Changes in the syndesmotic reduction after syndesmotic screw fixation for ankle malleolar fractures: One-year longitudinal evaluations using computer tomography

IntroductionTo evaluate time-dependent changes in the syndesmotic reduction after syndesmotic screw fixation and one year after screw removal for ankle malleolar fractures, and to assess whether the incidence of syndesmotic malreduction changes depending on the measurement method.MethodsWe assessed twenty patients who underwent syndesmotic screw fixation for ankle fractures. The syndesmotic screws were removed after six weeks of the fracture surgery. Syndesmotic reduction was assessed within two weeks of the fracture surgery and one year after the screw removal using the axial computer tomographic images. Side-to-side differences in the anterior and posterior tibiofibular distances, anteroposterior fibular translation, and fibular rotation were measured.ResultsThe mean anterior tibiofibular distance was 0.7 mm after syndesmotic fixation. It increased to 1.9 mm at one year after screw removal (p = 0.002). After syndesmotic fixation, four ankles had malreduction of the anterior tibiofibular distance, including three ankles with widening and one with overtightening. At one year, eight ankles had malreduction, all of whom had widening. The other measurement values did not change over time (0.1 mm vs. 0.6 mm for the posterior tibiofibular distance, 0.2 mm vs. 0.3 mm for the anteroposterior fibular translation, and 0.7 ° vs. 0 ° for the fibular rotation). The incidences of malreduction were significantly different depending on the definition of malreduction, ranging from 10% to 50% after syndesmotic fixation (p = 0.01) and from 20% to 60% at one year after screw removal (p = 0.02).ConclusionsThe anterior tibiofibular distance widened after one year of syndesmotic screw removal. The incidence of malreduction varied depending on the measurement method.     

The isolated posterior malleolar fracture and syndesmotic instability: A case report and review of the literature

IntroductionAnkle fractures are among the most common type of fractures in the lower extremity. A posterior malleolar fracture is frequently part of a more complex ankle fracture and only in rare cases it occurs as isolated injury. Posterior malleolar fractures often occur with associated injuries, such as a Maisonneuve fracture or with bi- or trimalleolar ligamentous injuries. Knowledge about these associated injuries is essential to prevent missed diagnoses. The aim of this article is to describe the isolated posterior malleolar fracture, the possible associated injuries, the diagnostic work-up and therapeutic consequences.Presentation of caseWe present a case of a 26-year-old male patient who sustained an isolated posterior malleolar fracture with 4.5 years follow-up.DiscussionIsolated fractures of the posterior malleolus are uncommon injuries. Diagnosis, treatment and outcome can seldom be extracted from large series. However, several cases have been described in literature, which we have summarized.ConclusionThis case report and literature review shows that isolated posterior malleolar fractures might occur as part of a more complex ankle injury, in combination with a fracture of the lower leg or after high energy trauma. Physicians should be aware of these associated injuries. Diagnostic work-up should include X-rays of the knee and lower leg and a CT scan of the ankle. If diagnosed and treated properly, isolated posterior malleolar fractures have a good long-term functional outcome.     

Intraoperative tap test for coronal syndesmotic instability: A cadaveric study

IntroductionPrecise 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.MethodsTibiofibular 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.ResultsWe 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.ConclusionsOur 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.     

Anterior-inferior tibiofibular ligament anatomical repair and augmentation versus trans-syndesmosis screw fixation for the syndesmotic instability in external-rotation type ankle fracture with posterior malleolus involvement: A prospective and comparative study

