[Anterior cruciate ligament injuries in children]. / Lésions du ligament croisé antérieur de l'enfant.

An increasing number of anterior cruciate ligament injuries are now seen in children and girls seem to be equally affected. Such neglected or untreated lesions could be the cause of early degenerative changes. Recently, many authors support the trend toward early surgical management in skeletally immature patients with complex meniscal tear or recurrent knee instability after proper rehabilitation. Improvement in pediatric knowledge and surgical techniques tend to support a tendency for more surgical treatment in children. The type of management is choosing according to history and physical examination. Magnetic resonance imaging is a useful tool not only for diagnosis but also for surgical treatment planning. We usually recommend anterior cruciate ligament reconstruction in children with knee instability or with further damages to the joint.

[Overuse injuries in children]. / Lesions de surcharge chez l'enfant.

The physical-activity and sporting at the child and the teenager is probably, in these years 2000, in full change. In a paradoxical way, extremely sporting children or teenagers are living beside extremely sedentary school-boys, neglecting the majority of the physical-activities and preferring a home-lifestyle. In the evaluation of overload sporting lesion of at teenager, it is thus imperative to take into account not only the individual characteristics of the child: its sex, its age, its stage of growth, its psychology, the presence or not of preexistent pathologies or anatomical disorders. It is naturally necessary to wonder about the training methods of the activity, but it appears fundamental to me to evaluate the child from a sensitivo-motor point of view and this can be carried out by assessments physio-therapeutic or aptitude tests carried out by doctors of the sport.

Computer-assisted placement technique in hip resurfacing arthroplasty: improvement in accuracy?

Freehand positioning of the femoral drill guide is difficult during hip resurfacing and the surgeon is often unsure of the implant position achieved peroperatively. The purpose of this study was to find out whether, by using a navigation system, acetabular and femoral component positioning could be made easier and more precise. Eighteen patients operated on by the same surgeon were matched by sex, age, BMI, diagnosis and ASA score (nine patients with computer assistance, nine with the regular ancillary). Pre-operative planning was done on standard AP and axial radiographs with CT scan views for the computer-assisted operations. The final position of implants was evaluated by the same radiographs for all patients. The follow-up was at least 1 year. No difference between both groups in terms of femoral component position was observed (p > 0.05). There was also no difference in femoral notching. A trend for a better cup position was observed for the navigated hips, especially for cup anteversion. There was no additional operating time for the navigated hips. Hip navigation for resurfacing surgery may allow improved visualisation and hip implant positioning, but its advantage probably will be more obvious with mini-incisions than with regular incision surgery.

A bioactive injectable bulking material; a potential therapeutic approach for stress urinary incontinence.

Stress urinary incontinence (SUI) is a life changing condition, affecting 20 million women worldwide. In this study, we developed a bioactive, injectable bulking agent that consists of Permacol™ (Medtronic, Switzerland) and recombinant insulin like growth factor-1 conjugated fibrin micro-beads (fib_rIGF-1) for its bulk stability and capacity to induce muscle regeneration. Therefore, Permacol™ formulations were injected in the submucosal space of rabbit bladders. The ability of a bulking material to form a stable and muscle-inducing bulk represents for us a promising therapeutic approach to achieve a long-lasting treatment for SUI. The fib_rIGF-1 showed no adverse effect on human smooth muscle cell metabolic activity and viability in vitro based on AlamarBlue assays and Live/Dead staining. Three months after injection of fib_rIGF-1 together with Permacol™ into the rabbit bladder wall, we observed a smooth muscle tissue like formation within the injected materials. Positive staining for alpha smooth muscle actin, calponin, and caldesmon demonstrated a contractile phenotype of the newly formed smooth muscle tissue. Moreover, the fib_rIGF-1 treated group also improved the neovascularization at the injection site, confirmed by CD31 positive staining compared to bulks made of PermacolTM only. The results of this study encourage us to further develop this injectable, bioactive bulking material towards a future therapeutic approach for a minimal invasive and long-lasting treatment of SUI.

[Femoro-acetabular impingement]. / Le conflit fémoro-acétabulaire.

