The architecture of the diaphyseal bone is closely correlated with the cortical vessel network, whose pattern develops in the course of growth. Various methods have been applied to clarify the three-dimensional anatomy of the cortical canal system, but there is still disagreement about the geometry, blood supply, flux dynamics and factors controlling canal geometry during bone growth and remodeling. A modification of the currently employed dye-injection method was applied to study the vessel network of the whole hemi-shaft of the rabbit femur in mature bones (8-month-old rabbits) and growing bones (1.5-month-old rabbits). The cortical vascular tree of the hemi-shaft of the femur was injected with black China ink and observed in full-thickness specimens of the cortex. The same specimens were then processed for histology. A comparative study of the middle diaphysis (mid-shaft) with the distal extremity (distal shaft) was performed in both young and old rabbit femurs. The longitudinally oriented pattern of the vessel network was seen to develop in the diaphysis of mature femurs, while at the extremity of the shaft of the same specimen the network showed a reticular organization without a dominant polarization. The vessels were significantly higher in the mid-shaft than in the distal shaft of the old femurs ( P < 0.0001), as was their diameter ( P < 0.05). In the group of young rabbits at mid-shaft level the longitudinally oriented pattern of the vessel network was not yet completely developed, without their being significant differences in length and diameter between the mid-shaft and distal shaft. The differentiation of the mid-shaft from the distal shaft was confirmed histologically by the presence, in the latter, of longitudinal calcified cartilage septa between osteons. This pattern of structural organization and development of the intracortical vascular network has not been previously reported. The cells primarily involved in polarization of the remodeling process were the osteoclasts at the top of the cutting cones advancing from the proximal and distal metaphyses toward the midshaft. This suggests, first, a relationship with the longitudinally oriented structures already present in the cortex near the metaphysis (the calcified cartilage septa) and then with the columns of interosteonic breccia, which were formed as a secondary effect of the longitudinal polarization of the remodeling process. Our observations did not enable us to substantiate the model of two different systems, one of longitudinal vessels (Havers) and the other of connecting transversal vessels (Volkmann), but suggested instead that there is a network whose loops lengthen in the direction of the major bone axis in the course of growth and secondary modeling. The associated morphology supported the view that the type of structural organization of the tubular bone cortex is primarily determined by an inherited constitutional factor rather than by mechanical strains.
The vascular anatomy of the cortical bone and the canal system are highly correlated, and the former has an important bearing on shape and microscopic lamellar structure, as it is established in the progression of the remodelling process. The classical description of a longitudinal system of canals (Havers') connected by the transversal Volkmann's canals is the generally acknowledged model of the structural organization of the cortex. However, it is remarkably difficult to study the circulation inside the compact bone in detail owing to its hard, calcified matrix, and the methods thus far applied have represented either the bone morphology and the architecture of the canal system or the injected vessel network. In the present study, the intracortical vessel network was injected with black China ink and evidenced by transillumination of full-thickness, decalcified hemicortices. By making use of the depth of field of the microscope objective, the three-dimensional architecture of the network was highlighted and the morphometry of vessel size measurements and a classification of the network nodes according to the number of arms was made possible. These observations were integrated with data obtained by routine histology on decalcified sections relevant to the connections of the intracortical canal system with the outer environment, with regard to the direction of advancement of new canals and with regard to the mode of formation of the system nodes. The formation of the intracortical vessels network involved two processes: the incorporation of the periosteal network and osteonal remodelling, the latter occurring through the advancement of cutting cones followed by their own vascular loop and by concentric lamellar apposition. The two systems could be distinguished by the diameter of the vessels (the former were significantly larger) and by the network architecture (the former convoluted, and the latter longitudinally orientated and straight). Longitudinal vessels could form branches or create connections with the periosteal derived vessels that occasionally meet on the line of their advancement. They were observed entering from either inside the cortex from the metaphyses or from the endosteal surface of the marrow cavity. The combined observations from different methods of study documented a model of intracortical canal and vessel networks formed by two initially independent systems: one derived from the external, periosteal vessels, and one from metaphyseal and marrow vessels. Connections between the two were established with the advancing of cutting cones from the extremities of the diaphysis. Analysis of the system architecture and the modalities of its progressive organization suggested that the direction of advancement of a forming canal does not necessarily correspond to the final blood flow direction of its central vessel.
Background. Shoulder overuse, both occupational and sports-related, is a major cause of shoulder pain with an estimated incidence of 0.9%-2.5% in the general population and a prevalence of 7%-27% in Europe and United States. We report on a young amateur bodybuilder presenting with a complex shoulder overuse lesion. A posterior labrum periosteal sleeve avulsion (POLPSA) with a chondral lesion of the posterior glenoid cavity and a SLAP lesion was diagnosed. Case presentation. A 33-year-old male construction worker complained of 9 months worsening right shoulder pain. He was an amateur body builder who would bench press heavy weights (up to 170 kg). A magnetic resonance arthrogram showed a posterior labrum sleeve avulsion, a stress chondral fracture of the posterior glenoid cavity and a SLAP lesion. Arthroscopic repair of the bicipital anchor, posterior labrum fixation and removal of the chondral fragment, proved successful and allowed the patient to return to his previous sports activity. Conclusions. Bench press creates major forces along the anteroposter axis of the upper limbs, pushing the humeral head posteriorly and increasing joint reaction force on the posterior glenoid quadrant considerably as the scapula is locked resting on the bench. This may result in a tendency for the humeral head to subluxate posteriorly which, aggravated by the high number of repetitions, puts the posterior labrum and capsula under very high stress eventually leading to labrum failure. Arthroscopic repair was shown to restore shoulder function in these athletes.
Background Revision ACL reconstruction is a complex topic with many controversies and not-easy-to-make decisions. The authors’ aim is to provide some feasible advice that can be applied in daily clinical practice with the goal of facilitating the decision-making process and improving the outcomes of patients subjected to revision ACL reconstruction. Methods A national survey with seven questions about the most controversial topics in revision ACL reconstruction was emailed to members of two societies: SIOT and SIAGASCOT. The participants’ answers were collected, the most recent literature was analyzed, and a consensus was created by the authors, according to their long-term surgical experience. Conclusions The decision-making process in revision ACL reconstruction starts with a standardized imaging protocol (weight-bearing radiographs, CT scan, and MRI). One-stage surgery is indicated in almost all cases (exceptions are severe tunnel enlargement and infection), while the choice of graft depends on the previously used graft and the dimensions of the tunnels, with better clinical outcomes obtained for autografts. Additional procedures such as lateral extra-articular tenodesis in high-grade pivot-shift knees, biplanar HTO in the case of severe coronal malalignment, and meniscal suture improve the clinical outcome and should be considered case by case. Level of evidence V (Expert opinion).
The radiographic follow-up of a patient with Proteus syndrome is presented. Review of radiographs obtained at 3 years 10 months, 10 years, and 17 years 8 months indicated that the rate of growth in length of the oversized tubular bones of the hands was similar to that of the normal bones of the same hand. This observation supports the view that the primary lesion occurs in the early embryonic period, when the limb bud mesenchyme cells condense and cartilage differentiates producing oversized cartilage anlages, rather than being a defect of bone cell-mediated apposition and modelling processes of bone. Additional radiographs of the pelvis and spine were obtained at age 4 years 10 months and head CT at 8 years 10 months. This pathogenetic mechanism fits well with the hypothesis of somatic mosaicism, which is at present the most credible explanation for the aetiology of Proteus syndrome. Other skeletal malformations recognized as typical of the syndrome can be interpreted as secondary adaptations to the altered mechanical conditions induced by overgrowth of bones.
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