How to address the posterior malleolus in ankle fractures? A decision-making model based on the computerised tomography findings

Homeopathic Ankle Dislocation for Treatment of Unstable Trimalleolar Fractures Involving Posterior Die-Punch Fragment: A Retrospective Cohort Study

OBJECTIVES

Unstable trimalleolar fractures are relatively complex and more difficult to manage if die-punch fracture is present. We aimed to evaluate the curative effect of homeopathic ankle dislocation on the unstable trimalleolar fractures involving posterior die-punch fragments.

METHODS

A total of 124 patients diagnosed with unstable trimalleolar fractures combined with post-die punch fragment between June 2008 and June 2020 were retrospectively included. Patients who received homeopathic ankle dislocation were named as the experimental group, and patients who accepted conventional treatment were control group. The fracture healing time, wound healing, American Orthopedic Foot and Ankle Society ankle-hindfoot scale (AOFAS), visual analogue scale (VAS), the Kellgren-Lawrence arthritis grading scale (KLAGS) and short-form 36 score (SF-36) scores were collected. Student t-test was used for fracture healing time. Wound healing and SF-36 were compared using the Mann-Whitney test. Repeated measurement analysis of variance (ANOVA) was used for AOFAS and VAS. χ2-test was used for KLAGS.

RESULTS

AOFAS showed statistically significant differences between the two groups (p = 0.001). In non-weight-bearing and weight-bearing conditions, VAS scores were significant different between the two groups, and there was an interaction between group and time point (p < 0.001). The experimental group was superior to the control group in terms of physical function (p = 0.022), role-physical (p = 0.018), general health (p = 0.001) and social function (p = 0.042).The operation time of experimental group was shorter than that of control group (p < 0.001).

CONCLUSION

Homeopathic ankle dislocation is used for the unstable trimalleolar fractures involving posterior die-punch fragment, which can provide better functional outcomes while shortening the operation time and recovery period.

Safety and exposure area in three different posteromedial surgical approaches for the treatment of ankle fractures. A cadaveric study

INTRODUCTION

This study aimed to compare the degree of posterior malleolar exposure, the tension of the flap containing the posteromedial neurovascular bundle (NVB), and the distance between the surgical incision and the NVB using three different posteromedial ankle approaches.

METHODS

Three approaches were compared: medial posteromedial (MePM) modified posteromedial (MoPM) and posteromedial (PM). We measured the minimal tension of the flap containing the NVB that allowed proper exposure. In the second stage, an axial cut was performed, and we measured the degree of posterior malleolar exposure and the distance between the incision and the NVB RESULTS: There were significant differences between the three approaches examined regarding the degree of posterior malleolar exposure and distance from the incision to the NBV,favoring the PM approach (71,00% ± 1.83 and 25.50 mm ± 4.20). The PM approach provided a significantly lower tension to the flap containing the posteromedial NVB (6.18 N ± 1.28) compared to the other two approaches CONCLUSION: The PM approach achieved the highest degree of posterior malleolar exposure, the lowest tension to the posteromedial NVB, and the greatest distance between the incision and the NBV. Thus, we believe it should be considered the approach of choicefor large fractures of the posteromedial aspect of the PM.

Two-staged management of ankle fracture-dislocations with a posterior fragment: computer-tomography-based classification, treatment and its outcome

INTRODUCTION

Trimalleolar fractures are difficult to treat and malreduction can lead to functional impairment. Involvement of the posterior malleolus has a poor predictive value. Current computed-tomography (CT)-based fracture classifications led to an increase in fixation of the posterior malleolus. The aim of this study was to describe the functional outcome after a two-stage stabilisation with direct fixation of the posterior fragment in trimalleolar dislocation fractures.

MATERIALS AND METHODS

In a retrospective study, all patients presenting with a trimalleolar dislocation fracture, an available CT scan, and a two-stage operative stabilisation including the posterior malleolus by a posterior approach were included. All fractures were treated with initial external fixator and delayed definitive stabilisation including fixation of the posterior malleolus. Next to clinical and radiological follow-up, outcome measures (Foot and Ankle Outcome Score (FAOS), Numeric Rating Scale (NRS), Activity of Daily Living (ADL), Hulsmans implant removal score) and complications were analysed.

