1. Study of 200 cases investigated by pneumarthrography has shown that the introduction of air or oxygen into the knee joint is followed by a specific reaction characterised by transient localised eosinophilia in synovial membrane and synovial fluid. 2. Complications after meniscectomy seem to be more frequent when operation is performed during the phase of eosinophil reaction. 3. The significance of these observations has been discussed in relation to other causes ofeosinophilia and it is suggested that this method of local production of eosinophils may be of experimental importance

1. The importance of recognising osteochondral fractures of the femoral condyle in the adolescent knee joint is emphasised. 2. The mechanism of the formation of the fractures is discussed. Essentially, a powerful rotary and compressive force shears off cartilage and subchondral bone. The absence of lateral condylar lesions in the experimental group lends support to the theory that the patella may cause the fracture by impingement. 3. On the basis of the mechanism a clinical classification of osteochondral fractures of the femoral condyles is presented. 4. Early surgery is recommended. The arguments for removal or replacement of the fragment are discussed

We report the long-term clinical follow-up and survivorship analysis of 40 distal femoral replacements performed between 1964 and 1980 for traumatic, locally aggressive and malignant conditions. Custom-made prostheses with fully-constrained knee joints were used to replace a mean of 42% of the length of the femur. Survivorship analysis showed a cumulative success rate of 80% at eight years, with no subsequent deterioration at 18 years. Clinical assessment revealed 78% excellent or good results. Failure was due to infection in three cases, and in two to fracture of a now-outmoded femoral stem

Thirty-one patients with rheumatoid arthritis were reviewed after Shiers arthroplasty of the knee joint for which the main indication was intractable pain. Seven patients had the operation done to both knees. This review was done to assess the long-term results two to seven years later. All patients were clinically and radiologically assessed, and our results showed that pain and instability recurred within eighteen months. Thus it is likely that a prosthesis which allows rotation, and in which the bearing surfaces are metal on plastic, will replace the Shiers prosthesis

1. Ninety-eight cases of fracture of the upper end of the tibia treated by operative reduction have been reviewed. 2. The true split fractures and the mildly comminuted compression fractures showed the best results. The "mosaic" cases showed the least satisfactory results. 3. Age has scarcely any effect on the end-results and is consequently no contra-indication to operation. 4. Nearly half the patients regained normal or almost normal mobility in the knee joint. 5. In no case did a meniscus left in place cause symptoms indicating internal derangement

1. Because of the controversy over the clinical effects of corticosteroids on joint tissues a series of experiments on the knee joints of rabbits was undertaken. 2. The articular cartilage of the distal femoral epiphyses of normalcontrols has been compared with that of rabbits treated daily either with cortisone or with methyl prednisolone systemically or by intra-articular injections. 3. The changes caused by intravenous papain and their subsequent recovery have been described, and the adverse effect of corticosteroids on recovery has been assessed. 4. The biological mechanisms involved are discussed, and as a result caution is urged in the administration of corticosteroids in the presence of progressive degenerative joint disease

1. Experiments have been carried out in lambs to determine the source of nutrition of the joint cartilage of an immature animal. A wedge of bone with its overlying cartilage was removed from the knee joint and then replaced in its original position, so that the bone was infarcted but the cartilage remained in normal relationship with the joint. 2. In these circumstances degeneration of the cartilage occurred and proliferation ceased until revascularisation of the bone was established. 3. It is therefore concluded that growing cartilage derives a significant part of its nutrition from the underlying bone. The possibility that it also receives a contribution from synovial fluid has not been excluded

We reviewed nine patients at a mean period of 11 years (6 to 16) after curettage and cementing of a giant-cell tumour around the knee to determine if there were any long-term adverse effects on the cartilage. Plain radiography, MRI, delayed gadolinium-enhanced MRI of the cartilage and measurement of the serum level of cartilage oligomeric matrix protein were carried out. The functional outcome was evaluated using the Lysholm knee score. Each patient was physically active and had returned to their previous occupation. Most participated in recreational sports or exercise. The mean Lysholm knee score was 92 (83 to 100). Only one patient was found to have cartilage damage adjacent to the cement. This patient had a history of intra-articular fracture and local recurrence, leading to degenerative changes. Interpretation of the data obtained from delayed gadolinium-enhanced MRI of the cartilage was difficult, with variation in the T1 values which did not correlate with the clinical or radiological findings. We did not find it helpful in the early diagnosis of degeneration of cartilage. We also found no obvious correlation between the serum cartilage oligomeric matrix protein level and the radiological and MR findings, function, time after surgery and the age of the patient. In summary, we found no evidence that the long-term presence of cement close to the knee joint was associated with the development of degenerative osteoarthritis

