Immunohistochemistry for hMLH1 and hMSH2: a practical test for DNA mismatch repair-deficient tumors

Inactivation of deoxyribonucleic acid (DNA) mismatch repair genes, most commonly human mutL homologue 1 (hMLH1) or human mutS homologue 2 (hMSH2), is a recently described alternate pathway in cancer development and progression. The resulting genetic instability is characterized by widespread somatic mutations in tumor DNA, and is termed high-frequency microsatellite instability (MSI-H). Although described in a variety of tumors, mismatch repair deficiency has been studied predominantly in colorectal carcinoma. Most MSI-H colorectal carcinomas are sporadic, but some occur in patients with hereditary nonpolyposis colorectal cancer (HNPCC), and are associated with germline mutations in mismatch repair genes. Until now, the identification of MSI-H cancers has required molecular testing. To evaluate the role of immunohistochemistry as a new screening tool for mismatch repair-deficient neoplasms, the authors studied the expression of hMLH1 and hMSH2, using commercially available monoclonal antibodies, in 72 formalin-fixed, paraffin-embedded tumors that had been tested previously for microsatellite instability. They compared immunohistochemical patterns of 38 MSI-H neoplasms, including 16 cases from HNPCC patients with known germline mutations in hMLH1 or hMSH2, with 34 neoplasms that did not show microsatellite instability. Thirty-seven of 38 MSI-H neoplasms were predicted to have a mismatch repair gene defect, as demonstrated by the absence of hMLH1 and/or hMSH2 expression. This included correspondence with all 16 cases with germline mutations. All 34 microsatellite-stable cancers had intact staining with both antibodies. These findings clearly demonstrate that immunohistochemistry can discriminate accurately between MSI-H and microsatellite-stable tumors, providing a practical new technique with important clinical and research applications.

Direct medical costs of chronic obstructive pulmonary disease: chronic bronchitis and emphysema

In this study we aimed to estimate direct medical costs of Chronic Obstructive Pulmonary Disease (COPD) by disease type; chronic bronchitis and emphysema. This study estimates direct costs in 1996 dollars using a prevalence approach and both aggregate and microcosting. A societal perspective is taken using prevalence, and multiple national, state and local data sources are used to estimate health-care utilization and costs. Chronic bronchitis and emphysema together account for $14.5 billion in annual direct costs. Inpatient costs are greater than outpatient and emergency costs ($8.3 vs. $7.8 billion) and hospital and medication costs account for most resources spent. The high prevalence of chronic bronchitis accounts for its larger total costs ($11.7 billion) compared with emphysema ($2.8 billion). Emphysema, which is more severe, has higher costs per prevalent case ($1341 vs. $816). Hospital stays account for the highest costs, $6.0 billion for chronic bronchitis and $1.9 billion for emphysema. The hospitalization rate, length of stay and average cost per prevalent case are higher for emphysema than for chronic bronchitis. Medication costs are the second highest cost category ($4.4 billion for chronic bronchitis, $0.693 billion for emphysema). The high hospitalization and low home care costs (0.2% of total) suggest underuse of home care and room to shift from acute to preventive care. More attention to healthcare management of chronic bronchitis and emphysema is suggested, and improving inhaler and anti-smoking compliance might be important targets.

Daily cumulative hip moment is associated with radiographic progression of secondary hip osteoarthritis

OBJECTIVE

To investigate whether higher daily cumulative hip moment at baseline is associated with subsequent radiographic progression of hip osteoarthritis (OA) over 12 months.

DESIGN

Fifty patients with secondary hip OA, excluding patients with end-stage hip OA, participated in this prospective cohort study. Joint space width (JSW) of the hip was measured at baseline and 12 months later. With radiographic progression of hip OA (>0.5 mm/year in JSW) as dependent variable (yes/no), univariable and multivariable logistic regression analyses were performed to assess the association between load-related parameters during gait (i.e., peak hip moment, hip moment impulse, and daily cumulative hip moment [product of hip moment impulse and mean steps/day]) and hip OA progression with and without adjustment for age, body weight, and minimum JSW.

