (TCVO), to provide information facilitating decision-making regarding those two procedures. METHODS: Twenty-seven cases involving 30 knees that had undergone OWHTO (HTO group) and eighteen cases involving 19 knees that had undergone TCVO (TCVO group) for medial compartment knee osteoarthritis (OA) were retrospectively evaluated. Patient characteristics, severity of knee OA, lower limb alignment, joint congruity and instability were measured from standing full-length leg and knee radiographs obtained before and 1 year after surgery. Range of motion in the knee joint was measured and Knee Injury and Osteoarthritis Outcome Score (KOOS) was obtained to evaluate clinical results preoperatively and 1 year postoperatively. RESULTS: Mean age was significantly higher in the TCVO group than in the HTO group. Radiological features in the TCVO group included greater frequencies of advanced knee OA, varus lower limb malalignment, higher joint line convergence angle, and varus-valgus joint instability compared to the HTO group before surgery. However, alignment of the lower limb and joint instability improved to comparable levels after surgery in both groups. Maximum flexion angles were significantly lower in the TCVO group than in the HTO group both pre- and postoperatively. Mean values in all KOOS subscales recovered similarly after surgery in both groups, although postoperative scores on three subscales (Symptom, Pain, and ADL) were lower in the TCVO group (Symptom: HTO, 79.0; TCVO, 67.5; Pain: HTO, 80.5; TCVO, 71.1; ADL: HTO, 86.9; TCVO, 78.0). CONCLUSIONS: Both osteotomy procedures improved short-term clinical outcomes postoperatively. TCVO appears preferable in cases of advanced knee OA with incongruity and high varus-valgus joint instability. An appropriate choice of osteotomy procedure is important to obtain favorable clinical outcomes.

High risk of elevated metal concentrations with 9/10-mm stem trunnions and highly cross-linked polyethylene grafted with poly(2-methacryloyloxyethyl phosphorylcholine) in total hip arthroplasty.

BACKGROUND: The risks of metal release due to fretting and corrosion at the head-neck junction and consequent adverse local tissue reaction (ALTR) have concerns in metal-on-polyethylene (MoP) total hip arthroplasty (THA). Although trunnions have become thinner in diameter to increase the range of motion, it has remained unclear whether this change affects metal release and ALTR in vivo. This study aimed to investigate serum metal concentrations and the prevalence of ALTR in MoP THA with a 9/10-mm stem trunnion. PATIENTS AND METHODS: A consecutive series of 37 hips that underwent THA using MoP grafted with poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) with a 9/10-mm trunnion stem were retrospectively reviewed. Serum metal levels were assessed and compared with those in MoP THA with a 10/12-mm trunnion stem. ALTR was diagnosed with serum metal levels and cross-sectional images. The factors associated with serum metal levels were also assessed. RESULTS: The median serum cobalt and chromium levels were 1.5 µg/L and 1.0 µg/L in the 9/10-mm group and 0.2 µg/L and 0.4 µg/L in the 10/12-mm group, respectively. ALTR was found in 5 hips of 3 patients. Revision surgery was performed in 4 hips, and all stem trunnions and femoral heads showed severe corrosion. Postoperative walking ability was associated with serum metal levels. CONCLUSION: It was found that a 9/10-mm stem trunnion with MoP grafted with PMPC had high risks of metal release in primary THA. Careful follow-up and cross-sectional imaging are needed to detect ALTR for early revision.

Cortical thickness mapping at segmented regions in the distal radius using HR-pQCT.

