Biomedical subjects

D Rosenbaum

Publications and source records attributed to D Rosenbaum.

At least 19 recordsLinked to original sources

PubMed2006

Comparison of capacitive versus resistive joint contact stress sensors.

Cartilage contact stress elevations might be associated with pain or other symptoms after malunited, incongruous intraarticular fractures. Studies identifying fractures with patterns of elevated contact stresses would help to ensure more appropriate choices of treatment. However, appropriate instrumentation for such studies is crucial. We tested two such systems, one capacitive and one resistive, under identical loading conditions presumed to occur in the ankle. We used a materials testing machine and customized-loading fixtures to measure force detection error, contact area error, repeatability, homogeneity, creep, and one-axis and two-axis bending artifacts. The loading regimen caused pressures up to 2.5 MPa. An error in force detection between -3% and +5% was observed with the capacitive sensor whereas an error between -12% and +20% was observed with the resistive sensor. Repeatability and homogeneity were greater for the capacitive sensor. Errors in contact area measurement were less than 2% for the resistive sensor and less than 6% for the capacitive sensor. The resistive sensor could not conform to spherical surfaces without crinkling. Creep artifact was observed with both sensors. We concluded that the capacitive sensor had superior performance even though its thickness and high compliance may be disadvantageous in intraarticular measurements. The resistive sensor is required for use where higher pressures are expected despite its inferior accuracy.

Ankle Joint↗

PubMed2006

MR imaging anatomy in neurodegeneration: a robust volumetric parcellation method of the frontal lobe gyri with quantitative validation in patients with dementia.

BACKGROUND AND PURPOSE: Brain volumetry is widely used for evaluating tissue degeneration; however, the parcellation methods are rarely validated and use arbitrary planes to mark boundaries of brain regions. The goal of this study was to develop, validate, and apply an MR imaging tracing method for the parcellation of 3 major gyri of the frontal lobe, which uses only local landmarks intrinsic to the structures of interest, without the need for global reorientation or the use of dividing planes or lines. METHODS: Studies were performed on 25 subjects--healthy controls and subjects diagnosed with Lewy body dementia and Alzheimer disease--with significant variation in the underlying gyral anatomy and state of atrophy. The protocol was evaluated by using multiple observers tracing scans of subjects diagnosed with neurodegenerative disease and those aging normally, and the results were compared by spatial overlap agreement. To confirm the results, observers marked the same locations in different brains. We illustrated the variabilities of the key boundaries that pose the greatest challenge to defining consistent parcellations across subjects. RESULTS: The resulting gyral volumes were evaluated, and their consistency across raters was used as an additional assessment of the validity of our marking method. The agreement on a scale of 0-1 was found to be 0.83 spatial and 0.90 volumetric for the same rater and 0.85 spatial and 0.90 volumetric for 2 different raters. The results revealed that the protocol remained consistent across different neurodegenerative conditions. CONCLUSION: Our method provides a simple and reliable way for the volumetric evaluation of frontal lobe neurodegeneration and can be used as a resource for larger comparative studies as well as a validation procedure of automated algorithms.

Aged↗

PubMed2005

Plantar sensitivity, foot loading and walking pain in rheumatoid arthritis.

OBJECTIVE: The aim of the present study was to investigate the tactile sensitivity of the plantar surface in rheumatoid feet and its relationship to walking pain and plantar foot loading characteristics. METHODS: In 25 patients with rheumatoid arthritis (RA) and 21 healthy controls, Semmes-Weinstein monofilaments were used to assess tactile sensitivity in six foot regions. Walking pain was examined clinically. Pedography was used to analyse foot loading parameters during barefoot walking. RESULTS: In RA patients, plantar sensitivity was significantly decreased under all foot regions examined compared with the control group (P<0.05). A loss of protective sensation was found in a total of 10 regions in seven patients but not in the control group. In the RA patients, foot loading was reduced in the hindfoot (P<0.05) but was slightly increased in the forefoot (not significant). Average walking pain was 3.8 +/- 2.1 on a scale from 0 to 10 but did not correlate with the sensitivity levels. CONCLUSION: In patients with RA, no direct relationship between pain intensity and plantar foot loading was found. The decreased tactile sensitivity may be indicative of a disturbed sensation for high plantar pressures. Therefore, pedography can be useful as an additional tool in the detection of excessive forefoot loading before complications are manifested.

