Dynamic syndesmotic stabilisation and reinforcement of the antero-inferior tibiofibular ligament with internal brace

PURPOSE

Syndesmotic injuries are associated with long recovery times and high morbidity. Systematic reviews show a trend toward better outcomes of suture buttons compared to screw fixation. The anteroinferior tibiofibular ligament (AITFL) confers the most significant component of translational and rotatory stability. Techniques have developed which reinforce the AITFL. This study aimed to assess results of syndesmotic stabilisation with dynamic stabilisation and reinforcement of the AITFL, with an early mobilisation program.

MATERIALS AND METHODS

Retrospective case series of 30 patients (mean age 31 years). Syndesmotic instability was confirmed with clinical examination, MRI and weightbearing-CT. Dynamic syndesmotic stabilisation with a single suture button was performed followed by the placement of an Internal Brace over the AITFL. A standardised postoperative rehabilitation protocol was established. Foot and Ankle Ability Measure (FAAM) scores were collected postoperatively.

RESULTS

The average follow-up was 13 months. The total FAAM score for ADL was 95 ± 4.9 % (range, 83 - 100 %) and for sport activities 87 ± 13.6 % (range, 50 - 100 %). The rating of mean postoperative function for ADL was 94 ± 5.5 % (range, 80 - 100 %) and 90 ± 13 % (range, 35 - 100 %) for sportv. The difference between acute and chronic injuries was statistically higher (p < 0.05) for daily activities and sport, but the rating of current level of sport activites as well as for daily activites did not show a significant difference (p = 0.9296 and p = 0.1615, respectively). Twenty-seven patients (90 %) rated their overall current level of function as normal or nearly normal.

CONCLUSION

This technique aims to directly stabilise the AITFL and the interosseous components of the syndesmosis, and allow early mobilisation and return to sport at 10 weeks. Early results show the procedure is safe, with comparable results to the literature. Acute injuries showed better results of the FAAM score than chronic injuries.

The anatomy of the anterior inferior tibiofibular ligament and its relationship with the Wagstaffe fracture

BACKGROUND

Our aim in this study was to identify the fibular footprint of the Anterior Inferior Tibiofibular Ligament (AITFL) and its relation to Wagstaffe fracture fragment size.

METHODS

We examined 25 cadaveric lower limbs which were carefully dissected to identify the lateral ankle ligaments. The AITFL anatomy was compared to 40 Wagstaffe fractures identified from our ankle fracture database.

RESULTS

The AITFL origin was from the anterior fibular tubercle with an average length of 21.61 mm (95% CI 20.22, 22.99). The average distance of the distal aspect of the AITFL footprint to the distal fibula margin was 11.60 mm (95% CI 10.49, 12.71). In the ankle fractures analyzed, the average length of the Wagstaffe fragment was 17.88 mm (95% CI 16.21, 19.54). The average distance from the distal tip of the fibula to the Wagstaffe fracture fragment was 21.40 mm (95% CI 19.78, 23.01). In total there were 22 syndesmosis injuries. There was no statistical difference in Wagstaffe fragment size between stable and unstable groups.

CONCLUSION

The AITFL fibular origin was both larger and more distal than the Wagstaffe fracture fragments seen in our institution. Therefore, this suggests that a ligamentous failure will also have to occur to result in syndesmotic instability. The size of fracture fragment also did not confer to syndesmotic instability on testing. Level of Evidence - 3.

Scanned versus Fused-Reconstructed Oblique MR-Images for Assessment of the Tibiofibular Syndesmosis-Diagnostic PerFormance and Reader Agreement