PurposeSyndesmosis injury is common in external-rotation type ankle fractures (ERAF). Trans-syndesmosis screw fixation, the gold-standard treatment, is currently controversial for its complications and biomechanical disadvantages. The purpose of this study was to introduce a new method of anatomically repairing the anterior-inferior tibiofibular ligament (AITFL) and augmentation with anchor rope system to treat the syndesmotic instability in ERAF with posterior malleolus involvement and to compare its clinical outcomes with that of trans-syndesmosis screw fixation.Methods53 ERAFs with posterior malleolus involvement received surgery, and the syndesmosis was still unstable after fracture fixation. They were randomised into screw fixation group and AITFL anatomical repair with augmentation group. Reduction quality, syndesmosis diastasis recurrence, pain (VAS score), time back to work, Olerud–Molander ankle score and range of motion (ROM) of ankle were investigated.ResultsOlerud–Molander score in AITFL repair group and screw group was 90.4 and 85.8 at 12-month follow-up (P > 0.05). Plantar flexion was 31.2° and 34.3° in repair and screw groups (P = 0.04). Mal-reduction happened in 5 cases (19.2%) in screw group while 2 cases (7.4%) in repair group. Postoperative syndesmosis re-diastasis occurred in 3 cases in screw group while zero in repair group (P > 0.05). Pain score was similar between the two groups (P > 0.05). Overall complication rate and back to work time were 26.9% and 3.7% (P = 0.04), 7.15 months and 5.26 months (P = 0.02) in screw group and repair group, respectively.ConclusionsFor syndesmotic instability in ERAF with posterior malleolus involvement, the method of AITFL anatomical repair and augmentation with anchor rope system had an equivalent functional outcome and reduction, earlier rehabilitation and less complication compared with screw fixation. It can be selected as an alternative.     

Diagnosing syndesmotic instability in ankle fractures

The precise diagnosis of distal tibiofibular syndesmotic ligament injury is challenging and a distinction should be made between syndesmotic ligament disruption and real syndesmotic instability. This article summarizes the available evidence in the light of the author's opinion. Pre-operative radiographic assessment, standard radiographs, computed tomography scanning and magnetic resonance imaging are of limited value in detecting syndesmotic instability in acute ankle fractures but can be helpful in planning. Intra-operative stress testing, in the sagittal, coronal or exorotation direction, is more reliable in the diagnosis of syndesmotic instability of rotational ankle fractures. The Hook or Cotton test is more reliable than the exorotation stress test. The lateral view is more reliable than the AP mortise view because of the larger displacement in this direction. When the Hook test is used the force should be applied in the sagittal direction. A force of 100 N applied to the fibula seems to be appropriate. In the case of an unstable joint requiring syndesmotic stabilisation, the tibiofibular clear space would exceed 5 mm on the lateral stress test. When the surgeon is able to perform an ankle arthroscopy this technique is useful to detect syndesmotic injury and can guide anatomic reduction of the syndesmosis. Many guidelines formulated in this article are based on biomechanical and cadaveric studies and clinical correlation has to be established.     

Ankle stability in ankle fracture

Restoration of normal ankle kinematics should be the all-encompassing ethos in the approach to management of ankle fractures. To do this, the ligamentous stabilisers must also form part of its assessment and definitive management and be considered during index fracture fixation surgery. This article is a review of the anatomy, mechanics and clinical testing of instability in ankle fractures.     

踝关节慢性前外侧不稳的手术治疗

目的: 探讨治疗踝关节慢性前外侧不稳定 (踝关节外侧不稳定合并距下关节不稳定) 的合理而有效的手术方式。方法: 自 1999 ~2003年, 应用Chrisman Snook术式, 以腓骨短肌腱前半部分重建距腓前韧带、跟腓韧带和距跟外侧韧带,治疗踝关节慢性前外侧不稳 8例患者,共 13例关节。结果: 术后随诊 6个月~5年, 平均 19个月。术后所有踝关节均达到功能稳定, 关节活动度基本恢复正常, 没有复发性踝关节不稳发生。以Good评级标准作为疗效评价, 10例关节 (77% ) 为优, 2例关节 (15% ) 为良, 1例关节为中 (7% ), 优良率达 92%。结论: Chrisman Snook术式重建了距腓前韧带、跟腓韧带和距跟外侧韧带, 有效地矫正了踝关节外侧不稳定和距下关节不稳定, 是治疗踝关节慢性前外侧严重不稳定的合理而有效的治疗方法。     

A rare type of ankle fracture: Syndesmotic rupture combined with a high fibular fracture without medial injury

High fibular spiral fractures are usually caused by pronation-external rotation mechanism. The foot is in pronation and the talus externally rotates, causing a rupture of the medial ligaments or a fracture of the medial malleolus. With continued rotation the anterior and posterior tibiofibular ligament will rupture, and finally, the energy leaves the fibula by creating a spiral fracture from anterior superior to posterior inferior.In this article we demonstrate a type of ankle fracture with syndesmotic injury and high fibular spiral fractures without a medial component. This type of ankle fractures cannot be explained by the Lauge-Hansen classification, since it lacks injury on the medial side of the ankle, but it does have the fibular fracture pattern matching the pronation external rotation injury (anterior superior to posterior inferior fracture). We investigated the mechanism of this injury illustrated by 3 cases and postulate a theory explaining the biomechanics behind this type of injury.     

