A new assessment tool for ulnar drift in patients with rheumatoid arthritis using pathophysiological parameters of the metacarpophalangeal joint.

OBJECTIVES: To establish a new assessment tool for ulnar drift (UD) in rheumatoid arthritis (RA). METHODS: We established an observational cohort of 67 patients (134 rheumatoid hands) beginning in 2004. Fifty-two patients (100 hands) had follow-up in 2009 and 37 patients (63 hands) completed follow-up in 2015. UD was evaluated with the Fearnley classification and our scoring method, which assesses four parameters of the metacarpophalangeal joint. Cluster analysis using UD parameters divided hands into groups. Changes in UD over time, correlation of the Fearnley stage and cluster with a functional assessment, and reliability of the parameters were analyzed. RESULTS: UD increased and worsened over time according to the trend test. A dendrogram indicated five clusters would be appropriate. Both the Fearnley classification and cluster were associated with function; however, our method related to function more linearly (R-squared: 0.42). We found one type of hand in which bone destruction precedes the joint dislocation and one type in which joint dislocation progresses with little deviation during UD progression. CONCLUSION: Our UD evaluation appeared to be simple and related to function. Additionally, it enables dividing UD hands into five stages. Thus, our assessment should be beneficial compared to the Fearnley classification in considering treatments of UD.

Usefulness of Sweep Imaging With Fourier Transform for Evaluation of Cortical Bone in Diabetic Rats.

BACKGROUND: Diabetes decreases bone strength, possibly because of cortical bone changes. Sweep imaging with Fourier transform (SWIFT) has been reported to be useful for cortical bone evaluation. PURPOSE: To evaluate cortical bone changes in diabetic rats using SWIFT, assess the usefulness of this technique through comparisons with microcomputed tomography (µCT) and conventional MRI, and clarify the mechanism underlying cortical bone changes using histomorphometry STUDY TYPE: Animal cohort. ANIMAL MODEL: 8-week-old male Wistar/ST rats (N = 36) were divided into diabetes (induced by streptozotocin injection) and control groups. FIELD STRENGTH/SEQUENCE: 7.04T MRI, SWIFT. ASSESSMENT: Six animals from each group were sacrificed at 2, 4, and 8 weeks after injection. Tibial bones were extracted and evaluated using µCT and MRI. The cortical bone mineral density (BMD) was measured using µCT. Proton density-weighted imaging (PDWI) and SWIFT were also performed. The signal-to-noise ratio (SNR) was calculated for each acquisition. The bone formation rate was evaluated using histomorphometry. STATISTICAL TESTS: Findings at each timepoint were compared using Mann-Whitney U-tests. RESULTS: Cortical BMD was significantly lower in the diabetes group than in the control group only at 8 weeks (P < 0.05). At all timepoints, PDWI-SNR showed no significant differences between groups (P = 0.59, 0.70, and 0.82 at 2, 4, and 8 weeks, respectively). SWIFT-SNR was significantly lower in the diabetes group than in the control group (P < 0.05 at 2 and 4 weeks and P < 0.01 at 8 weeks), and the bone formation rate was significantly lower in the diabetes group than in the control group (P < 0.01 for all). DATA CONCLUSION: SWIFT can detect cortical bone changes even before a decline in the cortical BMD in a diabetic model. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2018;48:389-397.

Direct conversion of human fibroblasts into functional osteoblasts by defined factors.

