In dogs, resection of a length of the ulna equal to twice the diameter of the mid-shaft leaves a defect which consistently fails to unite. In response to an implant of 100 mg of bovine bone morphogenetic protein (BMP), the defect becomes filled by callus consisting of fibrocartilage, cartilage and woven bone within four weeks. The cartilage is resorbed and replaced by new bone in four to eight weeks. Woven bone is then resorbed, colonised by bone marrow cells and remodelled into lamellar bone. Union of the defect is produced by 12 weeks. Control defects filled with autogeneic cortical bone chips unite after the same period. In regeneration induced by bone morphogenetic protein (BMP) and in repair enhanced by bone graft, union depends upon the proliferation of cells within and around the bone ends. Our working hypothesis is that BMP induces the differentiation of perivascular connective tissue cells into chondroblasts and osteoprogenitor cells and thereby augments the process of bone regeneration from the cells already present in the endosteum and periosteum

1. Two inches of lengthening may be gained in the femur, and three inches in the tibia and fibula, without complication. 2. More than this may be secured at the risk of temporary external popliteal paresis. 3. Lengthening of the tibia and fibula is more certain and more easy to control than lengthening of the femur. 4. Traction, and counter-traction through the bone, with complete lateral rigidity, are essential to success. 5. In applying this technique to the femur there is a danger of knee stiffness. The farther from the knee the skeletal traction pins are inserted, the less is the risk. The operation should therefore be planned as high as possible in the shaft of the femur. 6. The most delicate structure, and the one least tolerant of stretching, is the external popliteal nerve. 7. An oblique osteotomy, started by closely spaced drill-holes, is the best. 8. Certain vascular complications experienced by other surgeons are attributable to subperiosteal bone exposure, and to dividing the periosteum and fascial structures transversely

The parameters of cellular proliferation and growth in the growth plates of immature rats were measured after unilateral tibial osteotomy and used to calculate growth rates. Distal osteotomy of one tibia was followed by a bilateral increase in the calculated growth rate of the distal growth plates. However, the ipsilateral distal growth plate grew faster than the contralateral between 12 and 18 days after operation, which appeared to be related to increased cell proliferation and height. Proximal osteotomy led to an increase in growth rates proximally which was more marked on the contralateral side. The lesser response of the ipsilateral growth plate may have been due to local impairment of blood supply, or to greater local release of metabolites after bony damage. Distal tibial osteotomy gave similar results to circumferential release of the distal tibial periosteum. Proximal osteotomy, however, produced a relative impairment of growth on the operated side. This may be of importance in the correction of childhood deformities associated with inequality of leg length

We used a rabbit model to investigate the mechanism by which the angulation of fractures is corrected in children. We produced a transverse proximal tibial fracture in one leg of 12 eight-week-old New Zealand white rabbits and measured bone alignment and length and the patterns of bone growth and remodelling. The angle between the joint surfaces changed rapidly to correct the alignment of the limb as a result of asymmetrical growth of epiphyseal plates. In an adult with closed plates, the angle between the joint surfaces cannot therefore improve. The angle at the fracture itself showed slow improvement because of bone drift and the asymmetrical growth of the epiphyseal plates. Remodelling corrected the shape of the bone in the region of the fracture. Periosteal division on the convex side increased the growth of the epiphyseal plate on that side, thus slowing the correction. The effect was relatively small, providing an indication that factors other than the periosteum are important in inducing correction. External torsional deformities developed because of helical growth at the plate. This was probably caused by abnormal posture which induced a torque at the growth plate. Helical growth is the mechanism by which rotational deformities can occur and correct