慢性踝关节不稳诊断与治疗的研究进展

慢性踝关节不稳常由急性踝关节扭伤漏诊或者治疗不当所致,可以导致局部长期疼痛,继发踝关节创伤性关节炎甚至功能障碍等一系列问题,是种常见但治疗相对棘手的疾病。但是对于其诊断与治疗尚没有统一的标准。应力下X线、MRI及超声等检查方式众多,哪种才是疾病诊断过程中的首选或是金标准。在疾病的治疗过程中,手术是治疗严重踝关节不稳的主要手段,但现有的手术方式疗效差别较大,理念也不尽一致,使临床医师选择手术方式时存在较大的困惑。近年来文献报道的手术治疗方式已由原有的非解剖重建逐渐向原位解剖重建转变。     

Angle bisector method to determine the accurate angle for tibiofibular syndesmotic fixation: A validation study with 3D-printed anatomical models

PurposeThis study aimed to validate the angle bisector method on 3D-printed ankle models to reveal whether it aids in placing syndesmotic screws at an accurate trajectory that is patient- and level-specific and also not surgeon-dependent.MethodsDICOM data of 16 ankles were used to create 3D anatomical models. Then the models were printed in their original size and two trauma surgeons performed the syndesmotic fixations with the angle bisector method at 2 cm and 3.5 cm proximal to joint space. Afterward, the models were sectioned to reveal the trajectory of the screws. The photos of the axial sections were processed in a software to determine the centroidal axis which is defined as true syndesmotic axis and analyze its relationship with the screws inserted. The angle between the centroidal axis and syndesmotic screw was measured by two-blinded observers 2 times with 2 weeks interval.ResultsThe average angle between the centroidal axis and screw trajectory was 2.4° ± 2° at 2 cm-level and 1.3° ± 1.5° at 3.5 cm-level, indicating a reliable direction with minimal differences at both levels. The average distance between fibular entry points of the centroidal axis and screw trajectory was less than 1 mm at both levels indicating that the angle bisector method can provide an excellent entry point from fibula for syndesmotic fixation. The inter- & intra-observer consistencies were excellent with all ICC values above 0.90.ConclusionThe angle bisector method provided an accurate syndesmotic axis for implant placement which is patient- & level-specific and not surgeon-dependent, in 3D-printed anatomical ankle models.     

Prognostic factors for intermediate-term clinical outcomes following Bosworth fractures of the ankle joint

BackgroundThis retrospective comparative study was performed to evaluate the clinical outcomes after surgical treatment for Bosworth fracture-dislocation, and to analyse the prognostic factors related to postoperative outcomes.MethodsFifteen patients were followed for ≥2 years after Bosworth fracture-dislocation. Twenty-five ankle fracture-dislocations as control group were enrolled to compare clinical outcomes. Clinical evaluation consisted of the AOFAS and Olerud–Molander scores. Patient and injury factors were analysed to identify the outcome predictors.ResultsThere were no significant differences in either clinical evaluation score as compared to control group (P = 0.245, .302, respectively). The time interval to operation and number of manual reduction attempts were found to be predictive factors for poor outcomes (P = 0.004, .038, respectively).ConclusionAs compared to more common patterns of ankle fracture-dislocations, intermediate-term clinical outcomes after Bosworth fracture-dislocations were statistically comparable. Delayed surgical reduction and repeated attempts at closed reduction appear to be negative outcome predictors.     

The feasibility of point-of-care ankle ultrasound examination in patients with recurrent ankle sprain and chronic ankle instability: Comparison with magnetic resonance imaging