Osteoblasts produce calcified bone matrix and contribute to bone formation and remodeling. In this study, we established a procedure to directly convert human fibroblasts into osteoblasts by transducing some defined factors and culturing in osteogenic medium. Osteoblast-specific transcription factors, Runt-related transcription factor 2 (Runx2), and Osterix, in combination with Octamer-binding transcription factor 3/4 (Oct4) and L-Myc (RXOL) transduction, converted ∼ 80% of the fibroblasts into osteocalcin-producing cells. The directly converted osteoblasts (dOBs) induced by RXOL displayed a similar gene expression profile as normal human osteoblasts and contributed to bone repair after transplantation into immunodeficient mice at artificial bone defect lesions. The dOBs expressed endogenous Runx2 and Osterix, and did not require continuous expression of the exogenous genes to maintain their phenotype. Another combination, Oct4 plus L-Myc (OL), also induced fibroblasts to produce bone matrix, but the OL-transduced cells did not express Osterix and exhibited a more distant gene expression profile to osteoblasts compared with RXOL-transduced cells. These findings strongly suggest successful direct reprogramming of fibroblasts into functional osteoblasts by RXOL, a technology that may provide bone regeneration therapy against bone disorders.

Outcome of Low-Invasive Local Split-Thickness Lengthening for Iliotibial Band Friction Syndrome.

Conventional surgical methods for iliotibial band friction syndrome (ITBFS) may affect the iliotibial band (ITB), delaying return to sports activities or impeding performance. We have developed a minimally invasive method. This study retrospectively analyzed the outcomes of this procedure in individuals with ITBFS. This study included 34 knees of 31 individuals. Surgery involved lengthening the central part of the ITB by splitting it into a superficial and a deep layer, maintaining the anterior and posterior fibers immediately above the lateral epicondyle. Outcomes included time to resume sports activity, personal best times to run a 5000-m race before and after surgery, and 2-month post-surgery muscle strengths. The mean postoperative time to return to competition was 5.8 weeks. Personal best times of 5000-m race improved in 13 of 17 runners. Two months post-surgery, the mean extensor muscle strengths on the healthy and affected sides did not significantly differ nor did the flexor muscle strengths. In ITBFS, the ITB itself is normal. Lengthening the limited region of the ITB immediately above the lateral femoral epicondyle removes the cause of ITBFS, with a reduction in inflammation. This technique resulted in early return to competition without degrading performance.

Length change patterns and shape of a grafted tendon after anatomical medial patellofemoral ligament reconstruction differs from that in a healthy knee.

PURPOSE: Recurrent patellar dislocation is currently treated with anatomical reconstruction of the medial patellofemoral ligament (MPFL), and favourable postoperative outcomes have been reported. However, it is uncertain if healthy MPFL function is restored by anatomical reconstruction. The hypothesis in this study was that stabilization of the patella following MPFL reconstruction would be improved compared with that before surgery, but that function of the grafted tendon would differ from that of a healthy MPFL. The objective was to analyse the length change patterns of the MPFL before surgery and the grafted tendon after surgery in patients with recurrent patellar dislocation treated with anatomical MPFL reconstruction. METHODS: The subjects were 12 patients (13 knees) in whom recurrent patellar dislocation was treated with anatomical MPFL reconstruction. The length change patterns of the MPFL and reconstructed ligament were analysed at extension and flexion of the knee joint using open MRI. RESULTS: The postoperative grafted tendon length was significantly shorter than that of the preoperative MPFL at knee extension, and significantly longer at 90° and 120° of knee flexion. The postoperative length of the grafted tendon only changed slightly from 0° to 30° of knee flexion, and then significantly decreased at flexion of 30° or more. The morphology of the grafted tendon was linear until 60° knee flexion, but became convex toward the extraarticular side at flexion of 90° or more. CONCLUSION: The grafted tendon length at knee extension was shorter than that of the preoperative MPFL, but there was no significant difference at 30° flexion. These findings suggest that the effect of damping of the patella with a grafted tendon after MPFL reconstruction may differ from that in a healthy knee. In addition, the morphology at 60° knee flexion was improved to linear after surgery, suggesting that ligament morphology at this flexion was normalized by MPFL reconstruction. LEVEL OF EVIDENCE: III.

Therapeutic outcomes of muscular advancement by an arthroscopic-assisted modified Debeyre-Patte procedure for irreparable large and massive rotator cuff tears.

