ArUco-based stylus reliability for reproductible 3D digitalisation of shoulder cartilage contours.

Imaging techniques in anatomy have developed rapidly over the last decades through the emergence of various 3D scanning systems. Depending on the dissection level, non-contact or tactile contact methods can be applied on the targeted structure. The aim of this study was to assess the inter and intra-observer reproducibility of an ArUco-based localisation stylus, that is, a manual technique on a hand-held stylus. Ten fresh-frozen, unembalmed adult arms were used to digitalise the glenoid cartilage related to the glenohumeral joint and the contour of the clavicle cartilage related to the acromioclavicular joint. Three operators performed consecutive digitalisations of each cartilage contour using an ArUco-based localisation stylus recorded by a single monocular camera. The shape of each cartilage was defined by nine shape parameters. Intra-observer repeatability and inter-observer reproducibility were computed using an intra-class correlation (ICC) for each of these parameters. Overall, 35.2 ± 2.4 s and 26.6 ± 10.2 s were required by each examiner to digitalise the contour of a glenoid and acromioclavicular cartilage, respectively. For most parameters, good-to-excellent agreements were observed concerning intra-observer (ICC ranging between 0.81 and 1.00) and inter-observer (ICC ranging between 0.75 and 0.99) reproducibility. To conclude, through a fast and versatile process, the use of an ArUco-based localisation stylus can be a reliable low-cost alternative to conventional imaging methods to digitalise shoulder cartilage contours.

Three-dimensional reconstruction and virtual reposition of fragments compared to two dimensional measurements of midshaft clavicle fracture shortening.

BACKGROUND: Midshaft clavicle fracture shortening measurement is a reported key element for indication to surgical management and reporting of clinical trials. Determination of pre-fracture clavicle length for shortening measurement remains an unresolved issue. The purpose of the study was to assess accuracy of a novel technique of three-dimensional reconstruction and virtual reposition of bone fragments (3D-VR) for determination of pre-fracture clavicle length and measurement of shortening. METHODS: Accuracy of 3D-VR measurements was assessed using 5 synthetic bone clavicle fracture models. Measurements were compared between caliper and 3D-VR technique measurements. Correlation between 3D-VR and 2D measurements on standard radiographs was assessed on a cohort of 20 midshaft fractures. Four different methods for 2D measurements were assessed. RESULTS: Mean difference between caliper measurements and 3D-VR was 0.74 mm (95CI = - 2.51;3.98) (p = 0.56) on synthetic fracture models. Mean differences between 3D-VR and standard radiograph shortening measurement methods were 11.95 mm (95CI = 7.44;16.46) for method 1 (Jeray et al.) and 9.28 mm (95CI = 4.77;13.79) for method 2 (Smekal et al.) (p < 0.05). Differences were - 1.02 mm (95CI = - 5.53;3.48) for method 3 (Silva et al.) and - 2.04 mm (95CI = - 6.55;2.47) for method 4 (own method). Interobserver correlation ranged between 0.85 and 0.99. A false positive threshold of 20 mm was measured by the two observers in 25% of the case according to method of method 1, 30-35% with method 2, 15% with method 3 et al. and 5-10% with the method 4. CONCLUSION: 3D VR is accurate in measuring midshaft clavicle fracture length and shortening. Two dimensional measurements may be used for approximation of clavicular shortening.

[Therapeutic approaches for proximal humerus fractures]. / Approches thérapeutiques des fractures de l'humérus proximal.

Proximal humerus fracture (PHF) is the 3rd most common fracture over age 65, and its incidence increases with age. The combination of an aging population and a high incidence in geriatric patients constitute a serious potential public health concern. The treatment of PHF is debated. Recent publications report similar results of conservative versus surgical treatment in several types of fractures. Therapeutic decision based on a multiparametric analysis is recommended, there is yet no consensus on the parameters to be analyzed. A recent study suggests taking into consideration individual parameters in deciding the therapeutic strategy and provides a pragmatic treatment algorithm. We propose here a simplified version of this algorithm, guiding therapeutic decision between conservative treatment, osteosynthesis and arthroplasty.