We carried out limb lengthening in rabbits and then transplanted osteoblast-like cells derived from the tibial periosteum to the centres of distracted callus immediately after distraction had been terminated. Two weeks later the transaxial area ratio at the centre of the distracted callus and the bone mineral density (BMD) were significantly higher in the transplanted group, by 21% and 42%, respectively, than in the non-injected group or the group injected with physiological saline (p < 0.05). Callus BMD as a percentage of density in uninvolved bone was also significantly higher in the transplanted group (p < 0.05) than in the other two groups, by 27% and 20% in the second and fourth weeks, respectively (p < 0.05). Mechanically, the callus in the transplanted group tended to be stronger as shown by the three-point bending test although the difference in fracture strength was not statistically significant. Our results show that transplantation of osteoblast-like cells promotes maturity of the distracted callus as observed at the second and fourth weeks after lengthening. The method appears promising as a means of shortening the consolidation period of callus distraction and decreasing complications during limb lengthening with an external fixator

The aim of limb-salvage surgery in malignant bone tumours in children is to restore function and eradicate local disease with as little morbidity as possible. Allografts are associated with a high rate of complications, particularly malunion at the allograft-host junction. We describe a simple technique which enhances union of allograft to host bone taking advantage of the discrepancy in size between the adult allograft and the child’s bone. This involves lifting a flap of periosteum before resection from the host bone, which is then telescoped into the allograft medullary canal, which may require internal burring or splitting, for a distance of 1.5 to 2 cm and covering the bone junction with the periosteal flap. This is more stable than conventional end-to-end opposition. For each centimetre of telescoping the surface area available for bony union is increased more than three times. The periosteal flap also augments union. Additional surface fixation with a plate and screws is not necessary. We have used this technique in nine children, in eight of whom there was complete union at a mean of 16 weeks. Delayed union, associated with generalised limb osteoporosis, occurred in one. Early mobilisation, with weight-bearing by three weeks, was possible. There was only one fracture of the allograft

1. Three cases of infantile pseudarthrosis of the tibia treated successfully by delayed autogenous by-pass graft are reported. 2. The delayed autogenous graft is stouter, stronger and more easily handled and has enhanced osteogenic properties than a graft transferred immediately. 3. The by-pass graft commends itself, firstly, because it does not disturb the pseudarthrosis, which in consequence helps the immobilisation of the graft; secondly, because it is well embedded in healthy bone above and below, well away from the abnormal bone; thirdly, because it lies under compression and, ideally, is vertically disposed between the knee and the ankle; and fourthly, because there is no devitalising stripping of periosteum or introduction of foreign bodies. 4. Support to the grafted leg is needed for at least five years, but only by a polythene splint after four to six months. 5. With early grafting the deformity straightens out and shortening is overcome, as there is early return to normal use of the limb. 6. Prolonged follow-up is called for lest the basic lesion in the tibia should extend. 7. Fibrous dysplasia and similar fibrous lesions of bone account for many cases of infantile pseudarthrosis of the tibia. Many of these lesions are congenital and subsequently lead to fracture. 8. Postponement of surgery should not be countenanced

1 . Implants of heterogenous cartilage are known to excite a foreign body reaction in host tissues. In these experiments the way such implants hinder the spread of ossification across a fracture gap was studied. A segment of bone and periosteum was excised from both fibulae in twelve young grivet monkeys, and epiphysial cartilage from a four-day- old rat was implanted in the gap on the left side. The repair processes were investigated at intervals up to twenty-eight weeks. 2. On both sides the gaps were filled by fibrous tissue growing in from the adjacent muscle, and four weeks elapsed before callus started to form. Thereafter ossification across the gap was active on the right side, with bony union in seven or eight weeks. 3. On the left side the implant was slowly resorbed by macrophages and giant cells. Ossification made little headway in the gap after the seventh week. Remains of the implant were found up to the end of the period covered by the experiment. The ends of the fragments were united by fibrous tissue. 4. The fifth to the eighth week seemed to be a critical period, during which the implant and its surrounding inflammatory cells hindered chondrification and ossification and prevented fusion of the masses of callus at the ends of the fragments. 5. It is concluded that anything that impedes callus formation across the fracture line during this critical period may lead to non-union

