Percutaneous Posterior Cervical Pedicle Instrumentation (C1 to C7) With Navigation Guidance: Early Series of 27 Cases

A surgeon-controlled mode of robotic assistance with posterolateral approach helps achieve highly medialized cervical pedicle screw placement to avoid vertebral artery injury

PURPOSE

The small pedicle widths, the thin lateral cortical shell next to the vertebral artery (VA), and the strongly tilted pedicle axis anteromedially narrow the safety margin for cervical pedicle screw (CPS) placement against vertebral artery (VA) injury. We have studied whether the minimally invasive surgery (MIS) of a posterolateral approach with a table-mounted, surgeon-controlled mode of robotic assistance (group R) improves the VA safety compared to C-arm fluoroscopy-guided conventional open technique (group F).

METHODS

Group R consisted of 165 screws in 37 patients and group F, 199 screws in 52 patients. The two groups covered a broad range of vertebral levels from C2 to C7 with comparable distribution (p = 0.0512) for treating a similar variety of diseases (p = 0.6958).

RESULTS

Group R, compared with group F, showed a greater lateral-to-medial CPS inclination (p ≤ 0.0004) that even exceeded the obliquity of corresponding pedicle axis, leading to a higher rate of acceptable CPS placement (93.4% vs. 85.4%; p = 0.0164) with a lower rate of lateral breach (1.2% vs. 10.1%; p = 0.0004).

CONCLUSION

For CPS placement, robot-assisted MIS obviously eliminates morbidity-prone soft-tissue dissection, radiation exposure to the surgical team, and human manual errors. The current study revealed its additional benefit of better safety against VA injury by allowing us to place CPS with a steep lateral-to-medial angulation owing to (1) a lack of counter pressure from the paravertebral muscles and (2) minimizing a navigation pitfall of untracked pressure-induced vertebral rotation.

A new minimally invasive cervical pedicle screw (CPS) fixation system using intra-operative computed tomography-guided navigation

Background

Since its introduction, placement of cervical pedicle screws (CPS) has been considered a procedure with a very high-risk profile. Minimally invasive CPS placement was not even considered at all. However, as surgical techniques and image guided intra-operative navigation have been refined over the last decade, navigated CPS placement has become a standard procedure in well-established spine centers. Currently, the first off-the-shelf percutaneous CPS placement platforms are becoming available. The aim of this study is to assess feasibility and accuracy of an minimally invasive surgery (MIS) CPS fixation system in a pilot series.

Methods

Between January and July 2023, we treated a cohort of ten patients using a new cervical MIS platform. Forty pedicle screws were inserted percutaneously in the c-spine using intra-operative computed tomography (CT) guided navigation and retrospectively analysed for accuracy using a modified Gertzbein & Robbins (G&R) classification. Adverse events and other patient-related data were also documented.

Results

Ninety percent of all screws were placed accurately (80% on perfect trajectory, 10% showed minor perforations). Another 10% (four screws) caused pedicle wall breaches between 2 and 4 mm, but were not revised, since misplacement was not associated with neurological deficit or inferior biomechanics. One patient experienced neurological deterioration, but not associated with screw misplacement. The transverse foramen was breached twice, however not endangering the vertebral arteries.

Conclusions

In this pilot series MIS CPS placement yielded accurate placement rates comparable to open surgical approaches reported in the literature. Hence, MIS CPS placement appears to be a feasible and safe procedure in selected cases.

Navigated percutaneous placement of cervical pedicle screws: An anatomical feasibility study

Introduction

Percutaneous cervical pedicle screw placement is challenging due to complex anatomy, and requires navigation support. It is unclear how to ensure navigation accuracy in minimally invasive procedures.

Research question

How accurate is image-guided percutaneous pedicle screw positioning after referencing with only one clamp for the complete subaxial cervical spine?

