Biomedical subjects

P M Rozing

Publications and source records attributed to P M Rozing.

At least 19 recordsLinked to original sources

PubMed2006

Pathological muscle activation patterns in patients with massive rotator cuff tears, with and without subacromial anaesthetics.

A mechanical deficit due to a massive rotator cuff tear is generally concurrent to a pain-induced decrease of maximum arm elevation and peak elevation torque. The purpose of this study was to measure shoulder muscle coordination in patients with massive cuff tears, including the effect of subacromial pain suppression. Ten patients, with MRI-proven cuff tears, performed an isometric force task in which they were asked to exert a force in 24 equidistant intervals in a plane perpendicular to the humerus. By means of bi-polar surface electromyography (EMG) the direction of the maximal muscle activation or principal action of six muscles, as well as the external force, were identified prior to, and after subacromial pain suppression. Subacromial lidocaine injection led to a significant reduction of pain and a significant increase in exerted arm force. Prior to the pain suppression, we observed an activation pattern of the arm adductors (pectoralis major pars clavicularis and/or latissimus dorsi and/or teres major) during abduction force delivery in eight patients. In these eight patients, adductor activation was different from the normal adductor activation pattern. Five out of these eight restored this aberrant activity (partly) in one or more adductor muscles after subacromial lidocaine injection. Absence of glenoid directed forces of the supraspinate muscle and compensation for the lost supraspinate abduction torque by the deltoideus leads to destabilizating forces in the glenohumeral joint, with subsequent upward translation of the humeral head and pain. In order to reduce the superior translation force, arm adductors will be co-activated at the cost of arm force and abduction torque. Pain seems to be the key factor in this (avoidance) mechanism, explaining the observed limitations in arm force and limitations in maximum arm elevation in patients suffering subacromial pathologies. Masking this pain may further deteriorate the subacromial tissues as a result of proximal migration of the humeral head and subsequent impingement of subacromial tissues.

Aged↗

PubMed2006

Proximal migration can be measured accurately on standardized anteroposterior shoulder radiographs.

UNLABELLED: During the last decade, investigators of several studies have stressed the importance of early diagnosis and treatment of rotator cuff tears to improve outcome of surgical repair. Proximal migration of the humeral head is thought to be indicative for rotator cuff disorders. We wanted to assess the accuracy of proximal migration measurement on anteroposterior radiographs. Computed tomography scans and anteroposterior radiographs of 43 shoulders in 26 patients were taken using the same protocol. Proximal migration was measured as the acromiohumeral interval and the upward migration index. The mean absolute difference for the upward migration index was only 0.06 (standard deviation, 0.07), this was less then 5% of the mean upward migration index measured on computed tomography reformations. The correlation coefficient and Bland-Altman plot showed a strong correlation between computed tomography and radiographic measurements, especially for the upward migration index (correlation coefficient, 0.82). Our results indicate that measurement of subacromial space on anteroposterior radiographs, controlled for positioning, scaling, and individual differences by using the upward migration index, presents an accurate measurement for proximal migration. LEVEL OF EVIDENCE: Diagnostic study, Level I (testing of previously developed diagnostic criteria on consecutive patients--with universally applied reference "gold" standard). See the Guidelines for Authors for a complete description of levels of evidence.

Aged↗

PubMed2006

Subacromial space measurement: a reliable method indicating fatty infiltration in patients with rheumatoid arthritis.

Proximal migration of the humeral head is thought to indicate fatty infiltration of the rotator cuff muscles or rotator cuff tears. We sought to evaluate the influence of these rotator cuff abnormalities on the subacromial space. Using anteroposterior radiographs, ultrasound, and computed tomography, we analyzed 54 shoulders in 29 patients with rheumatoid arthritis. The upward migration index was defined as proximal migration of the humeral head relative to its size. The mean muscle density from computed tomography images was used to indicate fatty infiltration. Fatty infiltration of the infraspinatus muscle showed the strongest correlation with proximal migration. After correcting for age, cuff tears, and rheumatoid disease, the partial correlation coefficient between both remained strong. A subdivision in proximal migration is proposed to screen for rotator cuff abnormalities. A large amount of fatty infiltration was indicated by an upward migration index less than 1.25, a medium amount by an upward migration index between 1.25 to 1.35, and a small amount by an upward migration index greater than 1.35. Measurement of proximal migration using the upward migration index provides a reliable screening method indicating fatty infiltration of the rotator cuff.