RESULTS

Between 2008 and 2019, of 320 trimalleolar dislocation fractures, 39 patients were included. Mean follow-up was 49 months (standard deviation (SD) 29.7, range 16-148). Mean age was 60 years (SD 15.3, 17-84) with 69% female patients. The mean FAOS was 93/100 (SD 9.7, 57-100), NRS 2 (interquartile range (IQR) 0-3) and ADL 2 (IQR 1-2). Four patients showed a postoperative infection, three re-operations had to be performed and implants were removed in 24 individuals.

CONCLUSION

A two-stage procedure of trimalleolar dislocation fractures with in-direct reduction and fixation of the posterior tibial fragment through a posterior approach leads to good functional outcome scores with a low rate of complications.

Posteromedial Surgical Approach for Fixation of Haraguchi Type 2B Posterior Malleolar Fracture

SUMMARY

A case of a 26-year-old man with a displaced medial malleolus fracture with extension into the posteromedial aspect of the posterior malleolus is presented. A CT scan of the ankle is obtained demonstrating a Haraguchi type 2B posterior malleolus fracture with a posteromedial and posterolateral fragment. The posteromedial fragment extends into the posterior colliculus of the medial malleolus and has a subchondral impaction fracture. There is also a 1 × 1 cm piece of the articular surface of the posterior malleolus that has flipped 90 degrees and lodged itself between the posterolateral fracture fragment. This video overview and case presentation demonstrates a posteromedial approach with fixation strategy for the posterior malleolus.

Posterolateral approach for posterior malleolus fixation in ankle fractures: functional and radiological outcome based on Bartonicek classification

INTRODUCTION

Posterolateral approach has been advocated for the treatment of ankle fractures involving the posterior malleolus and satisfactory results were demonstrated in several studies. The Bartonicek classification based on 3-dimensional CT scanning was commonly used for treatment recommendation of posterior malleolar fracture (PMF). The aim of this retrospective study was to evaluate the clinical effect of the posterolateral approach for the treatment of PMF and present outcomes of patients with different types of Bartonicek classification.

METHOD

We retrospectively reviewed the clinical outcomes of 72 patients with ankle fractures involving posterior malleolus (PM) from January 2016 to December 2018. Posterior malleolus fractures (PMFs) were all directly reduced and fixed by a posterolateral approach using lag screws and/or buttress plates. AOFAS score and VAS pain score were used as the primary functional outcome measures. The radiographic evaluation included the quality of the reduction and Kellgren-Lawrence (KL) osteoarthritis classification. According to the CT-based Bartonicek classification, all patients were classified into three groups: 42 type II, 18 type III and 12 type IV. Bartonicek type II patients were further divided into subtype IIa 19 cases, subtype IIb 16 cases and subtype IIc 7 cases. The radiological and functional outcomes were analyzed among different types and subtypes of Bartonicek classification.

RESULTS

Sixty-eight patients (94.5%) achieved good or excellent reduction of PMF after surgery. The mean AOFAS score was 81.35 ± 6.15 at 6 months and 90.56 ± 4.98 at the final follow-up, respectively. The VAS score was 6.62 ± 1.03 one week after surgery, and 1.20 ± 0.92 at the final follow-up. Radiological evaluation at the final follow-up showed that primary bone union was achieved in all patients and 65 patients (88.9%) got no (KL grade 0) or just doubtable (KL grade 1) post-traumatic osteoarthritis. AOFAS scores decreased significantly with the severity of Bartonicek classification at 6 month (p < 0.001) and final follow-up (p < 0.05), while there was no statistical difference of VAS pain score among different types of Bartonicek classification. Reduction quality and the presence of osteoarthritis was not correlated to Bartonicek classification either. Besides, AOFAS scores at the final follow-up were statistically different among three subtypes of Bartonicek type II fractures (p < 0.05), and Bartonicek subtype IIa fractures had the highest AOFAS scores as 93 ± 4.99. Presence and severity of osteoarthritis was lower in patients with subtype IIa PMF compared to other subtype groups, this finding was statistically significant (p < 0.05).

