Intraoperative computer-assisted prediction of intraarticular contact pressures in the knee during high tibial osteotomy.

Objectives: To develop an accurate intraoperative method to estimate changes in intraarticular contact pressures during high tibial osteotomy (HTO).

Methods: Changes in knee alignment and pressure were monitored in real time in seven cadaver specimens that received HTO. Intraarticular contact pressure (N/mm ) in each knee compartment was estimated based on extraarticularly acquired data (leg alignment, correction, and ankle tilt) and based on the application of an axial force of half bodyweight (400-450 N).

Improving the human-robot interface for telemanipulated robotic long bone fracture reduction: Joystick device vs. haptic manipulator.

Objectives: Intramedullary nailing is the treatment of choice for femoral shaft fractures. However, there are several problems associated with the technique, e.g.

Comparison of algorithms for automated femur fracture reduction.

Purpose: We designed an experiment to determine the comparative effectiveness of computer algorithms for performing automated long bone fracture reduction.

Methods: Automated reduction of 10 3D fracture models was performed using two computer algorithms, random sample matching (RANSAM) and Z-buffering (Z-Buffer), and one of five options of post-processing: none; iterative closest point algorithm (ICP); ICP-X1; ICP-X2; and ICP-X3. We measured the final alignment between the two fragments for each algorithm and post-processing option.

Repeatability and reproducibility of a telemanipulated fracture reduction system.

We evaluate the inter- and intraobserver variability of a telemanipulated femur fracture reduction system using a joystick device. Five examiners performed virtual reduction of 3D femur fracture models on two separate occasions. We assessed the inter- and intraobserver variability for the final alignment and reduction.

Robotic technique improves entry point alignment for intramedullary nailing of femur fractures compared to the conventional technique: a cadaveric study.

We aimed to test whether a robotic technique would offer more accurate access to the proximal femoral medullary cavity for insertion of an intramedullary nail compared to the conventional manual technique. The medullary cavity of ten femur specimens was accessed in a conventional fashion using fluoroscopic control. In ten additional femur specimens, ISO-C 3D scans were obtained and a computer program calculated the ideal location of the cavity opening based on the trajectory of the medullary canal.

Femoral malrotation after surgical treatment of femoral shaft fractures in children: a retrospective CT-based analysis.

Background: Rotational malalignment is an important and not always avoidable complication after surgical treatment of femoral shaft fractures. The purpose of this study was to determine the incidence of rotational malalignment in children after surgical treatment of femoral shaft fractures and to identify potential patient- and treatment-related risk factors based on data obtained from CT scans.

Methods: We conducted a retrospective analysis of all patients aged less than 15 years with femoral shaft fractures admitted to our level 1 trauma centre between January 2004 and July 2014.

Robotic distal locking of intramedullary nailing: Technical description and cadaveric testing.

Interlocked intramedullary nailing is the treatment of choice for femoral shaft fractures. However, distal locking is a technically challenging part of the procedure that can result in distal femoral malrotation and high radiation exposure. We have tested a robotic procedure for robotic distal locking based on the computation of a drilling trajectory on two calibrated fluoroscopic images.

Robotic guided waterjet cutting technique for high tibial dome osteotomy: A pilot study.

Background: Oscillating saws generate high levels of heat (up to 150°C), which can lead to tissue necrosis, delayed healing and infection. Abrasive waterjet-cutting techniques have been described as a new tool to perform bone cuts, with less heat generation.

Methods: Four lower-limbs of four human alcohol conserved cadavers were tested.

Sectioning the anterolateral ligament did not increase tibiofemoral translation or rotation in an ACL-deficient cadaveric model.

Purpose: The anterolateral ligament (ALL) has been proposed as a possible extra-articular stabiliser of the knee. Injury to the ALL may result in residual instability following surgical reconstruction of a ruptured anterior cruciate ligament (ACL). Few studies have evaluated the biomechanical role of the ALL.

Preoperative virtual reduction reduces femoral malrotation in the treatment of bilateral femoral shaft fractures.

Introduction: In bilateral femoral shaft fractures, significant malrotation (>15°) occurs in about 40 % of cases after intramedullary nailing. Most of the methods that provide rotational control during surgery are based on a comparison to the intact femur and, thus, not applicable for bilateral fractures. In this study, we evaluated if preoperative virtual reduction can help improving rotational alignment in patients with bilateral femoral shaft fractures.

The effect of distal tibial rotation during high tibial osteotomy on the contact pressures in the knee and ankle joints.

Purpose: Intraoperative fracture of the lateral cortex fractures of the tibia is a potential complication of high tibial osteotomy (HTO), which may result in inadequate rotational alignment of the distal tibia. Our aim was to determine how rotational malalignment of the distal tibial segment distal would affect intraarticular contact pressure distribution in the knee and ankle joints.

Methods: A medial, L-shaped opening-wedge HTO was performed on seven human lower body specimens.

[Dynamic versus static cement spacer in periprosthetic knee infection: A meta-analysis].

Background: The standard of care for treatment of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is two-stage revision arthroplasty. The cement spacer in the interim period can be classified as either a static/non-articulating spacers (e.g.

Intraoperative imaging of the shoulder: A comparison of two- and three-dimensional imaging techniques.

