Christian Fontaine

Variations of pelvic anteversion in the lying and standing positions: analysis of 24 control subjects and implications for CT measurement of position of a prosthetic cup.

The position of the acetabular implant plays a dominant role in the displacement of a total hip prosthesis. CT allows precise measurement of the position of the cup, but the influence of pelvic rotation on this measurement is unknown. The aim of this study was to determine, in a group of healthy subjects, whether a pelvic equilibrium exists specific to each individual, and whether this is constant over time on the one hand and between the standing and lying positions on the other. The study concerned 15 men and 9 women with a mean age of 31 years. Each subject had strictly lateral radiographs of the pelvis, lying and standing, repeated at two different times. Pelvic version was measured in these radiographs. Each individual had a pelvic position constant over time, both in the lying and standing positions, However, there were important variations of the position of the pelvis during passage from the lying to the standing position 22 patients had retroversion of the pelvis by a mean of 7° (2-18°) and 2 others had an anteversion of 3°. These major variations of the pelvic position between the standing and lying positions explain why CT studies made in the lying position do not allow for the anteversion of the cup in the standing position, which is close to the dynamic situation during which displacement may occur. Thus, an excessive anteversion of the cup may be masked when the scan is made in the lying position, since in this position the anteversion of the pelvis leads to retroversion of the cup. The error may reach 20°, so that we recommend that CT measurements made without allowing for the position of the pelvis should be interpreted with caution.

Inter- and intraobserver reproducibility in radiographic diagnosis and classification of femoral trochlear dysplasia

Dejour’s radiographic criteria are commonly used to diagnose and assess femoral trochlear dysplasia in case of patello-femoral instability. The aim of this study was to establish the intra- and interobserver reliability of these radiographic criteria. Sixty-eight lateral knee radiographs were examined independently by 7 observers (2 juniors, 5 seniors) to assess interobserver agreement, and the 2 juniors repeated the observations to test intraobserver agreement. These 68 true lateral views were harvested from clinical records of 64 patients who underwent a trochleoplasty because of patellofemoral instability. To evaluate the agreement on analytic data (morphologic type of trochlea) we used the kappa statistical method, and to evaluate the agreement on numerical data (depth and prominence of the trochlear groove) we used interclass correlation analysis. The “crossing sign” (between the trochear groove and the anterior aspect of both condyles) was reliable since the probability of rating as normal a pathologic trochlea was only 3.1% (0 to 8.8%). In classifying trochlear morphology interobserver agreement was slight (kappa = 0.17) and intraobserver agreement was fair (kappa = 0.3). On the other hand, the measurements of the depth and prominence of the trochlear groove were more reliable since the interclass coefficients between observers were 0.62 and 0.38 respectively. The most frequent interobserver error was related to misdiagnosis of type II. To clarify Dejour’s criteria we propose a diagnosis of type II only when 5 mm or more are measured betweeen the intersections with the medial and lateral femoral condyles. We recommand the use of the prominence of the trochlear groove to evaluate the grade of bony trochlear dysplasia.

Long-term Survivorship of Hip Shelf Arthroplasty and Chiari Osteotomy in Adults

The current authors retrospectively assessed 56 hip shelf arthroplasties (48 patients) with a mean followup of 17 years (range, 15–30 years) and 89 Chiari osteotomies (82 patients) with a mean followup of 13 years (range, 6–25 years) done in adults with painful hip dysplasia. Preoperative joint space narrowing was observed in 32 of 56 shelf arthroplasties and in 67 of 89 Chiari osteotomies. Survival rates, using hip replacement as the end point, were 37′ (20′ to 54′) at 20 years for shelf arthroplasty and 68′ (54′ to 81′) at 18 years for Chiari osteotomy. The severity of preoperative arthrosis was the main factor that impaired the survivorship of shelf arthroplasty and Chiari osteotomy. With arthritic changes without joint space narrowing, the 18-year survival rates were 83′ (69′ to 97′) for shelf arthroplasty and 94′ (89′ to 99′) for Chiari osteotomy. Shelf arthroplasty is best indicated for moderate dysplasia (center edge angle >0°) without severe arthrosis. Chiari osteotomy is best suited for severe dysplasia (center edge angle <0°) especially without or with slight arthrosis. Chiari osteotomy also can be a salvage procedure when marked joint space narrowing is present but only if it is related to severe dysplasia (center edge angle <0°).