RESULTS

Of the 50 patients (47.4 ± 10.7 years old), 21 (42.0%) were classified into the progression group. The higher daily cumulative hip moment in the frontal plane at baseline was statistically significantly associated with radiographic progression of hip OA (adjusted odds ratio (OR) [95% confidence interval (CI)], 1.34 [1.06-1.70]; P = 0.013). The higher daily cumulative hip moment in the sagittal plane was also approaching significance in its association with hip OA progression (adjusted OR, 1.80 [0.99-3.26]; P = 0.052).

CONCLUSIONS

In the female patients with secondary hip OA, higher daily cumulative hip moment, particularly in the frontal plane, was a predictor of radiographic progression of hip OA over 12 months. Reduction in daily cumulative hip moment by modification in gait and physical activity may potentially slow hip OA progression.

A porous bioactive titanium implant for spinal interbody fusion: an experimental study using a canine model

Object

Porous biomaterials with adequate pore structure and appropriate mechanical properties are expected to provide a new generation of devices for spinal interbody fusion because of their potential to eliminate bone grafting. The purpose of this study was to evaluate the fusion characteristics of porous bioactive titanium implants using a canine anterior interbody fusion model.

Methods

Porous titanium implants sintered with volatile spacer particles (porosity 50%, average pore size 303 μm, compressive strength 116.3 MPa) were subjected to chemical and thermal treatments that give a bioactive microporous titania layer on the titanium surface (BT implant). Ten adult female beagle dogs underwent anterior lumbar interbody fusion at L6–7 using either BT implants or nontreated (NT) implants, followed by posterior spinous process wiring and facet screw fixation. Radiographic evaluations were performed at 1, 2, and 3 months postoperatively using X-ray fluoroscopy. Animals were killed 3 months postoperatively, and fusion status was evaluated by manual palpation and histological examination.

Results

Interbody fusion was confirmed in all five dogs in the BT group and three of five dogs in the NT group. Histological examination demonstrated a large amount of new bone formation with marrowlike tissue in the BT implants and primarily fibrous tissue formation in the NT implants.

Conclusions

Bioactive treatment effectively enhanced the fusion ability of the porous titanium implants. These findings, coupled with the appropriate mechanical properties in load-bearing conditions, indicate that these porous bioactive titanium implants represent a new generation of biomaterial for spinal interbody fusion.

Effects of high-velocity resistance training on muscle function, muscle properties, and physical performance in individuals with hip osteoarthritis: a randomized controlled trial

OBJECTIVE

To investigate the effects of high-velocity resistance training on muscle function, muscle properties, and physical performance in patients with hip osteoarthritis by comparison with those of low-velocity resistance training.

DESIGN

Single-blind randomized controlled trial.

SETTING

Home-based exercise programmes.

SUBJECTS

A total of 46 women with hip osteoarthritis were randomly assigned to the high-velocity (n = 23) or low-velocity (n = 23) training group.

INTERVENTIONS

Both groups underwent an eight-week daily home-based resistance training programme using an elastic band. Exercises involved hip abduction, extension, and flexion and knee extension. Participants in the high-velocity group performed the concentric phase of each repetition as rapidly as possible and returned to the initial position eccentrically in 3 s. Participants in the low-velocity group performed both the concentric and eccentric phases in 3 s.

MAIN MEASURES

The following outcome measures were evaluated: isometric muscle strength, muscle power, muscle thickness, muscle echo intensity, maximum walking speed, Timed Up and Go test, 3-minute walking test, Harris Hip Score, and hip pain.

RESULTS

Decreases in the time for performing the Timed Up and Go test (mean changes: high-velocity group -0.46 s, low-velocity group -0.23 s) and echo intensity of the gluteus maximus (mean changes: high-velocity group -6.8, low-velocity group -1.0) were significantly greater in the high-velocity group than in the low-velocity group. No significant difference was observed in changes of other outcome measures between the groups.