CONCLUSION

The posterolateral approach could achieve good clinical outcomes in the treatment of posterior malleolus fracture. Patients with a Bartonicek type II fracture had a better functional outcome measured by the AOFAS score compared to other types. Bartonicek type IIa fractures got a higher AOFAS score and a lower incidence of osteoarthritis at the final follow-up than the other two subtypes. Classification of PMFs according to the Bartonicek classification was reliable.

Use of Distal Tibial Cortical Bone Thickness and FRAX Score for Further Treatment Planning in Patients with Trimalleolar Ankle Fractures

Trimalleolar ankle fractures show a bimodal age distribution, affecting younger men and older women. Postmenopausal women often exhibit low bone mineral density, which contributes to a higher prevalence of osteoporotic-related fractures. The primary goal of this study was to analyse the association of patient characteristics with the cortical bone thickness of the distal tibia (CBTT) in trimalleolar ankle fractures.

METHODS

A total of 193 patients with a trimalleolar ankle fracture treated between 2011 and 2020 were included. Patient registries were reviewed regarding demographics, mechanism, and type of injury. The CBTT was assessed in radiographs and CT images. The FRAX score was calculated to estimate the probability for an osteoporotic fracture. A multivariable regression model was calculated to identify independent variables affecting the cortical bone thickness of the distal tibia.

RESULTS

Patients older than 55 years were 4.22 (95% CI: 2.12; 8.38) times more likely to be female. In the multivariable regression analysis, female sex (β -0.508, 95% CI: -0.739; -0.278, p < 0.001) and a higher age (β -0.009, 95% CI: -0.149; -0.003, p = 0.002) were independent variables associated with a lower CBTT. Patients with a CBTT < 3.5 mm had a higher 10-year probability for a major osteoporotic fracture (12% vs. 7.75%; p = 0.001).

CONCLUSIONS

The assessment of the peripheral bone quality in routine computed tomography demonstrated that higher age and female sex are significantly associated with reduced cortical bone thickness of the distal tibia. Patients with a lower CBTT showed a higher probability for a subsequent osteoporotic fracture. In female patients with reduced distal tibial bone quality and associated risk factors, an osteoporosis assessment should be evaluated.

[Translated article] Posterior malleolar fractures: Indications and surgical approaches

Posterior malleolus fractures are frequent injuries, present in 7-44% of all ankle fractures. The objective of this study is to review the evidence to indicate the fixation of this fracture and to choose the appropriate surgical approach. The classic indications for fixation were fragment size greater than 25-30% of the articular surface and displacement greater than 2mm. However, current evidence suggests that, rather than size, factors such as syndesmotic instability, intra-articular step-off greater than 1-2mm, plafond impaction and the presence of intercalary fragments should be considered. When comparing the different surgical approaches, the literature supports the use of posterior approaches and reserves the recommendation of the traditional approach for exceptional cases. For the treatment of this injury it is essential to know the anatomy of the ankle and to consider all the factors described above, in addition to the presence of concomitant injuries.

Posterior malleolar fractures: Indications and surgical approaches

Posterior malleolus fractures are frequent injuries, present in 7-44% of all ankle fractures. The objective of this study is to review the evidence to indicate the fixation of this fracture and to choose the appropriate surgical approach. The classic indications for fixation were fragment size greater than 25-30% of the articular surface and displacement greater than 2 mm. However, current evidence suggests that, rather than size, factors such as syndesmotic instability, intra-articular step-off greater than 1-2 mm, plafond impaction and the presence of intercalary fragments should be considered. When comparing the different surgical approaches, the literature supports the use of posterior approaches and reserves the recommendation of the traditional approach for exceptional cases. For the treatment of this injury it is essential to know the anatomy of the ankle and to consider all the factors described above, in addition to the presence of concomitant injuries.