Acromion↗

PubMed2006

Responsiveness of the shoulder function assessment scale in patients with rheumatoid arthritis.

OBJECTIVES: To investigate the responsiveness of the Shoulder Function Assessment scale (SFA) in patients with rheumatoid arthritis (RA). METHODS: In 35 patients with RA receiving a (peri-)articular injection because of local shoulder complaints the SFA, impact of shoulder function on activities of daily living, active shoulder range of motion (ROM), the 28 joint count Disease Activity Score (DAS28), and the Health Assessment Questionnaire (HAQ) were measured before and 4-6 weeks after treatment. Responsiveness was determined using the standardised response mean (SRM), effect size (ES), and responsiveness ratio (RR). RESULTS: Overall, significant improvement was seen according to the SFA (mean change 10.9 (95% confidence interval 6.5 to 15.3)), active shoulder ROM (except external rotation), and the impact of shoulder function on daily activities. In addition, the DAS28 and HAQ scores improved significantly. The responsiveness of the SFA was excellent, with the SRM, ES, and RR being -0.86, -1.16, and 1.28, respectively. CONCLUSIONS: In addition to its good validity and reliability, the SFA proved to have a high sensitivity to clinical changes in patients with RA who received local treatment for shoulder complaints.

Activities of Daily Living↗

PubMed2005

Pathological Teres Major activation in patients with massive rotator cuff tears alters with pain relief and/or salvage surgery transfer.

BACKGROUND: Massive rotator cuff tears impose restraints on overhand arm functionality and are often accompanied by pain. After musculotendinous Teres Major transfer, overhand arm function is generally restored and pain is reduced. The assumed mechanical abduction insufficiency and Teres Major muscle function adaptation will be experimentally verified. METHODS: Principal Teres Major muscle activation (surface IEMG averaged over 3s) is recorded for 12-24 isometric and isotonic force directions perpendicular to the 60 degrees forward flexed humerus in three conditions: prior to surgery (n = 6 patients), prior to surgery and after subacromial anaesthetic (n = 6) and post-surgery (n = 3). Principal direction and on-, offset directions were estimated. FINDINGS: Teres Major activation adapts both to pathological and post surgery conditions: the normal activation during adduction changes into activation during forward flexion or abduction. Glenohumeral stabilisation, not abduction torque, seems to be the explanation for post surgery Teres Major transfer success. INTERPRETATIONS: The pathological absence of Supraspinatus and Infraspinatus forces during forward flexion result in increased upward glenohumeral instability. The superior translations are compensated for by Teres Major activity during forward flexion. This translation-'force' function conflicts with the adduction-generating rotation-'torque' function. This may explain the pain-induced reduction of arm elevation in these patients. Musculotendinous transfer solves the force-torque conflict by changing the moment arm of the Teres Major from adduction to abduction. Teres Major can now both compensate for the loss of Supraspinatus and Infraspinatus forces needed for glenohumeral stabilisation and contribute to forward flexion of the arm.

Biomechanical Phenomena↗

PubMed2005

Bone ingrowth simulation for a concept glenoid component design.

Glenoid component loosening is the major problem of total shoulder arthroplasty. It is possible that uncemented component may be able to achieve superior fixation relative to cemented component. One option for uncemented glenoid is to use porous tantalum backing. Bone ingrowth into the porous backing requires a degree of stability to be achieved directly post-operatively. This paper investigates the feasibility of bone ingrowth with respect to the influence of primary fixation, elastic properties of the backing and friction at the bone prosthesis interface. Finite element models of three glenoid components with different primary fixation configurations are created. Bone ingrowth into the porous backing is modelled based on the magnitude of the relative interface micromotions and mechanoregulation of the mesenchymal stem cells that migrated via the bonded part of the interface. Primary fixation had the most influence on bone ingrowth. The simulation showed that its major role was not to firmly interlock the prosthesis, but rather provide such a distribution of load, that would result in reduction of the peak interface micromotions. Should primary fixation be provided, friction has a secondary importance with respect to bone ingrowth while the influence of stiffness was counter intuitive: a less stiff backing material inhibits bone ingrowth by higher interface micromotions and stimulation of fibrous tissue formation within the backing.

