Introduction: Anterior cranial fossa defects (ACF) still remains a reconstructive challenge to neurosurgeons due to difficult location, inaccessibility and unfavorable vascular anatomy. Usual reconstructive methods reported complications like recurrent cerebrospinal fluid leak due to bone resorption and tissue breakdown. This is mainly due to the avascularity of the bone graft and inability to provide bony structural support for the skull base. An ideal reconstructive modality should provide a rigid bony support to prevent brain herniation as well as ensure a water tight barrier between sinonasal tract and intracranial compartment

Methodology: So we thought of a novel technique of taking the outer table of the primary craniotomy flap with its intact myofascial pedicle and moulded it with multiple osteotomies (Moulded Osteomyofascial Pedicled Split craniotomy flap(MOPS)) in order to fit into uneven anterior cranial fossa defects. Advantages of our flap include:
1) It is a pedicled vascularised bone flap. 2) It is taken from primary craniotomy flap hence no separate craniotomy is required. 3) The inner table is intact and leaves no secondary calvarial bone defect on the donor site.4) Osteoplastic flap is moulded to fit into the defect thus provides good contour.

Result: MOPS flap was used in 5 patients with ACF defects due to varied etiologies like encephalocele defect, frontal mucocele, skull base meningioma and complex naso ethmoid fracture Age of the patients included in the study varied from 21-60 yrs. M:F ratio was 4:1.ACF defects were reconstructed using MOPS flap in all cases. There were no postoperative complications and 1 month post operative CT scan showed no evidence of bone resorption and acceptable cosmesis.

Conclusion: MOPS craniotomy flap provides a novel, easily mastered and cost effective technique with minimal complication in reconstruction of complex anterior cranial fossa defects with acceptable aesthetic and functional outcome.