To evaluate the diagnostic performance and reader agreement of a novel MRI image fusion method enabling the reconstruction of oblique images for the assessment of the tibiofibular syndesmosis. We evaluated 40 magnetic resonance imaging examinations of patients with ankle sprains (16 with ruptures and 24 without) for the presence of anteroinferior tibiofibular ligament rupture. For all patients, we performed a fusion of standard two-dimensional transversal and coronal 3 mm PDw TSE images into an oblique-fusion reconstruction (OFR) and compared these against conventionally scanned oblique sequence for the evaluation of the tibiofibular syndesmosis. To evaluate diagnostic performance, two expert readers independently read the OFR images twice. We analyzed sensitivity, specificity, negative and positive predictive values, accuracy, and agreement. Reader 1 misinterpreted one OFR as a false negative, demonstrating a sensitivity of 0.94 and specificity of 1.00, reader 2 demonstrated perfect accuracy. Intrareader agreement was almost perfect for reader 1 (α = 0.95) and was perfect for reader 2 (α = 1.00). Additionally, interreader agreement between all fusion sequence reads was almost perfect (α = 0.97). The proposed OFR enables reliable detection of anteroinferior tibiofibular ligament rupture with excellent inter- and intrareader agreement, making conventional scanning of oblique images redundant and supplies a method to retroactively create oblique images, e.g., from external examinations.

Diagnostic capability of dynamic ultrasound evaluation of supination-external rotation ankle injuries: a cadaveric study

BACKGROUND

Ankle syndesmosis injuries are common and range in severity from subclinical to grossly unstable. Definitive diagnosis of these injuries can be made with plain film radiographs, but are often missed when severity or image quality is low. Computed tomography (CT) and magnetic resonance imaging (MRI) can provide definitive diagnosis, but are costly and introduce the patient to radiation when CT is used. Ultrasonography may circumvent many of these disadvantages by being inexpensive, efficient, and able to detect injuries without radiation exposure. The purpose of this study was to evaluate the ability of ultrasonography to detect early stage supination-external rotation (SER) ankle syndesmosis injuries with a dynamic external rotational stress test.

METHODS

Nine, all male, fresh frozen specimens were secured to an ankle rig and stress tested to 10 Nm of external rotational torque with ultrasonography at the tibiofibular clear space. The ankles were subjected to syndesmosis ligament sectioning and repeat stress measurements of the tibiofibular clear space at peak torque. Stress tests and measurements were repeated three times and averaged and analyzed using a repeated one-way analysis of variance (ANOVA). There were six ankle injury states examined including: Intact State, 75% of AITFL Cut, 100% of AITFL Cut, Fibula FX - Cut 8 cm proximal, 75% PITFL Cut, and 100% PITFL Cut.

RESULTS

Dynamic external rotation stress evaluation using ultrasonography was able to detect a significant difference between the uninjured ankle with a tibiofibular clear space of 4.5 mm and the stage 1 complete injured ankle with a clear space of 6.0 mm (P < .02). Additionally, this method was able to detect significant differences between the uninjured ankle and the stage 2-4 injury states.

CONCLUSION

Dynamic external rotational stress evaluation using ultrasonography was able to detect stage 1 Lauge-Hansen SER injuries with statistical significance and corroborates criteria for diagnosing a syndesmosis injury at ≥6.0 mm of tibiofibular clear space widening.

Ligamentous advancement for the treatment of subacute syndesmotic injuries. Report of a new technique in 5 cases

BACKGROUND

Integrity and optimum functioning of the syndesmotic ligament complex is of paramount importance for stability of the ankle joint during various ankle movements. Persistent widening and chronic isolated instability of the distal tibio-fibular syndesmosis leads to poor functional outcome and the development of osteoarthritis. In subacute total ruptures the focus of treatment is to restore the normal anatomy by repair of the ruptured ligament and to protect the reconstruction for a period of time. Various techniques have been previously reported with good results but associated with donor site morbidity and multiple incisions.

METHOD

Ligamentous advancement allows repair of the syndesmosis when the AITFL is dysfunctional but intact. The lax AITFL was mobilised with periosteum from the tibia leaving the fibular side intact. The Syndesmosis was cleared, reduced with a clamp, and held with two syndesmotic screws inserted transversely between the distal fibular and tibial shafts. The tibial surface was roughened to receive the new attachment of AITFL. The sleeve of tissue was then secured to the roughened tibial surface under tension using suture anchors with the ankle in neutral position. The repair was protected with a two hole plate and screws.

RESULTS

The functional outcome scores showed excellent outcome at the end of 6 months.

CONCLUSION

Ligamentous advancement technique obviates the need of any bony procedure and does not involve the use of any material which will lead to any sort of foreign body reaction or donor site morbidity while providing anatomical reconstruction of the syndesmosis with excellent functional outcome.