Aims

To evaluate the effectiveness of an institutionally developed algorithm for evaluation and diagnosis of prosthetic joint injection and to determine the impact of this protocol on overall hospital re-admissions.p

Joint allotransplantation has a place in the treatment of joints destroyed by operation or disease. It is hoped that the results will improve with increasing knowledge of immunological mechanisms and with improvements in methods of internal fixation.

1. Two cases of locking of the metacarpo-phalangeal joint of the index finger are presented.

2. A simple classification of metacarpo-phalangeal joint locking is suggested, and the clinical features of the two main groups—degenerative and spontaneous—are described.

3. A routine approach to the treatment of the condition is suggested.

1. Twenty-two feet injured at the tarso-metatarsal level are reviewed.

2. Experiments with eleven cadaveric feet are reported.

3. The injuries are caused by forced plantar-flexion combined with rotation in most cases. Crushing of the foot alone often does not produce dislocation.

4. A classification is suggested.

5. The results of various treatments in this small series are presented. It is concluded that anatomical reduction is important, achieved if necessary by operation and internal fixation.

1. Five cases of locked metacarpo-phalangeal joint are described.

2. The anatomy of this joint is described and its bearing on the mechanism of locking discussed.

3. A method of treatment is suggested.

Two cases of neuropathic joints in diabetes mellitus are described. The condition, though rare, must be kept in mind in diabetes with neuropathy. With proper control of the diabetes and supportive measures to the joints the prognosis is relatively good.

1. By reducing the viscosity of the synovial fluid within the ankle joints of rabbits and then subjecting these to prolonged exercise, wear and tear of articular cartilage can be consistently produced.

2. This finding is an indirect confirmation of the view that fluid film lubrication is an important factor in the mechanical efficiency of joints.

3. The special properties of synovial fluid and articular cartilage that allow fluid film lubrication to exist within joints that are, in effect, slowly moving, heavily loaded, reciprocating bearings are discussed. They account for the remarkable resistance to wear and tear exhibited by synovial joints under physiological conditions.

1. The dynamics of synovial joints depends upon the geometry of the articular surfaces, which are always curved.

2. There are two types of articular curvature: ovoid (synclastic) and sellar (anticlastic).

3. The sellar type is mechanically more suited to movements in which sliding is combined with medial or lateral rotation (monodal conjunct rotation).

4. The movement of any hinge-joint is accompanied by a monodal conjunct rotation. This carries the moving part along a path that approximates (at least) to a path of minimal wear. The same is true of the paths of habitual effort-movement (ergodes) of other kinds of joint.

5. Evidence for the foregoing statements is drawn from both normal and abnormal joints, and a clinical application is suggested.

1. Two successive movements at a joint, if not in one and the same plane, constitute a diadochal movement.

2. Diadochal movements impose conjunct rotation upon the bone which has been moved. This may be countered by a rotation of opposite sense.

3. All muscles of a given joint are, therefore, rotators in some degree.

4. Upon the basis of these principles diagnostic and therapeutic suggestions are made.

1. All articulating cartilages are fibrocartilages.

2. The articular cartilages of the synovial joints are largely composed of collagen fibres.

3. These fibres form a dense network, the fibres of which run obliquely between the articular surface and the bone.

4. This network is operative when the parts are at rest and in contact under pressure. It takes the tensile component of the resultant shear stress, and is a postural mechanism of the joint.

5. The articular cartilage is most heavily chondrified at its centre, between the juxta-synovial and juxta-osseous parts.

6. The technique for demonstrating the fibrous structure is described.

1. Muscles acting upon any joint can be divided into two principal groups: muscles of displacement or spurt muscles, and muscles of stabilisation or shunt muscles.

2. Muscles which arise far from the joint are spurt muscles; those which arise near it are shunt muscles.

3. The fibrous tendon sheaths are joint-stabiising mechanisms.

4. The lumbrical and interosseous muscles are muscles of stabilisation of the digits.

5. The arrangement of the musculature is such as to ensure a constant pressure across the joint cavity during rest or uniform movement. The necessary centripetal force during movement is supplied mainly by the shunt muscles.

