Simultaneous use of cannulated reamer and schanz screw for closed intramedullary femoral nailing

The Clinical Application of Augmented Reality in Orthopaedics: Where Do We Stand?

PURPOSE OF REVIEW

The surgical community is constantly working to improve accuracy and reproducibility in patient care, with the goal to improve patient outcomes and efficiency. One area of growing interest with potential to meet these goals is in the use of augmented reality (AR) in surgery. There is still a paucity of published research on the clinical benefits of AR over traditional techniques, but this article aims to present an update on the current state of AR within orthopaedics over the past 5 years.

RECENT FINDINGS

AR systems are being developed and studied for use in all areas of orthopaedics. Most recently published research has focused on the areas of fracture care, adult reconstruction, orthopaedic oncology, spine, and resident education. These studies have shown some promising results, particularly in surgical accuracy, decreased surgical time, and less radiation exposure. However, the majority of recently published research is still in the pre-clinical setting, with very few studies using living patients. AR supplementation in orthopaedic surgery has shown promising results in pre-clinical settings, with improvements in surgical accuracy and reproducibility, decreased operating times, and less radiation exposure. Most AR systems, however, are still not approved for clinical use. Further research is needed to validate the benefits of AR use in orthopaedic surgery before it is widely adopted into practice.

Development of a novel fracture fragment stabilization system for minimally invasive osteosynthesis and in vitro comparison to traditional Kern bone reduction forceps

OBJECTIVE

To develop and evaluate a novel fracture fragment stabilization system, the Sirius minimally invasive bone reduction handle system (SMH), in an artificial fracture model (FxM) simulating a canine femoral fracture repair with a minimally invasive orthopedic approach.

STUDY DESIGN

In vitro experimental study.

SAMPLE POPULATION

Synthetic fractured femurs with soft-tissue coverage analog (n = 8).

METHODS

The developed SMH consisted of modified Kern forceps connected with existing external skeletal fixation components. Intramedullary Steinman pin placement with the SMH or traditional Kern forceps only (KO) was performed by 16 participants in randomized order. Demographics and surgical experience of participants and outcome variables (fragment movement, early/final gap formation, time of procedure, assessed practicability by visual analog scale) were recorded and statistically evaluated.

RESULTS

The SMH was more difficult and took longer to assemble (P = .031 and P = .008); SMH resulted in a smaller final reduction gap (P = .008). More surgical experience resulted in faster surgery times (R² = 0.766) but was not correlated with final fracture gap formation.

CONCLUSION

The SMH was associated with reduced fragment gap formation in this simulated setting.

CLINICAL SIGNIFICANCE

The SMH may be helpful for maintaining reduction of femoral fractures in dogs. Additional studies of the SMH should be conducted to fully assess the effectiveness and practicality in clinical cases.

[Reduction techniques in intramedullary nailing osteosynthesis]

Intramedullary nailing was originally conceived for the stabilization of shaft fractures of long bones. Due to new nail designs and multiple interlocking possibilities, the spectrum of nailing has significantly increased. Nailing of fractures beyond the isthmus is technically challenging because fractures need to be reduced before the nailing procedure starts. Indirect techniques of reduction include the use of an extension table, a large distractor or an external fixator. Direct reduction with pointed reduction forceps, lag screws, a cerclage wire or a short plate can optimize indirect reduction. The choice of the correct entry portal is of utmost importance for an optimal operative result. The location of the entry portal is dependent on the local anatomy and the bend of the nail. The optimal entry portal at the proximal tibia is directly behind the patellar tendon and accessible with the knee in more than 90° of flexion, alternatively through a suprapatellar approach with a slightly flexed knee joint. Insertion of the nail through the suprapatellar approach is possible without stress on the reduced fracture fragments. Blocking screws create an artificial isthmus in the metaphyseal area and force the guide wire in the desired direction. Blocking screws help to avoid axial malalignment during nail insertion. Interlocking of the nail with screws coming from different directions prevents secondary dislocation.

