1. The importance of accurate methods of measuring the strength of muscles and the amplitude of joint movements in man, both in clinical fields and as criteria of normal function, is discussed. 2. The advantages and disadvantages of subjective and objective methods are reviewed. 3. The main types of apparatus used for the assessment of muscle strength in both normal and clinical conditions are described. A dynamometer of the strain-gauge type is recommended. 4. Methods of measuring the amplitude of movements in man are also described. The protractor type arthrometer is thought to be the most suitable for routine clinical work, but for research purposes a radiographic method may be preferable. 5. The following factors, which must be considered if the measurements taken are to be of greatest use, are discussed: posture, test procedure, standards for comparison, nomenclature and normal variability

We investigated the long-term changes in the Harris Hip and Knee Society scores (HSS and KSS) to determine whether they result from overall functional decline rather than actual changes in the condition of the prosthesis. The HHS for 106 total hip arthroplasties with a minimum follow-up of ten years, no medical complications after operation and no evidence of radiological loosening, and the KSS for 264 total knee arthroplasties with a minimum follow-up of 12 years and no medical complications after operation or signs of radiographical loosening were evaluated. There were statistically significant drops in the functional scoring components of the joint evaluation systems despite no loosening of the prostheses or other significant medical complications. The HHS declined at an average of 0.67 points per year from between three and ten years after operation (p < 0.0001). Contributing to this were deterioration in gait and limp (p < 0.0004), the use of support aids (p < 0.0001), the distance walked (p < 0.0001) and the ability to climb stairs (p < 0.0455). The functional component of the KSS declined significantly at an average 0.88 points per year betwen the third and 12th years (p < 0.0001). There were significant declines in every component of the functional score including the distance walked (p < 0.0001), the ability to climb stairs (p < 0.0001) and the use of support aids (p < 0.0001). The knee score component of the KSS did not decline significantly (p < 0.9750). The combination of functional and pain scores within the HHS system leads to an inaccurate decline in the entire score. The decline of HHS and Knee Society functional scores in total joint arthroplasties, in the absence of implant-related problems, suggests that deterioration in the functional capacity of ageing patients is an important factor in longitudinal studies using these scoring systems

Amputation or post-mortem specimens from eight cases of joint tuberculosis, with immobilisation changes in bone, have been studied by fine-detail slab radiographs and subsequent histological examination. The findings in three of these cases are presented in detail. The immobilisation changes take the form of a true osteoporosis, which is strikingly focal in nature. In the adult the sites of most marked involvement include the subcortical bone adjacent to articular surfaces and the bone in the neighbourhood of the obliterated epiphysial plates. Areas of permanent change in bone structure may result, although commencing "repair" is seen in the form of newly developed bone trabeculae in the osteoporotic areas. In one case, where immobilisation occurred at an early age, changes in the growing epiphysial plates were produced in addition to osteoporosis. This is correlated with the known susceptibility of growing epiphysial cartilage to a wide variety of damaging agents. Radiologically, it is important to discriminate between these immobilisation changes and the bone destruction which might be produced by extension of the tuberculous lesion itself

1 . A small series of fractures of the calcaneum with distortion of the subtalar joint has been reviewed. 2. All were treated by subtalar fusion, in most as part of the primary treatment. 3. In all patients the subtalar joint fused by bone without post-operative plaster immobilisation. 4. Plaster immobilisation is not only unnecessary, it is undesirable. 5. Heavy work, including work on ladders and scaffolding, can be undertaken after subtalar fusion

An 18-year-old girl with moderate joint laxity presented with recurrent dislocation of the calcaneocuboid joint in both feet. We achieved successful stabilisation on both sides by reconstruction of the ligaments and capsule using the plantaris tendons

There have been many reports which suggest that in patients with tibiofemoral osteoarthritis, a reduction in joint space is demonstrated better on weight-bearing radiographs taken with the knee in semiflexion than in full extension. The reduction has been attributed to the loss of articular cartilage in the contact area in a semiflexed arthritic knee. None of these studies have, however, included normal knees. We have therefore undertaken a prospective, double-blind, randomised study in order to evaluate the difference in the joint-space of arthroscopically-proven normal tibiofemoral joints as seen on weight-bearing full-extension and 30° flexion posteroanterior radiographs. Twenty-two knees were evaluated and the results showed that there may be a difference of up to 2 mm in the two views. This difference could be attributed to the inherent differential thickness of the articular cartilage in different areas of the femoral and tibial condyles and a change in the areas of contact between them