Femur-acetabular impingement is a recently discovered etiology of early hip osteoarthritis. Patient history and clinical examination allow to make the diagnosis, whereas the radiological exams allow to find the etiology of impingement. Impingement is related to morphological alterations of the acetabular rim and/or proximal femur, leading to an abnormal contact between the articular components. The localisation of the abnormal morphology determines the type of impingement and the resulting articular damages. Because of the increasing risk of chondral lesions, only an early treatment may eventually improve the prognosis of the hip joint. If primary conservative treatment is unsuccessful in confirmed impingement cases, open or arthroscopic surgical treatment is indicated.

Minimally invasive surgery for adolescent idiopathic scoliosis: correction of deformity and peri-operative morbidity in 70 consecutive patients.

AIMS: The aim of this study was to report a retrospective, consecutive series of patients with adolescent idiopathic scoliosis (AIS) who were treated with posterior minimally invasive surgery (MIS) with a mean follow-up of two years (sd 1.4; 0.9 to 0 3.7). Our objectives were to measure the correction of the deformity and record the peri-operative morbidity. Special attention was paid to the operating time (ORT), estimated blood loss (EBL), length of stay (LOS) and further complications. PATIENTS AND METHODS: We prospectively collected the data of 70 consecutive patients with AIS treated with MIS using three incisions and a muscle-splitting approach by a single surgeon between June 2013 and February 2016 and these were retrospectively reviewed. There were eight male and 62 female patients with a mean age of 15 years (sd 4.5 ) with a mean body mass index of 19.8 kg/m2 (sd 5.4). The curves were classified according to Lenke; 40 curves were type 1, 15 were type 2, three were type 3, two were type 4, eight were type 5 and two were type 6. RESULTS: The mean primary Cobb angle was corrected from 58.9° (sd 12.6°) pre-operatively to 17.7° (sd 10.2°) post-operatively with a mean correction of 69% (sd 20%, p < 0.001). The mean kyphosis at T5 to T12 increased from 24.2° (sd 12.2°) pre-operatively to 30.1° (sd 9.6°, p < 0.001) post-operatively. Peri-operative (30 days) complications occurred in three patients(4.2%): one subcutaneous haematoma, one deep venous thrombosis and one pulmonary complication. Five additional complications occurred in five patients (7.1%): one superficial wound infection, one suture granuloma and three delayed deep surgical site infections. The mean ORT was 337.1 mins (sd 121.3); the mean EBL was 345.7 ml (sd 175.1) and the mean LOS was 4.6 days (sd 0.8). CONCLUSION: The use of MIS for patients with AIS results in a significant correction of spinal deformity in both the frontal and sagittal planes, with a low EBL and a short LOS. The rate of peri-operative complications compares well with that following a routine open technique. The longer term safety and benefit of MIS in these patients needs to be evaluated with further follow-up of a larger cohort of patients. Cite this article: Bone Joint J 2017;99-B:1651-7.

[Gait disorders and lower leg deformities in children]. / Mon enfant marche mat les anomalies du morphotype des membres inférieurs.

Gait disorders and lower legs deformities in children are frequent causes of parental concern and of medical advice. These deformities should be analysed systematically as well as their consequences for daily activities. We should define precisely type, localisation and importance of the deformity: femoral or tibial torsion, knock knees, bow legs. The evaluation should always be done according to age of the child because these deformities are most often a step toward adult morphotype. Sometimes they could be the manifestation of some generalised or localised pathology that should be investigated and treated. Nevertheless patience and explanations, regular follow-up allow to reassure the parents. There is in the great majority of case no place for any conservatrice and especially surgical treatment for theses disorders spontaneously healing in 95% of cases.

Calcium phosphate drug delivery system: influence of local zoledronate release on bone implant osteointegration.

