Historic indications for fixation of posterior malleolus fractures- where did they come from and where are we now?

INTRODUCTION: The indications for reduction and fixation of the posterior malleolus component of rotational ankle fractures have been controversial for nearly a century. This study aims to identify the historical basis for surgical intervention and trace trends in management strategies over time. METHODS: In March 2023, a systematic review of full-text, English-language articles providing indications for surgical fixation of the posterior malleolus component of rotational ankle fractures was performed. Articles underwent title and abstract screening before undergoing full-text review. RESULTS: Historical indications for surgical fixation were size-dependent, with fractures comprising 25 % to 33 % of the plafond recommended for internal fixation. Modern studies suggest that nonoperative management of posterior malleolus fractures below this threshold results in residual malreduction of the articular surface, syndesmotic instability, and an increased need for independent fixation of the syndesmosis. CONCLUSIONS: Size-based indications for posterior malleolus fracture fixation are based on Level V evidence from small retrospective case series published nearly one century ago and should be retired. While the size of the posterior malleolus component cannot be ignored, additional factors like fracture morphology and location within the plafond should guide modern surgical indications. Contemporary studies indicate that reduction and fixation of small posterior malleolus fractures (comprising less than 25 % of the articular surface) are associated with improved articular reductions, tibiotalar contact pressures, syndesmotic stability with decreased need for independent fixation of the syndesmosis, and superior postoperative outcomes.

The Effect of Prone and Supine Limb Positioning on the Radiographic Evaluation of Posterolateral Plate Fixation of the Posterior Malleolus.

Aim: To facilitate the posterolateral approach to the posterior malleolus patients are often positioned prone initially, then turned supine to complete fixation at the medial malleolus. We sought to define observed differences in the radiographic appearance of implants relative to the joint line, in prone and supine positions. Methods: A 3.5 mm tubular plate and a 3.5 mm posterior distal tibial periarticular plate were applied sequentially to 3 individual cadaveric legs, via a posterolateral approach. The tubular plate was positioned to simulate buttress fixation and the posterolateral plate placed more distally. Each limb was secured on a custom jig and radiographs were taken on a mobile c-arm fluoroscopy machine with a calibration ball. A series of prone AP, supine PA and mortise radiographs were taken. Prone radiographs were also taken in different degrees of caudal tilt to simulate knee flexion which occurs in practice, during intraoperative positioning. Plate tip-joint line distances were measured and Mann-Whitney U tests performed. Results: There was no statistically significant difference in plate tip-joint line distance when comparing equivalent prone and supine views (PA/AP or mortise). However, significant differences in apparent implant position were noted with alterations in caudal tilt. When taking a prone image, when the knee is flexed to 20 degrees, the plate tip will appear 6.5-8.5 mm more proximal than in the equivalent supine image where the knee is extended and the fluoroscopy beam is orthogonal to the anatomic axis of the tibia. Conclusion: Observed differences in radiographic appearance of metalwork in the prone and supine position are most likely due to knee flexion and the resulting variation in the angle of the fluoroscopy beam, rather than projectional differences between supine and prone views. Surgeons should be alert to this when analysing intraoperative images.

Computed tomography changes diagnosis, management and surgical planning of ankle fractures.

PURPOSE: To demonstrate how the use of adjunctive Computed Tomography (CT) can modify diagnosis, treatment options, and operative planning of ankle fractures in comparison with conventional radiographs (CR) in isolation. MATERIALS AND METHODS: A total of 53 patients diagnosed with an ankle fracture between 2011 and 2016, were assessed with CT and CR. Evaluations of the fractures using CR in isolation and CR combined with CT were compared using different readers. Fractures were assessed in terms of type, displacement, size, associated injuries, treatment, patient position and surgical planning. RESULTS: The medial malleolus fractures characteristics (posteromedial fragment and anterior colliculus), the presence of posterior malleolus fracture and its characteristics (displacement, size, posteromedial or posterolateral segment) (ps < 0.042), syndesmosis injury (p < 0.001), and the absence of deltoid ligament lesion (p < 0.001), were more evident with the combination of CT and radiographs. There was an increase in operative indication (p = 0.007), prone positioning (p = 0.002), posterior malleolus surgical treatment (p < 0.001), posterolateral approach for the lateral malleolus (p = 0.003), and syndesmosis fixation (p = 0.020) with the association of CT and CR, among all groups of expertise, with a high interobserver reliability (> 0.75). CONCLUSIONS: The CR may fail to demonstrate subtle lesions, such as posterior malleolus fractures and syndesmotic injuries. The CT evaluation increases the diagnostic precision and improves the quality of information the surgeon receives, what might positively affect patient care. LEVEL OF EVIDENCE III: Retrospective Comparative Study.

