Variations in thickness of articular cartilage in the human sacroiliac joint

Differences in articular cartilage thickness in the sacroiliac joint were investigated in different regions of the sacral and the iliac articular surfaces in the embalmed cadavers of five males and six females. The mean thickness of the sacral articular cartilage was greater than that of the iliac articular cartilage (P < 0.001) and the sacral articular cartilage of the female was thicker than that of the male (P < 0.02). Differences between thicknesses of the iliac articular cartilage in the male and female and in different regions of the sacral and iliac articular cartilages were found to be not significant.     

Arthroscopic surgery of the metatarsophalangeal first joint

We report five cases of reactive mediastinal spindle cell proliferations associated with anthracosis and anthracosilicosis that simulated a malignant process both on clinical and morphological grounds. Clinically, the lesions formed radiographically evident masses or were infiltrative. Microscopically, a prominent storiform pattern of intertwining spindle cells was found in four cases. This proliferation extended outside of the lymph node capsule in three cases and surrounded nerves in two. Because of this combination of features, the submitted diagnoses included a malignant neoplasm in four cases. The spindle cells were immunoreactive for histiocytic markers and focally contained fine anthracotic pigment. All cases featured nodular hyaline scars and contained polarizable material suggestive of silica, although a history of industrial exposure was obtained in only two cases. No lesion has enlarged or otherwise progressed during follow-up ranging from 6 to 48 months. The differential diagnosis includes a variety of spindle cell neoplasms, including malignant fibrous histiocytoma, follicular dendritic cell tumor, spindle cell melanoma, and Kaposi's sarcoma.     

Long-term outcome of arthroplasty of the first metatarsophalangeal joint

Carboplatin is a widely used cytotoxic agent in numerous solid tumors of children. Since there is a large degree of interpatient variability in the area under the curve of free carboplatin for a given dose of the drug, the current tendency is to adjust the carboplatin dose so as to reach a target area under the curve rather than to determine a carboplatin dose on the basis of the body surface area. A limited-sampling method was developed for estimation of the ultrafilterable carboplatin area under the curve and for adjustment of the carboplatin dose on subsequent treatments. Population parameters were obtained from 16 children (reference group). We used the maximum a posteriori (MAP) Bayesian approach on 15 children with complete carboplatin pharmacokinetic data (test group). Two blood samples were sufficient to obtain reliable prediction of the area under the curve. The best sampling times were: (a) 30 min after the end of the infusion and (b) 5 h after the end of the infusion. On the basis of these data it is possible to prescribe prospectively a target area under the curve for free carboplatin given in a fractionated daily infusion and to adapt the carboplatin dose directly to ultrafilterable carboplatin measurements.     

Pathomechanics of complex dislocations of the first metatarsophalangeal joint

Because only 10 complex dislocations of the first metatarsophalangeal joint have been reported to date, a retrospective review was initiated to study the pathomechanics of 11 new cases (9 patients) and to report on the clinical and functional outcomes. Concomitant ipsilateral injuries were frequent: 6 tarsometatarsal joint partial disruptions and 8 cases with multiple midfoot or forefoot fractures or dislocations occurred. Clinical and radiographic assessments suggested that forefoot hyperextension combined with axial loading of the foot in a heel to toe or toe to heel direction produced all. Six cases required open reductions (5 were compound), and 5 cases were managed by closed methods. Associated tarsometatarsal joint disruptions facilitated closed management. The most common complaints at followup assessment (average, 7 years) were sensitive plantar wounds, partial joint ankylosis, and sesamoid sensitivity. All but 1 patient resumed the same or modified work. The data in this series suggest that most complex dislocations of the first metatarsophalangeal joint probably occur frequently with a concurrent tarsometatarsal joint sprain or disruption, and that the primary mechanism of injury is that of axial loading of the foot causing midfoot hyperflexion and forefoot hyperextension. Contrary to current opinion, not all complex dislocations of the first metatarsophalangeal joint are resistant to closed management.     

Human joint performance and the roughness of articular cartilage

The Doppler technique has been used to evaluate venous reflux in the spermatic cord. Valsalva-induced reflux occurred on the left side in 83% and on the right side in 59% of 118 patients without clinical varicoceles and there was no difference in incidence between fertile and infertile men. The significance of Valsalva-induced reflux should be questioned. Greater importance should be attributed to the spontaneous venous reflux that occurred during quiet respiration in the majority of patients with varicoceles. Seven velocity waveform patterns are described and these are thought to represent increasing degrees of internal spermatic vein reflux and provide a basis on which it is possible to grade varicoceles. The Doppler grades correlated with the size of the varicocele, and with the internal spermatic vein diameter and testosterone concentrations.     

