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A macroscopic and histologic study has been made on the changes during a 2-year period in a free composite graft of synovium subsynovial fat and periosteum taken from the medial femoral condyle and placed on the cartilage denuded patellar groove of the knee joint in skeletally mature sheep. The results have been compared to a control group which had the same surgical management except that the graft was discarded. The study demonstrated that following "take" and revascularization, the composite graft had converted to a single layer of vascular fibroblastic tissue by 6 weeks and over the ensuing year this had been largely replaced by fibrocartilage of variable differentiation. However, over the next year much of this fibrocartilage would appear to have undergone either redifferentiation into disorganized fibrochondroid tissue or developed secondary degenerative changes. By contrast, the control specimens had profound resorption of the bone plate followed by patchy resurfacing with tissue ranging from a very loose fibrous connective tissue to well differentiated fibrocartilage. The latter had gradually increased in amount of over the 2-year period, but secondary degenerative changes had also developed as in the grafted group. Despite some of the drawbacks, particularly the magnitude of the patello-femoral compression force, the technique has now been refined into a reliable animal model for the study of different parameters either in the graft or the graft environment in the hope that a way can be found to increase the life span of the metaplastic cartilage.

The role of articular chondrocytes and matrix degrading enzymes such as collagenase and neutral protease in the pathogenesis of quinolone-induced cartilage degeneration was investigated in immature guinea pigs. Articular cartilage from nalidixic acid (NA) treated guinea pigs was examined for the presence of protease activity or the ex vivo synthesis of collagenase at various times post-treatment. Histologic evaluation of knee joints confirmed the presence of degenerative changes in the matrix, but increased collagenase synthesis or protease activity were not detected. A separate group of animals was used to determine the importance of articular chondrocytes in the lesion generation. These cells were killed by intra-articular injection of the glycolysis inhibitor iodoacetic acid (IA) prior to treatment of the animals with NA. Typical "blister-like" their presence was not required for lesion development. Cartilage exposed to IA only did not exhibit "blister-like" lesions indicating that chondrocyte death and proteoglycan loss in conjunction with frictional forces associated with load-bearing were not sufficient to induce major matrical disruptive changes during the period of this study. These results indicate that articular chondrocytes are not actively involved in inducing the degenerative changes and provide no evidence for involvement of collagenase or neutral protease in the pathogenesis of the lesion.

Data was collected on 300 cadaver knees dissected for the prime purpose of studying chondromalacia of the patella. Simultaneous observations were also made on the state of the meniscus and the articular cartilage in the tibio-femoral joint. The data did not seem to support the oft-repeated statement that the torn meniscus is the primary cause of unicompartmental osteoarthritis. Investigations were also carried out on 69 additional cadaver knees and 100 consecutive unselected arthroscoped knees in which there was damage either to the meniscus or the adjacent joint surfaces. In 60% of the combined series of cadaver and arthroscoped knees, the meniscal changes could not be correlated with the condition of the articular cartilage. In the remaining 40% in which there was coexisting pathology in the meniscus and the articular cartilage, a cause and effect relationship could not be established, but there was no evidence that a torn meniscus posed a significant threat to the articular cartilage.

One reason of the chondromalacia patellae is the functional incongruence due to a patellofemoral dysplasia like for example the so called hunter's hat deformity. As a curative treatment in those cases an osteotomy of the patella may be carried out. This operation shall improve the congruence of the articular surface as well as the stability of the patella. There are experimental studies describing the femoropatellar pressure situation in eight cases with a surgical induced hunter's hat patella after osteotomy. The results represent a significant increase of the opposing surfaces in the medial compartment and a more uniform distribution of the femoropatellar pressure.

The clinical, pathological and physiological features of two patients suffering from tracheobronchopathia osteochondroplastica (TO) are described. Unequivocal evidence of extrapulmonary airways obstruction was not able to be obtained by lung function testing, despite extensive central airway involvement in both patients. TO is a rare condition of which there is only one other clinical report from this country. As the bronchoscopic appearance may closely resemble that of endobronchial neoplasms, TO should be remembered in the differential diagnosis of patients with haemoptysis.

