Anatomic basis of minimal anterior extraperitoneal approach to the lumbar spine.

Anterior lumbar spine approaches may be indicated for fusion in degenerative lumbar spine disorders or to fill discal and bone gaps after fracture reduction. We present an anterior extraperitoneal approach applicable to any discal and vertebral levels from T12 to S1. The anatomic study, based on 25 cadavers, highlights retroperitoneal dissection principles for easy kidney and duodenopancreatic mobilisation and direct left anterior access to the entire lumbar spine. We established a precise description of the lumbar veins and the anastomoses between the left renal vein and hemiazygos system, in order to define different topographic and anatomic factors related to safe and easily reproducible approaches for cage or graft implementation. Independent of the level and previous intraperitoneal surgery, lumbar spine access with this approach safeguards the kidney, ureter, spleen, hypogastric plexus and duodenopancreatic system. Regarding operating time, blood-loss and possibilities for freshening and grafting, this technique seems an effective counterbalance to the difficulties and complex technology of endoscopic approaches. The clinical study includes our first 42 cases in traumatic and degenerative lesions. Avoiding the neurologic or hemorrhagic risk inherent in classical posterior lumbar interbody fusion (PLIF) techniques, it can be considered as a reasonable and valid alternative. This technique could be used in the near future for mini invasive discal prosthesis insertion.

Anatomic bases of a new technique of juxta-acetabular osteotomy. Technical principles and performance.

Pelvic osteotomies were developed to increase or restructure the acetabular surface. Periacetabular osteotomies are considered the most difficult from the technical point of view and necessitate sufficient residual cartilaginous surface. Juxta-acetabular osteotomies avoid major disorganization of the pelvic framework and allow easier reorientation of the acetabulum. The authors present a technical variant that preserves the entire posterior column, as in the Ganz osteotomy. The effects on the vascularisation of the periacetabular region are strictly the same and there is no necrosis of the subchondral bone. This osteotomy is easier to perform, because of a single positioning associating two simultaneous approaches. The osteotomies are rectilinear and easy to check peroperatively by fluoroscopy thanks to this positioning. Another valuable aspect of this double approach consists of very easy correction of "automatic" unwanted retroversion due to the lowering of the acetabular roof. This unintended displacement is rarely reported in the literature, despite its anatomic evidence in 3-dimensional CT-scan reconstructions for pre- and peroperative evaluation.

Dynamic anatomy of the acetabulum: an experimental approach and surgical implications.

The deformations and stresses acting on the acetabular rim have not been very precisely documented. The authors present a study based on an experimental simulation of hip loading with anatomic correlations. 122 dissections were performed in order to define the anatomic aspect of the roof (and especially of Byers's "area 17") and the intermediate area between the anterior and posterior acetabular cornua. Ten fresh cadavers were tested on the lines of previous studies on monopodal or bipodal loading. An extensometric study was performed with special attention to the transverse acetabular ligament, supra-acetabular area and obturator foramen. The area 17 of Byers is a transitional zone and the mobility of the posterior cornu is 3 times that of the anterior cornu. Resection of the acetabular ligament modifies the displacement of the posterior cornu under loading but has no influence on deformation of the oburator foramen. The biomechanical behavior of the acetabular roof in the standing position is influenced by the conditions of monopodal or bipodal loading and by femoral rotation, but a tendency to extrusion was constantly noted.

Standard and high resolution magnetic resonance imaging of glomus tumors of toes and fingertips.

BACKGROUND: High-resolution magnetic resonance imaging (MRI) of subungual glomus tumors has been recently reported. OBJECTIVE: Our purpose was to compare high-resolution MRI and standard MRI for the diagnosis of 44 glomus tumors of the toes and fingertips. METHODS: Glomus tumors (11 cases) were first examined by MRI with a commercial surface coil (set 1). Thirty-three other glomus tumors and one tumor from set 1 were then examined with a high-resolution module designed for skin imaging (set 2). RESULTS: All 44 glomus tumors were identified with MRI. The limits of the tumors were detected in 54% of set 1 and 100% of set 2. A capsule was present in most cases, but was incomplete or absent in eight cases. Subtypes of glomus tumors were more easily differentiated in set 2. CONCLUSION: Standard MRI was adequate to detect glomus tumors, but high-resolution MRI assessed tumor characteristics more accurately.

MR imaging of digital mucoid cysts.