1. The record is presented of an attempt to treat osteochondritis dissecans on idealistic lines. 2. The operative technique to be adopted in the various circumstances likely to be encountered in the knee joint is described. Two cases affecting the talus are recorded. 3. The radiological appearance has become virtually normal in twenty-seven cases (the remaining four are recent); healing has been observed directly in seven cases in which a second operation to remove the means of internal fixation was necessary; and the patients' complaints have been eliminated, but the long term results of treatment are unknown. 4. Suggestions are made for possible developments in the technique of operation

We performed eight osteochondral autologous transplantations from the knee joint to the shoulder. All patients (six men, two women; mean age 43.1 years) were documented prospectively. In each patient the stage of the osteochondral lesion was Outerbridge grade IV with a mean size of the affected area of 150 mm. 2. All patients were assessed by using the Constant score for the shoulder and the Lysholm score for the knee. Standard radiographs, magnetic resonance imaging and second-look arthroscopy were used to assess the presence of glenohumeral osteoarthritis and the integrity of the grafts. After a mean of 32.6 months (8 to 47), the mean Constant score increased significantly. Magnetic resonance imaging revealed good osseointegration of the osteochondral plugs and congruent articular cartilage at the transplantation site in all but one patient. Second-look arthroscopy performed in two cases revealed a macroscopically good integration of the autograft with an intact articular surface. Osteochondral autologous transplantation in the shoulder appears to offer good clinical results for treating full-thickness osteochondral lesions of the glenohumeral joint. However, our study suggests that the development of osteoarthritis and the progression of pre-existing osteoarthritic changes cannot be altered by this technique

A 14-year-old girl with a congenitally deformed and shortened right leg and foot is described. The patient could not bear weight on the deformed limb and had to hop on the left leg. The deformed foot faced backwards and had nine toes. The right leg was shorter than the left by 26 centimetres. Radiologically, the lower end of the right femur was ill-developed and there was no knee joint. There were two fibulae and the tibia and the patella were absent. A through-knee disarticulation was done and a prosthesis fitted later. The amputated leg and foot were dissected. Many of the muscles in the leg and foot were duplicated. There were two calcanei, one talus, one navicular, two cuboids and four cuneiforms. Ther were nine metatarsals, and all the toes had three phalanges except for one which had two

This is a preliminary report of the results of knee joint replacements using the Liverpool Mark II knee joint system which consists of a bicondylar prosthesis and a set of stereotactic instruments. The prosthesis has been developed from Gunston's concept, and the special instruments ensure its accurate insertion through meniscectomy-type incisions placed on either side of the patella. Particular features of the prosthesis are near-normal articulation, and the simplicity of the operation. Sixty-two knee replacements were implanted in forty-two patients between the spring of 1974 and January 1977. After the operation fifty-six knees were painless and four others produced only slight pain. Full extension was obtained in fifty-eight knees, and none showed a valgus or varus deformity. Collateral laxity was absent in all knees. There were two failures. These early results are most encouraging

1. A sagittal technique for below-knee amputation for ischaemic gangrene based on mediolateral musculo-cutaneous flaps is described, similar to the one independently presented by Tracy (1966). 2. The results with this method are illustrated by the evolution of the below-knee healing rate over six years in 172 patients with ischaemic gangrene. 3. A comparison between sagittal and conventional flap techniques shows a reamputation rate of six out of fifty-eight in the former and sixteen out of forty-one in the latter. 4. The overall relative knee joint preservation during 1971 was 82 per cent, and the frequency of attempted below-knee amputation was 93 per cent. 5. It is concluded that the sagittal technique has several advantages in comparison to the posterior flap technique, and that the potential for healing is on the same high level. 6. A fully controlled comparison between different techniques is proposed

