Porous tricalcium phosphate and transforming growth factor used for anterior spine surgery

Harvesting autologous bone graft from the iliac crest is associated with considerable secondary morbidity. Bone graft substitutes such as porous ceramics are increasingly used for spinal surgery. This paper presents the results of an animal study in which beta-tricalcium phosphate (beta-TCP) bone substitutes were used for anterior spinal surgery in sheep and baboons. The presented baboon study also investigated the effect of impregnating the ceramic material with transforming growth factor (TGF). In the first study, using the sheep model, a stand-alone instrumented anterior fusion was performed. The animals were randomized into three treatment groups: autologous bone, beta-TCP granules, and sham group. The results were analyzed biomechanically and histologically at three survival intervals: 8, 16 and 32 weeks. An additional animal group was added later, with ceramic pre-filled implants. In the second study, a baboon model was used to assess the osteointegration of a 15-mm-diameter porous beta-TCP block into the vertebral body. The experiment was partially motivated by a new surgical procedure proposed for local bone graft harvest. Three treatment groups were used: beta-TCP plug, beta-TCP plug impregnated with TGF-beta3, and a sham group with empty defect. The evaluation for all animals included computer tomograms at 3 and 6 months, as well as histology at 6 months. In the sheep model, the mechanical evaluation failed to demonstrate differences between treatment groups. This was because massive anterior bone bridges formed in almost all the animals, masking the effects of individual treatments. Histologically, beta-TCP was shown to be a good osteoconductor. While multiple signs of implant micromotion were documented, pre-filling the cages markedly improved the histological fusion outcomes. In the baboon study, the beta-TCP plugs were completely osteointegrated at 6 months. For the group that used ceramic plugs impregnated with TGF-beta3, no incremental advantage was seen as a result of this particular application. However, TGF-beta3 is a potent growth factor at a very low dose. Not only does it speed up the ceramic material resorption, but it is also responsible for massive regional new bone formation. More experiments are required to better understand the biological effects of this growth factor in relation to bone formation, and to be able to take clinical advantage of them.

[Physiotherapy in lumbar disc herniation ]

Physiotherapy is the treatment of choice in patients with symptoms caused by a lumbar disc herniation. In clinical practice a broad range of physiotherapeutic modalities has been revealed to be helpful. During the acute stage the efficacy of the McKenzie-concept, mobilisation therapies and traction has been demonstrated in randomized controlled trials with a blind assessor. In addition, pain reducing physical therapies such as cold or electrotherapy and non-steroidal anti-inflammatory drugs, analgesics and/or muscle relaxants are sensible initial accompanying treatments. The effectiveness of active physiotherapies such as training of local strength endurance of back and abdominal muscles has been proven in patients during the chronic stage. The indications for a in-patient rehabilitation programme, for surgery and the danger of developing chronic low back pain are discussed.

Prediction of depression in systemic lupus erythematosus patients using SF-36 Mental Health scores

OBJECTIVE

As depression is common in systemic lupus erythematosus (SLE) patients, we investigated whether and how the Medical Outcome Survey Short Form 36 (SF-36) scores, routinely used in the assessment of SLE patients, would indicate the absence or presence of depression.

METHODS

The Depression subscale of the Hospital Anxiety and Depression Scale (HADS-D) and the SF-36 were applied in a cross-sectional cohort of 60 SLE patients [mean age 45 (S.D. 15) yr, disease duration 11 (9) yr, 90% female, 100% Caucasians]. The SF-36 domain score with the closest association with HADS-D was used for further analysis. On the basis of HADS-D scores, the patients were split into two groups: one without depression (score<8) and the other with possible depression (score > or =8).

RESULTS

The SF-36 Mental Health score was most closely correlated to the depression score (rho=-0.69, P<0.0005). The calculated Mental Health score cut-off value which significantly differentiated possibly depressed from non-depressed SLE patients was 61. Its sensitivity for the detection of possible depression was 89%, its specificity 77% and its negative predictive value 97%.