ObjectiveTo evaluate the feasibility of point-of-care ankle ultrasound compared with magnetic resonance imaging (MRI) for diagnosing major ligaments and Achilles tendon injuries in patients with recurrent ankle sprain and chronic instability, and to evaluate inter-observer reliability between an emergency physician and a musculoskeletal radiology fellow.Material and methodsA prospective cross-sectional study was conducted in an emergency department. Patients with recurrent ankle sprain and chronic instability were recruited. An emergency physician and a musculoskeletal radiology fellow independently evaluated the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), distal anterior tibiofibular ligament (ATiFL), deltoid ligament, and Achilles tendon using point-of-care ankle ultrasound. Findings were classified normal, partial tear, and complete tear. MRI was used as the reference standard. We calculated diagnostic values for point-of-care ankle ultrasound for both reviewers and compared them using DeLong's test. Intra-class correlation coefficients (ICCs) were calculated for agreement between each reviewer and the reference standard, and between the two reviewers.ResultsEighty-five patients were enrolled. Point-of-care ankle ultrasound showed acceptable sensitivity (96.4–100%), specificity (95.0–100%), and accuracy (96.5–100%); these performance markers did not differ significantly between reviewers. Agreement between each reviewer and the reference standard was excellent (emergency physician, ICC = 0.846–1.000; musculoskeletal radiology fellow, ICC = 0.930–1.000), as was inter-observer agreement (ICC = 0.873–1.000).ConclusionPoint-of-care ankle ultrasound is as precise as MRI for detecting major ankle ligament and Achilles tendon injuries; it could be used for immediate diagnosis and further pre-operative imaging. Moreover, it may reduce the interval from emergency department admission to admission for surgical intervention, and may save costs.     

Incidence and risk factors of occult posterior malleolar fracture in patients with spiral distal tibial fracture: Reexamination and analysis

ObjectiveTo evaluate the incidence and risk factors for posterior malleolar fractures (PMFs) in patients with spiral distal tibial fractures (SDTFs).MethodsIn a retrospective study, 248 adults with SDTFs who underwent treatment were enrolled between November 2017 and May 2020. In a prospective study, we recruited 113 consecutive, skeletally mature patients with SDTFs who were identified from the trauma clinic of our hospital between June 2020 and May 2021. Radiographs and CT scans of the ankle region on the affected side were obtained to determine the presence of PMFs. If the CT scan was negative, additional MRI examination of the ankle was performed as a supplementary protocol in the prospective study. Univariate analysis and multivariate analysis were conducted to analyze the risk factors.ResultsIn the retrospective study, the incidence of PMFs associated with simple SDTFs was 74.0% (105/142), which was significantly lower than 90.8% (69/76) in the prospective study. Independent predictors of PMFs in patients with simple SDTFs identified by multivariate analysis in the retrospective study were age (OR = 1.07; P = 0.001) and external rotation of the proximal tibia (OR = 3.36; P = 0.027) and those in the prospective study were osteoporosis (OR = 0.04; P = 0.007) and spiral fibula fractures (OR = 16.05; P = 0.046).ConclusionThis study reexamined the high incidence of concurrent PMFs. Additionally, ankle radiographs and CT scans were recommended for all simple SDTF patients. For simple SDTF patients with negative CT scans, especially those caused by external rotation of the proximal tibia, combined with nonosteoporotic or spiral fibula fractures, additional MRI examinations are recommended.     

手术治疗慢性踝关节外侧不稳106例

目的探讨慢性踝关节外侧不稳继发病损及其有效的手术方法。方法 本组行手术解剖重建外踝韧带治疗慢性踝关节外侧不稳的患者106例,观察其继发病损在关节镜下的表现。结果 对本组患者随访12～111个月,平均31.2个月,术后所有踝关节均达到功能稳定,关节活动度基本恢复正常,没有复发性踝关节不稳发生。运用美国AOFAS足踝评分系统对患者手术前后踝关节功能进行评估,术前与术后AOFAS后足评分间的差异有统计学意义。结论 解剖重建距腓前韧带、跟腓韧带,有效地矫正了踝关节外侧不稳定和距下关节不稳定,是治疗踝关节慢性前外侧严重不稳定的合理而有效的治疗方法。     

