The alkaline phosphatase activity of pre-osseous tibial cartilage of rachitic bone stored in the deep freeze for two weeks at -25 degrees centigrade was only slightly less than that of fresh controls from the same animals. The deep frozen pre-osseous tissue did not calcify in in vitro calcifying media containing either inorganic phosphorus or organic phosphate ester. The fresh controls calcified equally well in both media. In addition, after deep-freeze storage the tissue hydrolysed the organic phosphate to the same degree as did the fresh tissue. Bones heated at 65 degrees centigrade will calcify in vitro after calcium chloride treatment despite the destruction of phosphatase activity. It appears unlikely that a relationship exists between alkaline phosphatase and the minimal system required for calcification of pre-osseous cartilage in vitro. These findings do not exclude the possibility that alkaline phosphatase plays some critical role in vivo

We have observed damage to the labrum as a result of repetitive acetabular impingement in non-dysplastic hips, in which the femoral neck appears to abut against the acetabular labrum and a non-spherical femoral head to press against the labrum and adjacent cartilage. In both mechanisms anatomical variations of the proximal femur may be a factor. We have measured the orientation of the femoral neck and the offset of the head at various circumferential positions, using MRI data from volunteers with no osteoarthritic changes on standard radiographs. Compared with the control subjects, paired for gender and age, patients showed a significant reduction in mean femoral anteversion and mean head-neck offset on the anterior aspect of the neck. This was consistent with the site of symptomatic impingement in flexion and internal rotation, and with lesions of the adjacent rim. Furthermore, when stratified for gender and age, and compared with the control group, the mean femoral head-neck offset was significantly reduced in the lateral-to-anterior aspect of the neck for young men, and in the anterolateral-to-anterior aspect of the neck for older women. For patients suspected of having impingement of the rim, anatomical variations in the proximal femur should be considered as a possible cause

We describe a new method of biological repair of osteochondral defects. In rabbit knees an osteochondral defect was reconstructed with a callo-osseous graft made of a superficial sheet of medullary fracture callus attached to a base of cancellous bone. This was taken from the iliac bone of the same animal which had been osteotomised ten days earlier. The reparative tissues were evaluated for 24 weeks by quantitative histology, biochemical analysis of the uronic acid content, and immunohistochemical staining of collagen constituents. The callo-osseous graft provided significantly faster and better repair of the articular surface than an untreated defect or a callo-osseous graft in which the cells had been devitalised by irradiation before transplantation. Our findings indicate that the callo-osseous graft contributes to the repair process by providing both favourable extracellular matrices and pluripotential mesenchymal cells. Our study tested the hypothesis that early medullary callus generates hyaline cartilage instead of bone after transfer to an articular surface

Aim

Osteoarthritis (OA) is caused by complex interactions between genetic and environmental factors. Epigenetic mechanisms control the expression of genes and are likely to regulate the OA transcriptome. We performed integrative genomic analyses to define methylation-gene expression relationships in osteoarthritic cartilage.

Surgical dislocation of the hip is rarely undertaken. The potential danger to the vascularity of the femoral head has been emphasised, but there is little information as to how this danger can be avoided. We describe a technique for operative dislocation of the hip, based on detailed anatomical studies of the blood supply. It combines aspects of approaches which have been reported previously and consists of an anterior dislocation through a posterior approach with a ‘trochanteric flip’ osteotomy. The external rotator muscles are not divided and the medial femoral circumflex artery is protected by the intact obturator externus. We report our experience using this approach in 213 hips over a period of seven years and include 19 patients who underwent simultaneous intertrochanteric osteotomy. The perfusion of the femoral head was verified intraoperatively and, to date, none has subsequently developed avascular necrosis. There is little morbidity associated with the technique and it allows the treatment of a variety of conditions, which may not respond well to other methods including arthroscopy. Surgical dislocation gives new insight into the pathogenesis of some hip disorders and the possibility of preserving the hip with techniques such as transplantation of cartilage

Radiographs of 155 Indian children were examined to identify the acetabular changes which occur in Perthes' disease. These changes included osteoporosis of the acetabular roof, irregularity of contour, premature fusion of the triradiate cartilage, hypertrophy of articular cartilage and changes in dimensions. These changes tended to be more marked in older children and when more than half of the femoral epiphysis was involved. Comparison with 25 cases of Perthes' disease from Liverpool showed the same picture. Several of the acetabular changes noted during the active stages were also seen in a series of 24 adult hips after Perthes' disease. Radio-isotope scans of the hips of 27 children with Perthes' disease showed a consistently increased uptake in the acetabulum on the affected side, indicative of a local increase in vascularity and metabolic activity. It was possible to postulate a working model for the pathogenesis of all the acetabular changes. A number of statistical correlations suggest that most of the changes have a bearing on the final outcome

