The limitations of fully threaded screws in isolated percutaneous transarticular screw fixation of C1/C2

Abstract

Demographic aging accompanied by increased falls inevitably leads to an increased incidence of atlantoaxial instabilities (AAI). Minimally invasive surgical procedures decrease the perioperative risk and regarding the treatment of AAI, percutaneous transarticular screw fixation of C1/C2 was more frequently considered in the past. This study aims to investigate the outcome of patients treated for AAI by isolated percutaneous transarticular screw fixation of C1/C2 (IPTSFC1/C2) using 3.5 mm fully threaded screws to identify its chances and limitations. In this retrospective study, data from patients who underwent IPTSFC1/C2 were analyzed. 23 patients (17 females and 6 males) with an average age of 73.1 years (y) were included. Mean VAS decreased significantly from preoperative 3.9 ± 1.8 to the last follow-up 2.6 ± 2.5 (p = 0.020) and neurological functions were preserved. In the radiological follow-up, we saw a single malposition of an inserted screw (2.27%) and one single bony fusion (4.54%). However, in 6 of 7 patients (85.71%), there was a loosening of the inserted screws due course. We demonstrated that the use of 3.5 mm fully threaded screws for IPTSFC1/C2 results in low rates of osseous fusions between C1 and C2. Therefore, their use in IPTSFC1/C2 is not suitable, especially for geriatric patients with impaired bone status.

A Comparative Meta-Analysis of Implant-Related Complications and Fusion Rates for the Atlantoaxial Fusion with Transarticular Screws and Screw-Rod Constructs.

“…Unfortunately, Vergara et al did not describe the surgical technique in their article. Furthermore, radiographic evidence of TAF failure revealed the use of fully threaded screws, known risk factors for C1-C2 nonunion [27], likely contributing to the lower fusion rate reported in TAF by Vergara. This study underscores the lack of signi cant differences in surgical duration, intraoperative blood loss, frequency of implant-related complications, and overall outcomes between the two leading C1-C2 fusion techniques. We observe notable advantages with the TAF method, particularly its lower implant costs (requiring only two screws) and its wider applicability for minimally invasive procedures [28][29][30][31].…”

Comparative meta-analysis of implant-associated complications and spinal fusion incidence in Goel-Harms technique and posterior С₁-С₂ transarticular screw fixation per F. Magerl

“…Более того, на одном из рентгеновских снимков, отражающих несостоятельность фиксации при ТАФ, можно увидеть полнорезьбовые винты. Данные импланты являются достоверным фактором риска развития несращения С 1 -С 2 -позвонков [27], что, по-видимому, и обусловливает низкую частоту спондилодеза после ТАФ в работе P. Vergara и соавт.…”