CONCLUSION

This study revealed that high-velocity training for patients with hip osteoarthritis has partially a greater effect on muscle properties and physical performance than low-velocity training.

Tolcapone enhances food-evoked dopamine efflux and executive memory processes mediated by the rat prefrontal cortex

BACKGROUND AND RATIONALE

Genetic variations in catechol-O-methyl transferase (COMT) or administration of COMT inhibitors have a robust impact on cognition and executive function in humans. The COMT enzyme breaks down extracellular dopamine (DA) and has a particularly important role in the prefrontal cortex (PFC) where DA transporters are sparse. As such, the beneficial cognitive effects of the COMT inhibitor tolcapone are postulated to be the result of increased bioavailability of DA in the PFC. Furthermore, it has been shown previously that COMT inhibitors increase pharmacologically evoked DA but do not affect basal levels in the PFC.

OBJECTIVES

The current study characterized the ability of tolcapone to increase DA release in response to behaviorally salient stimuli and improve performance of the delayed spatial win-shift (DSWSh) task.

RESULTS AND CONCLUSIONS

Tolcapone enhanced PFC DA efflux associated with the anticipation and consumption of food when compared to saline controls. Chronic and acute treatment with tolcapone also reduced the number of errors committed during acquisition of the DSWSh. However, no dissociable effects were observed in experiments designed to selectively assay encoding or recall in well-trained animals, as both experiments showed improvement with tolcapone treatment. Taken together, these data suggest a generalized positive influence on cognition. Furthermore, these data support the conclusion of Apud and Weinberger (CNS Drugs 21:535-557, 2007) that agents which selectively potentiate PFC DA release may confer cognitive enhancement without the unwanted side effects produced by drugs that increase basal DA levels in cortical and subcortical brain regions.

Muscle mass and composition of the hip, thigh and abdominal muscles in women with and without hip osteoarthritis

The objective of this study was to compare muscle mass and composition between individuals with and without hip osteoarthritis. Twenty-four women with hip osteoarthritis (OA group) and 16 healthy women (healthy group) participated in this study. Muscle thickness (MT) and echo intensity (EI) were measured as indices of muscle mass and composition, respectively, using ultrasound imaging. Seven muscles were examined: gluteus maximus, gluteus medius, quadriceps femoris, rectus abdominis, external oblique, internal oblique and transversus abdominis. MT of only quadriceps femoris in the OA group was significantly thinner than that in the healthy group. EIs of gluteus medius, quadriceps femoris and rectus abdominis were significantly higher in the OA group than those in the healthy group. Thus, actual contractile tissue of gluteus medius and rectus abdominis substantially decreased, although muscle mass was similar, whereas both quantitative and qualitative changes occurred in quadriceps femoris in patients with hip OA.

Accelerated degradation and improved bone-bonding ability of hydroxyapatite ceramics by the addition of glass

Dense hydroxyapatite (HA) ceramics are useful bone substitutes, but they degrade minimally. One solution is to incorporate degradable materials in the HA. In this study, we manufactured glass-containing HA and investigated whether the degradability and bone-bonding ability of the HA were improved. The glass-containing HA was manufactured from a mixture of HA powder and 1.0 wt% glass powder. The control HA was manufactured from pure HA powder. In vitro degradability was evaluated by soaking in physiological saline, and a rabbit model was used to evaluate in vivo degradability and bone-bonding ability. Detaching tests were performed for all removed samples to quantify bone-bonding ability of each type of HA. The glass-containing HA showed higher degradability than the control HA, both in vitro and in vivo. The detaching failure load of the glass-containing HA was rapidly elevated after implantation and was higher than that of the control HA. Our results suggest that the dissolution of the added glass made the glass-containing HA degradable and that the detaching failure load of the glass-containing HA was elevated by reinforcement of the mechanical locking at the roughened interface. Incorporation of glass additives into HA can be concluded to be a good candidate for producing a bone substitute that can partially degrade and bond to bone firmly and rapidly.