Retrospective analysis of Silastic implant arthroplasty of the first metatarsophalangeal joint

The purpose of this study was to evaluate the outcome of implant arthroplasty according to subjective, biomechanic, and radiographic parameters over a long period of time. Implants in 40 feet (27 patients) were analyzed at an average follow-up time of 8.25 years and a mean patient age of 63. The results were consistent with the subjective findings of previous studies that demonstrated that most patients were satisfied with the procedure. Ninety-six percent of the patients in this study confirmed they would undergo the procedure a second time. The radiographic results did not demonstrate a high incidence of implant fracture as previously reported. This review suggests that implants can be effective when used with patients who are carefully selected according to age, activity level, and diagnosis.     

Closed reduction of a rare type III dislocation of the first metatarsophalangeal joint

OBJECTIVE: To discuss a rare Type III dislocation of the first metatarsophalangeal (MP) joint, without fracture, that used a closed reduction technique for correction. CLINICAL FEATURES: A 43-yr-old man suffered from an acute severe dislocation of his great toe as the result of acute forceful motion applied to the toe as his foot was depressed onto a brake pedal to avoid a motor vehicle accident. Physical examination and X-rays revealed the dislocation, muscle spasm, edema and severely restricted range of motion. INTERVENTION AND OUTCOME: The dislocation was corrected using a closed reduction technique, in this case a chiropractic manipulation. Fourteen months after reduction, the joint was intact, muscle strength was graded +5 normal, ranges of motion were within normal limits and no crepitation was noted. X-rays revealed normal intact joint congruency. The patient experienced full weight bearing, range of motion and function of the joint. CONCLUSION: Although a Type III dislocation of the great toe has only once been cited briefly in the literature, this classification carries a recommended surgical treatment protocol for correction. No literature describes a closed reduction of a Type III dislocation as described in this case report. It is apparent that a closed reduction technique using a chiropractic manipulation may be considered a valid alternative correction technique for Type III dislocations of the great toe.     

Osteoarthritis involving the metatarsophalangeal joints and management of metatarsophalangeal joint pain via injection therapy

We studied the effect of administration of a mixture of alanine and glutamine on the inhibition of liver regeneration caused by alcohol in rats undergoing partial hepatectomy 6 weeks after the start of alcohol administration. DNA synthesis was inhibited 24 hr after partial hepatectomy in rats given alcohol, but treatment with alanine and glutamine partially prevented this inhibition. To identify the mechanism of this effect, polyamine metabolism was studied. Administration of alcohol or alanine plus glutamine had no effect on the activity of ornithine decarboxylase, a rate-limiting enzyme of polyamine metabolism. In the liver, of the three polyamines, only the spermine concentration changed significantly. It decreased during long-term administration of alcohol, and this decrease was prevented by treatment with alanine and glutamine. The level of N(1)-acetylspermidine, the acetylated product of spermidine, was increased by alcohol, and its elevation was significantly less when alanine and glutamine were given. Hepatic spermidine/spermine N(1)-acetyltransferase, the key enzyme of polyamine acetylation, was induced by long-term administration of alcohol, and this induction was suppressed by alanine plus glutamine. The results suggest that treatment with alanine and glutamine can help to prevent the inhibition of liver regeneration caused by alcohol by maintaining the spermine level and suppressing the acetylation of spermidine.     

A novel cartilage protein (CILP) present in the mid-zone of human articular cartilage increases with age

A novel, somewhat basic noncollagenous protein was purified from guanidine hydrochloride extracts of human articular cartilage using cesium chloride density gradient centrifugation, followed by ion-exchange chromatography at pH 5, and gel filtration on two serially coupled columns of Superose 6 and Superdex 200. The protein of 91.5 kDa contains a single polypeptide chain substituted with N-linked oligosaccharides. It appeared unique to cartilage as studied by enzyme-linked immunosorbent assay and immunoblots of various tissue extracts. Its concentration in articular cartilages showed some variability with age being lower in young individuals. It represents a chondrocyte product, since it is synthesized by articular chondrocytes in explant cultures. Interestingly, the distribution of the protein in the articular cartilage provides important information on the nature of chondrocytes at different compartments in the tissue. Thus, chondrocytes in the middle/deeper layers of the tissue in particular, appeared to have produced the protein and deposited it in the interterritorial matrix. The protein was neither seen in the superficial nor in the deepest regions of the articular cartilage. Based on its immunolocalization we have named this protein CILP (cartilage intermediate layer protein).     