PURPOSE: To assess the usefulness of magnetic resonance (MR) imaging in the diagnosis and clarification of the physiopathology of digital mucoid cysts. MATERIALS AND METHODS: Twenty-three patients (14 women, nine men; aged 52-75 years) with mucoid cysts underwent MR imaging at 1.5 T with a local surface gradient coil. The pixel size was 117 microns in one direction. T2 relaxation times were measured. Contrast material was intravenously administered in 15 patients. RESULTS: All mucoid cysts had high signal intensity and sharp borders on T2-weighted images. Intracystic septa were present in nine patients (39%). Most cysts were solitary (n = 13) and/or in the proximal nail fold (n = 16). Satellite cysts were present in five patients. Nineteen patients (83%) had cysts with pedicles that extended to the joint. Osteoarthritis of the distal interphalangeal joint was present in 16 patients (70%). Five patients (22%) had multiple flattened cysts that were usually independent of the joint. In seven patients (30%), MR images showed cysts beneath the nail plate. CONCLUSION: Digital mucoid cysts may be polymorphic. MR imaging is helpful when cysts are in the nail bed.

The lunula: a magnetic resonance imagining approach to the subnail matrix area.

High-resolution sagittal magnetic resonance images depict an oval area in the dermis beneath the nail matrix that gives a particular signal. This study defines the magnetic resonance imaging characteristics of this area and examines its correlation with the lunula. A high-resolution surface gradient coil specially designed for skin imagining was used on a 1.5 T magnetic resonance unit. The subnail matrix (SNM) areas of 12 subjects had a significantly longer T2 relaxation time and a higher enhancement ratio after injection of gadolinium than did the nail bed dermis. The length of the SNM area distal to the free edge of the proximal nail fold was highly correlated with the length of the lunula (R = 0.98) in 30 fingers and 10 toes. The total length of the SNM area was somewhat correlated with the nail thickness (R = 0.86) in 30 fingers. The histology and microvascularization of the subungual tissue in 21 fingers showed that this SNM area had specific features: The area was composed of loose connective tissue without bundles, and the reticular and subdermal vascular networks had large regular meshes in this oval area. The lunula is shown to be linked to a well-defined area in the underlying dermis with a specific histology and microvascularization.

Subungual glomus tumors: evaluation with MR imaging.

PURPOSE: To determine the magnetic resonance (MR) imaging features of subungual glomus tumors. MATERIALS AND METHODS: Thirty-one patients with a clinical suspicion of glomus tumor and 10 control subjects underwent MR imaging at 1.5 T. MR images of normal glomus bodies of a cadaver finger were correlated with histologic slices. With a local surface gradient coil, the pixel size reached 117 microns in one direction. Relaxation times were measured. Gadoterate meglumine was injected in 19 patients. RESULTS: Normal glomus bodies were visualized in the reticular dermis of the nail bed. Twenty-seven of 28 pathologically confirmed glomus tumors were detected with MR imaging. A peripheral capsule was present in most tumors. The nail matrix was compressed in 13 cases. The authors were able to differentiate three subtypes of glomus tumors (vascular, solid, and myxoid) on the basis of relaxation times and enhancement characteristics. Four patients had mucoid cysts or angioma in the nail bed. CONCLUSION: MR imaging can help accurately define the location and limits of glomus tumors before excision.

Ultrasono-anatomy of the ankle ligaments.

The ligaments of the ankle are superficial and easily accessible at ultrasonography. Surprisingly, the reliability of this technique has never been proven. With this goal in mind, ten ankles were subjected to a ultrasono-anatomic comparison. The five principle ligamentous fascicles (three on the lateral side and two on the medial side) measured at ultrasonography and the values verified after dissection. This study shows that the ligaments of the ankle are analyzed with ultrasonography and that the measures done are valid and have a precision of 2 mm for the anterior fascicle and the lateral fascicle of the lateral ligamentous plane Due to its simplicity and its low price, ultrasonography appears to be an important method in evaluating the ligaments and the degree of seriousness of ankle sprains.

[The frondiformis ligament and stabilization of the posterior tarsus]. / Ligament frondiforme et stabilisation du tarse postérieur.

The frondiformis ligament is a part of the retinaculum extensorum of the instep. Actuated by the tendons of the extensor digitorum longus, it takes a direct effect on the talus and the calcaneum, induces the valgus of the tarsus and contributes to the stability of the ankle and the foot.

Partial cervicosternotomy: a useful anterior surgical approach to the cervicothoracic junction.