Increased numbers of lymphocytes with single class surface immunoglobulins in reactive hyperplasia of lymphoid tissue

Forty-seven lymph nodes and one stomach exhibiting reactive hyperplasia from 40 patients were examined by morphologic and immunologic methods. Twelve lymph nodes and one stomach from ten patients had a significantly increased number (greater than 25%) of lymphocytes, with single class surface immunoglobulins or plasma cells, and plasmacytoid lymphocytes secreting single class immunoglobulins. In three cases, a diagnosis of malignancy was subsequently made on the basis of morphological and immunological evidence of tumor in other tissue. Five patients had collagen disorders, two had a persistent unexplained hypergammaglobulinemia, and two had no recognized associated disease. The significance of an increase of B lymphocytes with single class surface immunoglobulins in these cases is presently not clear, but patients with similar findings should have extensive investigation and persistent follow-up.

Cemented total hip arthroplasty with subtrochanteric femoral shortening transverse osteotomy for severely dislocated hips: outcome with a 3- to 10-year follow-up period

BACKGROUND

Total hip arthroplasty (THA) for the treatment of severe dislocation of the hip is a technically demanding procedure. In most previous reports, techniques and clinical outcomes using cementless prostheses are widely reported, but there have been few reports on the technique and outcomes using cemented prostheses. The purpose of this study was to evaluate the outcomes of a cemented THA with a simultaneous subtrochanteric femoral shortening transverse osteotomy in patients with Crowe type III or IV developmental dysplasia of the hip.

METHODS

We retrospectively reviewed 15 hips in 11 patients who underwent cemented THA with subtrochanteric femoral shortening transverse osteotomy and with placement of the acetabular component at the level of the anatomic hip center. Patients were evaluated preoperatively and postoperatively with the Merle d'Aubigné and Postel hip score. Radiographic examination was performed to evaluate the level of the femoral osteotomy site, of the radiographic leg lengthening, and of bone union.

RESULTS

The clinical evaluation by the Merle d'Aubigné and Postel hip score was improved from 8.1 ± 2.5 preoperatively to 15.1 ± 1.3 at the time of final follow-up. Radiographic evidence of bone union at the osteotomy site appeared at more than 6 months after operation. Moreover, there were 3 (20%) nonunions that needed reoperation. No acetabular and femoral components exhibited radiological loosening at the time of final follow-up. In addition, one delayed union causing thigh pain was treated with low-intensity pulsed ultrasound that accelerated bone formation.

CONCLUSION

Our results in this study indicate that we should prevent instability at the transverse osteotomy site and an adequate intercalary cortical bone graft is needed to prevent nonunion in cemented THA combined with a subtrochanteric femoral shortening transverse osteotomy. We should apply this procedure with caution in patients, especially those who show less potential bone formation activity.

Revision total hip arthroplasty using a Kerboull-type acetabular reinforcement device with bone allograft

We retrospectively reviewed 40 hips in 36 patients who had undergone acetabular reconstruction using a titanium Kerboull-type acetabular reinforcement device with bone allografts between May 2001 and April 2006. Impacted bone allografts were used for the management of American Academy of Orthopaedic Surgeons Type II defects in 17 hips, and bulk bone allografts together with impacted allografts were used for the management of Type III defects in 23 hips. A total of five hips showed radiological failure at a mean follow-up of 6.7 years (4.5 to 9.3), two of which were infected. The mean pre-operative Merle d’Aubigné score was 10 (5 to 15) vs 13.6 (9 to 18) at the latest follow-up. The Kaplan-Meier survival rate at ten years, calculated using radiological failure or revision of the acetabular component for any reason as the endpoint, was 87% (95% confidence interval 76.3 to 97.7). A separate experimental analysis of the mechanical properties of the device and the load-displacement properties of bone grafts showed that a structurally hard allograft resected from femoral heads of patients with osteoarthritis should be preferentially used in any type of defect. If impacted bone allografts were used, a bone graft thickness of < 25 mm was acceptable in Type II defects.

