1. Primary reticulum-cell sarcoma of bone arises from the reticulo-histiocytic elements of bone marrow. 2. The authors have studied ten cases of primary reticulum-cell sarcoma of bone, and have compared the clinical, pathological and radiographic features with those of thirty-five cases of Ewing's sarcoma. 3. In their microscopic studies Hortega's staining techniques were used in addition to orthodox methods. 4. There are histological differences between a reticulum-cell sarcoma and Ewing's sarcoma. 5. Certain clinical and radiographic features help the differentiation between the two tumours. 6. The progress and treatment of the reticulum-cell sarcoma are reviewed in detail

Objectives

Intra-articular injections of local anaesthetics (LA), glucocorticoids (GC), or hyaluronic acid (HA) are used to treat osteoarthritis (OA). Contrast agents (CA) are needed to prove successful intra-articular injection or aspiration, or to visualize articular structures dynamically during fluoroscopy. Tranexamic acid (TA) is used to control haemostasis and prevent excessive intra-articular bleeding. Despite their common usage, little is known about the cytotoxicity of common drugs injected into joints. Thus, the aim of our study was to investigate the effects of LA, GC, HA, CA, and TA on the viability of primary human chondrocytes and tenocytes in vitro.

Thirteen total hip replacements with titanium alloy femoral components required revision for loosening at an average of two years after implantation. At revision the soft tissues around the implant were darkly stained and a proliferative membrane had invaded the cement-bone interface. The femoral components showed polishing of parts of their shot-blasted surfaces. Histology showed a fibroblastic reaction with abundant titanium lying free and within histiocytes, and a scanty foreign-body giant-cell reaction. Surface analysis of the removed femoral components and chemical analysis of the excised tissues is described. Tissue reaction in response to the metal-wear debris may have contributed to the early failure of these implants

1. The arrangement of collagen fibres in the secondary osteones in human femora and tibiae has been examined. The fibres were observed in paraffin sections stained by Weidenreich's method. 2. Three fibre patterns have been observed. They differ from one another in the relative numbers of longitudinal and circumferential fibres which they contain, and in the degree of lamellation which they exhibit. 3. The incidence of the three fibre patterns has been correlated with the relative ages of the regions of bone in which they occur. 4. The possibility of a correlation between variations in fibre pattern and certain recent microradiographic observations is discussed

Aims

This pilot study tested the performance of a rapid assay for diagnosing prosthetic joint infection (PJI), which measures synovial fluid calprotectin from total hip and knee revision patients.

Full thickness samples of articular cartilage were removed from areas of chondromalacia on the medial and "odd" facets of the patellae of 21 adults and examined by histology, autoradiography and electron microscopy. Surface fibrillation, loss of superficial matrix staining and reduced 35SO4 labelling was seen, with little change in the deep zone. Ten cases showed "fibrous metaplasia" of the superficial cartilage with definite evidence of cell division and apparent smoothing of the surface. Scattered chondrocyte replication appeared to occur in the surrounding intact cartilage. The findings suggest that early lesions in chondromalacia patellae may heal either by cartilage or fibrous metaplasia and that this may account for the resolution of clinical symptoms

We have performed a prospective, single-surgeon study analysing the histological results of autologous chondrocyte implantation. Fourteen patients underwent autologous chondrocyte implantation of the knee and were evaluated at one year by clinical assessment and arthroscopy. Standard staining was used to examine the sections. In addition, in situ hybridisation was used to establish type-IIa and type-IIb collagen mRNA expression and immunolocalisation techniques demonstrated the positions of type-II and type-X collagen. Eight patients regenerated hyaline cartilage and also contained type-X collagen in the deepest layers and type-II collagen in the deep layers. Three demonstrated fibrocartilage and had type-II collagen in the deep layers. In situ hybridisation revealed that all 14 samples had the potential to express both type-IIa and type-IIb collagen. We have shown that one year after the initial implantation chondrocytes are capable of producing type-II collagen and that they continue to proliferate and mature

1. Degenerative arthritis has been produced consistently in adult rabbits by the injection of the proteolytic plant enzyme papain into the hip joint. Arthritic changes were recognisable radiographically after six weeks. 2. A progression of changes occurred, from loss of acid mucopolysaccharide staining in the matrix, fibrillation, fissuring and erosion of articular cartilage with death of chondrocytes in the weight-bearing areas, to secondary bony changes of subchondral sclerosis, occasional cysts and osteophyte formation. 3. Synovial inflammation occurred with accumulation of cartilage and bone debris in the inferior capsule and later capsular thickening. 4. It is suggested that this arthritis is sufficiently similar to human osteoarthritis to be useful as a model for further studies of the pathogenesis of the disease and the effects of different methods of treatment

