Effect of a Dynamic Fixation Construct on Syndesmosis Reduction: A Cadaveric Study

A comparison of screw and suture button fixation in the management of adolescent ankle syndesmotic injuries

Purpose

Ankle injuries involving the tibiofibular syndesmosis often necessitate operative fixation to restore stability to the ankle. Recent literature in the adult population has suggested that suture button fixation may be superior to screw fixation. There is little evidence as to which construct is preferable in the pediatric and adolescent population. This study investigates outcomes of suture button and screw fixation in adolescent ankle syndesmotic injuries.

Methods

A retrospective matched cohort study over 10 years of pediatric patients who underwent ankle syndesmotic fixation at a large Level 1 Trauma Center was conducted. Both isolated syndesmotic injuries and ankle fractures with syndesmotic disruption were included. Preoperative variables collected include basic patient demographics, body mass index, and fracture type. Suture button and screw cohorts were matched based on age, race, sex, and open fracture utilizing propensity scores. Outcomes assessed include reoperation and implant failure.

Results

A total of 44 cases of operative fixation of the ankle syndesmosis were identified with a mean age of 16 years. After matching cohorts based on age, sex, race, and open fracture status, there were 17 patients in the suture button and screw cohorts, respectively. Patients undergoing screw fixation had a six times greater risk of reoperation (p = 0.043) and 13 times greater risk of implant failure (p < 0.001). Out of six cases of reoperation in the screw cohort, five were unplanned.

Conclusion

Our findings favor suture button fixation in operative management of adolescent tibiofibular syndesmotic injuries. Compared with screws, suture buttons are associated with lower risk of both reoperation and implant failure.

Level of evidence

level III therapeutic.

Association of Periprosthetic Fibula Fracture With Knotless Suture Button (TightRope) Fixation for Ankle Syndesmosis in Elite Athletes

Background

Suture button fixation is frequently used to stabilize the distal tibiofibular syndesmosis in athletes sustaining an isolated ligamentous syndesmosis injury.

Purpose

To report on a series of periprosthetic fibula fractures adjacent to the lateral suture button after a subsequent unrelated ankle injury or progressive stress injury after initial ankle syndesmosis stabilization using the knotless TightRope (Arthrex).

Study Design

Case series; Level of evidence, 4.

Methods

Eight elite athletes with periprosthetic fibula fractures and stress injuries around the lateral suture buttons were evaluated. In all athletes, the knotless TightRope had been used to stabilize an isolated ligamentous ankle syndesmotic injury, after which all patients recovered and returned to professional sports at their preinjury level. The athletes subsequently developed an acute fibula fracture or a fibula stress fracture related to the 3.7-mm drill hole in the fibula adjacent to the lateral suture buttons after a mean of 14.1 months (range, 5-29 months). The management of these complications was analyzed.

Results

Five athletes sustained a periprosthetic fibula fracture in the form of undisplaced spiral Weber B injuries after a subsequent, unrelated injury. Poor healing response was noted with initial nonoperative treatment for the first 2 athletes, and surgical intervention was performed with successful union of the fracture and return to sports. The subsequent 3 athletes had early surgery with uneventful recovery. Another 3 athletes developed stress injuries adjacent to the fibula suture button without a history of acute trauma. In 2 of the 3 athletes, the position of lateral suture buttons was in the anterior third of the fibula. Initial nonoperative management yielded poor healing response, and subsequent surgical intervention was required to enable healing and return to sports.

Conclusion

Nonoperative management of fractures adjacent to the fibula suture button of a knotless TightRope may lead to a delay in union. Therefore, early surgical intervention should be considered in elite athletes, whose return-to-sports time is critical. Care is needed to ensure that the fibula hole for the suture button is centrally located because the eccentric placement of the fibula hole in the anterior third of the fibula may contribute to the development of a stress reaction or stress fracture. Surgical intervention for a periprosthetic fibula stress fracture leads to satisfactory resolution of symptoms.

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.

Compensation of Dynamic Fixation Systems in the Quality of Reduction of Distal Tibiofibular Joint in Acute Syndesmotic Complex Injuries: A CT-Based Analysis

BACKGROUND

There is an ongoing discussion on how to best stabilize syndesmotic injuries. Previous studies have indicated a better quality of reduction of the distal tibiofibular joint (DTFJ) for the suture button systems compared to syndesmotic screw fixation. Still, the reason for this superiority remains unclear. The aims of this retrospective study were to (1) analyze the deviation of the tibial and fibular drilling tunnels of the suture button system and (2) to compare these to the quality of reduction of the DTFJ assessed on bilateral postoperative CT images.