Computed tomography-based classifications of posterior malleolar fractures and their inter- and intraobserver reliability: a comparison of the Haraguchi, Bartoníček/Rammelt, and Mason classifications

INTRODUCTION

Complex ankle fractures often include fractures of the posterior malleolus. The most clinically relevant posterior malleolus fracture classifications are computed tomography (CT) based. These classifications aim to enable clear communication and help develop treatment strategies. This study investigates the inter- and intraobserver reliability of the Haraguchi, Bartoníček/Rammelt and Mason posterior malleolar fracture classifications.

MATERIALS AND METHODS

CT scans of 113 patients with a mean age of 56.2 (SD ± 17.8) years and fractures involving the posterior malleolus were analyzed twice by 4 observers with different levels of training. The posterior malleolar fractures were classified according to Haraguchi et al., Bartoníček/Rammelt et al. and Mason et al. The intraobserver and interobserver reliabilities were determined by calculating Cohen's and Fleiss' kappa values.

RESULTS

We found substantial multi-rater interobserver agreement for all three classifications. The Haraguchi classification 0.799 (CI 0.744-0.855) showed the highest agreement, followed by the Bartoníček/Rammelt 0.744 (0.695-0.793) and Mason 0.717 (CI 0.666-0.768) classifications. Subgroup analyses showed substantial to perfect agreement for the Haraguchi and substantial agreement for the Bartoníček/Rammelt and Mason classifications independent of observer expertise. The intraobserver reliability was perfect for three and substantial for one of the observers. However, the classifications have certain pitfalls and do not consider the number of fragments, articular surface impressions, or intercalary fragments.

CONCLUSION

All classifications show substantial, if not perfect inter- and intraobserver reliabilities independent of observer level of expertise.

Intercalary fragments in posterior malleolar fractures: incidence, treatment implications, and distribution within CT-based classification systems

Introduction

Complex ankle fractures frequently include the posterior malleolus (PM). Despite advances in diagnostic and treatment strategies, PM fracture involvement still predisposes to worse outcomes. While not incorporated into the most common PM fracture classifications, the presence of an intercalary fragment (ICF) complicates treatment. This study aims to describe the incidence, morphology, and location of ICFs in PM fractures.

Materials and methods

A total of 135 patients with a mean age of 54.4 (SD ± 18.9) years and PM fractures were analyzed for the presence of an ICF. Patients with an ICF were compared to those without in terms of age, gender, and treatment received. Characteristics of the ICFs in terms of location and size were assessed. Furthermore, the presence of an ICF in relation to the PM fracture classification according to Haraguchi et al., Bartoníček/Rammelt et al., and Mason et al. was investigated.

Results

ICFs presented in 55 (41%) of the 135 patients. Patients with an ICF were younger, and the PM was more often operatively treated when compared to patients without an ICF. A posterolateral approach was used significantly more often in patients with an ICF. Almost all ICFs were found in the posterolateral (58%) and posterocentral (35%) regions. The majority of fragments were found in Bartoníček/Rammelt type 2 fractures, the most common fracture type. Bartoníček/Rammelt type 3 fractures had the highest relative frequency of ICFs.

Conclusion

ICFs are frequently found in PM fractures; however, they are not incorporated into any of the common classifications. They are generally found in younger patients and associated with more complex PM fractures. As they can complicate reduction of the main fragment and may require direct exposure to restore joint congruency, ICFs should be considered in PM fracture classifications. Due to their location, the majority of ICFs are able to be accessed using a posterolateral approach.

Unstable Rotational Ankle Fractures Treated With Anatomic Mortise Repair and Direct Posterior Malleolus Fixation

