Bilateral C1 laminar hooks combined with C2 pedicle screws fixation for treatment of C1–C2 instability not suitable for placement of transarticular screws

The study design described here is a posterior C1–C2 fusion technique composed of bilateral C1 hooks and C2 pedicle screws. In addition, the clinical results of using this method on 13 patients with C1–C2 instability are reported. The objectives are to introduce a new technique for posterior C1–C2 fusion and to evaluate the clinical outcome of using it to treat C1–C2 instability. From October 2006 to August 2008, 13 patients (9 men and 4 women) with C1–C2 instability were included in this study: 3 had acute odontoid fractures, 4 had obsolete odontoid fractures, 4 had os odontoideum and 2 had traumatic rupture of the transverse ligament. All patients underwent posterior atlantoaxial fixation with bilateral C1 hooks and C2 pedicle screws. The mean follow-up duration was 25 months (range 13–30 months). Each patient underwent a complete cervical radiograph series, including anterior–posterior, lateral, and flexion–extension views, and a computed tomographic scan. The clinical course was evaluated according to the Frankel grading system. No clinically manifested injury of the nerve structures or the vertebral artery was observed in any of these cases. Five patients with neurological symptoms showed significant improvement in neurological function postoperatively. Bony fusion and construction stability were observed in all 13 patients (100%) on their follow-up radiographs, and no instrument failure was observed. Bilateral C1 hooks combined with C2 pedicle screws can be used as an alternative treatment method for C1–C2 dislocation, especially in cases not suitable for the use of transarticular screws. The clinical follow-up shows that this technique is a safe and effective method of treatment.     

C1–2 transarticular screws combined with C1 laminar hooks fixation: a modified posterior atlantoaxial fixation technique and outcome in 72 patients

Purpose

To retrospectively evaluate the outcome of C1–2 transarticular screws combined with C1 laminar hooks fixation.

Methods

All patients underwent atlantoaxial fixation during a 5-year period. The surgical technique and treatment procedures were intensively reviewed and clinical symptoms, neurological function and imaging appearance were retrospectively evaluated.

Results

The clinical and radiology follow-up indicated a stable arthrodesis and clinical relief from symptoms for all patients. All patients with neurological defects improved an average of 1.33 grade at their most recent clinical assessment, P < 0.05; their average admission ASIA motor score, pin prick score and light touch score improved to an average follow-up ASIA score of 99.80 (99.83 ± 0.38), 111.83 (111.83 ± 0.45), and 111.89 (111.89 ± 0.32), respectively. No neurovascular impairment and case of implant failure were observed.

Conclusions

The C1–2 transarticular screws combined with C1 laminar hooks fixation is a reliable technique for atlantoaxial instability.     

C2 translaminar screw as the optimal choice for atlantoaxial dislocation with C2–C3 congenital fusion

Objective and importance  

The entry point and trajectory are very important for transarticular screw (TAS) and C2 pedicle screw (PDS) plantation. When the physical size is not large enough for the screw passing through, an accurate entry point is the most important point for successful screw insertion without vertebral artery (VA) injury and spinal cord injury. Once the laminas of C2 and C3 are fused, the normal anatomic mark might disappear and the insertion point would be hard to find. As a result, the complication of TAS or PDS implantation increases rapidly. We used C2 translaminar screws (TLSs) with C1 lateral mass screws as the optimal fixation for atlantoaxial dislocation in order to reduce the risk of VA injury and spinal cord injury.     

Posterior C1–C2 screw and rod instrument for reduction and fixation of basilar invagination with atlantoaxial dislocation

Purpose

To report the surgical technique and preliminary clinical results for the treatment of basilar invagination (BI) with atlantoaxial dislocation (AAD) by posterior C1–C2 pedicle screw and rod instrument.

Methods

Between July 2012 and August 2013, 33 patients who had BI with AAD underwent surgery at our institution. Pre and postoperative three-dimensional computed tomographic (CT) scans were performed to assess the degree of dislocation. Magnetic resonance (MR) imaging was used to evaluate the compression of the medulla oblongata. For all patients, reduction of the AAD was conducted by two steps: fastening nuts and rods was performed to achieve the horizontal reduction. Distraction between C1 and C2 screws was performed to obtain the vertical reduction.

Results

No neurovascular injury occurred during surgery. Follow-up ranged from 6 to 15 months (mean 10.38 months) in 32 patients. Post-operative three-dimensional CT showed that complete horizontal reduction was obtained in 30/33 (90.9 %), and complete vertical reduction was obtained in 31/33 (93.9 %). The repeated three-dimensional CT and MR image demonstrated that bony fusion and the decompression of the medulla oblongata were obtained in all patients. Clinical symptoms improved significantly 3 months after surgery.