INTRODUCTION: An advanced method of analyzing the cortical bone microarchitecture of the distal radius using high-resolution peripheral quantitative computed tomography (HR-pQCT) was developed. MATERIALS AND METHODS: The subjects were 60 women (20: aged 30-49, 20: aged 50-69, and 20: aged 70-89 years). The distal radius was scanned by HR-pQCT, and its cortical volumetric bone mineral density (Ct.vBMD), cortical porosity (Ct.Po), and cortical thickness (Ct.Th) were measured. The cortical bone was also divided into three areas according to whether its thickness was < 0.5 mm, 0.5-1.0 mm, or > 1.0 mm, and the percentage of each surface area in the total surface area of cortical bone was calculated (Ct.Th (<0.5), Ct.Th (0.5-1.0), Ct.Th (>1.0), respectively). The cortical bone at the distal radius was further segmented into dorsal, palmar, radial, and ulnar sides, and the above-described parameters were measured in these regions. RESULTS: Integral analysis showed that Ct.vBMD and Ct.Th decreased and Ct.Po increased with age (R = - 0.62, - 0.55, and 0.54). Ct.Th (< 0.5) expanded with age (R = 0.49), with the rate of change between those aged 30-49 years and those aged 50-69 years being 106.7%. On regional analysis, the expansion of Ct.Th (< 0.5) with age was particularly marked on the dorsal and palmar side (R = 0.51 and 0.49), where the rate of change between those aged 30-49 years and those aged 50-69 years was the highest, at 196.1 and 149.6%. CONCLUSION: The method to identify areas of cortical bone thinning in the segmented regions of the dorsal, palmar, radial, and ulnar sides of the distal radius using HR-pQCT may offer a sensitive assessment of age-related deterioration of cortical bone.

Computed tomographic evaluation of three types of screw trajectories for posterior cervical spine fixation: Cervical pedicle screw, lateral mass screw, and paravertebral foramen screw.

Computed tomography (CT) attenuation values of cervical spine were evaluated in vivo using a clinically relevant group. To compare CT attenuation values between cervical pedicle screw (CPS), lateral mass screw (LMS), and paravertebral foramen screw (PVFS) trajectories. CPS and LMS are commonly used for posterior fixation of the cervical spine. The PVFS method has been reported as a new method. CT attenuation values along the screw trajectory are reportedly associated with screw stability. We identified 45 patients who had undergone whole-body CT for trauma with no injury to the cervical spine. Regions of interest (ROIs) were designated along the trajectories that would be used for CPS, LMS, and PVFS through vertebral pedicles and lateral masses of the C3-C6 vertebrae. CT attenuation values of each ROI were measured and compared between each screw trajectories at each cervical vertebral level. Participants were divided into Group I (age, 20-39 years; n = 12), Group II (age, 40-59 years; n = 17), and Group III (age, 60-79 years; n = 16). CT attenuation values of ROIs were compared between each age group. PVFS trajectories showed higher CT attenuation values than LMS trajectories at every vertebral level and also higher values than CPS trajectories at C5 and C6 levels. CT attenuation values at C3 were lower than those at C4 in the LMS trajectory and lower than those at C5 and C6 in the PVFS trajectory. CT attenuation values were lower in the elder group (>60 years old) than in the other 2 groups for all screw trajectories. CT attenuation values suggested that the PVFS technique may be useful for posterior fixation of the cervical spine in elder patients who require more secure fixation.

Relationships between QUS and HR-pQCT, DXA, and bone turnover markers.

INTRODUCTION: Relationship of quantitative ultrasound (QUS) with high-resolution peripheral quantitative computed tomography (HR-pQCT), dual-energy X-ray absorptiometry (DXA), and bone-related biochemical markers was analyzed. MATERIALS AND METHODS: The subjects were 480 individuals. Speed of sound (SOS) was measured by calcaneal QUS. Volumetric bone mineral density (vBMD) and microarchitecture of trabecular and cortical bone in the distal radius and tibia were assessed by HR-pQCT. Areal bone mineral density (aBMD) in the lumbar spine and proximal femur were measured by DXA. TRACP-5b, P1NP, 25 (OH) vitamin D, and pentosidine were evaluated by biochemical tests. The correlation of each parameter was analyzed for all subjects and by sex and age group. RESULTS: QUS was moderately correlated with Tb.vBMD and Tb.BV/TV in the radius and tibia. No correlation was seen with Ct.vBMD or cortical porosity (Ct.Po). Although a correlation was seen with cortical thickness (Ct.Th) in the tibia in all subjects, no correlation was seen in women aged ≥ 60 years. QUS showed moderate correlations with aBMD in the proximal femur. Although moderate correlation was seen with aBMD in the lumbar spine in all subjects, no correlation was seen in subjects aged ≥ 60 years. No significant correlations were seen between QUS and biochemical markers. CONCLUSIONS: Moderate correlations were seen between QUS and Tb.vBMD and microarchitecture in the radius and tibia and aBMD of the proximal femur. On the other hand, practically no correlations were seen with Ct.vBMD or Ct.Po and the bone-related biochemical markers. Only in middle age, moderate correlations were seen with Ct.Th in the tibia and with aBMD of the lumbar spine.