关节镜联合韧带缝合治疗外踝不稳的短期疗效

目的随访采用关节镜手术联合小切口辅助下缝合距腓前韧带缝合术式治疗的患者,分析此术式治疗慢性外踝不稳的近期疗效,为进一步推广应用提供依据。 方法回顾性随访自2016年1月至2018年5月,选择保守治疗无效的踝关节机械性不稳患者,排除功能性不稳、足踝部畸形等其他病史的患者。共纳入了西南医院关节外科63例应用关节镜手术联合韧带缝合术治疗慢性外踝不稳的患者。记录围手术期并发症,采用配对t检验分析术前与术后1年以上末次随访的踝关节视觉模拟疼痛(VAS)评分、美国足踝骨科协会踝与后足(AOFAS)评分。 结果患者末次随访较术前踝关节VAS评分、AOFAS评分明显改善,差异有统计学意义(t＝17.8、20.8,两者均P<0.01)。关节镜手术探查发现：合并软组织撞击征47例,撕脱性骨折24例,前踝骨性撞击征11例,距骨软骨损伤8例,关节游离体8例,腓骨肌腱脱位1例。患者术后均无严重并发症。 结论关节镜手术联合韧带缝合术治疗慢性外踝不稳,可以获得较理想的近期疗效。该联合方案,既可以应用关节镜微创术处理踝关节内合并损伤,又可以使用锚钉技术缝合距腓前韧带,具有操作相对简单,并发症低的优势。     

一期韧带修复联合拉力螺钉固定治疗踝关节不稳的疗效观察

目的：探讨一期韧带修复联合拉力螺钉固定治疗踝关节不稳的临床疗效。方法回顾性分析2011年1月至2013年6月间我科收治的34例急性踝关节外侧扭伤患者,男18例,女16例,年龄28.0~69.0岁,平均(49.3±1.9)岁。随机分为螺钉固定组和外固定组,每组各17例,分别采用一期带线铆钉原位修补联合拉力螺钉固定(螺钉固定组)和石膏或支具外固定治疗(外固定组)。所有患者术后患肢不负重,随访3个月,观察两组住院费用及并发症发生情况,根据美国足踝外科协会( American Orthopaedic Foot and Ankle Society,AOFAS)踝与后足功能评分及视觉模拟评分法( visual analogue score, VAS)评价两种方法的治疗效果。结果螺钉固定组住院费用为(1.72±0.30)万元,外固定组为(0.68±0.20)万元,差异有统计学意义(P<0.05)。术后1、2、3个月随访AOFAS踝与后足评分,螺钉固定组为(66.2±1.3)分、(88.5±2.1)分、(97.2±1.9)分,外固定组为(46.8±1.6)分、(53.5±2.7)分、(75.6±1.2)分,差异有统计学意义(P<0.05)。采用VAS评分：螺钉固定组为(3.2±0.8)分、(2.5±0.6)分、(1.2±0.2)分,外固定组为(4.0±0.7)分、(3.1±0.6)分、(2.6±0.4)分,差异有统计学意义(P<0.05)。螺钉固定组所有患者术后未发生螺钉切出、断钉、创伤性关节炎、下胫腓不稳等并发症,外固定组中2例出现踝关节僵硬,经功能锻炼和物理疗法后有所缓解,4例术后3个月因疼痛和踝关节不稳二期行韧带重建术,恢复可。结论一期韧带修复联合拉力螺钉固定治疗急性踝关节不稳虽然住院费用较高,但并发症少,术后踝关节功能佳,是临床治疗踝关节扭伤的一种可行术式。     

Functional outcomes of unstable ankle fractures with and without syndesmotic fixation in the adolescent population

PurposeThe purpose of this study was to compare functional outcomes of adolescents with and without ankle syndesmotic injuries and identify predictors of functional outcome after operative ankle fractures.MethodsA retrospective review was conducted on operative adolescent ankle fractures treated between 2009 and 2019 with a minimum of one-year follow-up (mean 4.35 years). Patients who underwent syndesmotic fixation (SF) (n = 48) were compared with operative ankle fractures without syndesmotic injury (n = 63). Functional outcomes were assessed using standardized questionnaires, specifically the Foot and Ankle Ability Measure (FAAM) and Single Assessment Numerical Evaluation.ResultsThere were no differences in patient-reported outcomes, rates of return to sport or complications between groups with and without SF. The SF group had a longer tourniquet time (p = 0.04), duration of non-weight-bearing (p = 0.01), more Weber C fibula fractures (p < 0.001), fewer medial malleolus fractures (p = 0.03) and more frequently underwent implant removal (p < 0.0001). Male sex, lower body mass index (BMI) and longer duration of follow-up were significant predictors of a higher FAAM sports score using multivariable linear regression. SF was not a predictor of functional outcome.ConclusionThis study demonstrated that patients that undergo surgical fixation of syndesmotic injuries have equivalent functional outcomes compared to operative ankle fractures without intraoperative evidence of syndesmotic injury. We also identified that male sex, lower BMI and longer duration of follow-up are predictors of a good functional outcome.Level of EvidenceIII