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Afferent activity in the lateral (LAN), medial (MAN), and posterior (PAN) articular nerves supplying the cat knee joint was studied at intermediate positions of the joint that included most of its working range. The discharge was analyzed only while the joint was stationary. The small LAN showed negligible tonic activity at intermediate angles (as determined by gross recording) and was not studied further.
1. One hundred thirty-eight knee joint afferents from posterior articular nerve (PAN), in primates, were recorded in dorsal root filaments. Responses of afferents were studied in relation to both passive manipulations of the knee and active contractions of quadriceps, semimembranosus, and gastrocnemius muscles. 2. When the knee was passively rotated, most neurons discharged only when extreme angular displacements were achieved. Response of neurons responding to passive extensions was linearly related to the torque applied to the knee. With maintained extensions, discharge in extension neurons adapted slowly. Some of the time constants of adaptation were similar to those for simultaneously recorded torque relaxation. 3. Contractions of quadriceps, semimembranosus, or gastrocnemius muscles could activate many neurons in the absence of changes in joint angle. For quadriceps-activated neurons, rather high torques (mean = 2,450 g with cm) were required. 4. The results support the hypothesis that joint afferents function as capsullar stretch receptors, responding to those mechanical events which result in loading of the capsule.
Pressure measurements in the knee joint and gastrocnemio-semimembranosus bursa were performed on patients and autopsy cases. A normally occurring closure mechanism between the joint and the bursa was demonstrated and analysed. Two patients were also found to have a partial valvular mechanism in the form of a hindrance to spontaneous passage of fluid from the bursa to the joint but no hindrance in the other direction.
This work consists of two parts. Part One is a three-dimensional study of the passive motion of the elbow joint and revealed that the elbow joint was not a true hinge joint. Part Two is a three-dimensional quantitative motion analysis which was undertaken to compare shoulder and trunk motion in normal subjects with those with contracted elbows. This analysis revealed that shoulder rotation, shoulder abduction, trunk flexion and trunk rotation compensates for a contracted elbow.
In order to define the deformation of articular cartilage and the joint space under statically loaded knee joints, we studied serial sections in the frontal plane of knee joints which were frozen under the application of a load. Normal articular cartilage surfaces did not make contact even under loads of 100kg or more, leaving always a space between. The compressive deformation of articular cartilage mainly occurred at the central area near to the intercondylar notch or prominence, but the deformation of cartilage in the area covered by menisci was negligible.
Based on the clinical and radiological examinations of 95 patients with unilateral restricted movement of the hip, the deformities of ileosacral joint and symphysis are described. The pathological changes of ileosacral joints and symphysis could be demonstrated in cases with severe contractures of the hip. Low grade contractures under 15 degrees have been tolerated over many years.
Thirty-one cases of plastic knee joint operations were reported. Twenty-one patients were treated with the geomedic knee. The advantage of this joint is that only a small amount of bone must be sacraficed. The range of movement is better than that with a complete knee prosthesis with axis.
Systematic examination of 733 cases of replacement of the hip-joint, operated on with an identical technique and method of post-operative treatment. Frequency and severity of periarticular ossification, their relationship to pre-operative arthrosis and their effect on joint function are described. Development and localization of periarticular ossification, their higher incidence after tearing off of the trochanter, removal of osteophytes and occurrence of hematomata hint at surgical trauma as one of the causes. Preliminary operations on the proximal end of femur did not influence ectopic ossification. Ossification of grade I did not interfere with function, grades II and III limited movement in varying degrees.
A technique of arthrodesis of the ankle joint under television control and with the aid of a special milling-cutter is presented. A bone graft is obtained from the ankle and turned in two planes, so that the joint space becomes vertical. The operation time is shortened to 8--10 min. After two weeks the patient can walk, in a walking-cast, weight-bearing. Bone fusion is obtained in 3--4 months. Thirty-two cases were operated on, and in 30 a painless osseous fusion of the ankle, in a functional position was obtained. The technique is indicated only in cases in which, operatively, the foot can manually be reduced to a functional position.
