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Biomedical subjects

L Weidenhielm

Publications and source records attributed to L Weidenhielm.

At least 19 recordsLinked to original sources
PubMed2006

The addition of tramadol to morphine via patient-controlled analgesia does not lead to better post-operative pain relief after total knee arthroplasty.

BACKGROUND: Tramadol is used as an analgesic in post-operative pain treatment. Intravenous tramadol is often combined with morphine to achieve better pain relief and less side-effects after orthopaedic surgery. However, the available evidence is insufficient to support this combination. For this reason, we conducted the present non-commercial, randomized, double-blind clinical trial. METHOD: Sixty-three patients with osteoarthritis of the knee, selected for primary total knee arthroplasty (TKA), were randomized to receive saline or tramadol 100 mg/ml intravenously every 6 h during the first post-operative day (total, 400 mg/24 h). All patients had access to morphine via a patient-controlled analgesia (PCA) pump. RESULTS: Neither during the 6 h after the first dose nor during the first post-operative day could we detect any statistically significant difference with regard to pain intensity, sedation and nausea between patients treated with tramadol and the placebo group. However, the withdrawal rate caused by insufficient pain relief was greater in the tramadol group (7/31) than in the saline group (2/32). This difference did not reach statistical significance. In the group of patients who remained in the study for 24 h ('per protocol'), those randomized to receive tramadol had a significantly (P < 0.05) lower morphine consumption (20 mg or 31%) than the placebo group. CONCLUSION: Our study does not support the combination of tramadol and morphine via PCA for post-operative pain relief after primary TKA. In addition, our study indicates that morphine via PCA as the sole means of post-operative analgesia does not provide sufficient pain relief after TKA. Thus, other means of post-operative analgesia should be used following TKA.

Adult↗
PubMed2006

Osteoblast dysfunction in male idiopathic osteoporosis.

The etiology of primary osteoporosis in young and middle-aged men is unknown. We have studied osteoblast function in cells derived from men with idiopathic osteoporosis and in control cells from age-matched men with osteoarthrosis. Osteoblasts were isolated from transiliac bone biopsies. Osteoblast function was measured as vitamin D-stimulated osteocalcin production and production of cytokines and factors involved in osteoclast activation and bone formation. Cell proliferation was measured as (3)H-thymidine incorporation. Parathyroid hormone-related peptide (PTHrP) mRNA was measured using reverse-transcriptase polymerase chain reaction. In osteoporotic men, bone mineral density at the femoral neck was correlated to in vitro production of osteocalcin. Osteoblasts from osteoporotic men produced significantly less osteocalcin after vitamin D stimulation but had increased production of macrophage colony-stimulating factor (M-CSF) compared to controls. The osteocalcin response was negatively correlated to production of M-CSF, interleukin-6, and C-terminal propeptide of type I collagen. Basal (3)H-thymidine incorporation was similar in cells from osteoporotic patients and controls. PTHrP (10(-9 )M) significantly increased cell proliferation in control cells but not in osteoporotic cells. Basal PTHrP mRNA levels were significantly higher in osteoporotic cells than in cells from controls. The results are in agreement with previous histomorphologic studies indicating that men with idiopathic osteoporosis have an osteoblast dysfunction with decreased osteocalcin production and increased production of factors stimulating osteoclast activation. This indicates a catabolic cellular metabolic balance leading to negative bone turnover, resulting in osteoporosis. The cause of such cellular dysfunction needs further evaluation.

Adult↗
PubMed2005

Gait and clinical measurements in patients with knee osteoarthritis after surgery: a prospective 5-year follow-up study.

The aim of this prospective follow-up study was to determine if gait measurements and/or clinical measurements could detect differences in treatment outcome between two surgical interventions in patients with knee osteoarthritis (OA). The patients were followed for 5 years after surgery. Forty patients, 55-70 years of age, with unilateral knee OA were included. The patients were treated either with a high tibial osteotomy (HTO) (n=18) or a unicompartmental knee arthroplasty (UKA) (n=22). Clinical outcome measures were the British Orthopaedic Association (BOA) score, pain during walking, passive range of knee motion (PROM) and patients' subjective opinion. The gait variables were free walking speed, step frequency, step length and single and double-stance phase for each leg. The patients were examined before surgery and 3 months, 1 year and 5 years after surgery. The time-distance variables of gait could detect differences in treatment outcome, 3 months after surgery, while the clinical outcome measures, as given here, could not detect any differences between the two groups of patients. Measurements of free walking speed could be recommended for clinical evaluation, after surgical interventions, in patients with knee OA.