METHODS

Included were all adult patients who underwent syndesmotic stabilization for an acute injury using a suture button system, with postoperative, bilateral CT imaging over a 10-year period. A total of 147 patients were eligible. Based on individually reconstructed axial CT slices, the postoperative quality of reduction of the DTFJs was rated on bilateral CT images. Furthermore, the rotation and translation of the suture button drilling tunnels were analyzed. Based on these measurements, the intraoperative reduction of the DTFJ was recalculated and again rated. Using these values, the correction potential of suture button systems on the reduction of the DTFJ was analyzed.

RESULTS

(1) The drilling tunnel deviated considerably for both rotation |2.3±2.1 degrees| (range: |0.0-13.1 degrees|) and translation |0.9±0.8 mm| (range: |0-4.3 mm|). Based on the deviation of the drilling tunnels in fibula and tibia, the calculated intraoperative reduction of the DTFJ was classified as malreduced in 35.4%. (2) The DTFJ was postoperatively identified as malreduced in 17% of patients. Overall, the suture button system tended to compensate toward a more anatomical reduction both in the axial and sagittal plane.

CONCLUSION

A suture button system postoperatively deviates and apparently has the capacity to compensate for intraoperative malreduction. Analysis of the drilling tunnels revealed that the use of a rigid fixation system would have doubled the postoperative malreduction rate.

Biomechanical comparison of screw, tightrope and novel double endobutton in the treatment of tibiofibular syndesmotic injuries

BACKGROUND

Adequate reduction and stabilization of the syndesmosis are significant to prevent early degeneration of the ankle joint and get better clinical outcomes. However, the routine surgical methods have diffierent limitations. The purpose of this study was to develop a novel double Endobutton fixation to treat the distal tibiofibular syndesmotic injuries, and determine whether the novel double Endobutton fixation demonstrates a better biomechanical property compare with the intact syndesmosis, the screw fixation and the Tightrope fixation.

METHODS

Twenty-four normal fresh-frozen ankle specimens with a mean age of 42 ± 8 (range, 28-62) years were randomly divided equally into four groups: (1) the intact group, (2) the screw group, (3) the Tightrope group, (4) the Endobutton group. 3D printer technology was used to establish the personalized distal tibiofibular syndesmotic navigation modules to determine the accurate bone tunnel. Axial loading was applied in five ankle positions: neutral position, dorsiflexion, plantar flexion, varus and valgus. Rotation torque was applied in two ankle rotation of the neutral position: internal and external.

RESULTS

In most situations, the displacements of the intact group were larger than the screw group, the Tightrope group and the Endobutton group (P < .05), and the displacements of the screw group were smaller than other three groups (P < .05). The displacements of the double Endobutton group were slightly larger than the Tightrope group but no significant differences were found between these two groups except in the dorsiflexion position of axial loading experiments (P < .05). The novel double Endobutton fixation was steadier than intact syndesmosis and more micromotional than screw fixation.

CONCLUSION

Our study demonstrated that the novel double Endobutton can be considered as the better fixation in treatment of distal tibiofibular syndesmotic injuries.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Dual Suture Button Fixation With Buttress Plate for Ankle Syndesmotic Injury

SUMMARY

In this video, we present a unique approach to a purely ligamentous syndesmotic injury in a 16-year-old football player. Syndesmotic reduction was obtained using a large clamp and validated by matching fibular position to a fluoroscopic image of the contralateral ankle. Fixation was achieved using dual suture button devices in combination with a buttress plate. A small medial incision was used to protect the saphenous neurovascular bundle during button placement.

Suture-button Versus Screw Fixation in Adolescent Syndesmotic Injuries: Functional Outcomes and Maintenance of Reduction

BACKGROUND

Fixation of the tibiofibular syndesmosis is often performed with a trans-syndesmotic screw (SS) or suture-button (SB). SB fixation has been shown to have lower rates of postoperative syndesmotic malreduction, late diastasis, and implant removal, though some studies have found complications related to infection and implant subsidence. The purpose of this study was to compare maintenance of reduction, complications, implant removal and functional outcomes of SB versus SS fixation in adolescents.