This clinical study indicates that revision total hip replacement using the Kerboull-type acetabular reinforcement device with bone allografts yielded satisfactory mid-term results.

Is the bone-bonding ability of a cementless total hip prosthesis enhanced by alkaline and heat treatments?

BACKGROUND

Cementless total hip arthroplasty (THA) implants using alkaline and heat treatments were developed to enhance bone bonding. Although bone-bonding ability of the alkali- and heat-treated titanium surface has been demonstrated in animal studies, it remains unknown whether it enhances or provides durable bone bonding in humans.

QUESTIONS/PURPOSES

We therefore (1) determined long-term survivorship, function, and radiographic signs of failure of fixation of alkali- and heat-treated THA implants; and (2) histologically examined their bone-bonding ability in two human retrievals.

METHODS

We retrospectively reviewed 58 patients who underwent 70 primary THAs, of whom 67 were available for minimum followup of 8 years (average, 10 years; range, 8-12 years). Survival rate was calculated. Hip function was evaluated using the Japan Orthopaedic Association (JOA) hip scores, and radiographic signs of implant failure were determined from anteroposterior radiographs. Two retrieved implants were investigated histologically.

RESULTS

Using revision for any reason as the end point, the overall survival rate was 98% (95% confidence interval, 96%-100%) at 10 years. The patients' average JOA hip scores improved from 47 points preoperatively to 91 points at the time of the last followup. No implant had radiographic signs of loosening. Histologically we observed bone in the pores 2 weeks after implantation in one specimen and apparently direct bonding between bone and the titanium surface in its deep pores 8 years after implantation.

CONCLUSIONS

Cementless THA implants with alkaline and heat treatments showed a high survival rate. Further study is required to determine whether the treatment enhances direct bone bonding.

Cervical myelocystocele with Chiari II malformation: magnetic resonance imaging and surgical treatment

BACKGROUND

The myelocystocele is a rare clinical entity, and there have only been six case reports concerning the cervical myelocystocele, including ours.

METHODS

The case of a female neonate with cervical myelocystocele, who presented with respiratory distress beginning at birth is reported.

RESULTS

Magnetic resonance (MR) imaging disclosed a cystic lesion surrounded by two layers of membrane, which were recognized to be the dural and arachnoid layer and the ependymal lining layer, respectively, during operation and on histopathologic examination. Hydromyelia at C2-C7 with Chiari II malformation was also observed. After a thorough repair and untethering surgery, the hydromyelia was diminished on a follow-up MR examination. The patient's respiratory status normalized several days postoperatively, and her growth and development were within normal limits at the 2-year follow-up.

CONCLUSIONS

In cases of cervical myelocystocele with Chiari II malformation, untethering through intradural exploration to treat the tethered cord and outer decompression of the foramen magnum are needed. MR imaging is the best modality for preoperative determination of anatomic relationships.

Antidegenerative effects of partial disc replacement in an animal surgery model

STUDY DESIGN

In vivo degenerative changes of rabbit intervertebral discs after partial disc replacements were evaluated radiologically and histologically in a controlled trial.

OBJECTIVE

To demonstrate the therapeutic effects of partial disc replacement in an animal surgical model.

SUMMARY OF BACKGROUND DATA

Although some authors reported that partial disc replacements have beneficial clinical outcomes, there are few controlled animal studies in which the therapeutic effects of this procedure have been demonstrated.