Radiation-free methods for navigated screw placement in slipped capital femoral epiphysis surgery

PURPOSE

For orthopedic procedures, surgeons utilize intra-operative medical images such as fluoroscopy to plan screw placement and accurately position the guide wire with the intended trajectory. The number of fluoroscopic images needed depends on the complexity of the case and skill of the surgeon. Since more fluoroscopic images lead to more exposure and higher radiation dose for both surgeon and patient, a solution that decreases the number of fluoroscopic images would be an improvement in clinical care.

METHODS

This article describes and compares three different novel navigation methods and techniques for screw placement using an attachable Inertial Measurement Unit device or a robotic arm. These methods provide projection and visualization of the surgical tool trajectory during the slipped capital femoral epiphysis procedure.

RESULTS

These techniques resulted in faster and more efficient preoperative calibration and set up times compared to other intra-operative navigation systems in our phantom study. We conducted an experiment using 120 model bones to measure the accuracy of the methods.

CONCLUSION

As conclusion, these approaches have the potential to improve accuracy of surgical tool navigation and decrease the number of required X-ray images without any change in the clinical workflow. The results also show 65% decrease in total error compared to the conventional manual approach.

Malalignment in intramedullary nailing. How to achieve and to maintain correct reduction?

Intramedullary nailing has become the standard for the treatment of long bones diaphyseal fractures. Modern techniques of locking have further enlarged the primary indications to more proximal and distal fractures relying upon a former correct alignment. Nevertheless, residual deformities are not rare as once the nail has left the narrow diaphyseal canal and comes into the wider metaphysis, it may follow an unwished trajectory. There is also a chance for malreduction in diapyhseal fractures. The more complex the fracture is, the more difficult its reduction, not only for the alignment of the proximal or the distal part of bone in relation to the diaphysis, but also correct rotation and length. In this paper, we analyze recommended techniques to achieve accurate bone fracture reduction, to avoid post-operative deformities combined with correct implant insertion.

Multi-modal intra-operative navigation during distal locking of intramedullary nails

The interlocking of intramedullary nails is a technically demanding procedure which involves a considerable amount of X-ray acquisitions; one study lists as many as 48 to successfully complete the procedure and fix screws into 4-6 mm distal holes of the nail. We propose to design an augmented radiolucent drill to assist surgeons in completing the distal locking procedure without any additional X-ray acquisitions. Using an augmented reality fluoroscope that coregisters optical and X-ray images, we exploit solely the optical images to detect the augmented radiolucent drill and estimate its tip position in real-time. Consequently, the surgeons will be able to maintain the down the beam positioning required to drill the screws into the nail holes successfully. To evaluate the accuracy of the proposed augmented drill, we perform a preclinical study involving six surgeons and ask them to perform distal locking on dry bone phantoms. Surgeons completed distal locking 98.3% of the time using only a single X-ray image with an average navigation time of 1.4 ± 0.9 min per hole.

Improved screw placement for slipped capital femoral epiphysis (SCFE) using robotically-assisted drill guidance

Slipped Capital Femoral Epiphysis (SCFE) is a common hip displacement condition in adolescents. In the standard treatment, the surgeon uses intra-operative fluoroscopic imaging to plan the screw placement and the drill trajectory. The accuracy, duration, and efficacy of this procedure are highly dependent on surgeon skill. Longer procedure times result in higher radiation dose, to both patient and surgeon. A robotic system to guide the drill trajectory might help to reduce screw placement errors and procedure time by reducing the number of passes and confirmatory fluoroscopic images needed to verify accurate positioning of the drill guide along a planned trajectory. Therefore, with the long-term goals of improving screw placement accuracy, reducing procedure time and intra-operative radiation dose, our group is developing an image-guided robotic surgical system to assist a surgeon with pre-operative path planning and intra-operative drill guide placement.