METHODS

A retrospective chart review identified patients who underwent syndesmotic fixation from 2010 to 2019 at a single institution. Loss of syndesmotic reduction (diastasis) was defined as either a >2 mm increase in tibiofibular clear space or >2 mm decrease in tibiofibular overlap, and corresponding incongruence of the ankle mortise (medial clear space 1 millimeter greater than superior clear space). Functional outcomes were collected at a minimum of 1 year postsurgery using the Foot and Ankle Ability Measure (FAAM).

RESULTS

Seventy-seven adolescents (45 SS, 32 SB) were included (mean age: 16±1.5 y). Forty-five patients had Weber C fibula fractures, 27 Weber B fractures, and 5 had isolated syndesmotic injuries or small posterior malleolus fractures. Fifty-one patients (66%) had functional outcomes available. There was no significant difference in mean FAAM Sports score between the 2 groups (SB=94.8%, SS=89.8%) at mean follow-up of 4.0±2.1 years. Syndesmotic implant removal occurred in 36/45 patients (80%) in the SS group compared with 4/32 patients (13%) in the SB group. There was 1 case of syndesmotic malreduction requiring revision surgery in the SS group, and no cases of postoperative malreduction or diastasis in the SB group. Nine patients in the SB group and 8 in the SS group weighed over 100 kilograms, with no cases of diastasis in these larger patients. There were 4 superficial infections and 1 deep infection in the screw group, with 1 superficial infection in the SB group.

CONCLUSIONS

While both SB and screw fixation maintained syndesmotic reduction, SB fixation led to lower rates of implant removal surgery. SB fixation was equally effective at preventing recurrent diastasis in adolescents weighing over 100 kilograms, and functional outcomes were at least equivalent to screw-fixation at mean follow-up of 4.0 years.

LEVEL OF EVIDENCE

Level III.

Comparison of Suture-Button Versus Syndesmotic Screw in the Treatment of Distal Tibiofibular Syndesmosis Injury: A Meta-analysis

Traditionally screw fixation is an effective surgical procedure for the treatment of unstable syndesmosis injuries. However, it is still a controversy whether suture-button (SB) device can achieve better clinical outcomes and decrease the risk of complications compared with syndesmotic screw (SS). The present meta-analysis was conducted to figure out whether SB fixation was superior to traditionally screw fixation. Twelve clinical studies were identified, involving 320 patients in the SB group and 334 patients in the SS group. Among patients treated with SB, the American Orthopaedic Foot & Ankle Society (AOFAS) score was significantly higher at 3-month follow-up (p = .01) and 2-year follow-up (p = .02), and the Olerud-Molander Ankle (OMA) score at 1-year follow-up (p = .002). In addition, the SB group had significantly better results in the malreduction (p = .0008), implant failure (p < .01), implant removal (p < .01), and local irritation (p = .004). No statistical differences were found in the AOFAS at 6 months follow-up (p = .33) and 1-year follow-up (p = .33), OMA at 3 months follow-up (p = .09), 6 months follow-up (p = .14) and 2 years follow-up (p = .36), the Foot and Ankle Disability Index (p = .73), Euro Qol 5-dimension questionnaire (p = .33), dorsiflexion (DF; p = .91), plantarflexion (p = .23), medial clear space (p = .42), tibiofibular clear space (p = .60), tibiofibular overlap (p = .84), and other complications (p = .95). Based on this meta-analysis, there was no significant difference in postoperative radiological measurements, and no sufficient evidence was found to support the improved clinical outcomes compared with SS fixation group. However, SB technique could improve functional outcomes, reduce the rate of implant removal, implant failure, local irritation, and malreduction without increasing risk of other complications. Therefore, the SB technique should be recommended in the treatment of syndesmosis injuries.

Screw versus suture button in treatment of syndesmosis instability: Comparison using weightbearing CT scan

BACKGROUND

The superiority of screw or suture button fixation for syndesmotic instability remains debatable. Our aim is to compare radiographic outcomes of screw and suture button fixation of syndesmotic instability using weight bearing CT scan (WBCT).

METHODS

Twenty patients with fixation of unilateral syndesmotic instability were recruited and divided among two groups (screw = 10, suture button = 10). All patients had WBCT of both ankles ≥12 months postoperatively.

