Reconstruction of metatarsal bone after giant cell tumor resection with no vascularized fibular graft in a pediatric patient: Case report and review of literature.

The Giant Cell tumor (GCT) is a benign, locally aggressive lesion that cause bone destruction and shows a malignant potential. It is a relatively common skeletal tumor that is therefore typically seen in young adults. Few cases are described in literature of GCT in the immature skeleton, and the metatarsal is an unusual location for a primary bone GCT, especially in pediatric age. Therefore, there are very few data reported regarding the management protocol of GCT in metatarsal bones. We report a case about the use of no vascularized fibular graft for an original Y-shaped reconstruction of the metatarsal bone after Giant Cell Tumor resection in a 9 years-old patient, and performed a literature review about metatarsal bone reconstruction in skeletally immature patient.

Osgood Schlatter lesion: histologic features of slipped anterior tibial tubercle.

No study reports the histological features of the various zone of the anterior tubercle of the tibia in the different stages of the Osgood-Schlatter (O-S) lesion. For this reason we carried on an histological study. Specimens were taken from 13 patients with O-S lesion prior to surgery. In 4 cases in the apophyseal stage lesions were present in an altered fibrocartilage anterior to the ossification centre. In 9 cases in the epiphyseal stage varying degrees of reparative tissues were observed in the bed of the fragment of the secondary ossification centre. In 3 of them a zone of lesion was observed within the fibrocartilage anterior to the ossification centre. These results suggest that the slippage of the patellar tendon insertion may be progressive and caused by pathological fibrocartilage.

Segond fracture with anterior cruciate ligament tear in an adolescent.

The authors report a case of acute knee injury in a 14-year-old teenager. The X-ray showed a so-called Segond's fracture: a small avulsed bone fragment, elliptical in shape, lying immediately below the external tibial plateau, a few millimeters from the lateral tibial cortex. The fracture site was in the portion of the tibial condyle which is linked to the middle third of the lateral capsule by meniscal tibial fibers. Clinical examination under anesthesia and subsequent arthroscopy revealed a total intrasubstance ACL (anterior cruciate ligament) tear close to the proximal insertion. The authors confirm Segond's report of a possible association of this avulsion fracture with ACL injuries, even in adolescence.

Role of water content in dielectric properties and delayed luminescence of bovine Achilles' tendon.

In order to investigate the role of water network in collagen structure, measurement of dielectric permittivity was performed on bovine Achilles' tendon as a function of water content. The data show a sudden decrease of the permittivity at each measured frequency value when the tendon humidity decreases. A similar behaviour is shown by the total number of photons emitted in delayed luminescence (DL) experiments. The comparison of the two results is in agreement with the hypothesis that DL is connected to the excitation and subsequent decay of collective electronic states, whose properties depend on the organized structure of the system.

Slipped capital femoral epiphysis in skeletally immature patients.

Fixation by a single screw is considered the current treatment of choice for a slipped capital femoral epiphysis. This approach promotes premature physeal closure. The use of a modified, standard, single, cannulated screw designed to maintain epiphyseal fixation without causing premature closure of the physis was reviewed in ten patients. The nine boys and one girl aged between 10.6 and 12.6 years with unilateral slipped capital femoral epiphysis (SCFE), were markedly skeletally immature (Tanner stage I, bone age 10 to 12.6 years). Clinical and radiological review at a mean follow-up of 44.3 months (36 to 76) showed no difference in the time to physeal closure between the involved and uninvolved side. Measurement of epiphyseal and physeal development showed continued growth and remodelling in all patients. Use of this device provided epiphyseal stability and maintained the capacity for physeal recovery and growth following treatment for both unstable and stable slipped capital femoral epiphysis.

Fetal chondral homografts in the repair of articular cartilage defects.

Lesions of the articular cartilage were bilaterally induced in the patella and the femoral condyle of adult NZW rabbits. A fresh fetal chondral homograft was implanted in one side, the untreated side serving as control. Fetal chondral tissue appeared to survive when implanted at the site of articular injury in adult animals, with no histological evidence of cell-mediated immune response. Fetal chondroblasts showed some signs of maturation and induced endochondral ossification at the base of the graft, with sound anchoring of the graft to the host tissue. In most cases, the homograft fused directly with the adjacent articular cartilage restoring the continuing of the articular surface. However, at implantation the graft could not be easily kept in place, and therefore some grafts had poor mechanical stability. Condylar grafts were incorporated better than patellar grafts. The healing process seemed to be related to the mechanical stability of the graft and to the anatomical site of injury.

The effect of intra-articular ACL reconstruction on the growth plates of rabbits.

