Anterior retropharyngeal fixation C1-2 for stabilization of atlantoaxial instabilities: study of feasibility, technical description and preliminary results.
ABSTRACT: Posterior transarticular screw fixation C1-2 with the Magerl technique is a challenging procedure for stabilization of atlantoaxial instabilities. Although its high primary stability favoured it to sublaminar wire-based techniques, the close merging of the vertebral artery (VA) and its violation during screw passage inside the axis emphasizes its potential risk. Also, posterior approach to the upper cervical spine produces extensive, as well as traumatic soft-tissue stripping. In comparison, anterior transarticular screw fixation C1-2 is an atraumatic technique, but has been neglected in the literature, even though promising results are published and lectured to date. In 2004, anterior screw fixation C1-2 was introduced in our department for the treatment of atlantoaxial instabilities. As it showed convincing results, its general anatomic feasibility was worked up. The distance between mid-sagittal line of C2 and medial border of the VA groove resembles the most important anatomic landmark in anterior transarticular screw fixation C1-2. Therefore, CT based measurements on 42 healthy specimens without pathology of the cervical spine were performed. Our data are compiled in an extended collection of anatomic landmarks relevant for anterior transarticular screw fixation C1-2. Based on anatomic findings, the technique and its feasibility in daily clinical work is depicted and discussed on our preliminary results in seven patients.
Project description:The posterior screw fixation in atlas via posterior arch and lateral mass, also called C1 "pedicle" screw, combined with C2 pedicle screw fixiation has shown better biomechanical stability in unstable atlantoaxial fractures. However, its popularization has to fulfill the limitation imposed by anatomical characteristics. The aim of this study was to explore the manipulation, effect, and safety of the atlantoaxial transpedicular screw fixation under "direct vision" for the treatment of unstable atlantoaxial fracture.All the patients diagnosed with unstable atlantoaxial fracture, who received surgery treatment of C1,C2 internal fixation from January 2012 to December 2014 were reviewed. Only these patients that were diagnosed with atlantoaxial unstability secondary to trauma and were treated with atlantoaxial transpedicular screw fixation under "direct vision" and iliac autograft were included. The safety of transpedicular screw placement, postoperative outcome, atlantoaxial stability, autograft fusion, and complications was observed and analyzed retrospectively. The pain visual analog scale (VAS) and the Japanese Orthopedic Association (JOA) score were used as surgical curative effect evaluation standards.We reviewed a total of 92 patients diagnosed with unstable atlantoaxial fracture, who received surgery treatment of C1,C2 internal fixation from January 2012 to December 2014, and 87 patients were treated with atlantoaxial transpedicular screw fixation under "direct vision" and were included this analysis. A total of 306 transpedicular screws in atlas and axis were placed successfully. All cases were followed-up >12 months. The overall breach rate was 11.36%. None of the breaches resulted in new-onset neurological sequela. The neurological status in cases with bilateral upper extremities numbness and lower extremities weakness had improved after surgery. At the latest follow-up, the neck VAS and JOA scores were significantly improved (P?<?.01) than those preoperatively. No cases demonstrated implantation failure and bone graft absorption on the postoperative x-ray films and CT scans.Atlantoaxial transpedicular screw fixation under "direct vision" and iliac autograft for the treatment of unstable atlantoaxial fracture has shown simple manipulation and efficient performance. Thus, the technique of C1-C2 fixation is feasible in treating unstable atlantoaxial fracture.