BACKGROUND: In cases of the large or massive rotator cuff tears, retear rates after rotator cuff repairs remain high. We introduced an arthroscopic-assisted modified Debeyre-Patte procedure which enables to decrease the tension of torn rotator cuff by sliding supraspinatus and infraspinatus laterally keeping fascia connection to the rhomboids. PURPOSE: The objective of this study was to examine the clinical outcomes and retear rates after an arthroscopic-assisted modified Debeyre-Patte procedure for irreparable large and massive rotator cuff tears. METHODS: Thirty-three rotator cuff tear patients (34 shoulders) were selected. These patients underwent arthroscopic-assisted modified Debeyre-Patte procedures and were observed postoperatively for at least 24 months. Magnetic resonance imaging (MRI) was used to evaluate the preoperative location of the torn rotator cuff stump and fatty infiltration of the muscles composing the rotator cuff, as well as the repaired rotator cuffs. Shoulder functional evaluations through the use of the Constant and Murley scores and the University of California Los Angeles (UCLA) shoulder score were compared before and after surgery, and the preoperative global fatty degeneration index (GFDI) was compared between retear and healed shoulders. RESULTS: MRI showed that 77% of shoulders were healed and 23% exhibited retear postoperatively. The mean preoperative GFDI was 1.99 among the 26 healed shoulders and 2.54 among the 8 retear shoulders (p < .05). When the Goutallier's classification was grade 3 or lower for all 3 cuff muscles for fatty infiltration, the retear rate was 14.3%. The mean Constant and Murley scores in healed and retear groups respectively improved from 34.7 ± 15.8, 30.0 ± 15.1 points (p = 0.47) preoperatively to 70.8 ± 8.3, 53.9 ± 14.0 points (p < .001), and UCLA scores in healed and retear groups from 13.8 ± 3.9, 12.4 ± 5.0 points (p = 0.46) preoperatively to 32.8 ± 2.7, 28.4 ± 3.6 points (p < .001). CONCLUSION: The clinical outcomes of healed shoulders after the arthroscopic-assisted modified Debeyre-Patte procedure were favorable. If the torn rotator cuff stump is retracted near the glenoid fossa, and the rotator cuff muscle scored Goutallier grade 3 or lower, this modified Debeyre-Patte procedure would be a viable option.

Effect of Footprint Preparation on Tendon-to-Bone Healing: A Histologic and Biomechanical Study in a Rat Rotator Cuff Repair Model.

PURPOSE: To compare the histologic and biomechanical effects of 3 different footprint preparations for repair of tendon-to-bone insertions and to assess the behavior of bone marrow-derived cells in each method of insertion repair. METHODS: We randomized 81 male Sprague-Dawley rats and green fluorescent protein-bone marrow chimeric rats into 3 groups. In group A, we performed rotator cuff repair after separating the supraspinatus tendon from the greater tuberosity and removing the residual tendon tissue. In group B, we also drilled 3 holes into the footprint. The native fibrocartilage was preserved in groups A and B. In group C, we excavated the footprint until the cancellous bone was exposed. Histologic repair of the tendon-to-bone insertion, behavior of the bone marrow-derived cells, and ultimate force to failure were examined postoperatively. RESULTS: The areas of metachromasia in groups A, B, and C were 0.033 ± 0.019, 0.089 ± 0.022, and 0.002 ± 0.001 mm2/mm2, respectively, at 4 weeks and 0.029 ± 0.022, 0.090 ± 0.039, and 0.003 ± 0.001 mm2/mm2, respectively, at 8 weeks. At 4 and 8 weeks postoperatively, significantly higher cartilage matrix production was observed in group B than in group C (4 weeks, P = .002; 8 weeks, P < .001). In green fluorescent protein-bone marrow chimeric rats in group B, bone marrow-derived chondrogenic cells infiltrated the fibrocartilage layer. Ultimate force to failure was significantly higher in group B (19.7 ± 3.4 N) than in group C (16.7 ± 2.0 N) at 8 weeks (P = .031). CONCLUSIONS: Drilling into the footprint and preserving the fibrocartilage improved the quality of repair tissue and biomechanical strength at the tendon-to-bone insertion after rotator cuff repair in an animal model. CLINICAL RELEVANCE: Drilling into the footprint and preserving the fibrocartilage can enhance repair of tendon-to-bone insertions. This method may be clinically useful in rotator cuff repair.

