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

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

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

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

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

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. 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. 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. 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

Shoulder stabilization by modified Latarjet-Patte procedure: Results at a minimum 10years’ follow-up, and role in the prevention of osteoarthritis

AbstractIntroductionIn 1995, our team modified the Latarjet-Patte procedure by associating “south-north” capsule retention with reinsertion to the edge of the glenoid cavity to the coracoid bone-block.HypothesisThe present minimum 10-year follow-up study tested the hypothesis that the rate of osteoarthritis could be reduced by the strictly extra-articular position of the bone-block and stability be enhanced by the associated Bankart effect.Material and methodBetween January 1995 and December 2001, 78 shoulders were stabilized using the modified Latarjet-Patte procedure in 76 patients with a mean age at surgery of 26.7years; 89.7% could be followed up, 82.8% of whom also had radiographic follow-up. Fifty-nine were sports players, including 25 at competition level. Stability was assessed on a questionnaire, any dislocation or subluxation being counted as recurrence.ResultsAt a mean 13years’ follow-up (range, 10–15years), there had been no revision surgery. Mean Duplay score was 82.6, mean Subjective Shoulder Value 91.9% and the satisfaction rate 98.5%. The recurrence rate was 1.4% and 10 patients reported residual apprehension. The osteoarthritis rate was 8.5%. Seven bone-blocks projected, but only one was associated with osteoarthritis (stage 1) (non-significant). There were 4 non-unions and 9 lyses, without instability or pain.DiscussionThe modified procedure provided a low rate of recurrence and an incidence of osteoarthritis (8.5%) much lower than in any other published series with a minimum 10years’ follow-up. The strictly extra-capsular situation of the bone-block appeared as an important factor in limiting long-term osteoarthritis. Capsule reinsertion also seemed to alleviate the radiologic complications.Level of evidenceIV, retrospective study

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