Eric Vandenbussche

A 4-portal arthroscopic stabilization in posterior shoulder instability.

The purpose of this study was to present an arthroscopic stabilization technique with 4 portals for posterior instability used in 11 patients (13 shoulders). There were 7 male and 4 female patients. All patients had an arthroscopic labral suture with anchors and capsular plication with 4 portals. The follow-up period averaged 34 months. No complication or recurrence of instability was noted. A moderate loss of range of motion was noted in 4 shoulders and moderate pain in 2 shoulders. All patients were satisfied. According to the literature, the rate of recurrence of instability is currently lower than 12% when a labral suture and capsular plication are performed. Our results for pain and range of motion are similar to those described in recent publications. However, we think that the 4-portal technique allows a facilitated access to the posteroinferior part of the glenoid and reduces the rate of postoperative instability.

Hemispheric cups do not reproduce acetabular rim morphology

Background Iliopsoas impingement is a recurrent complication following THA, caused by muscle friction against a protrusive prosthetic cup.This study was designed to quantify the dimensional variations in acetabular rim proiles, with particular regard to the iliopubic valley, in order to suggest means to prevent iliopsoas impingement. Material and methods 34 cadaver pelvises were analyzed using a hip navigation system.The morphometric data were processed to plot proiles of all acetabular rims with particular regard to the shape and depth of the psoas valley. Results The acetabular rim is an asymmetric succession of 3 peaks and 3 troughs.The psoas valley is a salient feature in most pelvises and there is only a weak correlation between its depth (mean 3.8 mm, SD 2.0) and acetabular diameter, anteversion, or inclination. Interpretation It would be dificult to obviate the anterior overlap of the acetabulum using a hemispheric cup, a fortiori in certain morphotypes, without compromising range of motion or risk of dislocation.The solution for prevention of iliopsoas impingement would be to adapt cup design to acetabular anatomy, which may require different implants for the right and left sides, and hence a doubled inventory.

Accuracy of Glenoid Component Placement in Total Shoulder Arthroplasty and Its Effect on Clinical and Radiological Outcome in a Retrospective, Longitudinal, Monocentric Open Study

Background The success of Total Shoulder Arthroplasty (TSA) is believed to depend on the restoration of the natural anatomy of the joint and a key development has been the introduction of modular humeral components to more accurately restore the patient’s anatomy. However, there are no peer-reviewed studies that have reported the degree of glenoid component mal-position achieved in clinical practice and the clinical outcome of such mal-position. The main purpose of this study was to assess the accuracy of glenoid implant positioning during TSA and to relate it to the radiological (occurrence of radiolucent lines and osteolysis on CT) and clinical outcomes. Methods 68 TSAs were assessed with a mean follow-up of 38+/−27 months. The clinical evaluation consisted of measuring the mobility as well as of the Constant Score. The radiological evaluation was performed on CT-scans in which metal artefacts had been eliminated. From the CT-scans radiolucent lines and osteolysis were assessed. The positions of the glenoid and humeral components were also measured from the CT scans. Results Four position glenoid component parameters were calculated The posterior version (6°±12°; mean ± SD), the superior tilt (12°±17°), the rotation of the implant relative to the scapular plane (3°±14°) and the off-set distance of the centre of the glenoid implant from the scapular plane (6±4 mm). An inferiorly inclined implant was found to be associated with higher levels of radiolucent lines while retroversion and non-neutral rotation were associated with a reduced range of motion. Conclusion this study demonstrates that glenoid implants of anatomic TSA are poorly positioned and that this malposition has a direct effect on the clinical and radiological outcome. Thus, further developments in glenoid implantation techniques are required to enable the surgeon to achieve a desired implant position and outcome.