Comparative analysis of medial patellofemoral ligament length change pattern in patients with patellar dislocation using open-MRI.

PURPOSE: Medial patellofemoral ligament (MPFL) reconstruction has become a common form of treatment for recurrent patellar dislocation. This study was performed using open-MRI to compare the length change pattern of MPFL in patients with a history of patellar dislocation to that in healthy subjects. METHODS: The subjects comprised 10 knees of 8 males and 13 knees of 12 females with a history of one or more patellar dislocations. The length of the MPFL was measured using open-MRI in both the leg-extended position and knee-flexed positions to analyse the length change pattern. RESULTS: The average MPFL lengths were 58.6 ± 6.5 mm and 52.0 ± 4.6 mm for males and females in the extended knee position, respectively. The length change pattern of the MPFL showed slight variation up to a flexion angle of 30° and a clear decrease above 30°. This pattern differed from that of normal MPFL. In terms of morphology, the fibre bundle of the damaged MPFL followed a convex course towards the side of the patellofemoral joint surface at a knee flexion angle of 60°, whereas that of the normal MPFL followed a straight course. CONCLUSION: The in vivo damaged MPFL length change pattern was specific and differed distinctly from that of normal MPFL. The results of the present study suggested that MPFL fibres with a history of patellar dislocation lack sufficient tension at knee flexion angles of 0°-60°. However, further studies are needed to obtain a better understanding of cases with a patellar dislocation or postsurgical cases of MPFL reconstruction. LEVEL OF EVIDENCE: III.

Examination of the Correlation Between Foot Morphology Measurements Using Pedography and Radiographic Measurements.

Pedography provides excellent visualization of the footprint. However, the correlation between the footprint images and radiographic measures has not been thoroughly evaluated. Therefore, the objectives of our study were to examine the correlation between the pedography-based measures of foot morphology and radiographic measurements and to propose reference values for the diagnosis of flatfoot using footprint imaging. The plantar footprints of 100 right feet were photographed using a pedography standing platform. The sole and arch areas were measured to calculate the footprint index (FPI). The lateral talar-first metatarsal angle (LTM) and calcaneal pitch angle (CP) were measured on standing lateral radiographs, and the talonavicular coverage angle was measured on frontal radiographs. The Pearson moment correlation between the FPI and radiography-based measures was calculated. The area under the receiver operating characteristic curve was calculated using an LTM of <-4° as the identifying criterion of flatfoot. The sensitivity and specificity of FPI were calculated for LTM values <-4°. The FPI correlated with the LTM (y = -17.964 ± 52.644x, R = 0.588) and CP (y = 9.2304 ± 27.739x, R = 0.659) but not with the talonavicular coverage angle (y = 26.01 ± 15.78x, R = 0.207). The area under the receiver operating characteristic curve was 0.753, with a cutoff FPI of 0.208, yielding a sensitivity of 0.462 and specificity of 0.934 for flatfoot identification. Pedography could provide an easy screening tool for flatfoot, with an FPI cutoff of 0.208, yielding a specificity of 93.4%.

Subperiosteal inflammatory pseudotumor mimicking primary malignant bone tumor: A case report.

We report a case of IgG4-positive inflammatory pseudotumor mimicking malignant bone tumor. Biopsy revealed no tumor cells. Surgical excision was performed and an abscess developing beneath the periosteum was observed with Streptococcus constellatus. Preoperative serum IgG4 value of 120 mg/dl normalized postoperatively to 80.6 mg/dl. It was difficult to distinguish inflammatory pseudotumor from sarcoma because it developed under the periosteum. In such cases, it is important to measure blood IgG4 values and perform tissue staining and culturing.

Recurrence of deformity after silicone implant and resection arthroplasty of the metatarsophalangeal joint for rheumatoid arthritis: long-term results.