Adult↗

PubMed2005

[Clinical gait analysis].

Clinical gait analysis comprises a well defined repertoire of various methods for valid and reliable assessment. The rapid development of corresponding hardware and software has substantially decreased the efforts necessary for data processing and has promoted the clinical applicability of the procedures. The clinical question defines the amount of methodological input. Clinical gait analysis may provide diagnostic insight into the pathobiomechanics and the pathophysiology of complex gait disorders for which a profound understanding of the underlying causes is a prerequisite for adequate treatment. The methods may help in the screening of gait function following reconstructive surgery as a measure of quality control, the assessment of the severity of a gait disturbance, the evaluation of a rehabilitation process, or the quantification of the effect of orthoses, insoles or specific shoe ware. Simple procedures of gait analysis may suffice to obtain information on gait function which can not be derived by mere clinical observation and which can be incorporated into a clinical concept.

Activities of Daily Living↗

PubMed2004

Clinical and functional comparison of uni- and bicondylar sledge prostheses.

The aim of the present study was the evaluation of differences in clinical results, proprioceptive performance and gait in patients with unicondylar and bicondylar sledge prostheses of the knee. In a retrospective study, 17 patients with unicondylar sledge prostheses were compared with 15 patients with bicondylar sledge prostheses. Clinical examination was rated using HSS, Knee Society, and patellar scores and a visual analogue scale for pain. Proprioceptive performance was examined using sway measurements during single leg stance on a force platform. In addition, the patients underwent 3-D gait analysis including measurements of ground reaction forces and surface electromyographic (EMG) investigation of the lower extremity. Comparing both patient groups in clinical scores, gait, EMG and proprioception, no significant differences were found. Implantation of bicondylar sledge prostheses retaining both cruciate ligaments achieves functional results as good as unicompartmental arthroplasty. The presented results might encourage future research on new models of total joint replacement with preservation of both cruciate ligaments.

Aged↗

PubMed2004

Clinical and functional comparison of bicondylar sledge prostheses retaining all ligaments and constrained total knee replacement.

OBJECTIVE: Comparison of different total knee replacements regarding clinical and functional differences with respect to gait and electromyographic analyses. DESIGN: Retrospective, comparative, clinical and functional study. METHODS: Three groups (control group of 11 healthy subjects, 15 patients with bicondylar sledge prostheses retaining all ligaments (cemented unicondylar prostheses in both the medial and lateral compartment), 15 patients with constrained total knee replacement sacrificing all cruciate and collateral ligaments (cemented total knee prosthesis with intramedullary stems and a large intercondylar tibial post) were compared by clinical evaluation using a number of clinical evaluation scores, a pain scale, surface electromyographic examinations of the lower limb, and gait analysis. RESULTS: Clinical scores revealed significantly worse results for patients with constrained prostheses. Both patient groups had significantly lower clinical scores compared to the control group. Gait analysis and electromyographic parameters revealed no significant differences between both patient groups. Compared to the control group, patients revealed significantly impaired parameters. Electromyography also demonstrated significant differences between patients and controls: mean electromyographic activities were reduced in vastus medialis and lateralis, semitendinosus, tibialis anterior and gastrocnemius. Peak activities were reduced in all muscles but rectus femoris. CONCLUSION: Clinical scores demonstrated significantly better results in bicondylar sledge than in constrained prostheses. Nevertheless, gait and electromyographic analyses did not reveal significant differences. RELEVANCE: Retaining of ligaments in bicondylar sledge prostheses apparently improved the activities of daily living but is not reflected in gait and electromyographic parameters.