METHODS

The implants for partial disc replacements were made of poly (vinyl alcohol) hydrogel and rod-shaped. The L2-L3 or L3-L4 intervertebral discs of Japanese white rabbits were pierced with a 2.0-mm Kirschner wire and implants were inserted into the holes. For comparative purposes, the adjacent discs underwent sham treatments or control treatments in which the disc was pierced but no implant was inserted. Sixty discs from 30 rabbits were analyzed radiologically and histologically for degenerative changes at 1, 3, or 6 months after surgery.

RESULTS

Radiologic analysis revealed that significantly less disc height was lost with the replacement treatment than with the control treatment. Change in disc height after the replacement treatment was not significantly different from that after the sham treatment. Histologic degeneration of the replaced discs was delayed in comparison with that of the control discs but progressed with time.

CONCLUSIONS

The antidegenerative effects of partial disc replacement surgery were demonstrated by quantitative radiologic and histologic analyses. Degeneration of the anulus fibrosus after the replacement treatment was delayed by preserving disc height and occupying the space of the nucleus pulposus. Properly designed implants and minimally invasive techniques are necessary for long-term success.

Lowering levels of bed occupancy is associated with decreased inhospital mortality and improved performance on the 4-hour target in a UK District General Hospital

OBJECTIVE

To evaluate whether there is an association between an intervention to reduce medical bed occupancy and performance on the 4-hour target and hospital mortality.

METHODS

This before-and-after study was undertaken in a large UK District General Hospital over a 32 month period. A range of interventions were undertaken to reduce medical bed occupancy within the Trust. Performance on the 4-hour target and hospital mortality (hospital standardised mortality ratio (HSMR), summary hospital-level mortality indicator (SHMI) and crude mortality) were compared before, and after, intervention. Daily data on medical bed occupancy and percentage of patients meeting the 4-hour target was collected from hospital records. Segmented regression analysis of interrupted time-series method was used to estimate the changes in levels and trends in average medical bed occupancy, monthly performance on the target and monthly mortality measures (HSMR, SHMI and crude mortality) that followed the intervention.

RESULTS

Mean medical bed occupancy decreased significantly from 93.7% to 90.2% (p=0.02). The trend change in target performance, when comparing preintervention and postintervention, revealed a significant improvement (p=0.019). The intervention was associated with a mean reduction in all markers of mortality (range 4.5-4.8%). SHMI (p=0.02) and crude mortality (p=0.018) showed significant trend changes after intervention.

CONCLUSIONS

Lowering medical bed occupancy is associated with reduced patient mortality and improved ability of the acute Trust to achieve the 95% 4-hour target. Whole system transformation is required to create lower average medical bed occupancy.

Sagittal alignment and mobility of the thoracolumbar spine are associated with radiographic progression of secondary hip osteoarthritis

OBJECTIVE

To identify predictors of radiographic progression of hip osteoarthritis (OA) over 12 months among functional hip impairments and spinal alignment and mobility.

DESIGN

Fifty female patients with secondary hip OA, excluding those with end-stage hip OA, participated in this prospective cohort study. Joint space width (JSW) of the hip was measured at baseline and 12 months later. With radiographic progression of hip OA over 12 months (>0.5 mm in JSW) as dependent variable, logistic regression analyses were performed to identify predictors for hip OA progression among functional impairments of the hip and spine with and without adjustment for age, body mass index (BMI), and minimum JSW at baseline. The independent variables were hip pain, Harris hip score (HHS), hip morphological parameters, hip passive range of motion (ROM) and muscle strength, and alignment and mobility of the thoracolumbar spine at baseline.

RESULTS

Twenty-one (42.0%) patients demonstrated radiographic progression of hip OA. Multivariable logistic regression analysis showed that larger anterior inclination of the spine in standing position (adjusted OR [95% CI], 1.37 [1.04-1.80]; P = 0.028) and less thoracolumbar spine mobility (adjusted OR [95% CI], 0.96 [0.92-0.99]; P = 0.037) at baseline were statistically significantly associated with radiographic progression of hip OA, even after adjustment for age, BMI, and minimum JSW.