OBJECTIVE: To examine the recurrence of deformity after silicone implant arthroplasty combined with resection arthroplasty for severe forefoot deformity in patients with rheumatoid arthritis. METHODS: We reviewed the long-term results of this procedure for 27 feet in 15 patients. Their average age and disease duration at the time of operation were 58.6 years and 17.5 years, respectively, and the average follow-up period was 10.3 years. RESULTS: An improved hallux valgus angle (45.3° preoperatively, 23.6° 6 months after operation) was maintained. By contrast, deformity and dislocation of lesser toe had recurred at the final follow-up; the angle between the proximal phalanx and the metatarsal of the second toe improved 13.4° with recurrence of 22.5°, the angle between the proximal phalanx and ground surface improved 22.4° with recurrence of 34.5. Furthermore, claw toe deformity at the final follow-up was significantly worse in the group whose hallux valgus deformity was observed 6 months after operation. CONCLUSION: This procedure could maintain the alignment of the first metatarsophalangeal joint, but the recurrence of claw toe deformity is a problem and the relation between the first toe and the lesser toe is an important consideration.

New quantitative ultrasound techniques for bone analysis at the distal radius in hip fracture cases: differences between femoral neck and trochanteric fractures.

BACKGROUND: Ample evidence on etiological and pathological differences between femoral neck and trochanteric fracture cases suggests the possibility of individualized treatment. There are many issues related to areal bone mineral density and other quantitative computed tomography parameters of the proximal femur. Although osteoporosis is a systemic problem, little has been reported regarding differences in bone structural parameters, including bone mineral density, between them in regions other than the proximal femur. METHODS: Participants were consecutive female patients >50 years of age admitted to the Saiseikai Suita Hospital (Osaka prefecture, Japan) for their first hip fracture between January 2012 and September 2014. Cortical thickness (CoTh, mm), volumetric trabecular bone mineral density (TBD, mg/cm3), and elastic modulus of trabecular bone (EMTb, GPa) were obtained as the new QUS parameters using the LD-100 system (Oyo Electric, Kyoto, Japan). The mean values of these parameters were compared between femoral neck and trochanteric fracture cases. In addition, correlations between age and each QUS parameter were investigated for each fracture type. A receiver operating characteristic (ROC) curve analysis was performed to examine the degree of effect each parameter on the fracture types. The area under the curve (AUC) for each parameter was compared to the AUC for age. RESULTS: There were 63 cases of femoral neck fracture (mean age, 78.2 years) and 37 cases of trochanteric fracture (mean age, 85.9 years). Mean TBD and EMTb were significantly higher for femoral neck fractures. There were significant negative correlations between QUS parameters and age for femoral neck fractures (P < 0.005). The regression lines for femoral neck fractures were above those for trochanteric fractures for TBD and EMTb. AUCs were 0.72 for age, and 0.61, 0.65, and 0.65 for CoTh, TBD, and EMTb, respectively. CONCLUSIONS: The new QUS parameters indicated that TR fracture cases were more osteoporotic than were FN fracture cases, even at the distal radius. There might be systemic differences between them, in addition to localized factors at the proximal femur.

Assessing coronal laxity in extension and flexion at a minimum of 10 years after primary total knee arthroplasty.

PURPOSE: Favourable long-term results after total knee arthroplasty (TKA) require appropriate soft tissue balance. However, the relationships between long-term results after TKA surgery and mediolateral laxities at extension and at 90° flexion remain unknown. This study therefore quantitatively assessed ligament balance at extension and at 90° knee flexion at least 10 years after primary TKA, as well as clarifying the relationships between long-term outcomes and mediolateral laxities. METHODS: This study included 49 knees (19 CR type and 30 PS type) of 33 patients followed up for at least 10 years after TKA at our hospital. Plain radiographs were obtained with about 150 N of varus or valgus stress using a Telos arthrometer at extension. At 90° flexion, epicondylar views were obtained under a 1.5-kg load and with about 10 kg of varus or valgus stress. RESULTS: Lateral laxity of about 5° was observed in both extension and flexion, with total laxities of varus and valgus stress each less than 10°. Postoperative clinical outcomes were good, with significant improvements in extension angle, femorotibial angle, and KSS, and no loosening in any knee. CONCLUSIONS: Good long-term results of TKA can be obtained with a lateral laxity of about 5°, equivalent to that of healthy knees. LEVEL OF EVIDENCE: III.

