Objectives

The ability to determine human bone stiffness is of clinical relevance in many fields, including bone quality assessment and orthopaedic prosthesis design. Stiffness can be measured using compression testing, an experimental technique commonly used to test bone specimens in vitro. This systematic review aims to determine how best to perform compression testing of human bone.

1. Isolated dislocation of the radius at the elbow occurs most commonly as a pronation injury, associated with slight elbow flexion and a varus strain. Disruption of the radio-ulnar articulation occurs primarily because of tearing of the annular ligament, which is the most important reinforcing structure of this joint. The tensing of the interosseous membrane through neutral into supination, and consequently the approximation of the radius to ulna, supports the recognised supination manoeuvre to reduce such an injury. 2. It is suggested that this injury may be more common than previously appreciated. It may be not diagnosed, it may be over-diagnosed as total dislocation of the elbow, or it may be belatedly diagnosed as a congenital dislocation of the radial head

1. Thirteen cases of fracture of the lateral process of the talus seen over a period of thirteen months are reported. 2. The mechanism of the injury would appear to be inversion strain of the foot with dorsiflexion of the ankle. 3. The diagnosis would no doubt be made more often if the possibility of this fracture were kept in mind, and if radiographs of good quality were taken with the ankle at 0 degree and the leg rotated inwards 10 to 20 degrees. 4. With regard to treatment, early operation appears to give good results, a single large fragment being reduced accurately and small or comminuted fragments being removed

Any operation involving the implantation of a foreign body increases the risk of infection. The implant material and its surface, the dead space, and any necrosis or vascular changes play a significant role in susceptibility to infection. We investigated the effect of the dead space in an intramedullary nail on the rate of local infection. We inoculated the intramedullary cavities of rabbit tibiae with various concentrations of a human pathogen, of Staphylococcus aureus strain, and then inserted either a solid or a hollow slotted stainless-steel nail. We found a significantly higher rate of infection after use of the slotted nail (59%) than after the solid nail (27%) (p < 0.05)

Aims

The primary aim of the study was to compare the knee-specific functional outcome of robotic unicompartmental knee arthroplasty (rUKA) with manual total knee arthroplasty (mTKA) for the management of isolated medial compartment osteoarthritis. Secondary aims were to compare length of hospital stay, general health improvement, and satisfaction between rUKA and mTKA.

We used 15 pairs of femora from fresh human cadavers to study the effects of the size and location of the entry hole for an intramedullary nail on the strength of the femur. Right femora were used as controls. Left femora in group 1 had a 10 mm entry hole in the 'ideal' location in the piriformis fossa. Group 2 had a 14 mm entry hole in the same position and group 3 had a 14 mm entry hole anterior to this on the superior aspect of the femoral neck. Femora were equipped with strain gauges and loaded to failure in compression. There was reduced stiffness and load to failure in group 3 specimens, suggesting that the location of the hole was more important than its size

1. An experimental study of the healing mechanism in circumscribed defects in femora of albino rats of the Wistar strain is described. 2. Only the outer one-fifth of the defect is repaired by subperiosteal bony callus, the rest of the defect being repaired by endosteal callus. 3. Subperiosteal callus does not bridge the defect until endosteal callus is developed fully. 4. As peripheral callus matures the greater part of the endosteal callus is resorbed, with the exception of trabeculae attached to the margin of the defect. 5. The resorbed area in the medullary part of the defect is gradually obliterated by deposition of inner circumferential lamellae. 6. There appear to be differences between the mechanism responsible for repair of fractures of a long bone and that which heals circumscribed bone defects

We measured the stability of fixation in femoral neck fractures treated with von Bahr screws, investigated the influence of impaction and correlated peroperative stability with the clinical results. Stability was measured at operation using a metal probe fitted with strain gauges. Its tip was anchored in the subchondral bone of the femoral head and its lateral end was fixed in the lateral femoral cortex. The shearing force produced by longitudinal compression applied to the foot of the operated leg was recorded. The results in 41 consecutive patients all followed for 30 months, showed that fractures with early loosening or nonunion had all had significantly poorer stability than the fractures that had healed. Impaction improved stability in only 23 out of the 41 fractures; in the others stability had deteriorated or was unchanged

