How many screws are necessary for subtalar fusion? A retrospective study. Issue 6 (August 2020)

• Record Type: Journal Article
• Authors: Wirth, Stephan H.; Viehöfer, Arnd; Fritz, Yannick; Zimmermann, Stefan M.; Rigling, Dominic; Urbanschitz, Lukas
• Is Part Of: Foot and ankle surgery. Volume 26:Issue 6(2020)
• Page Start: 699
• Page End: 702
• Publication Date: 2020-08
• Subjects: Subtalar -- Arthrodesis -- Screws -- Fusion -- Revision; Foot -- Surgery -- Periodicals; Ankle -- Surgery -- Periodicals; Ankle -- surgery -- Periodicals; Foot -- surgery -- Periodicals; Ankle -- Surgery; Foot -- Surgery; Periodicals; Electronic journals; 617.58
• DOI: 10.1016/j.fas.2019.08.017
• Languages: English
• ISSNs: 1268-7731

Abstract

Highlights: For subtalar arthrodesis, 3-screw-fixation has lower revision arthrodesis and non-union rate compared to 2-screw-fixation. Prior ankle fusion, BMI ≥30 kg/m 2 and diabetes mellitus are relevant risk factors for revision arthrodesis. This study confirms the clinical relevance of previous in vitro findings for subtalar arthrodesis. Abstract: Background: Biomechanical studies have shown a higher compressive force and higher torsional stiffness for fixation with three screws compared to two screws. However, clinical data to compare these fixation techniques is still lacking. Methods: A retrospective analysis of 113 patients was performed, who underwent isolated subtalar fusion between January 2006 and April 2018. Results: Revision arthrodesis was required in 8% (n = 6/36) for 3-screw-fixation and 38% (n = 35/77) for 2-screw-fixation. For 3-screw-fixation, non-union, was observed in 14% (n = 5/36) compared to 35% (n = 27/77) in 2-screw fixation. Non-union (p = .025) and revision arthrodesis (p = .034) were significantly more frequent in patients with 2 screws. A body mass index ≥30 kg/m 2 (p = .04, OR = 2.6, 95%CI:1.1–6.3), prior ankle-fusion (p = .017, OR = 4.4, 95%CI:1.3–14.5) and diabetes mellitus (p = .04, OR = 4.9, 95%CI:1.1–17.8) were associated with a higher rate of revision arthrodesis. Conclusions: Our findings suggest that successful subtalar fusion is more reliably achieved with use of three screws. However, future prospective studies will be necessary to further specify this recommendation.