Ten year outcomes after non-fixation of the smaller posterior malleolar fragment: A retrospective cohort study.

INTRODUCTION: Treatment of posterior malleolar (PM) ankle fractures remains controversial. Despite increasing recommendation for small PM fragment fixation, high quality evidence demonstrating improved clinical outcomes over the unfixated PM is limited. We describe the long term clinical and radiographical outcomes in younger adult patients with PM ankle fractures managed without PM fragment fixation. MATERIAL AND METHODS: A retrospective cohort study was performed on PM ankle fracture patients aged 18-55 years old admitted under our orthopaedic unit between 1st of April 2009 and 31st of October 2013. Inclusion criteria were ASA 1 and 2, independent mobility pre-trauma, no pre-existing ankle pathologies, with satisfactory bimalleolar and syndesmotic stabilisation. Open fractures, talar fractures, calcaneal fractures, pilon fractures, subsequent re-injury and major complications were excluded. All PM fragments were unfixated. Clinical outcomes were evaluated using visual analogue scale (VAS) for pain, Foot and Ankle Ability Measure (FAAM) with activities of daily living (ADL) and sports subscale for function, and patient satisfaction ratings. Osteoarthritis was assessed using modified Kellgren-Lawrence scale on follow-up weightbearing ankle radiographs. RESULTS: Sixty-one participants were included. Mean follow-up was 10.26 years. Average PM size was 16.2 ± 7.39%. All participants were evaluated for clinical outcomes. Mean score of FAAM-ADL was 95.5 ± 7.13, FAAM-Sports 86.4 ± 15.5, patient satisfaction 86.2 ± 14.4% and pain score 1.13 ± 1.65. Radiographical outcomes were evaluated in 52 participants, showing no-to-minimal osteoarthritis in 36/52 (69%), mild osteoarthritis in 14/52 (27%) and moderate osteoarthritis in 2/52 (4%). Pain and functional scores were independent of PM fragment size, post-reduction step-off, dislocation, malleoli fractured or syndesmotic injury. PM step-off more than 1 mm and traumatic dislocation/subluxation were associated with worse radiographical osteoarthritis. CONCLUSION: After controlling for confounders, the unfixated smaller posterior malleolus fragment at 10-year follow-up demonstrated largely satisfactory clinical outcomes with some radiographical progression of osteoarthritis. LEVEL OF EVIDENCE: Level III - Retrospective cohort study.

Long-term Clinical and Radiographic Outcomes Following Surgical Treatment for Ankle Fracture-Dislocations: Do poor radiographic outcomes always matter?

Background Ankle fractures constitute 10% of all traumatic fractures in clinical practice. Concurrent tibiotalar dislocations form 21-36% of all ankle fractures. Although mechanism of injury is similar to non-dislocated ankle fractures, fracture-dislocations cause more extensive bone and soft tissue damage. Treatment is a challenge for orthopedic surgeons due to concomitant pathologies. It is associated with malreduction, chronic pain and most importantly, posttraumatic osteoarthritis. We aimed to investigate the relationship between ankle osteoarthritis radiographic stage and clinical outcomes. Methods 27 patients (17 female, 10 male) were included in the study. Records and data were retrospectively analyzed. Clinical status at the final follow-up was evaluated by a single orthopedic surgeon. Range of motion (ROM), American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score, visual analogue scale (VAS) were the clinical parameters that were assessed. Radiological assessment was made by standard anteroposterior [AP], lateral, and mortise views. Pre-operative osseo-ligamentous injury pattern, presence of posterior malleolar fracture, syndesmosis injury and post-operative ankle osteoarthritis were investigated. Results For 27 patients that were evaluated, at the final follow-up, mean AOFAS was 85 ± 8.12, and mean VAS during daily activities was 1.52 ± 0.70. Mean ankle dorsiflexion and plantar flexion were significantly lower on the affected sides (14.07 ± 7.97° and 36.30 ± 6.59°) than on the unaffected sides (28.15 ± 2.82° and 46.30 ± 2.97°), respectively (p < 0.001). No significant difference for inversion and eversion was observed. Twenty-four patients demonstrated radiographic signs of ankle osteoarthritis, and three remained without evidence of osteoarthritis. No significant difference was found among Takakura's stages in any of the variables. Conclusion The results illustrated that although post-traumatic osteoarthritis rate was high for ankle fracture-dislocation patients, surgical treatment achieved excellent functional results. Even if advanced stages of ankle arthritis according to Takakura's classification developed, patients had satisfactory clinical and functional results.

