Anterior reduction and C1-ring osteosynthesis with Jefferson-fracture reduction plate (JeRP) via transoral approach for unstable atlas fractures

Background To introduce a novel transoral instrumentation in the treatment of unstable fractures of the atlas. Methods From January 2008 to May 2018, 22 patients with unstable C1 fractures who received Jefferson-fracture reduction plate (JeRP) via transoral approach were retrospectively analyzed. The case history and the radiographs before and after surgery were noted. The type of fracture, the reduction of the fracture, and position of the internal fixation were assessed through preoperative and postoperative CT scans. Results All 22 patients successfully underwent anterior C1-ring osteosynthesis using the JeRP system, with a follow-up of 26.84 ± 9.23 months. Among them, 9 patients had transverse atlantal ligament (TAL) injury, including 3 in Dickman type I and 6 in type II. The preoperative lateral mass displacement (LMD) decreased from 7.13 ± 1.46 mm to 1.02 ± 0.65 mm after the operation. Bone union was achieved in all patients without implant failure or loss of reduction. There were no surgery-related complications, such as wound infection, neurological deficit, or vertebral artery injury. However, atlantoaxial dislocation occurred in 3 patients with Dickman type I TAL injury 3 months postoperatively without any neurological symptoms or neck pain. Conclusions Transoral C1-ring osteosynthesis with JeRP is an effective surgical strategy to treat unstable atlas fractures with a safe, direct, and satisfactory reduction. The primary indication for the JeRP system is an unstable fracture (Gehweiler type I/III) or/ and TAL injury (Dickman type II).

Anterior Reduction and C1-ring Osteosynthesis With Jefferson-fracture Reduction Plate (JeRP) via Transoral Approach for Unstable Atlas Fractures

Objective:To introduce a novel transoral instrumentation in the treatment of unstable fractures of atlas.Methods: From January 2008 to May 2018, 22 patients with unstable C1 fractures were retrospective analyzed, who received Jefferson-fracture reduction plate (JeRP) via transoral approach. The case history and the radiographs before and after surgery were noted. The type of fracture, the reduction of the fracture and position of the internal fixation were assessed by preoperative and postoperative CT scans.RESULTS: All 22 patients successfully underwent anterior C1-ring osteosynthesis using JeRP system, with a follow-up of 26.84±9.23 months. Among them, 9 patients had transverse atlantal ligament (TAL) injury, including 3 in Dickman type I and 6 in type II. The preoperative lateral mass displacement (LMD) decreased from 7.13±7.08 mm to 1.02±0.65 mm after operation. Bone union was achieved in all patients without implant failure or loss of reduction. There were no surgery-related complications, such as wound infection, neurological deficit, or vertebral artery injury. However, 3 patients with Dickman type I TAL injury occured atlantoaxial dislocation 3 months postoperatively without any neurological symptoms or neck pain.CONCLUSIONS: Transoral C1-ring osteosynthesis with JeRP is an effective surgical strategy of unstable atlas fractures, achieving direct and satisfactory reduction safely. The primary indication for JeRP system is an unstable fracture (Gehweiler type I/III) or/ and TAL injury (Dickman type II).

Interobserver reliability of the Gehweiler classification and treatment strategies of isolated atlas fractures: an internet-based multicenter survey among spine surgeons

Purpose Atlas (C1) fractures are commonly rated according to the Gehweiler classification, but literature on its reliability is scarce. In addition, evaluation of fracture stability and choosing the most appropriate treatment regime for C1-injuries are challenging. This study aimed to investigate the interobserver reliability of the Gehweiler classification and to identify whether evaluation of fracture stability as well as the treatment of C1-fractures are consistent among spine surgeons. Methods Computed tomography images of 34 C1-fractures and case-specific information were presented to six experienced spine surgeons. C1-fractures were graded according to the Gehweiler classification, and the suggested treatment regime was recorded in a questionnaire. For data analyses, SPSS was used, and interobserver reliability was calculated using Fleiss’ kappa (κ) statistics. Results We observed a moderate reliability for the Gehweiler classification (κ = 0.50), the evaluation of fracture stability (κ = 0.50), and whether a surgical or non-surgical therapy was indicated (κ = 0.53). Type 1, 2, 3a, and 5 fractures were rated stable and treated non-surgically. Type 3b fractures were rated unstable in 86.7% of cases and treated by surgery in 90% of cases. Atlas osteosynthesis was most frequently recommended (65.4%). Overall, 25.8% of type 4 fractures were rated unstable, and surgery was favoured in 25.8%. Conclusion We found a moderate reliability for the Gehweiler classification and for the evaluation of fracture stability. In particular, diverging treatment strategies for type 3b fractures emphasise the necessity of further clinical and biomechanical investigations to determine the optimal treatment of unstable C1-fractures.