Tibial Condylar Valgus Osteotomy Combined With Medial Open-Wedge Distal Tuberosity Tibial Osteotomy.

Severe varus deformity in osteoarthritic knees is attributed not only to bony deformity but also to intra-articular deformity as a result of medial joint space narrowing with lateral joint space widening (increased joint line convergence angle). In such knees, correction of bony deformity by high tibial osteotomy (HTO) alone may not be capable of restoring physiological joint geometry and biomechanics. Tibial condylar valgus osteotomy (TCVO), an L-shaped osteotomy in the medial tibial condyle, has been proposed to improve articular stability and congruity by elevating the medial tibial joint line and addressing the articular component of the deformity; however, its surgical efficacy for correction of the valgus deformity is limited. Therefore a procedure combining HTO and TCVO can be a reasonable option to achieve restoration of the knee joint physiology in such situations. In our current practice, medial open-wedge distal tuberosity tibial osteotomy (MOW-DTO) has been the procedure of primary option among the HTO procedures to avoid patellofemoral overload which could be an inherent problem in medial open-wedge HTO. In this article, the surgical rationale and the combined procedure of TCVO and MOW-DTO are described.

Analysis of bone erosions in rheumatoid arthritis using HR-pQCT: Development of a measurement algorithm and assessment of longitudinal changes.

PURPOSE: The purpose of this study was to establish an algorithm for measuring bone erosions at metacarpophalangeal (MCP) joints using high-resolution peripheral quantitative computed tomography (HR-pQCT), to investigate the precision of measurements, and to assess longitudinal changes in bone erosions among patients with rheumatoid arthritis (RA). METHODS: The 2nd and 3rd MCP joints were scanned at a voxel size of 60.7 µm using second-generation HR-pQCT. Bone erosions on MCP joints were identified using a semi-automated algorithm we developed, and each erosion parameter was measured. Measurement reproducibility was evaluated in 19 healthy subjects using intraclass correlation coefficients (ICCs) and root mean square percent coefficient of variance (RMS%CV). Finally, longitudinal changes in bone erosions over a period of 12 months were assessed in 26 patients with RA based on the calculated least significant change (LSC). RESULTS: Reproducibilities for measurement parameters regarding bone erosions with our algorithm were good (all ICCs ≥ 0.98; all RMS%CVs < 5%). No erosion parameters showed significant changes after 12 months of treatment in terms of median values in all erosions, while both progression and repair of erosions were observed individually (e.g., erosion volume: progression, 26% (+0.62 mm3); repair, 34% (-0.85 mm3); no change, 40%). CONCLUSIONS: The measurement algorithm developed for bone erosions at MCP joints showed good reproducibility. Both progression and repair of bone erosions were observed in patients with RA even after 12 months of appropriate treatment. Our algorithm may be useful to investigate the etiology of RA and assess drug efficacy.

Randomized controlled trial of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate in patients with postmenopausal osteoporosis: The TERABIT study.