Conclusions

This C1–C2 pedicle screw and rod instrument is a promising technique for the treatment of BI with AAD.     

Management of hangman’s fracture with percutaneous transpedicular screw fixation

Purpose

This study describes a percutaneous technique for C2 transpedicular screw fixation and evaluates its safety and efficacy in the treatment of patients with hangman’s fracture.

Methods

Ten patients with hangman’s fracture were treated by percutaneous C2 transpedicular screw fixation. There are six males and four females, who were, based on the classification of Levine and Edwards, sorted as follows: type I fracture, three cases; type II, five cases; type IIa, two cases. The causes of injury were road traffic accident in six patients and falling injury in four patients. Other associated lesions included rib fractures (7 patients), head injuries (4 patients), and fractures of extremities (6 patients).

Results

The new technique was performed successfully in all cases. The average operation time was 98 min (range 60–130 min) and the estimated blood loss was 25 ml (range 15–40 ml). No complications such as vascular or neural structures injuries were found intraoperatively. Postoperative CT scans demonstrated that 17 (85 %) of 20 screws were placed satisfactorily, and 3 (15 %) screws showed perforations of the pedicle wall (<2 mm). These patients were asymptomatic and no further intervention was required postoperatively. After 8–25 months follow-up (mean 15.3 months), solid fusion was demonstrated by computed tomography. All cases got well-sagittal alignment and no angulation or dislocation was found at the segment of C2–C3. There was no loss of fixation. Clinical examination showed a full range of motion in the neck in all patients.

Conclusions

The fluoroscopically assisted percutaneous C2 transpedicular screw fixation method is a technically feasible and minimally invasive technique for hangman’s fracture.     

Is the technique of posterior transarticular screw fixation suitable for rheumatoid atlanto-axial subluxation?

The rheumatoid patient with atlanto-axial subluxation presents a major challenge to the spinal surgeon, owing to the poor wound healing and bone quality. Traditional wiring techniques are associated with a high complication and failure rate. Posterior transarticular screw fixation of the atlanto-axial joint offers a credible alternative and when combined with a Gallie construct offers immediate true 3-point stability. It is, however, a difficult and demanding technique which carries a risk of vertebral artery, cranial nerve and spinal cord damage. The question that arises therefore is "Do the improved stability rates afforded by this technique really justify the risks of arterial and neurological damage?" To date there have been no studies of this technique dealing solely with the rheumatoid patient, with most reports dealing with a heterogeneous patient population, mainly trauma-related cases. The purpose of this report is to analyse critically our results with particular reference to the complications that we have encountered and the technical reasons for their occurrence. We analysed the clinical and radiological data of 38 rheumatoid patients (six males: 32 females, mean age of 54 years) with atlanto-axial subluxation who underwent transarticular screw fixation. Our analysis centred on screw malposition and complications. Parametric and non parametric statistical analysis was performed. Significance was accepted at the 5% level (p < 0.05). Our analysis revealed that three vertebral arteries were damaged. Two of these were recognized at the time of surgery, with the remaining case only suspected following postoperative CT to assess screw positioning. Vertebral artery occlusion was subsequently confirmed by angiography. All three patients were asymptomatic from their arterial injury. There was only one neurological complication in this series, and this was caused by a high screw, which damaged the hypoglossal nerve with a temporary nerve palsy ensuing. Four screws broke, all were made of titanium, but more importantly, all were also associated with contralateral screw malposition. Stability was achieved in 95% of cases overall. The high stability rates afforded by this technique do appear to justify the inherent risks of this procedure. If unilateral screw fixation only is achieved, we would recommend a period of halo immobilization until osseous union occurs.     

Modified technique for C1–2 screw-rod fixation and fusion using autogenous bicortical iliac crest graft

Introduction  

Various techniques have been described for posterior atlantoaxial fusion. Sublaminar passage of the wire/cable is cumbersome with a risk of spinal cord injury. Packing morselized bone grafts into the C1–2 facet joints may be difficult and it may cause massive bleeding and neuropathic pain or posterior scalp numbness postoperatively. We introduce a modified method by using C1–2 screw-rod fixation (SRF) to compress a structural iliac bone graft between the posterior elements of C1 and C2 without supplemental wiring construct.     

Circumferential fusion: a comparative analysis between anterior lumbar interbody fusion with posterior pedicle screw fixation and transforaminal lumbar interbody fusion for L5–S1 isthmic spondylolisthesis

Background Context

Transforaminal lumbar interbody fusion (TLIF) or anterior lumbar interbody fusion with percutaneous pedicle screws (ALIFPS) offer significantly higher radiographic fusion rates than other fusion techniques for L5–S1 isthmic spondylolisthesis (IS). As it stands, there is a relative paucity of comparative data of the two techniques.

