Simultaneous Evaluation of Bone Cut and Implant Placement Accuracy in Robotic-Assisted Total Knee Arthroplasty.

Background: This study aimed to evaluate the accuracy of bone cuts and implant placements, simultaneously, for total knee arthroplasty (TKA) performed using a system with an active robotic arm. Methods: Two experienced orthopaedic surgeons performed TKA on ten cadaveric legs. Computed tomography scans were performed to compare the bone cuts and implant placements with the preoperative planning. The differences between the planned and actual bone cuts and implant placements were assessed using positional and angular errors in the three anatomical planes. Additionally, the cut-implant deviations were calculated. Statistical analysis was performed to detect systematic errors in the bone cuts and implant placements and to quantify the correlations between these errors. Results: The root-mean-square (RMS) errors of the bone cuts (with respect to the planning) were between 0.7-1.5 mm and 0.6-1.7°. The RMS implant placement errors (with respect to the planning) varied between 0.6-1.6 mm and 0.4-1.5°, except for the femur and tibia in the sagittal plane (2.9°). Systematic errors in the bone cuts and implant placements were observed, respectively, in three and two degrees of freedom. For cut-implant deviations, the RMS values ranged between 0.3-2.0 mm and 0.6-1.9°. The bone cut and implant placement errors were significantly correlated in eight degrees-of-freedom (ρ ≥ 0.67, p < 0.05). Conclusions: With most of the errors below 2 mm or 2°, this study supported the value of active robotic TKA in achieving accurate bone cuts and implant placements. The findings also highlighted the need for both accurate bone cuts and proper implantation technique to achieve accurate implant placements.

An Expert-Supervised Registration Method for Multiparameter Description of the Knee Joint Using Serial Imaging.

As knee osteoarthritis is a disease of the entire joint, our pathophysiological understanding could be improved by the characterization of the relationships among the knee components. Diverse quantitative parameters can be characterized using magnetic resonance imaging (MRI) and computed tomography (CT). However, a lack of methods for the coordinated measurement of multiple parameters hinders global analyses. This study aimed to design an expert-supervised registration method to facilitate multiparameter description using complementary image sets obtained by serial imaging. The method is based on three-dimensional tissue models positioned in the image sets of interest using manually placed attraction points. Two datasets, with 10 knees CT-scanned twice and 10 knees imaged by CT and MRI were used to assess the method when registering the distal femur and proximal tibia. The median interoperator registration errors, quantified using the mean absolute distance and Dice index, were ≤0.45 mm and ≥0.96 unit, respectively. These values differed by less than 0.1 mm and 0.005 units compared to the errors obtained with gold standard methods. In conclusion, an expert-supervised registration method was introduced. Its capacity to register the distal femur and proximal tibia supports further developments for multiparameter description of healthy and osteoarthritic knee joints, among other applications.

Bone Cuts Accuracy of a System for Total Knee Arthroplasty including an Active Robotic Arm.

INTRODUCTION: This study aimed to assess the bone cuts accuracy of a system for total knee arthroplasty including an active robotic arm. A second objective was to compare the accuracy among orthopaedic surgeons of different levels of experience. METHODS: Three orthopaedic surgeons cut 10 sawbone knees each. Planned and actual bone cuts were compared using computed tomography. Difference with respect to the planning was expressed as three position and three orientation errors following the anatomical planes. Statistical tests were performed to detect bias and compare surgeons. RESULTS: None of the 30 knees presented an outlier error, meaning an error ≥3 mm or ≥3°. The root-mean-square values of the 12 error types were below 0.8 mm or 0.8°, except for the femoral proximal-distal errors (1.7 mm) and the tibial anterior-posterior errors (1.4 mm). Biases were observed, particularly in femoral proximal-distal and tibial anterior-posterior positions. Median differences between surgeons were all lower than 0.8 mm and 0.5°, with statistically significant differences among surgeons in the femoral proximal-distal errors and the tibial anterior-posterior errors. CONCLUSIONS: The system tested in this study achieved accurate bone cuts independently of the surgeon's level of experience. Biases were observed, suggesting that there might be options to improve the accuracy, particularly in proximal-distal position for the femur and in anterior-posterior position for the tibia.

[Enhanced recovery after prosthetic surgery]. / Réhabilitation améliorée après chirurgie prothétique.