PURPOSE: The effects of daily teriparatide (20 µg) (D-PTH), weekly high-dose teriparatide (56.5 µg) (W-PTH), or bisphosphonates (BPs) on areal bone mineral density (aBMD), bone turnover markers (BTMs), volumetric BMD (vBMD), microarchitecture, and estimated strength were investigated in postmenopausal osteoporosis patients. METHODS: The study participants were 131 women with a history of fragility fractures. They were randomized to receive D-PTH, W-PTH, or BPs (alendronate or risedronate) for 18 months. Dual-energy X-ray absorptiometry (DXA), BTMs, and high-resolution peripheral quantitative CT (HR-pQCT) parameters were evaluated at baseline and after 6 and 18 months of treatment. The primary endpoint was the change (%) in cortical thickness (Ct.Th) after 18 months' treatment compared with baseline. RESULTS: DXA showed that D-PTH, W-PTH, and BPs increased lumbar spine aBMD (+12.0%, +8.5%, and +6.8%) and total hip aBMD (+3.0%, +2.1%, and +3.0%), but D-PTH and W-PTH decreased 1/3 radius aBMD (-4.1%, -3.0%, -1.4%) after 18 months. On HR-pQCT, D-PTH increased trabecular vBMD (Tb.vBMD) at the distal radius and tibia after 18 months (+6.4%, +3.7%) compared with the BPs group, decreased cortical volumetric tissue mineral density (Ct.vTMD) (-1.8%, -0.9%) compared with the other groups, increased Ct.Th (+1.3%, +3.9%), and increased failure load (FL) (+4.7%, +4.4%). W-PTH increased Tb.vBMD (+5.3%, +1.9%), maintained Ct.vTMD (-0.7%, +0.2%) compared with D-PTH, increased Ct.Th (+0.6%, +3.6%), and increased FL (+4.9%, +4.5%). The BPs increased Tb.vBMD only in the radius (+2.0%, +0.2%), maintained Ct.vTMD (-0.6%, +0.3%), increased Ct.Th (+0.5%, +3.4%), and increased FL (+3.9%, +2.8%). CONCLUSIONS: D-PTH and W-PTH comparably increased Ct.Th, the primary endpoint. D-PTH had a strong effect on trabecular bone. Although D-PTH decreased Ct.vTMD, it increased Ct.Th and total bone strength. W-PTH had a moderate effect on trabecular bone, maintained Ct.vTMD, and increased Ct.Th and total bone strength to the same extent as D-PTH.

Differences in the flexion and extension phases during kneeling investigated by kinematic and contact point analyses: a cross-sectional study.

BACKGROUND: Kneeling is necessary for certain religious and ceremonial occasions, crouching work, and gardening, which many people take part in worldwide. However, there have been few reports about kneeling activities. The purpose of this study was to clarify the kinematics of kneeling. METHODS: The subjects were 15 healthy young males. Kneeling activity was analysed within a knee flexion angle from 100° to maximum flexion (maxflex, mean ± SD = 161.3 ± 3.2°). The kinematic and contact point (CP) analyses were performed using a 2D/3D registration method, in which a 3D bone model created from computed tomography images was matched to knee lateral fluoroscopic images and analysed on a personal computer. RESULTS: In the kinematic analysis, the femur translated 37.5 mm posteriorly and rotated 19.8° externally relative to the tibia during the knee flexion phase. During the knee extension phase, the femur translated 36.4 mm anteriorly, which was almost the same amount as in the knee flexion phase. However, the femur rotated only 7.4° internally during the knee extension phase. In the CP analysis, the amount of anterior translation of the CP in the knee extension phase was greater in the medial CP and smaller in the lateral CP than that of posterior translation in the knee flexion phase. CONCLUSIONS: In kneeling, there was a difference in the rotational kinematics between the flexion phase and the extension phase. The kinematic difference between the flexion and extension phases may have some effect on the meniscus and articular cartilage.

Bone microstructure in healthy men measured by HR-pQCT: Age-related changes and their relationships with DXA parameters and biochemical markers.

