Current Insights On Internal Fixation Of Subtalar Fusions
- Volume 25 - Issue 6 - June 2012
- 9414 reads
- 0 comments
In contrast to those findings, tapping reduced pullout strength by 8 percent in compasrison to non-tapped guide holes.18 Pullout forces utilizing the anterior to posterior screw orientation had a larger mean failure load in comparison to the pullout forces using the posterior to anterior approach. Specifically, mean failure load for the anterior to posterior approach was 1782 N whereas the mean failure load for the posterior to anterior screw orientation was 1245 N.12 Chapman and colleagues proved that the best screw placement is at the entrance point where the cortex is the thickest.18 Thick cortical bone has been critical in assisting with stabilization of internal fixation. Indeed, the thick cortical bone of the talus is another advantage for the anterior to posterior approach.
One can inadequately assess deviations medially or laterally from the central aspect of the calcaneus when utilizing only the intraoperative lateral radiographic view. Accordingly, the calcaneal axial view is required to confirm appropriate placement of the guide wire into the central aspect of the calcaneus prior to screw placement. This tip is critically important in the posterior to anterior screw placement as the landing zone is small. Though our cadaver study demonstrated the “top down” screw to be reproducible and generally central into the calcaneus, we still recommend the additional imaging view.
Dr. Scott is a Fellow of the Orthopedic Foot and Ankle Center in Westerville, Ohio. He is an Associate of the American College of Foot and Ankle Surgeons.
Dr. Hyer is the Fellowship Director of Orthopedic Foot and Ankle Center in Westerville, Ohio. He is a Fellow of the American College of Foot and Ankle Surgeons.
1. Gosch C, Verrette R, Lindsey D, Beaupre G, Lehnert B. Comparison of initial compression for across the subtalar joint by two different screw fixation techniques. J Foot and Ankle Surg. 2006; 45(3):168-73.
2. Haskell A, Pfeiff C, Mann R. Subtalar joint arthrodesis using a single lag screw. Foot Ankle Int. 2004; 25(11):774-77.
3. Easley ME, Trnka H, Schon LC, Myerson MS. Isolated subtalar arthrodesis. J Bone Joint Surg. 2000;2-A(5):613-24.
4. Potenenza V, Caterini R, Farsetti P, Bisicchia S, Ippolito E. Primary subtalar arthrodesis for the treatment of comminuted intra-articular calcaneal fractures. Injury. 2010;41(7):702-6.
5. Radnay CS, Clare MP, Sanders RW. Subtalar fusion after displaced intra-articular calcaneal fractures: does initial operative treatment matter? J Bone Joint Surg. 2009; 1(91):541-6.
6. Hinterman B, Valderrabano V, Nigg B. Influence of screw type on obtained contact area and contact force in a cadaveric subtalar arthrodesis model. Foot Ankle Int. 2002; 23(11):986-91.
7. Catanzariti AR, Mendicino RW, Saltrick KR, Orsini RC, Dombek MF, Lamm BM. Subtalar arthrodesis. J Am Podiatr Med Assoc. 2005; 95(1):34-4.
8. Cohen BE, Johnson JE. Subtalar arthrodesis for treatment of posterior tibial tendon insufficiency. Foot Ankle Clin. 2001; 6(1):121-8.
9. Sammarco VJ, Magur EG, Sammarco J, Bagwe MR. Arthrodesis of the subtalar and talonavicular joints for correction of symptomatic hindfoot malalignment. Foot Ankle Int. 2006; 27(9):661-66.
10. Mann RA. Arthrodesis of the foot and ankle. In: Mann RA, Coughlin MJ (eds.): Surgery of the foot and ankle, 6th edition, Mosby, St. Louis, 1993, pp. 673-713.
11. Scanlan RL, Burns PR, Crim BE. Technique tip: Subtalar joint fusion using a parallel guide and double screw fixation. J Foot Ankle Surg. 2010; 49(1):305-309.
12. McGlamry MC, Robitaille MF. Analysis of screw pullout strength: A function of screw orientation in subtalar joint arthrodesis. J Foot Ankle Surg. 2004; 43(5):277-284.
13. Gable SJ, Bohay DR, Manoli A. Technique tip: aiming guide for accurate placement of subtalar joint screws. Foot Ankle Int. 1995; 16(4):238-39.