Materials and methods

In six cadavers, all subaxial cervical pedicles were fitted with screws using a standardized procedure. Briefly, a reference clamp was placed via a small skin incision on spinous process C7. The procedure started from C3 and progressed towards C7, without additional imaging, using one registration for all vertebrae. Screws were placed using a navigated screwdriver. Cone-beam CT was performed at three time-points. Screw position was directly intraoperatively evaluated by the surgeons using a modified classification-from Grade 1 (perfect placement) to Grade 5 (highly inaccurate)-and these data were re-evaluated by two independent radiologists.

Results

In six human specimens, 10 guidewires each were placed bilaterally in C3-C7. One screw (1.7%) was intraoperatively classified as Grade 3, but as Grade 4 in the second assessment. All other screws were classified as Grades 1-2 (89.8%) or 3 (8.5%). Screw placement accuracy was not significantly impacted by distance to the clamp or side selection.

Discussion

In percutaneously navigated screw placement with intraoperative imaging, safe screw placement was possible with a reference clamp on C7. Clinical application of this technique has been limited to individual cases. We also propose a new classification for improving screw accuracy and clinical consequences.

Minimally Invasive Surgery for Posterior Atlantoaxial Lateral Mass Joint Fusion (MIS-PALF): A Muscle-Sparing Procedure for Atlantoaxial Instability or Dislocation

BACKGROUND

Conventional surgical procedures for atlantoaxial instability or dislocation (AAI/D) have been associated with a high prevalence of postoperative occipitocervical pain and dysfunction, as well as substantial perioperative blood loss. We hypothesized that minimally invasive surgery for posterior atlantoaxial lateral mass joint fusion (MIS-PALF), a procedure that can largely avoid disruption of suboccipital musculature, would be superior to the standard Goel-Harms technique in terms of postoperative pain and perioperative blood loss.

METHODS

This was a prospective cohort study of patients undergoing MIS-PALF for AAI/D at Peking University Third Hospital's Department of Orthopaedics from January 2021 to December 2021 and a historical control group of patients with the same diagnoses who were treated with the Goel-Harms technique. The duration of surgery, perioperative blood loss, postoperative length of hospital stay, postoperative body temperature, pain, supplementary use of narcotics, spinal cord function/improvement (assessed using the Japanese Orthopaedic Association [JOA] scores), reduction of AAI/D (determined based on radiographic parameters), rate of successful fusion, and complication rate were all compared between the 2 groups.

RESULTS

No significant differences were noted between the groups (43 MIS-PALF cases, 86 control cases) regarding baseline data, operative time, spinal cord function or improvement, reduction of AAI/D, rate of successful fusion, and complication rate. MIS-PALF was associated with significantly less perioperative blood loss, a shorter postoperative hospital stay (decreased by 30.8%), lower intensity and frequency of postoperative pain (decreased by 10.6% and 61.9%, respectively), less need for supplementary narcotics, and less frequent postoperative fever (decreased by 48.7%).

CONCLUSIONS

This was the first prospective cohort study of which we are aware on minimally invasive procedures for atlantoaxial fusion. Clinical efficacy (AAI/D reduction, rate of successful atlantoaxial fusion, JOA score improvement), efficiency (operative time), and safety (complications) of MIS-PALF appeared to be noninferior to those of the Goel-Harms technique. MIS-PALF was superior in terms of postoperative occipitocervical pain and length of hospital stay, both of which directly affect overall patient satisfaction and postoperative recovery of quality of life.

LEVEL OF EVIDENCE

Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Comparison of different imaging devices and navigation systems for cervical pedicle screw placement: an experimental study on screw accuracy, screw placement time and radiation dose