Computed Tomography Scans and Fixation Rates for Trimalleolar Ankle Fractures Over 10 Years at a Level 1 Trauma Center.

Background: The posterior malleolus component of the trimalleolar ankle fracture has posed a controversial topic for diagnostic imaging and surgical management. Preoperative computed tomography (CT) scans are used to better appreciate fracture morphology and may affect management techniques. No prior study has investigated the trend in preoperative CT scan use and the rates of posterior and syndesmotic fixation for trimalleolar injuries. Methods: This retrospective cohort study evaluated the use of preoperative CT scans and the rates of posterior and syndesmotic fixation for trimalleolar ankle fractures over a 10-year period at an adult level 1 trauma center. Patients surgically managed for ankle fractures with OTA/AO classifications of 44B3, 44C3.3, 44C1.3, 44C2.3, and 44A3 were identified and included using Current Procedural Terminology codes and a prospectively collected fracture registry. Demographic information, comorbidities, fixation methods, and use of preoperative CT scan were recorded. Comparative analyses were performed to assess for yearly differences in demographic characteristics along with changes in trends of preoperative CT scans and posterior and syndesmotic fixation. Results: A total of 1191 patients were included in the analyses. OTA/AO 44B3.2 fractures were the most common injuries (yearly range of 59.4%-80.1%). The rate of posterior fixation did not significantly increase during the study interval (1.4% growth per year [95% CI -0.27, 3.07]). However, the rate of preoperative CT scan use significantly increased by 2.76% (95% CI 1.99, 3.52) per year and the rate of syndesmotic fixation increased by 2.58% (95% CI 1.17, 3.99) per year. Fixation methods for both the syndesmosis and posterior malleolus changed during the study timeline. Conclusion: Despite a relatively stable rate of posterior fixation, the frequency of preoperative CT scans and use of syndesmotic fixation increased significantly over a 10-year study period. Level of Evidence: Level IV, descriptive pilot study.

The reliability of posterior malleolar ankle fracture assessment: a unique perspective.

AIM: This study aims to elucidate the pathology of PMFs in the South African population, establish correlations between fracture patterns and international classification guidelines and evaluate the interobserver reliability of current classifications. METHODS: A retrospective review was conducted in a multicentre analysis over a one-year period from January 2019 to December 2019 at our institution. Computer tomography scans for foot and ankle injuries were reviewed, and posterior malleolus fractures were included. Pathoanatomical data was collected and analysed according to known classification systems and subsequent treatment modalities evaluated. A panel of observers individually reviewed radiographic data to determine interobserver reliability. RESULTS: A total of 71 patients were included with a mean age of 41 ± 13.4 years (range 18-78) and a female predominant population (69%). A greater proportion of injuries were high energy (23.9%), with significant fragment comminution (53.5%), and half (52.1%) of all injuries were subluxated/dislocated at presentation. A total of 93% of injuries were managed operatively, despite theatre access limitations resulting in significant delays to fixation (19.1 days). Despite good pathoanatomical agreement with most international classifications, interobserver reliability was poor (Krippendorff α-coefficient < 0.667). Inconsistent treatment patterns in operative and non-operative strategies are reported. CONCLUSION: A unique patient population of younger, female individuals incurred posterior malleolar fractures due to higher energy mechanisms of injury. Whilst injury patterns were mostly comparable, significant interobserver variability was noted. Resource limitations, diagnostic challenges, poorly defined and inconsistent treatment strategies, inevitably impact outcomes within the South African population. LEVEL OF EVIDENCE: Level III.

Morphology of Fibular Incisura is a Deciding Factor Between Posterior Malleolus Avulsion Fracture or Syndesmotic Ligament Injury in Ankle Fractures.