Arthroplastie de hanche à couple métal-métal sur polyéthylène cimenté: Résultats à moyen terme

PURPOSE OF THE STUDY Metal-on-metal bearings in total hip arthroplasty may, in theory, provide an effective answer to osteolysis in active patients. The purpose of this retrospective study was to evaluate the results of a consecutive series of Metasul total hip arthroplasties with a cemented socket. MATERIAL AND METHODS The series was composed of 28 total hip arthroplasties in 23 patients (13 women and 10 men). The mean age at operation was 44 +/- 8.3 years (range 22-59 years). The initial diagnosis was osteoarthritis (14 hips), osteonecrosis of the femoral head (11 hips) and rheumatoid arthritis (3 hips). Cemented cups with a metal articulation surface molded into the polyethylene were used. The cup was articulated with a 28-mm metallic head. Cemented stems were used in 27 hips, whereas a hydroxyapatite coated stem was implanted in one hip. RESULTS One hip required revision for deep infection five months postoperatively. One patient (one hip) was lost to follow-up. Twenty-six hips were evaluated at an average 31-month follow-up (range 12-47 months). All hips were rated excellent or very good. Radiographically, seven hips (27%) had a progressive acetabular radiolucent line, including three complete radiolucent lines. The latter always were located at the bone-cement interface. No implant migration was noted. In these cases, the mean socket diameter was lower than for the rest of the cohort (p < 0.001). DISCUSSION AND CONCLUSION Progression of acetabular radiolucent lines remains of concern in this series of Metasul artificial hips. It is hypothesized that the diminution of polyethylene thickness has led to an increased rigidity of the socket, resulting in a higher rate of constraints at the bone-cement interface. Special attention must be given to these hips.

Surgical treatment of three and four-part proximal humeral fractures

Three- and four-part fractures of the proximal humerus are usually treated surgically. Open reduction with internal fixation (ORIF) is the method of choice in younger patients. Anatomic reduction of the tuberosities is crucial to ensure that, in the event of poorly tolerated avascular necrosis of the humeral head, hemiarthroplasty can be performed under optimal conditions. Suboptimal outcomes may occur after ORIF, as less-than-perfect reduction and fixation is poorly tolerated at the shoulder. Preoperative computed tomography must be performed routinely to analyse fragment displacement and comminution, classify the fracture, assess humeral head vitality, and evaluate the mechanical properties of the underlying bone. Fracture reduction relies on principles that are shared by the various available techniques. Reduction of each fragment should be assessed separately. Reduction of the humeral head to the shaft should be performed before reduction of the tuberosities. The fixation technique should ensure stability of the anatomic reduction, with secure fixation of the tuberosities and a minimal risk of material migration into the joint. Here, we provide a detailed discussion of the various techniques, with their advantages and drawbacks, to help surgeons select the method that is most appropriate to each individual patient.

Do Dual-Mobility Cups Reduce the Risk of Dislocation in Total Hip Arthroplasty for Fractured Neck of Femur in Patients Aged Older Than 75 Years?

BACKGROUND Total hip arthroplasty (THA) for intracapsular neck of femur (NOF) fracture remains debatable as it is associated with higher rates of dislocation, notably in the older part of the population. We hypothesized this risk could be limited using dual-mobility cups (DMCs). METHODS Eighty-two patients (83 hips) aged older than 75 years underwent DMC-THA using a posterolateral approach for an intracapsular NOF fracture. RESULTS Clinical data were collected in 45 patients at a mean of 23.8 ± 9.4 months (12.1-42 months). The mortality rates were 19% (16 patients) and 36.5% (30 patients) at 1 year postoperatively and at the last follow-up, respectively. Postoperatively, there were 2 dislocations of the large articulation (4.4%) and one intraprosthetic dislocation (2.2%), all related to technical errors. Functional results were rated at least good in 71% cases, whereas the Parker and Devane scores were stable, indicating optimal restoration of autonomy and physical activity. CONCLUSION Although technically demanding, DMC-THA may prevent dislocation in intracapsular NOF fracture in elderly patients, while consistently limiting the risk of loss of independence.

