Suture button versus syndesmotic screw in ankle fractures - evaluation with 3D imaging-based measurements

Background Inadequate reduction of syndesmotic injuries can result in disabling clinical outcomes. The aim of the study was to compare syndesmosis congruity after fixation by syndesmotic screws (SYS) or a suture button system (SBS) using three-dimensional (3D) computed imaging techniques. Methods In a retrospective single-center study, patients with unilateral stabilization of an ankle fracture with a syndesmotic injury and post-operative bilateral CT scans were analyzed using a recently established 3D method. The side-to-side differences were compared for tibio-fibular clear space (∆CS), translation angle (∆α), and vertical offset (∆z) among patients stabilized with syndesmotic screws or suture button system. Syndesmotic malreduction was defined for ∆CS > 2 mm and for |∆α| > 5°. ∆CS and ∆α were correlated with two-dimensional (2D) measurements. Results Eighteen patients stabilized with a syndesmosis screw and 29 stabilized with a suture button system were analyzed. After stabilization, both groups revealed mild diastasis (SYS: mean ∆CS 0.3 mm, SD 1.1 mm vs SBS: mean ∆CS 0.2 mm, SD 1.2 mm, p = 0.710). In addition, both stabilization methods showed slight dorsalization of the fibula (SYS: mean ∆α 0.5°, SD 4.6° vs SBS: mean ∆α 2.1°, SD 3.7°, p = 0.192). Also, restoration of the fibula-to-tibia length ratio also did not differ between the two groups (SYS: mean Δz of 0.5 mm, SD 2.4 mm vs SBS: mean Δz of 0 mm, SD 1.2 mm; p = 0.477). Malreduction according to high ∆α was most common (26% of cases), with equal distribution between the groups (p = 0.234). ∆CS and ∆α showed good correlation with 2D measurements (ρ = 0.567; ρ = 0.671). Conclusion This in vivo analysis of post-operative 3D models showed no differences in immediate post-operative alignment after syndesmotic screws or suture button system. Special attention should be paid to syndesmotic malreduction in the sagittal orientation of the fibula in relation to the tibia in radiological control of the syndesmotic congruity as well as intra-operatively.

BMI and Comorbidities in Patients with Syndesmosis Screw Breakage

Category: Ankle; Trauma Introduction/Purpose: Syndesmosis screw fixation remains a common standard of care in patients with syndesmosis injuries. Post-operative screw breakage is a common occurrence in these patients. The purpose of this is study is to compare BMI, comorbidities, and characteristics of patients who had a syndesmosis injury repaired with screw fixation resulting in screw failure. Numerous studies (21) have examined patients with syndesmosis screw fracture, focusing primarily on screw characteristics such as width, length, and screw material. Of those studies, only six considered BMI, while only one of the six differentiated BMI between patients with a broken screw and those without. Only three of the studies collected patient comorbidity data. Methods: This study examined all tibia procedures at a level 1 trauma center from 2008 to 2019. Only patients treated with syndesmosis screw fixation that resulted in a screw fracture were included for further analysis. In total, 14 patients satisfied this criterion. A comprehensive analysis of each patients BMI, comorbidities, and characteristics was then performed. Age, gender, height, weight, BMI, smoking status, diabetes, hypertension, alcohol abuse, and soft tissue conditions were all analyzed. Further examination of conditions with potential to impact bone quality such as osteoporosis, osteoarthritis, and rheumatoid arthritis were also included. Results: Eight females and 6 males with an average age of 42.43±13.90(20-43) were included in the analysis. The average number of comorbidities was 2.93±(0-6). BMI average was 38.92±(22.05-56.34) indicating Grade II obesity for the entire patient cohort. Six patients had a BMI > 40 or Grade III (morbidly obese) while only two patients had a satisfactory BMI < 25. All patients in the syndesmosis fracture group had more than one comorbidity apart from a single patient (case 3). Six patients had at least 2 comorbidities, 3 patients had 3, 2 patients had 2, and 2 patients had 6. Eight (57%) of 14 had post-operative complications including: Symptomatic hardware + removal (6), revision surgery (4), and compartment syndrome (1). Five patients retained their broken screw without complication. Conclusion: Patients with syndesmosis screw breakage are a highly comorbid population. Patients in this study, on average, had a significantly elevated BMI potentially predisposing them to screw failure. In conclusion, future analysis of syndesmosis injuries should include BMI and comorbidities. Future studies should pay special attention to BMI as potential confounding variable when attempting to determine reasons for syndesmosis screw breakage. [Table: see text]

