[Posterior C1-C2 arthrodesis. Experience in transarticular and interarticular fixation in 36 patients]

The stabilization of C1-C2 segment has evolved with the appearance of several techniques from sublaminar, transarticular or interarticular fixation and over recent years with the introduction of neuronavegation systems. The aim of the study was to review patients treated in our center with transarticular and interarticualr fixation and compare the results obtained with both techniques.

Thirty six patients with C1-C2 instability that required a surgical fixation between 1995-2008 were retrostpectively analized. The causes of instability were principaly traumatic (18 cases) or degeneritive (16) and two cases of neoplasic lesions. In the first period (1995-2001) 20 patients were treated with transarticular fixation (Magerl's technique), and later (2002-2008) with interarticular fixation (Goel-Harms technique) in another 16 patients. Data was obtainned regarding complications, radiological evolution and clinical results (EVA pain score) and functionals (PROLO score) at 3, 6, 12 and >12 months post-op, as well as post-op cervical mobility and signs of bone fusion. A good result was considered if clinical improvement exi ted with decrease in EVA pain score > 5 points and funcional if a PROLO score > 4, regular if EVA decreased but <5 and PROLO <3 , and bad if there was no clinical or functional improvement. The results were statistically compared between both techniques.

Of the 20 patients treated with transarticular fixation, good results were obtained in 17 cases (85%) , regular in 2 (10%), and bad in 1 (5%). Complications included 1 case of vertebral artery lesion and 3 screw misplacements, one case in contact with vertebral artery. Regarding those treated with interarticualr fixation, in 14 (89%), good results were obtained, regular in 2 (12.5%) with 1 case of screw misplacement and another of postsurgical infection. No statistical significant differences were recorded between both techniques, although in those treated with interarticular fixation there was a higher rate of bone fusion and no cases of vertebral arterial lesions were recorded.

Transarticular and interarticular C1- C2 fixation is safe and provides a high rate of good results with few complications. The introduction of neuronavigation systems can increase the efficacy and safety of these techniques.