The bone anatomy of tibiofibular syndesmosis has been a topic of interest. Fibular incisura morphology has been analyzed on cadaver specimens, plain radiographs, or CT images. The aim of this study is to examine the effects of fibula incisura features and fibula morphology in ankle injuries, especially involving posterior malleolus and posteroinferior tibiofibular ligament injuries. From 2017 through 2022, A total of 59 patients with isolated lateral malleolar fracture, Mason-Malloy type 1 posterior malleolar fracture, syndesmosis injury in those without posterior malleolar fracture, supination external rotation type 3 injuries according to Lauge-Hansen classification, and preoperative bilateral ankle computed tomography images were included in the study. Fibula morphologies and syndesmosis measurements were made from preoperative computed tomography images using axial CT images from 1 cm proximal to the tibial plafond. The diagnosis of posterior malleolar fractures was made using the CT classification system of Mason and Malloy, and the diagnosis of syndesmosis injury was made with a cotton test during surgery. Age, gender, fractured side, incisura type, incisor depth, width, anterior and posterior facet lengths, incisor version (antevert-retrovert), the angle between the anterior and posterior facets, and fibula type were recorded. There was a statistically significant difference between the groups in posterior facet length and incisura width. Morphological features of fibular incisura may be the determinant of PITFL injury or PMA injury in fibular fractures caused by an external rotation mechanism.

Injury to the posterior malleolus in Maisonneuve fractures.

PURPOSE: The aim of this study was to describe the incidence and a complex pathoanatomy of posterior malleolus fractures in a Maisonneuve fracture. METHODS: The study included 100 prospectively collected patients with a complete clinical and radiological documentation of an ankle fracture or fracture-dislocation including a fracture of the proximal quarter of the fibula. RESULTS: A posterior malleolus fracture was identified in 74 patients, and in 27% of these cases it carried more than one quarter of the fibular notch. Displacement of the posterior fragment by more than 2 mm was shown by scans in 72% of cases. Small intercalary fragments were identified in 43% of cases. Fractures of the Tillaux-Chaput tubercle were identified in 20 patients. CONCLUSION: Our study has proved a high rate of posterior malleolus fractures associated with a Maisonneuve fracture, and documented their considerable variability in terms of involvement of the fibular notch, tibiotalar contact area, direction of displacement and frequency of intercalary fragments. Of no less importance is a combination of Tillaux-Chaput fractures with a Maisonneuve fracture.

Biomechanical insights into ankle instability: a finite element analysis of posterior malleolus fractures.

BACKGROUND: Posterior malleolus fractures are known to be associated with ankle instability. The complexities involved in obtaining precise laboratory-based spatial pressure measurements of the ankle highlight the significance of exploring the biomechanical implications of these fractures. METHODS: Finite element analysis was utilized to examine the stress distribution across the contact surface of the ankle joint, both in its natural state and under varied sagittal fracture line angles. The study aimed to identify stress concentration zones and understand the influence of sagittal angles on stress distribution. RESULTS: Three distinct stress concentration zones were identified on the ankle's contact surface: the anterolateral tibia, the anteromedial tibia, and the fracture line. The most significant stress was observed at the fracture line when a fracture occurs. Stress at the fracture line notably spikes as the sagittal angle decreases, which can potentially compromise ankle stability. Larger sagittal angles exhibited only minor stress variations at the contact surface's three vertices. It was inferred that sagittal angles below 60° might pose risks to ankle stability. CONCLUSIONS: The research underscores the potential implications of fractures on the stress profile of the ankle joint, emphasizing the role of the contact surface in ensuring stability. The identification of three zones of stress concentration and the influence of sagittal angles on stress distribution offers a valuable reference for therapeutic decision-making. Further, the study reinforces the importance of evaluating sagittal fracture angles, suggesting that angles below 60° may compromise ankle stability.

Biomechanical Efficacy of Three Methods for the Fixation of Posterior Malleolar Fractures: A Three-Dimensional Finite Element Study.