La fracture de l'humérus proximal (FHP) est la troisième fracture la plus fréquente au-delà de 65 ans, et son incidence augmente avec l'âge. Avec le vieillissement de la population, l'incidence des FHP devrait augmenter ces prochaines années, en en faisant un véritable problème de santé publique. Leur traitement est un débat d'actualité. Des publications récentes rapportent des résultats similaires entre traitement conservateur et traitement chirurgical dans plusieurs types de FHP. Concernant le choix de traitement, une décision basée sur une analyse multiparamétrique est recommandée mais les paramètres à considérer ne font actuellement pas l'objet d'un consensus. Nous proposons ici un algorithme basé sur celui d'une étude récente, permettant de guider la décision thérapeutique entre traitement conservateur, ostéosynthèse et arthroplastie.

[Diagnosis of athlete's elbow injuries]. / Diagnostic des lésions du coude de l'athlète.

The elbow joint is highly congruent and subject to less stress than other joints. This contributes to a rather low incidence of pathologies in the general population. However, in athletes who perform repeated movements with supraphysiological forces, diverse pathologies may appear. The objective of this article is to develop an anatomopathological approach to elbow pain in order to identify its origin. A rapid and precise diagnosis allows initiating an adequate treatment and minimizing time of sporting activity arrest.

L'articulation du coude est soumise à des contraintes mécaniques moindres que d'autres articulations et présente une importante congruence. Ces éléments contribuent à la faible incidence des pathologies qui l'affectent dans l'ensemble de la population. Toutefois, chez le sportif qui effectue des mouvements répétés et avec des forces supraphysiologiques, de multiples lésions peuvent survenir. L'objectif de cet article est de développer une démarche anatomopathologique pour le diagnostic des douleurs de coude. Un diagnostic rapide et précis permet la mise en place d'un traitement adéquat ainsi que de minimiser le temps d'arrêt de l'activité sportive.

Revision of failed shoulder arthroplasty: epidemiology, etiology, and surgical options.

BACKGROUND: Our aim was to analyze the epidemiology, etiologies, and revision options for failed shoulder arthroplasty from 2 tertiary centers. METHODS: From 1993 to 2013, 542 failed arthroplasties were revised in 540 patients (65% women): 224 hemiarthroplasties (HAs, 41%), 237 anatomic total shoulder arthroplasties (TSAs, 44%) and 81 reverse total arthroplasties (RSAs, 15%). Data about patients, pathology, and reintervention procedures, as well as intraoperative data, were analyzed from our 2 local registries that prospectively captured all the revision procedures. Patients had an average follow-up period of 8.7 years. RESULTS: The revision rate was 12.7% for HAs, 6.7% for TSAs, and 3.9% for RSAs. HAs were revised earlier (33 ± 40 months) than RSAs (47 ± 150 months) and TSAs (69 ± 61 months). Glenoid failure was a major cause of reintervention: erosion in HAs (29%) or loosening in TSAs (37%) and RSAs (24%). Instability was another major cause of reintervention: 32% in RSAs, 20% in TSAs, and 13% in HAs. Humeral implant loosening led to revision in 10% of RSAs, 6% of HAs, and 6% of TSAs. Multiple reinterventions were required in 21% of patients, mainly for instability (26%) and/or infection (25%). The final implant was an RSA in 48%, especially when associated with cuff insufficiency, instability, and/or bone loss. Final reimplantation was possible in 90% of cases, with the remaining 10% treated with a resection or spacer. CONCLUSION: Glenoid failure and instability are the most common causes of revision. Soft-tissue insufficiency and/or infection results in multiple revisions. Surgeons must recognize all complications so that they can be addressed at the first revision operation and avoid further reinterventions. RSA was the most common final revision implant.

[Arthroscopic surgery for elbow stiffness]. / Chirurgie arthroscopique de la raideur articulaire du coude.

Arthroscopic management of elbow stiffness offers several potential advantages over conventional open procedures. Projected increased joint visualization, decreased tissue disruption and faster recovery have yielded growing interest for this procedure. Elbow arthroscopy remains a challenging procedure and reported complication rate is higher than in other joints. Sound local anatomy knowledge is required to ensure a safe procedure. We report here our indications techniques and postsurgical care protocols for arthroscopic management of osseous, soft tissue and neurological lesions associated with elbow stiffness.