OBJECTIVE: The primary purpose of this cross-sectional study was to investigate the characteristics of age-related changes in bone microstructure on high-resolution peripheral quantitative computed tomography (HR-pQCT), areal bone mineral density (aBMD) on dual-energy X-ray absorptiometry (DXA), and bone-related biochemical markers in men. The secondary purpose of this study was to examine how bone microstructure is related to aBMD and biochemical markers. METHODS: The subjects were 128 healthy Japanese men (20-97 years old). Bone microstructure was measured in the distal radius and tibia using second-generation HR-pQCT; aBMD in the proximal femur and lumbar spine was measured with DXA; and tartrate-resistant acid phosphatase-5b (TRACP-5b), type I procollagen-N-propeptide (P1NP), 25(OH) vitamin D, and pentosidine concentrations were measured by blood tests. RESULTS: In trabecular bone, the trabecular volumetric BMD (Tb.vBMD) and trabecular number (Tb.N) were lower with age (r = -0.23, -0.35) (r = -0.36,-0.33), and trabecular separation (Tb.Sp) and the star volume of marrow space (V*ms) were higher with age (r = 0.29, 0.41) (r = 0.34, 0.38) in both the radius and tibia. In cortical bone, cortical volumetric BMD (Ct.vBMD) was lower with age (r = -0.25, -0.52), and cortical porosity (Ct.Po) was higher with age (r = 0.67, 0.62) in both the radius and tibia. In the tibia, cortical thickness (Ct.Th) and cortical area (Ct.Ar) were lower with age (r = -0.40) (r = -0.43), whereas, in the radius, they were maintained, and periosteal perimeter (Ct.Pm) was higher with age (r = 0.35). aBMD in the proximal femur and P1NP were lower, and pentosidine was higher with increased age, whereas aBMD in the lumbar spine, TRACP-5b, and 25(OH) vitamin D had no relationships with age. DXA and HR-pQCT showed strong correlations particularly with femoral aBMD and tibial Tb.vBMD and Ct.Ar (r = 0.61) (r = 0.61), whereas no DXA parameters were related with Ct.Po. In correlations between biochemical markers and HR-pQCT, TRACP-5b and total P1NP were negatively correlated with Ct.vBMD (r = -0.31) (r = -0.35), but almost no other correlations were seen. CONCLUSIONS: Age-related changes of the bone microstructure in men were characterized by decreases in trabecular and cortical vBMD associated with decreased trabecular number, cavitation of the trabecular structure, and increased cortical porosity. Femoral aBMD was strongly related to bone microstructure in the tibia, whereas both lumbar aBMD and femoral aBMD were not related to Ct.Po, and biochemical markers showed almost no relationships with bone microstructure.

Visualization of Airborne Particles as a Risk for Microbial Contamination in Orthopedic Surgery.

Background: The operating theater is recognized to involve a high frequency of occupational blood and body fluid contacts. Objectives: This study aimed to visualize the production of blood and body fluid airborne particles by surgical procedures and to investigate risks of microbial contamination of the conjunctival membranes of surgical staff during orthopedic operations. Methods: Two physicians simulated total knee arthroplasty (TKA) and total hip arthroplasty (THA) in a bio-clean theater using model bones. The generation and behaviors of airborne particles were filmed using a fine particle visualization system, and numbers of airborne particles per 2.83 L of air were counted at the height of the operating and instrument tables. Each action was repeated five times, and particle counts were evaluated statistically. Results: Numerous airborne particles were dispersed to higher and wider areas while "cutting bones in TKA" and "striking and driving the cup component on the pelvic bone in THA" compared to other surgical procedures. The highest particle counts were detected while "cutting bones in TKA" under unidirectional laminar air flow. Discussion: These results provide a clearer image of the dispersion and distribution of airborne particles and identified higher-risk surgical procedures for microbial contamination of the conjunctival membranes. Surgical staff including surgeons, nurses, anesthesiologists, and visitors, should pay attention to and take measures against occupational infection particularly in high-risk surgical situations.

Incidence of and risk factors for hip fracture in Nagasaki, Japan from 2005 to 2014.