Arthroplasty, Replacement, Knee↗

PubMed2004

[Severe pleuropericarditis induced by long-term bromocriptin therapy, report of a case and review of the literature].

INTRODUCTION: Bromocriptin, member of the class of ergolines, is commonly prescribed as treatment of Parkinson's disease. Apart from vascular, digestif, neurologic and psychic disorders, the authors report cases of retroperitoneal fibrosis and pleural effusion, as adverse reactions related to the bromocriptin. SYNTHESIS: About 40 cases of skin, pleural, lung and retroperitoneal attacks were described after long term and high doses of bromocriptin. More ten years ago, the first case of constrictive pericarditis was cited in the medical literature, and the bromocriptin was incriminated as responsible. Since then, two other cases were cited. Our observation is a constrictive pericarditis, found in a 72 years old patient treated with bromocriptin for Parkinson's disease since five years (cumulative dose intake 73 grams). Investigations aimed to establish etiology were negative. Bromocriptin is suspected and the treatment is discontinued. As in the three other cases, cardiac and neurologic conditions markedly improved after bromocriptin's withdrawal. A pericardic thickening persists at the echography. CONCLUSION: The responsibility of bromocriptin in the etiology of constrictive pericarditis is seldom discussed, because it remains an exclusion diagnosis. Periodic chest X-ray and echocardiography should be considered in patients with long-term bromocriptin treatment.

Aged↗

PubMed2004

Influence of hamstring lengthening on muscle activation timing.

The purpose of this study was to describe the changes in muscle activation patterns using surface electromyography (sEMG) during walking in patients with cerebral palsy (CP), before and after hamstring lengthening. In the current clinical use of sEMG during walking in CP for pre-operative planning, various authors have observed that timing of muscle activation patterns hardly changes after surgical intervention. This observation is based on tendon transfer studies and visual interpretation of raw EMG signals. Little is known about the effect of muscle lengthening on muscle activation patterns of the lengthened muscles and their antagonists. Fifteen children with CP comprising a total of 23 hamstring lengthenings were included in this study. Surface EMG of semitendinosus and vastus lateralis was measured before and after surgery. Timing parameters of the sEMG patterns were quantified, using an objective burst detection algorithm and statistically evaluated. Results showed that hamstring lengthening causes statistically significant differences in timing of both the semitendinosus and vastus lateralis. It is concluded that timing parameters of operated muscles and their antagonists after surgery do change. The delayed off-time of the semitendinosus and the decreased burst duration of the antagonist (the vastus lateralis) after surgery were the most important changes.

Adolescent↗

PubMed2004

Reconstruction of the lateral ligaments: do the anatomical procedures restore physiologic ankle kinematics?

BACKGROUND: If conservative therapy fails, the standard treatment for chronic ankle instability is surgical reconstruction of the lateral ligaments. For the last seventy years, the tenodesis principles have been used for reconstruction. Recently however, surgical reconstructions--respecting the intact joint anatomy--have been developed, thus called "anatomical reconstruction principles". METHODS: This study focused on the investigation of the range of motion of the ankle and the subtalar joint following anatomical reconstruction surgery. Three different types of anatomical reconstruction procedures were compared: Direct ligament repair, tendon graft and carbon-fiber implant. RESULTS: All procedures restored the original range of motion of the subtalar joint, except for the plantarflexed/dorsiflexed positions. As for the talocrural joint, the tendon graft and the carbon fiber implant left a small laxity for movements of inversion/eversion and internal/external rotation. The direct repair procedure achieved a more accurate result and restored the physiologic kinematics almost completely. During each procedure the insertion points and the direction of the original ligaments were maintained. However, the different results for the procedure of direct ligament repair compared to the other two anatomical reconstruction procedures showed that this condition alone is not sufficient to perfectly restore the kinematics of the talocrural and subtalar joints. It is important to note that none of the procedures caused a restriction of the range of motion. CONCLUSIONS: The maintenance of the range of hindfoot motion decreases the risk of osteoarthritis as well as chronic pain or problems for the patient to walk on uneven surface. Therefore, we believe that standard therapy for chronic instability of the ankle should include direct surgical reconstruction of the ligaments. If this direct procedure cannot be performed because of poor quality of the ligaments an alternative anatomical reconstruction procedure should be considered.