Background: Isocentric three-dimensional C-arms allow for more effective intraoperative fracture reduction control compared to two-dimensional imaging techniques. However, this design is not appropriate for shoulder scanning.

Objective: To assess the feasibility of using a newer generation variable isocentric flat detector 3D C-arm for intraoperative glenohumeral and acromioclavicular joint assessment and to compare the accuracy of its intraoperative 3D imaging technology to a standard two-dimensional (2D) flat detector fluoroscope.

Effect of medial opening wedge high tibial osteotomy on intraarticular knee and ankle contact pressures.

High tibial osteotomy (HTO) is a commonly used surgical technique for treating moderate osteoarthritis (OA) of the medial compartment of the knee by shifting the center of force towards the lateral compartment. Previous studies have documented the effects of HTO on the biomechanics of the knee. However, the effects of the procedure on the contact pressures within the ankle joint have not been as well described.

A cadaver study comparing intraoperative methods to analyze lower limb alignment.

Background: Conventional intraoperative determination of lower limb alignment is essential for orthopedic surgical treatment. Current methods include the cable, alignment rod, and axis board methods.

Question/purposes: Are there differences in accuracy and reliability? What are the individual differences in applicability and radiation exposure?

Methods: Twenty legs from 12 fresh-frozen cadavers were randomly selected.

Radiological outcome and intraoperative evaluation of a computer-navigation system for femoral nailing: a retrospective cohort study.

Aim: Intraoperative determinations of femoral antetorsion and leg length during fixation of femoral shaft fractures present a challenge. In femoral shaft fracture fixations, a computer-navigation system has shown promise in determining antetorsion and leg length discrepancies. This retrospective cohort study aimed to determine whether the use of computer navigation during femoral nailing procedures reduced postoperative femoral malrotation and leg length discrepancy, as well as the number of revision cases.

Range of motion assessment of the shoulder and elbow joints using a motion sensing input device: a pilot study.

Background: Motion sensing input devices could provide a practical and low-cost alternative method for repeated range of motion measurements. This study aimed to assess the reliability, accuracy and time requirements of a motion sensing input device (Microsoft Kinect) for ROM measurements comparing it with goniometer based measurements and subjective estimation.

Material And Methods: Full ROM was measured in 14 shoulder and elbow joints using the different methods.

Laser method for intraoperative evaluation of lower extremity alignment: comparison of a novel technique to CT and a conventional method.

Introduction: Accurate restoration of mechanical alignment is an important factor in reconstructive surgery of the lower extremity. Conventional intraoperative methods, such as using an electrocautery cable, provide only a momentary evaluation of alignment. In this study, we evaluated a novel technique using a laser emitter, which projected the mechanical axis of the lower extremity, providing continuous intraoperative information on alignment.

Navigated reconstruction of tibial head depression fractures by inflation osteoplasty.

Background: Articular fracture reduction control remains a challenge even with the development of computer-assisted surgery. The Kyphoplasty procedure has shown advantages in treating vertebral fractures. One case report showed successful reduction of acetabular fractures using Kyphoplasty.

Intra-operative assessment of femoral antetorsion using ISO-C 3D: a cadaver study.

Aim: The aim of this study was to check the feasibility and accuracy of measuring antetorsion during surgery using a mobile image intensifier (IF) with computed tomography (CT) function (ISO-C 3D; Siemens, Erlangen, Germany) in comparison to a conventional multi-slice CT scanner (LightSpeed QX/I CT; GE Healthcare, VA, USA).

Materials And Methods: A total of 10 intact femora with intact soft tissue of five fresh frozen cadavers were used. After fixation on a surgical table, IF CT scans of the hip and knee were performed at both 190° and 120° of scanning rotation.

Effects of a WLAN-based real time location system on outpatient contentment in a Level I trauma center.

Background: Pre-existing wireless local area network (WLAN) infrastructures enable the implementation of a real-time location system (RTLS) in the clinical setting. RTLS enable clinics to capture and process patient position data and link it with clinical data. The improvements in workflow and treatment brought about by RTLS may improve patient satisfaction.

3D navigated implantation of the glenoid component in reversed shoulder arthroplasty. Feasibility and results in an anatomic study.

Background: Reversed shoulder arthroplasty is an alternative to total shoulder arthroplasty for various indications. The long-term results depend on stable bone fixation, and correct positioning of the glenoid component. The potential contribution of image guidance for reversed shoulder arthroplasty procedures was tested in vitro.

The physiological range of femoral antetorsion.

Introduction: Intramedullary nailing is a common method for fixation of femoral diaphyseal shaft fractures. However, postoperative malrotation does occur in 20-30 % of patients, as intraoperative assessment of antetorsion remains difficult. The estimated average antetorsion angle is 15°.

Navigated vs arthroscopic-guided drilling for reconstruction of acromioclavicular joint injuries: accuracy and feasibility.

Background: Anatomical reconstruction of the coracoclavicular ligaments is a relatively new technique for acromioclavicular (AC) joint injuries.

Methods: Eighteen procedures (nine non-navigated, nine navigated) of anatomical reconstruction were performed minimally invasively, using the Tight Rope system, on cadaveric shoulders. Two Kirschner wires were placed, freehand under fluoroscopic control (non-navigated) or 3D C-arm navigated.