The role of Poller screws in intramedullary nailing for lower limb extra-isthmic fractures.

INTRODUCTION

Intramedullary nailing is the preferred treatment for lower limb long bone fractures, but stability is reduced in extra-isthmic fractures due to nail-metaphysis mismatch. Poller screws may help, but their use is controversial. This study evaluates whether Poller screws are associated with improved prognosis in intramedullary nailing for lower limb extra-isthmic fractures and explores their mechanical mechanisms.

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were searched up to December 2025 using keywords like 'Fracture,' 'Intramedullary nail,' 'Poller screw,' and 'Blocking screw.' Studies were screened, and data were collected for meta-analysis. A 3D tibial model was created, and finite element analysis assessed Poller screws' effect on distal tibial fractures under axial load.

RESULTS

Out of 1134 studies, 5 trials with 413 participants were included. The Poller screw group showed increased union rates (OR = 2.48; 95% CI, 1.13-5.46; p = 0.020). Surgery duration increased, but secondary surgical procedures decreased. No differences were found in malalignment, time to union, or infection. Poller screws reduced fracture site displacement by 54.88%.

CONCLUSION

The use of Poller screws in intramedullary nailing for lower limb extra-isthmic fractures is associated with higher union rates without affecting alignment or healing time. While surgery duration increases, infection remains unchanged, and secondary surgery decreases. The improved healing outcomes may contribute to Poller screws enhancing construct stiffness and reducing micro-motion.