Aged↗
PubMed2005

Assessing wear of the acetabular cup using computed tomography: an ex vivo study.

PURPOSE: To validate a clinically useful method for measuring acetabular cup wear using computed tomography (CT). MATERIAL AND METHODS: Eight uncemented acetabular cups were scanned twice ex vivo using CT. The linear penetration depth of the femoral component head into the cup and the thickness of the remaining polyethylene liner were measured in the CT volumes using dedicated software. Two independent examiners twice assessed each volume. The CT measurements were compared to direct measurements using a coordinate measuring device and micrometer measurements. RESULTS: Accuracy of wear measurements expressed as penetration depth was +/-0.6 and +/- 1.0 mm for the two examiners, respectively, with no significant differences between examiners, trials, and CT scans. Accuracy of measurements of remaining polyethylene was +/- 1.3 and +/- 1.0 mm, respectively, for the two examiners. Systematic differences between examiners were found, but no significant differences between trials and CT scans. These differences were due to different interpretations of metal artifacts in the volumes. CONCLUSION: The proposed CT method for evaluating wear as head penetration depth allows for reliable wear detection at a clinically relevant level. Measurements of remaining polyethylene on CT volumes are not as reliable as wear measurements owing to metal artifacts.

Device Removal↗
PubMed2005

Standard orientation of the pelvis: validation on a model and ten patients.

PURPOSE: To validate an image post-processing method for re-orienting the pelvis in CT volumes to a standardized orientation in a model and in 10 patients. MATERIAL AND METHODS: Twenty-four CT volumes of a pelvic model and 10 pairs of postoperative total hip arthroplasty (THA) patient CT scans were rotated to a defined pelvic standard orientation and the rotation was recorded. For precision, a test-retest procedure was used. For accuracy, three exactly represented coordinate points were used. For clinical application, the standard orientation was used for calculating the direction of acetabular cup migration from a previous model study. RESULTS: Precision of pelvic standard orientation, calculated as maximal directional error, was better than 1 degrees in the model study and better than 1.5 degrees in the patient study. Accuracy, expressed as angle between ideal and measured coordinate axes, was 0.1 degrees for x, y, z axes. No measurable systematic errors were found. When applied to acetabular cup migration in the model, standardization of pelvic orientation had no significant effect on the measurements. CONCLUSION: Reorienting the pelvis during image post-processing was shown to be accurate. It enables measurements relative to the pelvis and minimizes the dependency of patient positioning.

Adult↗
PubMed2003

Stability of acetabular axis after total hip arthroplasty, repeatability using CT and a semiautomated program for volume fusion.

PURPOSE: To validate a CT method for detecting changes in acetabular cup orientation after THA. MATERIAL AND METHODS: 26 CT examinations were obtained from a pelvic model with an uncemented acetabular cup. The model position was altered between acquisitions, but the cup axis angle vis-à-vis the pelvis was maintained. Data sets were combined into 37 pairs, each containing a unique positioning error. The pelvi in different examinations were fused, creating transformed volumes. Landmarks corresponding to the cup before and after fusion were placed interactively by two independent examiners. The orientation of the acetabular axis was calculated for each volume and compared across volumes. RESULTS: Before fusion the mean angle error between the acetabular axes was 4.17 degrees (SD +/- 1.95 degrees ). After fusion the mean angle error was 0.36 degrees (SD +/- 0.17). The 95% repeatability limits were below 0.7 degrees. There was no significant interobserver difference. Analysis of the cup landmarking pattern by condition numbers and individual landmark errors showed stability. CONCLUSION: Non-invasive fusion of CT volumes and a stable landmarking pattern for the acetabular cup outperforms routine plain radiography in detecting changes in the orientation of the acetabular axis over time. The method delivers both visual and numerical output and could be used in clinical practice.

Acetabulum↗
PubMed2003

Model studies on acetabular component migration in total hip arthroplasty using CT and a semiautomated program for volume merging.

PURPOSE: Validation of a non-invasive CT method for detection of acetabular cup migration after total hip arthroplasty in a phantom study. MATERIAL AND METHODS: 26 CT examinations were obtained of a pelvic model while altering the position of the acetabular cup. Using a previously described program for volume merging, the pelvi in different examinations were fused and the 3D alterations of the position of the acetabular cup were evaluated visually and numerically and correlated to direct measurements on the model. RESULTS: Visually, two independent examiners differentiated between 0, 1 and 2 to 3 mm migration with 100% specificity and sensitivity. Numerically, the mean error over all cases between model and CT measurements was 0.04 mm (SD +/- 0.33). The mean absolute error between model and CT data was 0.26 mm (SD +/- 0.19). Intra- and interobserver 95% accuracy and repeatability limits were below 0.5/0.7 mm, respectively. No significant interobserver difference occurred. The data were normally distributed and not dependent on observer. CONCLUSION: The accuracy of this non-invasive method out-performs routine plain radiography. The method gives both visual and numerical correlates to migration and can be used in clinical practice.