Introduction: We investigated the biomechanical behaviour of different fixations of the tibial posterior malleolus (TPM), simulating distinct situations of involvement of the tibiotalar articular surface (TTAS) through a finite element model (FEM). Material and methods: A 3D computer-aided design model of the left ankle was obtained. The materials used were divided according to their characteristics into ductile and non-ductile, and all materials were assumed to be linear elastic, isotropic, and homogenous. Three different fracture lines of the TPM were defined, with sagittal angles of 10°, 25°, and 45°. For biomechanical comparison, different constructions using a trans-syndesmotic screw (TSS) only (Group T), a one-third tubular plate only with (Group PT) and without (Group PS) a TSS, and a locked compression plate with (Group LCPT) and without (Group LCPS) a TSS were tested. FEM was used to simulate the boundary conditions of vertical loading. Load application regions were selected in the direction of the 700 N Z-axis, 90% on the tibia and 10% on the fibula. Data on the displacement and stress in the FEM were collected, including the total principal maximum (MaxT) and total principal minimum (MinT) for non-ductile materials, total displacement (desT), localized displacement at the fragment (desL), localized displacement at syndesmosis (desS), and Von Mises equivalent stress for ductile materials. The data were analysed using ANOVA and multiple comparison LSD tests were used. Results: For TPM fractures with sagittal angles 10° and 25°, desL in the PT and LCP groups was significantly lower, as well as Von Mises stress in Group LCPT in 10°, and PT and LCPT groups in 25°. For TPM fractures with a sagittal angle of 45°, desL in the LCP group and Von Mises stress in Group LCPS and LCPT were significantly lower. We found that any TPM fracture may indicate instability of the distal tibiofibular syndesmosis, even when the fragment is small. Conclusion: Our study showed that in fragments involving 10% of the TTAS, the use of a TSS is sufficient, but when the involvement is greater than 25% of the TTAS, either a non-locked or locked plate must be used to buttress the TPM. In posterior fragments affecting 45% or more of the TTAS, the use of a locking plate is recommended.

Ankle fractures malreduction rate and its causes in two Brazilian tertiary training hospitals.

INTRODUCTION: Ankle fractures are one of the most frequent injuries managed by any trauma surgeon. Literature has shown that adequate reduction is of utmost importance to achieve satisfactory functional outcomes. However, malreduction rates remain high worldwide. The objective of the present study is to evaluate the quality of ankle fracture reduction in two major trauma centers in a large Brazilian city and to analyze the factors associated with malreduction METHODS: Epidemiologic data of 382 patients (189 men; 193 women) aged between 7 and 87 years who underwent osteosynthesis of the ankle in two trauma centers in a large Brazilian city. Electronic clinical records, preoperative and immediate postoperative radiographs in anteroposterior (AP), lateral and mortise views were evaluated. Pettrone's criteria were used to evaluate the quality of ankle fractures reduction. All radiographs were independently evaluated by two foot and ankle senior surgeons RESULTS: Overall, malreduction rate was 22.2%. Forty-seven (55.2%) fractures classified as malreduced had medial malleolar displacement The results showed three factors that significantly affected the quality of reduction (p<0.05), patients over 60 years, open fractures and fracture-dislocations. Patients aged over 60 years were twice more likely to have poor reduction of ankle fractures than younger ones. The risk of poor fracture reduction among those individuals with open fractures is 2.15 times greater than among patients with closed injuries. Fracture-dislocation imposed a 2.7 higher risk for malreduction DISCUSSION: We found a malreduction rate below most series previously published. Further results agree with the literature. Elderly people aged over 60 years, fracture dislocations and open fractures are associated with worse results, influencing the quality of the reduction, clinical outcomes, and the development of post-traumatic arthrosis CONCLUSION: Ankle fractures malreduction are associated with higher age, open fractures, and fracture-dislocations.

Safety of the modified posteromedial approach in complex ankle fractures: Comparative analysis versus posterolateral access.