6. Experiments are described to illustrate these observations.

Link arthroplasty is a system of joint replacement in which the joint is left almost intact with no great removal of bone. It is based on a two-piece self-locking hinge slotted into the metacarpal head and phalangeal shaft. The operation is simple and no special instruments are needed. The preliminary follow-up of fifty-four metacarpo-phalangeal joint replacements showed thirty-five good and sixteen fair results.

1. By the use of a device that allows movement of a human finger joint to take place uninfluenced by muscle activity, the coefficient of friction has been determined between living articular surfaces.

2. The force of friction rises as the range of movement is increased, because of the tension then developing in the ligaments and the soft tissues surrounding the joint.

3. Measurements have also been made of the forces of friction within the ankle joint of the dog and within four types of reciprocating bearings (plastic, oil-lubricated, "floating" and hydrostatic).

4. By altering the load borne by the joints and bearings it has been shown that joints resemble in their behaviour those bearings in which a film of fluid is maintained between the fixed and moving surfaces, rather than bearings depending wholly or in part on boundary lubrication.

5. It is suggested that joints normally owe their great freedom of movement to a special type of fluid film lubrication that has been termed "weeping lubrication," supplemented by "floating lubrication," though on occasions boundary conditions may prevail.

Streptomycin and iso-nicotinic acid hydrazide are two powerful drugs lethal to tubercle bacilli, when access to the infected tissues is free. For early disease, before ischaemia and necrosis become established, they are curative: afterwards they are not. In this paper the use of surgery to augment their action has been discussed. The development of such methods may well revolutionise the treatment of skeletal tuberculosis. Therein lies a danger because attempts to cure the patient by exterminating the tubercle bacilli in his lesion may lead to a precarious recovery: treatment directed against the bacilli may greatly facilitate a real cure if constitutional treatment is also applied to make the patient immune. Revolutionary though the change may become, it will not be so great as the revolution which occurred thirty years ago when open-air hospitals were first provided for patients with skeletal tuberculosis. The first patient ever seen on a surgical ward by the author, when he was a student, suffices still as an example. A child with tuberculosis of the cervical spine was admitted from out-patients with multiple discharging sinuses from the neck which was supported in a sodden plaster jacket. "Whoever," said the house surgeon dramatically, "removes that plaster, will kill that child." Most unfortunately his words were true. Many other such patients could, in those days, be seen in the wards of city hospitals. It was largely due to the work of Sir Robert Jones, friend of children, that the value of constitutional treatment became recognised. With the combination of the old knowledge and the development of the new, a new chapter in the treatment of skeletal tuberculosis has opened and rapid restoration of function and permanent cure can now take the place of long and sometimes crippling illness.

We have used an experimental model employing the bent tail of rats to investigate the effects of mechanical forces on bones and joints. Mechanical strain could be applied to the bones and joints of the tail without direct surgical exposure or the application of pins and wires.

The intervertebral disc showed stretched annular lamellae on the convex side, while the annulus fibrosus on the concave side was pinched between the inner corners of the vertebral epiphysis. In young rats with an active growth plate, a transverse fissure appeared at the level of the hypertrophic cell layer or the primary metaphyseal trabecular zone. Metaphyseal and epiphyseal trabeculae on the compressed side were thicker and more dense than those of the distracted part of the vertebra.

In growing animals, morphometric analysis of hemiepiphyseal and hemimetaphyseal areas, and the corresponding trabecular bone density, showed significant differences between the compressed and distracted sides. No differences were observed in adult rats. We found no significant differences in osteoclast number between compressed and distracted sides in either age group. Our results provide quantitative evidence of the working of ‘Wolff’s law’.

The differences in trabecular density are examples of remodelling by osteoclasts and osteoblasts; our finding of no significant difference in osteoclast numbers between the hemiepiphyses in the experimental and control groups suggests that the response of living bone to altered strain is mediated by osteoblasts.