Arthroplasty, Replacement, Hip↗
PubMed2003

Spatial component position in total hip arthroplasty. Accuracy and repeatability with a new CT method.

PURPOSE: 3D detection of centerpoints of prosthetic cup and head after total hip arthroplasty (THA) using CT. MATERIAL AND METHODS: Two CT examinations, 10 min apart, were obtained from each of 10 patients after THA. Two independent examiners placed landmarks in images of the prosthetic cup and head. All landmarking was repeated after 1 week. Centerpoints were calculated and compared. RESULTS: Within volumes, all measurements of centerpoints of cup and head fell, with a 95% confidence, within one CT-voxel of any other measurement of the same object. Across two volumes, the mean error of distance between center of cup and prosthetic head was 1.4 mm (SD 0.73). Intra- and interobserver 95% accuracy limit was below 2 mm within and below 3 mm across volumes. No difference between intra- and interobserver measurements occurred. A formula for converting finite sets of point landmarks in the radiolucent tread of the cup to a centerpoint was stable. The percent difference of the landmark distances from a calculated spherical surface was within one CT-voxel. This data was normally distributed and not dependent on observer or trial. CONCLUSION: The true 3D position of the centers of cup and prosthetic head can be detected using CT. Spatial relationship between the components can be analyzed visually and numerically.

Arthroplasty, Replacement, Hip↗
PubMed2002

Acetabular component migration in total hip arthroplasty using CT and a semiautomated program for volume merging.

PURPOSE: To develop a non-invasive method for detection of acetabular cup migration after total hip arthroplasty (THA) with a higher degree of accuracy than routine plain radiography. MATERIAL AND METHODS: Two CT examinations, 10 min apart, were obtained from each of 10 patients that had undergone THA. Using an in-house developed semiautomated program for volume merging, the pelves in the two examinations were fused and the acetabular cup was visually and numerically evaluated to test the method's accuracy in detecting migration. RESULTS: In the visual evaluation of the best match a 1-mm translation of the cup was detectable. The numerical evaluation, comparing landmarks placed in the images of the acetabular cup and the head of the femur component in the two examinations, showed the mean difference in orientation of acetabular axes to be 2.5 degrees, the mean distance between centre of cup face to be 2.5 mm and the mean distance between centre of the head of the prosthetic femoral component to be 1 mm. CONCLUSION: This method has a significantly higher accuracy than routine plain radiography in detecting acetabular cup migration and could be used in clinical practice. It gives both a visual and a numerical correlate to migration.

Algorithms↗
PubMed2001

Bracing versus nonbracing in rehabilitation after anterior cruciate ligament reconstruction: a randomized prospective study with 2-year follow-up.

This study prospectively randomized 62 patients to rehabilitation programs either with or without postoperative brace for 6 weeks following bone-tendon-bone anterior cruciate ligament reconstruction. The nonbraced group had a smaller knee circumference 2 weeks after surgery. At 6-month follow-up the nonbraced group had a better Tegner score. At 2 years there was no difference between the groups. There was one partial rupture of the graft in the nonbraced group after a new trauma 1 year after surgery. There were no differences between the groups in either subjective or objective knee stability at 2 or 6 weeks or at follow-up 3, 6, and 24 months after surgery. This study found no benefit of using a postoperative knee brace on patients' knee function at any stage up to 24 months after surgery. Furthermore, the braced group was not more stable than the nonbraced group, indicating that the brace does not contribute to a more stable knee during rehabilitation or 2-year follow-up.

Adult↗
PubMed2001

Does metal backing improve fixation of tibial component in unicondylar knee arthroplasty? A randomized radiostereometric analysis.

In a prospective, randomized study, patients with medial gonarthrosis stage I to III according to Ahlbäck were allocated to a unicondylar knee arthroplasty (Miller-Galante, Zimmer, Inc., Warsaw, IN) with an all-polyethylene tibial component or metal-backed tibial component of the same design. The purpose of the study was to evaluate if metal backing enhanced tibial component fixation. A total of 45 knees (42 patients; 23 metal-backed components and 22 all-polyethylene components) were examined. We used radiostereometric analysis to measure micromotion of the tibial component over a period of 2 years after surgery. Hospital for Special Surgery score was used for clinical evaluation. We found no statistically significant differences in clinical results or migration of the tibial component over a 2-year follow-up period. These findings do not support better fixation of metal-backed tibial components. Because of these findings, we advocate all-polyethylene tibial components in unicondylar knee arthroplasties because of optimal biomechanical strength at a given height of tibial component, avoiding potential problems of modularity and minimizing the amount of interfaces, at a lower cost.

