How Does Robotic-Arm Assisted Technology Influence Total Knee Arthroplasty Implant Placement for Surgeons in Fellowship Training?

Implant malalignment during total knee arthroplasty (TKA) may lead to suboptimal postoperative outcomes. Accuracy studies are typically performed with experienced surgeons; however, it is important to study less experienced surgeons when considering teaching hospitals where younger surgeons operate. Therefore, this study assessed whether robotic-arm assisted TKA (RATKA) allowed for more accurate and precise implant position to plan when compared with manual techniques when the surgery is performed by in-training orthopaedic surgical fellows. Two surgeons, currently in their fellowship training and having minimal RATKA experience, performed a total of six manual TKA (MTKA) and six RATKAs on paired cadaver knees. Computed tomography scans were obtained for each knee pre- and postoperatively. These scans were analyzed using a custom autosegmentation and autoregistration process to compare postoperative implant position with the preoperative planned position. Mean system errors and standard deviations were compared between RATKA and MTKA for the femoral component for sagittal, coronal, and axial planes and for the tibial component in the sagittal and coronal planes. A 2-Variance testing was performed using an α = 0.05. Although not statistically significant, RATKA was found to have greater accuracy and precision to plan than MTKA for: femoral axial plane (1.1° ± 1.1° vs. 1.6° ± 1.3°), coronal plane (0.9° ± 0.7° vs. 2.2° ± 1.0°), femoral sagittal plane (1.5° ± 1.3° vs. 3.1° ± 2.1°), tibial coronal plane (0.9° ± 0.5° vs. 1.9° ± 1.3°), and tibial sagittal plane (1.7° ± 2.6° vs. 4.7° ± 4.1°). There were no statistical differences between surgical groups or between the two surgeons performing the cases. With limited RATKA experience, fellows showed increased accuracy and precision to plan for femoral and tibial implant positions. Furthermore, these results were comparable to what has been reported for an experienced surgeon performing RATKA.

Less iatrogenic soft-tissue damage utilizing robotic-assisted total knee arthroplasty when compared with a manual approach: A blinded assessment.

OBJECTIVES: The use of the haptically bounded saw blades in robotic-assisted total knee arthroplasty (RTKA) can potentially help to limit surrounding soft-tissue injuries. However, there are limited data characterizing these injuries for cruciate-retaining (CR) TKA with the use of this technique. The objective of this cadaver study was to compare the extent of soft-tissue damage sustained through a robotic-assisted, haptically guided TKA (RATKA) versus a manual TKA (MTKA) approach. METHODS: A total of 12 fresh-frozen pelvis-to-toe cadaver specimens were included. Four surgeons each prepared three RATKA and three MTKA specimens for cruciate-retaining TKAs. A RATKA was performed on one knee and a MTKA on the other. Postoperatively, two additional surgeons assessed and graded damage to 14 key anatomical structures in a blinded manner. Kruskal-Wallis hypothesis tests were performed to assess statistical differences in soft-tissue damage between RATKA and MTKA cases. RESULTS: Significantly less damage occurred to the PCLs in the RATKA versus the MTKA specimens (p < 0.001). RATKA specimens had non-significantly less damage to the deep medial collateral ligaments (p = 0.149), iliotibial bands (p = 0.580), poplitei (p = 0.248), and patellar ligaments (p = 0.317). The remaining anatomical structures had minimal soft-tissue damage in all MTKA and RATKA specimens. CONCLUSION: The results of this study indicate that less soft-tissue damage may occur when utilizing RATKA compared with MTKA. These findings are likely due to the enhanced preoperative planning with the robotic software, the real-time intraoperative feedback, and the haptically bounded saw blade, all of which may help protect the surrounding soft tissues and ligaments.Cite this article: Bone Joint Res 2019;8:495-501.

Efficacy of Arthroscopic Teaching Methods: A Prospective Randomized Controlled Study.

Arthroscopic education research recently has been focused on the use of skills labs to facilitate resident education and objective measure development to gauge technical skill. This study evaluates the effectiveness of three different teaching methods. Medical students were randomized into three groups. The first group received only classroom-based lecture. The second group received the same lecture and 28 minutes of lab-based hands-off arthroscopy instruction using a cadaver and arthroscopy setup. The final group received the same lecture and 7 minutes of hands-on arthroscopy instruction in the lab on a cadaver knee. The arthroscopic knee exam that followed simulated a diagnostic knee exam and subjects were measured on task completion and by the number of look downs. The number of look downs and the number of tasks completed did not achieve statistical significance between groups. Posttest survey results revealed that the hands-on group placed significantly more value on their educational experience as compared with the other two groups. (Journal of Surgical Orthopaedic Advances.

