Efficiency of locking-plate fixation in isolated talonavicular fusion

What is the best fixation technique for isolated talonavicular arthrodesis? - A systematic review

Talonavicular arthrodesis is associated with a rate of non-union that ranges from 3 % to 37 %. Various fixation devices have been reported for talonavicular arthrodesis including screws, staples, plates, K-wires and intraosseous fix systems, however there is no definitive gold standard. This systematic review aims to compare clinical outcomes between different fixation devices for talonavicular arthrodesis.

METHODS

MEDLINE, EMBASE, CENTRAL and Google Scholar were reviewed for studies reporting on outcomes of different fixation techniques for talonavicular arthrodesis indicated for osteoarthritis, inflammatory and post-traumatic arthritis from 1946 to 2021. The primary outcome measure was union rate. Secondary outcome measures included functional improvement, cost, quality of life and patient satisfaction.

RESULTS

9 articles involving 141 cases of talonavicular arthrodesis were identified. Fusion rates were as follows: screw fixation (n = 75): 87.5 % to 100 %, staple fixation (n = 13): 100 %, intraosseous fix system (n = 16): 100 %, and K-wire fixation (n = 2): 100 %. One study utilised a dorsal locking plate with two supplemented compression screws (n = 9, fusion rate= 100 %) and two studies used a combination of screws with staples (n = 26, fusion rate= 96 %). 7 of 9 studies measured functional outcomes and pain relief with improvement demonstrated in all fixation techniques. Quality of life, satisfaction and cost were inadequately reported amongst the included studies. All studies were rated as serious risk of bias.

CONCLUSION

This systematic review consolidates the evidence for outcomes of different fixation techniques for TN arthrodesis, however a definitive judgement regarding the best fixation technique is unobtainable from current clinical evidence, due to lack of high-quality studies. With review of biomechanical studies and the limited clinical data, fixation with plate plus screw is most promising and would warrant further comparative study.

LEVEL OF EVIDENCE

IV.

Talo-navicular and calcaneo-cuboid fusion with PEEK H-pode™ vs. Titanium Maxlock™ locking plates: Comparison of functional and radiographic outcomes

BACKGROUND

Locking plates are increasingly used to achieve hindfoot fusion. The objective of this study was to compare hindfoot fusion outcomes with the PEEK H-pode™ (Biotech™) locking plate and the titanium Maxlock™ (Tornier-Wright™) locking plate.

HYPOTHESIS

A polyetheretherketone (PEEK) H-pode™ locking plate provides similar fusion rates to a titanium Maxlock™ locking plate for talo-navicular and calcaneo-cuboid arthrodesis.

METHODS

We conducted a retrospective comparative study in 39 patients (including 21 [54%] with pes planovalgus and 11 [28%] with neurological equinovarus deformities) who underwent talo-navicular and/or calcaneo-cuboid fusion, usually combined with subtalar fusion. The first 17 patients (January 2014-February 2016) were managed with Maxlock™ locking plates and the next 22 patients (March 2016-August 2018) with H-pode™ locking plates. These two cohorts of consecutive patients were comparable regarding age, sex distribution, body mass index, and comorbidities. At last follow-up more than 1year after surgery, we compared functional scores, pain intensity, and fusion assessed by radiographs and computed tomography (CT) (threshold set at 33%).

RESULTS

Mean follow-up was 42months (range: 34-63months) in the Maxlock™ group and 25months (range: 12-36months) in the H-pode™ group. At last follow-up, the two groups were not significantly different for the mean values of the American Orthopedic Foot & Ankle Society score, European Foot & Ankle Society score, and visual analogue scale pain score. Neither were the two groups significantly different for talo-navicular and calcaneo-cuboid fusion by CT. In the Maxlock™ group, we found non-significant trends towards a higher proportion of patients with talo-navicular nonunion (18% vs. 5% in the H-pode™ group) and weaker talo-navicular fusion in patients with pes planovalgus (60.8% vs. 82.0%, respectively). Radiographic results overestimated the fusion rates.