This is the first time that the principle of the mould—the principle of guiding the repair of nature for the purpose of recreating a destroyed or damaged structure, has been applied to surgery. The evolution of the method to its present encouraging stage is the result of the co-operative, professional family spirit of the Massachusetts General Hospital. We all share in it. We share it with the general surgeon because of his contributions to surgical technique. We share it with the "medical man" because of his pre-operative and post-operative care of the patient; because of his guidance as to when, and when not, to operate; and because of the many friendly arguments which are productive of so much good. We share it with the anaesthetist because of his clinical judgment of the patient, his selection of anaesthetic agent, and his continuous, conscientious administration of the anaesthetic throughout the operation. I am going to change from "we" to "I." I owe so much to my assistants, from the first to the last: Bill Rogers, Eddie Cave, George Van Gorder, Paul Norton, Milton Thompson, Otto Aufranc, and Carroll Larson. I want to thank them all for helping to carry the load, for remembering the things that I forgot, and for making helpful suggestions which often led to improvement in surgical technique or to the construction of a useful instrument. I want to pay tribute to the staff of the Orthopaedic Service of the Massachusetts General Hospital and to thank its members for kindly scepticism, constructive criticism, and neverfailing loyal support. The subject of this lecture, "Evolution of Mould Arthroplasty of the Hip Joint," is appropriate for a Moynihan lecture. It is not the work of one man alone. It is the work of one man, supported by a co-operative, helpful, and friendly hospital staff. This is what Lord Moynihan strove so hard to bring about at a time when surgeons viewed one another as rivals. To quote Dr William Mayo: "It is to Lord Moynihan's everlasting credit that, largely as a result of his unceasing efforts, surgeons came to consider themselves as fellow-workers in a cause."

1. Destructive changes in a knee joint, eventually requiring arthrodesis, are reported in a patient who had undergone renal transplantation. 2. The underlying pathology was avascular necrosis with separation of large osteochondral fragments. 3. The pathogenesis is discussed

The patterns of laxity of normal wrists subjected to dorsal and volar stresses were analysed. Dorsal and volar displacement tests were carried out on both wrists of 50 subjects under image-intensifier control. Lateral projections in neutral, and dorsal and volar stress positions were taken to analyse the behaviour of the carpal bones. Varying degrees of capitolunate subluxation under dorsal and volar stress were noted. Dorsal displacement of the capitate appeared to be more prominent than volar displacement. The lunate either extended or subluxed dorsally in response to a dorsal stress, suggesting a different pattern of laxity for the radiolunate joint. These observations provide a baseline for the interpretation of dorsal and volar stress views in the symptomatic wrist

1. The results of excision of the trapezium for degenerative changes in the first carpometacarpal joint are given. 2. The grip is usually permanently reduced by an appreciable amount, but functional power is improved by the absence of pain. 3. The patients most commonly affected, middle-aged women, usually derive appreciable benefit. 4. Recovery after operation often takes several months. 5. Interference with the radial nerve should be preventable by modification of the incision

We investigated 57 patients with sickle cell anaemia (HbSS) and bone and joint changes. Osteonecrosis simulating a wide range of conditions was a common radiological feature, and osteomyelitis occurred in 61% of cases. Salmonella species were the commonest causative organisms, occurring in 71% of patients with osteomyelitis, although salmonella septic arthritis occurred in only two. The distinction between vaso-occlusive bone crisis and acute osteomyelitis was often difficult since the classical clinical and radiological features and laboratory findings also occurred in bone infarction, a common feature of the disease

The immigrant Asian population of Bradford has a relatively high incidence of bone and joint tuberculosis, which now accounts for most of this disease in the city. One hundred and seventy-six cases of skeletal tuberculosis are reviewed and indigenous and Asian disease compared. The disease in Asians is more acute with greater systemic disturbance. The abscess is often warm, larger and quicker to develop and there is more likely to be multiple site involvement. Tuberculosis is particularly seen in the knee and cervical spine in the Asian as compared with the hip and lumbar region in the indigenous population. The course of the disease is shorter and there are fewer recurrences in the Asian patient

