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Thomas Anderson

Publications and source records attributed to Thomas Anderson.

9 recordsLinked to original sources
PubMed2005

Tibio-talocalcaneal arthrodesis as a primary procedure using a retrograde intramedullary nail: a retrospective study of 26 patients with rheumatoid arthritis.

BACKGROUND: Arthrodesis of the ankle joint using screws or external fixation is often a demanding procedure, notably in patients with rheumatoid arthritis. We investigated whether tibio-talocalcaneal arthrodesis with the use of an intramedullary nail is a safe and simple procedure. PATIENTS AND METHODS: We retrospectively reviewed 25 ankles (25 patients) at median 3 (1-7) years after tibio-talocalcaneal arthrodesis because of rheumatoid arthritis. All had been operated on by retrograde insertion of a retrograde nail. 5 types of nail had been used. Complications, functional outcome scores, and patient satisfaction were determined and the radiographs evaluated for healing. RESULTS: All but 1 ankle had a radiographically healed arthrodesis. We recorded 3 deep infections, all healed--in 2 cases after extraction of the nail--and the arthrodesis healed in all 3 patients. The average functional scores at follow-up were high, considering that the patients suffered from rheumatoid arthritis. 23 patients were satisfied with the outcome. We found a correlation between the functional scores and the general activity of the disease expressed as a Health Assessment Questionnaire score. INTERPRETATION: In patients with rheumatoid arthritis, tibio-talocalcaneal arthrodesis with a retrograde intra-medullary nail results in a high rate of healing, a high rate of patient satisfaction, and relatively few complications.

Adult↗
PubMed2005

Ankle arthrodesis by compression screws in rheumatoid arthritis: primary nonunion in 9/35 patients.

INTRODUCTION: Today, percutaneous or open arthrodesis of the ankle, using one or several screws for fixation, is a common method for treatment of the rheumatic ankle. However, there is very little information in the literature on the reliability of the method. METHODS: We performed a retrospective radiographic and clinical study on 35 ankles of 35 patients. Function was evaluated using the Mazur and AOFAS scores. For evaluation of activity of the rheumatic disease, we used the HAQ score. RESULTS: 31 ankles had healed--26 at the first attempt and 5 after repeat arthrodesis. There was no difference between 13 cases operated on percutaneously and 22 cases operated on with open technique with respect to radiographic healing. Mean AOFAS total score was 56 of possible 86 points. The AOFAS total score correlated with the severity of the rheumatic disease. 20 patients were satisfied with the result, 12 were somewhat satisfied and 3 patients were dissatisfied although the ankle in 2 of these 3 patients had fused. INTERPRETATION: The use of compression screws for fusion of the rheumatic ankle does not appear to give acceptable results regarding healing and function.

Adult↗
PubMed2004

Classification of arterial plaque by spectral analysis in remodelled human atherosclerotic coronary arteries.

We aimed to characterise and to identify the predominant plaque type in vivo using unprocessed radiofrequency (RF) intravascular ultrasound (US) backscatter, in remodelled segments of human atherosclerotic coronary arteries. A total of 16 remodelled segments were identified using a 30-MHz intravascular ultrasound (IVUS) scanner in vivo. Of these, 9 segments were classified as positively remodelled (>1.05 of the total vessel area in comparison with the proximal and distal reference segments) and 7 as negatively remodelled (<0.95 of reference segment area). Spectral parameters (maximum power, mean power, minimum power and power at 30 MHz) were determined and plaque type was defined as mixed fibrous, calcified or lipid-rich. Positively remodelled segments had a larger total vessel area (16.5 +/- 1.1 mm2 vs. 8.7 +/- 0.9 mm2, p<0.01) and plaque area (7.3 +/- 1.1 mm2 vs. 4.4 +/- 0.8 mm2, p=0.05) than negatively remodelled segments. Both positively and negatively remodelled segments had a greater percentage of fibrous plaque (p<0.01) than calcified or lipid-rich plaque. Comparing positively and negatively remodelled segments, there was no significant difference between the proportion of fibrous, calcified or lipid-rich plaque. We have been able to characterise and to identify plaque composition in vivo in human atherosclerotic coronary arteries. Our data suggest that remodelled segments are predominantly composed of fibrous plaque, as identified by RF analysis, although plaque composition is similar, irrespective of the remodelling type.

Adaptation, Physiological↗
PubMed2004

Uncemented STAR total ankle prostheses.

BACKGROUND: The feasibility of replacing the ankle joint has been a matter of speculation for a long time. In recent years, the designs of ankle prostheses have been improved, and three designs, all used without bone cement, currently dominate the market. However, documentation of the clinical results of the use of these prostheses is sparse. We reviewed the intermediate-term results of fifty-one consecutive Scandinavian Total Ankle Replacements (STAR). METHODS: Between 1993 and 1999, fifty-one consecutive ankles were replaced with an uncemented, hydroxyapatite-coated STAR total ankle prosthesis. Clinical examination for the present study was performed by one surgeon who had not taken part in the operations. Standardized radiographs were used. Complications and failures were recorded, and patient satisfaction and functional outcome scores were determined for all patients with an unrevised implant. RESULTS: Twelve ankles had to be revised. Seven were revised because of loosening of at least one of the components; two, because of fracture of the meniscus; and three, for other reasons. A component was exchanged in seven of the twelve revisions, whereas the ankle was successfully fused in the other five. An additional eight ankles had radiographic signs of loosening. The thirty-nine unrevised ankles (thirty-seven patients) were examined after thirty-six to ninety-seven months (median, fifty-two months). The patient was satisfied with the result after thirty-one of the ankle replacements, somewhat satisfied after two, and not satisfied after six. The median Kofoed score increased from 39 points before the surgery to 70 points at the time of the follow-up examination. A median follow-up score of 74 points was recorded when the system described by Mazur et al. and the AOFAS (American Orthopaedic Foot and Ankle Society) system were used. The median range of motion was approximately the same preoperatively and postoperatively. The estimated five-year survival rate, with revision for any reason as the end point, was 0.70. When radiographic loosening of either component was used as the end point, the estimated five-year radiographic survival rate was significantly better for the last thirty-one ankles treated in the series (p = 0.032). CONCLUSIONS: Total ankle replacement may be a realistic alternative to arthrodesis, provided that the components are correctly positioned and are of the correct size. However, the risks of loosening and failure are still higher than are such risks after total hip or total knee replacement.