The series consisted of 26 patients operated on in 1972-1978 for chondromalacia patellae. The patients were followed up an average of 4.6 years after the operation. The operation involved one knee in 21 patients, both knees in 5. The primary operation was carried out for lesions of the articular cartilage of the patella alone in 18 cases (in 6 of these a second operation was necessary) and for a biomechanical disturbance of the patellofemoral joint in 13 cases. Degenerative changes of the patellar cartilage were observed at anatomo-pathological examination in 29 of 31 knees. On average, the patients' symptoms were alleviated after the operation, but comparison of different types of operation showed a statistically significant improvement only after operations that modified the biomechanics. The results confirm the view that symptoms originating in the patellofemoral joint often are due to biomechanical disturbances of this joint and the extensor system of the knee, and that the removal of injured cartilage alone is not sufficient.

A medial discoid meniscus with cystic formation was found in a 9-year-old girl. The cyst was located in the anterolateral part of the meniscus, mechanically blocking knee extension. The presenting symptom was knee flexion contracture. Total meniscectomy was followed by full recovery.

Otologic experiences in a large burn center are discussed and the following areas are emphasized. First, the otologic effects of hyperbaric oxygen therapy and the prevention and treatment of barotrauma that is occasionally secondary to this therapy. Second, the diagnosis and treatment as well as the prevention of perichondritis in severely burned ears will be discussed. A total of thirty-five cases of perichondritis will be reviewed. An encouraging aspect of the method of treatment has evolved over the past five years: there has been a minimum of deformity in the healed ear, with no subsequent reconstruction necessary. My experience stresses the importance of otologic supervision and ready consultation in all ear burns, and cooperation with the surgeons in charge of the overall care of the burn patient.

Spinal mobility in chondrodystrophoid and nonchondrodystrophoid animal has been studied radiographically. Movement at the lumbo-sacral articulation is approximately three times greater than at other levels in the lumbar spine. The L7-L6 articulation is the second most mobile level. Movement at other lumbar segments is approximately equal. The range of motion is closely similar for both skeletal types which suggests that this factor alone is not of crucial importance in the aetiology of intervertebral disc disorder in chondrodystrophoid animals.

The investigators have induced defects to the articular surfaces of knee joints in rabbits with the use of a CO2 laser. Subsequent healing of these defects have been studied and are described. This work has demonstrated healing with formation of fibrocartilage and hyaline cartilage in two of eight cases. Further investigation with improved techniques will be undertaken in order to produce effective healing on a more consistent basis. This article also reviews previous investigation related to the healing of cartilage defects.

We assessed patellofemoral joint function by combining the measurement of maximal isometric extensor torque at the knee with clinical and radiological measurements in order to calculate the patellofemoral contact force. Eighteen volunteers established the normal ranges of results and the reliability of the system. Of the 39 patients with a variety of knee problems, 29 had anterior knee pain, and all had a subsequent arthroscopy. Patients with anterior knee pain and lesions in the patellar cartilage had significantly reduced isometric contact forces, but those with normal patellofemoral cartilage had normal contact forces. Our method may be useful in providing an objective assessment of anterior knee pain and a quantitative means of monitoring its treatment.

Cartilage destruction in rheumatoid arthritis may be mediated by enzymes of the synovial fluid and by cells of the proliferating pannus tissue. Neutrophilic granulocytes are usually said to affect the cartilage via the synovial fluid, and their local occurrence in the pannus-cartilage border is denied. However, a morphological study on pannus tissue and cartilage by use of histochemistry and immunfluorescence (leucocytes antielastase) exhibited an accumulation of neutrophilic granulocytes in the immediate vicinity of the cartilage in destruction. This result is in contrast to the observation of most investigators reporting studies of the pannus cartilage junction. Experimental datas of the effect of elastase moreover indicate that this enzyme is capable to penetrate into the cartilage and to degrade proteoglycans. Therefore the results show that the occurrence of neutrophilic granulocytes at the pannus-cartilage border is an important phenomenon for understanding the progressive cartilage destruction and that elastase may be at least one enzyme responsible for the degradation of the cartilage matrix.