Efficacy of TiRobot-assisted minimally invasive percutaneous screw fixation for pelvic fractures北大核心CSCD

Objective To investigate the clinical efficacy of TiRobot-assisted minimally invasive percutaneous screw fixation for pelvic fractures. Methods The clinical data of 44 patients with pelvic fracture were retrospectively analyzed who had undergone TiRobot-assisted minimally invasive percutaneous screw fixation from May 2018 to April 2021 at Department of Orthopedic Traumatology, The First Hospital of Jilin University. There were 30 males and 14 females, aged from 11 to 78 years (average, 40. 6 years). According to the Tile classification, there were 20 type CI fractures, 23 type C2 fractures and one type C3 fracture. The time from injury to operation averaged 8. 2 days (from 1 to 41 days). The minimally invasive percutaneous screw fixation was assisted by the orthopaedic TiRobot in all patients. Operation time, fluoroscopy time, reduction quality, complications and functional recovery at the final follow-up were recorded and analyzed. Results A total of 96 screws were implanted in this cohort. The total fluoroscopy time ranged from 17 to 66 s, with an average of 17. 8 s for each single screw. The operation time ranged from 50 to 355 min, averaging 179. 7 min. According to the Matta criteria, the reduction quality was rated as excellent in 36 cases, as good in 5 and as fair in 3, yielding an excellent and good rate of 93. 2% (41/44). All the 44 patients were followed up for 6 to 42 months (average, 20. 4 months). The fracture healing time ranged from 2 to 6 months, averaging 3. 3 months. The Majeed scores at the final follow-up ranged from 51 to 100 points (average, 83. 7 points); there were 28 excellent, 8 good, 7 fair and one poor cases, giving an excellent to good rate of 81. 8% (36/44). Follow-up found no such complications as iatrogenic neurovascular injury, incision infection, malunion, implant loosening or fracture re-displacement in all the 44 patients. Conclusion TiRobot-assisted minimally invasive internal fixation can result in fine clinical efficacy for pelvic fractures, showing advantages of accuracy, minimal invasion and safety. © The Author(s) 2023.     

Morphological and clinical feasibility of C3 pedicle screw instrumentation in patients with congenital C2–3 fusion

Purpose

Congenital C2–3 fusion (C2–3CF) is often involved in patients with atlantoaxial dislocation, and posterior occipitocervical fixation surgery is usually required. Hypoplasia of C2 pedicle is common in such patients, making C2 pedicle screws (PS) instrumentation inapplicable. Because of congenital fusion, C3PS instrumentation would be an ideal alternative for it will not sacrifice an additional motion segment; however, the morphological and clinical feasibility has not been previously reported.

Methods

We included 42 C2–3CF patients to this study and evaluated pedicle trajectories of C2 and C3 using a three-dimensional CT. Clinical applications of C3PS instrumentation were evaluated and followed.

Results

Among the 42 patients, 23 (54.8 %) and 8 (19.0 %) had C2 and C3 pedicle trajectory diameters <4.0 mm, respectively. The bisection line of the fused C2–3 lamina was used to represent the superior border of C3 articular mass; the entry point of C3 pedicle was located at 3 mm inferior to the assumed superior border and 3.2 mm medial to the lateral border. Bilateral C3PS instrumentations were successfully adopted in 22 patients. No spinal cord or vertebral artery injury occurred; postoperative CT showed a trajectory breach rate of 17.4 % for C3PS. After mean of 3.6-year follow-up, no implant failure was documented.

Conclusions

C3PS instrumentation is morphologically and clinically feasible for a large proportion of patients with C2–3CF and can serve as another reliable alternative for C2PS instrumentation. Preoperative evaluation of pedicle trajectory of C2–3CF with three-dimensional CT is highly valuable in the choice of proper fixation methods.     

Miniarthrotomy assisted percutaneous screw fixation for displaced medial malleolus fractures – A novel technique

Aim

To describe here a technique of miniarthrotomy assisted percutaneous screw insertion for displaced Herscovici type B and C medial malleolar fractures.

Method

Incision was made centred over the superomedial angle of the ankle mortise, about half a cm medial to tibialis anterior. Arthrotomy was done and reduction obtained. Percuntaneously, two 4 mm cancellous cannulated screws were inserted through medial malleolus.

Results and conclusion

This approach allows direct visualization of reduction, removal of entrapped soft tissue and preservation of saphenous vein and nerve.     