Hindfoot alignment at one year after total knee arthroplasty.

PURPOSE: It has previously been found that valgus hindfoot alignment (HFA) improves 3 weeks following total knee arthroplasty (TKA) for varus knee osteoarthritis (OA). In the present study, HFA was evaluated prior to TKA, as well as 3 weeks and 1 year following TKA. Using these multiple evaluations, the chronological effects of TKA on HFA were investigated. METHODS: The study included 71 patients (73 legs) who underwent TKA for varus knee OA. Radiograph examinations of the entire limb and hindfoot were performed in the standing position prior to TKA, as well as 3 weeks and 1 year following TKA. The varus-valgus angle was used as an indicator of HFA in the coronal plane. Patients were divided into two groups according to the preoperative varus-valgus angle: a hindfoot varus group (varus-valgus angle <76°) and a hindfoot valgus group (varus-valgus angle ≥76°). The changes in the varus-valgus angle were evaluated and compared in both groups. RESULTS: In the hindfoot valgus group, the mean ± standard deviation varus-valgus angle significantly declined from 80.5 ± 3.1° prior to TKA to 78.6 ± 3.7° 3 weeks following TKA and 77.1 ± 2.7° 1 year following TKA. However, in the hindfoot varus group, the mean varus-valgus angle prior to TKA (72.7 ± 2.6°) did not differ significantly from the mean varus-valgus angles 3 weeks (72.3 ± 3.3°) or 1 year (73.5 ± 3.0°) following TKA. CONCLUSIONS: HFA improved chronologically in legs with hindfoot valgus as a result of the alignment compensation ability of the hindfoot following TKA. However, no improvement was noted in legs with hindfoot varus because the alignment compensation ability of the hindfoot had been lost. The patients with hindfoot varus should be attended for ankle pain in the outpatient clinic after TKA. LEVEL OF EVIDENCE: III.

Magnetic resonance angiography evaluation of the bone tunnel and graft following ACL reconstruction with a hamstring tendon autograft.

PURPOSE: In this study, magnetic resonance angiography (MRA) was performed in the early phase after anterior cruciate ligament (ACL) reconstruction to analyse the changes in nutrient blood vessels and blood flow to the femoral and tibial tunnels and the intraosseous tendon grafts. METHODS: The subjects were 30 patients who underwent single-bundle ACL reconstruction with an autogenous hamstring tendon. MRA was performed at 2, 3, and 6 months postoperatively (n = 10 at each time point). The mean overall signal-to-noise ratios (SNRs) in the tunnel regions and in the region of the tendon graft were compared in each femur and tibia. RESULTS: Blood vessels from arteries reached the femoral and tibial tunnels 2 months postoperatively. The tunnel walls showed high signal intensity, while the intraosseous tendon grafts had lower intensity. SNRs showed significant differences between the femoral and tibial tunnels overall and the intraosseous tendon grafts. At 3 and 6 months postoperatively, the signal intensity of the tunnel walls was decreased significantly, while that of the intraosseous tendon grafts was also decreased, but not significantly. At these times, the SNRs of the femoral and tibial tunnels did not differ significantly, both overall and in the region of the intraosseous tendon grafts. CONCLUSION: Revascularization around the femoral and tibial tunnels occurred at 2 months postoperatively, with blood flow subsequently decreasing over time until 6 months. This revascularization may be involved in bone tendon healing and maturation of the tendon graft within the bone tunnels. Evaluations of revascularization by MRA may show the maturation stage of the graft and guide medical rehabilitation. LEVEL OF EVIDENCE: IV.