CONCLUSIONS

The present study contributes to knowledge of means of excluding depression and the prevention of underdiagnosis and undertreatment of depression in SLE patients.

Do present damage and health perception in patients with systemic lupus erythematosus predict extent of future damage?: a prospective study

OBJECTIVE

To study whether either initial damage, disease activity, disease duration, age, a drug score, or health status would predict an increase in damage in patients with systemic lupus erythematosus (SLE) within the next three years.

METHODS

A three year prospective longitudinal study of a cohort of 141 consecutive patients with SLE attending a specialist lupus outpatient clinic from their first assessment between July 1994 and February 1995. Disease activity was assessed using the BILAG system, health status by the Medical Outcome Survey Short Form 20 with an extra question about fatigue (SF-20+), and damage by the SLICC/ACR Damage Index (SDI). Damage was reassessed three years later. Statistical analysis was carried out using logistic regression analysis (logXact).

RESULTS

133 female and 8 male patients with SLE (97 white subjects, 16 Afro-Caribbeans, 22 Asians, and 6 others) were included. Their mean (SD) age at inclusion was 41.1 (12.5) years and their disease duration 10.2 (6. 3) years. The mean measures at inclusion were: total BILAG 5.2 (range 0-17), total SDI 1.2 (0-7), drug score 1.2 (0-3); SF-20+: physical 58 (0-100), role 54 (0-100), social functioning 71 (0-100), mental health 64 (16-100), health perception 44 (0-100), pain 53 (0-100), fatigue 59 (0-100). Four patients were lost to follow up because they had moved. At three years in 33 patients the total SDI had increased to a mean of 1.5 (0-7) (n=130). Moreover, seven patients had the maximum damage as they had died during the follow up period. The only variables with an independent and significant contribution in predicting damage at three years were the total damage score (odds ratio (OR)=1.46; 95% CI 1.04 to 2.05), and health perception (OR=0.96; 95% CI 0.93 to 0.99) at inclusion.

CONCLUSIONS

Of all the variables at inclusion only the total damage score and SF-20+: health perception, significantly predicted an increase in damage, for patients with SLE, three years later.

PRISM (Pictorial Representation of Illness and Self Measure)- a novel visual method to assess the global burden of illness in patients with systemic lupus erythematosus

OBJECTIVE

For patients with chronic illnesses the global burden of illness is a crucial health measure hitherto neglected in research studies and clinical practice. We tested the application and validity of PRISM (Pictorial Representation of Illness and Self-Measure), a novel visual method for assessing the burden of illness, in patients with systemic lupus erythematosus (SLE).

METHOD

PRISM was applied in a cross sectional sample of 60 patients with SLE. Correlations were assessed between a quantitative measure derived from PRISM (Self-Illness Separation-SIS) and sociodemographic factors, measures of disease activity, damage, physical and psychological disability variables, as well as coping resources.

RESULTS

The PRISM task was understood by all but one patient, and was in every instance completed in less than 3 minutes. SIS correlated with SF-36 physical health, coping resources as assessed by Sense of Coherence (SOC), and age, but not with disease activity or damage. In multiple regression analyses, independent contributions to SIS were observed for SF-36 physical component scale (contributing 12% of the variance). SOC (10%) and age (14%).

CONCLUSION

PRISM is a new non-verbal measure to assess burden of illness. As in previous studies, PRISM was well accepted and understood by patients with SLE, quick to complete, and yielded meaningful information consistent with that in earlier research work.