Compartment syndrome is a unique form of ischaemia of skeletal muscle which occurs despite patency of the large vessels. Decompression allows the influx of activated leucocytes which cause further injury. Vitamin C is a powerful antioxidant which concentrates preferentially in leucocytes and attenuates reperfusion-induced muscle injury. We have evaluated the use of pretreatment with oral vitamin C in the prevention of injury caused by compartment syndrome in a rat cremasteric muscle model. Acute and delayed effects of pretreatment with vitamin C were assessed at one and 24 hours after decompression of compartment syndrome. Muscle function was assessed electrophysiologically. Vascular, cellular and tissue inflammation was assessed by staining of intercellular adhesion molecule-1 (ICAM-1) and by determination of the activity of myeloperoxidase (MPO) in neutrophils and tissue oedema. Compartment syndrome impaired skeletal muscle function and increased the expression of ICAM-1, activity of MPO and muscle weight increased significantly. Pretreatment with vitamin C preserved muscle function and reduced the expression of ICAM-1, infiltration of the neutrophils and oedema

1. A hypothesis outlining an auto-immune mechanism for antibody production against autogenous nucleus pulposus is presented. 2. Auto-antibodies to autogenous nucleus pulposus have been experimentally produced in rabbits. 3. These antibodies are cell-bound within lymphoid cells and are greatest in primary lymph nodes. This antibody is demonstrated by a positive pyronin reaction. 4. Lymphoid cells fixed in Carnoy's fluid and stained for pyronins also show a distinct natural yellow fluorescence. This fluorescence occurs only in the cytoplasm of those cells which are pyronin-positive and presumably producing antibody. 5. The lymph node phase of the reaction is greatest at four days and is sustained for three weeks. A secondary generalised lymph node response occurs in all lymph nodes at six weeks

1. Rusty staining of the synovial membrane is the gross manifestation of loading of phagocytic synovial-lining cells and of macrophages in the stratum synoviale with haemosiderin. 2. Absorption of blood effused into the joint cavities is the commonest cause of such synovial pigmentation. 3. Obvious discolouration of the synovial tissues usually follows only after repeated haemarthroses, in such conditions as haemophilia, synovial tumour and in some cases of chronic rheumatoid arthritis. 4. An identical naked-eye appearance is seen in multiple joints of patients with generalised haemochromatosis. 5. In haemochromatosis the iron-containing pigment tends to be confined to the surface layer of cells of the synovial membrane. 6. The presence of haemosiderin in synovial cells, per se, leads to no disability of the joint and is unaccompanied either by inflammatory reaction or fibrosis. Arthritis in a patient with haemochromatosis is fortuitous

Injury to muscles is very common. We have previously observed that basic fibroblast growth factor (b-FGF), insulin growth factor type 1 (IGF-1) and nerve growth factor (NGF) are potent stimulators of the proliferation and fusion of myoblasts in vitro. We therefore injected these growth factors into mice with lacerations of the gastrocnemius muscle. The muscle regeneration was evaluated at one week by histological staining and quantitative histology. Muscle healing was assessed histologically and the contractile properties were measured one month after injury. Our findings showed that b-FGF, IGF and to a less extent NGF enhanced muscle regeneration in vivo compared with control muscle. At one month, muscles treated with IGF-1 and b-FGF showed improved healing and significantly increased fast-twitch and tetanus strengths. Our results suggest that b-FGF and IGF-1 stimulated muscle healing and may have a considerable effect on the treatment of muscle injuries

We studied the early cartilage changes in osteoarthritis, examining the most normal appearing articular cartilage from the hips of 17 patients. Normal appearing cartilage from five patients treated for fractures was used as control material. Two different types of clone were found. The first had increased staining for proteoglycan and was thought to have been engaged in the synthesis of matrix. The other type was associated with a severe deficiency of proteoglycan, matrix streaks and evidence of degradation and phagocytosis of matrix components. Immunohistochemistry demonstrated large amounts of chondroitin 4 and 6 sulphate about the synthetic-type clones, and little or no reactivity about the degenerative clones which lay more superficially and were associated with matrix destruction. Clones appeared to be engaged in either matrix synthesis or its destruction. The disease process of osteoarthritis appeared to begin at the surface of the articular cartilage

Objectives

The purpose of this study was to examine the bactericidal efficacy of hydrogen peroxide (H₂O₂) on Cutibacterium acnes (C. acnes). We hypothesize that H₂O₂ reduces the bacterial burden of C. acnes.