Prevalence of posterior elbow problems in Japanese high school baseball players.

BACKGROUND: Various posterior elbow problems cause posterior elbow pain among baseball players. We aimed to determine the prevalence and diagnoses associated with posterior elbow problems and post-treatment recovery time for returning to sports in Japanese high school baseball players when treated in the off-season. METHODS: A total of 576 Japanese high school baseball players who participated in baseball skill training camp during the off-season were enrolled in the study. The elbow of each player's throwing arm was assessed by use of a questionnaire and physical examination. Players with abnormal results were advised to visit the hospital. Players who visited the hospital were initially treated conservatively and underwent surgery if necessary. Retrospectively, players with positive physical examination results associated with posterior elbow pain, defined as olecranon tenderness and/or a positive elbow extension impingement test, were selected. Information about their position, elbow pain, physical examination results, diagnosis, treatment, and recovery time before returning to playing sports was assessed. RESULTS: Olecranon tenderness and/or positive elbow extension impingement test results were found in 76 players (13.2%). Of these, 33 agreed to visit the hospital for further diagnostic imaging and 25 players (75.8%) were diagnosed with posteromedial elbow impingement. By the next spring, 87.9% of players returned to sport, and 100% of players returned to sport before the next summer. The average recovery period was 77 ± 47 days. CONCLUSION: Physical examinations related to posterior elbow injuries were positive in 13.2% of high school baseball players. The most common diagnosis for posterior elbow pain was posteromedial elbow impingement. All players returned to competitive sports activity levels within 77 ± 47 days.

Clinical and basic research on steroid-induced osteonecrosis of the femoral head in Japan.

BACKGROUND: Steroid (glucocorticoid)-induced osteonecrosis of the femoral head (ONFH) in young adults has been a challenging disorder due to frequent incidence of collapse of the femoral head and resulting dysfunction of the hip joint and impairing quality of life. In Japan, the working group on ONFH in the Specific Disease Investigation Committee under auspices of the Japanese Ministry of Health, Labor and Welfare was founded in 1975, clinical and related basic research on ONFH have been continued for more than 40 years. EPIDEMIOLOGY AND CLINICAL COURSE: A national epidemiologic survey in 2004 estimated that 2200 new patients per year would be diagnosed with ONFH in Japan. ONFH was associated with steroid intake (51%), heavy alcohol intake (31%), both (3%), and neither (15%). The male-to-female ratio was 5:4, and the peak decades of age at definitive diagnosis were the 40s in male patients and the 30s in females. MRI studies revealed that ONFH would have occurred in early phase after start of steroid administration and no expansion of necrotic lesion within the femoral head in spite of continued steroid use. To standardize ONFH diagnosis and treatment strategy, the Committee established validated diagnostic criteria, a radiological staging system, and type categorization. TREATMENT OPTIONS: Most symptomatic patients with collapse of the femoral head require various surgical procedures. Joint preserving surgery, such as transtrochanteric rotational osteotomy and curved varus osteotomy, should be the treatment choice for young patients with healthy areas without severe collapse of the femoral head. CLINICAL AND RELATED BASIC RESEARCH: Clinical and basic research has been performed to determine the pathogenesis of steroid-induced ONFH. Low hepatic CYP3A activity has been reported to significantly contribute to the risk of steroid-induced ONFH. Several gene polymorphisms related to steroid metabolism were shown to be associated with the occurrence of ONFH.

Weight-bearing three-dimensional computed tomography analysis of the forefoot in patients with flatfoot deformity.