CONCLUSIONS

The findings suggest that spinal alignment and mobility should be considered when assessing risk and designing preventive intervention for radiographic progression of secondary hip OA.

Minimum 10-Year Wear Analysis of Highly Cross-Linked Polyethylene in Cementless Total Hip Arthroplasty

Fifty-four patients (64 hips) underwent cementless total hip arthroplasty between 2000 and 2003 with a 22-mm zirconia ceramic bearing on highly cross-linked polyethylene, and were evaluated with a mean 11.9-year postoperative follow-up (range, 10-14 years). Linear wear was measured on the anteroposterior radiograph of the hip. No evidence of osteolysis and loosening was found on the final radiograph in any of the cases, and the steady-state linear wear rate was 0.017±0.018 mm/year. No significant correlation was found between the linear wear rate and age, body weight, cup inclination angle, or polyethylene thickness. Highly cross-linked polyethylene showed excellent wear resistance for >10 years when used in combination with 22-mm zirconia heads.

Visual callosal, corticotectal and corticogeniculate projections in golden hamsters

Visual callosal projections were identified in the hamster by terminal degeneration after total transection of the corpus callosum. A dense trilaminar callosal terminal field was observed to form a belt around area 17. The subcortical projections from area 17 were studied using the autoradiographic method. Evidence for a topographic organization is presented for projections from area 17 to the superior colluculus, the dorsal and ventral nuclei of the lateral geniculate body. The totography of the projections are in accord with known patterns of distribution of the retina upon these structures in the hamster.

Influence of occlusal contact on cervical muscle activity during submaximal clenching

The aim of this study was to clarify the relationship between changes in the occlusal contact area and cervical muscle activity. A decreases in the occlusal contact area using bite planes (stage 1: full contact bite plane, stage 2: bilateral molar removed from contact, and stage 3: bilateral molar and premolar removed from contact) was experimentally simulated in seven subjects (aged 23-25 years) with normal dentition, and muscle activity of the sternocleidomastoid muscle (SCM) and trapezius muscle (TRM) during 50 and 10% of maximum voluntary contraction (MVC) was measured by surface electromyography. The SCM activity during 50% MVC was stage 1: 31.2 +/- 9.4 microV and stage 3: 35.3 +/- 12.3 microV. The TRM activity during 50% MVC was stage 1: 15.2 +/- 0.7 microV and stage 3: 18.3 +/- 2.9 microV. At the 50% MVC, stage 3 showed significant differences in comparison with stage 1 (P < 0.05, anova). These findings suggested that the sternocleidomastoid and TRM play roles in the exertion of occlusal force, and decreases in the occlusal contact area influence the amount of SCM and TRM activity.

Hip external rotator exercise contributes to improving physical functions in the early stage after total hip arthroplasty using an anterolateral approach: a randomized controlled trial

PURPOSE

The purpose of this study was to investigate the effects of an exercise program focusing on hip external rotator muscle on physical recovery in the early post-operative period of total hip arthroplasty (THA).

METHODS

Patients who underwent THA were randomized to an exercise group (n = 14) or a control group (n = 14). In exercise group, the hip external rotator exercise program was performed 5 times per week for four weeks. Outcome measures were hip pain, hip range of motion, muscle strength of lower extremity and Timed Up and Go (TUG) test.

RESULTS

Both the hip abductor strength (effect size = 0.60) and TUG test (effect size= -0.53) in the exercise group improved significantly after the intervention.

CONCLUSIONS

The results of the present study demonstrated that exercise program focusing on hip external rotator muscle was an effective intervention, especially in improving both hip abductor strength and walking ability in the acute post-THA stage. Implication for Rehabilitation After THA, in order to safely progress patients back to their desired activity level, there is a need to develop rehabilitation strategies to expedite and promote the recovery during the acute postoperative period. Exercise program focusing on hip external rotator muscle may lead to significant improvement of hip abductor muscle strength and gait ability in the acute post-THA stage.