Aged↗
PubMed2000

Can local anesthesia be recommended for routine use in elective knee arthroscopy? A comparison between local, spinal, and general anesthesia.

Local anesthesia (LA) for outpatient knee arthroscopy is not a standard procedure at most hospitals. To evaluate the LA technique for knee arthroscopy on medically healthy patients, this study compared 3 anesthesia techniques. Four hundred patients were randomized to either local (n = 200), general (n = 100), or spinal (n = 100) anesthesia. Evaluated outcomes included the patient's subjective view of the procedure, and nausea and pain at rest and during active movement. All variables were recorded perioperatively and postoperatively. In addition, the performing surgeon's opinion of the degree of patient pain and the technical difficulty of the procedure were noted. Three hundred forty-two patients completed the study. In the group receiving local anesthesia (n = 180) the median visual analog scale pain score during surgery was 6 mm (mean, 17.5; SD, 23.2; range, 0 to 100 mm). Twenty-one LA patients would have preferred another form of anesthesia. In 29 patients, LA was not considered as the optimal anesthesia by the performing surgeon. Eight LA patients agreed with the surgeon that the anesthesia method used was not optimal, of these patients, 5 had synovitis (3%). In 5% of the LA patients there were technical problems. Thus, this study shows that elective knee arthroscopy can be performed under local anesthesia in 92% of the patients from a technical point of view. Excluding patients who do not choose local anesthesia and those who have hypertrophic synovitis preoperatively, knee arthroscopies can be performed as safely and effectively under local anesthesia as under any other form of anesthesia. For most patients, local anesthesia can be recommended as the standard procedure for outpatient knee arthroscopy.

Adult↗
PubMed1999

Knee arthroscopy in local versus general anaesthesia. The incidence of rearthroscopy.

The choice of anaesthesia in routine knee arthroscopy varies considerably. Concerns about local anaesthesia include the fear that it will take longer to perform surgery and that the anaesthesia will be inadequate, leading to patient discomfort. In this study, data from all patients (n = 6519) who had undergone a knee arthroscopy at St Göran Hospital Artro Clinic, in Stockholm, Sweden, during a 3.5 year period, between January 1993 and July 1996, were reviewed. Of these 6519 primary arthroscopies, 4101 were performed under local anaesthesia and 2418 under general anaesthesia. The purpose of the study was first to identify those arthroscopies that could not be successfully performed because the local anaesthesia was inadequate, and second, to investigate if arthroscopy under local anesthesia was associated with an increased number of rearthroscopies compared to general anaesthesia. The total number of rearthroscopies, performed within 180 days from the primary arthroscopy, was 214. Of these 214 rearthroscopies, 146 were due to a new indication for surgery and 30 were due to persisting clinical symptoms (true rearthroscopies). The remaining 38 rearthroscopies were due to an incomplete examination (because of patient discomfort) in a primary procedure where local anaesthesia was used. Of the 30 true rearthroscopies, 19 originated from the 4101 primary arthroscopies performed under local anaesthesia (0.46%) and 11 originated from the 2418 primary arthroscopies performed under general anaesthesia (0.45%). It is concluded that 0.9% of the primary arthroscopies performed under local anaesthesia could not be performed safely due to patient discomfort. There was no difference in the frequency of rearthroscopy between the arthroscopies performed under local anaesthesia compared to those performed under general anaesthesia.

Adult↗
PubMed1996

Physiotherapy in knee osteoarthrosis: effect on pain and walking.

Patients with knee osteoarthrosis are often referred for physiotherapy and many different types of treatment are given. The value of many of these treatments has been questioned. This study was intended to evaluate the effect of commonly used physiotherapy treatments in a training programme on patients with medial knee osteoarthrosis, scheduled for surgery. The results from this study also provide useful data for further evaluation of different physiotherapy treatments to this patient group. Thirty-four patients were randomised to physiotherapy three times a week for 5 weeks and the other 34 received no treatment. The training programme is described in detail. The patients were evaluated by clinical examination, step test, gait analysis and isokinetic measurements of thigh muscle strength before and after treatment. The patients in the treatment group experienced a feeling of overall improvement in the knee and the ability to descend steps improved when compared to the control group. There were no significant differences in gait, range of motion or isokinetic measurements of muscle strength between the groups. We conclude that physiotherapy as given here made our patients feel better and their ability to descend stairs improved. These improvements are beneficial to the patients and support the positive effects of exercises and activity. Whilst the objective improvements were small, suggesting that this treatment may not be justified, patients in the treatment group believed that they were improved.