The annual incidence of new hip fractures increased from 2005 to 2014 in Nagasaki and females were much more affected. High-risk factors were identified as age ≥ 80 years, winter, indoors, living room, Monday, and early morning. Seven days after admission, most patients remained hospitalized and had been treated surgically. INTRODUCTION: Hip fractures are major osteoporotic fractures that reduce quality of life. In Japan, the incidence of hip fractures increased steadily from 1986 to 2014 and the number of hip fractures could be 7.3-21.3 million by 2050. This study aimed to determine the incidence of hip fractures from 2005 to 2014 in Nagasaki Prefecture and to analyze the characteristics of and risk factors for hip fracture. METHODS: Hip fractures that occurred in Nagasaki Prefecture between 2005 and 2014 were analyzed using emergency transportation records. Fracture type, age, sex, location in which fracture occurred, and risk factors for hip fracture were clarified. RESULTS: The total number of new hip fractures among individuals ≥ 35 years old was 17,395 (mean age, 82.6 years old) and the annual incidence per 100,000 population increased from 147.9 in 2005 to 235.0 in 2014. Females (79.6%) were much more commonly affected than males (20.4%) and cervical fractures were more common than trochanteric fractures in all age groups. Hip fracture tended to be associated with age ≥ 80 years, winter rather than summer, indoors rather than outdoors, and living room rather than the bathroom or toilet. Other high-risk factors were Monday as day of the week, and early morning as the time of day. Seven days after admission, 97.3% of patients were hospitalized and 78.1% of hip fractures had been treated surgically. CONCLUSION: Information on actual situations and valid preventive measures relevant to hip fracture are urgently needed.

Hoxa10 mediates positional memory to govern stem cell function in adult skeletal muscle.

Muscle stem cells (satellite cells) are distributed throughout the body and have heterogeneous properties among muscles. However, functional topographical genes in satellite cells of adult muscle remain unidentified. Here, we show that expression of Homeobox-A (Hox-A) cluster genes accompanied with DNA hypermethylation of the Hox-A locus was robustly maintained in both somite-derived muscles and their associated satellite cells in adult mice, which recapitulates their embryonic origin. Somite-derived satellite cells were clearly separated from cells derived from cranial mesoderm in Hoxa10 expression. Hoxa10 inactivation led to genomic instability and mitotic catastrophe in somite-derived satellite cells in mice and human. Satellite cell-specific Hoxa10 ablation in mice resulted in a decline in the regenerative ability of somite-derived muscles, which were unobserved in cranial mesoderm-derived muscles. Thus, our results show that Hox gene expression profiles instill the embryonic history in satellite cells as positional memory, potentially modulating region-specific pathophysiology in adult muscles.

Differences in bone mineral density and morphometry measurements by fixed versus relative offset methods in high-resolution peripheral quantitative computed tomography.

INTRODUCTION: High-resolution peripheral quantitative computed tomography (HR-pQCT), which enables in vivo analysis of bone morphometry, is widely used in osteoporosis research. The scan position is usually determined by the fixed offset method; however, there are concerns that the scan position can become relatively proximal if limb length is short. The present study compared bone mineral density and morphometry measured using the fixed and relative offset methods, in which the scan position is determined based on the lengths of the forearm and lower leg, and investigated factors responsible for measurement differences between the two methods. METHODS: A total of 150 healthy Japanese subjects, comprising 75 men and 75 women, with a mean age of 45.1 years, were enrolled in this study. The distal radius and tibia were scanned using the fixed and relative offset methods; the fixed offset method involved scanning the radius and tibia at 9 mm and 22 mm, respectively, proximal to their distal articular surfaces. By contrast, the relative offset method entailed scanning the radius at 4% of the forearm length and the tibia at 7.3% of the lower leg length, proximal to their respective distal articular surfaces. The percent overlap between the scan positions of the two methods was measured using the scout views. Measurement values obtained with the two methods were compared. The correlation between the differences in the values among the two methods and forearm length, lower leg length, and body height was examined. RESULTS: The subjects had a mean height of 164.3 ± 14.3 cm, mean forearm length of 252.9 ± 17.3 mm, and mean lower leg length of 346.7 ± 22.3 mm. The mean percent overlap was 85.0 ± 9.1% (59.2-99.6%) for the radius and 79.8 ± 12.5% (48.3-99.8%) for the tibia. Fixed offset scanning yielded higher total volumetric bone mineral density (Tt.vBMD) and cortical vBMD (Ct.vBMD) and greater cortical thickness (Ct.Th) (all p < 0.001). The differences between the two methods in terms of Tt.vBMD, Ct.vBMD and Ct.Th were significantly greater with shorter forearm length, lower leg length, and body height (radius: 0.51 < |r| < 0.63, tibia: 0.61 < |r| < 0.95). CONCLUSION: Measurements of bone mineral density and morphometry obtained using the fixed offset method differed from those obtained using the relative offset method, which takes body size into account. Shorter body height, forearm length, and lower leg length were found to correlate with greater measurement differences. In populations with smaller stature, use of the fixed offset method results in relatively proximal images; thus, caution should be exercised when comparing groups of different height.