The enhanced recovery after surgery (ERAS) is a proven concept in many surgical disciplines since the early 2000s. Studies agree benefit in prosthetic surgery and it has been shown to lead to improved practices and results permitting a faster discharge to home with lesser morbidity and mortality. It implies a cohesion in the message delivery and the general practitioner plays a central role. The collection and analysis of the data is fundamental to continuously improve the protocol and thus the care of patients. These protocols are a step towards outpatient management in this kind of surgery.

La réhabilitation améliorée après chirurgie est un concept qui a déjà fait ses preuves dans de nombreuses disciplines chirurgicales depuis le début des années 2000. Les études s'accordent sur son intérêt en chirurgie prothétique et il a été prouvé qu'elle entraîne une amélioration des pratiques et des résultats permettant un retour à domicile plus rapide, avec une diminution de la morbidité et mortalité. Elle implique une cohésion dans la délivrance du message et le médecin généraliste garde une place centrale. Le recueil et l'analyse des résultats sont fondamentaux pour améliorer continuellement le protocole et ainsi la prise en charge des patients. Ces protocoles sont une étape vers la prise en charge ambulatoire de ce type de chirurgie.

Early efficacy evaluation of mesenchymal stromal cells (MSC) combined to biomaterials to treat long bone non-unions.

BACKGROUND AND STUDY AIM: Advanced therapy medicinal products (ATMP) frequently lack of clinical data on efficacy to substantiate a future clinical use. This study aims to evaluate the efficacy to heal long bone delayed unions and non-unions, as secondary objective of the EudraCT 2011-005441-13 clinical trial, through clinical and radiological bone consolidation at 3, 6 and 12 months of follow-up, with subgroup analysis of affected bone, gender, tobacco use, and time since the original fracture. PATIENTS AND METHODS: Twenty-eight patients were recruited and surgically treated with autologous bone marrow derived mesenchymal stromal cells expanded under Good Manufacturing Practices, combined to bioceramics in the surgical room before implantation. Mean age was 39 ± 13 years, 57% were males, and mean Body Mass Index 27 ± 7. Thirteen (46%) were active smokers. There were 11 femoral, 4 humeral, and 13 tibial non-unions. Initial fracture occurred at a mean ± SD of 27.9 ± 31.2 months before recruitment. Efficacy results were expressed by clinical consolidation (no or mild pain if values under 30 in VAS scale), and by radiological consolidation with a REBORNE score over 11/16 points (value of or above 0.6875). Means were statistically compared and mixed models for repeated measurements estimated the mean and confidence intervals (95%) of the REBORNE Bone Healing scale. Clinical and radiological consolidation were analyzed in the subgroups with Spearman correlation tests (adjusted by Bonferroni). RESULTS: Clinical consolidation was earlier confirmed, while radiological consolidation at 3 months was 25.0% (7/28 cases), at 6 months 67.8% (19/28 cases), and at 12 months, 92.8% (26/28 cases including the drop-out extrapolation of two failures). Bone biopsies confirmed bone formation surrounding the bioceramic granules. All locations showed similar consolidation, although this was delayed in tibial non-unions. No significant gender difference was found in 12-month consolidation (95% confidence). Higher consolidation scale values were seen in non-smoking patients at 6 (p = 0.012, t-test) and 12 months (p = 0.011, t-test). Longer time elapsed after the initial fracture did not preclude the occurrence of consolidation. CONCLUSION: Bone consolidation was efficaciously obtained with the studied expanded hBM-MSCs combined to biomaterials, by clinical and radiological evaluation, and confirmed by bone biopsies, with lower consolidation scores in smokers.

Feasibility and safety of treating non-unions in tibia, femur and humerus with autologous, expanded, bone marrow-derived mesenchymal stromal cells associated with biphasic calcium phosphate biomaterials in a multicentric, non-comparative trial.