DCX-expressing cells in the vicinity of the hypothalamic neurogenic niche: A comparative study between mouse, sheep, and human tissues

Neural stem and precursor cells persist postnatally throughout adulthood and are capable of responding to numerous endogenous and exogenous signals by modifying their proliferation and differentiation. Whereas adult neurogenesis has been extensively studied in the dentate gyrus of the hippocampal formation and in the subventricular zone adjacent to the wall of the lateral ventricles, we and others have recently reported constitutive adult neurogenesis in other brain structures, including the hypothalamus. In this study, we used immunohistochemistry to study the expression of the neuroblast marker doublecortin (DCX), and compared its expression pattern in adult ovine, mouse, and human hypothalamic tissues. Our results indicate that DCX‐positive cells resembling immature and developing neurons occur in a wide range of hypothalamic nuclei in all three species, although with different distribution patterns. In addition, the morphology of DCX‐positive cells varied depending on their location. DCX‐positive cells near the third ventricle had the morphology of very immature neuroblasts, a round shape with no processes, whereas those located deeper in the parenchyma such as in the ventromedial nucleus were fusiform and showed a bipolar morphology. Extending this observation, we showed that among the cohort of immature neurons entering the ventromedial nucleus, some appeared to undergo maturation, as revealed by the partial colocalization of DCX with markers of more mature neurons, e.g., human neuronal protein C and D (HuC/D). This study provides further confirmation of the existence of an adult hypothalamic neurogenic niche and argues for the potential existence of a migratory path within the hypothalamus. J. Comp. Neurol. 522:1966–1985, 2014.

Branching Patterns of the Infraorbital Nerve and Topography within the Infraorbital Space

The infraorbital nerve (ION) is the terminal branch of the maxillary nerve; it supplies the skin and mucous membranes of the middle portion of the face. This nerve is vulnerable to injury during surgical procedures of the middle face. Severe pain and loss of sense are noted in patients whose infraorbital nerve is damaged. In the study presented here, we investigated the branching pattern and topography of the ION, about which little is currently known, by dissecting 43 hemifaces of Korean cadavers. In most cases, the infraorbital artery was located in the middle (73.8%) and superficial to the ION bundle (73.8%) at its exit from the infraorbital canal. The ION produced four main branches, the inferior palpebral, internal nasal, external nasal, and superior labial branches. The superior labial branch was the largest branch of the ION produced the most sub-branches. These sub-branches were divided into the medial and lateral branches depending upon the area that they supplied. We were able to classify four types of branching pattern of the external and internal nasal branch and the medial and lateral sub-branches of the superior labial branch of the ION at the site of their emergence through the infraorbital foramen (types I-IV). Type I, where all four branches are separated occurred the most frequently (42.1%). These findings will help to preserve the ION while performing certain types of maxillofacial surgery, such as removal of a tumor from the upper jaw and fracture of the upper jaw.

Topographic distribution area of the infraorbital nerve

The infraorbital nerve (ION) supplies the skin and mucous membranes of the middle portion of the face. This nerve is vulnerable to injury during surgical procedures of mid-face. Severe pain and loss of sense are noted in patients whose infraorbital nerve is either entirely or partially lost after these surgeries. We investigated the distribution area and topography of the ION, about which little is currently known, by dissecting 43 hemifaces of Korean cadavers. The ION produced four main branches, the inferior palpebral, internal nasal, external nasal, and superior labial branches. The inferior palpebral branch was generally bifurcated, giving off a medial and a lateral branch (58.1%). The internal nasal branch ran superior to the depressor septi muscle, along the ala of the nose. It supplied the skin of the philtrum and gave off a terminal branch that supplied the nasal septum and the vestibule of the nose. The external nasal branch was distributed diversely supplying areas between the root and the ala of the nose. The superior labial branch was the largest branch of the ION produced the most subbranches. These subbranches were divided into the medial and lateral branches depending upon the area that they supplied.

Outcome of Chiari pelvic osteotomy in adults: 90 hips with 2-15 years' follow-up

We studied retrospectively 90 Chiari osteotomies in 83 adults with pain, hip dysplasia and arthrosis. At follow-up after 6 (2-15) years, 35 hips were pain-free, 38 had rare or slight pain, and 17 had moderate or severe pain. The dysplastic acetabulum was corrected in all but 5 cases. There was diminution of arthrosis in 36 hips, no change in 38, and worsening in 16 hips. Functional outcome was best when surgery was performed before the age of 40, and in hips with the greatest degree of dysplasia. However, two thirds of the patients aged over 40 years at surgery had a good result.

An anatomical study of the insertion of the zygomaticus major muscle in humans focused on the muscle arrangement at the corner of the mouth.

Background: The aim of this study was to clarify the arrangement of the zygomaticus major muscle by means of topographic examination, and to evaluate the anatomical variations in the insertion of the zygomaticus major at the perioral region. Methods: After a detailed dissection in the modiolar region, the insertion area of the zygomaticus major was observed in 70 embalmed cadavers. Results: At the perioral region of the dissected specimens, the anatomical aspects of the muscular arrangement and attachment of the zygomaticus major muscle were classified into four categories. In type I, the superficial muscle band of the zygomaticus major is blended and interlaced with the levator anguli oris, whereas the fibers of the deep muscle band blend into the buccinator, passing deeper to the levator anguli oris; this was the situation most commonly encountered (54.3 percent). It was found that the insertion of the zygomaticus major was divided into superficial and deep bands (types I and IV) [42 cases (60 percent)] and into three layers of superficial, middle, and deep fibers (type II) [17 cases (24.3 percent)]. The others were cases where the zygomaticus major was inserted deep into the levator anguli oris as a single muscle band (type III) [11 cases (15.7 percent)]. Conclusion: The arrangement and insertion patterns of the zygomaticus major in this study are expected to provide critical information for surgical planning for the procedure of facial reanimation surgery.