Aged↗

PubMed2003

[Periodic paralysis discovered in a 65-year-old woman: one case report].

INTRODUCTION: Familial hypokalemic periodic paralysis (FHPP) is an autosomal dominant disorder which usually begins before thirty years. EXEGESIS: We report a case of FHPP occurring in a 65-year-old woman whereas two members of her family have symptoms since childhood. Differential diagnosis are discussed. CONCLUSION: FHPP must be one of the differential diagnoses in front of an hypokalemic paralysis attack, even in the elderly.

Age Factors↗

PubMed2003

Clinical and functional outcome of the Thrust Plate Prosthesis: short- and medium-term results.

OBJECTIVES: The purpose of this study was to objectively assess the functional outcome after implantation of a Thrust Plate Prosthesis. DESIGN: This retrospective study compared the gait patterns of 33 patients to a control group. BACKGROUND: Few studies have been published about this type of prosthesis describing clinical and radiographic outcome. Even though the evaluation of the functional outcome is a commonly accepted way to measure the success of an implant it has not been reported in previous studies. METHODS: Beside clinical (SF-36, and Harris Hip Score) and radiographic evaluation subjects were examined by three dimensional gait analysis and surface electromyography from seven leg and trunk muscles bilaterally. RESULTS: The average Harris Hip Score was 85.7 points, and the SF-36 only differed significantly from controls regarding physical functioning. The radiography showed considerable radiolucencies under the Thrust Plate. Kinematic parameters indicated a slight impairment of the operated limb. The analysis revealed a decreased hip (28.2%) and knee (51.2%) range of motion during gait. The joint moments on the operated side were reduced in hip (72%) and knee abduction (59%) in comparison to controls. The average electromyographic parameters indicated a significantly higher mean and peak amplitude of the tensor fasciae latae (mean 56%, peak 54%), and gluteus medius (mean 33%, peak 21%) and a lower peak activity of the gluteus maximus (19%). CONCLUSIONS: The results indicate a generally good functional outcome even though a slightly asymmetrical loading was observed. No major limitations in physical functioning and health-related quality of life was seen. The radiographic signs of loosening might indicate difficulties in achieving the proximal load transfer of this implant. RELEVANCE: The data provided in this study may serve to establish the Thrust Plate Prosthesis as an alternative procedure in total hip replacement in younger patients.

Activities of Daily Living↗

PubMed2003

[Influence of density of pressure sensors on parameters of plantar foot load--a pedographic comparison of 2pressure distribution recording platforms].

The present study aimed to establish whether a higher sensor density of 9 as compared with 4 sensors per cm2 would influence plantar pressure measurements. Twenty-seven subjects aged between 2 and 33 years were studied during free barefoot walking on an ST-4 and an ST-9 platform (Novel GmbH Munich). Most significant differences were seen in peak pressure values and contact areas of selected foot regions. However--with the exception of the toes--the differences were below 10%, so that they were not considered to be clinically relevant. Furthermore, the differences between the platforms revealed no age-related effects, so that the higher sensor density did not provide any further gain, even for the smaller feet of children.

Adolescent↗

PubMed2003

Quality of life and gait after unicondylar knee prosthesis are inferior to age-matched control subjects.