Cervical pedicle screws (CPS) provide biomechanically superior fixation compared to other techniques but are technically more demanding. Navigated CPS placement has been increasingly reported as a safe and accurate technique, yet there are few studies comparing different combinations of imaging and navigation systems under comparable conditions. With this study, we aimed to compare different imaging and navigation systems for CPS placement in terms of accuracy, screw placement time and applied radiation dose. For this experimental study, navigated CPS placement was performed at levels C2 to C7 in 24 identical radiopaque artificial spine models by two surgeons with different levels of experience using three different combinations of intraoperative 3D imaging devices and navigation systems. Accuracy, time and radiation dose were compared between the groups. In total, 288 screws were placed. Accuracy was > 98% in all groups with no significant differences between groups or between surgeons (P = 0.30 and P = 0.31, respectively), but the inexperienced surgeon required significantly more time (P < 0.001). Radiation dose was significantly higher with iCT compared to CBCT (P < 0.0001). Under experimental conditions, accuracy rates of > 98% were achieved for navigated CPS placement regardless of the imaging modality or navigation system used. Radiation doses were significantly lower for CBCT compared to iCT guidance.

Mazor X robot-assisted upper and lower cervical pedicle screw fixation: a case report and literature review

BACKGROUND

Manual placement of cervical pedicle screws is risky, and robot-assisted placement of atlantoaxial pedicle screws has not been reported.

CASE REPORT

We describe a 74-year-old female patient with atlantoaxial fracture and dislocation combined with spinal cord injury caused by a car accident. The left lower limb muscle strength was grade 0, the right upper limb muscle strength was grade 1, and the right lower limb muscle strength was grade 2. Loss of sensation below the clavicle level, decreased superficial sensation in the extremities, loss of deep sensation in the left lower extremity, and incontinence were observed. We successfully placed atlas pedicle screws with the assistance of the Mazor X robot. One week after the operation, radiological imaging revealed that the reduction effect was good, the placement of the pedicle screws was satisfactory, the left upper limb and left lower limb muscle strength was level 2, the right upper limb and the muscle strength of the right lower limb were grade 3, and the sensory function was partially restored. No complications related to screw placement were found at the 3-month postoperative follow-up.

CONCLUSIONS

Mazor X robot-assisted descending pedicle screw fixation of the atlas is feasible and safe.

Evolution of Cervical Endoscopic Spine Surgery: Current Progress and Future Directions-A Narrative Review

Cervical endoscopic spine surgery is rapidly evolving and gaining popularity for the treatment of cervical radiculopathy and myelopathy. This approach significantly reduces muscular damage and blood loss by minimizing soft tissue stripping, leading to less postoperative pain and a faster postoperative recovery. As scientific evidence accumulates, the efficacy and safety of cervical endoscopic spine surgery are continually affirmed. Both anterior and posterior endoscopic approaches have surfaced as viable alternative treatments for various cervical spine pathologies. Newer techniques, such as endoscopic-assisted fusion, the anterior transcorporeal approach, and unilateral laminotomy for bilateral decompression, have been developed to enhance clinical outcomes and broaden surgical indications. Despite its advantages, this approach faces challenges, including a steep learning curve, increased radiation exposure for both surgeons and patients, and a relative limitation in addressing multi-level pathologies. However, the future of cervical endoscopic spine surgery is promising, with potential enhancements in clinical outcomes and safety on the horizon. This progress is fueled by integrating advanced imaging and navigation technologies, applying regional anesthesia for improved and facilitated postoperative recovery, and incorporating cutting-edge technologies, such as augmented reality. With these advancements, cervical endoscopic spine surgery is poised to broaden its scope in treating cervical spine pathologies while maintaining the benefits of minimized tissue damage and rapid recovery.

Anterior cervical osteotomy of diffuse idiopathic skeletal hyperostosis lesions with computer-assisted navigation surgery: A case report

Key Clinical Message

Diffuse idiopathic skeletal hyperostosis (DISH) involves spine ligament ossification. Computer-assisted navigation (CAN) effectively aids complex surgeries, such as anterior cervical osteotomy, to alleviate progressive DISH-related dysphagia.

Abstract

We describe a 68-year-old man with sudden onset dysphagia to both solids and liquids. Radiographic Imaging revealed DISH lesions from C2 down to the thoracic spine. The patient was successfully treated with CAN anterior osteotomy and resection of DISH lesions from C3-C6 and had complete symptom relief within 2 weeks post-operatively.