Three palmar wrist ligaments from fresh human cadavers were dissected from the proximal to the distal insertions and stained to identify the mechanoreceptors. Golgi organs, Pacinian corpuscles, Ruffini endings and free nerve endings were present in all three ligaments. In the radial collateral and radiolunate ligaments they were found in increased density towards the proximal and distal insertions. A more uniform distribution was found in the radioscaphocapitate ligament which has attachments to three bones. The palmar wrist ligaments may have a significant sensory role in maintaining the stability of the wrist and in controlling its movement. Although technically difficult, the surgical repair of traumatic wrist defects should attempt to preserve the innervation of the ligaments, shown to be mainly near bony attachments. This may allow improvement in postoperative outcomes by preserving some proprioception. In some painful post-traumatic or degenerative conditions, however, denervation may be advantageous

We studied the presence of anabolic growth factors in human herniated intervertebral discs (IVD) using a reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. Messenger RNA (mRNA) was isolated from the nucleus pulposus using oligo (dT). 25. superparamagnetic beads and probing with gene-specific primers in RT-PCR. mRNA coding for TGF-α (3/10), EGF (0/10), TGF-β1 (0/10) and TGF-β3 (2/10) or the EGF receptor (EGF-R; 0/10) and TGF-β type-II receptor (0/10) was found only occasionally. Beta-actin was always present and positive sample controls confirmed the validity of the RT-PCR assay. These RT-PCR findings were confirmed using immunohistochemical staining of EGF and TFG-β, whereas TGF-α protein was always found associated with discocytes. We conclude that the nucleus pulposus of the herniated IVD is vulnerable to proteolytic degradation and depletion of proteoglycans due to the lack and/or low production of anabolic growth factors/receptors which could increase the local synthesis of the extracellular matrix

Aims

Biopsy of the periprosthetic tissue is an important diagnostic tool for prosthetic joint infection (PJI) as it enables the detection of the responsible microorganism with its sensitivity to antibiotics. We aimed to investigate how often the bacteria identified in the tissue analysis differed between samples obtained from preoperative biopsy and intraoperative revision surgery in cases of late PJI; and whether there was a therapeutic consequence.

Chondrocytes of the growth plate are generally assumed to undergo apoptosis, but the mechanisms which induce this cell death are not known. The Fas receptor is a mediator of the apoptotic signal in some systems. We studied its expression in situ in growth plates of rabbits aged from five to 20 weeks. In addition, we investigated the immunolocalisation in the growth plates of the bone proteins, osteonectin and osteocalcin, and the changes in their expression with age. The Fas-positive chondrocytes were found mostly in the hypertrophic zone, as were the osteonectin-positive and osteocalcin-positive cells. The percentage of Fas-positive cells increased with age whereas little change was found in the number of osteonectin-positive and osteocalcin-positive chondrocytes. Many of the Fas-positive chondrocytes were also TUNEL-positive. This strongly suggests that apoptosis in the growth plate is mediated through the Fas system. Double immunostaining for osteocalcin and Fas showed that not all hypertrophic chondrocytes were of the same cell type. Some chondrocytes stained for osteocalcin only, others for Fas only, while some were positive for both

Of 935 consecutive patients referred with shoulder pain, 50 fitted the criteria for primary frozen shoulder. Twelve patients who failed to improve after conservative treatment and manipulation had excision of the coracohumeral ligament and the rotator interval of the capsule. The specimens were examined histologically, using special stains for collagen. Immunocytochemistry was performed with monoclonal antibodies against leucocyte common antigen (LCA, CD45) and a macrophage/synovial antigen (PGMI, CD68) to assess the inflammatory component, and vimentin and smooth-muscle actin to evaluate fibroblasts and myofibroblasts. Our histological and immunocytochemical findings show that the pathological process is active fibroblastic proliferation, accompanied by some transformation to a smooth muscle phenotype (myofibroblasts). The fibroblasts lay down collagen which appears as a thick nodular band or fleshy mass. These appearances are very similar to those in Dupuytren's disease of the hand, with no inflammation and no synovial involvement. The contracture acts as a check-rein against external rotation, causing loss of both active and passive movement