Despite total hip replacement (THR) gives generally satisfactory results, the quality of outcome in young patients is markedly decreased compared to the average THR outcome. For this population, pharmacological treatment with bisphosphonate would be beneficial to decrease the peri-implant osteolysis. However, as this population does not necessarily suffer from osteoporosis, a nonsystemic treatment would be preferable. Zoledronate was then grafted to hydroxyapatite (HA) coating of titanium implants. The implants were inserted in rat condyles with various zoledronate concentrations. A positive concentration-dependent effect was observed on the peri-implant bone density and on different histomorphometric parameters. Importantly for the outcome of the implants, the mechanical fixation was increased by the local presence of zoledronate. The obtained results open the way of an easy transformation of currently existing HA-coated implants by grafting bisphosphonate onto the coating in order to increase their service life in the patients.

The effect of bisphosphonates and titanium particles on osteoblasts: an in vitro study.

In an attempt to increase the life of cementless prostheses, an hydroxyapatite-coated implant which releases a bisphosphonate has been suggested as a drug-delivery system. Our in vitro study was designed to determine the maximum dose to which osteoblasts could be safely exposed. Our findings demonstrated that zoledronate did not impair the proliferation of human osteoblasts when used at concentrations below 1 microm. Murine cells can be exposed to concentrations as high as 10 microm.A concentration of 0.01% of titanium particles did not impair the proliferation of either cell line. Zoledronate affected the alkaline phosphatase activity of murine osteoblasts through a chelation phenomenon. The presence of titanium particles strongly decreased the alkaline phosphatase activity of murine osteoblasts. We did not detect any synergic effect of zoledronate and titanium particles on the behaviour of both human and murine osteoblasts.

How plate positioning impacts the biomechanics of the open wedge tibial osteotomy; a finite element analysis.

A numerical model of the medial open wedge tibial osteotomy based on the finite element method was developed. Two plate positions were tested numerically. In a configuration, (a), the plate was fixed in a medial position and (b) in an anteromedial position. The simulation took into account soft tissues preload, muscular tonus and maximal gait load.The maximal stresses observed in the four structural elements (bone, plate, wedge, screws) of an osteotomy with plate in medial position were substantially higher (1.13-2.8 times more) than those observed in osteotomy with an anteromedial plate configuration. An important increase (1.71 times more) of the relative micromotions between the wedge and the bone was also observed. In order to avoid formation of fibrous tissue at the bone wedge interface, the osteotomy should be loaded under 18.8% (approximately 50 kg) of the normal gait load until the osteotomy interfaces union is achieved.

[Painful total hip arthroplasty]. / La prothèse de hanche douloureuse.

The results of the total hip prostheses in terms of cost-efficiency make one of the surgical procedures the most efficient. Usually, the articular pains disappear completely and the patient function improves. Outside, turned out failures, which require a revision, some patients present residual pain persisting after the intervention or appearing secondarily. Considering the important number of total hip arthroplasties, this clinical situation is not so rare and the generalist, as the specialist, can be confronted there. The experience shows that the surgical revisions, in the absence of a precise diagnosis are disappointing and often do not improve the patient. This article presents the diagnostic and therapeutic steps advised to face this problem.

Gentamicin-loaded hydraulic calcium phosphate bone cement as antibiotic delivery system.

A hydraulic calcium phosphate cement made of beta-tricalcium phosphate [beta-Ca3(PO4)2], monocalcium phosphate monohydrate [Ca(H2PO4)2-H2O], and water was used as a delivery system for the antibiotic gentamicin sulfate (GS). GS, added as powder or as aqueous solution, was very beneficial to the physicochemical properties of the cement. The setting time increased from 2 to 4.5 min with 3% (w/w) GS and then slowly decreased to 3.75 min with 16% (w/w) GS. The tensile strength increased from 0.4 to 1.6 MPa with 16% (w/w) GS. These effects were attributed to the presence of sulfate ions in GS. The release of GS from the cement was measured in a pH 7.4 phosphate-buffered saline solution at 37 degrees C by USP paddle method. Factors such as cement porosity, GS content and presence of sulfate ions or polymeric additives were investigated. The amount of GS released was roughly proportional to the square root of time up to approximately 50% release. Afterwards, the release rate markedly slowed down to zero. In all but two cement formulations, the total dose of GS was released within 7 days, indicating that no irreversible binding occurred between the cement paste and the antibiotic. When small amounts of hydroxypropylcellulose or poly(acrylic acid) were added to the cement, the maximum fraction released was a few percent lower than the total GS dose, suggesting some binding between the polymer and GS. The GS release rate was strongly influenced by the presence of sulfate ions in the cement paste and by the cement porosity. The higher the sulfate ion content of the cement paste, the lowe the GS release rate. This influence was attributed to the finer cement micro-structure induced by the presence of sulfate ions. Furthermore, when the initial cement porosity was increased from 38 to 69%, the release rate almost tripled (0.16 to 0.45 h-1/2). Finally, the biological activity of GS in the cement was maintained, as measured by assaying the release medium.