Posterior realignment of irreducible atlantoaxial dislocation with C1–C2 screw and rod system: a technique of direct reduction and fixation

Background contextTreatment of chronic and irreducible atlantoaxial dislocation (AAD) with ventral compression is challenging for surgeons. The main procedures are occipitocervical/C1–C2 fusion after transoral odontoidectomy or release of the periodontoid tissues. These surgical procedures, which are performed simultaneously or intermittently, have many disadvantages that may discount their effectiveness. Therefore, a more effective way to achieve surgical reduction and to keep solid stability with only a single procedure is needed.PurposeWe describe a technique to reduce chronic and irreducible AAD with C1 lateral mass and C2 pedicle screw and rod system.Study designThis was a retrospective case series.Patient sampleOur sample comprised 26 patients (9 men and 17 women) with irreducible AAD who ranged in age from 15 to 54 years (mean, 35 years).Outcome measuresPatients' neurologic status was evaluated with the Japanese Orthopedic Association (JOA) scale.MethodsTwenty-six symptomatic patients underwent posterior realignment and reduction through the C1 lateral mass and C2 pedicle screw and rod system. The proposed mechanism of reduction is that the implanted screws and rods between C1 and C2 acting as a lever system drew C1 backward and pushed C2 downward and forward after removing circumambient obstruction and scars and thoroughly releasing the facet joints. The preoperative and postoperative JOA score, the extent of reduction, and the conditions of C1–C2 bony fusion were examined.ResultsNo neurovascular injury occurred during surgery. Follow-up ranged from 6 to 40 months (mean 20.7 months). Radiographic evaluation showed that solid bony fusion was achieved in all patients, and that complete reduction was attained in 18 patients and partial reduction (>60% reduction) in 8 patients. The mean postoperative JOA score at last follow-up was 15.7, compared with the preoperative score of 12.1 (p<.01).ConclusionsThis C1–C2 screw and rod system provides reliable stability and sufficient reduction of the anatomic malalignment at the craniovertebral junction and meanwhile retains the mobility of atlanto-occipital joints in the treatment of chronic and irreducible AAD. Sophisticated skills, thorough release of the facet joints, and intraoperative protection of the vertebral artery are key points to accomplish this technique.     

Modification of Wright’s technique for C2 translaminar screw fixation: technical note

Purpose  

To describe a modification of Wright’s technique for C2 translaminar screw fixation.     

Less invasive reduction and fusion of fresh A2 and A3 traumatic L1–L4 fractures with a novel vertebral body augmentation implant and short pedicle screw fixation and fusion

The aim of this clinical study was to report on the efficacy in reduction and safety in PMMA leakage of a novel vertebral augmentation technique with PEEK and PMMA, together with pedicle screws in the treatment of fresh vertebral fractures in young adults. Twenty consecutive young adults aged 45 ± 11 years with fresh burst A₃/AO or severely compressed A₂/AO fractures underwent via a less invasive posterior approach one-staged reduction with a novel augmentation implant and PMMA plus 3-vertebrae pedicle screw fixation and fusion. Radiologic parameters as segmental kyphosis (SKA), anterior (AVBHr) and posterior vertebral body height ratio (PVBHr), spinal canal encroachment (SCE), cement leakage and functional parameters as VAS, SF-36 were measured pre- and post-operatively. Hybrid construct restored AVBHr (P < 0.000), PVBHr (P = 0.02), SKA (P = 0.015), SCE (P = 0.002) without loss of correction at an average follow-up of 17 months. PMMA leakage occurred in 3 patients (3 vertebrae) either anteriorly to the fractured vertebral body or to the adjacent disc, but in no case to the spinal canal. Two pedicle screws were malpositioned (one medially, one laterally to the pedicle at the fracture level) without neurologic sequelae. Solid posterolateral spinal fusion occurred 8–10 months post-operatively. Pre-operative VAS and SF-36 scores improved post-operatively significantly. This study showed that this novel vertebral augmentation technique using PEEK implant and PMMA reduces and stabilizes via less invasive technique A₂ and A₃ vertebral fractures without loss of correction and leakage to the spinal canal.     

Percutaneous short-segment pedicle screw placement without fusion in the treatment of thoracolumbar burst fractures: is it effective?: comparative study with open short-segment pedicle screw fixation with posterolateral fusion

Background

Since introduction of the pedicle screw-rod system, short-segment pedicle screw fixation has been widely adopted for thoracolumbar burst fractures (TLBF). Recently, the percutaneous pedicle screw fixation (PPSF) systems have been introduced in spinal surgery; and it has become a popularly used method for the treatment of degenerative spinal disease. However, there are few clinical reports concerning the efficacy of PPSF without fusion in treatment of TLBF. The purpose of this study was to determine the efficacy and safety of short-segment PPSF without fusion in comparison to open short-segment pedicle screw fixation with bony fusion in treatment of TLBF.