Aged↗
PubMed1995

Surgical correction of leg alignment in unilateral knee osteoarthrosis reduces the load on the hip and knee joint bilaterally.

Seventeen patients with strictly unilateral medial knee osteoarthrosis that justified surgical treatment constituted the study group. No patient had any symptoms from the hip or ankle joints or from the other knee. Eight patients were operated with high tibial osteotomy and nine were operated with unicompartmental prosthetic replacement (Brigham model). The forces and the external moment about the hip, knee, and ankle joints of the involved and uninvolved leg were calculated before and 1 year after corrective surgery and compared to the external moment in 10 normal controls. Clinical examinations was performed and the hip-knee-ankle angle in the involved leg was determined from whole-leg weightbearing radiographs before and 1 year after surgery. The external moments about the hip, knee, and ankle joints and the knee moment arms at mid-stance in the frontal plane during gait were determined with a Kistler force plate and a videorecording system. All patients improved clinically after surgery. The mean hip-knee-ankle angle changed from 11 degrees of varus to 0 degrees. In the uninvolved leg the mid-stance adduction moments about the hip and knee joints were significantly increased compared to normal subjects in the control group before surgery, but reduced to a normal level 1 year after surgery. This reduction was mainly due to a significant reduction of the medially directed force. The moments about the ankle joints were not found to be changed by the knee deformity or by the corrective surgery. RELEVANCE: This study demonstrates that a varus malalignment in the osteoarthrotic knee is accompanied by increased load about the uninvolved hip and knee joint. One might expect a more rapid progression of degenerative changes in joint cartilage as a consequence of such increased load. The reduced load after surgical correction of leg alignment might be beneficial to patients with osteoarthrosis of their hip and knee joints.

Journal Article↗
PubMed1995

Improvement after surgery in patients with osteoarthrosis of the knee.

To ascertain both physical and psychosocial effects of knee surgery in patients with moderate gonarthrosis, clinical examination of patients has been supplemented with a questionnaire SIP (Sickness Impact Profile) to describe the functional health status. Sixty patients, 35 women and 25 men, mean age 63 years, with moderate medial osteoarthrosis of the knee were included in the study. Sixteen patients had bilateral symptoms of gonarthrosis. Patients considered that their knee ostheoarthrosis had great influence physically as well as psychosocially. All patients graded pain during walking. Thirty-five patients were treated with a medial unicompartmental knee endoprosthesis and 25 patients were treated with a valgus osteotomy. After surgery the mean values for all measured variables were improved. Superior results were found among patients with unilateral disease compared to patients with bilateral disease. No differences in results were found between patients given different surgical treatments. The physical and psychosocial influence of osteoarthrosis of the knee were more pronounced in women. It is concluded that the SIP appears to be a measure with sufficient sensitivity to detect physical and psychosocial changes in patients with moderate osteoarthrosis of the knee.

Aged↗
PubMed1994

Adduction moment of the knee compared to radiological and clinical parameters in moderate medical osteoarthrosis of the knee.

The purpose of this study was to investigate the relationship between clinical symptoms, static radiographic measurements, and of load distribution during walking at the knee, in 54 patients with moderate medial osteoarthrosis of the knee. Varus deformity of the knee was assessed from static radiographic measurements as the Hip-Knee-Ankle (HKA) angle, and range of moments at the knee in the frontal plane were assessed using a Kistler force plate system. No correlations between clinical symptoms and radiographic parameters or moments at the knee were found. The adduction moment in mid stance was more important than the peak adduction moment in differentiating between patients and normal controls. The amplitude of the peak adduction moment depended on the sex and body mass of the patients, while the amplitude of the mid stance adduction moment depended on body mass and the varus deformity of the knee. There was a weak correlation between the peak adduction moment and the HKA-angle (r = 0.32, P < 0.05) and there was a moderately high correlation between the peak adduction moment in mid stance, i.e 50% of the stance phase, and the HKA angle (r = 0.46, P < 0.001) even after normalization of the mid stance moment to body mass. Accordingly, 20% of the medio-lateral knee load in mid stance during walking could be explained by the varus deformity of the osteoarthrotic knee in our patients.

Body Mass Index↗