Analog Computer Research

Contains reports on three research projects

Clinical and radiological evaluation of Trabecular Metal and the Smith–Robinson technique in anterior cervical fusion for degenerative disease: a prospective, randomized, controlled study with 2-year follow-up

A prospective, randomized, controlled study was carried out to compare the radiological and clinical outcomes after anterior cervical decompression and fusion (ACDF) with Trabecular Metal™ (TM) to the traditional Smith–Robinson (SR) procedure with autograft. The clinical results of cervical fusion with autograft from the iliac crest are typically satisfactory, but implications from the donor site are frequently reported. Alternative materials for cervical body interfusion have shown lower fusion rates. Trabecular Metal is a porous tantalum biomaterial with structure and mechanical properties similar to that of trabecular bone and with proven osteoconductivity. As much as 80 consecutive patients planned for ACDF were randomized for fusion with either TM or tricortical autograft from the iliac crest (SR) after discectomy and decompression. Digitized plain radiographic images of 78 (98%) patients were obtained preoperatively and at 2-year follow-up and were subsequently evaluated by two senior radiologists. Fusion/non-fusion was classified by visual evaluation of the A–P and lateral views in forced flexion/extension of the cervical spine and by measuring the mobility between the fused vertebrae. MRI of 20 TM cases at 2 years was successfully used to assess the decompression of the neural structures, but was not helpful in determining fusion/non-fusion. Pain intensity in the neck, arms and pelvis/hip were rated by patients on a visual analog scale (VAS) and neck function was rated using the Neck Disability Index (NDI) the day before surgery and 4, 12 and 24 months postoperatively. Follow-ups at 12 and 24 months were performed by an unbiased observer, when patients also assessed their global outcome. Fusion rate in the SR group was 92%, and in the TM group 69% (P < 0.05). The accuracy of the measurements was calculated to be 2.4°. Operating time was shorter for fusion with TM compared with autograft; mean times were 100 min (SD 18) and 123 min (SD 23), respectively (P = 0.001). The patients’ global assessments of their neck and arm symptoms 2 years postoperatively for the TM group were rated as 79% much better or better after fusion with TM and 75% using autograft. Pain scores and NDI scores were significantly improved in both groups when compared with baseline at all follow-ups, except for neck pain at 1 year for the TM group. There was no statistically significant difference in clinical outcomes between fusion techniques or between patients who appeared radiologically fused or non-fused. There was no difference in pelvic/hip pain between patients operated on with or without autograft. In our study, Trabecular Metal showed a lower fusion rate than the Smith–Robinson technique with autograft after single-level anterior cervical fusion without plating. There was no difference in clinical outcomes between the groups. The operative time was shorter with Trabecular Metal implants

Effect of circadian rhythm, age, training and acute lameness on serum concentrations of cartilage oligomeric matrix protein (COMP) neo-epitope in horses

Molecular serum markers that can identify early reversible osteoarthritis (OA) in horses are lacking. Objectives: We studied serum concentrations of a novel cartilage oligomeric matrix protein (COMP) neo-epitope in horses subjected to short-term exercise and with acute lameness. The effects of circadian rhythm and age were also evaluated. Study design: Longitudinal studies in healthy horses and cross-sectional comparison of lame and non-lame horses. Methods: Sera were collected from five horses before and after short-term interval exercise and during full-day box rest. Sera from 32 acutely lame horses were used to evaluate age-related effects. Independent samples from control horses (n = 41) and horses with acute lameness (n = 71) were included. COMP neo-epitope concentrations were analysed using custom-developed inhibition ELISAs validated for equine serum. The presence of COMP neo-epitope was delineated in healthy and osteoarthritic articular cartilage with immunohistochemistry. Results: COMP neo-epitope concentrations decreased after speed training but returned to baseline levels post-exercise. No correlations between age and serum COMP neo-epitope concentrations were found (r = 0.0013). The mean (±s.d.) serum concentration of COMP neo-epitope in independent samples from non-lame horses was 0.84 ± 0.38 μg/mL, and for lame horses was 5.24 ± 1.83 μg/mL (P<0.001). Antibodies against COMP neo-epitope did not stain normal articular cartilage, but intracytoplasmic staining was found in superficial chondrocytes of mild OA cartilage and in the extracellular matrix of moderately osteoarthritic cartilage. Main limitations: ELISA was based on polyclonal antisera rather than a monoclonal antibody. There is a sex and breed bias within the groups of horses, also it could have been of value to include horses with septic arthritis and tendonitis and investigated joint differences. Conclusions: This COMP neo-epitope can be measured in sera, and results indicate that it could be a biomarker for pathologic fragmentation of cartilage in connection with acute joint lameness.Western Region Research Funding (ALF GBG‐716171), the Swedish‐Norwegian Foundation for Equine Research (H0947014), Swedish Research Council grant (VR 2015‐02959) and the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS 221‐2013‐317) supported this research.Peer Reviewe

Health problems and disability in long-term sickness absence: ICF coding of medical certificates

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to test the feasibility of International Classification of Functioning, Disability and Health (ICF) and to explore the distribution, including gender differences, of health problems and disabilities as reflected in long-term sickness absence certificates.</p> <p>Methods</p> <p>A total of 433 patients with long sick-listing periods, 267 women and 166 men, were included in the study. All certificates exceeding 28 days of sick-listing sent to the local office of the Swedish Social Insurance Administration of a municipality in the Stockholm area were collected during four weeks in 2004-2005. ICD-10 medical diagnosis codes in the certificates were retrieved and free text information on disabilities in body function, body structure or activity and participation were coded according to ICF short version.</p> <p>Results</p> <p>In 89.8% of the certificates there were descriptions of disabilities that readily could be classified according to ICF. In a reliability test 123/131 (94%) items of randomly chosen free text information were identically classified by two of the authors. On average 2.4 disability categories (range 0-9) were found per patient; the most frequent were 'Sensation of pain' (35.1% of the patients), 'Emotional functions' (34.1%), 'Energy and drive functions' (22.4%), and 'Sleep functions' (16.9%). The dominating ICD-10 diagnostic groups were 'Mental and behavioural disorders' (34.4%) and 'Diseases of the musculoskeletal system and connective tissue' (32.8%). 'Reaction to severe stress and adjustment disorders' (14.7%), and 'Depressive episode' (11.5%) were the most frequent diagnostic codes. Disabilities in mental functions and activity/participation were more commonly described among women, while disabilities related to the musculoskeletal system were more frequent among men.</p> <p>Conclusions</p> <p>Both ICD-10 diagnoses and ICF categories were dominated by mental and musculoskeletal health problems, but there seems to be gender differences, and ICF classification as a complement to ICD-10 could provide a better understanding of the consequences of diseases and how individual patients can cope with their health problems. ICF is feasible for secondary classifying of free text descriptions of disabilities stated in sick-leave certificates and seems to be useful as a complement to ICD-10 for sick-listing management and research.</p