Cell Differentiation↗

PubMed2005

Primary Souter-Strathclyde total elbow prosthesis in rheumatoid arthritis. Surgical technique.

BACKGROUND: Total elbow arthroplasty is a well-established treatment for the painful elbow joint in patients with rheumatoid arthritis. We present the results of what we believe to be the first prospective study of the Souter-Strathclyde total elbow prosthesis. METHODS: Between June 1982 and December 2000, 204 primary total elbow prostheses were inserted in 166 patients who had rheumatoid arthritis. No patient was lost to follow-up. The mean duration of follow-up was 6.4 years. All patients were examined preoperatively, at one and two years postoperatively, and at regular intervals thereafter. RESULTS: Six of the 204 elbows had pain at rest at the time of the latest follow-up. Ten patients (ten elbows) without previous neurological symptoms had development of paresthesias in the distribution of the ulnar nerve postoperatively. Patients who had pain at rest or at night and those who had ulnar nerve symptoms preoperatively were found to have a significant chance of having the same complaints postoperatively. Pain at rest or at night and a decrease in function during the follow-up period were associated with humeral loosening. Twenty-four elbows had revision of the total elbow prosthesis because of loosening of the humeral component (ten), loosening after fracture (six), dislocation (four), infection (two), restricted range of motion (one), or fracture of the middle part of the humeral shaft, proximal to the prosthesis (one). One prosthesis was removed because of humeral loosening, and eight were removed because of deep infection. Another five prostheses were radiographically loose at the time of the latest follow-up. The rate of implant survival, according to the method of Kaplan-Meier, was 77.4% after ten years and 65.2% after eighteen years. CONCLUSIONS: Total elbow replacement is associated with a high complication rate and therefore may be warranted only for seriously disabled patients. Currently, the results associated with the Souter-Strathclyde total elbow prosthesis are comparable with the results associated with other prostheses, but loosening of the humeral component remains a concern.

Arthritis, Rheumatoid↗

PubMed2004

A new type of model-based Roentgen stereophotogrammetric analysis for solving the occluded marker problem.

Roentgen stereophotogrammetric analysis (RSA) measures micromotion of an orthopaedic implant with respect to its surrounding bone. A problem in RSA is that the markers are sometimes overprojected by the implant itself. This study describes the so-called Marker Configuration Model-based RSA (MCM-based RSA) that is able to measure the pose of a rigid body in situations where less than three markers could be detected in both images of an RSA radiograph. MCM-based RSA is based on fitting a Marker Configuration model (MC-model) to the projection lines from the marker projection positions in the image to their corresponding Roentgen foci. An MC-model describes the positions of markers relative to each other and is obtained using conventional RSA. We used data from 15 double examinations of a clinical study of total knee prostheses and removed projections of the three tibial component markers, simulating occlusion of markers. The migration of the tibial component with respect to the bone, which should be zero, for the double examination is a measure of the accuracy of algorithm. With the new algorithm, it is possible to estimate the pose of a rigid body of which one or two markers are occluded in one of the images of the RSA radiograph with high accuracy as long as a proper MC-model of the markers in the rigid body is available. The new algorithm makes RSA more robust for occlusion of markers. This improves the results of clinical RSA studies because the number of lost RSA follow-up moments is reduced.

Biomechanical Phenomena↗

PubMed2004

Influence of previous open synovectomy on the outcome of Souter-Strathclyde total elbow prosthesis.