Five vascularised allografts of the knee joint were performed in dogs immunosuppressed with cyclosporin A and azathioprine. Three survived with normal function for 3 to 4 months after operation. One of the unsuccessful grafts had a failed vascular anastomosis, the other an inadequate blood level of cyclosporin A. All three successful grafts healed well. In two, bone scans, radiographs and biopsies were indistinguishable from successful autografts; in the third the blood supply to the graft failed despite patent anastomoses but the graft healed well with good function. All three grafts were rejected within 2 to 3 weeks of withdrawal of cyclosporin A and azathioprine. In non-immunosuppressed dogs, allografts of the knee, both vascularised and non-vascularised, were rejected within a few days of operation. In two non-vascularised allografts, administration of cyclosporin and azathioprine had no apparent effect on the rate of rejection of the graft

Eighty-three Waildius arthroplasties, performed by one surgeon as a salvage operation on the knee joint between 1966 and 1972, were independently reviewed. The fifty-seven living patients with sixty-seven arthroplasties were interviewed and examined and the clinical records of the deceased patients were inspected. Sixty-seven arthroplasties (81 per cent) were successful and sixteen failed (19 per cent). Acrylic cement was used to secure the prosthesis on eight occasions only. There were two primary infections (24 per cent) and two delayed (24 per cent). Major loosening occurred in three arthroplasties (36 per cent). Minor loosening was compatible with a good result. Arthrodesis was successful on the two occasions on which it became necessary to remove the implant. There were no disasters. On the basis of these results it is considered that the Walidius arthroplasty can justifiably be offered as an alternative to primary arthrodesis of the knee

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.

1. The semilunar cartilages are part of the rotator mechanism of the knee joint. 2. Movement of the weight-bearing knee comprises synchronous lateral rotation of the tibia with extension and medial rotation of the tibia with flexion. 3. When this synchrony is disturbed, injuries to the semilunar cartilages result. 4. Damage to the anterior two-thirds of the medial cartilage blocks lateral rotation of the tibia, with consequent physical signs that are pathognomonic of the retracted and the bowstring cartilage, which are the most common types of injury. 5. Each type of cartilage injury produces its own pattern of erosion of articular cartilage and its own sequence of symptoms as so-called arthritis develops. 6. The sequence of symptoms may be halted and often reversed by removal of the torn cartilage. Operation is warranted in most cases however long the history and whatever the age of the patient. 7. The development of medial retropatellar arthritis is explained. The symptoms are often relieved by removal of the medial semilunar cartilage and adequate post-operative rehabilitation

1. The results of viscosity measurements on a number of normal, traumatic and osteoarthritic synovial fluids from human knee joints are described and discussed. 2. A decrease of the viscosity of normal synovial fluid with age has been found. 3. The decrease of the viscosity with age and in the pathological groups is analysed and its relation to the viscous anomaly is considered (Fig. 6). 4. The question whether dilution or depolymerisation is the important factor in decrease of viscosity in these groups, and the value of viscosity measurements as a whole, are discussed. 5. Measurements of pH have been made on the same groups of synovial fluids and on the blood of patients in these groups. 6. The mean values for blood and synovial fluid differ significantly, and the pH of the synovial fluid of adolescents is significantly higher than at other ages. 7. There is no significant difference between the traumatic and osteoarthritic groups, but both are significantly less than the normal. 8. In both fluids the peak frequency in all three groups is the same, that for blood being 7·3 to 7·5 and that for synovial fluid being 7·5 to 7·7 (Fig. 7)

Estimates of knee joint loadings were calculated for 12 normal subjects from kinematic and kinetic measures obtained during both level and downhill walking. The maximum tibiofemoral compressive force reached an average load of 3.9 times body-weight (BW) for level walking and 8 times BW for downhill walking, in each instance during the early stance phase. Muscle forces contributed 80% of the maximum bone-on-bone force during downhill walking and 70% during level walking whereas the ground reaction forces contributed only 20% and 30% respectively. Most total knee designs provide a tibiofemoral contact area of 100 to 300 mm. 2. The yield point of these polyethylene inlays will therefore be exceeded with each step during downhill walking. Future evaluation of total knee designs should be based on a tibiofemoral joint load of 3.5 times BW at 20° knee flexion, 8 times BW at 40° and 6 times BW at 60°

Objectives

Bone void fillers are increasingly being used for dead space management in arthroplasty revision surgery. The aim of this study was to investigate the influence of calcium sulphate bone void filler (CS-BVF) on the damage and wear of total knee arthroplasty using experimental wear simulation.