Project description:OBJECTIVE:Conventional techniques for atlantoaxial fixation and fusion typically pass cables or wires underneath C1 lamina to secure the bone graft between the posterior elements of C1-2, which leads to complications such as cerebrospinal fluid (CSF) leak and neurological injury. With the evolution of fixation hardware, we propose a novel C1-2 fixation technique that avoids the morbidity and complications associated with sublaminar cables and wires. METHODS:This technique entails wedging and anchoring a structural iliac crest graft between C1 and C2 for interlaminar arthrodesis and securing it using a 0-Prolene suture at the time of C1 lateral mass and C2 pars interarticularis screw fixation. RESULTS:We identified 32 patients who underwent surgery for atlantoaxial with our technique. A 60% improvement in pain-related disability from preoperative baseline was demonstrated by Neck Disability Index (p < 0.001). There were no neurologic deficits. Complications included 2 patients CSF leaks related to presenting trauma, 1 patient with surgical site infection, and 1 patient with transient dysphagia. The rate of radiographic atlantoaxial fusion was 96.8% at 6 months, with no evidence of instrumentation failure, graft dislodgement, or graft related complications. CONCLUSION:We demonstrate a novel technique for C1-2 arthrodesis that is a safe and effective option for atlantoaxial fusion.
Project description:OBJECTIVE:Surgery is indicated for basilar invagination (BI) in symptomatic patients. In many patients, symptoms and signs occur due to an upward-migrated and malaligned odontoid with fixed or mobile atlantoaxial instability. Posterior distraction and fixation of the atlantoaxial joints has evolved to become the standard of care, but has some inherent morbidity. In this study, we propose that the unilateral anterior submandibular retropharyngeal approach with customized wedge-shaped titanium cages inserted into both atlantoaxial joints and anterior atlantoaxial fixation with a plate screw construct is a safer and easier option in many cases of BI. METHODS:From February 2014 to February 2019, 52 patients (age range, 15-78 years; 40 males and 12 females) with symptomatic BI with atlantoaxial dislocation and minimal sagittal facetal inclination and only mild Chiari malformation without syringomyelia were offered anterior submandibular retropharyngeal atlantoaxial distraction and fixation surgery. RESULTS:Neurological improvement occurred in 80% of patients, while the neurological status of 20% remained unchanged. No patients worsened, and no major complications or mortality was observed. CONCLUSION:In properly selected cases of symptomatic BI, anterior wedge cage distraction with anterior atlantoaxial fixation is a safe and simple option.
Project description:Study Design Case series of seven patients. Objective C2 stabilization can be challenging due to the complex anatomy of the upper cervical vertebrae. We describe seven cases of C1-C2 fusion using intraoperative navigation to aid in the screw placement at the atlantoaxial (C1-C2) junction. Methods Between 2011 and 2014, seven patients underwent posterior atlantoaxial fusion using intraoperative frameless stereotactic O-arm Surgical Imaging and StealthStation Surgical Navigation System (Medtronic, Inc., Minneapolis, Minnesota, United States). Outcome measures included screw accuracy, neurologic status, radiation dosing, and surgical complications. Results Four patients had fusion at C1-C2 only, and in the remaining three, fixation extended down to C3 due to anatomical considerations for screw placement recognized on intraoperative imaging. Out of 30 screws placed, all demonstrated minimal divergence from desired placement in either C1 lateral mass, C2 pedicle, or C3 lateral mass. No neurovascular compromise was seen following the use of intraoperative guided screw placement. The average radiation dosing due to intraoperative imaging was 39.0 mGy. All patients were followed for a minimum of 12 months. All patients went on to solid fusion. Conclusion C1-C2 fusion using computed tomography-guided navigation is a safe and effective way to treat atlantoaxial instability. Intraoperative neuronavigation allows for high accuracy of screw placement, limits complications by sparing injury to the critical structures in the upper cervical spine, and can help surgeons make intraoperative decisions regarding complex pathology.
Project description:Anatomic orientation of the graft in anatomic anterior cruciate ligament reconstruction is the key to improved knee stability, restoration of normal knee kinematics, and the prevention of long-term joint degeneration. The graft position and orientation in the joint depend on the position of the tibial and femoral tunnels. Graft displacement in the tibial tunnel due to the position of the interference screw when the screw has proximal fixation also has an effect on the orientation of the graft. We have developed a technique for adjusting guidewire placement for the interference screw posterolaterally in the tibial tunnel in anatomic single-bundle anterior cruciate ligament reconstruction. This technique helps to push the graft medially and anteriorly in the tibial tunnel, avoids impingement of the graft with the lateral femoral condyle, and helps to maintain the orientation of the graft in a more anatomic way.