OBJECTIVES: Open synovectomy of the elbow joint is often performed in early stages of rheumatoid arthritis. Because of poor long-term results after synovectomy, insertion of a total elbow prosthesis is commonly used as a secondary procedure. The aim of this study is to evaluate the influence of previous synovectomy on the outcome after placement of a total elbow prosthesis. METHODS: We inserted 204 primary Souter-Strathclyde total elbow prostheses for rheumatoid arthritis. Two groups could be distinguished: group A with previous synovectomy 3.9 yr (mean) before the elbow replacement (n = 33) and group B without previous synovectomy (n = 171). The mean follow-up was 5.8 yr for group A and 6.3 yr for group B. All patients were assessed clinically and radiologically before the operation, 1 and 2 years later and then at regular intervals. The effect of previous synovectomy was analysed via a Cox model and a generalized linear mixed model for binomial data with multivariate normal random effects. RESULTS: No statistically significant effect of previous synovectomy on pain, function or complaints of the ulnar nerve could be found post-operatively. The post-operative flexion was significantly higher in group B than in group A. The complication-rates were similar for both groups. The overall survival rate for respectively group A and B with revision as endpoint was 66.9% (s.e. 13.4) versus 79.6 (s.e. 4.3) after 10 yr. CONCLUSIONS: Previous synovectomy does not diminish the outcome after total elbow prosthesis in this series and could therefore be considered in early, painful stages of rheumatoid destruction of the elbow joint.

Arthritis, Rheumatoid↗

PubMed2004

Systematic review of primary total elbow prostheses used for the rheumatoid elbow.

Total elbow prosthesis (TEP) has been shown to be a viable option for treatment of the rheumatoid elbow. Many types of TEP have been studied, but the heterogeneity of the studies makes most conclusions subject to discussion. The aim of this systematic review is to show the differences between the most commonly used TEP for the destroyed rheumatoid elbow. After a search in Pubmed (NLM, Bethesda, USA) the senior author selected eight frequently used TEP: the Capitellocondylar, Coonrad-Morrey, GSB III, Kudo, Liverpool, Norway, Roper-Tuke and Souter-Strathclyde. For inclusion studies we arbitrarily formulated nine criteria, after which clearly adverse events were defined for comparison purposes. The Capitellocondylar and Souter-Strathclyde prostheses are the most-studied treatments for replacing the rheumatoid elbow. In contrast to the Capitellocondylar, the Souter-Strathclyde prosthesis showed higher loosening rates but implemented modifications of the design have reduced these rates in recent studies. Nevertheless, in relation to most other joint replacements in rheumatoid patients, all TEP still have higher complication rates. For this reason an elbow prosthesis may just be warranted in seriously disabled patients.

Arthritis, Rheumatoid↗

PubMed2004

Modular total shoulder system with short stem. A prospective clinical and radiological analysis.

Between 1994 and 2001, a short-stemmed modular shoulder prosthesis was inserted in 62 shoulders in patients with rheumatoid arthritis (RA) or osteoarthrosis (OA). We reviewed 53 patients with 60 shoulders (45 RA/15 OA) with at least 24 months follow-up. In 22 shoulders, we used a total shoulder prosthesis including a glenoid polyethylene component, whereas 38 shoulders only had a humeral component. In six shoulders, the humeral component was cemented. The average follow-up was 47 (24-99) months. There were no intraoperative complications but one wound infection and one patient with proximal migration of the humeral component. Hospital for Special Surgery Score increased from 44(19-72) to 63 (21-93) points and Shoulder Function Assessment score (SFA) from 24 (12-46) to 42 (11-66)points. The VAS score for pain at rest improved from 4.3 to 1.9. Nonprogressive radiolucent lines were seen adjacent to nine glenoid and one humeral components. Fifty-six patients were satisfied with the result.

Aged↗

PubMed2004

Effectiveness of tendon transfers for massive rotator cuff tears: a simulation study.

