Endoscopic treatment of the carpal tunnel syndrome: review of the recent literature.

The carpal tunnel syndrome is a common pathology, recognized since one and half century. Its surgical treatment, median nerve neurolysis, has only been popularized 30 years ago. Despite improvement of the surgical technique, two main problems remain unsolved: lack of grip strength and "pillar" pain, which can last several weeks after surgery. Endoscopy, in a same way as knee meniscectomy or cholecystectomy, has contributed to minimize drawbacks of conventional surgery. Ten years of experience have improved the material and the technique, the most recent series reporting very low complication rates. In experimented hands, and with correct indications, endoscopic treatment of carpal tunnel syndrome offers a clinical benefit for the patient and an economical one for the Society.

Split free flap and monofixator distraction osteogenesis for leg reconstruction.

The use of a split muscle flap widens the indications of unilateral external fixation in the treatment of type IIIB open tibial fractures with large bone defects. The same frame can be used for early stabilization and for secondary distraction lengthening procedures. The use of a split flap allows an easy, safe, and painless pin migration. The combination of these techniques represents a very safe solution, especially for patients in poor general and vascular condition.

Prenatal development of the human pelvis and acetabulum.

The prenatal development of the human pelvic bone and acetabulum has been studied by means of classical histology and microradiography. The embryonic phase leads to a fully developed hip within 8 weeks of gestation. The fetal period is a growth phase, including the following main features: endochondral ossification of the ilium from the ninth week, asymmetrical development of the iliac shaft from the fifteenth week, "chondroid-like" tissue formation above the acetabulum from the twenty-sixth week and haversian bone remodelling from the twenty-eighth week. The fetal development of the pelvis and acetabulum seems to be highly related to mechanical stimuli, the most important being the gluteal muscular activity and the simultaneous pressure of the femoral head.

Long-term outcome of neurovascular palmar advancement flaps for distal thumb injuries.

Thirteen neurovascular palmar flaps for thumb tip coverage were reviewed: six O'Brien and seven Moberg flaps with a mean follow-up of 81 months. Both techniques were found to be safe and effective in preserving pulp sensibility, with a mean 2PD of 5 mm and a Semmes-Weinstein identical to the contralateral side in nine cases. The interphalangeal joint regained a normal range of motion, and did not seem to be affected by the perioperative flexion. The main residual complaints were persistent cold intolerance (present in all cases and severe in three), pulp instability (present in six and severe in two), and nail deformity. This last problem was more related to the injury. Despite these drawbacks, O'Brien and Moberg flaps remain the first choice for coverage of 1-2 cm pulp defects of the thumb.

Conservative versus operative treatment for Kienböck's disease. A retrospective study.

In this retrospective study on Kienböck's disease, a comparison was made between 21 cases operated on by various techniques and 22 cases treated conservatively, with a mean follow-up of 65 months. Operative management of the disease did not show any superiority over conservative treatment. Moreover, surgery was responsible for a loss of mobility of 24%, and for a change in social activities in about a quarter of the patients, while grip strength was only slightly improved. Surgical indications for Kienböck's disease should be carefully considered, keeping in mind their side-effects, and the relative benignity in some cases of the natural course of the disease.

Injury to the brachial plexus by a fragment of bone after fracture of the clavicle.

Clavicular fractures are occasionally responsible for lesions of the brachial plexus. The symptoms are usually delayed and due to compression by hypertrophic callus, nonunion or a subclavian pseudoaneurysm. We describe a patient in whom a displaced bone fragment was pressing on the retroclavicular part of the brachial plexus, leading to early symptoms of a lesion of the posterior cord. Internal fixation of the clavicle and external neurolysis of the brachial plexus gave an almost full recovery.

Side-effects of rinsing fluids on the rat femoral artery. A histological and electron microscopic study.

Rinsing rat femoral arteries with various fluids in experimental conditions similar to those in clinical practice was found to have deleterious effects on the intimal and medial layers of the vessels. No statistically significant difference was found between the effects of Ringer's lactate and normal saline. Heparinized saline produced significantly less damage to the medial layer and less platelet cell deposition. Lignocaine 2% was found to be extremely damaging to the whole vessel wall, and highly thrombogenic. Nevertheless, all the arteries in each group remained patent 4 days after rinsing.

Sciatic nerve regeneration in the rat after frozen muscle grafting. A comparative study using somatosensory evoked potentials.

In an experimental study, somatosensory evoked potentials were used to evaluate sciatic nerve regeneration in the rat after 12 mm-long conventional nerve grafting, vascularized nerve grafting and frozen muscle grafting. This experimental method was found to be technically easy and highly reproducible. No statistical difference was found between the three groups concerning amplitude of the negative electrical wave recorded at the cortex level after distal stimulation. Conduction velocities were found to be significantly higher in both the vascularized nerve group and the frozen muscle group, compared with the conventional nerve grafting group. The frozen muscle grafting technique is valuable as it gives good experimental results, is easy to carry out and causes minimal damage to the donor site.