Twenty-two patients treated non-operatively for chondromalacia patellae were followed up after an average of 5.7 years in order to evaluate the effect of abnormal patellofemoral biomechanics on the natural history of the symptoms. Clinical and radiological investigation revealed 15 patients with signs of malalignment, femoral trochlear dysplasia or excessive lateral pressure syndrome, 3 patients with marginal signs of malalignment and 4 patients with no demonstrable abnormalities. A statistically significant difference in the evolution of symptoms between the normal and the abnormal group is demonstrated, 14 out of 15 in the latter group having unchanged or worsened symptoms. The stage of chondromalacia change as judged arthrographically at the beginning of the observation period did not influence the clinical outcome.

The existence of a cartilaginous facial structure, the mesethmoid, has been demonstrated in the newborn human infant. This structure is the peri- and post-natal tissue developed from the embryonic cartilaginous nasal capsules. Unrecognized during facial development, the cartilaginous mesethmoid, partly because of its multidirectional growth, is responsible for frontonasomaxillary osteomembranous centrofacial morphogenesis. Practical aspects are discussed, and studies to determine the post-natal structures derived from the mesethmoid are in progress.

Tracheomalacia was created in anesthetized piglets by submucosal resection of 3 to 5 tracheal cartilages. Measurements of airway pressure and flow showed that expiratory airway resistance is maximal at low lung volumes and is significantly increased by creation of the malacic segment. Cervical flexion increases expiratory airway resistance, whereas hyperextension of the neck reduces resistance toward normal. External stenting of the malacic segment reduces expiratory airway resistance, and the combination of external stenting and hyperextension restores airway resistance to normal except at low lung volume. Two patients with secondary tracheomalacia required tracheostomy and could not be decannulated after the indication for the tracheostomy was corrected. Both were successfully decannulated after external stenting of the malacic segment with rib grafts. Postoperative measurements of expiratory pulmonary resistance show a marked decrease from preoperative measurements. External stenting of symptomatic tracheomalacia reduces expiratory airway resistance by supporting and stretching the malacic segment and is preferable to prolonged internal stenting or tracheal resection.

The nonequilibrium or kinetic swelling behavior of normal, fibrillated, and osteoarthritic (OA) (removed from total knee joint replacements) human knee joint cartilage has been measured using our isometric tensile apparatus (ITA). We found that large local variations exist in the manner with which human knee joint cartilage swells, including anisotropic effects, inhomogeneities, and dependence on local biochemical composition and pathological condition. The ITA provides three convenient biomechanical parameters--peak stress (sigma p), stress relaxation (sigma R), and diffusion coefficient (D)--to quantify the kinetics of swelling. We used these parameters to quantify and differentiate the kinetic swelling behavior of normal, fibrillated, and osteoarthritic cartilage, as well as the swelling behavior of cartilage from high and low weight-bearing areas. Also, these kinetic swelling parameters correlated very well, though by varying degrees, with such biochemical measures as collagen/proteoglycan ratio, hexosamine content/wet weight, and hydroxyproline content/dry weight, providing important insight into the mechanisms and processes involved during the course of swelling. Hence, the kinetic swelling behavior of cartilage should be used to provide important information not obtainable from equilibrium swelling studies.

In the period from 1980 to 1981, knee joint radiographs were made in 82 patients following the clinical diagnosis of patellar chondropathy. A total of 119 knee joints with patellar chondropathy and 45 with no specific complaints on the contralateral side, in addition to a control cohort consisting of 28 persons, i.e., 56 knee joints with no complaints, were evaluated. Tangential radiographic images of the patellae enabled us to measure directly the rotation of the patella around the axis perpendicular to its center. It could be established that all healthy patellae underwent medial rotation between 45 and 60 degrees of knee flexion which was maintained up to 90 degrees, whereas the affected knee joints did not rotate.