Polyaxial Screws in Locked Plating of Tibial Pilon Fractures.

This study examined the axial and torsional stiffness of polyaxial locked plating techniques compared with fixed-angle locked plating techniques in a distal tibia pilon fracture model. The effect of using a polyaxial screw to cross the fracture site was examined to determine its ability to control relative fracture site motion. A laboratory experiment was performed to investigate the biomechanical stiffness of distal tibia fracture models repaired with 3.5-mm anterior polyaxial distal tibial plates and locking screws. Sawbones Fourth Generation Composite Tibia models (Pacific Research Laboratories, Inc, Vashon, Washington) were used to model an Orthopaedic Trauma Association 43-A1.3 distal tibia pilon fracture. The polyaxial plates were inserted with 2 central locking screws at a position perpendicular to the cortical surface of the tibia and tested for load as a function of axial displacement and torque as a function of angular displacement. The 2 screws were withdrawn and inserted at an angle 15° from perpendicular, allowing them to span the fracture and insert into the opposing fracture surface. Each tibia was tested again for axial and torsional stiffness. In medial and posterior loading, no statistically significant difference was found between tibiae plated with the polyaxial plate and the central screws placed in the neutral position compared with the central screws placed at a 15° position. In torsional loading, a statistically significant difference was noted, showing greater stiffness in tibiae plated with the polyaxial plate and the central screws placed at a 15° position compared with tibiae plated with the central screws placed at a 0° (or perpendicular) position. This study showed that variable angle constructs show similar stiffness properties between perpendicular and 15° angle insertions in axial loading. The 15° angle construct shows greater stiffness in torsional loading.

Anterolateral and medial locking plate stiffness in distal tibial fracture model.

BACKGROUND: The purpose of this study was to compare the axial and torsional stiffness between anterolateral and medial distal tibial locking plates in a pilon fracture model. MATERIALS AND METHODS: The biomechanical stiffness of anterolateral or medial plated pilon fracture models was evaluated. Six Sawbones Composite Tibiae with a simulated pilon fracture representing varus or valgus comminution (OTA 43-A2.2) were plated with a Synthes 3.5-mm contoured LCP anterolateral or medial locking distal tibia plate. Load as a function of axial displacement and torque as a function of angular displacement were recorded. Each tibia was tested with a fracture wedge in place and removed with a medial and then anterolateral plate. RESULTS: Loading the tibial plateau medial to the central axis, no significant difference in mean stiffness between the anterolateral and medial plates was demonstrated with the fracture wedge in place. A significant difference was demonstrated with the wedge removed. Loading the plateau posterior to the central axis, no significant difference in mean stiffness between plates was demonstrated with the wedge in place or removed. With the wedge in place, there was a significant difference in mean torsional stiffness for clockwise rotation, but not counterclockwise rotation. With the wedge removed, no significant difference appeared in mean stiffness for clockwise and counterclockwise rotation. CONCLUSION: Distal tibia extra-articular fractures stabilized with anterolateral or medial locking plate constructs demonstrated no statistically significant difference in biomechanical stiffness in compression and torsion testing. CLINICAL RELEVANCE: We believe this study indicates the primary concern when treating a pilon fracture may be soft-tissue considerations. Further clinical studies are required before definitive changes can be recommended regarding pilon fracture fixation.

Thromboprophylaxis after multiple trauma: what treatment and for how long?

A review of current literature discussing thromboprophylaxis in the multiple-trauma patient to provide insight on the type of treatment and its duration of use. AMEDLINE search was conducted in May 2009 using keywords associated with thromboprophylactic measures in multiple-trauma patient care, including inferior vena cava (IVC) filters, mechanical-compression devices and anticoagulants. Abstracts were evaluated for relevance to this study and full-text articles were then examined individually. Fourteen full text articles were evaluated including guidelines published by the American College of Chest Physicians (ACCP) and the Eastern Association for the Surgery of Trauma (EAST) and other studies dealing with multiple-trauma patients, including those in hip-fracture surgery, lower-leg trauma and head trauma. Limited research has been performed for the multiple-trauma patient and recommendations regarding the type of treatment and its duration of use cannot be suggested beyond what has been extrapolated from existing trauma and major surgery patients. IVC filters, mechanical compression devices and anticoagulants therefore remain the standard, but their duration of use in the multiple-trauma patient is not well described. New oral anticoagulants that inhibit factor Xa or thrombin directly show promising qualities but have not been evaluated for multiple-trauma applications. Therefore, optimal thromboprophylaxis and its duration after multiple trauma is largely based on rational, clinical decision making on a case-by-case basis.