3D-Printed Screw-Rod Auxiliary System for Unstable Atlas Fractures: A Retrospective Analysis

Objective To develop and validate a 3D-printed screw-rod auxiliary system for unstable atlas fractures.Methods Fourteen patients who underwent occipitocervical fusion with the 3D-printed screw-rod auxiliary system enrolled in our hospital from 2017 to 2019 were reviewed. The operation time, blood loss and radiation times during the operation were recorded. The maximum fracture displacement values pre- and post-operation were measured based on CT imaging. All screw grades were evaluated after surgery. The O-C2 angle and OCI angle pre-operation, post-operation and at the last follow-up were measured. The dysphagia scale 3 and 12 months after surgery and the NDI 3 and 12 months after surgery were assessed.Results The average surgery time, average blood loss and average radiation times for the 14 patients were 112.14 minutes, 171.43 ml and 5.07 times, respectively. There was a significant difference in maximum fracture displacement between pre- and post-operation values (P<0.05). A total of 56 screws were inserted; 3 screws were classified as grade 1, and the others were classified as grade 0. There was a significant difference in the O-C2 and OCI angles from pre-operation values to values 3 days after the operation (P=0.002, P<0.05); there was no significant difference in the O-C2 or OCI angle from 3 days after the operation to the last follow-up (P=0.079; P=0.201). The dysphagia scales of two patients were assessed as mild 3 months after surgery, and the others were assessed as normal. All patients’ dysphagia scores returned to normal 12 months after surgery. The average NDI and average neck VAS scores 12 months after surgery were 2.53 and 8.41, respectively.Conclusion It is clinically feasible with the assistance of a screw-rod auxiliary system to perform occipitocervical fusion for unstable atlas fractures. This novel technique can objectively restore the occipitocervical angle of patients, and there are few postoperative complications.

Motion-preserving treatment of unstable atlas fracture: transoral anterior C1-ring osteosynthesis using a laminoplasty plate

Background C1-ring osteosynthesis is a valid alternative to posterior C1–C2 or C0–C2 fusion to preserve important C1–C2 motion in the treatment of unstable atlas fractures. Nevertheless, the fixation instruments used in current studies for transoral anterior C1-ring osteosynthesis were not suitable for anterior anatomy of the atlas or did not have reduction mechanism. We therefore present this report to investigate preliminary clinical effects of transoral anterior C1-ring osteosynthesis using a laminoplasty plate in unstable atlas fractures. Methods From January 2014 to December 2017, 13 patients with unstable atlas fractures were retrospectively reviewed. All patients were treated with transoral anterior C1-ring osteosynthesis using a laminoplasty plate. Pre- and postoperative images were obtained to assess reduction of the fracture, internal fixation placement, and bone union. Neurological function, range of motion, and pain levels were evaluated clinically on follow-up. Results The surgeries were successfully performed in all cases. The average follow-up duration was 16.6 ± 4.4 months (range 12–24 months). One patient suffered screw loosening after operation and underwent replacement operation subsequently. Satisfactory clinical outcomes were achieved in all patients with ideal fracture reduction, reliable plate placement, well-preserved range of motion, and neck pain alleviation. All patients achieved bone union of fractures without loss of reduction or implant failure or C1–C2 instability during the follow-up. No vascular or neurological complication was noted during the operation and follow-up. Conclusions Transoral anterior C1-ring osteosynthesis using a laminoplasty plate is a effective surgical treatment for unstable atlas fractures. This technique has a ingenious reduction mechanism, and can provide satisfactory bone union and preservation of C1–C2 motion.

Epidemiology and management of atlas fractures

Purpose The purpose of this study was to gain new insights into the epidemiologic characteristics of patients with atlas fractures and to retrospectively evaluate complication rates after surgical and non-surgical treatment. Methods In a retrospective study, consecutive patients diagnosed with a fracture of the atlas between 01/2008 and 07/2018 were analyzed. Data on epidemiology, concomitant injuries, fracture patterns and complications were obtained by chart and imaging review. Results In total, 189 patients (mean age 72 years, SD 19; 57.1% male) were treated. The most frequent trauma mechanism was a low-energy trauma (59.8%). A concomitant injury of the cervical spine was found in 59.8%, a combined C1/C2 injury in 56.6% and a concomitant fracture of the thoraco-lumbar spine in 15.4%. When classified according to Gehweiler, there were: 23.3% type 1, 22.2% type 2, 32.8% type 3, 19.0% type 4 and 1.1% type 5. Treatment of isolated atlas fractures (n = 67) consisted of non-operative management in 67.1%, halo fixation in 6.0% and open surgical treatment in 26.9%. In patients with combined injuries, the therapy was essentially dictated by the concomitant subaxial cervical injuries. Conclusions Atlas fractures occurred mainly in elderly people and in the majority of the cases were associated with other injuries of the head and spine. Most atlas fractures were treated conservatively. However, surgical treatment has become a safe and valid option in unstable fracture patterns involving the anterior and posterior arch (type 3) or those involving the articular surfaces (type 4). Level of evidence IV (Retrospective cohort study). Graphic abstract These slides can be retrieved under Electronic Supplementary Material.