Stéphane Descamps

Mesenchymal content of fresh bone marrow: a proposed quality control method for cell therapy.

The scarcity of mesenchymal stem cells (MSC) in bone marrow (BM) has justified their ex vivo expansion before therapeutic use, but a method to evaluate the quality of initial mesenchymal content and track the modifications induced by graft processing has not yet been proposed. The aim of this study was to establish such a procedure. Flow cytometric and functional assay methods were modified to count CD45− CD14−/CD73+ subsets containing all MSC and used them to study BM from spongy bone (SB) and iliac crest aspirate (ICA). These methods detected the target subsets in all BM suspensions derived from SB (n = 154) and ICA, (n = 44) with a satisfactory correlation between immuno‐phenotyping and functional tests by low‐density plating. We noted a higher overall MSC frequency in SB cell suspensions but a lower plating efficiency of CD45− CD14−/CD73+ SB cells under standard culture conditions.

Determinants of satisfaction 1 year after total hip arthroplasty: the role of expectations fulfilment

BackgroundBetween 7% and 15% of patients are dissatisfied after total hip arthroplasty (THA). To assess predictors and postoperative determinants of satisfaction and expectation fulfilment one year after (THA).MethodsBefore THA surgery, 132 patients from three tertiary care centres and their surgeons were interviewed to assess their expectations using the Hospital for Special Surgery Total Hip Replacement Expectations Survey (THR survey). One year after surgery, patients (n = 123) were contacted by phone to complete a questionnaire on expectation fulfilment (THR survey), satisfaction, functional outcome (Womac), and health-related quality of life (SF 12). Univariate and multivariate analyses were performed.ResultsPreoperative predictors of satisfaction were a good mental wellbeing (adjusted OR 1.09 [1.02; 1.16], p = 0.01) and optimistic surgeons expectations (1.07 [1.01; 1.14], p = 0.02). The main postoperative determinant of satisfaction was the fulfilment of patient’s expectations (1.08 [1.04; 1.12], p < 0.001). Expectation fulfilment could be predicted before surgery by young age (regression coefficient −0.55 [−0.88; -0.21], p = 0.002), good physical function (−0.96 [−1.82; -0.10], p = 0.03) and good mental wellbeing (0.56 [0.14; 0.99], p = 0.01). Postoperative determinants of expectation fulfilment were functional outcome (−2.10 [−2.79; -1.42], p <0.001) and pain relief (−14.83 [−22.38; -7.29], p < 0.001).ConclusionTo improve patient satisfaction after THA, patients’ expectations and their fulfilment need to be carefully addressed. Patients with low mental wellbeing or physical function should be identified and specifically informed on expected surgical outcome. Surgeons’ expectations are predictive of satisfaction and information should aim to lower discrepancy between surgeons’ and patients’ expectations.

Complex primary total hip arthroplasty.

Although total hip arthroplasty is now a classic procedure that is well controlled by orthopedic surgeons, some cases remain complex. Difficulties may be due to co-morbidities: obesity, skin problems, muscular problems, a history of neurological disease or associated morphological bone deformities. Obese patients must be informed of their specific risks and a surgical approach must be used that obtains maximum exposure. Healing of incisions is not a particular problem, but adhesions must be assessed. Neurological diseases may require tenotomy and the use of implants that limit instability. Specific techniques or implants are necessary to respect hip biomechanics (offset, neck-shaft angle) in case of a large lever arm or coxa vara. In case of arthrodesis, before THA can be performed, the risk of infection must be specifically evaluated if the etiology is infection, and the strength of the gluteal muscles must be determined. Congenital hip dysplasia presents three problems: the position and coverage of the cup, placement of a specific or custom made femoral stem, with an osteotomy if necessary, and finally lowering the femoral head into the cup by freeing the soft tissues or a shortening osteotomy. Acetabular dysplasia should not be underestimated in the presence of significant bone defect (BD), and reconstruction with a bone graft can be proposed. Sequelae from acetabular fractures presents a problem of associated BD. Internal fixation hardware is rarely an obstacle but the surgical approach should take this into account. Treatment of acetabular protrusio should restore a normal center of rotation, and prevent recurrent progressive protrusion. The use of bone grafts and reinforcement rings are indispensible. Femoral deformities may be congenital or secondary to trauma or osteotomy. They must be evaluated to restore hip biomechanics that are as close to normal as possible. Fixation of implants should restore anteversion, length and the lever arm. Most problems that can make THA a difficult procedure may be anticipated with proper understanding of the case and thorough preoperative planning.

