Ankle fracture with syndesmotic injury

Peroneal Tendon Lengthening as an Adjunct Procedure to Aid in the Reduction of the Lateral Malleolus in Diabetic Ankle Fractures: 2 Case Reports

It is well-documented that individuals with longstanding diabetes mellitus are at risk for specific metabolic abnormalities; this includes but is not limited to increased glycation of collagenous soft-tissue structures. It is also apparent that such changes can manifest as thickening and increased stiffness of tendinous structures. What remains unknown are the biomechanical ramifications of these changes and how they should affect the surgical management of lower extremity injuries. Previous research suggests that the Achilles tendon demonstrates increased stiffness in the presence of diabetes. It is therefore reasonable to presume that increased collagen glycation and the resultant tendon stiffness can also lead to decreased extensibility and shortening of the peroneus longus and brevis tendons. The significance of this leads us to the conclusion that glycation of the peroneal tendons can create a deforming force in displaced lateral malleolar fractures because of the adjacent position of the peroneal tendons relative to the lateral malleolus. Complications stemming from this can lead to increased difficulty in reducing fibular fractures and subsequent shortening of the fibula. For the purpose of this article, we present 2 cases, 1 using open reduction with internal fixation and the other with external fixation. We will demonstrate that, in both reduction methods, lengthening of the peroneal tendons can be a useful adjunct procedure to aid in restoration of fibular length in diabetic ankle fractures.

Intraoperative tap test for coronal syndesmotic instability: A cadaveric study

INTRODUCTION

Precise diagnosis of distal tibiofibular syndesmotic injury is challenging, and a gold standard diagnostic test has still not been established. Tibiofibular clear space identified on radiographic imaging is considered the most reliable indicator of the injury. The Cotton test is the most widely used intraoperative technique to evaluate the syndesmotic integrity although it has its limitations. We advocate for a novel intra operative test using a 3.5 mm blunt cortical tap.

METHODS

Tibiofibular clear space was assessed in nine cadaveric specimens using three sequential fluoroscopic images. The first image was taken prior to the application of the tap test (intact, non-stressed). Then, a 2.5 mm hole was drilled distally on the lateral fibula, and a 3.5 mm cortical tap was then threaded in the hole. The tap test involved gradually advancing the blunt tip against the lateral tibia, providing a tibiofibular separation force (intact, stressed). This same stress was then applied after all syndesmotic ligaments were released (injured, stressed). Measurements were compared by one-way ANOVA and paired Student's t-test. Intra and inter-observer agreements were evaluated by intraclass correlation coefficient (ICC). P-values <.05 were considered significant.

RESULTS

We found excellent intra-observer (0.97) and inter-observer (0.98) agreement following the imaging assessment. Significant differences were found in the paired comparison between the groups (p < .05). When using an absolute value for TFCS >6 mm as diagnostic for coronal syndesmotic instability, the tap test demonstrated a 96.3% sensitivity and specificity, a 96.3% PPV and NPV and a 96.3% accuracy in diagnosing coronal syndesmotic instability.

CONCLUSIONS

Our cadaveric study demonstrated that this novel coronal syndesmotic instability test using a 3.5 mm blunt cortical tap is a simple, accurate and reliable technique able to demonstrate significant differences in the tibiofibular clear space when injury was present. It could represent a more controlled and stable alternative to the most used Cotton test.

Weber C ankle fractures with tibiofibular diastasis: syndesmosis-only fixation

OBJECTIVES:

To evaluate syndesmosis-only fixation in Weber C ankle fractures with tibiofibular diastasis and to assess the need for additional fibular fixation.

METHODS:

Twenty-one patients with Weber C ankle fractures and tibiofibular diastasis were followed for at least 24 months after treatment. In treatment of the Weber C fractures, only a syndesmosis screw was used through a mini open lateral incision if the syndesmosis could be anatomically reduced and fibular length and rotation could be restored. At follow-up, anteroposterior tibiofibular distance, lateral fibular distance, medial mortise distance and fracture healing were compared and patients were clinically evaluated using the Olerud and Molander ankle scale scoring system.

RESULTS:

The average duration of follow-up was 49 months and the decreases in anteroposterior tibiofibular distance and lateral fibular distance were statistically significant. At the last follow-up the average clinical score was 86. Ankle mortise was reduced at follow-up in all cases except one, which resulted in a late diastasis.