UNLABELLED: OBJECTIVE To determine what the most effective tendon transfer is in the case of a dysfunctional rotator cuff. DESIGN: A tendon transfer procedure of latissimus dorsi, teres major or a combination of these two to the insertions of either teres minor, infraspinatus, supraspinatus, or subscapularis is simulated using a biomechanical musculoskeletal model of the upper extremity. BACKGROUND: Massive rotator cuff tears are not easily repaired. To compensate for this loss of rotator cuff function other techniques like muscle transfers are developed. METHODS: Three range of motion tasks and six activities of daily living of 24 subjects were measured. Kinematics from these tasks were used as input to the Delft Shoulder and Elbow Model. The muscle parameters of the Delft Shoulder and Elbow Model were modified to simulate a rotator cuff tear and the ability to perform the measured tasks with and without simulated transfer procedures was checked. RESULTS: The highest improvements (28-30%, P = 0.00 ) in the ability to perform tasks were observed after a simulated tendon transfer of either both muscles or teres major alone attached to the supraspinatus or infraspinatus insertion. Although all transfer procedures produce significant improvements (P = 0.00 ), there is a significant difference between the procedures (Chi square=58.8, P = 0.00 ) dependent on attachment site. CONCLUSIONS: According to the simulation procedure used in the current study, a tendon transfer of teres major and latissimus dorsi or teres major alone to the supraspinatus insertion appears to be the most effective procedure in the case of a dysfunctional rotator cuff. Practical factors, like subacromial space, volume of the muscles and tendons, tensile properties and the ability to split the muscles, will finally determine which is the preferred transfer option.

Analysis of Variance↗

PubMed2004

Biomechanical analysis of tendon transfers for massive rotator cuff tears.

OBJECTIVE: To determine why certain tendon transfers are mechanically more effective than other tendon transfers for the treatment of a massive rotator cuff tear. DESIGN: A tendon transfer procedure of latissimus dorsi, teres major or a combination of these two to the insertions of either teres minor, infraspinatus, supraspinatus, or subscapularis is simulated using a biomechanical musculoskeletal model of the upper extremity. BACKGROUND: Massive rotator cuff tears are not easily repaired. To compensate for the loss of rotator cuff function, techniques such as muscle transfers are developed. METHODS: Three range of motion tasks were used as input to the Delft shoulder and elbow model. The muscle parameters of the Delft shoulder and elbow model were modified to simulate a rotator cuff tear. A biomechanical analysis of the transferred muscles was performed, taking outcome variables such as moment arms, muscle length and muscle force into account. RESULTS: Due to the massive rotator cuff tear, an elevation and external rotation moment is lost. When the tendon was transferred to the insertions of infraspinatus or supraspinatus, the humerus was capable of elevating and externally rotating. CONCLUSIONS: On the basis of mechanical parameters such as moment arms, muscle length and force it can be concluded that a tendon transfer of the teres major to the supraspinatus insertion will produce the best functional outcome in the treatment of massive rotator cuff tears. RELEVANCE: To find biomechanical evidence for an optimal tendon transfer that will lead to improved treatment of patients with a massive rotator cuff tear.

Biomechanical Phenomena↗

PubMed2004

Effect of glenoid component inclination on its fixation and humeral head subluxation in total shoulder arthroplasty.

OBJECTIVE: To investigate the effect of glenoid component inclination angle on the fixation of cemented glenoid-bone structures and humeral head subluxation. BACKGROUND: Results of shoulder replacements, in terms of glenoid component fixation and joint functionality, are bad and must be improved. Repeated glenoid component tilting, a result of eccentric contact forces harms glenoid component fixation. However, the effect of glenoid component inclination is unknown. METHODS: Keeled glenoid components are cemented into bone substitutes and positioned under inclination angles varying between -4.5 degrees and +4.5 degrees . For each inclination angle 5 glenoid specimens are loaded by a horizontal, constant joint compression force (725 (SD 10) N) and a vertical, superior directed subluxation force (shear force), cyclically varying between 0 and 350 (SD 1) N. After 200,000 load cycles, the upper and lower glenoid component rim-displacements are measured during 1500 additional load cycles by custom made displacement sensors. RESULTS: The maximal superior rim-displacement significantly increased and the minimal inferior rim-displacement dramatically decreased for increasing glenoid component inclination angles up to +4.5 degrees . Maximal ratio of subluxation force over compression force significantly decreased for increasing glenoid component inclination. CONCLUSIONS: According to this study, decreasing glenoid component inclination angle decreases glenoid component tilting and humeral head subluxation and the results can be used to improve total shoulder replacements. RELEVANCE: Better understanding of the effect of glenoid component inclination on glenoid component tilting and humeral head subluxation may be useful information for the surgeon to improve results of the total shoulder arthroplasty, when replacing the glenoid surface.