La prise en charge arthroscopique des raideurs articulaires de coude présente plusieurs avantages potentiels par rapport aux techniques conventionnelles ouvertes. La perspective d'une meilleure visualisation de l'articulation ainsi que la minimisation des perturbations tissulaires et la recherche d'une accélération de la convalescence ont généré un intérêt croissant pour cette technique. L'arthroscopie de coude est cependant une procédure techniquement exigeante, dont le taux de complications rapporté est plus important que pour d'autres articulations. Une connaissance approfondie de l'anatomie locale est nécessaire pour assurer la sécurité de la procédure. Nous rapportons ici nos indications, techniques et protocoles postopératoires pour la prise en charge des lésions osseuses, tissulaires et neurologiques constitutives de la raideur de coude.

Internal impingement of the shoulder in overhead athletes: Retrospective multicentre study in 135 arthroscopically-treated patients.

BACKGROUND: Internal impingement of the shoulder (IIS) is the leading cause of chronic shoulder pain in overhead throwing athletes. No consensus exists about which techniques are optimal when surgery is in order. The available studies are limited by small sample sizes and short follow-ups. The primary objective of this study was to assess return-to-sports (RtS) outcomes after surgical treatment for IIS. A favourable RtS outcome (RtS+) was defined as returning to the previous sport at the same or a higher level. HYPOTHESIS: The main hypothesis was that surgical treatment resulted in an RtS+ outcome. The secondary hypothesis was that epidemiological factors, pre- and intra-operative anatomical factors, and specific surgical procedures were associated with higher RtS+ rates. MATERIAL AND METHODS: A retrospective multicentre design was used. We included 135 patients with IIS managed arthroscopically using any of the following procedures: anterior capsulorrhaphy, posterior capsulotomy/capsulectomy, postero-superior labral debridement, posterior glenoidplasty, and rotator cuff tear debridement or repair. Follow-up was at least 1 year. The patients were divided into two groups based on whether they had an RtS+ outcome as defined above or an RtS- outcome defined as a return to the previous sport at a lower level, a switch to another sport, or an inability to engage in any sport. The Kerlan-Jobe Orthopaedic Clinic (KJOC) and Constant's score were used to evaluate subjective and objective shoulder function. RESULTS: Mean follow-up was 7.9 years. Of the 135 patients, 120 (90%) returned to sports after surgery including 70 (52%) to the previous sport at the same level (RtS+ outcome). By univariate analysis, the following factors were associated with an RtS+ outcome: male sex, rotator cuff tear documented intra-operatively, absence of a greater tuberosity cyst on pre-operative imaging studies, and cuff tear debridement. Anterior capsulorrhaphy was associated with worse post-operative pain. DISCUSSION: The RtS+ rate in this study differed from previously reported values, due to differences in the sports practiced by the patients and to considerable variability in the surgical techniques used. The positive association between presence of a rotator cuff tear and an RtS+ outcome is at variance with most of the previously published data. Some of the apparent discrepancies between our results and those from other countries may be ascribable to differences in the most popular sports. LEVEL OF EVIDENCE: IV.

Internal impingement of the shoulder: An international survey of 261 orthopaedic surgeons.

BACKGROUND: Internal impingement of the shoulder (IIS) is a specific disorder of young overhead-throwing athletes that was first described in 1991. The many non-operative and surgical treatments suggested to date have produced mixed outcomes. The objective of this study was to compare the practices of surgeons in France versus other countries regarding the diagnosis and treatment of IIS. HYPOTHESIS: Diagnostic and therapeutic practices regarding IIS differ between surgeons in France and in other countries. MATERIAL AND METHODS: A 21-item questionnaire in French and English was emailed to the 1300 members of the French Arthroscopy Society and to surgeons from countries other than France. The questionnaire collected information on knowledge about IIS (2 items), the frequency of IIS in clinical practice (2 items), the diagnosis of IIS (6 items), the non-operative and surgical treatment of IIS (3 and 5 items, respectively), and return-to-sports rates after treatment for IIS (3 items). RESULTS: The completed questionnaire was sent back by 261 surgeons, 206 in France and 55 in other countries, including 42 in Japan. Among the respondents, 90% knew about IIS. Experience with IIS in terms of number of patients seen or surgical treatments performed was greater in the international group (45% vs. 19% in France, p<0.001). Posterior shoulder pain in the arm cocking position was the most widely recognised symptom (99% in France, 74% internationally, p<0.001), followed by excessive external rotation during arm abduction (55% vs. 65%, p=0.23). The most commonly sought lesions were those of the postero-superior labrum and articular surface of the rotator cuff. Rotator cuff debridement was among the surgical options according to most respondents (74% vs. 70%). In contrast, postero-superior glenoidplasty was cited almost only by surgeons in France (67% vs. 4%, p<0.001). The proportion of patients who are able to return to sports was estimated at 50% to 75% by most respondents. DISCUSSION: Most respondents had theoretical knowledge about IIS, but surgery was rarely performed in France. Only very few athletes in France play baseball, which is responsible for most sports injuries of the shoulder seen in Japan. This fact, combined with differences in the lesions or even the diagnoses, may have contributed to the differences in the responses to the survey items between the French and international groups.