CONCLUSIONS:

Syndesmosis-only fixation can be an effective method of treating Weber type-C lateral malleolar fractures with syndesmosis disruption in cases where intraoperative fibular length can be restored and anatomical syndesmosis reduction can be achieved. Level of Evidence IV, Case Series.

Comparison of screw fixation with elastic fixation methods in the treatment of syndesmosis injuries in ankle fractures

17 patients with ankle syndesmosic injury were treated with a 4.5mm single cortical screw fixation (passage of screw 4 cortices) and 15 patients were treated with single-level elastic fixation material. All patients were evaluated according to the AOFAS ankle and posterior foot scale at the third, sixth and twelfth months after the fixation. The ankle range of movement was recorded together with the healthy side. The Student's t test was used for statistical comparisons. No statistical significant difference was observed between the AOFAS scores (p>0.05). The range of dorsiflexion and plantar flexion motion of the elastic fixation group at the 6th and 12th months were significantly better compared to the screw fixation group (p<0.01). Elastic fixation is as functional as screw fixation in the treatment of ankle syndesmosis injuries. The unnecessary need of a second surgical intervention for removal of the fixation material is another advantageous aspect of this method of fixation.

Evaluation of the syndesmotic-only fixation for Weber-C ankle fractures with syndesmotic injury

BACKGROUND

With the length of the fibula restored and the syndesmosis reduced anatomically, internal fixation using a plating device may not be necessary for supra-syndesmotic fibular fractures combined with diastasis of inferior tibio-fibular joint. A retrospective observational study was performed in patients who had this injury pattern treated with syndesmosis-only fixation.

MATERIALS AND METHODS

12 patients who had Weber type-C injury pattern were treated with syndesmosis only fixation. The treatment plan was followed only if the fibular length could be restored and if the syndesmosis could be anatomically reduced. Through a percutaneous or mini-open reduction and clamp stabilization of the syndesmosis, all but one patient had a single tricortical screw fixation across the syndesmosis. Patients were kept non-weight-bearing for 6 weeks, followed by screw removal at an average of 8 weeks. Outcomes were assessed using an objective ankle scoring system (Olerud and Molander scale) and by radiographic assessment of the ankle mortise.

RESULTS

At a mean follow-up of 13 months, the functional outcome score was 75. Excellent to good outcomes were noted in 83% of the patients. Ankle mortise was reduced in all cases, and all but one fibular fracture united without loss of fixation. Six patients had more than one malleolar injury, needing either screw or anchor fixations. One patient had late diastasis after removal of the syndesmotic screw and underwent revision surgery with bone grafting of the fibula. This was probably due to early screw removal, before union of the fibular fracture had occurred.

CONCLUSION

We recommend syndesmosis-only fixation as an effective treatment option for a combination of syndesmosis disruption and Weber type-C lateral malleolar fractures.

Mid-diaphyseal fibular fractures with syndesmotic disruption: should we plate the fibula?

BACKGROUND

The treatment of mid-diaphyseal fibula fractures with syndesmotic disruption is controversial. The purpose of this study was to compare the biomechanical properties of 2 fixation constructs.

MATERIALS AND METHODS

Eight pairs of human cadaveric legs were divided into two groups, both of which had midshaft fibular osteotomies and disruption of all ligamentous support up to the osteotomy level. In Group I, the left legs were fixed with only a 3.5-mm tricortical syndesmotic screw. In Group II, the right legs received this syndesmotic fixation in addition to plating of the fibula. Rotational stability was tested on each ankle in the intact, repaired, and post-cyclical load conditions. Each specimen was ultimately tested to failure in external rotation.

RESULTS

The rotational stability, load to failure, and stiffness were all found to be significantly higher with the plate and syndesmotic fixation repair technique (Group II) than with the syndesmotic fixation only technique (Group I). Furthermore, fixation in Group II improved rotational stability both before and after cyclic loading.

CONCLUSION

Improved biomechanical properties were found with fibular plating in addition to a syndesmotic screw in a midshaft fibular fracture model with syndesmotic and deltoid injury.

CLINICAL RELEVANCE

This information may be helpful in the decision-making process to optimally treat patients with this fracture pattern.