1. Pain in the elbow in javelin throwers is a common complaint. 2. The commonest type is caused by recurrent strain of the medial ligament. It develops in individuals who employ an incorrect throwing technique. The symptoms are cumulative, increasing with throwing and decreasing and resolving with rest. Treatment consists in improving the throwing technique. Local anaesthetic injected into the tender area produces complete but temporary relief. Hydrocortisone may produce partial or complete relief. 3. A second type of "javelin elbow" occurs in expert throwers and is the result of hyperextension of the elbow at the end of the throw, causing an injury to the tip of the olecranon. The symptoms are the result of a single throw or "mal-throw" and are completely disabling. They resolve with rest but tend to recur. If the tip of the olecranon is fractured excision of the fragment completely relieves the symptoms

At the time of publication sixty-three additional patients have been fitted with the patellar tendon bearing prosthesis. Twenty of these were new amputees, and forty-three were old amputees who had previously worn a conventional limb. Of this group, nine were considered failures. The contra-indications for fitting now include: 1) coincident knee derangement such as cruciate or collateral ligament laxity (the trauma that causes the amputation often produces knee injuries as well; in this event the side irons of the conventional prosthesis help to support the knee); 2) scars in the popliteal fossa, such as those produced by exploration of the popliteal vessels; 3) marked variation in stump size such as in rapidly growing children or obese people; and 4) labourers obliged to work on rough ground, which places additional strain on the knee

Aims

Commonly performed unicompartmental knee arthroplasty (UKA) is not designed for the lateral compartment. Additionally, the anatomical medial and lateral tibial plateaus have asymmetrical geometries, with a slightly dished medial plateau and a convex lateral plateau. Therefore, this study aims to investigate the native knee kinematics with respect to the tibial insert design corresponding to the lateral femoral component.

Objectives

Prosthetic joint infection (PJI) is the most common cause of arthroplasty failure. However, infection is often difficult to detect by conventional bacterial cultures, for which false-negative rates are 23% to 35%. In contrast, 16S rRNA metagenomics has been shown to quantitatively detect unculturable, unsuspected, and unviable pathogens. In this study, we investigated the use of 16S rRNA metagenomics for detection of bacterial pathogens in synovial fluid (SF) from patients with hip or knee PJI.

One hundred normal fingers were dissected and arthrographs obtained by injection of a chromopaquegelatin mixture, allowing comparison between the radiographic and macroscopic configuration of the synovial capsule. Synovial recesses protruding from each side of every metacarpo-phalangeal joint were found in relation to the collateral ligaments and corresponding exactly with the site of radiological erosions. A group of bursae lying on the superficial aspect of collateral ligaments were also demonstrated. A rudimentary infra-articular meniscus was found. The results of examination of the insertions of the interossei showed differences from traditional descriptions. The cause of rheumatoid deformity was suggested to be the rheumatoid process arising in the lateral recesses and lateral bursae, weakening the collateral ligaments, which give way in the directions of the deforming forces. These are derived from the long flexor tendons, which were shown to exert an ulnar and volar strain on the metacarpo-phalangeal joint of every finger during grip

1. The duration of Legg-Perthes' disease seems somewhat shortened by abduction weightbearing plaster treatnlent. The average age of onset of our sixty patients at the start of this treatment was seven years nine months. The patients were treated in abduction plasters for an average of nineteen months. 2. The contour of the femoral head in relation to the acetabulum is better preserved than after our previous methods of treatment. We have evaluated our cases by the method of Mose, by the epiphysial index of Eyre-Brook and the epiphysial quotient of Sjovall, and by the centre/edge angle of Wiberg. 3. There was no undue influence on the growing epiphysis and no evidence of ligamentous strain. 4. With this type of protected weight-bearing, the patients were kept active when both hips were affected. 5. No patient with unilateral disease showed Legg-Perthes' changes on the opposite side while under treatment or at follow-up. 6. The children were able to be at home and to attend school

