A finger function simulator and the laboratory testing of joint replacements

The design of a metacarpophalangeal (MCP) joint function simulator was undertaken and resulted in a versatile machine which offers the facility to apply both dynamic and static loading to a joint, following closely the physiological levels and patterns imposed in vivo. An additional feature was the opportunity to investigate the effect of varying the degree of joint instability. Long-term tests performed on Swanson silastic implants have produced failures of the kind seen clinically, which is very encouraging since it would seem to validate the claim that the simulator successfully imitates the finger function.

A laboratory and clinical study of pneumatic 'grip strength' devices

The use of inflated bags or cuffs to measure grip strength is now a well established technique. The method does have a number of problems. Bags of different diameter and volume were seen to give statistically significantly different pressure readings when squeezed by the same subjects. Different initial pressures (from 20 mmHg to 60 mmHg) also gave significantly different results both in laboratory tests on a materials testing machine and when patients with rheumatoid arthritis squeezed the bag. The technique of squeezing also affected the results. Despite the intrinsic drawbacks of the system, it is likely to remain in general use because of familiarity and convenience. We recommend the minimum details required when pneumodynamometer-derived data are published.

Prevalence of NSAID-induced gastrointestinal morbidity and mortality

Nonsteroidal antiinflammatory drugs (NSAID) are prescribed to tens of millions of patients worldwide, usually for the treatment of rheumatic symptoms. Rheumatologists consider them to be safe and effective drugs, whereas gastroenterologists have increasing concern regarding their gut toxicity. Although dyspepsia may be overcome by a variety of methods, major gut hemorrhage and perforation often occur in the absence of symptoms. It has been estimated that as many as one third of such events in people over age 60 years may be attributable to NSAID. We need, therefore, to devise strategies to cope with this problem. The goals of such strategies must include minimizing inappropriate NSAID prescribing and identifying particularly vulnerable patients among those who need such drugs so that prophylactic coprescription can be effectively and economically targeted.

A comparison of nefopam and flurbiprofen in the treatment of osteoarthrosis

A double-blind cross-over study was undertaken comparing the analgesic nefopam with the NSAID flurbiprofen in the treatment of osteoarthritis of the knees. Thirty patients entered the study and 18 completed the full trial protocol of one month on each drug. There was no significant difference in efficacy between the two treatments, although there were more side effects during the nefopam period. These must be balanced against the known gastrotoxicity of NSAIDs when choosing symptomatic treatment for osteoarthrosis.

Disappearing hypertrophic osteoarthropathy

A case is presented in which florid hypertrophic osteoarthropathy regressed clinically and radiologically when a Celestin tube was removed.

Identification of factors limiting the accurate measurement of plasma D-penicillamine in rheumatoid arthritis patients

Free and total reduced concentrations of D-penicillamine have been measured in the plasma of rheumatoid arthritis patients by HPLC and electro-chemical detection. A reverse-phase ion-pair separation in conjunction with a dual porous graphite electrode satisfied the requirements of robustness, sensitivity, selectivity and suitable retention time. Plasma levels measured between 1.5 and 3 h after an oral dose, were less than 0.3 to 57.6 mumol/L and 0.6 to 85.0 mumol/L (n = 26) for free and total reduced drug concentrations, respectively. Sources of error in the accurate measurement of peak plasma D-penicillamine levels were identified as oxidative loss and alteration in the free to protein-bound ratio in the period following sample collection.

Assessment of stiffness in rheumatology: the use of rating scales

A study of 100 patients with rheumatoid arthritis has shown good correlation amongst three rating scales when used for measuring severity of morning stiffness and severity of stiffness present at the time of interview. Duration of morning stiffness was found to correlate only moderately well with severity of morning stiffness and poorly with severity of stiffness present at the time of interview. Investigation of the patients' definitions of stiffness, with and without the aid of a list of descriptive words, indicated an inter-relationship of pain and limited movement in the majority. This linking of the two symptoms under the term 'stiffness' may explain why some objective methods of measurement do not appear to reflect the subjective stiffness of which patients complain.

Saline washout for knee osteoarthritis: results of a controlled study

Twenty patients with persistent symptoms due to osteoarthritis of the knee were randomly allocated to a saline washout or control group. Both groups showed improvement. Knee washout conferred no more benefit than intra-articular saline injection.

The effects of differing pharmaceutical preparations of indomethacin on night pain and morning stiffness in patients with rheumatoid arthritis

A study was carried out in 18 patients with rheumatoid arthritis to compare the effects of two different preparations of indomethacin with placebo on night pain, sleep and duration of morning stiffness. Patients were treated for 1 night each, in random order, with identical capsules containing 75 mg indomethacin, either as 'Indomod' (all sustained-release form) or 'Indocid' R (25 mg normal, 50 mg sustained-release form), or placebo as a substitute for their usual night-time medication. The results of visual analogue scale scores and a standard sleep assessment questionnaire score indicated the same order of effectiveness for each of the three parameters, with 'Indomod' best, 'Indocid' R intermediate and placebo worst, but only the difference in sleep was statistically significant. 'Indomod', therefore, might offer a slight advantage over the same dose of indomethacin as 'Indocid' R given at night. Less side-effects were produced by active treatment than by placebo and none was severe.

Measurement of stiffness in the metacarpophalangeal joint: the effects of physiotherapy

Five common modes of physiotherapy were applied to a group of normal subjects and to a group of patients with rheumatoid arthritis. The metacarpophalangeal joint stiffness was measured before therapy and immediately afterwards and the results compared. The only statistically significant result was that short-wave diathermy and ultrasound both reduced the amount of energy dissipated in the joints of the patients. No significant changes occurred in the normal group.

A microcomputer controlled hand assessment system used for clinical measurement

To improve the objectivity of clinical assessment of hand function, a microcomputer controlled system of force transducers has been developed and used to study twenty normal subjects and thirty-eight patients suffering from rheumatoid arthritis. The parameters measured were grip and individual finger forces, pan and kettle handle grip and lift force, key twist torque, lateral pinch force, and individual finger pulp pinch forces.

‘Power’ grip forces were found to be remarkably similar in the left and right hands as indeed was the contribution made by each finger to the total force. Pan grip and lift forces were also similar in left and right hands, but the grip force was far greater than the lift force in both normals and patients. Kettle grip forces were much less than the lift force in normal subjects, while patients gripped the kettle with almost as much force as they used to lift it.

Patients were weaker than normals exerting roughly one third of the forces of normals in all modes of measurement. There were different styles of lifting demonstrated by the patient group.

Measurement of stiffness in the metacarpophalangeal joint: circadian variation

A finger arthrograph has been used to investigate circadian variation of stiffness in the metacarpophalangeal joints of normal subjects. A marked increase in the resistive torques of male and female joints was noted during the early hours of the morning (typically 2 to 3 times the torque found during the afternoon). The amount of energy dissipated by the joint and associated soft tissues also showed a circadian variation, with the highest levels of energy dissipation again occurring during the early hours of the morning (0200-0400).