Maximal isometric muscle strength: normative values and gender-specific relation to age

To date, there have been very few studies on the age dependence of maximal isometric muscle strength (MIMS) in healthy subjects aged 20-80 years, based upon measurements of a large number of functional muscle groups (FMGs). Using a hand-held pull gauge it is possible to measure MIMS of nearly every FMG. The objectives of this study were to obtain normative values for MIMS, to evaluate differences in MIMS in relation to gender and body side and to compare the age dependence of muscle strength between women and men. In a convenience sample of 290 healthy women (aged 20-82 years) and 253 men (aged 21-79 years), MIMS of 51 FMGs was measured. For each FMG the age dependence of MIMS was depicted, side and gender specific, as percentile curves and was analysed using linear quantile regression analysis. MIMS was found to be significantly higher in men than in women and higher on the right than on the left side. A biphasic model with linear equations for strength medians was derived for each gender. The age at transition from phase 1 to phase 2 was 55 years (SD 8) for women and 49 years (SD 13) for men. During phase 1, MIMS did not decrease significantly. During phase 2, MIMS decreased in all FMGs in both genders with a steeper slope in women (-0.92) than in men (-0.63). The age dependence of MIMS differed significantly between women and men. The present study gives gender-specific equations which enable one to calculate normative values for MIMS, as measured with a pull gauge, based upon age. These normative values will allow an objective assessment of patients with diminished muscle strength as, for example, in myositis, rheumatoid arthritis and nerve root compression syndromes or in the elderly.

The influence of mechanical stimulus on the pattern of tissue differentiation in a long bone fracture--an FEM study

2D, coronal plane, finite elements models (FEMs) were developed from orthogonal radiographs of a diaphyseal tibial fracture and its reparative tissue at four different time points during healing. Each callus was separated into regions of common tissue histology by computerised radiographic analysis. Starting point values of tissue material properties from the literature were refined by the model to simulate exactly the mechanical behaviour of the subject's callus and bone during loading. This was achieved by matching measured inter-fragmentary displacements with calculated inter-fragmentary forces. Stress and strain distributions in the callus and bone were calculated from peak inter-fragmentary displacements measured during natural walking activity, and were correlated with the subsequently observed pattern of tissue differentiation and maturation of the callus. The growth and stiffening of the external callus progressively reduced the inter-fragmentary gap strain. Partial maturation of the gap tissue was apparent only one week before fixator removal. Principal stresses in the callus were compared with 'yield stresses' in corresponding tissue from the literature. This indicated the presence of stress concentrations medial and lateral to the fracture gap, which probably caused tissue damage during normal activity levels. Tissue damage may also have precipitated partial structural failure of the callus, both of which were believed to have delayed healing during the middle third of the fixation period. Had the fixation device provided greater inter-fragmentary support during early healing, this may have prevented callus failure and the consequent delay in healing. A further benefit of this would have been the reduction of the initially high intra-gap tissue strains to a magnitude more conducive to earlier maturation of the bridging tissue that united the bone.

Sense of coherence--a protective factor for depression in rheumatoid arthritis

OBJECTIVE

A stress-vulnerability model of depression was investigated in patients with rheumatoid arthritis (RA). Antonovsky's Sense of Coherence (SOC) was examined as a factor protecting against depression.

METHOD

Relationships between sociodemographic factors, disease activity, functional impairment, pain, depression, and SOC were assessed using multivariate methods in a cross sectional sample of 89 consecutive outpatients with RA.

RESULTS

Increased prevalence of depression was associated with low SOC and high self-rated pain levels, but not with other factors assessed. By multiple regression analysis, independent contributions to depression were observed for SOC (23% of variance) and for pain (24% of variance), but not functional impairment or disease activity.

CONCLUSION

Comprehensive models of adjustment in RA need to include protective factors such as SOC, in addition to pain and other pathological variables. SOC may be helpful in identifying individuals with RA who are particularly vulnerable to depression, who may be helped by focused psychological interventions such as cognitive therapy.

[Immobilizing muscle weakness accentuated in leg and proximal muscles]

A 54 year old waiter was referred to the hospital because of proximal muscle weakness, most pronounced in his legs, which progressed to an inability to stand or walk within weeks. Myopathy was diagnosed based on the muscle biopsy findings and myositis was ruled out by laboratory and biopsy results. Further investigations led us to exclude an endocrine cause, hypovitaminosis D, infectious myopathy or a paraneoplastic syndrome. Heteroanamnesis revealed severe alcoholism, lasting for more than 30 years. The presumed alcohol induced hepatopathy was confirmed by liver biopsy. There were no signs of an acute alcoholic myopathy, as the weakness had developed rather insidiously, there was no elevation of the CK serum level nor myoglobinuria and a type 2 fibre atrophy was found by muscle biopsy. As expected the weakness improved under abstention. Thus the final diagnosis of a chronic alcohol induced myopathy was established.

