Dual Window Approach With Two-Side Screw Fixation for Isolated Talonavicular Arthrodesis

Hindfoot Arthrodeses and the Order of Joint Fixation Influence Tibiotalar Kinematics During Simulated Stance

BACKGROUND

Although hindfoot arthrodeses relieve pain and correct deformity, they have been associated with progressive tibiotalar degeneration. The objective was to quantify changes in tibiotalar kinematics after hindfoot arthrodeses, both isolated subtalar and talonavicular, as well as double arthrodesis, and to determine if the order of joint fixation affects tibiotalar kinematics.

METHODS

Hindfoot arthrodeses were performed in 14 cadaveric mid-tibia specimens. Specimens randomly received isolated fixation of the subtalar or talonavicular joint first, followed by fixation of the remaining joint for the double arthrodesis. A 6-degree-of-freedom robot sequentially simulated the stance phase of level walking for intact, isolated, and double arthrodesis conditions. Tibiotalar kinematic changes were compared for the intact and arthrodesis conditions. A subsequent analysis assessed the effect of the joint fixation order on tibiotalar kinematics.

RESULTS

Isolated and double hindfoot arthrodeses increased tibiotalar plantarflexion, inversion, and internal rotation during late stance. Tibiotalar kinematics changes occurring after isolated arthrodesis remained consistent after the double arthrodesis for both the subtalar- and talonavicular-first conditions. The order of joint fixation influenced tibiotalar kinematics through some portions of stance, where the talonavicular-first double arthrodesis increased tibiotalar plantarflexion, eversion, and internal rotation compared to the subtalar-first double.

CONCLUSION

Tibiotalar kinematics were modestly altered for all conditions, both isolated and double hindfoot arthrodeses. Changes in tibiotalar kinematics were consistent from the isolated to the double arthrodesis conditions and varied depending on which isolated hindfoot arthrodesis was performed first. Further research is needed to assess the clinical implications of the observed changes in tibiotalar kinematics, particularly as it pertains to the development of adjacent joint arthritis.

CLINICAL RELEVANCE

These findings may correlate with clinical research that has cited hindfoot arthrodesis as a risk factor for adjacent tibiotalar arthritis. Once either the subtalar or talonavicular joint is fused, avoiding the arthrodesis of the second joint may not necessarily protect the tibiotalar joint.

Which surgical approach is optimal for joint preparation in talonavicular fusion - A cadaver study

BACKGROUND

Fusion of the talonavicular joint has proven challenging in literature. The optimal surgical approach for talonavicular arthrodesis is still uncertain. This study compares the amount of physical joint preparation between dorsal and medial approaches to the talonavicular joint.

METHODS

Twenty fresh frozen cadaver specimens were randomly assigned to receive either a dorsal or medial operative approach to the talonavicular joint. The joint surface was prepared, and the joint was disarticulated. Image analysis, using ImageJ, was performed by two blinded reviewers to assess the joint surface preparation and this was compared by surgical approach.

RESULTS

The dorsal approach had a higher median percentage of talar and total talonavicular joint surface area prepared (75% vs. 59% (p = .007) and 82% vs. 70% (p = .005)). Irrespective of approach, the talus was significantly more difficult to prepare than the navicular (62% vs 88% (p = .001)).

CONCLUSION

The dorsal approach provides superior talonavicular joint preparation. The lateral ¼th of the talar head was the most difficult surface to prepare, and surgeons performing double or triple arthrodesis may prepare the lateral talar head from the lateral approach.

LEVEL OF EVIDENCE

Level V.

Structures at Risk During Percutaneous Screw Fixation for Talonavicular Fusion

BACKGROUND:

Talonavicular (TN) fusion using screws dorsomedially and dorsolaterally can cause neurovascular injury. The purpose of our cadaveric study was to evaluate the safety of percutaneous screw insertion in relation to dorsal neurovascular structures.

METHODS:

Ten fresh-frozen cadaver legs were used for this study. Percutaneous cannulated screws were inserted to perform isolated TN arthrodesis. The screws were inserted at 3 consistent sites: a "medial screw" at the dorsomedial navicular where it intersected at the medial plane of the first cuneiform, a "central screw" at the edge of the dorsal navicular between the medial and intermediate cuneiforms, and a "lateral screw" at the edge of the dorsal navicular between the intermediate and lateral cuneiforms. Superficial and deep dissections were carried out to identify any injured nerves, arteries, and/or tendons.

RESULTS:

The medial screw injured the anterior tibialis tendon in 2 cases (20%), the central screw injured the extensor hallucis longus tendon in 3 cases (30%), and the lateral screw injured the anterior branch of the superior peroneal nerve (SPN), the lateral branch of the SPN, and the medial branch of the distal peroneal nerve (DPN) once each in a total of 3 cases (30%). Despite no direct injury, the central screw indicated a potential risk of neurovascular injury: closest distance to the anterior SPN was 2 mm and to the medial DPN 2 mm.

CONCLUSION:

Although neurovascular injury risk exists for all of these screw placements, TN fusion with a central screw introduced a potentially decreased risk of neurovascular injury at the expense of increased risk of tendon injury compared to the lateral screw.

CLINICAL RELEVANCE:

Based on these results, we recommend a careful dissection be performed prior to percutaneous screw insertion.

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

BACKGROUND

Screw 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.

METHODS

From 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.

RESULTS

At 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.

CONCLUSIONS

Individual 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.