Non-hip/non-vertebral fractures - How to treat best?

Fractures of the extremities in the elderly constitute more than two-thirds of all fragility fractures befalling frail, osteoporotic and sarcopenic patients. Although treatment controversies abound, consensus exists. Upper extremity fractures hinder activities of daily living and are debilitating. Open fractures or displaced fractures will need surgical intervention. Wrist fractures treated operatively allow early use of the hand. Most pelvic fractures are treated conservatively. In the lower extremities, fractures of the long bones, tibia and femur need surgical intervention. Non-displaced fractures around the foot may be treated with immobilisation and avoidance of full weight-bearing. As a rule, fractures take four months for consolidation. Individually tailored solutions are needed for frail patients with comorbidities. Maintaining joint mobility and muscle strength preserves mobility and autonomy. Caring for extremities trauma is team work, involving family and health care providers. Prevention efforts are mandatory.

Is posterosuperior contact a normal occurrence in the shoulder?

Posterosuperior (or internal) impingement at the shoulder is defined as contact between the underside of the supraspinatus or infraspinatus tendons with the posterosuperior labrum during extreme external rotation and abduction. In many cases, this contact damages the tendon and causes mirror posterosuperior labrum deterioration. The primary aim of this study was to define whether this contact occurs normally in patients who do not have a rotator cuff tear. METHODS: We evaluated 100 shoulders in 100 patients. All patients were operated on in the beach chair position. After introducing the scope through the posterior portal, contact between the articular side of the rotator cuff and the posterosuperior labrum was noted as being present or absent when the arm was cocked in 90° abduction and 90° external rotation (90/90) then the arm was cocked in 140° abduction and maximum external rotation (140/Max). RESULTS: Contact was observed in 69% of patients in the 90/90 cocked position and in 94% of patients in the 140/Max cocked position. We found a correlation between the presence of rotator cuff and/or labrum lesions and the patient regularly performing arm-cock movements (p=0.035). DISCUSSION: Contact between the underside of the supraspinatus tendon and the posterosuperior labrum occurs physiologically. Repetitive arm-cock movements may contribute to macroscopic lesions of the underside of the rotator cuff and posterosuperior labrum. LEVEL OF EVIDENCE: IV, basic science study.

[Management of a first-time dislocation in the athlete]. / Prise en charge d'un premier épisode de luxation antéro-inférieure de l'épaule chez l'athlète.

Management of a first-time dislocation in the athlete patient is challenging. This patient population has important requirements with high expectations and deadlines to meet, especially if the trauma occurs during high season. As initial management is usually conservative with immobilization followed by rehabilitation, some authors support the role of primary surgical treatment in high risk athletes. Indication for surgery and choice of surgical technique is based on an algorithm incorporating risk factors for recurrence and the presence of concomitant bony lesions on the humeral and glenoid sides. Return to sport varies from 3 to 6 months depending on the type of sport practiced.

La luxation gléno-humérale chez l'athlète présente un challenge particulier dans la prise en charge. Cette population de patients a des exigences importantes avec des échéances à respecter dans son programme, surtout si le traumatisme a lieu en pleine saison. Si la prise en charge initiale consiste en un traitement conservateur comprenant une immobilisation suivie d'une réédu-cation musculaire, certains auteurs préconisent une stabilisation chirurgicale d'emblée chez les patients à haut risque de récidive. Le choix de la chirurgie et de sa technique se fait en fonction d'un algorithme basé sur les facteurs de risque de récidive ainsi que la présence de lésions concomitantes. Le retour au sport varie de 3 à 6 mois selon le type de sport pratiqué.

The greater tuberosity angle: a new predictor for rotator cuff tear.