Introduction: The purpose of this study was to evaluate patient outcomes following a standardized algorithmic approach to ankle mortise stabilization, following rotational fracture, utilizing direct repair of the posterior malleolus in the prone position. Methods: Eighty consecutive patients with unstable rotational ankle fractures that involved the posterior malleolus were analyzed. All underwent direct repair of the posterior malleolus regardless of size through a posterolateral approach. Electronic records were retrospectively reviewed for demographic information, initial injury and operation details, healing status, and complications. Preoperative and postoperative radiographs were obtained to assess the initial injury and healing was determined both by radiographic and clinical progress at follow-up visits. Results: Average posterior malleolus fragment width was 8.1 ± 3.7 mm (range = 2.1-19.9 mm) and percentage of the articular surface was 23.6% (range = 7.1%-56.7%) on the lateral radiograph. Overall, 80/80 (100%) patients healed their ankle fractures by a mean 2.9 ± 1.1 months. Only 1 (1.3%) patient required transsyndesmotic fixation following posterior malleolus repair. Mean range of ankle motion was as follows: dorsiflexion 20° ± 10°, plantarflexion 34° ± 10°, inversion 8° ± 4°, and eversion 7° ± 4°. Seventy-nine patients (98.8%) had an anatomic mortise reduction. Nine patients (11.3%) had a superficial wound complication, 3 patients (3.8%) had dysesthesia in the sural nerve distribution, and 1 patient (1.3%) lost reduction of the medial malleolus. Conclusion: Patients who undergo direct repair of the posterior malleolus in the prone position can expect a high rate of healing with superficial wound breakdown being the biggest problem, which was associated with an ankle fracture dislocation. Posterior malleolus fixation may obviate the need of transsyndesmotic stabilization.Levels of Evidence: Retrospective Level IV.

Complications following surgical treatment of posterior malleolar fractures: an analysis of 300 cases

AIMS

The treatment of ankle fractures and fracture-dislocations involving the posterior malleolus (PM) has undergone considerable changes over the past decade. The aim of our study was to identify risk factors related to the occurrence of complications in surgically treated ankle fractures with PM involvement.

PATIENTS AND METHODS

We retrospectively analyzed 300 patients at a mean age of 57 years with 300 ankle fractures involving the PM treated surgically at our institution over a 12-year period. The following relevant comorbidities were noted: arterial hypertension (43.7%; n = 131), diabetes mellitus (DM) (14.0%; n = 42), thereof insulin-dependent (3.7%; n = 11), peripheral vascular disease (0.7%; n = 2), osteoporosis (12.0%; n = 36), dementia (1.0%; n = 3), and rheumatoid arthritis (2.0%; n = 6). Furthermore, nicotine consumption was recorded in 7.3% (n = 22) and alcohol abuse in 4.0% (n = 12).

RESULTS

Complications occurred in 41 patients (13.7%). A total of 20 (6.7%) revision surgeries had to be performed. Patients with DM (p < 0.001), peripheral vascular disease (p = 0.003) and arterial hypertension (p = 0.001) had a significantly increased risk of delayed wound healing. Alcohol abuse was associated with a significantly higher overall complication rate (OR 3.40; 95% CI 0.97-11.83; p = 0.043), increased rates of wound healing problems (OR 11.32; 95% CI 1.94-65.60; p = 0.001) and malalignment requiring revision (p = 0.033). The presence of an open fracture was associated with an increased rate of infection and wound necrosis requiring revision (OR 14.25; 95% CI 2.39-84.84; p < 0.001). Multivariate analysis identified BMI (p = 0.028), insulin-dependent DM (p = 0.003), and staged fixation (p = 0.043) as independent risk factors for delayed wound healing. Compared to the traditional lateral approach, using the posterolateral approach for fibular fixation did not lead to increased complication rates.

CONCLUSIONS

Significant risk factors for the occurrence of complications following PM fracture treatment were identified. An individually tailored treatment regimen that incorporates all risk factors is important for a good outcome.