Photoactive TiO2 antibacterial coating on surgical external fixation pins for clinical application

External fixation is a method of osteosynthesis currently used in traumatology and orthopedic surgery. Pin tract infection is a common problem in clinical practice. Infection occurs after bacterial colonization of the pin due to its contact with skin and the local environment. One way to prevent such local contamination is to create a specific coating that could be applied in the medical field. In this work, we developed a surface coating for external fixator pins based on the photocatalytic properties of titanium dioxide, producing a bactericidal effect with sufficient mechanical strength to be compatible with surgical use. The morphology and structure of the sol-gel coating layers were characterized using, respectively, scanning electron microscopy and X-ray diffraction. The resistance properties of the coating were investigated by mechanical testing. Photodegradation of acid orange 7 in aqueous solution was used as a probe to assess the photocatalytic activity of the titanium dioxide layers under ultraviolet irradiation. The bactericidal effect induced by the process was evaluated against two strains, ie, Staphylococcus aureus and multiresistant Staphylococcus epidermidis. The coated pins showed good mechanical strength and an efficient antibacterial effect after 1 hour of ultraviolet irradiation.

Cu‐doping of calcium phosphate bioceramics: From mechanism to the control of cytotoxicity

In this study, the Cu-doping mechanism of Biphasic Calcium Phosphate (BCP) was thoroughly investigated, as was its ionic release behavior, in order to elucidate cytotoxicity features of these bioceramics. BCP are composed of hydroxyapatite (Ca10(PO4)6(OH)2) and β-TCP (Ca3(PO4)2). The two phases present two different doping mechanisms. Incorporation into the β-TCP structure is achieved at around 700 °C thanks to a substitution mechanism leading to the Cu-doped Ca3-xCux(PO4)2 compound. Incorporation into the HAp structure is achieved thanks to an interstitial mechanism that is limited to a Cu-poor HAp phase for temperatures below 1100 °C (Ca10Cux(PO4)6(OH)2-2xO2x with x < 0.1). Above 1100 °C, the same interstitial mechanism leads to the formation of a Cu-rich HAp mixed-valence phase (Ca10Cu2+xCu+y(PO4)6(OH)2-2x-yO2x+y with x + y ∼ 0.5). The formation of both high-temperature Cu-doped α-TCP and Cu3(PO4)2 phases above 1100 °C induces a transformation into the Cu-rich HAp phase on cooling. The linear OCuO oxocuprate entity was confirmed by EXAFS spectroscopy, and the mixed Cu+/Cu2+ valence was evidenced by XPS analyses. Ionic releases (Cu+/Cu2+, Ca2+, PO42- and OH-) in water and in simulated body media were investigated on as-synthesized ceramics to establish a pretreatment before biological applications. Finally the cytotoxicity of pretreated disks was evaluated, and results confirm that Cu-doped BCP samples are promising bioceramics for bone substitutes and/or prosthesis coatings. STATEMENT OF SIGNIFICANCE Biphasic Calcium Phosphates (BCP) are bioceramics composed of hydroxyapatite (HAp, Ca10(PO4)6(OH)2) and beta-Tricalium Phosphate (β-TCP, Ca3(PO4)2). Because their chemical and mineral composition closely resembles that of the mineral component of bone, they are potentially interesting candidates for bone repair surgery. Doping can advantageously be used to improve their biological behaviors; however, it is important to describe the doping mechanism of BCP thoroughly in order to fully appraise the benefit of the doping process. The present paper scrutinizes in detail the incorporation of copper cation in order to correctly interpret the behavior of the Cu-doped bioceramic in biological fluid. The understanding of the copper doping mechanism, related to doping mechanism of others 3d-metal cations, makes it possible to explain the rates and kinetic of release of the dopant in biological medium. Finally, the knowledge of the behavior of the copper doped ceramic in biological environment allowed the tuning of its cytotoxicity properties. The present study resulted on pre-treated ceramic disks which have been evaluated as promising biocompatible ceramic for bone substitute and/or prosthesis coating: good adherence of bone marrow cells with good cell viability.

Transcultural validation of the Risk Assessment and Predictor Tool (RAPT) to predict discharge outcomes after total hip replacement

OBJECTIVE To assess the relevance of the RAPT (Risk Assessment and Prediction Tool), among a cohort of patients undergoing total hip arthroplasty (THA). METHOD Prospective study of a cohort of patients evaluated before and after THA. The difference between the postoperative orientation predicted by the RAPT and the real one is assessed. Clinical, environmental and psychosocial criteria that could significantly change the orientation are discussed. RESULTS One hundred and thirty-four patients (94 women and 40 men) were included. The average age was 71.6 (±10) years. Primary hip osteoarthritis was the indication for surgery in 78% of cases. The average length of stay in the surgery ward was 10 (±3) days. It was significantly higher for patients referred to a rehabilitation ward (P<0.0001). Sixty-six percent of patients were referred to a rehabilitation ward and 34% returned directly home. The average length of stay in rehabilitation ward was 27 (±13) days. The validity of the RAPT as a help decision tool has been confirmed. Thus, a low RAPT score was significantly associated with more frequent referral to a rehabilitation ward, conversely, a high RAPT score is significantly related to more frequent direct return to home. CONCLUSION This study confirmed the usefulness of the RAPT to help in patient orientation decision after total hip arthroplasty. The patient preference remains the main variable for orientation after THA. By the way, the patient preference must not be integrated into the RAPT, but need to be collected and be discussed with the patient.