Access to the cervicothoracic junction, whether by lower anterior cervical or transthoracic approach, is particularly difficult. The authors propose partial cervicosternotomy which allows the T3-T4 disk to be reached satisfactorily in 50% of cases and in the remaining 50% allows direct anterior control of the upper two thirds of T3. The advantage of this approach is that it provides direct access to the cervicothoracic junction without leading at the same time to the reconstruction problems caused by the uni- or bilateral sternoclaviculotomies proposed until now. A detailed anatomical study of the arrangement of the intercostal vessels shows that this strictly median approach presents no risk to the medullary vessels thanks to the abundant anastomoses in this region. However, the use of this method may be limited if the aortic vessels have an anomalous origin. Pre-operative angiography is therefore necessary each time T3 must be reached. This approach has already been successfully used in tumor surgery for excision and reconstruction of lesions involving the cervicothoracic region.

Anterolateral thoracic fascia: an anatomic and surgical entity.

This anatomic study, based on six subjects, is aimed at a better description of the anterolateral thoracic fascia, not previously studied in its entirety. The literature describes a fascia of the pectoralis major m. continuous with that of the serratus anterior m., starting at the lateral border of the pectoralis major or pre-pectoral. The upper limits have never been studied and the lower limits are ill-defined, the aponeurosis of the pectoralis major or the pre-pectoral fascia being continuous with that of the rectus abdominis m. It is shown that this fascia, from a retropectoral origin, extends to the base of the axilla above and is stretched as bridge between the pectoralis major and latissimus dorsi mm. and the muscles of the anterolateral wall of the abdomen. This fascia has some surgical importance as a plane of coverage in the protection of mammary implants. The lack of concordance with classical anatomic accounts, the histology and the vascularisation of this fascia call for complementary studies.

A study of the orientation of the fibers of the flexor carpi radialis tendon: anatomy and clinical applications.

The authors report a series of 41 dissections of the forearm intended to study the orientation of the fibers of the flexor carpi radialis (FCR). This shows that there is a constant torsion of the fibers of the FCR by an average of 180 degrees. Half of this torsion occurs in the forearm and half in the sheath of the FCR at wrist level. Awareness of this torsion is particularly useful surgically when the tendon is employed in ligamentoplasty, particularly after trapeziectomy. Our study of the orientation of the fibers was aimed at the ability to perform subcutaneous splitting of the fibers for use of part of the tendon.

[The posterior interosseous artery. Descriptive anatomy. Possibilities of clinical and orthopedic applications]. / L'artère interosseuse postérieure. Anatomie descriptive. Possibilités d'application clinique en orthopédie.

Study of 25 forearms of fresh cadavers, whose the arteries have been injected with colored latex. The posterior interosseous artery is known for its superficial branches, which allow to autonomise cutaneous dorsal flaps. Its way, along the ulna allows to imagine other possibilities by use of the constant branches of this artery, which supplies the proximal and the distal extremities of the bone. The proximal branch is the posterior recurrent radial artery, which supplies the posterolateral face of the proximal pars of the diaphysis, in touch of the insertions of the supinator muscle, and the lateral edge of the olecranon. The distal arteries shape 2 or 3 fascicles, which disperse on the extremity of the diaphysis and the cervical pars of the ulna. To realize a vascular pedicle with the posterior interosseous artery, two cases can be envisaged: use of the distal ulnar epiphysis and creating of a direct pedicle. use of the proximal ulnar epiphysis and creating of a recurrent pedicle.

[The intermetatarsal transverse ligaments and their connections with the tarsometatarsal articulations]. / Les ligaments transverses intermétatarsiens et leurs relations avec les articulations tarsométatarsiennes.

The authors have performed 20 systematical dissections of the distal part of the foot, conserved in the Toulon's liquor and 3 dissections of fresh cadavers. The last ones have been submitted at different puttings in charge before and after the resection of the intermetatarsal transverse ligament. The intermetatarsal transverse ligament is supple, extensible, but very strong. It constitutes the area of convergence of all the neighbouring fibrous structures and of several tendons of the foot. It connects together the heads of the metatarsus. It renders them jointly liable and its action is reflected above. By its modulating of the convergence of the metatarsus and their necessary associated palmar inclination, by its limitation of their divergence in relation with their dorsal inclination, it modulates and it limits the amplitude of the tarsometatarsal joints. It is helped for that by the little intermetatarsal transverse ligaments, whose the presence has been always confirmed. The metatarsus varus, very frequently associated with the hall valgus, means the escape of the first ray from the effect of the transverse intermetatarsal ligament.

[Extension of the fingers. III. Morphologic and structural study]. / L'extension des doigts. III. Etude morphologique et structurelle.