A new double level osteotomy procedure to restore a joint line and joint angles in severe varus osteoarthritis. - Double level osteotomy associated with tibial condylar valgus osteotomy (DLOTO).

High tibial valgus osteotomy (HTO) is a well-established surgical procedure to correct a varus malalignment and treat medial compartment osteoarthritis. Recently, double level osteotomy (DLO) was recommended for extensive varus knees as a single level osteotomy (SLO) approach may create an excessive joint line obliquity and eventually result in a new bony deformity. However, a severe varus knee in cases of advanced osteoarthritis involves not only a bony deformity (extra-articular deformity) but also a medial joint space narrowing with a widened lateral joint space (intra-articular deformity). A DLO alone cannot reduce this intra-articular deformity. However, tibial condylar valgus osteotomy (TCVO) can complement DLO as to reduce this intra-articular deformity. This technical note describes a novel modified DLO procedure associated with TCVO which can restore a normal alignment and a joint line and achieve joint preservation even in cases of extensive varus osteoarthritis.

Effects of monthly intravenous ibandronate on bone mineral density and microstructure in patients with primary osteoporosis after teriparatide treatment: The MONUMENT study.

PURPOSE: To investigate the effects of sequential therapy with monthly intravenous ibandronate on bone mineral density (BMD) and microstructure in patients with primary osteoporosis who received teriparatide treatment. METHODS: Sixty-six patients with primary osteoporosis who had undergone teriparatide treatment for more than 12 months (mean 18.6 months) received sequential therapy with 1 mg/month intravenous ibandronate for 12 months. The patients were evaluated using dual-energy X-ray absorptiometry (DXA), quantitative ultrasound, bone turnover markers, and high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline and 6 and 12 months after beginning administration. RESULTS: At 12 months after beginning sequential therapy, the bone resorption marker, tartrate-resistant acid phosphatase-5b, decreased by 39.5%, with 82.3% of the patients exhibiting levels within the normal limit. DXA revealed that the BMD of the lumbar spine increased by 3.2%, with 79.0% of the patients exhibiting a response, and 40.3% experiencing an increase in BMD over 5%. HR-pQCT revealed that the cortical thickness of the distal tibia was increased by 2.6%. The cortical area increased by 2.5%, and the buckling ratio (an index of cortical instability) decreased by 2.5%. Most parameters of the trabecular bone showed no significant changes. These changes in the cortical bone were observed in both the distal radius and tibia and appeared beginning 6 months after treatment initiation. CONCLUSIONS: Sequential therapy with monthly intravenous ibandronate increased the BMD and improved the cortical bone microstructure of osteoporotic patients who had undergone teriparatide treatment.

Precision of 3D Registration Analysis for Longitudinal Study of Second-Generation HR-pQCT.