How the Direction of Screws Affects the Primary Stability of a Posterior Malleolus Osteosynthesis under Torsional Loading: A Biomechanical Study

Insufficient fixation of a posterior malleolus fracture (PM) can lead to posttraumatic complications such as osteoarthritis and chronic pain. The purpose of this biomechanical study was to test the hypothesis of whether the direction of PM screw fixation has an impact on the primary stability of osteosynthesis of a PM under torsional loading. PM fractures of 7 pairs human cadaveric lower leg specimens were stabilized with posterior to anterior (p.a.) or anterior to posterior (a.p.) screw fixation. Stability of the osteosynthesis was biomechanically tested using cyclic external torsional loading levels, in 2 Nm steps from 2 Nm up to 12 Nm, under constant monitoring with 3D ultrasonic marker (Zebris). The primary stability does not differ between both stabilizations (p = 0.378) with a medium effect size (η2p = 0.065). The movement of the PM tends to be marginally greater for the osteosynthesis with a.p. screws than with p.a. screws. Whether a.p. screws or the alternative p.a. screw fixation is performed does not seem to have an influence on the primary stability of the osteosynthesis of the PM fixation under torsional loading. Although osteosynthesis from posterior seems to be more stable, the biomechanical results in the torsional test show quite equivalent stabilities. If there is no significant dislocation of the PM, a.p. screw fixation could be a minimally invasive but stable surgical strategy.

[Established classification systems of posterior malleolar fractures : A systematic literature review]

BACKGROUND

Posterior malleolar fractures are found in almost 50% of all ankle fractures. The high clinical relevance of these joint fractures is explained by the significantly worse clinical and functional outcome. There is still a lack of unified opinion regarding the classification and treatment of these fractures.

OBJECTIVE

The aim of this article is to provide a systematic literature review of clinical studies that investigated posterior malleolar fractures and classified them using one of the three established classifications according to Haraguchi, Bartonicek/Rammelt, or Mason.

MATERIAL AND METHODS

PubMed was searched without time limits. The systematic literature search was performed according to the current criteria of Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). The methodological quality of the included studies was quantified using the modified Coleman score.

RESULTS

A total of 27 studies with a total of 2220 patients were included in this systematic literature review. Trimalleolar fractures showed a significantly less favorable prognosis than other ankle fractures. The quality of reduction was the most important prognostic factor for the clinical outcome.

CONCLUSION

None of the three classifications examined has become established in the literature. Most of the classifications are weak or should not be used with respect to a derivable treatment algorithm or a prognosis with respect to the outcome. Only the classification according to Bartonicek/Rammelt is suitable to become established in the literature and in clinical practice due to its derivable treatment algorithm.

Evaluation of ankle fracture classification systems in 193 trimalleolar ankle fractures

Purpose

Different classification systems have been developed for ankle fractures. In recent years, the posterior malleolus has gained in importance and led to computed tomography (CT)-based classification systems. The aim of the study was to analyse their reliability, fracture patterns and influence on treatment strategy.

Methods

Patients with a trimalleolar ankle fracture treated between 2011 and 2020 with preoperative radiographs and CT images were included. The blinded images were independently classified by three reviewers according to the AO/OTA, Herscovici, Bartoníček, Mason and Haraguchi classifications. The interobserver reliability was calculated by Fleiss' kappa (κ). CT images were analysed to determine the dimensions of the posterior malleolus fragments. Patient registries were reviewed regarding the treatment data.

Results

A total of 193 patients were included. The AO/OTA classification showed almost perfect inter- and intraobserver reliability (Fleiss’ κ = 0.86, 95% CI 0.82–0.90). Regarding the posterior malleolus, the Bartoníček classification demonstrated the highest reliability (Fleiss’ κ = 0.78, 95% CI 0.73–0.83). The Herscovici classification only reached moderate reliability for medial malleolus fractures (Fleiss' κ = 0.59, 95% CI 0.54–0.65). There was a trend towards direct fixation of the posterior malleolus in the last 3 years of the observation period (OR: 2.49, 95% CI 1.03–5.99).

Conclusion

In trimalleolar ankle fractures, the AO/OTA classification is a reliable system to characterize the type of fracture, but it fails to provide solid information about the posterior malleolus. Nowadays, treatment recommendations for trimalleolar ankle fractures focus on the configuration of the posterior malleolus; therefore, the results of this study advocate the use of the Bartoníček classification as a reliable tool to guide treatment.