BACKGROUND: The implication of scapular morphology in rotator cuff tears has been extensively studied. However, the role of the greater tuberosity (GT) should be of equal importance. The aim of this study was to propose a new radiographic marker, the GT angle (GTA), which measures the position of the GT in relation to the center of rotation of the humeral head. The hypothesis was that a higher angle value would be associated with a higher likelihood in detecting a rotator cuff tear. METHODS: During 1 year, patients were prospectively recruited from a single institution specialized shoulder clinic in 2 different groups. The patient group consisted of individuals with a degenerative rotator cuff tear involving at least the supraspinatus. The control group consisted of individuals with no rotator cuff pathology. Individuals in both groups with congenital, post-traumatic, or degenerative alterations of the proximal humerus were excluded. The GTA was measured on an anteroposterior shoulder x-ray image with the arm in neutral rotation by 3 observers at 2 different times. RESULTS: The study recruited 71 patients (33 patients, 38 controls). Mean GTA value was 72.5° (range, 67.6°-79.2°) in patients and 65.2° (range, 55.8°-70.5°) for controls (P <.001). A value above 70° resulted in 93-fold higher odds of detecting a rotator cuff tear (P <.001). Interobserver and intraobserver reliability were high. CONCLUSIONS: GT morphology is implicated in rotator cuff tears. The GTA is a reliable radiographic marker, with more than 70° being highly predictive in detecting such lesions.

Automated Three-Dimensional Measurement of Glenoid Version and Inclination in Arthritic Shoulders.

BACKGROUND: Preoperative computed tomography (CT) measurements of glenoid version and inclination are recommended for planning glenoid implantation in shoulder arthroplasty. However, current manual or semi-automated 2-dimensional (2D) and 3-dimensional (3D) methods are user-dependent and time-consuming. We assessed whether the use of a 3D automated method is accurate and reliable to measure glenoid version and inclination in osteoarthritic shoulders. METHODS: CT scans of osteoarthritic shoulders of 60 patients scheduled for shoulder arthroplasty were obtained. Automated, surgeon-operated, image analysis software (Glenosys; Imascap) was developed to measure glenoid version and inclination. The anatomic scapular reference planes were defined as the mean of the peripheral points of the scapular body as well as the plane perpendicular to it, passing along the supraspinatus fossa line. Measurements were compared with those obtained using previously described manual or semi-automated methods, including the Friedman version angle on 2D CTs, Friedman method on 3D multiplanar reconstructions (corrected Friedman method), Ganapathi-Iannotti and Lewis-Armstrong methods on 3D volumetric reconstructions (for glenoid version), and Maurer method (for glenoid inclination).The mean differences (and standard deviation) and the concordance correlation coefficients (CCCs) were calculated. Two orthopaedic surgeons independently examined the images for the interobserver analysis, with one of them measuring them twice more for the intraobserver analysis; interobserver and intraobserver reliability was calculated using the intraclass correlation coefficients (ICCs). RESULTS: The mean difference in the Glenosys glenoid version measurement was 2.0° ± 4.5° (CCC = 0.93) compared with the Friedman method, 2.5° ± 3.2° (CCC = 0.95) compared with the corrected Friedman method, 1.5° ± 4.5° (CCC = 0.94) compared with the Ganapathi-Iannotti method, and 1.8° ± 3.8° (CCC = 0.95) compared with the Lewis-Armstrong method. There was a mean difference of 0.2° ± 4.7° (CCC = 0.78) between the inclination measurements made with the Glenosys and Maurer methods. The difference between the overall average 2D and 3D measurements was not significant (p = 0.45). CONCLUSIONS: Use of fully automated software for 3D measurement of glenoid version and inclination in arthritic shoulders is reliable and accurate, showing excellent correlation with previously described manual or semi-automated methods. CLINICAL RELEVANCE: The use of automated surgeon-operated image analysis software to evaluate 3D glenoid anatomy eliminates interobserver and intraobserver discrepancies, improves the accuracy of preoperative planning for shoulder replacement, and offers a potential gain of time for the surgeon.

Shoulder strengthening exercises adapted to specific shoulder pathologies can be selected using new simulation techniques: a pilot study.

