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.     

The role of reduction and internal fixation of Lisfranc fracture–dislocations: a systematic review of the literature

A systematic review of the literature was performed in order to evaluate the role of reduction and internal fixation in the management of Lisfranc joint fracture–dislocations. Articles were extracted from the Pubmed database and the retrieved reports were included in the study only if pre-specified eligibility criteria were fulfilled. Eleven articles were eligible for the final analysis, reporting data for the management of 257 patients. Injuries of the first three metatarsal rays were treated by closed reduction and internal fixation with screws in 16.3% of the patients, open reduction and internal fixation with screws in 66.5% and open reduction and internal fixation with Kirschner wires (K-wires) in 17.1% of the patients. The preferred method for the stabilisation of the fourth and fifth metatarsal rays was K-wires. Screw-related complications were common and were reported in 16.1% of the cases. The mean American Orthopaedic Foot and Ankle Society midfoot score was 78.1 points. Post-traumatic radiographic arthritis was reported in 49.6% of the patients, but only in 7.8% of them it was severe enough to warrant an arthrodesis. We conclude that open reduction and internal fixation of the first three metatarsal rays with screws is a reliable method for the management of Lisfranc injuries. This can be complemented by K-wires application in the fourth and fifth metatarsal rays if needed.     

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.     

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 cranio-cervical injuries: C1–C2 posterior cervical fusion and decompression

The occipitocervical junction allows for rotation and flexion-extension of the head rotation. Bony articulations between C1–C2 and the ligamentous complex are responsible for stability. Fractures or injuries to the ligamentous complex often requires operative management in order to restore stability. In this review, techniques for posterior cervical fusion and decompression are reviewed and include: fixation to C2, transarticular screw construct, screw-rod construct, occipital-cervical fusion, and posterior wiring. Complications and outcomes for each of the posterior techniques are described. While the primary focus is posterior approaches, anterior C1–C2 approach play a critical role in managing these injuries and is described briefly.     

Single-stage posterior vertebral column resection and internal fixation for old fracture–dislocations of thoracolumbar spine: a case series and systematic review

Purpose

To evaluate the efficacy of single-stage posterior vertebral column resection for old thoracolumbar fracture–dislocations with spinal cord injury.

Methods

From January 2007 to June 2013, twelve male patients (average age, 32.6 years; range 19–57 years) with old fracture–dislocations of the thoracolumbar spine and spinal cord injury underwent single-stage posterior vertebral column resection and internal fixation. All patients were assessed for relief of the pain and restoration of neurologic function. Postoperative Cobb angle was measured and bone graft fusion was evaluated by X-ray. A systematic review of 25 studies evaluating surgical management of thoracolumbar fractures with spinal cord injuries was also performed.

Results

From our case series, six of the nine patients with Frankel grade A had significant improvement in urination and defecation after surgery. The three patients with Frankel grades B and C had progression of 1–2 grades after surgery. Bony fusion was achieved and local back pain was relieved in all patients after surgery. From our systematic review of 25 studies, the majority of patients had improved back pain, the postoperative kyphotic angle was significantly reduced compared with pre-operative kyphotic angle.

Conclusion

Single-stage posterior vertebral column resection and internal fixation for old thoracolumbar fracture–dislocations is an ideal treatment allowing for thorough decompression, relief of pain, correction of deformities, and restoration of spinal stability.

Level of evidence

IV.

     

C1–C2 type Harms internal fixation for unstable C2 fracture in a 6-year-old boy: Case report

BackgroundDecision-making is often difficult in odontoid fracture in children.Case reportWe present the case of a 6-year-old boy who sustained cervical trauma on falling out of a tree. Initial cervical X-ray and CT-scan did not find any traumatic lesion. Three-week check-up revealed an unstable C2 fracture in the synchondrosis at the base of the odontoid bone, with anterior displacement (type IC on the classification of Hosalkar et al.), without neurological symptoms except for cervical pain and limitation of head rotation. MRI confirmed the absence of medullary lesion. The Harms technique was used to fix C1 and C2, using adult instrumentation without bone graft. Bone fusion was obtained at 8 months. Hardware was removed at 10 months. No complications were reported.ConclusionsPosterior internal fixation for unstable C2 fractures in children can be effective and relatively safe.     