Six cases of osteochondritis dissecans patellae have been studied in five patients in an attempt to clarify the aetiology and prognosis. Assessment of the results of treatment was performed using a standard protocol. The thirty-four previous case reports in the literature are reviewed. In four of the five patients symptoms began after flexing the knee under load and three showed patellar subluxation on tangential radiographs. Thus, repetitive shearing stress on the patellar surface is thought to be an important aetiological factor. The indication for operation is a loose osteochondral fragment either wholly or partly detached from the articular surface of the patella. Vertical excision of the affected area of articular cartilage with drilling of the underlying bone gave two "good" and two "excellent" results. Healing of the drilled area and maintenance of the cartilage space was seen in radiographs of all four cases so treated. This simple method of treatment, which probably causes filling of the defect in the surface by fibrocartilage, is recommended

This paper describes a study in the human femur of the relationship between cell division in growth cartilage and overall bone growth. Growth rates for the distal femur from birth to eighteen years were determined from serial radiographs available from the Harpenden Growth Study; An average of 1-4 cm/year was found for the ages of five to eight years. The development of the growth plate is illustrated in a series of photomicrographs of femur sections. These sections were also used for quantitative histology; The length of the proliferation zone was estimated from cell counts to be twenty-four cells per column. On the basis of this value and the measured growth rate, an approximate mean cycle time of twenty days was found for the proliferating cells of the human growth plate. Since the corresponding cycle time is two days for rodent growth plates, which also have a different structure, it is unwise to extrapolate the findings in this tissue from mouse to man

1. Experimental work with piglets supports the theory that diminished blood supply to the femoral head not only causes necrosis of the epiphysis but also a decrease in cartilage cell production in the germinal layer of the epiphysial plate, thus causing decreased longitudinal bone growth. Appositional growth continues in the metaphysis because its blood supply remains intact or, at least, is less impaired. The resulting disturbance of the normal remodelling must lead to a short wide neck such as occurs in Legg-Perthes' disease. 2. Measurements were made of the length and width of the femoral neck on radiographs of forty patients with Legg-Perthes' disease. The results showed that the degree of shortening and widening is related to the extent of structural change in the head. 3. Repeated measurements in the early stages of the active disease may permit an early prognosis which may be of great assistance in selecting the treatment suitable to each patient. The financial assistance of the Ontario Society for Crippled Children is gratefully acknowledged

1. Serial slices of articular cartilage obtained at necropsy from apparently normal femoral condyles of individuals between the ages of twenty-six and sixty were examined chemically, by electron microscopy and for permeability. 2. The most superficial layer was shown by chemical analysis and electron microscopy to have the highest collagen content, which fell sharply with distance from the articular surface. On the other hand the glycosaminoglycan content was very low in the superficial layers but increased with depth. This variation was found in all specimens tested but the absolute levels of collagen and of glycosaminoglycans were widely different. There was no correlation of chemical composition with age. 3. Collagen fibrils in the superficial layer were of much smaller diameter than in the deeper zones. 4. Hydraulic permeability was shown to depend more on glycosaminoglycan than on collagen content, although it varied inversely with both these factors. 5. The results obtained demonstrate clearly the close relation between the physical properties of cartilage and its chemical composition

1. The three age types of acute haematogenous osteomyelitis are conditioned in their respective clinical features by the differing nature of their vascular bone pattern. 2. In the infant the condition causes severe and often permanent epiphysial damage and joint infection, a large involucrum but only transient damage to the shaft and metaphysis. 3. In the child the condition is responsible for extensive cortical damage with involucrum formation, but, except for some stimulation of growth, permanent damage to the growth cartilage and to joints is exceptional. Chronicity of the disease is rare if treatment has been effective. 4. In the adult acute osteomyelitis of the long bones is rare. It causes very frequent joint infection; the cortex is absorbed instead of sequestrating. The whole of the bone is invaded and frequently leaves chronic infection in the bone marrow. 5. The vascular characteristics of the bones in each age group and their relation to the onset of infection are described. 6. Some general directives for management based on these facts are suggested