BACKGROUND: The recent classifications for posterior tibial tendon dysfunction (PTTD) stage II are based on forefoot deformity, but there is still no consensus regarding a detailed explanation of the clinical condition. The purposes of this study were to clarify the clinical condition of flatfoot deformity using three-dimensional (3D) computed tomography (CT) imaging under loading on both healthy and flat feet and to compare 3D movement of the forefoot in response to load. METHODS: Ten volunteers and 10 PTTD stage II patients with symptomatic flatfoot deformity were examined. CT scans of 20 healthy and 20 flat feet were performed under non-loading and full weight-bearing conditions. Images of the tibia and foot arch bones (talus, calcaneus, navicular, and first and fifth metatarsal bones) were reconstructed into 3D models. Rotations of individual tarsal bone or metatarsal bone were described by the Eulerian angles. RESULTS: Compared with healthy feet, flat feet experienced plantarflexion of the fifth metatarsal bone relative to the first metatarsal bone under loading conditions. We defined this phenomenon as synonymous with forefoot varus on the coronal plane. CONCLUSIONS: The results of this study have clarified part of the clinical condition of the forefoot in flatfoot deformity and may have applications in basic research of the staging advancement and substage classification of PTTD.

Quantitative evaluation of revascularization at bone tunnels and grafts with contrast-enhanced magnetic resonance angiography after anterior cruciate ligament reconstruction.

PURPOSE: Quantitative evaluation of vascular ingrowth to the bone tunnel walls and tendon graft after anterior cruciate ligament reconstruction for up to two years post-surgery using magnetic resonance angiography (MRA). METHODS: The study population consists of 100 patients that underwent reconstruction with multi-stranded semitendinosus tendons. The patients were retrospectively divided into those that underwent MRA two, three, four to six, and ≥ seven months after surgery (46, 17, 16, and 21 patients, respectively). Digital imaging and communication in medicine (DICOM) MRA images were imported into image processing software (OsiriX®), and the mean signal-to-noise ratio (SNR) of the bone tunnel walls in the femur and tibia and tendon graft parenchyma in the bone tunnels were measured. RESULTS: On MRA, the signal intensities of the bone tunnel walls in the femur and tibia (12.6 ± 3.41 and 10.7 ± 3.04) were greater than that in the tendon graft (2.65 ± 1.94 and 2.50 ± 2.02, respectively) at two months after surgery. At three months after surgery, the intensities of the tendon grafts (6.25 ± 2.18 and 5.77 ± 1.57, respectively) were greater than those of the bone tunnel wall (2.56 ± 1.29 and 2.50 ± 1.11, respectively). At four to six months, the intensities in the bone tunnel wall were 1.76 ± 0.73 and 1.62 ± 0.72, respectively, and those in the tendon graft were 5.01 ± 2.11 and 4.01 ± 2.35, respectively. At ≥ seven months after surgery, the intensities in the bone tunnel wall were 1.36 ± 0.63 and 1.21 ± 0.87, respectively, and those in the tendon graft were 4.25 ± 1.87 and 3.44 ± 1.99, respectively. CONCLUSION: Blood flow was seen around the bone tunnel on the femoral and tibial sides two months after ACL reconstruction and in the tendon graft parenchyma three months after surgery. The remodeling process continued after seven months.

Hypoxia Potentiates Anabolic Effects of Exogenous Hyaluronic Acid in Rat Articular Cartilage.

Hyaluronic acid (HA) is used clinically to treat osteoarthritis (OA), but its pharmacological effects under hypoxic conditions remain unclear. Articular chondrocytes in patients with OA are exposed to a hypoxic environment. This study investigated whether hypoxia could potentiate the anabolic effects of exogenous HA in rat articular cartilage and whether these mechanisms involved HA receptors. HA under hypoxic conditions significantly enhanced the expression of extracellular matrix genes and proteins in explant culture, as shown by real-time reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and dimethylmethylene blue (DMMB) assays. Staining with Safranin-O and immunohistochemical staining with antibody to type II collagen were also enhanced in pellet culture. The expression of CD44 was increased by hypoxia and significantly suppressed by transfection with siRNAs targeting hypoxia-inducible factor 1 alpha (siHIF-1α). These findings indicate that hypoxia potentiates the anabolic effects of exogenous HA by a mechanism in which HIF-1α positively regulates the expression of CD44, enhancing the binding affinity for exogenous HA. The anabolic effects of exogenous HA may increase as OA progresses.