Rigid occipitocervical fixation: indications, outcomes, and complications in the modern era

Rigid occipitocervical fixation- indications, outcomes, and complications in the modern era

J Neurosurg Spine 18:333–339, 2013

Over the past 40 years, various methods and instrumentation types have been developed for occipitocervical fixation (OCF) in the management of occipitocervical instability. This study reports indications, outcomes, and complications with rigid OCF using screw-rod and screw-plate instrumentation, which has comparatively less long-term data.

Methods. A prospectively maintained database identified 100 consecutive patients who underwent rigid OCF in a single unit over a period of 13 years. Patient demographics, clinical indications, pre- and postoperative radiographic findings, neck disability indices (NDIs), myelopathy disability indices (MDIs), visual analog scale (VAS) scores, and Ranawat scores were recorded. Complications including instrumentation failure were also documented.

Results. Underlying etiologies included rheumatoid arthritis (RA; 41%), tumor (16%), trauma (15%), congenital etiologies (14%), metabolic (6%) and inflammatory (6%) conditions, and infection (2%). The pre- and postoperative MDI and VAS scores for neck pain showed significant improvements in the RA group (MDI 64.5% vs 42.5%, p = 0.02; mean VAS 7.5 of 10 vs 3.7 of 10, p < 0.001). Improvements in MDI and NDI outcome measures were also seen in the trauma and tumor categories. Overall, there were 4 cases of instrumentation failure; all included broken rods in the stress riser region of occipitocervical rod curvature, and 1 patient also had occipital plate screw pullout. Other complications included 5 wound infections requiring wound washout, 1 vertebral artery injury (no clinical sequelae), and 1 perioperative death due to myocardial infarction.

Conclusions. Rigid OCF is a safe and effective method of managing occipitocervical instability due to a variety of causes. Outcome measures are favorable, and patients with chronically debilitating diseases such as RA may benefit in terms of improvements in neurological deficit and neck pain. The complication profile is comparable to that reported in other series of OCF in the literature, as well as to the previously used semirigid type of rod/sublaminar wire fixation.

Is inclusion of the occiput necessary in fusion for C1–2 instability in rheumatoid arthritis?

Is inclusion of the occiput necessary in fusion for C1–2 instability in rheumatoid arthritis?

J Neurosurg Spine 18:50–56, 2013

The atlantoaxial joint is the location most and earliest affected in patients with rheumatoid arthritis (RA). In longstanding disease, ligamentous and osseous destruction can progress and involve all cervical segments. If surgical intervention is necessary, some prefer, to be safe, undertaking fusion to the occiput, whereas others advocate 1-level fusion of C1–2. Sparing the occiput (Oc)–C1 segment would allow retention of a considerable amount of physiological range of motion and seems beneficial against subaxial overload. Previous clinical studies on this topic have provided only nonspecific data after short-term follow-up, rendering a segment-sparing approach questionable. The purpose of the present investigation was to assess long-term progression of inflammatory or degenerative destruction in the Oc–C1 segment after isolated C1–2 fusion for RA.

Methods. In a series of 113 consecutive patients with RA-related destruction restricted to the craniocervical junction, 14 individuals underwent Oc–C2 fusion and 99 underwent surgery exclusively at the C1–2 level. After a mean follow-up period of 9.4 years (range 4.9–14.7 years), 46 patients were available for clinical and radiographic examination, including CT imaging.

Results. None of the 46 patients needed additional surgery to extend the fusion to the occiput. Despite marked deterioration in the subaxial cervical spine, in general there were little or no changes in the atlantooccipital region. All but one patient presented with bony fusion of the fixed C1–2 level at follow-up.

Conclusions. The results of this investigation suggest that if the Oc–C1 joint is free of osseous destructions on conventional radiographs and free of abnormalities on MRI scans at the time of surgery (for transarticular fixation and fusion of C1–2), there is a very low risk for relevant destruction in the following 5–14 years. Thus, no prophylactic oligosegmental approach, but rather a segment-sparing monosegmental approach, is preferred, even in patients with high inflammatory levels.

A systematic review of occipital cervical fusion: techniques and outcomes

J Neurosurg Spine 13:5–16, 2010. DOI: 10.3171/2010.3.SPINE08143

Numerous techniques have been historically used for occipitocervical fusion with varied results. The purpose of this study was to examine outcomes of various surgical techniques used in patients with various disease states to elucidate the most efficacious method of stabilization of the occipitocervical junction.

Methods. A literature search of peer-reviewed articles was performed using PubMed and CINAHL/Ovid. The key words “occipitocervical fusion,” “occipitocervical fixation,” “cervical instrumentation,” and “occipitocervical instrumentation” were used to search for relevant articles. Thirty-four studies were identified that met the search criteria. Within these studies, 799 adult patients who underwent posterior occipitocervical fusion were analyzed for radiographic and clinical outcomes including fusion rate, time to fusion, neurological outcomes, and the rate of adverse events.

Results. No articles stronger than Class IV were identified in the literature. Among the patients identified within the cited articles, the use of posterior screw/rod instrumentation constructs were associated with a lower rate of postoperative adverse events (33.33%) (p < 0.0001), lower rates of instrumentation failure (7.89%) (p < 0.0001), and improved neurological outcomes (81.58%) (p < 0.0001) when compared with posterior wiring/rod, screw/plate, and onlay in situ bone grafting techniques. The surgical technique associated with the highest fusion rate was posterior wiring and rods (95.9%) (p = 0.0484), which also demonstrated the shortest fusion time (p < 0.0064). Screw/rod techniques also had a high fusion rate, fusing in 93.02% of cases. When comparing outcomes of surgical techniques depending on the disease status, inflammatory diseases had the lowest rate of instrumentation failure (0%) and the highest rate of neurological improvement (90.91%) following the use of screw/rod techniques. Occipitocervical fusion performed for the treatment of tumors by using screw/rod techniques had the lowest fusion rate (57.14%) (p = 0.0089). Traumatic causes of occipitocervical instability had the highest percentage of pain improvement with the use of screw/plates (100% improvement) (p < 0.0001).

Conclusions. Based on the existing literature, techniques that use screw/rod constructs in occipitocervical fusion are associated with very favorable outcomes in all categories assessed for all disease processes. For patients requiring occipitocervical arthrodesis for the treatment of inflammatory diseases, screw/rod constructs are associated with the most favorable outcomes, while posterior wiring and onlay in situ bone grafting is associated with the least favorable outcomes. Occipitocervical arthrodesis performed for the diagnosis of tumor is associated with the lowest rate of successful arthrodesis using screw/rod techniques, while posterior wiring and rods have the highest rate of arthrodesis. The nonspecified disease group had the lowest rate of surgical adverse events and the highest rate of neurological improvement.