Evidence-Based Surgical Treatment Algorithm for Unstable Syndesmotic Injuries

Background: Surgical treatment of unstable syndesmotic injuries is not trivial, and there are no generally accepted treatment guidelines. The most common controversies regarding surgical treatment are related to screw fixation versus dynamic fixation, the use of reduction clamps, open versus closed reduction, and the role of the posterior malleolus and of the anterior inferior tibiofibular ligament (AITFL). Our aim was to draw important conclusions from the pertinent literature concerning surgical treatment of unstable syndesmotic injuries, to transform these conclusions into surgical principles supported by the literature, and finally to fuse these principles into an evidence-based surgical treatment algorithm. Methods: PubMed, Embase, Google Scholar, The Cochrane Database of Systematic Reviews, and the reference lists of systematic reviews of relevant studies dealing with the surgical treatment of unstable syndesmotic injuries were searched independently by two reviewers using specific terms and limits. Surgical principles supported by the literature were fused into an evidence-based surgical treatment algorithm. Results: A total of 171 articles were included for further considerations. Among them, 47 articles concerned syndesmotic screw fixation and 41 flexible dynamic fixations of the syndesmosis. Twenty-five studies compared screw fixation with dynamic fixations, and seven out of these comparisons were randomized controlled trials. Nineteen articles addressed the posterior malleolus, 14 the role of the AITFL, and eight the use of reduction clamps. Anatomic reduction is crucial to prevent posttraumatic osteoarthritis. Therefore, flexible dynamic stabilization techniques should be preferred whenever possible. An unstable AITFL should be repaired and augmented, as it represents an important stabilizer of external rotation of the distal fibula. Conclusions: The current literature provides sufficient arguments for the development of an evidence-based surgical treatment algorithm for unstable syndesmotic injuries.

Current management of trimalleolar ankle fractures

A trimalleolar ankle fracture is considered unstable and treatment is generally performed operatively. Computed tomography is important for the operative planning by providing an elaborated view of the posterior malleolus.

Trimalleolar ankle fractures have a rising incidence in the last decade with up to 40 per 100,000 people per year. With a growing number of elderly patients, trimalleolar ankle injuries will become more relevant in the form of fragility fractures, posing a particular challenge for trauma surgeons.

In patients with osteoporotic trimalleolar ankle fractures and relevant concomitant conditions, further evidence is awaited to specify indications for open reduction and internal fixation or primary transfixation of the ankle joint.

In younger, more demanding patients, arthroscopic-assisted surgery might improve the outcome, but future research is required to identify patients who will benefit from assisted surgical care.

This review considers current scientific findings regarding all three malleoli to understand the complexity of trimalleolar ankle injuries and provide the reader with an overview of treatment strategies and research, as well as future perspectives.

Cite this article: EFORT Open Rev 2021;6:692-703. DOI: 10.1302/2058-5241.6.200138

[Fracture of the posterior malleolus : A paradigm shift]

Ankle fractures with involvement of the posterior malleolus have a poor prognosis. The traditional concept of addressing the posterior fragment as the final step in the surgical reconstruction depending on the fragment size manifest in the lateral X‑ray, does not do justice to the anatomic and biomechanical relevance of the posterior malleolus. Intra-articular step-offs and fragment displacement ≥ 2 mm, impacted intercalary fragments, involvement of the fibular notch and instability of the syndesmosis, represent parameters relevant for the surgical reconstruction and the functional and radiomorphological outcome independent of fragment size. A valid assessment of these parameters can only be achieved via computed tomography (CT) including multiplanar 2D and 3D reconstruction. This is the foundation for the classification of posterior malleolar fractures according to Bartoníček et al., it forms the basis of the preoperative analysis of the fracture components and represents a decision-making tool for the indications for surgery. The individual fracture pattern guides the selection of the suitable approach or a combination of approaches and the surgical strategy. Making use of the posterior approaches enables the surgeon to have a direct view of the fracture components of the posterior malleolus as a precondition for an anatomic reduction. This central surgical step is frequently done as the first measure of the surgical reconstruction of the ankle joint. Furthermore, direct reduction and posterior stabilization is more accurate and stable than indirect reduction from an anterior approach with indirect fixation using lag screws. An additional temporary transfixation of the tibiofibular syndesmosis is often dispensable.