RESULTS

In suture button group, injured side measurements were significantly different from normal side for syndesmotic area (P = 0.003), fibular rotation (P = 0.004), anterior difference (P = 0.025) and direct anterior difference (P = 0.035). In screw group, syndesmotic area was the only significantly different measurement (P = 0.006).

CONCLUSION

While both screw and suture button didn't completely restore the syndesmotic area as compared to the contralateral uninjured ankle, external malrotation of the fibula was uniquely associated with suture button fixation.

LEVEL OF EVIDENCE

III Retrospective Cohort Study.

Biomechanical comparison of suture-button, bioabsorbable screw, and metal screw for ankle syndesmotic repair: A meta-analysis

BACKGROUND

To compare biomechanically metal screw fixation to suture-button or bioabsorbable screw fixation for ankle syndesmotic injuries.

METHODS

A literature search of the comparison studies in Pubmed and Google Scholar was conducted. The biomechanical outcomes of interest were syndesmotic stability in the coronal, sagittal, and axial planes as well as torque and rotation at failure.

RESULTS

A total of 11 cadaveric studies were included. In the suture-button group, coronal displacement (MD 1.72mm, p = 0.02) and sagittal displacement (MD 2.65mm, p = 0.0003) were increased relative to the metal screw group. In contrast, no difference was found with axial rotation (MD 0.35 degrees, p = 0.57). Bioabsorbable screws exhibited equivalent failure torque (MD -3.04Nm, p = 0.53) and rotation at failure (MD 3.77 degrees, p = 0.48) in comparison to metal screws.

CONCLUSIONS

Suture-button provide less rigidity when compared to metal screw fixation. They afford flexible syndesmotic micromotion which may more closely resemble a physiological state and be helpful for ligament healing. Bioabsorbable screws demonstrate similar mechanical strength properties to metal screws.

Strategies to Avoid Syndesmosis Malreduction in Ankle Fractures

Nearly half of surgically treated ankle fractures may have associated syndesmotic disruption, and the quality of reduction has been shown to affect functional outcomes. Malreduction ranges from 15% to 50% in the literature, and achieving anatomic reduction remains a significant challenge, even for experienced surgeons. Keys to success include having a stepwise plan and an understanding of reliable fluoroscopic parameters to help achieve reduction in both the coronal and sagittal planes. This article summarizes the literature on syndesmotic reduction and provides the authors' preferred technique using fluoroscopy.

Clinical Considerations to Reduce Saphenous Neurovascular Bundle Injury During Suture Button Fixation of Syndesmosis Injuries

OBJECTIVE

To document angles, from 2 difference starting points, or danger zones that should be avoided to minimize risk of injury or irritation to the saphenous neurovascular bundle (SNVB) during suture button (SB) fixation for distal tibiofibular syndesmosis injuries.

DESIGN

Retrospective imaging study.

SETTING

Academic Level 1 trauma center.

PATIENTS

Forty-eight randomly selected patients with healthy ankles and computed tomography scans for nonankle diagnoses.

MAIN OUTCOME MEASURES

Computed tomography scans and 3D reconstructed images were used to define the angle between the SNVB and 2 different fibular starting points, using the direct lateral (DL) and the posterolateral (PL) starting points. Descriptive analyses were performed to identify angles that should be avoided during suture button fixation. Distances from the SNVB using preset angles of 0, 10, 20, and 30 degrees were analyzed. In addition, the width of the SNVB, the midsubstance angle of the SNVB, and the distance from the 30-degree point to the tibialis anterior were recorded.

RESULTS

The mean angle between the SNVB and the standard DL starting point was 13.7 ± 5.0 degrees (P < 0.05), whereas the mean angle using the alternate PL starting point was 17.2 ± 5.3 degrees (P < 0.05). The SNVB width was 5.2 mm [range, 2.6-9.1 mm] (P < 0.05). The distances from the SNVB were greatest for the DL 30-degree group and the PL 0-degree group.

CONCLUSIONS

The results document angles that should be avoided when using suture button fixation for syndesmosis injuries. Device characteristics and surgery-related variables may require intraoperative modifications, and knowledge of this anatomical relationship may reduce SNVB injury during those situations. Considering our results, we recommend that surgeons place suture buttons from the DL starting point with a 30-degree trajectory to avoid injuries to the SNVB.