Individual headless compression screws fixed with three-dimensional image processing technology improves fusion rates of isolated talonavicular arthrodesis

Abstract

BackgroundScrew fixation is a typical technique for isolated talonavicular arthrodesis (TNA), however, no consensus has been reached on how to select most suitable inserted position and direction. The study aimed to present a new fixation technique and to evaluate the clinical outcome of individual headless compression screws (HCSs) applied with three-dimensional (3D) image processing technology to isolated TNA.MethodsFrom 2007 to 2014, 69 patients underwent isolated TNA by using double Acutrak HCSs. The preoperative three-dimensional (3D) insertion model of double HCSs was applied by Mimics, Catia, and SolidWorks reconstruction software. One HCS oriented antegradely from the edge of dorsal navicular tail where intersected interspace between the first and the second cuneiform into the talus body along the talus axis, and the other one paralleled the first screw oriented from the dorsal-medial navicular where intersected at the medial plane of the first cuneiform. The anteroposterior and lateral X-ray examinations certified that the double HCSs were placed along the longitudinal axis of the talus. Postoperative assessment included the American Orthopaedic Foot & Ankle Society hindfoot (AOFAS), the visual analogue scale (VAS) score, satisfaction score, imaging assessments, and complications.ResultsAt the mean 44-months follow-up, all patients exhibited good articular congruity and solid bone fusion at an average of 11.26 ± 0.85 weeks (range, 10 ~ 13 weeks) without screw loosening, shifting, or breakage. The overall fusion rates were 100%. The average AOFAS score increased from 46.62 ± 4.6 (range, 37 ~ 56) preoperatively to 74.77 ± 5.4 (range, 64–88) at the final follow-up (95% CI: −30.86 ~ −27.34; p < 0.001). The mean VAS score decreased from 7.01 ± 1.2 (range, 4 ~ 9) to 1.93 ± 1.3 (range, 0 ~ 4) (95% CI: 4.69 ~ 5.48; p < 0.001). One cases (1.45%) and three cases (4.35%) experienced wound infection and adjacent arthritis respectively. The postoperative satisfaction score including pain relief, activities of daily living, and return to recreational activities were good to excellent in 62 (89.9%) cases.ConclusionsIndividual 3D reconstruction of HCSs insertion model can be designed with three-dimensional image processing technology in TNA. The technology is safe, effective, and reliable to isolated TNA method with high bone fusion rates, low incidences of complications.

Structures at Risk During Percutaneous Screw Fixation for Talonavicular Fusion

“…9,13 In clinical practice, it appears that fusion method is largely driven by the surgeon's preference, with the cannulated screw fixation often being the method of choice for TN fixation. 1,3,22 When screws are inserted percutaneously for TN fusion, there is a risk of iatrogenic injury to the local neurovascular and soft tissue structures. Our cadaveric study aimed to document the safety of percutaneous screw insertion for TN fusion, using 10 thawed fresh-frozen leg specimens that underwent postmortem TN arthrodesis with careful dissection to observe tissue damage following hardware placement.…”

“…9,13 In clinical practice, it appears that fusion method is largely driven by the surgeon’s preference, with the cannulated screw fixation often being the method of choice for TN fixation. 1,3,22…”

“…To achieve optimal fusion, variations of the procedure, with combinations of plates, screws, and staples, have been introduced and have remained a topic of contention. 2,4,13,16,22 In practice, TN fusions are carried out widely based on the surgeon's preference, with one of the most common variations involving the insertion of 2 to 3 screws dorsomedially and dorsolaterally in order to attempt to achieve even compression force. 2,15,16,18,22 The placement of these screws is complicated by the presence of the cuneiforms distal to the navicular bone, which results in poor eccentric compression in respect to the center of the TN joint, and likely contributes to the high incidence of nonunion following a TN fusion surgery.…”

“…2,4,13,16,22 In practice, TN fusions are carried out widely based on the surgeon's preference, with one of the most common variations involving the insertion of 2 to 3 screws dorsomedially and dorsolaterally in order to attempt to achieve even compression force. 2,15,16,18,22 The placement of these screws is complicated by the presence of the cuneiforms distal to the navicular bone, which results in poor eccentric compression in respect to the center of the TN joint, and likely contributes to the high incidence of nonunion following a TN fusion surgery. 9 The highest rate of complication from procedures similar to dorsolateral screw placement (eg, ankle arthroscopy) is that of neurovascular injury, most commonly involving the branches of superficial peroneal nerve, the deep peroneal nerve, and the dorsalis pedis vessel.…”

“…1,3-4,10,15,17,21 The difficulty of achieving TN fusion is currently attributed to the loosening of hardware caused by (1) joint instability when placed under torsional and shear forces or (2) poor vascularization of the bones. 4,13,22…”