Project description:Whereas "anatomic" anterior cruciate ligament reconstruction may improve clinical results, the technique has introduced new technical challenges. The purpose of this technical note and video is to explore tips and tricks that improve femoral socket drilling with a retrograde reamer, bone-patellar tendon-bone graft passage, and interference screw fixation. The techniques for retrograde femoral socket drilling in an inside-out direction, bone-patellar tendon-bone graft passage, and interference screw fixation are described and demonstrated. Pitfalls, troubleshooting tips, and possible solutions are discussed. With the retrograde reamer, the femoral socket can be placed in the footprint of the anterior cruciate ligament with a longer and more vertical tunnel. By modifying the size of the patellar bone plug, graft passage is improved. With care and technique, interference screw fixation in the femoral socket over a guidewire is possible.
Project description:Injuries of the distal tibiofibular syndesmosis are commonly overlooked or mismanaged, and chronic instability is a debilitating condition leading to premature joint degeneration. Several methods of treatment have been described, mainly screw fixation, arthrodesis, or ligament reconstruction. Most clinical evidence is limited to case series, mainly screw fixation, and there is a general paucity of evidence regarding ligament reconstruction, which is considered to be more anatomic and to restore joint biomechanics. Most papers describe open techniques. We describe an original technique for all-inside anatomic arthroscopic graft reconstruction of the anterior-inferior tibiofibular ligament, which is simpler than other previously described reconstruction procedures. In addition to being performed through standard ankle arthroscopy portals, we believe this technique avoids potential complications.
Project description:Tibial eminence fractures are an uncommon but well-described avulsion of the anterior cruciate ligament. Treatment principles are based on the amount and pattern of fracture displacement. Management has evolved from closed reduction and immobilization to arthroscopic reduction and internal fixation followed by early rehabilitation. Various fixation methods have evolved, ranging from arthroscopic reduction and percutaneous screw fixation to arthroscopic suture repair. We present a technique for arthroscopic reduction and internal fixation using a cannulated drill bit and high-strength suture. This technique facilitates anatomic reduction with uncomplicated tunnel placement and suture passing in an effort to allow strong fixation and early rehabilitation.
Project description:Occipitocervical instability may be attributed to congenital, bony/ligamentous abnormalities, trauma, neoplasm, degenerative bone disease, and failed atlantoaxial fixation. Indications for occipitocervical fixation include the prevention of disabling pain, cranial nerve dysfunction, paralysis, or even sudden death.The screw trajectory for the modified transcondylar screw (mTCS) is optimally planned utilizing a three-dimensional skull reconstructed image.The modified mTCS technique is helpful where there is a loss of bone, such as after prior suboccipital craniotomy and/or an inadequate occipital condyle. The new proposed technique is similar to the classical transcondylar screw placement but follows a deeper course along the bony lip of foramen magnum toward clivus from a dorsolateral approach.The modified mTCS technique allows for direct visualization and, therefore, helps to avoid damage to the hypoglossal nerve and lateral aspect of brain stem.
Project description:Purpose. To investigate a novel computed method to reconstruct the bilateral digital interarticular channel of atlas and its potential use on the anterior upper cervical screw fixation. Methods. We have used the reverse engineering software (image-processing software and computer-aided design software) to create the approximate and optimal digital interarticular channel of atlas for 60 participants. Angles of channels, diameters of inscribed circles, long and short axes of ellipses were measured and recorded, and gender-specific analysis was also performed. Results. The channels provided sufficient space for one or two screws, and the parameters of channels are described. While the channels of females were smaller than that of males, no significant difference of angles between males and females were observed. Conclusion. Our study demonstrates the radiological features of approximate digital interarticular channels, optimal digital interarticular channels of atlas, and provides the reference trajectory of anterior transarticular screws and anterior occiput-to-axis screws. Additionally, we provide a protocol that can help make a pre-operative plan for accurate placement of anterior transarticular screws and anterior occiput-to-axis screws.