The olfactory conditioning in the early postnatal period stimulated neural stem/progenitor cells in the subventricular zone and increased neurogenesis in the olfactory bulb of rats

The olfactory memory acquired during the early postnatal period is known to be maintained for a long period, however, its neural mechanism remains to be clarified. In the present study, we examined the effect of olfactory conditioning during the early postnatal period on neurogenesis in the olfactory bulb of rats. Using the bromodeoxyuridine-pulse chase method, we found that the olfactory conditioning, which was a paired presentation of citral odor (conditioned stimulus) and foot shock (unconditioned stimulus) in rat pups on postnatal day 11, stimulated the proliferation of neural stem/progenitor cells in the anterior subventricular zone (aSVZ), but not in the olfactory bulb, at 24 h after the conditioning. However, the number of newborn cells in the olfactory bulb was increased at 2 weeks, but not 8 weeks, after such conditioning. Neither the exposure of a citral odor alone nor foot shock alone affected the proliferation of neural stem/progenitor cells in the aSVZ at 24 h after and the number of newborn cells in the olfactory bulb at 2 weeks after. The majority of newborn cells in the olfactory bulb of either the conditioned rats or the unconditioned rats expressed the neural marker NeuN, thus indicating that the olfactory conditioning stimulated neurogenesis in the olfactory bulb. These results suggest that olfactory conditioning during the early postnatal period temporally stimulates neurogenesis in the olfactory bulb of rats.

Clinical outcomes of cemented double-tapered titanium femoral stems: a minimum 5-year follow-up

BACKGROUND

The clinical outcomes and radiological findings for cemented titanium stems remain controversial. In 2004, we produced a straight-collared double-tapered stem made from a titanium alloy with a smooth surface for cemented total hip arthroplasty. In this study, we retrospectively examined the mid-term outcomes of this stem.

METHODS

We retrospectively reviewed 61 hips that had undergone primary cemented total hip arthroplasty with a collared smooth double-tapered titanium alloy femoral stem, after a minimum of 5 years (mean 6.1, range 5.0-7.3). Patients were evaluated preoperatively and postoperatively with the Merle d'Aubigné and Postel hip score. Radiographic examination was performed for evaluation of the cementing technique, the alignment of the stem, subsidence within the cement mantle, radiolucent lines at the cement-bone or cement-stem interface, cortical hypertrophy, and calcar resorption.

RESULTS

The clinical evaluation by the Merle d'Aubigné and Postel hip score was improved from 9.4 ± 1.9 preoperatively to 15.9 ± 1.6 at the time of final follow-up. The overall survival rate was 100% at 7 years, when radiological loosening or revision for any reasons was used as the endpoint. Five stems subsided less than 1 mm vertically. Nonprogressive radiolucence at the cement-bone interface occurred in six hips, without osteolysis. Cortical hypertrophy was observed in five hips and second-degree calcar resorption in 11 hips.

CONCLUSIONS

Our results in this study show good outcomes for cemented, collared, smooth, double-tapered titanium alloy femoral stems at a minimum follow-up of 5 years.

Long-term results of cemented total hip arthroplasty for dysplasia, with structural autograft fixed with poly-L-lactic acid screws

This study reviewed a series of cemented total hip arthroplasty (THA) for dysplasia, with structural autograft fixed with poly-L-lactic acid screws. Grafted bone union was confirmed radiologically in every case, and there were no cases of early collapse or extravasation of grafted bone. Kaplan-Meier survivorship analysis of socket revision, radiologic loosening of the socket, and the appearance of a radiolucent line greater than 1 mm in the graft-socket interface as the end points indicated survival rates of 99%, 97.1%, and 63.5% at 10 years and 96.6%, 90.2%, and 56.1% at 15 years, respectively. The results of this study indicated that poly-L-lactic acid screws are safe and useful for the fixation of acetabular bone graft concomitant to cemented THA with a careful rehabilitation program.