OBJECTIVE: Evaluation of quality of life, gait pattern, and muscle activity after implantation of unicondylar sledge prostheses in comparison with control group. DESIGN: A total of 17 patients were examined at an average follow-up of 21.5 mo after implantation of unicondylar sledge prostheses. In addition to clinical evaluation with different scores, our patients underwent three-dimensional gait analysis and surface electromyographic investigation of the lower limb and quality-of-life assessment using the Short Form-36 health questionnaire. The control group consisted of 11 healthy subjects. RESULTS: Statistical analysis showed significantly lower results for the patient group in the Hospital for Special Surgery score, the Knee Society score, the patella score, and the Visual Analog Scale for pain. In quality of life, significant differences could be found for the following items: physical functioning, role limitation because of physical problems, and bodily pain. Electromyographic activities during gait were significantly lower in the patient group, except for the rectus femoris and the tibialis anterior. Regarding gait analysis, the variables for ground reaction forces and stride length differed significantly, whereas maximum knee extension and flexion did not. CONCLUSIONS: Unicondylar knee replacement has failed to restore functional capabilities, quality of life, gait pattern, and muscle activity compared with healthy subjects of the same age. The assumption that unicondylar sledge prostheses preserve normal joint function must be questioned.

Aged↗

PubMed2002

[What influence do size and placement of patella resurfacing have on knee endoprosthesis?].

The aim of this study was to document the changes in retropatellar pressure, contact area and forces due to different sizes and placement of the patella resurfacing in knee arthroplasty. Six cadaver specimens (after Thiel fixation) were examined after the implantation of the total knee arthroplasty Genesis I. The patella sizes "small" and "medium" were placed as the "onlay" version, centered as well as off-centered by 0.4 cm in all four directions. Pressure and area measurements were done with Fuji pressure measuring film, which was placed between the patellar fascia of the femur and the patella in a defined position. The pressure was measured by applying a predetermined force for 5 s. The examinations were done with 60 degrees knee flexion and a force of 280 N. In our results there were no significant differences between, patella sizes. No significant differences for the medial, distal and proximal placement were found for the small patella. The lateral placement led to a significant decrease in the contact area (P = 0.0277), maximum pressure (P = 0.0422) and force (P = 0.0277). The average pressure did not change significantly (P = 0.1159). For the medium size patella there were no significant differences for medial or distal placement. The comparison of lateral and central placement revealed a significant decrease in the contact area (P = 0.0446). Comparing distal and proximal positioning, a significant increase in contact area and significant decrease in force were found (P = 0.0277 and P = 0.0277 respectively). In conclusion, the choice of small or medium patella resurfacing does not seem to have a significant influence. In comparison to the results without patella implants, the implantation of the small patella caused a significant decrease in the retropatellar contact area (P = 0.03) and force (P = 0.03). Average and maximum pressure did not change significantly (P = 0.6 and P = 0.35) even though pressure increased slightly. For the medium size, maximum pressure (P = 0.03) increased significantly and force decreased significantly (P = 0.0277) whereas contact area and average pressure increased slightly. The results of the different placements of the patella implant do not support the recommendation for a medial shift. However, at least the lateralized implantation led to a reduction of contact area and force as well as to a slight increase of pressure which is considered as unfavorable.

Aged↗

PubMed2002

Proprioceptive function, clinical results, and quality of life after unicondylar sledge prostheses.

OBJECTIVE: Evaluation of proprioceptive performance and quality of life after implantation of unicondylar sledge knee prostheses in comparison with normal control subjects. DESIGN: A total of 17 patients were examined after implantation of unicondylar sledge prostheses. Clinical examination was performed, quality of life was assessed, and proprioceptive performance was examined. A total of 11 healthy subjects of comparable age served as a control group. RESULTS: Clinical results of both groups differed significantly in all categories. Quality-of-life assessment differed only in the following items: physical functioning, role limitation caused by physical problems, and bodily pain. Other than angle reproduction at 15 degrees, no significant differences in proprioceptive testing, neither sway measurement nor angle reproduction, were found. Statistical analysis revealed no correlation between clinical scores and proprioceptive results. CONCLUSIONS: In comparison with normal control subjects of comparable age, the implantation of unicondylar sledge prostheses does not result in proprioceptive deficits. Except for physical functioning, role limitations caused by physical problems and bodily pain, most aspects of quality of life do not differ between patients and control subjects, although the patients' clinical results were significantly lower than the controls.

Aged↗

PubMed2002

[Correlation of electromyography and clinical results after bicondylar knee joint prosthesis implantation].