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

Three elderly sibling dwarfs are reported from a large and otherwise normal family. Their condition is an unusual and irregular form of cartilaginous defect, combined with club-feet, and bearing some resemblance to the Morquio type. A brief consideration of the literature of the generahised developmental bony syndromes shows confusion of thought and nomenclature. A plea is therefore made for simplification and a rational and simple grouping of these conditions is attempted. It seems particularly desirable that many confusing names for particular syndromes should be scrapped (for example, dyschondroplasia, chondro-osteodystrophy), although quite evidently the terms achondroplasia and osteogenesis imperfecta must remain because of their long-standing and general usage. Incidentally I have suggested elsewhere (Jackson 1951) that the name cleido-cranial dysostosis should be dropped, because it tends to lead the investigator away from the clinically more important lesions in the teeth and the cartilage bones of the pelvis and legs. It seems reasonable to confine the nomenclature of these various syndromes to the names used in the above classification, or something on those lines

Objectives

Little is known about tissue changes underlying bone marrow lesions (BMLs) in non-weight-bearing joints with osteoarthritis (OA). Our aim was to characterize BMLs in OA of the hand using dynamic histomorphometry. We therefore quantified bone turnover and angiogenesis in subchondral bone at the base of the thumb, and compared the findings with control bone from hip OA.

After a severe ankle sprain the incidence of residual complaints, particularly on the medial side of the joint, is high. We studied a consecutive series of 30 patients who had operative repair of acute ruptures of lateral ligaments. During operation, arthroscopy revealed a fresh injury to the articular cartilage in 20 ankles, in 19 at the tip and/or anterior distal part of the medial malleolus as well as on the opposite medial facet of the talus. In six patients, a loose piece of articular cartilage was found. We conclude that in patients with a rupture of one or more of the lateral ankle ligaments after an inversion injury, an impingement occurs between the medial malleolus and the medial facet of the talus. Patients with a lesion of the lateral ankle ligament caused by a high-velocity injury (a faulty landing during jumping or running) had a higher incidence of macroscopic cartilage damage (p < 0.01), medially-located pressure pain (p = 0.06) and medially-located complaints at one-year follow-up (p = 0.02) than those with a low-velocity injury (a stumble)

Objectives

To compare the effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament (ACL) reconstruction animal model.

Aims

There is little information about how to manage patients with a recurvatum deformity of the distal tibia and osteoarthritis (OA) of the ankle. The aim of this study was to evaluate the functional and radiological outcome of addressing this deformity using a flexion osteotomy and to assess the progression of OA after this procedure.

Cadaver knee joints were mounted so that life-like forces of weight-bearing were simulated. The patello-femoral contact areas were defined under load throughout the range of movement by the dye method. During movement from extension to 90 degrees of flexion a band of contact sweeps across the patella from inferior to superior pole, but the odd facet makes no contact. At about 135 degrees of flexion separate medial and lateral contact areas form, the medial one limited to the odd facet. From extension to 90 degrees of flexion the patella holds the quadriceps tendon away from the femur, but in further degrees of flexion an extensive "tendo-femoral" contact area forms. Between 90 degrees and 135 degrees of flexion the patella rotates and the ridge between the medial and odd facets engages the femoral condyle. The odd facet is shown to be a habitual non-contact area and the ridge to be subject to high load, observations which correlate with cartilage lesions described in Part 2 of the paper

We compared the changes in the ratio of type-I and type-II collagen in monolayer cultures of human articular chondrocytes (HAC). HAC were isolated from samples of cartilage from normal joints and cultivated in monolayer for up to 46 days. Expression of collagen type-I and type-II was determined by immunocytochemistry, Western blotting, and the nested reverse transcription polymerase chain reaction (RT-PCR), and quantified by real-time PCR. The transition from a spherical morphology to the flattened morphology of an anchorage-dependent culture was accompanied by a rapid change in the collagen phenotype with the replacement of collagen type II by collagen type I. This was confirmed by immunocytochemistry and Western blotting between days 21 and 28. Using techniques for the analysis of gene transcription (nested RT-PCR and real-time PCR), a complete switch of collagen gene expression was not observed. Expression of collagen type I increased 100-fold during the culture time. That of collagen type II was found during the entire period and decreased more than 100-fold. The main finding was that expression of the genes encoding collagen type I and II was highly time-dependent and the ratio of collagen type II to I (CII/CI), defined as an index of cell differentiation, was significantly higher (215- to 480-fold) at the beginning of the culture. At the end of the experimental culture time, ratios between 0.1 and 1 were reached