Shier-Chieg Huang

Effects of severity of degeneration on gait patterns in patients with medial knee osteoarthritis

This study tested the hypothesis that patients with mild and severe medial knee osteoarthritis (OA) adopt different compensatory gait patterns to unload the deseased knee, in not only the frontal plane but also the sagittal plane. Fifteen patients with mild and 15 with severe bilateral medial knee OA, and 15 normal controls walked while the kinematic and kinetic data were measured. Compared to the normal group, both OA groups had significantly greater pelvic anterior tilt, swing-pelvis list, smaller standing knee abduction, as well as smaller standing hip flexor and knee extensor moments during stance. The severe group also had greater hip abduction, knee extension and ankle plantarflexion. The mild group successfully reduced the extensor moment and maintained normal abductor moment at the diseased knee mainly through listing and anterior tilting the pelvis. With extra compensatory changes at other joints and increased hip abductor moment, the severe group successfully reduced the knee extensor moment but failed to reduce the abductor moment. These results suggest that, apart from training of the knee muscles, training of the hip muscles and pelvic control are essential in the rehabilitative intervention of patients with knee OA, especially for more severe patients.

Cut-off point of the Scoliometer in school scoliosis screening.

Study Design. A large‐scale study on school screening for scoliosis was conducted to assess the referral rate, prevalence rate, and positive predictive value using different angles of trunk rotation as criteria for referral. Objective. To determine an ideal angle of trunk rotation cut‐off point to be used for referral in school screening for scoliosis. Summary of Background Data. When using the Scoliometer (Orthopedic Systems, Inc., Hayward, CA) in school scoliosis screening, 5° and 7° angles of trunk rotation have been recommended as criteria for referral. Low positive predictive values and over‐referral at these levels have been reported. Methods. The Adams forward bend test and Scoliometer measurement were combined for school scoliosis screening in 33,596 girls from the fifth, sixth and seventh grades. Nurses were the primary screeners. Girls with trunk rotation angles of 5° or more were referred for radiography. Results. The referral rate was 5.2%. By selecting 6°, 7°, 8°, 9° or 10° angles of trunk rotation as criteria for referral, the referral rate became 2.4%, 1.4%, 0.7%, 0.5%, or 0.3%, respectively. The prevalence rate for scoliosis equal to or larger than 10°, 20°, 30°, or 40° of the Cobb angle was 1.47%, 0.21%, 0.04% and 0.02%, respectively, by using a 5° angle of trunk rotation as the criterion for radiography. The positive predictive value was 28.3% for scoliosis of 10° or more, 4% for scoliosis of 20° or more, 0.8% for scoliosis of 30° or more, and 0.4% for scoliosis of 40° or more with a 5° angle of trunk rotation as the criterion for referral. By selecting angles of trunk rotation larger than 5° as criteria for referral for radiography, the positive predictive value increased, but positive cases with larger Cobb angles also decreased markedly. Conclusion. The optimal cut‐off point for referral when using the Scoliometer in school screening of scoliosis is still difficult to determine.

Age and height effects on the center of mass and center of pressure inclination angles during obstacle-crossing

Tripping over obstacles has been reported as one of the most frequent causes of falls in the elderly. Maintenance of the bodys balance and precise swing foot control is essential for successful obstacle-crossing. The aim of this study was thus to investigate the height and age effects on the center of mass (COM) and center of pressure (COP) inclination angles and angular velocities during obstacle-crossing. Ten healthy young and 15 healthy older adults were recruited to walk and cross obstacles of heights of 10%, 20% and 30% of their leg lengths. The COM and COP position data were calculated using data measured from a three-dimensional (3D) motion analysis system and forceplates. Smaller medial COM-COP inclination angles were found in the older group, suggesting that the neuromusculoskeletal system may have more room to control the swing foot with sufficient foot clearance. Decreased inclination angles with increasing obstacle height suggest that the subjects tended to keep their COM position close to the COP position to increase the bodys stability. Greater anterior inclination angular velocities were found in the older group to maintain the same inclination angles as the young. Not only inclination angles, but also COM-COP angular velocity, were useful for assessing ones ability to control the bodys dynamic stability.

A comparative study of nonoperative versus operative treatment of developmental dysplasia of the hip in patients of walking age

We retrospectively reviewed our results of treatment of two groups of children with developmental dysplasia of the hip (DDH) aged between 13 and 17 months. The nonoperative group consisted of 16 patients (17 hips) who were treated by closed reduction and casting with or without skin traction. There were four hips with mild degrees of avascular necrosis, and one hip with a failed reduction. Before further treatment, there were one hip in Severin class I, nine in class III, six in class IV, and one in class VI. Subsequent open reduction or pelvic osteotomy was required in those hips with failed reduction and residual dysplasia. The operative group consisted of 32 patients (32 hips). Open reduction and Salter osteotomy were performed without preoperative traction. There was one hip with redislocation due to improper use of a short spica and two hips with a mild degree of avascular necrosis. In > 2 years and 3 months of follow-up, 13 hips were in Severin class I, 18 in class II, and one in class III. The treatment time was significantly shortened in the operative group. We conclude that neglected DDH in patients of walking age can be safely and effectively treated by open reduction plus Salter osteotomy.