Peri-implant bone remodeling after total hip replacement combined with systemic alendronate treatment: a finite element analysis.

In order to decrease the peri-implant bone loss during the life-time of the implant, oral use of anti-osteoporosis drugs (like bisphosphonates) has been suggested. In this study, bone remodeling parameters identified from clinical trials of alendronate were used to simulate the effect of those drugs used after total hip arthroplasty on the peri-implant bone density. Results of the simulation show that the oral administrated drugs increase bone density around the implant and decreases, at the same time, the micromovements between the implant and the surrounding bone tissue. Incorporation of drug effect in numerical studies of bone remodeling is a promising tool especially to predetermine safe bisphosphonate doses that could be used with orthopedic implants.

Simplified 3D-evaluation of periacetabular osteotomy.

Reorientation osteotomies are widely used for the treatment of residual dysplasia of the hip. Preoperative planning is mandatory, and 3D-evaluation is of utmost importance for precise definition of direction and magnitude of displacement of the acetabulum. Instead of a 3D-CT scan reconstruction which needs multiple slices, we developed a 3D-reconstruction from a single AP pelvic view. This method is applicable if we accept that the femoral head and acetabulum are quite spherical. Appropriate software and a PC are used for this reconstruction that we compared with 3D CT-scan reconstruction and pelvic anatomical preparations. Twenty-two patients, 17 female, 5 male, with hip dysplasia, were treated by periacetabular osteotomy according to Ganz. The mean age was 27 years (14-40 years); the mean follow-up, 4.8 years (2-7 years). Four patients were treated conservatively in infancy for DDH, one patient had snapping hips associated with hip dysplasia, and two patients had slight sequellae of cerebral palsy. All patients were symptomatic mainly during daily activities or sports. The clinical evaluation was done using the Charnley scoring system. The Charnley score for pain improved from 3.6 (2-3.5) to 5.8 (5-6) at follow-up. No restriction of mobility or of walking capacity was observed after operation. The computer-assisted method also permits appreciation of the evolution of classical coxometry; i.e. Wiberg and Lequesne angles. The improvement after Ganz osteotomy was respectively 141% and 161% for Wiberg and Lequesne angles without any posterior uncoverage. The 3D-evaluation showed an improvement of 28% of the vertical projection area of the acetabulum on the femoral head. The anterolateral coverage improved from 20.3 to 50.1%. The Ganz osteotomy is really a 3D-reorientation osteotomy. With our simplified method it is possible to predict and control the amount of displacement to be done. However, we have to keep in mind that the articular cartilage is a limited crescent in the acetabulum; this method cannot replicate exactly the form and shape of articular cartilage. At this time it allows us to better control the amount of displacement during operation to avoid too large a displacement or lateralization.

[Clinical evaluation of total knee prosthesis: comparative analysis of scores]. / Evaluation clinique des prothèses totales du genou: analyse comparative des scores.