Syndesmosis Screw Breakage: An Analysis of Current Literature

Category: Ankle; Trauma Introduction/Purpose: Syndesmosis screw fracture is a common occurrence post syndesmosis screw fixation. The purpose of this study is to analyze all studies that include syndesmosis injury fixed with syndesmosis screws based on patient, screw, and surgical/rehabilitation characteristics. An emphasis will be placed on patients who suffered syndesmosis screw fracture following fixation. To date, no review has examined patient, screw, and surgical/rehabilitation characteristics with an emphasis on screw fractures in this patient population. Methods: Of the 482 articles assessed for eligibility, a total 52 articles were selected for full-text review. Following further inclusion criteria requirement 21 articles were included in the study. Each study was analyzed based on patient, screw, and surgical/rehabilitation characteristics. Patient demographics and comorbidities of gender, age, BMI, smoking, alcohol abuse, diabetes, soft tissue conditions were included. Screw characteristics that were included were screw material, number of screws, screw width, number of cortices, and number of patients with screw fracture (screw fracture rate). Surgical/rehabilitation characteristics included ankle position, screw placement above tibial plafond, screw angle, routine removal, rehabilitation process, and time to full weight bearing. Results: A total of 1,196 patients, 761 men and 440 females, were included in the analysis. The average number of patients in each study was 59.80±39.41(12-161). Comprehensive screw, surgical, and rehabilitation + outcome data can be seen in Table 1, 2, and 3, respectively. Nine studies reported on ankle position during surgery; dorsiflexion was the most common. Fourteen reported on placement of the screw above the tibial plafond, with 2 cm being the most common. Five reported on screw angle. 141 patients had a fractured screw(s). The average fracture rate was 11.41%. Five of the 21 studies reported BMI. Three studies stratified data comparing broken screw versus intact screw patients. Five reported on diabetes, one on alcohol abuse, and one study reported on comorbidities. Conclusion: In conclusion, analysis of syndesmosis screw fracture patients versus those with no fracture was difficult due to lack of differentiation in almost all the studies. Notably, syndesmosis screw fracture studies under report patient characteristics, specifically BMI. Comorbidities, especially BMI, are potential cofounding variables within this patient population and could contribute to screw failure. Future studies should include both BMI and comorbidities when analyzing patients whose syndesmosis fixation resulted in screw breakage.

Analysis of 28 Broken Syndesmosis Screws

Category: Ankle; Trauma Introduction/Purpose: Syndesmosis screw fixation remains a common standard of care in patients with syndesmosis injuries. Screw fracture is a relatively common occurrence in these patients. The purpose of this is study is to examine the screw characteristics of 28 syndesmosis screws that resulted in screw breakage. Methods: This retrospective study examined all tibia procedures from 2008 to 2019 at a level 1 trauma center. Patients that were treated with a syndesmosis screw that resulted in a screw breakage were included for further analysis. In total, 14 patients satisfied this criterion. A comprehensive analysis of the screw characteristics was then performed. Screw angle was determined using the fibular plate as the vertical axis. Distance of screw fracture also used the fibular plate as a reference point. The tibial plafond was used to determine screw placement. Screws were stratified into subcategories based on standard deviation for screw angle and screw placement. Results: 28 screws were analyzed in 14 patients (6 males, 8 females). On average, 2 syndesmosis screws were placed with a range of 1 to 4. Average screw length was 50.54±5.67 (45-65) mm. Average screw width was 3.64±.36 (3.50-4.50). Average angle of screw placement was 88.70±(65.90-99.50). Eighteen (64.29%) of the screws were placed at an angle greater than 90 degrees. Six were between 80-90 (21.42%) degrees. Average height above the tibial plafond was 25.90±(9.75-49.90). Fifteen (53.57%) of the screws were placed between 20-30mm above the tibial plafond. Six (21.43%) were between 10-20 mm. Twelve screw fractures occurred within the fibula, 7 within the tibia, and 2 screws had a fracture within the fibula and tibia. The average fracture distance from the fibular plate was 14.81±2.36(0-36.23) mm. Conclusion: The aim of this study was to examine syndesmosis screw characteristics following fracture. Eighteen of the 28 screws were placed above a 90-degree angle and 15 were placed between 20-30mm above tibia plafond. This may suggest higher risk for screw fracture above 90 degrees and between 20-30mm above the tibial plafond, however, further analysis with more subjects should be done before any determination is made. [Table: see text]

Revision of Syndesmosis Screw Fixation

Background: Many syndesmosis screw fixations do not achieve success at the first attempt. Currently, there are no data available to evaluate revision of syndesmosis screw failure. Methods: A total of 160 consecutive patients who underwent syndesmosis screw fixation from 2014 to 2016 were reviewed. The current study focuses on 13 of 160 patients who underwent revision surgery and analyzes reasons, methods, and outcomes of syndesmotic screw revisions. Results: Thirteen out of 160 patients had revision surgeries. Incidence of recurrent diastasis was 92.3%. Seven out of 19 screws had broken. Two patients had screw loosening, 9 patients underwent early weightbearing, 1 patient developed osteomyelitis, 1 patient developed osteoarthritis, and 1 patient had fibular nonunion. Eleven patients underwent removal, 3 patients underwent clamp reduction, and 4 patients underwent fibular osteotomy. Six patients experienced good reduction with 0/10 pain, 3 patients experienced good reduction with some pain, 1 patient experienced poor reduction; 1 patient developed osteomyelitis and subsequent 7/10 pain; 1 patient underwent fusion with 5/10 pain, and 1 patient experienced medial malleolar mal-union with 3/10 pain. Conclusion: It was found that the main reason for syndesmosis revision was reoccurring diastasis. Most patients ultimately experienced good reduction and were able to ambulate, despite some residual pain. Levels of Evidence: Level IV: Case series

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

ABSTRACT 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.