INTRODUCTION: The aim of the study was to evaluate the safety of the modified posteromedial approach (MfPM) in the surgical management of complex ankle fractures in terms of local complications. METHODS: Retrospective multicenter review of a series of malleolar fractures surgically treated by posterior ankle approaches between 2016 and 2022. Two approaches were used. In the MfPM group patients were placed in a prone position and the incision was made 1 cm medially to the Achilles tendon. In the posterolateral access (PL) group patients were placed in a prone or lateral decubitus position and the incision was made between the lateral malleolus and the Achilles tendon. Complications evaluated were divided into wound complications, infections, neuritis, vascular alterations and others. RESULTS: 81 ankle fractures with a posterior malleolar fragment treated by open reduction and internal fixation were identified. 20 cases were approached through the MfPM approach and 61 through the PL access. The mean follow up was 18.60 months (range 4-78 months). In the MfPM group the local complication rate was 10% (2/10 patients), both corresponding to minor wound problems which required no surgical intervention. No infection or other neural or vascular complications were found. In the PL group a complication rate of 8,19% (5/61 patients) was found, all of them corresponding to minor wound problems which required no surgical intervention. No infection or other neural or vascular complications were found. There were no significant differences between the two approaches regarding postoperative local complications (z score 0.249 - P: 0.803). CONCLUSION: The MfPM approach is safe and may become as readily used as the PL due to the low incidence of postoperative local complications, especially in fractures with a large fragment and posteromedial extension in which greater access to the posterior pilon can facilitate instrumentation for anatomic reduction and fixation.

Early history of posterior malleolus fractures in ankle fractures.

INTRODUCTION: No comprehensive treatise on the early history of fractures of posterior malleolus (PM) has yet been published, and many substantial discoveries have fallen into oblivion-particularly if not having been published in English originally. MATERIALS AND METHODS: Literature search was performed in original publications and historical sources. RESULTS: Early history of PM fractures from their first description up to the beginnings of their operative treatment may be divided into three basic periods, covering the era between 1828 and 1940. In the pre-radiological period (1828-1895), description of PM injuries was based merely on the autopsy findings in deceased patients. The first mentions of this injury were published by the British authors. In the radiologic period (1899-1916), the x-ray examination started a revolution also in diagnostics of ankle fractures, with the first radiographs performed as early as in 1899. Radiographic examination had subsequently become an integral part of the diagnostics of these injuries and initiated a number of significant studies of PM fractures. The first detailed mention of a PM injury may be found in the French and German literature. The period of early operative treatment (1918-1940), i.e., open reduction and internal fixation of PM, was started by the younger post-WWI generation, primarily the French surgeons, represented by Gaston Picot. His operative technique and the first six cases treated operatively between 1918 and 1921 were described in 1921 by Edouard Huc. Picot himself published his technique in great detail in 1923. CONCLUSION: The early history of diagnostics and treatment of PM fractures witnesses the remarkable body of knowledge gathered about that topic by numerous visionary surgeons predominantly French and German surgeons immediately before and after World War I. They substantially contributed to the radiological examination and operative treatment of this injury.

Enhancing Consistency in Posterior Malleolus Fracture Classification: A Comprehensive Interobserver Reliability Study With 20 Raters Using the Mason & Molloy Classification.

INTRODUCTION: Over the past decade, there has been a growing interest in the identification and treatment of posterior malleolus fragments, driven by a better understanding of their significance. The Mason & Molloy (M&M) classification system has emerged as a valuable tool for systematically categorizing these fractures and assisting clinicians in formulating treatment. We aim to assess the interobserver reliability of the M&M classification for posterior malleolus fracture by using 20 raters. METHODOLOGY: The study was conducted at a major foot and ankle referral center in Wythenshawe, Manchester, UK. Thirty-eight Computed Tomography (CT) scans were evaluated by 20 independent raters: 15 general orthopedic and trauma surgeons plus five foot and ankle surgeons. Each rater classified the posterior malleolus fracture according to M&M classification into type 1, 2A, 2B, 3, or not classifiable. Statistical analysis was done with the R software package and SPSS (v26; IBM Corp., Armonk, NY). Fleiss kappa (κ) coefficient with a 95% confidence interval (CI) was applied. RESULTS: The interobserver agreement was moderate with a global κ value of 0.531 (95% CI: 0.518, 0.544). There were good agreements for identifying type 3 M&M (κ=0.785) and those that are not applicable for M&M classification (κ=0.785). There was a strong correlation between all raters in using M&M classification (Tb=0.53-0.59) except for Rater 12. CONCLUSION: M&M classification remains a valuable tool to guide the management of patients with these subsets of ankle fractures.

Reduction of Posterior Malleolus Fractures With Open Fixation Compared to Percutaneous Treatment.