AIM OF THE STUDY: To investigate clinical findings in patients receiving bicondylar sledge prostheses, and their correlation with electromyographic measurements in comparison with healthy volunteers. MATERIAL AND METHODS: An average of 31.9 months after implantation of a bicondylar sledge prosthesis, 15 patients were clinically examined and compared with 11 control subjects. Electromyographic measurements of the rectus femoris, vastus medialis and lateralis, semitendinosus, biceps femoris, tibialis anterior, and gastrocnemius muscles were obtained. RESULTS: All clinical scores were significantly poorer in the patient group. The activity of the vastus lateralis was significantly reduced. The activity in the lower leg of the operated side was significantly higher than in the control group. Significant differences were found in the tibialis anterior and gastrocnemius muscles between controls and patients. Analysis of the correlation between the clinical scores and the electromyographic measurements showed no significance. CONCLUSION: The clinical results correlated only slightly with the electromyographic activity of the muscles investigated. The commonly presumed quadriceps insufficiency was not confirmed.

Aged↗

PubMed2001

[Clinico-functional results of constrained knee endoprostheses].

AIM OF THE STUDY: To assess the clinical and functional outcome after implantation of a constrained knee arthroplasty. MATERIAL AND METHODS: 14 patients with a revision of the primary prostheses with constrained knee arthroplasties ("Genesis constrained" and "Blauth") were evaluated in the operated and non operated leg at an average follow-up of 8.5 months (range 6.5 to 61.4 months). The study included clinical examinations as well as gait analysis and surface electromyography. The results were compared with a group of healthy volunteers. The clinical examinations were scored with the HSS, the Knee Society Score, the Tegner Activity Score, the Patella Score and the Visual Analogue Scale. Gait analysis was performed with a three dimensional motion analysis system. Surface electromyography was evaluated bilaterally from the rectus femoris, vastus medialis and lateralis, semitendinosus, biceps femoris (long head), tibialis anterior and gastrocnemius (medial head). RESULTS: The comparison between the healthy volunteers and the patients showed significant functional deficits in the patient group. The electromyography demonstrated significantly lower peak amplitudes in 5 of 7 muscles. In all parameters--except for knee extension--gait analysis resulted in significant differences between the patient and control group. The comparison between the operated and non operated leg showed a significant difference only for knee extension. The patients revealed a bilateral functional deficit so that gait symmetry was preserved. CONCLUSION: The presented results indicate that the functional deficits may be caused by preoperative deficits and are not only due to the operation. It can be supposed that the gastrocnemius is more important because of the high correlation with the clinical results. The value of pre- and postoperative rehabilitation programs to prevent postoperative functional deficits can be concluded.

Aged↗

PubMed2001

[Intra-articular and plantar pressure distribution of the ankle joint complex in relation to foot position].

Ankle injuries are often followed by degenerative changes in the hindfoot joints. Knowledge about the pressure distribution of the intact ankle joint may help to understand the mechanisms leading to cartilage damage. Therefore, we determined the intraarticular and plantar pressure distribution of the ankle joint complex and the Chopart joints with varying foot positions. 12 human lower leg specimens were axially loaded in a foot-loading simulator with full body weight (600 N). A capacitive pressure distribution platform was used to determine plantar pressure patterns. The intraarticular loading situation was measured with Fuji Prescale film. 3 different foot positions (neutral, 10 degrees dorsiflexion, 10 degrees plantarflexion) were investigated. Dorsiflexion led to an increase of the intraarticular contact area, force and mean pressure in the hindfoot. Plantarflexion instead increased loading in the Chopart joints. In the plantar pressure distribution force and peak pressure under the hindfoot increased with dorsiflexion. With plantarflexion area, force and peak pressure under mid- and forefoot increased. With our study we could demonstrate that the loading situation of the ankle joint complex is significantly influenced by the foot position. These findings may help to understand the development and localisation of arthritic changes due to posttraumatic changes of the joint loading characteristics.

Ankle Injuries↗