Object Surgical treatment of atlantoaxial instability has evolved to include various posterior wiring techniques including Brooks, Gallie, and Sonntag fusions in which success rates range from 60 to 100%. The Magerl–Seemans technique in which C1–2 transarticular screws are placed results in fusion rates between 87 and 100%. This procedure is technically demanding and requires precise knowledge of the course of the vertebral arteries (VAs). The authors introduce a new C1–2 fixation procedure in which C-1 lateral mass and C-2 pedicle screws are placed that may have advantages over C1–2 transarticular screw constructs. Methods A standard posterior C1–2 exposure is obtained. Polyaxial C-2 pedicle screws and C-1 lateral mass screws are placed bilaterally. Rods are connected to the screws and secured using locking nuts. A cross-link is then placed. Fusion can be performed at the atlantoaxial joint by elevating the C-2 nerve root. The technique for this procedure has been used in four cases of atlantoaxial instability at the author's institution. There have been no C-2 nerve root– or VA-related injuries. No cases of construct failure have been observed in the short-term follow up period. Conclusions Atlantoaxial lateral mass and axial pedicle screw fixation offers an alternative means of achieving atlantoaxial fusion. The technique is less demanding than that required for transarticular screw placement and may avoid the potential complication of VA injury. The cross-linked construct is theoretically stable in flexion, extension, and rotation. Laminectomy or fracture of the posterior elements does not preclude use of this fixation procedure.

Surveys of the phlebotomine fauna in a focus of zoonotic cutaneous leishmaniasis (ZCL) in the Al-Hassa oasis, Eastern Province, Saudi Arabia, revealed only one species of Phlebotomus (P. papatasi) and three of Sergentomyia (S. antennata, S. clydei and S. fallax). 11 specimens of P. papatasi from six sites in the oasis were found with promastigotes in the midgut. An isolate from one of the sandflies was typed by the examination of isoenzymes and identified as Leishmania major, zymodeme LON-4 (= Montpellier zymodeme 26), the principal zymodeme of L. major isolated from patients with ZCL in the oasis. Three isolates from leishmanial lesions at sites of the bites of wild caught specimens of P. papatasi were also identified as the same zymodeme of L. major as the isolate from the sandfly. The findings show that P. papatasi is the vector of ZCL in the Al-Hassa oasis and probably in other ecologically similar foci in the Kingdom.

No abstract

No abstract