Novel mallet/holder manipulation technique for the reduction of anterior slippage in spondylolisthesis: A technical note

Spondylolisthesis and spondylolysis are common causes of chronic low back pain. When conservative treatments fail, lumbar spinal fusion is often the recommended surgical option. This article presents a novel approach to spinal fusion for vertebral misalignment in spondylolisthesis, utilizing mallet manipulation after implant anchoring to correct vertebral slippage during anterior lumbar interbody fusion (ALIF). We describe two male patients, aged 55 and 61, both with severe back pain caused by grade II spondylolisthesis at L5-S1. The second patient also had grade I spondylolisthesis at L4-L5. Failing conservative treatment, both patients required surgical intervention. The patients underwent a two-level ALIF at L4-L5 and L5-S1. For segments with anterior slippage of the vertebral body, the technique involved placing two screws into the upper vertebral body to partially secure the implant position. With the holder attached to the implant and anchored into the upper vertebral body, the segment was advanced by tapping the holder with a mallet until satisfactory alignment was achieved. An awl was then advanced into the vertebral body below, followed by placement of a fixation screw. Fusion was finalized using posterior pedicle screw fixation with O-arm navigation in a minimally invasive percutaneous fashion. Both patients did well post-operatively. At an 8-week post-op exam, imaging showed a healing 2-level fusion with complete correction of their anterior slippage. The patients also reported no back pain. This article demonstrates the feasibility of a novel mallet/holder manipulation technique during an ALIF, aimed at reducing anterior slippage in patients with spondylolisthesis.