DISCUSSION

Talo-navicular and calcaneo-cuboid fusion was not significantly different with H-pode™ and Maxlock™ locking plates. CT was more accurate than standard radiography to assess fusion. These results underline the usefulness of PEEK locking plates for talo-navicular and calcaneo-cuboid fusion; moreover, the radiolucency of PEEK facilitates the interpretation of radiographs.

LEVEL OF EVIDENCE

IV.

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.

Effect of Bone Quality and Leg Depth on the Biomechanical Performance of a Nitinol Staple

The use of Nitinol compression staples has increased in foot and ankle procedures due to their ease of delivery and ability to offer sustained, dynamic compression. Prior biomechanical studies have predominantly examined mechanical performance in healthy bone models without investigating the effect of unicortical versus bicortical fixation. The purpose of this study was to examine the effect of bone quality and staple leg depth on the biomechanical performance of Nitinol staples in a bicortical bone model. Two-legged Nitinol staples were implanted in bicortical sawbone of 2 densities. Two different leg depths were tested to simulate unicortical versus bicortical fixation. Interfacial compressive forces, interfacial compression area, torsional strength, and shear strength were measured for each group. The effect of leg depth was minimal compared to the effect of sawbone density on the mechanical performance of Nitinol staples. Interfacial compressive force and interfacial compression areas were greater in the low density bone model, while torsional strength and shear strength were greater in the normal density bone model. Nitinol staple's mechanical performance is highly dependent upon bone quality and less dependent on whether staple legs terminate in cancellous versus cortical bone. Low density bone allows for a higher compressive interfacial area to be imparted by the staple. Staples in normal density bone are able to resist torsion and shear deformation more readily than staples in low density bone. Bone density may have a greater effect on the Nitinol staple's stability and compressive capability in vivo as compared to unicortical versus bicortical leg fixation.

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.

[Effectiveness of talonavicular arthrodesis for Müller-Weiss disease]

Objective

To evaluate the short-term effectiveness of talonavicular arthrodesis for Müller-Weiss disease.

Methods

Between May 2013 and February 2015, 13 patients with Müller-Weiss disease were treated with talonavicular arthrodesis. There were 11 females and 2 males with an average age of 59 years (range, 42-67 years). The disease duration was 8-20 years (mean, 13 years). According to Maceira stage, there were 7 cases of stage Ⅲ, 6 cases of stage Ⅳ. The foot longitudinal arch height measured on weight-bearing X-ray films was (43.1±1.8) mm; the Meary angle and talocalcaneal angle measured on lateral X-ray films were (-2.8±2.3)° and (5.8±2.4)°, respectively; the calcaneal valgus angle measured on Saltzman position X-ray films was (-2.0±0.7)°. The American Orthopaedic Foot and Ankle Society (AOFAS) score was 43.5±12.4, and visual analogue scale (VAS) score was 7.3±1.5.

Results

All the patients were followed up 14-39 months (mean, 20 months). The symptoms of foot pain and intermittent claudication disappeared in all patients. All cases achieved bony union, the fusion time was 12-16 weeks (mean, 13 weeks). There was no complications such as wound infection, skin necrosis, or internal fixator broken. At last follow-up, the foot longitudinal arch height, Meary angle, talocalcaneal angle, and calcaneal valgus angle were (52.5±2.2) mm, (1.3±2.2)°, (16.5±3.7)°, and (0.4±0.7)°, respectively; the AOFAS score and VAS score were 83.8±9.1 and 1.0±0.4, respectively; all were significantly improved when compared with preoperative ones ( P<0.05).

Conclusion

If the subtalar and calcaneocuboid joints are relatively healthy, talonavicular arthrodesis may be a reliable and effective surgical option for Müller-Weiss disease that is resistant to conservative treatment.