Measurement of femoral head penetration in polyethylene using a 3-dimensional CT-scan technique

Background Current techniques for measuring in vivo polyethylene wear suffer from a range of problems, resulting in an unacceptable lack of repeatability and/or insufficient accuracy when they are used to measure the low wear rates associated with new, highly crosslinked polyethylene. We describe an improved CT method for measurement of 3D femoral head penetration in PE acetabular cups that has sufficient accuracy and repeatability to allow assessment of the wear potential of modern implants. Method The accuracy and repeatability of the CT-scan method was determined by blindly repeating measurements on a precisely calibrated 28-mm prosthetic head and by comparing them with direct metrological measurements on 10 acetabular specimens with in vitro wear from machining, and on 8 explanted acetabular specimens with in vivo wear. Results The intra- and interobserver errors in femoral head diameter were 0.036 mm (SD 0.044) and 0.050 mm (SD 0.022), respectively. CT estimated femoral head penetration in both all-poly and metal-backed acetabular components with accuracy ranging from 0.009 to 0.245 mm (mean 0.080; SD 0.067). Interpretation We found that the CT method is rapid, is accurate, and has repeatability and ease of availability. Using a slice thickness of 0.0625 mm, this method can detect wear—and also the threshold for the wear rate that causes osteolysis—much earlier than previous methods.

4 Réinsertion transosseuse proximalisée pour rupture de la coiffe des rotateurs : résultats fonctionnels et anatomiques à long terme

Introduction La reparation des ruptures de la coiffe des rotateurs apporte un benefice fonctionnel regulier. Neanmoins, la cicatrisation tendineuse a ete rarement evaluee, avec des resultats variables selon les techniques et les methodes d’exploration. L’objectif de ce travail etait d’evaluer les resultats fonctionnels et anatomiques des reinsertions transosseuses proximalisees de la coiffe des rotateurs au sein d’une serie retrospective continue. Materiel et Methode Les criteres d’inclusion regroupaient les ruptures transfixiantes de la coiffe des rotateurs reinserees dans une tranchee osseuse proximalisee a ciel ouvert, par un seul operateur, avec un recul minimum de 5 ans. Quarante-huit patients (23 hommes, 25 femmes), soit 50 epaules, ont ete inclus. L’âge moyen etait de 59 ans (40-70 ans). Les lesions comprenaient 35 atteintes isolees du supra spinatus, 8 associations supra spinatus et sub scapularis, 5 associations supra et infra spinatus, et une atteinte des 3 tendons dans 2 cas. Le score de Constant moyen pre operatoire etait de 53 (26-83). L’espace sous acromial (ESA) moyen etait de 9 mm (3-13 mm). La retraction etait classee stade 2 selon Bernageau dans 55 cas sur 67 tendons. L’indice de degenerescence graisseuse (IDG) moyen etait a 0,8 (0-3). Resultats L’etude clinique et radiographique a porte sur 46 epaules (3 PDV, 1 decede) au recul moyen de 7,3 ans (5-11 ans). L’etancheite de la reparation a ete evaluee dans 41 epaules par IRM. Le score de Constant absolu moyen etait de 74 (40-94), significativement ameliore pour tous les items. Une progression de l’arthrose selon Samilson a ete observee dans 4 cas. L’ESA au dernier recul etait a 10 mm (6-14 mm). Une rupture iterative a ete notee dans 4 cas (9,8 %). Elle concernait le supra spinatus 2 fois, l’infra spinatus et le sub scapularis 1 fois. Le score de Constant moyen n’etait pas significativement influence par le statut de la coiffe au dernier recul. Le risque de rupture iterative etait influence par l’etendue de l’atteinte initiale et l’IDG. Discussion La reinsertion transosseuse proximalisee des tendons de la coiffe des rotateurs a donne une majorite de resultats fonctionnels satisfaisants. La progression de l’arthrose gleno-humerale a ete limitee, sans excentration de la tete humerale. La cicatrisation des coiffes operees etait acquise et stable a plus de 7 ans de recul dans 90 % des epaules revues. Cette etude confirme la qualite des resultats anatomiques obtenus par une technique chirurgicale a ciel ouvert, a laquelle doivent etre comparees les techniques recentes.