Studying one hundred cases of simple gonarthrosis we found only one supra trochlear femoral erosion (STFE). Such a lesion was discovered in 14 cases among 150 chondrocalcinosis with arthrosic lesions. The cases involving STFE trend to a commun marked chondro-osteolytic evolution. The caracteristic patella sizes show clearly that STFE is not in relation with en anomaly of patella (patella alta...). The upper osteophyte of the patella presents only a minor importance in the formation of STFE. This STFE formation begins probably with a progressive chondro-osteolysis of patella and trochlea. Then, appears a progressive nipping between the upper point of patella and the supra trochlear femoral bone.

In addition to macrotraumas resulting from single and heavy impact, recurrent microtraumas are probably frequently the cause of cartilage damage. The risk of a microtraumatic cartilage damage exists especially in activities involving a high load frequency. Epidemiological studies and dynamometric measurements in race events support this assumption. Based on experimental investigations it is shown how the different components of the articular system-cartilage, synovial membrane and subchondral bone react to microtraumatic stress. In the elimination of microtraumatically induced joint damage special emphasis should be placed on prophylaxis.

The role of proteases in the stimulation of cells participating in a chronic inflammatory reaction is reviewed. Several neutral proteases stimulate B lymphocytes to produce both specific and unspecific antibodies and such enzymes can replace, at least in vitro, T-helper cells. Proteases might influence macrophages as well, by a MIF-like activity, by increasing spreading in vitro or by liberating from C3 the C3b component which has an activating effect on these cells. Endocytosis of protease - alpha-2 macroglobulin complexes by macrophages induces production of neutral proteases as well. A stimulation of fibroblasts by proteases is possible but not yet clearly proven.

The jumping motion of 15 competitive basketball and volleyball players was tested until exhaustion in a cinematographic study. A stereotyped motion pattern was recognisable. The knee joint shows an evasive movement into a valgus and internal rotation position during the acceleration phase before take-off. Furthermore, the knee shows a brief stabilisation in overextension at heel strike. An imbalance of the muscles which stabilise the pelvis and the lower extremities can be regularly found in these athletes and could be a possible cause for this jump motion. It leads to a shortening of the hip flexors and adductors and of the knee extensors with the final evasive action of the knee joint. Though the anatomical condition of the joint is not directly observed, such a motion pattern must be the cause of additional shear forces and peak loads in the area of the patellofemoral joint and of the apex patellae. Clinical experience shows that an active correction of the evasive motion can be achieved by systematic physiotherapy. It ensures muscular balance of the pelvic region and lower extremities and thus lasting good results.

The authors adopted four parameters in a study of 100 normal subjects and fifty patients affected by "chondromalacia" or by recurrent subluxation of the patella. These were: the quadriceps angle, the ratio between the length of the patellar tendon and the length of the patella, the femoral sulcus angle, and the congruence angle between the femur and patella. These parameters showed a statistically significant increase in the pathological group, thereby demonstrating that the majority of cases of "chondromalacia" of the patella and those of recurrent subluxation constitute two entities forming part of the same disease, the basis of which is malalignment and malposition of the patella.

Based on statistical analysis of 97 chronic low back patients, a pelvic list model has been proposed explaining the correlation between leg length discrepancies (LLD) and sciatica. This model suggests that asymmetrical pronation patterns (one pedal arch dropping more than the contralateral pedal arch) initiates a forward downward rotation within the sacroiliac joint. Entrapment of the sciatic nerve between the piriformis muscle and sacrospinous ligament occurs. Clinically, paresis is observed: numbness, weakness and eventually paralysis of the affected limb. Based on this work, the authors have comprised a classification dividing LLD into two main categories: functional and anatomical. Functional LLD have been subdivided into two types of lists: static and dynamic. Treatment based on a combination of chiropractic and podiatric therapy is presented with a 6-month follow-up. Analysis of the success in this tandem approach is very promising. Concurrently, a chondromalacia model is proposed explaining the pathomechanical events associated with oblique tracking patellar syndrome. The authors suggest that excessive pronation is the causative factor directing asynchronous rotation between the shank and femur. This forces the patella out of its normal tracking groove, which, in turn, generates erosion between the inferior margin of the patella and femoral epicondyles.

