Biomechanics and Impact Mechanics Laboratory

International audience

International audience

The aim of this study was to compare the long-term clinical and radiological results between fixed (FB) and mobile bearing (MB) implants with identical design from the same manufacturer. From March 2007 to May 2009, we recruited 160 patients in a prospective, single centered, randomized controlled trial. The authors compared 81 FB total knee arthroplasty (TKA) versus 79MB with medial compartment osteoarthritis. The same posterior stabilized HLS Noetos knee prosthesis (CORIN) was used in all patients. The two groups only differed by the tibial insert (fixed or mobile). The authors compared the postoperative Knee Society Score (KSS), the passive clinical and active radiological knee flexion, the implant survivorship, the complications, and the presence of radiolucent lines. At mean 10.5years' follow-up (range 8-12.1years) no significant differences were found in clinical scores (KSS (p = 0.54), pain score (p = 0.77), stair climbing (p = 0.44), passive maximum flexion (p = 0.5)) or for radiological analyses (maximum active radiological flexion (p = 0.06), presence of progressive radiolucent lines (5 (MB group) versus 6 (FB group); p = 0.75)) between groups. No significant difference was found in overall implant survivorship (82% (MB group) versus 78% (FB group) p = 0.58) or complication rate (p = 0.32) at the last follow-up. No significant clinical and radiological differences were found between fixed and mobile bearing TKA using the same semi-constrained implant type with comparable overall survivorship. The choice between a fixed or mobile bearing implant should be based on surgeon preference and experience with the selected implant. Prospective randomized controlled trial, Level II.

Tranexamic acid (TA) use in lower‑limb arthroplasty has been valued in these surgeries high‑risk hemorrhagic due to its antifibrinolytic action. The objective of the present study was to determine the effectiveness of the combined intravenous (IV) and intraarticular (IA) administration of TA in lower‑limb arthroplasty. We conduct a prospective observational study between January 1, 2014, and December 31, 2017, including all programmed lower‑limb arthroplasties. Patients were divided into four groups: no TA, 15mg/kg IV TA, 3g IA TA, and 15mg/kg IV and 3g IA. The effect on calculated total blood loss (milliliter of red blood cell [RBC]), hemoglobin, transfusion, and duration of hospitalization was studied after adjustment on age, American Society of Anesthesiologists, surgery, and postoperative curative anticoagulation. Complications related to TA administration were systematically reported. A total of 1909 patients were included - "no TA," n = 184; "IV," n = 1137; "IA," n = 214; and "IV + IA," n = 374. In the IV + IA group, a decrease in blood loss was observed compared to the no TA group (+ 220ml 95% confidence interval [CI] [184; 255] of RBC P < 0.001) and in the IA group (+ 65ml 95% CI [30; 99] of RBC P < 0.001). The length of hospital stay of the IV + IA group was shorter compared to the no TA group (hazard ratio [HR] 0.35, 95% CI [0.29; 0.43], P < 0.001) to the IA group (HR 0.57, 95% CI [0.48; 0.69], P < 0.001) and the IV group (HR 0.45, 95% CI [0.39; 0.50], P < 0.001). One case of deep vein thrombosis occurred in the group without TA. Administration of combined TA appears effective and safe; further studies are needed in order to establish a consensual protocol.

The aim of this study was to evaluate the radiographic effect of sagittal tibial osteotomy (STO), flexion tibial osteotomy (FTO) and deflexion tibial osteotomy (DTO) around the knee. It has been hypothesized that proximal STO modifies patellar height and could cause varus/valgus changes of the anatomical tibial axis: The purpose of the study was to verify this and to analyse these modifications. Patients underwent proximal STO in our department between 2007 and 2018: overall 28 consecutive patients (19 males, 9 females; 28 knees). Twelve patients underwent DTO, and 16 patients underwent FTO. Two independent observers measured the pre-operative and post-operative radiological indexes: posterior tibial slope, Caton-Deschamps Index (CDI) and Modified Insall-Salvati Index (MISI) in the lateral views; medial Tibial Plateau-Tibial Shaft (mTPTS) and medial Femoral Shaft-Tibial Shaft (mFTA) anatomical angles were measured in the frontal plane. No complications were reported at the average follow-up of 1.6 ± 1.1years. The mean mTPTS significantly increased from 0.6° ± 2.4° pre-operatively to 2.9° ± 2.6° of varus post-operatively (DTO (pre-operative 0.3 ± 3.1°, post-operative 2.4 ± 2.1°, ns); FTO (pre-operative 0.9 ± 1.9°, post-operative 3.2 ± 3.0°, P < 0.05)). The mean mFTA significantly reduced from 186.2° ± 4.9° pre-operatively to 182.7° ± 3.9° post-operatively (DTO (pre-operative 183.4 ± 3.3°, post-operative 180.6 ± 3.5°, ns); FTO (pre-operative 188.5 ± 4.9°, post-operative 184.4 ± 3.4°, P < 0.05)). The overall analysis reported no differences statistically significant in patellar height indexes. The main finding of this study is that STO slightly modifies tibial anatomical axes. This finding is more evident in FTOs. This surgical technique, due to its design, does not influence the patellar height. The tibial tuberosity osteotomy, performed in most of the cases to better expose tibial metaphysis and to avoid patellar tendon damages, provides another benefit that is the possibility to easily preserve the native patellar height. Sagittal tibial osteotomies slightly modify tibial anatomical axes in frontal plan without influencing the patellar height. This surgical procedure resulted to be effective and reliable in correcting the sagittal knee alignment but reporting, particularly of FTO, varus changes of anatomical tibial axis.

Introduction: Total hip replacement provides mostly fair functional and clinical results. Many factors play an essential role in hip stability and long-term outcomes. Surgical positioning remains fundamental for obtaining accurate implant fit and prevent hip dislocation or impingement. Different categories of robotic assistance have been established throughout the previous years and all of the technologies target accuracy and reliability to reduce complications, and enhance clinical outcomes. Materials and methods: An overview is proposed over the principles of robotic assistance in hip arthroplasty surgery. Accuracy, reliability, management of the bone stock, clinical outcomes, constraints and limits of this technology are reported, based on recent literature. Results: Potential advantages regarding pre-operative planning accuracy, cup positioning, maintenance of the center of rotation, preservation of an adequate bone stock nay clinical short- and mid-term outcomes are balanced with some reported disadvantages and limits like hip anatomical specificity, cost-effectiveness, engineering dependence. Discussion: The use of robotic-assisted THA presents clear and evident benefits related to accurate implant positioning and maintenance of a minimal bone while allowing. For some authors, an early improvement in functional results and patient’s recovery. This technology demonstrated a shorter surgical time and a short learning curve required to optimize its use and this technology presents promising outcomes and results and potential use in routine clinical application but its limitation of use is still present especially the cost of the robot, the need for the presence of an engineer during the surgery, its availability of use in all hospitals as well as the difficulty presented in dysplastic or dysmorphic hip joints.