Accuracy of Patient-Specific Template-Guided Versus Freehand Cervical Pedicle Screw Placement from C2 to C7: A Randomized Cadaveric Study

Free-hand technique of C7 pedicle screw insertion using a simply defined entry point without fluoroscopic guidance for cervical spondylotic myelopathy patients with C3 to C6 instrumented by lateral mass screws: a retrospective cohort study

BACKGROUND

Nowadays, both lateral mass screw (LMS) and pedicle screw were effective instrumentation for posterior stabilization of cervical spine. This study aims to evaluate the feasibility of a new free-hand technique of C7 pedicle screw insertion without fluoroscopic guidance for cervical spondylotic myelopathy (CSM) patients with C3 to C6 instrumented by lateral mass screws.

METHODS

A total of 53 CSM patients underwent lateral mass screws instrumentation at C3 to C6 levels and pedicle screw instrumentation at C7 level were included. The preoperative 3-dimenional computed tomography (CT) reconstruction images of cervical spine were used to determine 2 different C7 pedicle screw trajectories. Trajectory A passed through the axis of the C7 pedicle while trajectory B selected the midpoint of the base of C7 superior facet as the entry point. All these 53 patients had the C7 pedicle screw inserted through trajectory B by free-hand without fluoroscopic guidance and the postoperative CT images were obtained to evaluate the accuracy of C7 pedicle screw insertion.

RESULTS

Trajectory B had smaller transverse angle, smaller screw length, and smaller screw width but both similar sagittal angle and similar pedicle height when compared with trajectory A. A total of 106 pedicle screws were inserted at C7 through trajectory B and only 8 screws were displaced with the accuracy of screw placement as high as 92.5%.

CONCLUSION

In CSM patients with C3 to C6 instrumented by LMS, using trajectory B for C7 pedicle screw insertion is easy to both identify the entry point and facilitate the rod insertion.

Accuracy and safety of 3D printed surgical guides combined with monitored guidewires for placement of cervicothoracic pedicle screws: Technical note

Subaxial cervical pedicle screws provide rigid fixation, but their placement poses an important neurovascular injury risk. 3D printed guides have successfully been used to place pedicle screws, but experience in the subaxial cervical spine is limited. We present a case of cervicothoracic dissociation after a pathological fracture due to tumour involvement of the upper thoracic spine, causing paraparesis and intense pain. The cervicothoracic junction is of difficult visualization on fluoroscopy and the patients' severe instability made navigation unreliable. 3D printed individualized guidewire guides were used to help place canulated pedicle screws from C4 to T6. We successfully report the use of impedance guidewire monitoring to prevent pedicle violation and improve procedure safety.

Partial sacrectomy with patient-specific osteotomy guides

Background

Chordomas are rare, locally aggressive, malignant tumors. Surgical resection with sufficient margins defines the outcome. However, the necessity for wide margins often leads to sacrifice of important neurological structures. 3D-printed osteotomy guides are a promising solution for precise execution of surgical resection. We present probably the first sacrococcygeal chordoma resection with 3D-printed guides.

Methods

The case of a 49-year-old woman with a sacrococcygeal chordoma, resected with help of 3-D pre-operative planning and patient-specific 3D-printed osteotomy guides, is reported in detail.

Results

A sufficient tumor excision could be performed successfully while sparing nerve root S4. The planed margin has been exactly maintained, as confirmed by histology. The patient demonstrated an excellent clinical outcome with no evidence of local recurrence.

Conclusions

3-D pre-operative planning and patient-specific osteotomy guides can be used for planning and performing en-bloc surgical resection of sacral chordomas.

Combined Percutaneous Kyphoplasty/Pediculoplasty by Posterolateral Transpedicular Approach for Painful Cervical Spine Metastases: A Single-Center Prospective Study

Purpose

In patients requiring percutaneous kyphoplasty (PKP) for painful cervical spine metastases (PCSMs), the surgical approach is of utmost importance. Anterolateral and transoral routes are generally used at present, whereas PKP as well as percutaneous pediculoplasty (PPP) via posterolateral transpedicular approach (PTPA) has yet to be pursued in the treatment of PCSMs. The study was designed to evaluate safety and efficacy of PKP procedures combined with PPP via PTPA as treatment of PCSMs.