Sleeve fracture of the patella in children A report of five cases

pole.’ This is an uncommon type of fracture in children. Very few reports could be found in the literature. 4,7,9,12 From March 1984 to February 1988, we treated five patients with sleeve fracture of the patella. There were four boys and one girl, ranging in age from 8 to 12 years (mean, 11.2 years). The follow-up period ranged from 21 to 67 months (average, 22 months). All of the patients had the same mechanism of injury; they participated in sports that require jumping with sudden forceful extension of the takeoff knee (Table 1). Upon injury, sudden giving way with

Limb lengthening over an intramedullary nail. An animal study and clinical report.

With the goal of reducing the duration of external fixation in limb lengthening, the authors investigated the feasibility of limb lengthening over an intramedullary nail that could be statically locked when the desired length was achieved, permitting early removal of the external fixation device. In a preliminary study, 8 minigoats underwent 2.0-cm lengthening of the tibia by means of a uniplanar external fixator. Half of the goats had a reamed nail placed in the tibia at the initial surgery. By 10 weeks after lengthening, there no difference in radiographic, histologic, or biomechanical evidence of bone regeneration was found between the tibiae that were nailed and those that were not. In a following clinical series, 15 patients underwent tibial or femoral lengthening by means of a circular frame fixator with a reamed intramedullary nail in place. The postoperative course was uneventful except for 1 infection. The distraction gaps became ossified from 6 months to 1 year, and only 2 patients needed additional bone graftings. The joint function of the lengthened limb at last followup was good. Gradual limb lengthening with a reamed intramedullary nail in place is safe and effective and allows for early removal of the external fixation device.

Biomechanical strategies for successful obstacle crossing with the trailing limb in older adults with medial compartment knee osteoarthritis

To investigate the biomechanical strategy adopted by older adults with medial compartment knee osteoarthritis (OA) for successful obstacle crossing with the trailing limb, and to discuss its implications for fall-prevention, 15 older adults with bilateral medial compartment knee OA and 15 healthy controls were recruited to walk and cross obstacles of heights of 10%, 20%, and 30% of their leg lengths. Kinematic and kinetic data were obtained using a three-dimensional (3D) motion analysis system and forceplates. The OA group had higher trailing toe clearance than the controls. When the trailing toe was above the obstacle, the OA group showed greater swing hip abduction, yet smaller stance hip adduction, knee flexion, and ankle eversion. They showed greater pelvic anterior tilt and toe-out angle. They also exhibited greater peak knee abductor moments during early stance and at the instant when the swing toe was above the obstacle, while a greater peak hip abductor moment was found during late stance. Smaller knee extensor, yet greater hip extensor moments, were found in the OA group throughout the stance phase. In order to achieve higher toe clearance with knee OA, particular joint kinematic and kinetic strategies have been adopted by the OA group. Weakness in the hip abductors and extensors in individuals with OA may be risk factors for tripping owing to the greater demands on these muscle groups during obstacle crossing by these individuals.

Analysis of Osteonecrosis Following Pemberton Acetabuloplasty in Developmental Dysplasia of the Hip Long-Term Results

BACKGROUND The favorable results of Pemberton acetabuloplasty in children with developmental dysplasia of the hip have been well reported. We reviewed our long-term results related to osteonecrosis of the femoral head after this surgery, especially with regard to the effect of excessive inferior displacement of the femoral head. METHODS From 1993 to 1997, we performed 167 Pemberton acetabuloplasties in patients with developmental dysplasia of the hip who were eighteen months of age or older. Patients who had had prior treatment or developmental dysplasia of the hip due to neuromuscular disease were excluded. We selected patients who had unilateral developmental dysplasia of the hip, had undergone simultaneous open reduction and Pemberton acetabuloplasty between the ages of eighteen and thirty-six months, and had been followed for a minimum of ten years. Forty-nine patients met these criteria. The patients were divided into osteonecrosis-absent and osteonecrosis-present groups according to the criteria described by Kalamchi and MacEwen. Preoperative, interim follow-up and final radiographs were available for evaluation, as were the results of clinical examination. We used the femoral head inferior displacement percentage, measured on the radiographs, to quantify the amount of excessive correction postoperatively. Outcomes were measured with use of the McKay criteria and the Severin criteria. RESULTS The mean age at the time of surgery was 20.8 months, and the mean duration of follow-up was 134.6 months. Twenty-four patients (49%) were classified as not having osteonecrosis (the osteonecrosis-absent group) and twenty-five patients (51%), as having osteonecrosis (the osteonecrosis-present group). There were no significant differences between the two groups in terms of sex, age, laterality, Tönnis grade, or preoperative acetabular index. Seven of the cases of osteonecrosis were type I, thirteen were type II, one was type III, and four were type IV. The inferior displacement percentage revealed significant differences between the two groups (p < 0.0001). In the osteonecrosis-absent group, 96% of the patients had a radiographically satisfactory result (Severin class I or II); however, only 76% of the patients in the osteonecrosis-present group had a radiographically satisfactory result (p < 0.0001). According to the McKay criteria, there were significant clinical differences between the groups (p < 0.0001). CONCLUSIONS Our results showed significant correlation between excessive reduction of the femoral head and the development of osteonecrosis. In light of the high prevalence of type-II osteonecrosis, we postulated that the lateral epiphyseal branch of the medial circumflex artery was vulnerable to compression with increased inferior displacement of the femoral head. The latest radiographic and functional results corresponded to the severity of the osteonecrosis.