Delayed formation of proteoglycan aggregate structures in human articular cartilage disease states

Proteoglycans are major components of many extracellular matrices. In cartilage, they provide reversible resistance to compression and exist as molecules with molecular weights (MWs) of 1-3 x 10(6). There is a central protein core of MWs approximately 2 x 10(5) (refs 1, 2) with specialized subregions, one containing mainly the chondroitin sulphate chains, another most of the keratan sulphate chains, and a third is a largely globular structure interacting specifically with both hyaluronic acid and a link protein to form stable aggregate structures such as those identified in human articular cartilage. In embryonic and tissue culture systems, proteoglycans are isolated as aggregate structures in as little as 5--10 min after synthesis (sulphation) with no nonaggregating precursor detected. However, Heineg?rd and Hascall have characterized the small proportion of nonaggregating proteoglycan present in bovine nasal septum cartilage and found that it contained more peptide than the aggregating proteoglycan. Work by Upholt et al. has suggested that the MW of unprocessed protein core, synthesized by a wheat-germ translating system from chick sternal cartilage mRNA, is approximately 340,000, leaving open the possibility of intermediates. I report here the presence, in some human cartilages, of a proteoglycan population that initially will not aggregate with the hyaluronic acid but subsequently can be chased into aggregate.     

MR imaging of articular cartilage

Recent theoretical models suggest that males may respond to changes in paternity by adjusting their parental effort. Male response will depend on the availability of reliable paternity cues and the relative costs and benefits of parental effort to the male (i.e. its effect on the survival of young and alternative mating opportunities). Males breeding in pairs may be constrained because reductions in male parental effort are unlikely to be compensated for by the female and thus the survival of both related and unrelated young may decrease. In contrast, males breeding in cooperative groups (i.e. with helpers or co-breeders) may not have this constraint if other individuals in the group compensate for reductions in male parental effort. White-browed scrubwrens, Sericornis frontalis, breed in pairs and cooperative groups, typically with one female and two males (alpha and beta). We found that male parental effort was related positively to paternity for beta males, but not for alpha or pair males. Alpha males had paternity in all broods and always fed young. In contrast, beta males often had no paternity and sometimes did not feed young. Time spent near the fertile female was not an accurate predictor of the percentage of young sired in a brood, but it was a good predictor of having sired young in a brood. Our results are consistent with the idea that male parental effort is allocated according to whether or not the male copulated with the female. We suggest that the relationship between male parental effort and paternity may vary among cooperatively breeding species depending on the type and availability of cues to a male's paternity. Copyright 1998 The Association for the Study of Animal Behaviour Copyright 1998 The Association for the Study of Animal Behaviour.     

Tenascin-C and the development of articular cartilage

In comparison to the vast literature on articular cartilage structure and function, relatively little is known about how articular cartilage forms during embryogenesis and is endowed with unique phenotypic properties, most notably the ability to persist and function throughout postnatal life. In this minireview, we summarize recent studies from our laboratory suggesting that the extracellular matrix protein tenascin-C is involved in the genesis and function of articular chondrocytes. These and other data have led us to propose that tenascin-C may be part of in vivo mechanisms whereby articular chondrocytes develop at the epiphysis of long bone models, remain functional throughout postnatal life, and avoid the endochondral ossification process undertaken by the bulk of chondrocytes located in the metaphysis and diaphysis of skeletal models.     

The fate of the articular cartilage in intracapsular fracture of the femoral neck (articular cartilage in femoral neck fracture)

The fate of the articular cartilage of the hip joint with intracapsular neck fracture was studied by histological, histochemical and autoradiographic techniques and by using a polarized microscope and a scanning electron microscope. Cartilage specimens from 93 femoral heads and 7 acetabula were obtained from fractured hips 2 days to 4 1/3 years postfracture and from control hips with various disorders. The cartilage degeneration appeared 2 weeks after fracture and advanced steadily with time. The matrix was covered, invaded and ultimately replaced by the fibrous tissue. Chondrocyte viability, though it was lost from the surface, was recognized in the deep matrix even in the oldest fracture examined. It is concluded that the humoral factor directly caused by the injury as well as the biomechanical impairment, i.e. a loss of physical stress, may play an essential role in the pathogenesis of the degeneration. The possibility of regeneration was discussed.     