Functional disability and end organ damage in patients with systemic lupus erythematosus (SLE), SLE and Sjögren's syndrome (SS), and primary SS

OBJECTIVE

To determine the accumulated end organ damage and health status in patients with SS and to compare with patients with SLE (with or without SS).

METHODS

Thirty-seven patients with primary SS were studied and compared with 120 patients with SLE and 21 patients with SLE and SS. The Medical Outcome Survey Short Form 20 with an additional question for fatigue was used to assess health status. The SLICC/ACR damage index with a supplementary oral section was used to assess end organ damage. For statistical analysis, logistic regression analysis, Fisher's exact test, and Kruskal-Wallis rank tests were applied.

RESULTS

Patients in all 3 groups had reduced quality of life with respect to all aspects of functional status and well being. There was no difference between the groups. In the primary SS group, the greatest damage was in the oral section (62% of patients). The patients with SLE and SS had the greatest renal, peripheral vascular, and musculoskeletal damage (24, 19, 38% of patients, respectively) followed by the SLE group. Ocular damage was more common in the primary SS group, but that was due to older age in this group. Malignancy was most common in the primary SS group (11%). Other organ damage scores did not differ between groups.

CONCLUSION

End organ damage is uncommon in primary SS (with the exception of oral damage), but the degree of functional ability is as great as in SLE.

Consistency and validity of patient administered assessment of quality of life by the MOS SF-36; its association with disease activity and damage in patients with systemic lupus erythematosus

OBJECTIVE

To investigate the metric properties and validity of the assessment of quality of life by the MOS Short Form 36 (SF-36) in patients with systemic lupus erythematosus (SLE) and to examine the effect of disease on quality of life.

METHODS

Cross sectional study of 150 patients with SLE (age: mean 39.7 yrs, SD 11.4 yrs; 95% female) attending 2 specialist lupus clinics between November 1994 and April 1995. Shortly before or after the consultation patients completed the SF-36 and the MOS SF-20 with an additional question about fatigue (SF-20+) in random order. Disease activity was measured by the British Isles Lupus Activity Group System (BILAG), disease damage by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index (SLICC).

RESULTS

SF-36 domains were shown to be internally consistent (Cronbach's coefficient alpha > or = 0.71). Significant associations of the SF-36 domains with the corresponding domains of the SF-20+ and with global disease activity measured by BILAG were observed. SF-36 scores in patients with SLE were significantly lower than in controls. Different disease activity levels were significantly associated with different quality of life scores, with excellent ability to record the continuum from good health to serious illness by the SF-36. Disease activity had greater effect on quality of life than age, cumulative damage, or disease duration.

CONCLUSION

This study shows the SF-36 is internally consistent and proves construct, discriminatory, and criterion validity for the SF-36 and construct validity for the SF-20+ in patients with SLE. The SF-36 is preferred because of its broader scope of questions, its widespread use, and previous international validation for a wide variety of diseases.

Association of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index with measures of disease activity and health status in patients with systemic lupus erythematosus

OBJECTIVE

To examine the internal consistency and validity of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) with respect to disease activity, health status, and medication score.

METHODS

A prospective cross sectional study of patients with systemic lupus erythematosus (SLE) attending a specialist lupus outpatient clinic between July 1994 and February 1995. The internal consistency of the SDI components was examined using Cronbach's coefficient alpha. The associations of the SDI components with disease activity measured by the British Isles Lupus Assessment Group (BILAG) index, health status measured by the Medical Outcomes Study (MOS) Short Form 20, and with a medication score were analyzed using Spearman's rank correlation coefficient (p).