Background: Operative decision making between approaches to posterior malleolus reduction remains a challenge. The purpose of this study is to compare the quality of reduction between percutaneous and open reduction of posterior malleolus fractures and to identify factors associated with malreduction. Methods: Operatively managed ankle fractures that included posterior malleolus fixation were reviewed. Fracture characteristics were determined on preoperative CT scans. Initial postoperative radiographs were used to measure reduction of the posterior malleolus articular surface and graded as satisfactory (<2 mm step-off) or malreduced (≥2 mm step-off). Final postoperative PROMIS scores and 1-year complications were compared between percutaneous and open cohorts. A multivariate stepwise regression model was used to evaluate predictors for malreduction. Results: A total of 120 patients were included. Open reduction was performed in 91 (75.8%) compared with 29 (24.2%) who underwent percutaneous reduction. Malreduction (≥2-mm articular step-off) occurred in 11.7% of patients. Malreduction rates were significantly higher with percutaneous fixation than open fixation (24.1% vs 7.7%, P = .02). Multiple fragments and those with ≥5 mm of displacement demonstrated higher malreduction rates with percutaneous fixation (P < .05 for both), whereas single fragments and those with <5 mm of displacement experienced similar malreduction rates with percutaneous or open fixation. Initial displacement ≥5 mm (relative risk [RR] = 3.8, 95% CI = 1.2-11.5, P = .02) and percutaneous treatment (RR = 4.1, 95% CI = 1.6-10.5, P < .01) were identified as independent risk factors for malreduction. There were no significant differences in 1-year complication rates or final PROMIS scores between groups. Conclusion: Open reduction of the posterior malleolus may lead to improved fracture reduction compared to percutaneous reduction without significant increase in complications. Open fixation improves reduction among fractures with multiple fragments or ≥5 mm of displacement, whereas fractures with a single fragment or <5 mm of displacement achieve similar reductions regardless of approach. Initial displacement ≥5 mm and percutaneous reduction are independent risk factors for malreduction. Level of evidence: Level III, therapeutic.

Quantitative Evaluation of the Influence of Posterior Malleolus Fracture and Fixation on the Rotational Stability of the Ankle.

Background: This study aimed to analyze quantitative correlation between the posterior malleolus fracture and fixation and the rotational stability of the ankle and to explore supplementary surgical indications for posterior malleolus fracture. Methods: Twenty fresh frozen cadaver specimens were selected and dissected. Based on the tibial insertion of the ligament complex, the model for the supination external rotation stage 3 ankle fracture with a posterior malleolar fragment and syndesmosis diastasis was created. The area threshold of the posterior tibial insertion of posterior malleolus fracture was biomechanically assessed and the difference of the antirotating ability stiffness of the ankle between simple posterior malleolus fixation and simple syndesmotic fixation was analyzed statistically. Results: The tibial insertion of posterior inferior tibiofibular ligament and inferior transverse tibiofibular ligament complex was relatively broad, and its width decreased as the distance from the joint line increased. Biomechanical analysis showed that: the threshold of posterior area of posterior malleolus fracture was 1/4S; posterior malleolus fixation provided better rotational stability than syndesmotic fixation (P < 0.01). Conclusion: The surgical indications for posterior malleolus fracture should consider simultaneously the restoration of the axial and rotational stability of the ankle. Simple posterior malleolus fracture fixation is recommended when the syndesmosis is unstable and the area ratio of posterior tibial insertion of posterior malleolus fracture is greater than or equal to 1/4. Syndesmotic fixation is proposed to restore and maintain the rotational stability of the ankle when the syndesmosis is unstable and the area ratio is less than 1/4. Regardless of the area ratio, the surgical indication only depends on the impact of the posterior malleolus fracture on the axial stability of tibiotalar joint, the involved articular surface area, and the displacement degree of posterior malleolus fragment, when the syndesmosis is stable.

The arterial risk posed by the posterolateral approach: An anatomical cadaveric study of the fibular artery and its variability.