PURPOSE: Shoulder strength training exercises represent a major component of rehabilitation protocols designed for conservative or postsurgical management of shoulder pathologies. Numerous methods are described for exercising each shoulder muscle or muscle group. Limited information is available to assess potential deleterious effects of individual methods with respect to specific shoulder pathologies. Thus, the goal of this pilot study was to use a patient-specific 3D measurement technique coupling medical imaging and optical motion capture for evaluation of a set of shoulder strength training exercises regarding glenohumeral, labral and subacromial compression, as well as elongation of the rotator cuff muscles. METHODS: One volunteer underwent magnetic resonance imaging (MRI) and motion capture of the shoulder. Motion data from the volunteer were recorded during three passive rehabilitation exercises and twenty-nine strengthening exercises targeting eleven of the most frequently trained shoulder muscles or muscle groups and using four different techniques when available. For each exercise, glenohumeral and labral compression, subacromial space height and rotator cuff muscles elongation were measured on the entire range of motion. RESULTS: Significant differences in glenohumeral, subacromial and labral compressions were observed between sets of exercises targeting individual shoulder muscles. Muscle lengths computed by simulation compared to MRI measurements showed differences of 0-5%. CONCLUSIONS: This study represents the first screening of shoulder strengthening exercises to identify potential deleterious effects on the shoulder joint. Motion capture combined with medical imaging allows for reliable assessment of glenohumeral, labral and subacromial compression, as well as muscle-tendon elongation during shoulder strength training exercises.

Angled BIO-RSA (bony-increased offset-reverse shoulder arthroplasty): a solution for the management of glenoid bone loss and erosion.

BACKGROUND: Glenoid deficiency and erosion (excessive retroversion/inclination) must be corrected in reverse shoulder arthroplasty (RSA) to avoid prosthetic notching or instability and to maximize function, range of motion, and prosthesis longevity. This study reports the results of RSA with an angled, autologous glenoid graft harvested from the humerus (angled BIO-RSA). METHODS: A trapezoidal bone graft, harvested from the humeral head and fixed with a long-post baseplate and screws, was used to compensate for residual glenoid bone loss/erosion. For simple to moderate (<25°) glenoid defects, standardized instrumentation combined with some eccentric reaming (<15°) was used to reconstruct the glenoid and obtain neutral implant alignment. For severe (>25°) and complex (multiplanar) glenoid bone defects, patient-specific grafts and guides were used after 3-dimensional planning. Patients were reviewed with minimum 2 years of follow-up. Mean follow-up was 36 months (range, 24-81 months). Preoperative and postoperative measurements of inclination and version were performed in the plane of the scapula on computed tomography images. RESULTS: The study included 54 patients (41 women, 13 men; mean 73 years old). Fifteen patients had combined vertical and horizontal glenoid bone deficiency. Among E2/E3 glenoids, inclination improved from 37° (range, 14° to 84°) to 10.2° (range -28° to 36°, P < .001). Among B2/C glenoids, retroversion improved from -21° (range, -49° to 0°) to -10.6° (-32° to 4°, P = .06). Complete radiographic incorporation of the graft occurred in 94% (51 of 54). Complications included infection in 1 and clinical aseptic baseplate loosening in 2. Mild notching occurred in 25% (13 of 51) of patients. Constant-Murley and Subjective Shoulder Value assessments increased from 31 to 68 and from 30% to 83%, respectively (P < .001). CONCLUSION: Angled BIO-RSA predictably corrects glenoid deficiency, including severe (>25°) multiplanar deformity. Graft incorporation is predictable. Advantages of using an autograftharvested in situ include bone stock augmentation, lateralization, low donor-site morbidity, low relative cost, and flexibility needed to simultaneously correct posterior and superior glenoid defects.

[Rehabilitation after rotator cuff repair: developments and recommendations]. / Rééducation après chirurgie de la coiffe des rotateurs: développements et recommandations.

Rehabilitation post surgical repair of the rotator cuff is an important determinant of the quality of the healing process, and of the clinical and functional results. Techniques used have been reported to favor certain of those parameters at the expense of others. Several approaches have been proposed; none has reached a consensus yet. The level of evidence in the literature does not allow for definitive recommendations and elaborating a protocol relies on clinical experience as well as expert opinion, incorporating scientific data. An initial period of rest with limited passive motion emerges though as an approach suited to the treatment of most clinical situations.

Risk factors for post-traumatic osteoarthritis of the ankle: an eighteen year follow-up study.