OBJECTIVE: The objective of this research was to develop 3D registration analysis method in longitudinal studies of high-resolution peripheral quantitative computed tomography (HR-pQCT), to analyze ranges of bone microstructure parameters in addition to standard parameters, and to test the precision of these measurements. METHODS: Scans of HR-pQCT and analysis of bone microstructure were performed at 3 times in 15 subjects. The 3 images were matched 3-dimensionally, and bone microstructures were analyzed in the common region. In addition to standard measurement parameters of geometry, bone mineral density (BMD), trabecular bone, and cortical bone, parameters showing plate to rod-like structure, connectivity, cavity formation of trabecular bone, and bending stability of cortical bone were also measured. Precision was evaluated with the root mean square percent coefficient variance (RMS%CV). RESULTS: RMS%CV was 0.1%-1.3% for geometry, 0.6%-1.9% for BMD, 0.8%-3.3% for trabecular bone, 2.1%-9.8% for additionally measured trabecular bone, 1.0%-3.4% for cortical bone excluding Ct.Po, 6.0%-6.1% for Ct.Po, and 0.8%-1.5% for additionally measured cortical bone. Precision was higher for 3D registration than for 2D registration in geometry, BV/TV, and Ct.Po. CONCLUSIONS: 3D registration analysis of a range of bone microstructural parameters in longitudinal analysis of HR-pQCT showed good precision, offering potential for contributing to future research on osteoporosis and bone metabolic diseases.

A Modified Pre-plating Method for High-Yield and High-Purity Muscle Stem Cell Isolation From Human/Mouse Skeletal Muscle Tissues.

Primary culture of skeletal muscle stem cells (MuSCs) is indispensable to study the dynamics of muscle regeneration and homeostasis. Here we describe the modified pre-plating method for isolating MuSCs in culture with greatly improved purity, yield, and procedure time. The protocol is based on the distinct adhesion characteristics of MuSCs. We reduced the procedure time to 2.5 days to obtain highly purified MuSCs through a newly employed re-plating step, which repeats incubation and cell-suspension. The re-plating step efficiently traps remaining fibroblastic cells, but not MuSCs, on a collagen-coated dish. Additionally, we confirmed that MuSCs can be isolated from small amounts of human/mouse muscle tissues, enabling us to perform experiments with amount-limited specimens. Thus, our method can be performed with basic laboratory equipment suitable for most facilities and without sophisticated MuSC handling techniques.

Deterioration of bone microstructure by aging and menopause in Japanese healthy women: analysis by HR-pQCT.

INTRODUCTION: Second-generation high-resolution peripheral quantitative computed tomography (HR-pQCT) has provide higher quality of bone images with a voxel size of 61 µm, enabling direct measurements of trabecular thickness. In addition to the standard parameters, the non-metric trabecular parameters such as trabecular morphology (plate to rod-like structures), connectivity, and anisotropy can also be analyzed. The purpose of this study is to investigate deterioration of bone microstructure in healthy Japanese women by measuring standard and non-metric parameters using HR-pQCT. MATERIALS AND METHODS: Study participants were 61 healthy Japanese women (31-70 years). The distal radius and tibia were scanned using second-generation HR-pQCT, and microstructures of trabecular and cortical bone were measured. Non-metric trabecular parameters included structure model index (SMI), trabecular bone pattern factor (TBPf), connectivity density (Conn.D), number of nodes (N.Nd/TV), degree of anisotropy (DA), and star volume of marrow space (V*ms). Estimated bone strength was evaluated by micro finite element analysis. Associations between bone microstructure, estimated bone strength, age, and menopause were analyzed. RESULTS: Trabecular number declined with age, and trabecular separation increased. SMI and TBPf increased, Conn.D and N.Nd/TV declined, and V*ms increased. Cortical BMD and thickness declined with age, and porosity increased. Stiffness and failure load decreased with age. Cortical thickness and estimated bone strength were affected by menopause. Cortical thickness was most associated with estimated bone strength. CONCLUSIONS: Trabecular and cortical bone microstructure were deteriorated markedly with age. Cortical thickness decreased after menopause and was most related to bone strength. Non-metric parameters give additional information about osteoporotic changes of trabecular bone.