Arthroscopy and clinical examination was performed on the knee joint of 26 patients with chronic inflammatory joint disease, before and at 6 and 12 months after open synovectomy. Biopsies were examined by histologic and immunohistologic methods. Clinically the patients improved until 6 months after synovectomy, and the improvement was maintained for 5 years. Patients with the best clinical function prior to synovectomy also had the best long term results (p = 0.024). The state of the cartilage was the best predicting variable with a significant prognostic power (p = 0.01). Thus patients with normal cartilage at the time of synovectomy had the best clinical score five years later. The patients with most resynovitis 12 months after surgery did less well at five year clinical follow up (p = 0.032) than those with little or no resynovitis. Absence or low number of IgA-positive plasma cells in the cellular infiltrate at 12 months after surgery correlated with a good clinical score five years after surgery (p = 0.036). This suggests that a high number of IgA-positive plasma cells may be indicative of a more aggressive, destructive disease.
After a short review of the theory of the forces acting in the human hip joint we develope a new model for the calculation of the forces R acting on the head of the supporting femur, of their direction phi and of the maximal pressure of the femoral head. The new concept is the determination of a fixed point A, the attachement of the resultant muscle force M at the pelvis, and the insertion T of this muscle force at the trochanter. After determination of this points in a single standard radiography of the pelvis and hips, the model calculate the resultant force R at the hip joint. The pressure in the articulation is calculated also by the same proceeding. The influence of the choice of the point A is discussed.
An unusual bilateral closed dorsal dislocation of the metatarsophalangeal joints of both great toes is described, and surgical treatment and outcome reported. The importance of postreduction X-rays is emphasized.
Traumatic dislocation of the medial four carpometacarpal joints in a child is an unusual injury. Descriptions of this injury in the literature have been reviewed and a case is presented to illustrate the pertinent anatomy, biomechanical aspects, and details of management. Specifically, the importance of collateral circulation to the hand and an effective technique of pin fixation are described.
The first metacarpo-phalangeal joint is assumed to be exposed to incongruent functional demands, when gripping. They may lead to pre-arthrotic deformity and frequent arthrosis. A new special prosthesis, its insertion and first results are described. It fulfills all functional demands and can be used also for younger patients.
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.
Thickness of synovial lining cell layers, cytological appearance of synovial cells, the grade of fibrosis, the distance between subsynovial blood vessels and synovial surface, possible inflammatory infiltrations etc. have been controlled in synovial preparates of 106 mandibular joints. The age dependent fibrosis of the synovial tissue has been demonstrated.
The composition and lipid profiles of the following tissues of the human knee joint were determined: articular cartilage, meniscus, ligaments, synovial fluid, synovium, intra-articular fat pad and bone marrow. The tissues were obtained from fresh cadavers and from surgical specimens. The lipid profiles of articular cartilage, meniscus and ligaments were similar to reported analyses of other tissues that are also rich in collagen. The lipid profiles for the remaining tissues were more like the profiles found in the fat depots and fatty tissues of the human body. Both the phospholipid and fatty acid patterns of these tissues were similar within statistical deviation. These results suggest that the per cent compositions of fatty acids and the phospholipid family profile ratios have limited range variability in the "normal" tissues of the human knee. On the other hand, the per cent neutral lipid compositions and their individual profiles showed great variations among the different tissue tissues of the knee.
Investigations of the articular mechanics of the tempero-mandibular joint are an important element in gnathology. Graphically recorded movements of the condylus obtained by extra-oral mechanical aids, only give information about the projections of the articulatory pathways. Only roentgencinematography allows a profound study of the articular mechanics. The movements of the condylus can be analysed directly without interference. Studies on condylar pathways evaluated by roentgencinematography from waerers of full dentures who received two sets of dentures which fitted after different jaw relation determinations, confirmed that the movement of the condylus is controlled by neuromuscular mechanisms. The condylar pathway changes after removal of the dentures. The fitting of different dentures in a healthy stomatognatic system had no effect on the course of the pathway. In neuromuscular disorders the fitting of a full denture which can be made corresponding to the functional anatomical concept reflecting a suitable jaw relation determination according to Gerber, allows the articulation pathway to be altered. A therapeutic re-orientation of the pathological reflexes makes the improvement of the discomfort possible.