Clinical and radiologic outcome of laminar screw at C2 and C7 for posterior instrumentation—review of 25 cases and comparison of C2 and C7 intralaminar screw fixation

BackgroundThe aim of this study is 2-fold: to analyze a clinical case series in which we used laminar screws for cervical posterior instrumentation and to describe the difference between C2 and C7 laminar screws in terms of technique and anatomy.MethodsData were obtained from 25 patients who underwent cervical posterior fixation with intralaminar screws at C2 or C7. C2 intralaminar screw instrumentation was used for 7 patients requiring occipitocervical fixation (basilar invagination [3 patients], C1 unstable bursting fracture [1 patient], C1-C2 instability with occipital assimilation [2 patients], and dystopic os odontoideum [1 patient]), 13 patients with C1-C2 instability, 1 patient with C2-C3 subluxation, and 4 patients undergoing C7 fixation due to pseudoarthrosis or cervical instability after trauma. A total of 34 laminar screws were placed including 1 thoracic laminar screw, and the patients were assessed both clinically and radiographically.ResultsThere were no instances where a screw violated the spinal canal nor any hardware fractures noted during the follow-up period. As for perioperative complications, there were 2 cases of postoperative wound infection, 1 case of dural laceration during dissection, and 2 cases of partial dorsal laminar breach. However, there was no neurologic compromise in any of the cases. The fusion success rate was 100%.ConclusionThese preliminary results support the use of intralaminar screws for posterior instrumentation at C2 and C7.     

Mini-open approach combined with percutaneous transarticular screw fixation for C1–C2 fusion

This paper describes a limited exposure for posterior C1–C2 arthrodesis aided by percutaneous transarticular fixation. The purpose of this study was to report the fusion rate using the aforementioned method. Fifty-seven patients (54 females and three males) with C1–C2 instability due to rheumatoid disease constituted the material of this study. The exposure was restricted to C0–C3 levels. The drilling and insertion of the screws was done through two mini stab wounds. A special sleeve and screwdriver were developed to facilitate this step. An autogenous iliac bone graft was fixed between the decorticated posterior arch of the atlas and the lamina of the axis vertebra. The mean of the atlantodental interval decreased from 8.5 mm (SD 2.3 mm) to 2.6 mm (SD 0.6 mm) at the immediate postoperative periods and reached 2.7 mm (SD 0.7 mm) after a mean follow-up of 30.4 months (SD 5.6 months). Malposition of the screws was observed in two patients and warranted a second operation in one. Fusion was evident in 98% of the cases. Percutaneous insertion of the screws in posterior C1–C2 transarticular fixation reduces the size of the exposure and the surgical trauma to the cervical segments below the fixation.     

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.     

A “Modern” posterior approach: “The Back Is Back”

In recent years the direct anterior approach (DAA) to total hip arthroplasty has gained in popularity. This increased interest in the DAA took place at a time when surgeons using a traditional posterior approach were struggling with dislocation risks and slowed recovery due to now outdated, and largely abandoned, techniques combined with older style implants. However, at the same time that the DAA gained in popularity, the standard posterior approach was also being modified. It has been adapted to work with newer instrumentation and modern cementless implants which also offer an expanded array of sizing and dimensioning versatility. We present a contemporary, iliotibial band sparing, minimally invasive posterior approach that we believe achieves the same degree of soft tissue preservation, with similar early recovery benefits as compared to the DAA. This highly modified posterior approach offers a lower risk profile and the potential for stepwise adoption and a surgeon controlled learning curve.     

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.