Patients and Methods

The patients with PCSMs were enrolled and housed in a database. The pain intensity of enrolled patients was gauged by Visual Analog Scale (VAS), ranging from 0 (none) to 10 (extreme). After preprocedural imaging assessment, combined PKP/PPP via PTPA was performed under the guidance of CT and fluoroscopic monitoring. Postprocedural VAS scores, complications, cement dosage, and hospitalization were recorded in the database for analysis. All cases were followed up for 6 months.

Results

Adult enrollees (7 women, 4 men) with PCSMs successfully underwent PKP/PPP via PTPA between February 2019 and January 2020, injected with 3.7±0.7 mL (range, 2.5-4.8 mL) of cement on average. Other than a single instance of asymptomatic cement leakage into paravertebral soft tissues, no complications ensued. Significant analgesic effects observed 24 hours after procedures were sustained for up to 6 months in follow-up surveys. Postprocedural hospitalizations were as brief as 2.2±0.8 days.

Conclusion

Combined PKP/PPP via PTPA is safe and effective as treatment of PCSMs, enabling quick pain relief and patient recovery.

Finding NEEMO: towards organizing smart digital solutions in orthopaedic trauma surgery

There are many digital solutions which assist the orthopaedic trauma surgeon. This already broad field is rapidly expanding, making a complete overview of the existing solutions difficult.The AO Foundation has established a task force to address the need for an overview of digital solutions in the field of orthopaedic trauma surgery.Areas of new technology which will help the surgeon gain a greater understanding of these possible solutions are reviewed.We propose a categorization of the current needs in orthopaedic trauma surgery matched with available or potential digital solutions, and provide a narrative overview of this broad topic, including the needs, solutions and basic rules to ensure adequate use in orthopaedic trauma surgery. We seek to make this field more accessible, allowing for technological solutions to be clearly matched to trauma surgeons' needs. Cite this article: EFORT Open Rev 2020;5:408-420. DOI: 10.1302/2058-5241.5.200021.

Anatomic techniques for cervical pedicle screw placement

Instrumentation of the cervical spine with cervical pedicle screws (CPS) is beneficial in patients with various types of spinal pathology. Despite posing greater technical challenges, CPS instrumentation confers better fixation outcomes when compared to lateral mass screws. While developments in technology have augmented the accuracy of CPS insertion, mastery in freehand CPS insertion allows the aforementioned technologies to reach their full potential in improving patient outcomes. The aim of this article is to discuss freehand CPS insertion techniques as established in the current literature while sharing our experience in this context. A comprehensive literature search was performed using the following electronic databases: PubMed, Medline, and EMBASE. Full-text articles focusing on clinical studies with description of freehand techniques were included. Articles which were on cadaveric studies, drill jig, navigation or robotic technology were excluded. Thirteen primary references comprising 1,480 patients were included in this review. Majority of studies reported utilizing the cranial margin of lamina for C2 level as a landmark for entry point, as well as lateral to centre of the articular mass, and just medial to the lateral border of the superior articular process for C3-7 levels. Method of tracking and facilitation of trajectory was reported in multiple studies, with use of instruments ranging from curved pedicle probes to high-speed burrs. Limited studies reported specific trajectories of CPS insertion. Most studies noted testing pedicle wall integrity at various checkpoints, with pedicle screw repositioning or conversion to lateral screw mass following detection of perforation or screw malpositioning. Success in CPS insertion rests on meticulous preoperative planning to identify the ideal screw entry point and trajectory. Patient-specific drill jigs, navigation and robotic technologies, while beneficial to progress in the field of cervical spine surgery and patient outcomes, should serve primarily to augment good expertise in freehand CPS insertion technique.