Arthroplasty↗

PubMed2004

Radiographic changes after resection of the distal ulna in rheumatoid arthritis.

Progressive ulnar translocation of the carpus and problems with the ulnar stump have been reported after resection of the distal ulna in rheumatoid arthritis (RA). However this has only occasionally been quantitatively assessed. In this study 24 wrists in 21 patients with RA were followed up for an average of 100 months after resection of the distal ulna. An additional 24 wrists in 14 non-operated RA patients were followed up for 92 months. In a retrospective radiographic analysis we demonstrate similar increases in ulnar translocation and ulnar-carpal distances in both groups.

Adult↗

PubMed2004

Treatment of recurrent posterior dislocation of the shoulder in cerebral palsy by injection with botulinum toxin A into the M. subscapularis.

SUBJECTS: A 20-year-old woman, known to have cerebral palsy and a spastic hemiparesis, suffered from frequent (up to 20 times a day) and painful posterior dislocation of the affected shoulder. INTERVENTIONS: For the last two years we have treated her with injections with botulinum toxin A (100 U Botox) in the M. subscapularis. RESULTS: Pain and dislocation rate have improved substantially.

Activities of Daily Living↗

PubMed2004

Evaluation of three pose estimation algorithms for model-based roentgen stereophotogrammetric analysis.

Model-based roentgen stereophotogrammetric analysis (RSA) uses a three-dimensional surface model of an implant in order to estimate accurately the pose of that implant from a stereo pair of roentgen images. The technique is based on minimization of the difference between the actually projected contour of an implant and the virtually projected contour of a model of that same implant. The advantage of model-based RSA over conventional marker-based RSA is that it is not necessary to attach markers to the implant. In this paper, three pose estimation algorithms for model-based RSA are evaluated. The algorithms were assessed on the basis of their sensitivities to noise in the actual contour, to the amount of drop-outs in the actual contour, to the number of points in the actual contour and to shrinkage or expansion of the actual contour. The algorithms that were studied are the iterative inverse perspective matching (IIPM) algorithm, an algorithm based on minimization of the difference (DIF) between the actual contour and the virtual contour, and an algorithm based on minimization of the non-overlapping area (NOA) between the actual and virtual contour. The results of the simulation and phantom experiments show that the NOA algorithm does not fulfil the high accuracy that is necessary for model-based RSA. The IIPM and DIF algorithms are robust to the different distortions, making model-based RSA a possible replacement for marker-based RSA.

Algorithms↗

PubMed2004

Effect of joint conformity on glenoid component fixation in total shoulder arthroplasty.

Results of shoulder replacements are inferior and must be improved. Two of the major problems of total shoulder replacements are loosening of cemented glenoid components and wear of polyethylene inlays of uncemented, metal-backed glenoid components. The aim of this study is to investigate the influence of joint conformity on glenoid-component fixation. Keeled glenoid components, with radii of curvature of 24, 25, or 29 mm, were cemented in bone substitutes, placed in a force-controlled test set-up, articulating against a 24 mm humeral head. They were loaded by a constant joint compression force (725 +/- 10 N) and a superior subluxation force (shear force), cyclically varying between 0 and 350 +/- 1 N. After 200,000 load cycles, the upper and lower glenoid component rim-displacements were measured by custom-made displacement sensors. Additionally, the shear-out strength has been measured to investigate the residual strength. The glenoid component structures with radii of curvature of 24, 25, and 29 mm showed maximum superior rim-displacements of 0.163 (SD = 0.01), 0.299 (SD = 0.0306), and 0.350 (SD = 0.0197) mm respectively, which is a significant difference (p < 0.05). The maximum shear-out strength of glenoid components with radii of curvature of 24, 25, and 29 mm was 2707 (SD = 452), 2648 (SD = 299), and 2631 (SD = 312) N respectively, which is not a significant difference (p < 0.05). However, the results indicate that a conform articulation shows smaller glenoid rim-displacements, which might be beneficial for long-term component fixation.

Arthroplasty↗