BACKGROUND: ORTHO-1 is a European, multicentric, first in human clinical trial to prove safety and feasibility after surgical implantation of commercially available biphasic calcium phosphate bioceramic granules associated during surgery with autologous mesenchymal stromal cells expanded from bone marrow (BM-hMSC) under good manufacturing practices, in patients with long bone pseudarthrosis. METHODS: Twenty-eight patients with femur, tibia or humerus diaphyseal or metaphyso-diaphyseal non-unions were recruited and surgically treated in France, Germany, Italy and Spain with 100 or 200 million BM-hMSC/mL associated with 5-10 cc of bioceramic granules. Patients were followed up during one year. The investigational advanced therapy medicinal product (ATMP) was expanded under the same protocol in all four countries, and approved by each National Competent Authority. FINDINGS: With safety as primary end-point, no severe adverse event was reported as related to the BM-hMSC. With feasibility as secondary end-point, the participating production centres manufactured the BM-hMSC as planned. The ATMP combined to the bioceramic was surgically delivered to the non-unions, and 26/28 treated patients were found radiologically healed at one year (3 out of 4 cortices with bone bridging). INTERPRETATION: Safety and feasibility were clinically proven for surgical implantation of expanded autologous BM-hMSC with bioceramic. FUNDING: EU-FP7-HEALTH-2009, REBORNE Project (GA: 241876).

Comparative bone tissue integration of nanostructured and microroughened dental implants.

AIM: The aim was to compare osteointegration of nanostructured implants to a microsurface widely used for titanium dental implants. MATERIALS & METHODS: Commercial titanium dental implants with smooth or microroughened surfaces were nanostructured. Implants were inserted into the femoral condyles of rabbits. After 2 and 4 weeks, histomorphometry calculation was performed. RESULTS: Nanotubes measuring 60 nm in diameter were observed on both S-NANO (roughness: 0.05 µm) and R-NANO (roughness: 0.40 µm) surfaces. The MICRO surface exhibited typical random cavities (roughness: 2.09 µm). At 4 weeks, bone-to-implant contact values were significantly higher for the R-NANO than for the MICRO surface while no differences were observed at 2 weeks. CONCLUSION: Overall, this study shows that the nanostructured surfaces improved osteointegration similar or higher than the MICRO.

Bone fracture healing: cell therapy in delayed unions and nonunions.

Bone fracture healing impairment related to mechanical problems has been largely corrected by advances in fracture management. Better protocols, more strict controls of time and function, and hardware and surgical technique evolution have contributed to better prognosis, even in complex fractures. However, atrophic nonunion persists in clinical cases where, for different reasons, the osteogenic capability is impaired. When this is the case, a better understanding of the basic mechanisms under bone repair and augmentation techniques may put in perspective the current possibilities and future opportunities. Among those, cell therapy particularly aims to correct this insufficient osteogenesis. However, the launching of safe and efficacious cell therapies still requires substantial amount of research, especially clinical trials. This review will envisage the current clinical trials on bone healing augmentation based on cell therapy, with the experience provided by the REBORNE Project, and the insight from investigator-driven clinical trials on advanced therapies towards the future. This article is part of a Special Issue entitled Stem Cells and Bone.

Percutaneous grafting with bone marrow autologous concentrate for open tibia fractures: analysis of forty three cases and literature review.

PURPOSE: Tibial fractures are the most common lower limb fractures. Some criteria such as open fractures and increasing open stage are known to be associated with high delayed union and pseudarthrosis rate. In cases of delayed or nonunion, classical treatment is autologous cancelous bone graft which is associated with high morbidity rate. The ideal treatment would be a percutaneous harvesting and grafting technique. As bone marrow autologous concentrate (BMAC) presents both advantages, we evaluated this technique from 2002 to 2007. METHODS: This was a retrospective study of 43 cases of open tibial fractures with initial surgical treatment. The criteria of inclusion were open fracture and nonunion, delayed union or suspicion of delayed union. RESULTS: In 23 cases (53.5 %) BMAC was successful. The success group had received significantly more CFU-F than the failure group (469 vs 153.10(3), p = 0.013). A threshold of 360.10(3) CFU-F grafted could be established over which there was 100 % success. BMAC done before 110 days after fracture had 47 % success and BMAC done since 110 days after fracture had 73 % success. BMAC success rate decreased with increasing initial fracture skin open stage. There was no BMAC success in cases of a fracture with a remaining gap of more than 4 mm. We had no complications with the technique at the iliac harvesting zone and tibia injection point. CONCLUSION: BMAC is a technique that should be considered as one of the different alternatives for management of long-bone delayed and nonunion because of its effectiveness, low complication rate, preservation of bone stock and low cost.