We performed intra-articular reconstruction of the anterior cruciate ligament (ACL) with the semitendinosus tendon placed in 2 mm diameter tunnels in 21 skeletally immature rabbits. The operation caused 11% damage to the physis of the femur on the frontal plane and 3% of its cross-sectional area but no alteration of growth or axial deviation of the bone resulted. In the tibia, the operation caused 12% damage to the physis in the frontal plane and 4% of the cross-sectional area. Two tibiae developed valgus deformities and one was shortened. Histological examination showed no areas of epiphysiodesis. There was no abnormality of growth-plate thickness in the two cases of tibia valga. Osseous metaplasia in the grafted tendons did not occur. The results suggest the need for careful evaluation of the percentage of damage to the growth plate before using intra-articular methods for reconstruction of the anterior cruciate ligament in adolescents.

Ultrastructural analysis of the adaptation of articular cartilage to mechanical stimulation.

Ultrastructural analysis was conducted on samples of articular cartilage taken from both load-bearing and non-load-bearing areas with the aim of evaluating the morphologic adaptation of the articular cartilage to mechanical stimulation and identifying the mechanisms of interaction of the chondrocyte and the matrix. Through this analysis we were able to better define the adaptation process of the cartilage as well as the modalities of mechanical stress transmission. We believe that the complex formed by the chondrocyte, the pericellular matrix, and the pericellular capsule constitutes the biomechanical unit of the articular cartilage which serves as the sensor and transducer of mechanical stress. The arrangement of the collagen fibers and the proteoglycans which make up the pericellular capsule and membrane around the chondrocyte can be compared, from a mechanical standpoint, to a dynamic structure constructed in order to absorb the load stresses and protect the internal environment. From a biological standpoint, these are comparable to an extracellular-scaffold constructed with the aim of mediating the interaction between the chondrocyte and the territorial and inter-territorial compartments.

Slipped capital femoral epiphysis: comparison of a roentgenographic method and computed tomography in determining slip severity.

Various conventional roentgenographic methods have been proposed to determine the severity of chronic slipped capital femoral epiphysis (SCFE) on the sagittal plane, with some maintaining that computed tomography (CT) is more accurate and reproduces better than roentgenography. We used a modified Dunlap's technique and angular measurement to determine slip severity. Three orthopaedists obtained data from roentgenograms and CT of 20 hips with chronic SCFE. Statistical analysis showed concordance between our method and the measurements and reproducibility produced with CT. The results suggest that our method is as effective as and less expensive than CT.

[Metaphyseal and diaphyseal fractures of the femur resulting in growth inequality in children under 3 years of age]. / L'esito in dismetria delle fratture metafisarie e diafisarie del femore in bambini fino ai 3 anni di età.

The authors clinically and radiographically review 42 of 53 children between the ages of 5 months and 3 years treated by closed means from 1983 to 1987 for femoral fracture (average follow-up, 4 years). Evaluation of a large number of patients in this particular age group offers several advantages: a) it regards a phase of evolution in which the modalities of growth do not affect in any significant way the metabolic balance of the growth plate chondrocyte, as occurs in periods of rapid growth. This makes the sample group statistically homogeneous; b) it eliminates the age variable in the search for the factors which may contribute to limb-length discrepancy. The importance of the following factors was statistically analyzed: location, type, and initial displacement of the fracture, accuracy of reduction, and characteristics of the traumatic event. There was a significant correlation between a large degree of limb lengthening and further reduction or corrective procedures under general anesthesia. Overlapping reduction and limb shortening were also closely related. A highly significant correlation was also found between limb lengthening exceeding 15 mm. (range, 15-22 mm.) and the time of day at which the trauma occurred (9-10 pm). The results of treatment suggest the need for a reevaluation, using recently gained knowledge, of Lacroix's theory of the pathogenesis of this disorder as well as the need to examine more thoroughly, with further clinical and experimental studies, the hormonal changes following the trauma.

Morphological changes in growth-plate cartilage in osteogenesis imperfecta.

We obtained specimens of growth-plate cartilage from four patients with osteogenesis imperfecta. Light microscopy showed structural changes in the tissue and morphological changes in chondrocytes and matrix, particularly in the hypertrophic zone. There were changes in the process of calcification in the primary mineralisation zone of the cartilage. We also found histochemical changes in the matrix glycosaminoglycans (GAGs) in the zones where physiological mineralisation was disturbed and where the trabeculae were interrupted and poorly mineralised. In addition to the known molecular defects in collagen, changes in GAGs and non-collagenous proteins are important factors in the pathogenesis of the disease.