1. A description is given of the pathology of a generalised skeletal disease characterised by a defect in the formation of the collagen fibres of the bone matrix—"fibrogenesis imperfecta ossium.". 2. Material from two cases, a woman of fifty-six and a man of sixty-four, was examined. All the samples of bone from both patients showed the same defect, which was severe in most of the specimens, and there was radiographic evidence of similar widespread bone changes in both cases. 3. The defect is clear-cut and striking histologically, provided that sections are examined with a polarising microscope, and/or by reticulin methods. 4. As a result of the defect in the bone matrix this fails to calcify, or calcifies imperfectly, showing wide osteoid borders as in severe osteomalacia. But the fibre defect separates it quite clearly from osteomalacia, in which the fibre structure of the osteoid tissue is normal. Moreover neither the biochemical findings (Case 2) nor the radiographic appearances correspond with those of osteomalacia. 5. The collagen fibre defect is confined to the bone matrix; no defect was found in the soft tissue collagen, and even the periosteum shows a normal fibre structure. 6. Both the clinical and the histological evidence indicate that the disease is not congenital, but was, in these two patients, apparently acquired during middle age. There was no family history of bone disease. 7. The cause of the condition is quite obscure. It is not inflammatory or neoplastic, nor is there histological or clinical evidence of a toxic origin. If it is a deficiency disease it is unlike any known vitamin or other chemical deficiency

Aims

The aim of this study was to investigate the efficacy of coccygectomy in patients with persistent coccydynia and coccygeal instability.

Aims

Liposomal bupivacaine (LB) as part of a periarticular injection protocol continues to be a highly debated topic in total knee arthroplasty (TKA). We evaluated the effect of discontinuing the use of LB in a periarticular protocol on immediate postoperative pain scores, opioid consumption, and objective functional outcomes.

Aims

CERAMENT|G is an absorbable gentamicin-loaded biocomposite used as an on-site vehicle of antimicrobials for the treatment of chronic osteomyelitis. The purpose of the present study was to investigate the sole effect of CERAMENT|G, i.e. without additional systemic antimicrobial therapy, in relation to a limited or extensive debridement of osteomyelitis lesions in a porcine model.

1 . The concept of the capsular mechanism of the shoulder joint with regard to recurrent anterior dislocation of the shoulder has been defined and a survey of the literature presented. 2. An anatomical, including an embryological, investigation of shoulder joints with special reference to the structure and function of the glenoid labrum and to the variations in the arrangement of the gleno-humeral ligaments and the synovial recesses of the anterior capsular mechanism is reported. The labrum, which is generally believed to be a consistent, fibrocartilaginous structure, is shown to be a redundant portion of capsular tissue and a continuation of the capsule as it attaches to the osseous glenoid rim. The fibrocartilaginous element is confined to a small transition zone at the capsular attachment in the great majority of cases. The great variability in the arrangement of the gleno-humeral ligaments and synovial recesses is stressed, and it is shown that an anterior pouch of variable size is present when the middle gleno-humeral ligament is attached to the scapular neck and not to the labrum. 3. The basic lesions of the anterior capsular mechanism found at operation for recurrent anterior dislocation of the shoulder in twenty-five consecutive cases using a modified Bankart procedure with a standard anterior approach to the joint are reported, and the findings are correlated with the results of the anatomical investigation. In most cases the lesions were found to be of the Bankart type with or without avulsion of the periosteum of the scapular neck. In four cases, however, the soft-tissue attachment to the anterior glenoid rim was intact; in those cases a large synovial pouch was present and the middle gleno-humeral ligament was either not discernible or it arose from the scapular neck. In all cases a postero-lateral notch on the humeral head was palpable and laxity of the subscapularis could be demonstrated. When measured, the joint capacity was always greatly augmented. 4. The present work shows, from a basic standpoint, that Bankart's original idea that the recurrent state was due to the failure of healing of the fractured fibrocartilaginous glenoid labrum is no longer tenable. 5. Finally, the anomalous attachment or the insufficient development of the middle gleno-humeral ligament in certain cases of recurrent anterior shoulder dislocation is shown to provide the anatomical basis for the recurrent state in these cases; this is the weak area in the antero-inferior part of the capsule which has been described in the literature for the past hundred years. Thus we have returned to the original view of Hippocrates