Synostose scaphotrapézienne congénitale bilatérale

Congenital synostosis has been described between nearly all of the carpal bones. It can occur in an isolated form or most commonly in relation between the lunatum and the triquetrum. It can also occur in a multiple form and be associated with other malformations. We report a rare case of scaphoid-trapezium fusion observed bilaterally in a nearly asymptomatic 63-year-old patient.

Randomized blinded trial of standardized written patient information before total knee arthroplasty

Background The effect of patient education before total knee arthroplasty (TKA) is controversial. No consensus exists about the optimal content of educational interventions. In a previous study, we developed and validated an educational booklet on the peri-TKA management of knee osteoarthritis. Purposes Our primary purpose was to evaluate the impact of the educational booklet on knowledge among patients awaiting TKA. Patients and methods This randomized controlled single-blind trial evaluated standard information by the surgeon with or without delivery of the educational booklet 4–6 weeks before primary noncomplex TKA in patients aged 55–75 years with incapacitating knee osteoarthritis. Patients were enrolled at a French surgical center between June 2011 and January 2012. A patient knowledge score was determined at baseline, on the day before TKA, and 3–6 weeks after TKA, using a self-administered questionnaire developed for our previous study. The assessor was blinded to group assignment. Results Of 44 eligible patients, 42 were randomized, 22 to the intervention and 20 to the control group, all of whom were included in the analysis. The groups were comparable at baseline. The intervention was associated with significantly better patient knowledge scores. Conclusions An educational booklet improves knowledge among patients awaiting TKA. A study assessing the impact of the booklet combined with a exercise program would be helpful. Level of evidence Level I, randomized controlled double-blind trial; see S1 CONSORT Checklist. Trial registration clinicaltrials.gov #NCT01747759

Opening-wedge high tibial osteotomy with a secure bone allograft (Osteopure™) and locked plate fixation: Retrospective clinical and radiological evaluation of 69 knees after 7.5 years follow-up

BACKGROUND Medial opening-wedge high tibial osteotomy (OWHTO) provides reliable and long-lasting benefits, despite the wide range of wedge-filling and internal-fixation techniques used. The purpose of this work was to assess the clinical and radiological outcomes in a case-series of OWHTO performed using a secure bone allograft and locked plate fixation. HYPOTHESIS The clinical and radiological outcomes of OWHTO with a high-safety bone allograft and locked plate fixation are similar to those reported in previous case-series studies. MATERIALS AND METHODS A single-centre retrospective design was used to study 69 knees in 64 patients with a mean age of 51.8years (31-53years) and a preoperative hip-knee-ankle (HKA) angle of 173° (165°-180°). The wedge was filled with secure Osteopure™ bone allograft and fixation was achieved using an Integra Surfix(®) locked plate. Mean follow-up was 7.5years (5-9.3years). Clinical and functional outcomes were assessed by determining the IKS and KOOS-PS scores and recording complications related or unrelated to the allograft. The main criterion for assessing OWHTO survival was the time to revision surgery for symptom recurrence. Radiological assessment criteria were the HKA angle, tibial slope, patellar height, and osteoarthritis grade. GESTO criteria were used to evaluate the behaviour of the allograft. RESULTS Of the 69 knees, 64 (92.8%) were re-evaluated. The survival rate after 9.3years was 95%±2.7% (3 failures managed with arthroplasty). The functional IKS score improved significantly, by 20 points (P<0.001). Mean increases of 7.8° for the HKA angle and 3.5° for tibial slope were recorded. Bone healing without radiological abnormalities was consistently achieved within 6months. There were no complications related to the allograft (infections, allergies; local or systemic toxicity). DISCUSSION The clinical, radiological, and safety outcomes documented in our study were similar to those reported in earlier work. LEVEL OF EVIDENCE IV, retrospective case-series study.

Radiographic stereometry for non-metal-backed acetubular cups: 3D wear estimation and related uncertainty

The aim of this work was to assess the 3D wear of non-metal-backed acetubular cups from two conventional digitized radiographs. The centers of the femoral head and the metal ring in the equatorial plane of the cup are located using 3D pose techniques for spheres and circles from sampled points in the images. The method used to locate these points of interest and also estimate their covariance is fully described in previous work. The covariance is used to decrease the bias of the pose estimation, while bootstrapping decreases its variance and gives access to the directions of minimal variability between the two centers for each image. These directions are used to produce the final distance after reconstruction. Results are compared with the 2D technique working on a single anteroposterior (AP) radiograph and assuming null lateral wear. Validation is performed on acetubular cups: (a) simulated by Monte-Carlo, (b) implanted on a pelvic model, and (c) acquired on patients just after arthroplasty. The accuracy in wear for simulation increases from about one to four hundredths of a millimeter as caudal and cranial absolute angulations decreases from 45 degrees to 30 degrees . It is more difficult to assess for real prostheses, but results are shown to lie within the manufacturers dimensional tolerances. Globally, the access to the lateral wear is obtained at the expense of confidence in the global linear wear (0.06 mm), which is doubled with regard to 2D technique but still satisfying for clinical use, whereas the bias of the measurement is decreased.