The classical X-Ray exploration of the patellar instability is done through incidences performed with knees in a 30 degrees flexion and a 0 degrees rotation. To this basic investigation the authors propose to add original, more physiological incidences performed with knees in external rotation. Because of their extreme sensitiveness, these incidences with a 30 degrees external rotation allow a more accurate diagnosis of the patellar instability (and thereby a better breaking up of the still too nebulous chapter of patellar chrondropathies) and a more critical checking of the surgical centering of the patella. Technically easy to perform they should enter into the usual practice of X-Ray exploration of any mechanical knee.

Some chondromalacia are caused by an hyperpressure on the lateral articular facet of the patella. The authors describe the clinical signs and the radiological findings in this condition. It is due to a retraction of the lateral patellar ligament. They have operated on 133 cases and reviewed 115 knees. After a simple section of the lateral patellar ligament, results were satisfactory in 80 percent of the cases. Biopsies of the malacic cartilage were performed and pathological changes were described.

Seventy patellectomies have been performed using an original technique which aims to replace the site of the patella by two cross bands of fibrous tissue derived from the lateral and medial ligaments. This technique preserves the continuity of the extensor mechanism and it allows early mobilisation with shortening of post-operative rehabilitation time. It causes the tendon to thicken, improves cosmesis and maintains the force of the quadriceps, the tendon being kept forward by conservation of the infra-patellar fat pad. The results have been studied in 41 cases of patellar chondropathy, since the results are usually worse in this type of lesion especially in younger patients whose activity is greater. Pain was abolished in 28 cases. The range of movement and quadriceps power was good in all cases but two. In the absence of complications the final result was obtained after 4 months in cases of primary patellectomy. Failures were related to 9 early and 5 late complications. The results were better when the patellectomy was primary and were made worse by any previous surgical procedures.

There are many factors involved in the aetiology of chondromalacia of the patella. If possible, the appropriate operative procedure should be chosen for each patient, hence attempting to eliminate the cause of softening of the cartilage. Increased pressure over the lateral facet, with or without reduced pressure over the medial facet of the patella, resulting from lateral positioning or tilting of the patella, the Wiberg/Baumgartl-types III and IV, and the "Hunter's Hat" form are important causes. With reduced pressure, the cartilage is inadequately stressed and consequently receives insufficient nourishment. As the medial facet is particularly thick and has little contact with the femoral condyle, nutritional disturbance is almost a normal occurrence. Longitudinal osteotomy of the patella has been found to improve the contact of the medial surface of the patella with the femoral condylar groove. The analgesic effect of this surgical procedure may derive from the resultant reduction in subchondral interstitial pressure, presuming that the pain in chondromalacia patellae, like that of osteoarthritis, is a manifestation of raised intramedullary pressure. To ensure an improvement in patellar tracking the osteotomy is combined with a lateral capsular release.

Patellar tracking patterns were studied in 20 cadaver knees. The predominant pattern (Type 1) found in 17 knees included medial shift and medial tilt of the patella with respect to the tibial tubercle during extension of the knee. The remaining three knees (Type 2) showed a tendency toward lateral shift and tilt. Release of the lateral retinaculum had no effect on patellar tracking in most knees, while release of the medial retinaculum produced abnormal tracking in many Type 1 knees and all Type 2 knees. The "proximal realignment" (medial imbrication-lateral release) procedure increased the tendency of the patella to tilt and shift medially during extension.

Two distinct lesions affect the articular cartilage of the patella. Surface degeneration occurs particularly on the odd facet; it is age dependent, often present in youth and it becomes more frequent with increasing age. It probably does not occasion patello-femoral pain in youth, but may predispose to degenerative arthritis in that joint in later years and is regarded as a consequence of habitual disuse. The term "basal degeneration" is used to describe a lesion in which there is a fasciculation of collagen in the middle and deep zones of cartilage without, at first, affecting the surface. It was found astride the ridge separating the medial from the odd facet in twenty-three adolescents who had complained of prolonged patello-femoral pain. They were treated by excision of the disc of affected cartilage, with relief of pain in most cases. The pathogenesis of basal degeneration is related to the functional anatomy of the patella.