Chondromodulin-I expression in rat articular cartilage

The localization and expression of chondromodulin-I (ChM-I), an angiogenesis inhibitor, in the rat articular cartilage during maturation from 2 to 10 weeks of age were examined by immunohistochemistry, Western blot analysis and ribonuclease protection assay, and the results were compared with those in the epiphyseal cartilage. ChM-I was found to be diffusely immunostained in the inter-territorial space of the cartilage matrix from the intermediate to the deep layers at the immature stage. As the articular cartilage matured, the immunoreactivity was localized around the hypertrophic chondrocytes in the deep layer and the immunoreactivity became weak after maturation. In contrast, the ChM-I immunoreactivity was intense in the epiphyseal cartilage at all ages examined. ChM-I was detected by Western blotting as a broad band or occasionally as a cluster of multiple bands (approximately 25 kDa) in both the articular and the epiphyseal cartilage. The intensity of the bands decreased gradually with age in the articular cartilage, but was unchanged in the epiphyseal cartilage at all ages. Ribonuclease protection assay revealed that ChM-I mRNA also decreased gradually with age in the articular cartilage in parallel with the maturation of the articular cartilage, while no decrease in ChM-I mRNA was found in the epiphyseal cartilage. The expression of ChM-I mRNA in the articular cartilage was less than that in the epiphyseal cartilage at all ages. The decrease in amount of ChM-I in the mature articular cartilage suggests that ChM-I plays a more important role in the maintenance of avascularity in the immature articular cartilage than in the mature one. The avascular condition may be preserved by angiogenic inhibitors or mechanisms other than ChM-I in the mature articular cartilage.     

Degenerative joint disease in poultry--differences in composition and morphology of articular cartilage are associated with strain susceptibility

The importance of recovery following pulsed and continuous exposure was determined by measuring the acute toxicity of two organophosphorus (parathion and malathion) and four carbamate (aldicarb, carbaryl, carbofuran and propoxur) insecticides. Two 1-h pulses caused significantly fewer symptoms of intoxication than 2 h of continuous exposure if at least 2 to 6 h in clean water were provided between doses for the four carbamates. Two 1-h pulses were equally toxic as a single 2-h continuous exposure for the two organophosphorus insecticides. Acetylcholinesterase activity in midges given two 1-h pulses of carbaryl separated by 24 h in clean water showed reactivation to control levels between the two exposures. These results contribute to the belief that episodic exposure to insecticides is less toxic if recovery in clean water is provided.     

The structure of the keratan sulphate chains attached to fibromodulin from human articular cartilage

We have previously demonstrated that fibroblasts and invasive human breast carcinoma (HBC) cells specifically activate matrix metalloproteinase-2 (MMP-2) when cultured on 3-dimensional gels of type I collagen but not a range of other substrates. We show here the constitutive expression of membrane-type 1 (MT1)-MMP in both fibroblasts, and invasive HBC cell lines, that have fibroblastic attributes presumably acquired through an epithelial-to-mesenchymal transition (EMT). Treatment with collagen type I increased the steady-state MT1-MMP mRNA levels in these cells but did not induce either MT1-MMP expression or MMP-2 activation in noninvasive breast carcinoma cell lines, which retain epithelial features. Basal MT3-MMP mRNA expression had a pattern similar to that of MT1-MMP but was not up-regulated by collagen. MT4-MMP mRNA was seen in both invasive and noninvasive HBC cell lines and was also not collagen-regulated, and MT2-MMP mRNA was not detected in any of the HBC cell lines tested. These data support a role for MT1-MMP in the collagen-induced MMP-2-activation seen in these cells. In situ hybridization analysis of archival breast cancer specimens revealed a close parallel in expression of both collagen type I and MT1-MMP mRNA in peritumoral fibroblasts, which was correlated with aggressiveness of the lesion. Relatively high levels of expression of both mRNA species were seen in fibroblasts close to invasive tumor nests and, although only focally, in certain areas close to preinvasive tumors. These foci may represent hot spots for local degradation and invasive progression. Collectively, these results implicate MT1-MMP in collagen-stimulated MMP-2 activation and suggest that this mechanism may be employed in vivo by both tumor-associated fibroblasts and EMT-derived carcinoma cells to facilitate increased invasion and/or metastasis.     

Hallux valgus in the elderly: metatarsophalangeal arthrodesis of the first ray

This study compares the dental utilization of United States of America (USA) military recruits with that of their employed civilian cohorts. Military data were collected between February and June 1994 at one recruit in processing site per service, using self-administered questionnaires on a prestratified, systematic, random sample of 2369 Army, Air Force, Navy, and Marine recruits. Women and blacks were oversampled. Civilian data come from the most recent oral health survey of working adults in the USA. Results show that annual dental utilization rates of military recruits equal or are less than those of their employed civilian cohorts. Overall, 38% of recruits have seen a dentist in the past year, while 30% have not seen a dentist in 3 or more years. Such low consumption of dental care suggests that dental utilization habits prior to service entry do not contribute appreciably to the high dental utilization rates seen among active duty US military personnel.