RESULTS

133 women and 8 men ranging in age from 20.1 to 88.7 years (mean 41.1, SD 12.5) were studied. With few exceptions, the components of the SDI that reflect damage in different organ systems were not associated with each other. We found a significant although weak relationship between some related SDI and BILAG components (p 0.25 to 0.28; p < 0.01). While damage to the musculoskeletal system was associated with limitations in physical functioning measured with the MOS Short Form 20 (p-0.30; p < 0.01) and renal damage inversely with fatigue (p-0.23; p < 0.01) there was no significant relationship of other SDI components with the MOS Short Form 20. Renal and neuropsychiatric damage were associated significantly with the medication score (p 0.27 and 0.23; p < 0.01).

CONCLUSION

The components of the SDI are valid in that they are associated with disease activity in the respective organ systems and some of them with a medication score. However, damage in different organ systems in SLE does not follow a common pattern. It is thus suggested that the SDI profile be used in addition to the SDI total score as an endpoint in clinical and epidemiological studies.

Further validation of the BILAG disease activity index in patients with systemic lupus erythematosus

OBJECTIVE

To examine the association among the BILAG disease activity index components and their relations with global assessments, health status, and laboratory tests with regard to the validity of the BILAG index.

METHODS

A cross sectional study of consecutive patients with systemic lupus erythematosus (SLE) attending a specialist lupus outpatient clinic between July 1994 and February 1995. The internal consistency of the British Isles Lupus Assessment Group (BILAG) index-a disease activity assessment system for SLE patients, based on the principle of the physician's intention to treat-was examined using Cronbach's coefficient alpha. The association of the components of the BILAG index with health status as measured with the MOS Short Form 20 (SF-20), with patients' and doctors' global assessments of patient wellbeing and with laboratory tests was analysed with Spearman rank correlations.

RESULTS

133 female and eight male patients, age 20.1 to 88.7 years (mean 41.1, SD 12.5), were included. With few exceptions, the components of the BILAG index which reflect disease activity in different organ systems were not associated with each other. With the exception of the mucocutaneous component, we found a significant relation between all components of BILAG and global assessment of patient wellbeing, health status, erythrocyte sedimentation rate, or serum C3 level.

CONCLUSIONS

The study confirms the validity of all but the mucocutaneous component of the BILAG index. However, disease activity in different organ systems in SLE does not follow a common pattern. Thus the individual BILAG components should be used rather than the total BILAG score as a primary endpoint in clinical and epidemiological studies. To capture the total effect of SLE on an individual measures of disease activity, damage, and health status are all needed.

Infection of a total knee joint prosthesis by peptostreptococcus micros and propionibacterium acnes in an elderly RA patient: implant salvage with longterm antibiotics and needle aspiration/irrigation

We describe the favourable long-term outcome after late total knee joint prosthesis infection in an elderly RA patient. Peptostreptococcus micros and Propionibacterium acnes were cultured from the synovial fluid, and the finding of a coexistent abscess at the root of a wisdom tooth suggested a dental origin to the joint infection. Long-term antibiotics in conjunction with aspiration/irrigation resulted in salvage of the implant and an excellent functional outcome.

Low serum creatine kinase activity is associated with muscle weakness in patients with rheumatoid arthritis

OBJECTIVE

In rheumatoid arthritis (RA) serum creatine kinase (CK) is reduced in association with inflammatory response variables. Our objective was to examine whether low CK is associated with muscle weakness and to what extent the hypothesized relationship between CK and muscle weakness can be explained by anthropometric and sociodemographic variables and/or disease variables.

METHODS

Cross sectional and longitudinal retrospective analyses of clinical, radiological, and biochemical data of a prospective cohort of consecutive patients with RA. Isometric muscle strength was measured with a validated muscle strength index (MSI); CK was measured with an enzymatic assay (N-acetyl-cysteine, 37 degrees C).

RESULTS

65 patients were enrolled in the study and we obtained complete one year followup data from 47. In cross sectional analysis, CK was a significant, moderate correlate of the MSI (r = 0.43, p < 0.01). CK remained a significant explanatory variable of the MSI in multivariate models that controlled for demographic variables and lean body mass, corticosteroid use, and biochemical, clinical, and radiological disease variables. In longitudinal dichotomous analyses, worsening in CK was weakly but significantly associated with decreased muscle strength, whereas in linear analyses the association did not reach significance.