Ultrasound Stimulates NF-κB Activation and iNOS Expression Via the Ras/Raf/MEK/ERK Signaling Pathway in Cultured Preosteoblasts

It has been shown that ultrasound (US) stimulation accelerates fracture healing in the animal models and non‐operatively clinical uses. Nitric oxide (NO) is a crucial early mediator in mechanically induced bone formation. Here we found that US‐mediated inducible nitric oxide synthase (iNOS) expression was attenuated by Ras inhibitor (manumycin A), Raf‐1 inhibitor (GW5074), MEK inhibitor (PD98059), NF‐κB inhibitor (PDTC), and IκB protease inhibitor (TPCK). US‐induced Ras activation was inhibited by manumycin A. Raf‐1 phosphorylation at Ser338 by US was inhibited by manumycin A and GW5074. US‐induced MEK and ERK activation was inhibited by manumycin A, GW5074, and PD98059. Stimulation of preosteoblasts with US activated IκB kinase α/β (IKK α/β), IκBαphosphorylation, p65 phosphorylation at Ser276, p65, and p50 translocation from the cytosol to the nucleus, and κB‐luciferase activity. US‐mediated an increase of IKK α/β, IκBα, and p65 phosphorylation, κB‐luciferase activity and p65 and p50 binding to the NF‐κB element was inhibited by manumycin A, GW5074, and PD98059. Our results suggest that US increased iNOS expression in preosteoblasts via the Ras/Raf‐1/MEK/ERK/IKKαβ and NF‐κB signaling pathways. J. Cell. Physiol. 220: 196–203, 2009.

Outcomes of open reduction for developmental dysplasia of the hip: does bilateral dysplasia have a poorer outcome?

BACKGROUND The purpose of this study was to compare the outcomes of surgical treatment in children of walking age with unilateral and bilateral developmental dysplasia of the hip (DDH). METHODS We examined the records of fifty-six children of walking age with bilateral dysplasia and 156 children of walking age with unilateral dysplasia treated with open reduction and pelvic osteotomy with or without femoral osteotomy from 1990 to 2000. The minimum duration of follow-up was five years. The mean age at surgery was thirty-four months in the bilateral group and twenty-five months in the unilateral group. Preoperative radiographs were evaluated to determine the Tönnis grade of the dislocation and the acetabular index, and the latest radiographs were evaluated to determine the Severin classification. The Kalamchi and MacEwen classification was used to assess osteonecrosis, and the McKay classification was used to assess the clinical outcome at the time of the latest follow-up. For the statistical analyses, we selected the worse side in patients in the bilateral group as the index hip if the outcome was asymmetrical and the left hip if the outcome was symmetrical. The Fisher exact and Student t tests were used for comparisons of outcomes between the groups. Multiple logistic regression models were used to analyze factors associated with osteonecrosis and with the McKay classification. RESULTS Age at surgery and preoperative Tönnis grade differed significantly between the groups. Forty-five (80.3%) of the patients in the bilateral group and 135 (86.5%) of the patients in the unilateral group had a satisfactory Severin classification (Ia, Ib, or II); the difference between the groups was not significant. According to the McKay classification, twenty-six (46%) of the patients in the bilateral group had an satisfactory outcome compared with 111 (71%) of the patients in the unilateral group (p = 0.006). Osteonecrosis was significantly greater in the bilateral group as well (p = 0.01). Patient age at surgery and Tönnis grade were risk factors for osteonecrosis. Older age and bilaterality were associated with a poorer McKay classification. The logistic regression analysis was repeated after removing the nineteen patients (34%) in the bilateral group who had an asymmetrical outcome, and this analysis confirmed that asymmetrical outcome was a risk factor for a poorer McKay classification. CONCLUSIONS Our data confirmed that the clinical outcome of bilateral developmental dysplasia of the hip was worse primarily because of asymmetrical outcomes. Age and Tönnis grade played an important role in the risk of occurrence of osteonecrosis. The radiographic outcome according to the Severin classification did not differ significantly between the groups.