Innervation of the medial epicondylar muscles: an anatomic study in 50 cases

The median nerve is classically distributed to the medial epicondylar muscles by two branches (superior and inferior) for the pronator teres muscle, a common trunk for the flexor carpi radialis and palmaris longus muscles, and a branch for the flexor digitorum superficialis muscle. The 50 dissections were made by two workers on 30 upper limbs of formolized cadavers and 20 limbs from fresh-frozen cadavers. The innervation of the pronator teres m. was classical in only 26% of cases, and the “normal” pattern for the flexor carpi radialis and palmaris longus mm. was found in only 40% of cases. The innervation of the flexor digitorum superficialis m. was the least subject to variations, a single branch being observed in 68% of cases. We found a solitary medio-ulnar anastomosis of Martin-Gruber to the flexor carpi ulnaris muscle. This study confirmed the great variability of the branches of the median nerve at the elbow, and the importance of identifying them in surgical procedures for transposition of the medial epicondyle.

Résection de la rangée proximale des os du carpe: Résultats de 25 cas au recul moyen de 30 mois

Resume La resection de la rangee proximale des os du carpe consiste en une simplification de l’articulation radio-carpienne, et est principalement realisee dans le cadre de collapsus carpien avance. L’emergence de nombreuses alternatives therapeutiques justifie une etude de ses resultats, afin de mieux preciser ses indications au sein des differentes pathologies concernees. Une evaluation clinique et radiologique a ete effectuee chez 25 patients, ayant beneficie de cette intervention entre janvier 1999 et fevrier 2004, au recul moyen de 30 mois. Trois etiologies principales etaient representees : sequelles de fracture du scaphoide (9 cas), sequelles de dissociation scapho-lunaire (9 cas) et maladie de Kienbock (6 cas). Tous les patients ont ete operes par voie d’abord posterieure et ont fait l’objet d’une analyse evaluant le resultat clinique (douleur, force, mobilite), le resultat radiographique (hauteur du carpe, espace radio-capital), l’appreciation personnelle et une eventuelle reprise d’activite professionnelle. Les scores de Cooney et Culp ont ete calcules. L’arc de mobilite moyen en flexion-extension etait de 60° ; la force de la poigne etait mesuree, en moyenne, a 65 % de la valeur du cote oppose. Les douleurs ont ete ameliorees dans 88 % des cas et la note subjective moyenne etait de 15,2. Les scores moyens de Cooney et de Culp etaient respectivement de 58,0 et 67,8. Une perte de hauteur de l’interligne neo-articulaire, ne correspondait pas toujours a un mauvais resultat clinique. Les resultats des scores des patients atteints de maladie de Kienbock etaient inferieurs a ceux des cas post-traumatiques, sans qu’une difference statistique significative n’ait pu etre mise en evidence.PURPOSE OF THE STUDY Resection of the proximal row of the carpus which simplifies the radiocarpal joint is mainly performed for advanced collapse. With the development of several therapeutic alternatives, further study of outcome is warranted to better identify indications. MATERIAL AND METHODS Twenty-five patients who underwent proximal row carpectomy between January 1999 and February 2004 were reviewed clinically and radiologically at 30 months mean follow-up. Three main etiologies were noted: scaphoid fracture (n=9), scapholunate dissociation (n=9), Kienböck disease (n=6). A posterior approach was used for all patients. Outcome was assessed clinically (pain, force, mobility), radiologically (carpal height, radiocapital space), and subjectively by the patient. Resumption of occupational activity was noted as were the Cooney and Culp scores. RESULTS Average flexion-extension was 60 degrees . Average wrist force was 65% of the healthy side. Pain improved in 88% of wrists and the mean subjective score was 15.2. The mean Cooney and Culp scores were 58 and 67.8 respectively. A reduction in the height of the new articular space was not correlated with less favorable clinical outcome. Outcome in patients with Kienböck disease were less favorable than in trauma patients but the difference did not reach significance. DISCUSSION First row carpectomy is a paliative procedure which should only be performed when conservative treatment is no longer a valid option. Indications should be limited to Watson grade II, before cartilaginous damage affects the head of the capitatum. New techniques such as fusion-shortening, theoretically similar to resection, can now be used for advances collapse. We prefer resection over four-bone arthrodesis because of the lower risk of complications. In Kienböck disease, first row carpectomy should only be used for selected patients (Lichtmann III) due to the risk of early degeneration of the capitatum and radius heads.