PURPOSE OF THE STUDY: Numerous scoring systems have been described for the evaluation of total knee arthroplasty. The aim of this study was to analyze the reality of the results and the differences between clinical evaluation scores. MATERIAL AND METHOD: We calculated the mean overall scores (Hungerford, Laskin, Hospital Special Surgery and Mansat) in a series of 89 PCA total knee arthroplasties with a mean follow-up of 4.5 years. We compared postoperative score values considered as borderline between poor and good results with survival curves. RESULTS: The mean values of the postoperative scores were very similar and showed no significant differences: Hungerford: 83 pts; Laskin: 80 pts; HSS: 80 pts; and Mansat: 86 pts. The comparison between the four survival curves was statistically significant: the Hungerford curve was the most optimistic (62 per cent success at 8 years) when compared to the Laskin score (16 per cent success at 8 years). DISCUSSION: The scores do not express the same reality. For mean values close or identical to the scores, the quality of the results may be different. Our analytic method reveals considerable differences explained by the juxtaposition of clinical and functional parameters in the scores. The Hungerford and Mansat scores are principally based on clinical criteria while the Laskin score is more functionally orientated. The HSS score is more even handed. CONCLUSION: It is incorrect to appreciate the value of survival curves if the scores are based on functional criteria as these parameters will naturally deteriorate over time and therefore these scores do not reflect the real quality of the arthroplasty. The Knee Society Score is probably the most interesting system since functional and clinical parameters are separated.

[Total knee prosthesis. Clinical and numerical study of micromovements of the tibial implant]. / Prothèses totales de genoux. Analyse clinique et numérique des micromouvements de l'implant tibial.

INTRODUCTION: The importance of the micromovements in the mechanism of aseptic loosening is clinically difficult to evaluate. To complete the analysis of a series of total knee arthroplasties (TKA), we used a tridimensional numerical model to study the micromovements of the tibial implant. MATERIAL AND METHODS: Fifty one patients (with 57 cemented Porous Coated Anatomic TKAs) were reviewed (mean follow-up 4.5 year). Radiolucency at the tibial bone-cement interface was sought on the AP radiographs and divided in 7 areas. The distribution of the radiolucency was then correlated with the axis of the lower limb as measured on the orthoradiograms. The tridimensional numerical model is based on the finite element method. It allowed the measurement of the cemented prosthetic tibial implant's displacements and the micromovements generated at bone-ciment interface. A total load (2000 Newton) was applied at first vertically and asymetrically on the tibial plateau, thereby simulating an axial deviation of the lower limbs. The vector's posterior inclination then permitted the addition of a tangential component to the axial load. This type of effort is generated by complex biomechanical phenomena such as knee flexion. RESULTS: 81 per cent of the 57 knees had a radiolucent line of at least 1 mm, at one or more of the tibial cement-epiphysis jonctional areas. The distribution of these lucent lines showed that they came out more frequently at the periphery of the implant. The lucent lines appeared most often under the unloaded margin of the tibial plateau, when axial deviation of lower limbs was present. Numerical simulations showed that asymetrical loading on the tibial plateau induced a subsidence of the loaded margin (0-100 microns) and lifting off at the opposite border (0-70 microns). The postero-anterior tangential component induced an anterior displacement of the tibial implant (160-220 microns), and horizontal micromovements with non homogenous distribution at the bone-ciment interface (28-54 microns). DISCUSSION: Comparison of clinical and numerical results showed a relation between the development of radiolucent lines and the unloading of the tibial implant's margin. The deleterious effect of lower limbs' axial deviation is thereby proven. The irregular distribution of lucent lines under the tibial plateau was similar of the micromovements' repartition at the bone-cement interface when tangential forces were present. A causative relation between the two phenomenaes could not however be established. Numerical simulation is a truly useful method of study; it permits to calculate micromovements which are relative, non homogenous and of very low amplitude. However, comparative clinical studies remain as essential to ensure the credibility of results.

[Knee joint endoprostheses]. / Endoprothesen am Kniegelenk.

The story of the total knee arthroplasty begins in the last century. But in 1971, Gunston shows the way of the modern knee arthroplasty and creates the concept of unconstrained arthroplasty. The indication of the total knee arthroplasty should be precise and rigorous. It's not possible to describe all the situations, where a total knee arthroplasty is indicated or not, but the clinical signs could be summarized in pain, stiffness, deformation with or without instability. We observed 10% of postoperative complications; most of them are secondary, but the infections and loosening remain the principal problem in 2% and in 5% of cases, respectively. If the results are now quite the same to those of total hip arthroscopy by survivorship analysis, the indication and the choice of the total knee prosthesis should be passed on a reflection, where the clinical and functional evaluation are the most important.