CONCLUSION

In patients with RA, low CK activity is associated with muscle weakness. Demographic, anthropometric, and disease variables related to muscle mass or muscle atrophy explain only part of this association. Our findings support the hypothesis that muscle weakness may be partly caused by a disease related reduction of CK activity independent of muscle atrophy.

SLICC/ACR Damage Index is valid, and renal and pulmonary organ scores are predictors of severe outcome in patients with systemic lupus erythematosus

We investigated the Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) Damage Index as a predictor of severe outcome and an indicator of morbidity in different ethnic groups, and in regard to its validity. We retrospectively studied disease course within 10 yr of diagnosis in an inception cohort of 80 patients with systemic lupus erythematosus (SLE). The mean renal damage score (DS) at 1 yr after diagnosis was a significant predictor of endstage renal failure and the mean pulmonary DS at 1 yr significantly predicted death within 10 yr of diagnosis. Compared to Caucasians, Afro-Caribbeans and Asians had significantly higher mean total DS at 5 and 10 yr, and higher mean renal DS at 10 yr. At 5 yr, the mean renal DS in Afro-Caribbeans and the mean neuropsychiatric DS in Asians were significantly higher than in Caucasians. The rate of endstage renal failure in Caucasians was significantly lower than in the other ethnic groups. Our results confirm the validity of the SLICC/ACR Damage Index.

Not all stoops are due to osteoporosis

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Construct validation of the ACR 1991 revised criteria for global functional status in rheumatoid arthritis

In order to assess the construct and discriminatory validity of the 1991 ACR functional status criteria for rheumatoid arthritis (RA), a cross-sectional analysis of 62 consecutive patients with RA (according to the American Rheumatism Association 1987 revised criteria) who were attending the outpatient clinic of rheumatology, University Hospital Zürich, was carried out. A moderate-to-strong association of the ACR criteria with pain (r = 0.54), the tender (r = 0.54) and swollen joint count (r = 0.31), grip strength (r = -0.49), C-reactive protein (r = 0.35), the HAQ disability index (r = 0.76), self-perceived global health (r = 0.58), and the Larsen radiological score (r = 0.32) was found. The mean scores of most disease parameters and all 8 domains of the health assessment questionnaire were significantly different between, and increased regularly across, the 4 classes. We conclude that the ACR 1991 functional status criteria for RA are a valid measure of the consequences of impairment and discriminate well the physical functional status.

Muscle strength assessment in polymyositis and dermatomyositis evaluation of the reliability and clinical use of a new, quantitative, easily applicable method

OBJECTIVE

To evaluate the feasibility and the reliability of a quantitative method of maximal isometric strength measurement for the assessment of patients with myositis in clinical practice and research.

METHODS

Three observers independently examined the strength of 13 muscle groups of 7 patients with stable polymyositis and dermatomyositis (PM/DM) using a handheld pull-gauge. Reliability was assessed following a balanced random 3-way cross classification with interactions and using the analysis of variance method. Serial followup strength data for 2 patients were compared to change in creatinine kinase (CK) levels.

RESULTS

All measurements could be performed without causing pain to the patients. One single test including 13 muscle groups was done in 7 min or less. Both intra and interobserver correlations were strong and significant for all muscle groups. The intraobserver reliability ranged from 0.88 for elbow extensors to 0.98 for knee extensors and cervical spine flexors. The interobserver reliability ranged from 0.81 for elbow flexors to 0.98 for knee extensors and cervical spine flexors. The followup of 2 cases yielded moderate to strong correlations of serial strength measurements with CK levels.

CONCLUSION

Serial measurement of isometric muscle strength with a handheld pull-gauge is a feasible, inexpensive, time efficient and reliable method and may provide additional quantitative information in the clinical assessment of patients with myositis.