PURPOSE: Long-term studies evaluating risk factors for development of ankle osteoarthritis (OA) following malleolar fractures are sparse. METHODS: We conducted a retrospective cohort study including consecutive patients treated by open reduction and internal fixation for malleolar fracture between January 1988 and December 1997. Perioperative information was obtained retrospectively. Patients were evaluated clinically and radiographically 12-22 years postoperatively. Radiographic ankle OA was determined on standardised radiographs using the Kellgren and Lawrence scale (grade 3-4=advanced OA). Uni- and multivariate regression analyses were performed to determine risk factors for OA. RESULTS: During the inclusion period, 373 fractures (372 patients; 9% Weber A, 58% Weber B, 33% Weber C) were operated upon. The mean age at operation was 42.9 years. There were 102 patients seen at follow-up (mean follow-up 17.9 years). Those not available did not differ in demographics and fracture type from those seen. Advanced radiographic OA was present in 37 patients (36.3%). Significant risk factors were: Weber C fracture, associated medial malleolar fracture, fracture-dislocation, increasing body mass index, age 30 years or more and length of time since surgery. CONCLUSIONS: Advanced radiographic OA was common 12-22 years after malleolar fracture. The probability of developing post-traumatic OA among patients having three or more risk factors was 60-70%.

[Orthopaedic management of long bones metastasis]. / Prise en charge orthopédique des métastases des os longs.

The recent progress in oncologic management of patients with metastatic disease has permitted a significant improvement of their life expectancy. Many of these patients will suffer from complications related to bone metastasis. Unfortunately an orthopaedic treatment is seldom offered to them, mainly because of the misconception that this would not bring them any benefice. However these patients are often good candidates for an orthopaedic management, which objectives are to relieve pain and to re-establish their quality of life. The available surgical techniques are well described and the management protocols are clearly defined, as are the expectable complications and the errors that must not be done.

Myogenic precursor cell transplantation in pigs: a step towards a clinical use for muscle regeneration?

It is most probable that, in a near future, myogenic precursor cell transplants will have clinical applications in domains as different as orthopaedics, endocrinology, management of heart infarct, and therapies of muscle diseases. We have proposed to introduce the use of myogenic precursor cell transplantation in patients, after preliminary tests in a large animal model, the pig. Our initial effort was centred on the domain of orthopaedics. Muscle damages are frequent complications of traumas and sport accidents with serious consequences both in terms of disabilities and health economics. Often these lesions heal very poorly. A number of growth factors seemed successful as healing agents but they are difficult to deliver clinically. The goal was to use ex vivo somatic gene therapy with myogenic precursor cells modified to secrete growth factors with the aim of improving muscle healing in patients and of demonstrating the potential of this technology. To do so, we used a suitable large animal model, the pig, for exploring myogenic precursor cell transplantation strategies that could be used in patients.

Calcium sources used by post-natal human myoblasts during initial differentiation.

Increases in cytoplasmic Ca(2+) are crucial for inducing the initial steps of myoblast differentiation that ultimately lead to fusion; yet the mechanisms that produce this elevated Ca(2+) have not been fully resolved. For example, it is still unclear whether the increase comes exclusively from membrane Ca(2+) influx or also from Ca(2+) release from internal stores. To address this, we investigated early differentiation of myoblast clones each derived from single post-natal human satellite cells. Initial differentiation was assayed by immunostaining myonuclei for the transcription factor MEF2. When Ca(2+) influx was eliminated by using low external Ca(2+) media, we found that approximately half the clones could still differentiate. Of the clones that required influx of external Ca(2+), most clones used T-type Ca(2+) channels, but others used store-operated channels as influx-generating mechanisms. On the other hand, clones that differentiated in low external Ca(2+) relied on Ca(2+) release from internal stores through IP(3) receptors. Interestingly, by following clones over time, we observed that some switched their preferred Ca(2+) source: clones that initially used calcium release from internal stores to differentiate later required Ca(2+) influx and inversely. In conclusion, we show that human myoblasts can use three alternative mechanisms to increase cytoplasmic Ca(2+) at the onset of the differentiation process: influx through T-types Ca(2+) channels, influx through store operated channels and release from internal stores through IP(3) receptors. In addition, we suggest that, probably because Ca(2+) elevation is essential during initial differentiation, myoblasts may be able to select between these alternate Ca(2+) pathways.