Methods

This study included 59 patients, who underwent either percutaneous (n?=?32) or open (n?=?27) short-segment pedicle screw fixation for stabilization of TLBF between December 2003 and October 2009. Radiographs were obtained before surgery, immediately after surgery, and at the final follow-up for assessment of the restoration of the spinal column. For radiologic parameters, Cobb angle, vertebral wedge angle, and vertebral body compression ratio were assessed on a lateral thoracolumbar radiograph. For patient’s pain and functional assessment, the visual analogue scale (VAS), the Frankel grading system, and Low Back Outcome Score (LBOS) were measured. Operation time, and the amount of intraoperative bleeding loss were also evaluated.

Findings

In both groups, regional kyphosis (Cobb angle) showed significant improvement immediately after surgery, which was maintained until the last follow up, compared with preoperative regional kyphosis. Postoperative correction loss showed no significant difference between the two groups at the final follow-up. In the percutaneous surgery group, there were significant declines of intraoperative blood loss, and operation time compared with the open surgery group. Clinical results showed that the percutaneous surgery group had a lower VAS score and a better LBOS at three months and six months after surgery; however, the outcomes were similar in the last follow-up.

Conclusions

Both open and percutaneous short-segment pedicle fixation were safe and effective for treatment of TLBF. Although both groups showed favorable clinical and radiologic outcomes at the final follow-up, PPSF without bone graft provided earlier pain relief and functional improvement, compared with open TPSF with posterolateral bony fusion. Despite several shortcomings in this study, the result suggests that ongoing use of PPSF is recommended for the treatment of TLBF.     

Risk of vertebral artery injury: comparison between C1–C2 transarticular and C2 pedicle screws

Background contextTo our knowledge, no large series comparing the risk of vertebral artery injury by C1–C2 transarticular screw versus C2 pedicle screw have been published. In addition, no comparative studies have been performed on those with a high-riding vertebral artery and/or a narrow pedicle who are thought to be at higher risk than those with normal anatomy.PurposeTo compare the risk of vertebral artery injury by C1–C2 transarticular screw versus C2 pedicle screw in an overall patient population and subsets of patients with a high-riding vertebral artery and a narrow pedicle using computed tomography (CT) scan images and three-dimensional (3D) screw trajectory software.Study designRadiographic analysis using CT scans.Patient sampleComputed tomography scans of 269 consecutive patients, for a total of 538 potential screw insertion sites for each type of screw.Outcome measuresCortical perforation into the vertebral artery groove of C2 by a screw.MethodsWe simulated the placement of 4.0 mm transarticular and pedicle screws using 1-mm-sliced CT scans and 3D screw trajectory software. We then compared the frequency of C2 vertebral artery groove violation by the two different fixation methods. This was done in the overall patient population, in the subset of those with a high-riding vertebral artery (defined as an isthmus height ≤5 mm or internal height ≤2 mm on sagittal images) and with a narrow pedicle (defined as a pedicle width ≤4 mm on axial images).ResultsThere were 78 high-riding vertebral arteries (14.5%) and 51 narrow pedicles (9.5%). Most (82%) of the narrow pedicles had a concurrent high-riding vertebral artery, whereas only 54% of the high-riding vertebral arteries had a concurrent narrow pedicle. Overall, 9.5% of transarticular and 8.0% of pedicle screws violated the C2 vertebral artery groove without a significant difference between the two types of screws (p=.17). Among those with a high-riding vertebral artery, vertebral artery groove violation was significantly lower (p=.02) with pedicle (49%) than with transarticular (63%) screws. Among those with a narrow pedicle, vertebral artery groove violation was high in both groups (71% with transarticular and 76% with pedicle screws) but without a significant difference between the two groups (p=.55).ConclusionsOverall, neither technique has more inherent anatomic risk of vertebral artery injury. However, in the presence of a high-riding vertebral artery, placement of a pedicle screw is significantly safer than the placement of a transarticular screw. Narrow pedicles, which might be anticipated to lead to higher risk for a pedicle screw than a transarticular screw, did not result in a significant difference because most patients (82%) with narrow pedicles had a concurrent high-riding vertebral artery that also increased the risk with a transarticular screw. Except in case of a high-riding vertebral artery, our results suggest that the surgeon can opt for either technique and expect similar anatomic risks of vertebral artery injury.