Aims

We hypothesized that the wide-awake local anaesthesia with no tourniquet (WALANT) technique is cost-effective, easy to use, safe, and reproducible, with a low learning curve towards mastery, having a high patient satisfaction rate. Furthermore, WALANT would be a suitable alternative for the austere and developing nation environments where lack of funds and resources are a common issue.

Aims

Our retrospective analysis reports the outcome of patients operated for slipped capital femoral epiphysis using the modified Dunn procedure. Results, complications, and the need for revision surgery are compared with the recent literature.

The experiments were performed to answer three main questions. These and our answers may be summarised as follows. What is the precise mechanism of healing of a raw bony surface in a joint? What cells are involved? Where do they originate?—In all the implant experiments and in the control series the fundamental mechanism of healing was similar. 1. A massive proliferation of fibroblasts occurred from the cut periosteum, from the cut joint capsule, and to a lesser extent from the medullary canal. 2. Fibroblasts grew centripetally in the first few weeks after operation, attempting to form a "fibroblast cap" to the cut bone end. 3. Fibroblasts of this cap near the cut bone spicules metamorphosed to become prechondroblasts, chondroblasts laying down cartilage matrix, and hypertrophied (alkaline phosphatase-secreting) chondrocytes lying in a calcified matrix. 4. This calcified cartilage matrix was invaded by dilated capillaries probably bearing osteoblasts which laid down perivascular (endochondral) bone. 5. Some of the cells of projecting bone spicules died and their matrix was eroded in the presence of many osteoclasts. 6. In the control experiments of simple excision of the radial head new bone was produced at the periphery only by processes (3) and (4). This sealed off the underlying peripheral cortical bone from the superficially placed peripheral articular surface of fibrocartilage. At about a year from operation the central portion of the articular surface was still formed of bare bone, or of bone spicules covered by a thin layer of irregularly arranged collagen fibres. The opposite capitular articular cartilage was badly eroded. Does the introduction of a dead cartilage implant over the raw bone end affect in any way the final constitution of the new articular surface?—In the implant experiments the new bone produced by processes (3) and (4) formed, after about a year, a complete cortical plate which entirely sealed off the cut end of the radius and left a superficially placed articular covering of smooth fibrocartilage, closely resembling a normal joint surface. The opposite capitular articular surface was normal. What is the final fate of such an implant?—Whale cartilage implants underwent replacement by fibroblasts and collagen fibres, and took about nine months to disappear. The cartilage of fixed autotransplants and homotransplants underwent similar gradual replacement, and took about the same time in each case. The dead bone, implanted in association with the cartilage in both cases, acted as a nidus for hyaline cartilage production by chondrocytes derived from fibroblasts. This cartilage underwent endochondral ossification. This observation suggests that induction by non-cellular osseous material is a factor in chondrification and ossification. All the implants functioned as temporary articular menisci or in some cases as temporary radial articular surfaces. They were always replaced by a permanent fibrocartilaginous meniscus, or a fibrocartilaginous articular surface. An implant did, in fact, always act as a temporary protecting cap and mould for the subjacent growth offibroblasts which was necessary for the production of a satisfactory new joint surface

Aims

Treatment of chronic osteomyelitis (COM) for young patients remains a challenge. Large bone deficiencies secondary to COM can be treated using induced membrane technique (IMT). However, it is unclear which type of bone graft is optimal. The goal of the study was to determine the clinical effectiveness of bone marrow concentrator modified allograft (BMCA) versus bone marrow aspirate mixed allograft (BMAA) for children with COM of long bones.