Spatio-temporal gait analysis in children with cerebral palsy using, foot-worn inertial sensors.

A child's natural gait pattern may be affected by the gait laboratory environment. Wearable devices using body-worn sensors have been developed for gait analysis. The purpose of this study was to validate and explore the use of foot-worn inertial sensors for the measurement of selected spatio-temporal parameters, based on the 3D foot trajectory, in independently walking children with cerebral palsy (CP). We performed a case control study with 14 children with CP aged 6-15 years old and 15 age-matched controls. Accuracy and precision of the foot-worn device were measured using an optical motion capture system as the reference system. Mean accuracy ± precision for both groups was 3.4 ± 4.6 cm for stride length, 4.3 ± 4.2 cm/s for speed and 0.5 ± 2.9° for strike angle. Longer stance and shorter swing phases with an increase in double support were observed in children with CP (p=0.001). Stride length, speed and peak angular velocity during swing were decreased in paretic limbs, with significant differences in strike and lift-off angles. Children with cerebral palsy showed significantly higher inter-stride variability (measured by their coefficient of variation) for speed, stride length, swing and stance. During turning trajectories speed and stride length decreased significantly (p<0.01) for both groups, whereas stance increased significantly (p<0.01) in CP children only. Foot-worn inertial sensors allowed us to analyze gait spatiotemporal data outside a laboratory environment with good accuracy and precision and congruent results with what is known of gait variations during linear walking in children with CP.

Augmentation of bone defect healing using a new biocomposite scaffold: an in vivo study in sheep.

Previous studies support resorbable biocomposites made of poly(L-lactic acid) (PLA) and beta-tricalcium phosphate (TCP) produced by supercritical gas foaming as a suitable scaffold for tissue engineering. The present study was undertaken to demonstrate the biocompatibility and osteoconductive properties of such a scaffold in a large animal cancellous bone model. The biocomposite (PLA/TCP) was compared with a currently used beta-TCP bone substitute (ChronOS, Dr. Robert Mathys Foundation), representing a positive control, and empty defects, representing a negative control. Ten defects were created in sheep cancellous bone, three in the distal femur and two in the proximal tibia of each hind limb, with diameters of 5 mm and depths of 15 mm. New bone in-growth (osteoconductivity) and biocompatibility were evaluated using microcomputed tomography and histology at 2, 4 and 12 months after surgery. The in vivo study was validated by the positive control (good bone formation with ChronOS) and the negative control (no healing with the empty defect). A major finding of this study was incorporation of the biocomposite in bone after 12 months. Bone in-growth was observed in the biocomposite scaffold, including its central part. Despite initial fibrous tissue formation observed at 2 and 4 months, but not at 12 months, this initial fibrous tissue does not preclude long-term application of the biocomposite, as demonstrated by its osteointegration after 12 months, as well as the absence of chronic or long-term inflammation at this time point.

[Dorso-lumbar spinal compression fractures in the child. Follow-up at the termination of development]. / Les fractures du rachis dorso-lombaire par compression chez l'enfant. Revue en fin de croissance.

Between 1970 and 1985, we count 32 children with compressive fractures of the vertebral column. None of them undergo a surgical procedure. We examine 24 of these 32 children with a mean delay of 10.5 years. Most of the fractures were referring to sporting activities and home games. The main localization was dorsal (T6) and upper-lumbar (12). The mean reduced height of the ventral portion of the vertebra was 27%. Some 10 years later, two third of the patients have some persistent pains and half of them daily. Most of the aches concerned children of more than 12 years when trauma occurred and those who developed a scoliosis during evolution. Wonder the global static of the rachis is little concerned in most of these children. Therefore compressive vertebral fracture of the youngster should be reduced and fixed by a corset. But the immobilization shouldn't be longer than 2 months, accompanied by appropriate gymnastics and followed by a quick renewal of the sporting activities.