1. There seem to be two distinct methods of destruction of the foot, once pain sensibility has been lost: the first is a slow erosion and shortening associated with perforating ulcers under the distal weight-bearing end of the foot. The second is a proximal disintegration of the tarsus in which mechanical forces often determine onset and progress of the condition. 2. Once the tarsus begins to disintegrate it is difficult to halt the rapid destruction of the foot. 3. It is possible to detect early stages of this condition in time to take preventive measures. Routine palpation of anaesthetic feet will reveal patches of warmth localised to bones and joints which are in a condition of strain. Radiographs of such feet and a study of posture and gait may define early changes which point to one of several possible patterns of disintegration which may follow. 4. These patterns are described and discussed and suggestions made for preventive and corrective measures

1. Recurrence of deformity after operations for drop foot is often associated with opening of the front of the ankle joint: this has previously been regarded as a complication of the operation. 2. This study of sixty paralytic drop feet treated conservatively reveals that this laxity was in fact present in no less than 43 per cent. 3. The laxity is most commonly found when the calf muscle is strong and it can occur within a year of the onset of the paralysis. It is not always prevented by wearing a toe-raising spring. 4. Such anterior laxity may well be a common cause of failure of many of the standard operations for drop foot. 5. Before operation for drop foot is undertaken a lateral radiograph of the ankle should be taken in forced plantar-flexiori. If this demonstrates anterior laxity any standard operation is unlikely to succeed unless the anterior fibres of the collateral ligaments are protected from strain by simultaneous tendon transplantation or unless the ankle is included in the arthrodesis

1. If a vertical load is applied to the head of the femur parallel to its shaft, the upper cortex is stretched and the lower cortex is compressed. The neck breaks from the upper subcapital border to the lesser trochanter. This type of fracture is rarely found clinically. 2. If a compressive force is applied to the area between head and greater trochanter while the head is loaded vertically, a transverse fracture of clinical appearance is produced. If this axial pressure acts along the part of the neck above the central axis a subcapital comminuted fracture results. If the pressure acts below the central axis the result is a transcervical fracture. 3. Strain gauge experiments have shown that axial compression within the upper segment of the neck is produced by the abductor muscles of the hip. Adductor muscles produce a low axial compression. It is suggested that muscular action at the time of injury influences the type of fracture produced by the injury

1. Sixty-five cases of medial fracture of the femoral neck treated by substitution of the head by an acrylic prosthesis have been studied. 2. In general, the long-term clinical results of prosthetic arthroplasty after fresh fractures have been disappointing. The method has given slightly better results in the treatment of old fractures. 3. In view of the almost perfect results obtained after successful Smith-Petersen nailing in the presence of an adequate blood supply to the femoral head, it seems unjustifiable to abandon this principle for immediate substitution with an acrylic femoral head. Nevertheless it is believed that an arthroplasty of this type is justified in fractures seen late, and in fresh subcapital fractures when the fracture is irreducible. If a prosthesis is to be used, more protection for the stump of the neck against the strain of weight bearing is essential; a simple head prosthesis is inadequate, and a head with either a neck extension or an intramedullary prolongation may give better results

1. Various types of fracture of the femoral neck represent different stages of one and the same displacing movement. 2. The displacement first produces an "abduction fracture" and terminates in an "adduction fracture," passing through the stage of an " intermediary fracture" which is less well recognised. 3. These three types of fracture occur in response to the same injury and they differ only in the degree of displacement. 4. It is a mistake to believe that in " adduction fractures" the femoral head lies medially to the collum : it lies posteriorly. 5. "Impaction" is no more than the first stage of displacement of fractures in which there is limited displacement, with contact still maintained between the fragments. 6. An "impacted fracture" is not necessarily stable—if there is additional strain it may progress to the next stage of a displaced and unstable fracture. 7. These principles apply not only to fractures of the femoral neck but to all other fractures at the ends of long bones