We report a prospective study of gait and tibial component migration in 45 patients with osteoarthritis treated by total knee arthroplasty (TKA). Migration was measured over two years using roentgen stereophotogrammetry. We used the previously established threshold of 200 μm migration in the second postoperative year to distinguish two groups: a risk group of 15 patients and a stable group of 28 patients. We performed gait analysis before operation and at six months and at two years after TKA. On all three occasions we found significant differences between the two groups in the mean sagittal plane moments of the knee joint. The risk group walked with higher peak flexion moments than the stable group. The two groups were not discriminated by any clinical or radiological criteria or other gait characteristics. The relationship which we have found between gait with increased flexion moments and risk of tibial component loosening warrants further study as regards the aetiology of prosthetic loosening and possible methods of influencing its incidence

1. Sixty feet operated upon either by triple or pantalar tarsal fusion for instability after poliomyelitis were re-examined ten to twenty-four years later. 2. After triple fusion with preservation of the ankle joint there was a striking absence of late osteoarthritis of the ankle, and only a low incidence of troublesome lateral instability of the ankle. The results were generally good provided the patient had reasonable power of extension of the knee. 3. Triple arthrodesis for completely flail foot in patients without active muscle control of the knee was often disappointing, so far as the limb as a whole was concerned, because of a persistent flexion deformity of the knee which usually necessitated the wearing of an appliance. 4. The results of pantalar arthrodesis for the flail foot were satisfactory. When this operation was performed (with the foot in slight equinus) in patients who lacked active extension of the knee it helped to stabilise the knee in walking by encouraging hyperextension

We excised the anterior cruciate ligament from the left stifle of 24 sheep and replaced it by a polyester fibre implant routed 'over the top' of the femoral condyle and fixed, using grommets and screws. All the joints were sound, and the animals moved normally until they were killed at six, 12 and 24 months after operation. We found that the implants were always covered by host tissue, which matured into bundles with a histological appearance similar to the natural ligament. The implants were joined to the bones by organised fibrous tissue and there was no anchorage loosening. There was no synovitis, but the operated joints showed progressive cartilage degeneration. The reconstructed joints became less stable immediately after operation, but regained normal stability as the neoligaments developed. The neoligaments lost strength with time, despite tissue ingrowth. The good functional, biomechanical, and histological results justify clinical trials of this type of implant

We present the outcome of the treatment of chronic post-traumatic contractures of the proximal interphalangeal joint by gradual distraction correction using an external fixator. A total of 30 consecutive patients with a mean age of 34 years (17 to 54) had distraction for a mean of 16 days (10 to 22). The fixator was removed after a mean of 29 days (16 to 40). Assessment at a mean of 34 months (18 to 54) after completion of treatment showed that the mean active range of movement had significantly increased by 63° (30° to 90°; p < 0.001). The mean active extension gained was 47° (30° to 75°). Patients aged less than 40 years fared slightly better with a mean gain in active range of movement of 65° (30° to 90°) compared with those aged more than 40 years, who had a mean gain in active range of movement of 55° (30° to 70°) but the difference was not statistically significant (p = 0.148). The use of joint distraction to correct chronic flexion contracture of the proximal interphalangeal joint is a minimally-invasive and effective method of treatment

Cadaveric lumbar intervertebral joints were loaded to simulate the erect standing posture (lordosis), and the erect sitting posture (slightly flexed). The results show that, after the intervertebral disc has been reduced in height by a period of sustained loading, the apophysial joints resist about 16 per cent of the intervertebral compressive forces in the erect standing posture, whereas in the erect sitting posture they resist none. The implications of this in relationship to degenerative changes and to low backache are discussed

We report two cases of fungal infection of prosthetic joints which were successfully treated by the incorporation of fluconazole into polymethylmethacrylate beads inserted at the time of debridement

The role of inflammatory cells in aseptic loosening and failure of cemented joint replacements is unclear. Inflammatory cells from the revision joint capsule of four failed hip arthroplasties were examined to determine their nature and resorptive capacity. The capsules contained numerous macrophages and abundant foreign-body macrophage polykaryons, distinguished from osteoclasts by their antigenic phenotype and lack of response to calcitonin. When cultured on cortical bone slices in vitro, both macrophages and macrophage polykaryons produced small resorption pits and were associated with areas of superficial resorption of the bone surface. These results indicate that foreign-body induced macrophages and macrophage polykaryons are capable of a type of low-grade bone resorption which may be of pathogenic significance in the loosening of cemented joint prosthetic components