Aging effect on inductive capacity of human demineralized bone matrix.

Demineralized bone powder (DBP) prepared from human cortical bone was implanted into subcutaneous pouches of athymic Nu/Nu mice for 28 days. The osteoinductive capacity was evaluated by histomorphometry of the induced cartilage and bone, and by alkaline phosphatase activity in the implant. Very small amounts of new bone and cartilage were found at histological analysis, confirming that human DBP is much less osteoinductive than that from other species. Whereas the morphometric data of the implants from the young and aged donors were not significantly different, the alkaline phosphatase activity was significantly lower in the implants from the old donors than from the younger ones. This difference between the morphometric and biochemical results could reflect the fact that the enzymatic activity is already present in the osteoprogenitor cells. At 28 days, the osteoblastic activity in contact with DBP from the aged group is characterized by a decrease in the enzymatic amount which is not yet visible at the tissue level. This tendency to a decrease in the osteoinductive capacity of bone matrix is an additional aspect of the age-related alterations which occur in bone tissue and could be attributed to modifications of different proteins of the bone matrix, including bone morphogenetic protein.

Ossification of the human fetal ilium.

Ossification of the ilium is similar to that of a long bone. It possesses three cartilaginous epiphyses and one cartilaginous process. Moreover, it undergoes peculiar osteoclastic resorption, comparable with that of the cranium bones. Asymmetrical ossification of the ilium, haversian bone remodelling and apposition of chondroid tissue posterosuperiorly to the acetabulum most probably emphasize the importance of mechanical factors in the morphogenesis of the hip bone during fetal life.

Long-term sequelae of pelvis irradiation: histological and microradiographical study of a femoral head.

Despite the lack of radiological signs, a femoral head showed histological and microradiographical features of osteonecrosis, 54 years after massive irradiation of the right hip. Intertrabecular spaces were invaded by connectivo-vascular tissue with focal accumulation of mast cells, and several resorption foci were filled with mononucleated cells. Moreover, all the microradiographs showed peculiar hypercalcified lines, sometimes containing empty osteocytic lacunae, the origin of which is difficult to precise. This study suggests that massive irradiation of weight-bearing epiphyses may be responsible for particularly long-term hypovascularity, osteonecrosis and disturbed bone remodeling.

Localised mastocytosis at the bone and porous coated interface of a knee prosthesis.

A porous coated tibial plateau component, which was not loose, was removed 6 weeks after operation. An absence of bony ingrowth was demonstrated by histological and microradiographic examination. The radiolucent space was filled by young connective tissue and inflammation was indicated by the presence of a few macrophages or foreign body giant cells; there was also an increased number of mast cells near the metallic beads. Such inflammatory cells have not previously been reported around a firmly fixed joint prosthesis, but they have been associated with metallic particles. Since accumulations of mast cells can interfere with the process of bony ingrowth, further studies of removed porous coated prostheses should be made with adequate histological techniques so that the clinical significance of these cells can be better understood.

[The external fixator in unstable fractures of the distal end of the radius. Current literature review]. / Le fixateur externe dans les fractures instables de l'extrémité distale du radius. Revue de la littérature récente.

A recent review of the literature concerns instability of distal radius fractures and their treatment by external fixation. Redisplacement of distal radius fractures most often occurs chronically, and the severity can be predicted by initial deformity, axial shortening and dorsal comminution of the radius. The need for an anatomical reduction of these fractures is emphasized by different clinical and biomechanical studies. For many authors, external fixation provides good to excellent results in more than 75% of cases, both clinically and anatomically. Most of the complications are benign and do not affect long-term results. This study also discusses the different techniques and the best indications for external fixation.

Cancellous bone and mechanical strength of the femoral neck.

Twenty pairs of dried macerated femora were submitted to progressive, physiologically oriented loading. The aim of this work was to determine the role of trabecular bone, the importance of the bone mineral density of the femoral shaft, and the importance of the Singh index in the mechanical strength of the femoral neck. By means of an original technique, the influence of both the principal tensile and secondary compressive trabecular groups on the mechanical strength to bending stress has been demonstrated. The artificial destruction of these trabecular groups is responsible for a loss of strength of more than 50% in varus angulation while it has practically no effect in valgus angulation. On the other hand, the mechanical strength of the femoral neck is better correlated with the bone mineral density of the femoral shaft (r = 0.74) than with the Singh index (r = 0.50) or with age (r = 0.15).