The volar fascicles of the interosseous muscles possess two separate components: the proximal and glenoidal one, the distal and aponeurotic other. The armature of the dorsal aponeurosis is constituted the deep, the central and the collateral expansions of the extensor digitorum muscles, and the interosseous muscles, whom are added the lumbrical muscles. The deep expansions are constant and are fixed respectively at the basis of the first phalanx. The central and the collateral expansions constitute equally the central and the collateral, then terminal tendons, which are respectively fixed at the basis of the second and at the third phalanx. The unitive structures: dossiere, triangular and retinacular ligaments are intricate with this of the armature and render jointly the whole. All the concerned fascicles have the mechanical and histological characteristics of the tendon.

[Extension of the fingers. IV. Morphologic and structural study]. / L'extension des doigts. IV. Anatomie fonctionnelle.

The putting in tension of the dorsal aponeurosis of the digits induces its retraction and the nearness of its insertions on the basis of the 3 phalanges. It depends on the extensor digitorum, interosseous and lumbrical muscles. The aponeurosis is not a single driving belt, but set off in itself 3 types of reaction: 1) The gliding on the sides of the pyramid, which constitute the proximal epiphyses of the phalanges. It suppresses the central dorsal-ward tensions. 2) The displacement of the axes of insertion and rotation of retinacular ligaments inducing collateral volar-ward tractions. 3) The modifications of the way of the structures of transmission: at one time the lengthening of the way is induced by the interactions of the fibers; at other times a shortening is suppressed by the extension of the close proximal joint. Analysis of the different fibrous and fascicular interactions and translations.

[The carpal synovial sheaths and their vascularization]. / Les gaines séreuses carpiennes et leur vascularisation.

The synovial sheaths of the flexor digitorum of 70 pieces of fresh cadavers have been studied on the whole of their length as far as the basis of the fingers: 20 have been injected with a latex or a physiologic solution, after the ablation of the palmar aponeurosis and of the superficial palmar arch. The arteries of the 50 other pieces have been injected with coloured latex solution from humeral artery. The proximal limit of the superficial sheaths is located 5 centimetres above the radiocarpal articular line and this of the deep sheaths 7 centimetres. In the metacarpal area, the superficialis central sheath presents peritendinous expansions, which realise an uninterrupted connection with each digital sheath. It is the aponeurotic and vascular extrinsic compressions, which simulate the interruption of these expansions. The proximal synovial arteries have a muscular origin. The antibrachial collateral arteries, 3 pairs in number, arise from the radial and the ulnar arteries. The distal synovial arteries come from the palmar arches and from their branches: superficial branches for the superficial sheaths and deep branches for the deep sheaths. There is many anastomoses between the different synovial arteries. Two are particularly developed and connect the proximal arteries to the palmar arches: the superficial longitudinal anastomotic artery; which runs close along the medial edge of the median nerve; the deep longitudinal anastomotic artery, which gives the nutritious branches for the tendons of the flexor digitorum. This disposition allows to create two synovial flaps of gliding and vascular help, centred on the anastomotic longitudinal arteries, pediculated on the volar archs and distal-ward rotated.(ABSTRACT TRUNCATED AT 250 WORDS)

[Finger extension. I. History. State of knowledge]. / L'extension des doigts. I. Historique. Etat des connaissances.

Recapitulation of the principal stages concerning the descriptive and the functional anatomy of the extensor apparatus of the ulnar digits. They can be written in the following frame: The Gálien's theories of the exclusive role of the extensor digitorum muscles prevail during more as a millenium. The indispensable conjoined action of the interosseus muscles through the collateral tendon is demonstrated by Duchene in 1867. The role of antagonistic muscles is clearly showed by Bouvier in 1851 on the level of the metacarpo-phalangeal joints and by Valentin and Tubiana in 1962 on the level of the proximal interphalangeal joints. The role of the oblique retinacular ligament on the extension of the third phalanx is specified in 1956 by Landsmeer.

[Finger extension. II. Materials and methods]. / L'extension des doigts. II. Matériel et méthodes.

The study of the extensor apparatus through different methods concerns 200 fingers, the most of fresh cadavers. The dissection through direct observation or with surgical microscope of the dorsal aponeurosis of 30 fingers has been completed by an histological study of 10 fingers. The mechanic properties of each dorsal aponeurotic structure has been tested by extensometry on 12 fingers. The functional study of the role and of the transmission of the different motor components concerns 128 fingers. It has been completed by experimental sections of each aponeurotic structure concerning 20 fingers.