Ankle Joint↗
PubMed2003

The sensitivity of lipid domains to small perturbations demonstrated by the effect of Triton.

The hypothesis of lipid rafts describes functional domains in biological membranes. It is often assumed that rafts form by spontaneous de-mixing of certain lipids and that they can be isolated as detergent-resistant membrane particles (DRMs) using the detergent Triton X-100 (TX). Here, we present a model that describes the process of domain formation in membranes in the presence and in the absence of TX. We measure the interactions between TX and an equimolar mixture of sphingomyelin (SM), cholesterol (Cho), and 1-palmitoyl-2-oleoyl-3-sn-glycero-phosphatidylcholine (POPC) (1:1:1, mol) by means of isothermal titration calorimetry. Comparison with pure POPC membranes reveals a very unfavorable interaction between TX and SM/Cho, which causes a substantial tendency to segregate these molecules into separate, DRM-like (SM-rich) and fluid (TX-rich), domains. If rafts are indeed formed by spontaneous de-mixing of PC and SM/Cho, they must be very sensitive, and perturbations caused by techniques used to study rafts could lead to misleading results. If, however, rafts are much more stable than PC-SM-Cho domains, there must be an unknown raft stabilizer. Subtle changes of such a promoter could serve to modulate raft function.

Animals↗
PubMed2003

Uncemented STAR total ankle prostheses. Three to eight-year follow-up of fifty-one consecutive ankles.

BACKGROUND: The feasibility of replacing the ankle joint has been a matter of speculation for a long time. In recent years, the designs of ankle prostheses have been improved, and three designs, all used without bone cement, currently dominate the market. However, documentation of the clinical results of the use of these prostheses is sparse. We reviewed the intermediate-term results of fifty-one consecutive Scandinavian Total Ankle Replacements (STAR). METHODS: Between 1993 and 1999, fifty-one consecutive ankles were replaced with an uncemented, hydroxyapatite-coated STAR total ankle prosthesis. Clinical examination for the present study was performed by one surgeon who had not taken part in the operations. Standardized radiographs were used. Complications and failures were recorded, and patient satisfaction and functional outcome scores were determined for all patients with an unrevised implant. RESULTS: Twelve ankles had to be revised. Seven were revised because of loosening of at least one of the components; two, because of fracture of the meniscus; and three, for other reasons. A component was exchanged in seven of the twelve revisions, whereas the ankle was successfully fused in the other five. An additional eight ankles had radiographic signs of loosening. The thirty-nine unrevised ankles (thirty-seven patients) were examined after thirty-six to ninety-seven months (median, fifty-two months). The patient was satisfied with the result after thirty-one of the ankle replacements, somewhat satisfied after two, and not satisfied after six. The median Kofoed score increased from 39 points before the surgery to 70 points at the time of the follow-up examination. A median follow-up score of 74 points was recorded when the system described by Mazur et al. and the AOFAS (American Orthopaedic Foot and Ankle Society) system were used. The median range of motion was approximately the same preoperatively and postoperatively. The estimated five-year survival rate, with revision for any reason as the end point, was 0.70. When radiographic loosening of either component was used as the end point, the estimated five-year radiographic survival rate was significantly better for the last thirty-one ankles treated in the series (p = 0.032). CONCLUSIONS: Total ankle replacement may be a realistic alternative to arthrodesis, provided that the components are correctly positioned and are of the correct size. However, the risks of loosening and failure are still higher than are such risks after total hip or total knee replacement.

Adult↗
PubMed2002

The overlap of amyotrophic lateral sclerosis and frontotemporal dementia.

Patients with frontotemporal dementia (FTD) with no known diagnosis of ALS or family history of ALS were clinically and electrophysiologically assessed for the presence of ALS. Of 36 patients studied, five met criteria for a definite diagnosis of ALS and two had EMG findings suggestive of denervation in one limb. An additional five patients had prominent fasciculations and six other patients had trouble swallowing but all had normal results on EMG studies. One of the patients with fasciculations and a normal EMG study progressed to definite ALS over the course of 1 year.

Adult↗
PubMed2002

Arthrodesis of the ankle for non-inflammatory conditions--healing and reliability of outcome measurements.

This is a retrospective study of 30 consecutive primary ankle arthrodeses in 29 patients with osteoarthrosis, operated on in our hospital between 1984 and 1994. Two different techniques were utilized: internal fixation with screws or external fixation using Charnley or Hoffman frames. Only 25 ankles in 24 patients were available for clinical examination. They were examined by two independent surgeons on an average of 51 months after surgery (13 to 187 months). Two radiologists separately examined the radiographs that were available--in this case, 29 ankles, without knowledge of clinical data, and 26/29 (89%) were unanimously considered as fused. This is comparable with what is reported in other series. Unanimity among all four observers regarding healing of the arthrodesis occurred in 20/25 ankles (80%). We consider that both a radiological and a clinical evaluation is important for a fair judgement of fusion. We found high consistency among the observers with respect to the clinical scores. However, the consistency was somewhat better for the Mazur than for the Kofoed system.

Adult↗