The posterior malleolus of the tibia is commonly accessed surgically through the posterolateral approach. This approach gives good access to the fibula and lateral aspect of the posterior tibia, however; there is little known on the vascular risks with this approach. The aim of this study was to assess and describe the anatomy of the fibular artery and its branches at the ankle region and relate it to the surgical access of the posterior malleolus. Eleven cadaveric foot and ankle specimens were dissected in layers, preserving the fibular artery, anterior tibial artery (ATA), and posterior tibial artery (PTA). Five distinct variations were found in the fibular artery: variable terminal branching with a hyperplastic fibular artery; a superficially located fibular artery; variation in the level and number of anastomoses; variation in the muscular branches; and a variable anterior perforating branch. The mean proximal distance from a horizontal line drawn through the medial protuberance of the medial malleolus of the tibia (horizontal line reference point-HLRP) to the posterior communicating branch of the fibular artery was 37.93 mm (range 19.03-85.43 mm). The mean proximal distance between HLRP and the anterior perforating branch of the fibular artery was 44.23 mm (range 35.44-62.32 mm). In 10 specimens, the fibular artery was immobile distal to its anterior perforating branch. The posterolateral approach specifically puts the fibular artery at risk and knowledge of its anatomy and variability is important when undertaking this approach. Understanding the common variations within the ankle's arterial anatomy can help surgeons protect these vessels from damage during the surgical approach.

Dance Around the Fibula with a Twisted Plate: A Technical Note.

Nowadays, there is a better understanding of the role of the posterior malleolar fragment in trimalleolar ankle fractures. Not fragment size, but rather fragment morphology should guide the management of the posterior malleolar fracture (PMF). Anatomical reduction and fixation of the PMF is important, as an intra-articular step-off will eventually lead to osteoarthritis. Incongruency of the incisura fibularis tibia is associated with fibular dislocation, syndesmotic insufficiency, and poor functional outcomes. Open reduction and internal fixation through a posterior approach leads to ankle joint mobility restriction (i.e., dorsal flexion deficiency) due to arthrofibrosis of the ankle joint, fibrous adhesions and secondary shortening of the flexor muscles. In this technical note, we describe a surgical technique to fixate unstable ankle fractures with a combined PMF and a high supra-syndesmotic fibular fracture through two small surgical windows using a twisted one-third tubular plate. By reducing the size of the posterolateral window, fibrous adhesions and secondary flexor muscle shortening are diminished, favoring ankle joint mobility.

Analysis of the epidemiological characteristics of posterior malleolus fracture in adults.

BACKGROUND: This study explores the latest epidemiological characteristics of posterior malleolus fracture and compares the epidemiological differences of posterior malleolus fracture in different periods, regions, and adult age groups. METHODS: Clinical information of inpatients with posterior malleolus fracture in Shanghai Tongji Hospital and Karamay Central Hospital from January 2014 to February 2022 was reviewed and collected. The imaging data of patients were acquired using the Picture Archiving and Communication Systems. A statistical analysis was performed as to gender, current age, year of admission, injury mechanism, fracture type, and posterior malleolus fracture classification. Moreover, a comparative analysis was conducted on the injury mechanisms and morphological differences of posterior malleolus fracture at different periods, regions, and age groups. RESULTS: A total of 472 patients (210 patients from Shanghai Tongji Hospital and 262 patients from Karamay Central Hospital) with posterior malleolus fracture and an average age of 48.7 ± 15.6 were included in this study. The peak of posterior malleolus fracture occurs in the age group of 50-59. The injury mechanisms mainly involve low-energy fall and sprain (411 cases, 87.1%), followed by traffic accidents (52 cases, 11.0%), and fall injury from height (9 cases, 1.9%). With aging, the number of fall and sprain cases increases and reaches the peak at the age of 50-59, followed by progressive decline. Traffic accidents presents a relatively flat small peak in the age group of 40-59. The number of cases according to different fracture types shows the following ascending order: trimalleolar fracture-supination external rotation (335 cases, 71.0%) > bimalleolar fracture (60 cases, 12.7%) > trimalleolar fracture-pronation extorsion (43 cases, 9.1%) > posterior malleolus + tibial shaft fracture (19 cases, 4.0%) > simple posterior malleolus fracture (15 cases, 3.2%). The numbers of cases corresponding to the Haraguchi I Type, II Type, and III Type of posterior malleolus fractures were 369 (78.2%), 49 (10.4%), and 54 (11.4%), respectively. The Tongji IIA Type represented the highest number of cases (249 cases, 52.8%), followed by the IIB Type (120 cases, 25.4%), I Type (54 cases, 11.4%), IIIB Type (36 cases, 7.6%), and IIIA type (13 cases, 2.8%). The trimalleolar fracture-supination external rotation, Haraguchi I Type and Tongji IIA Type of posterior malleolus fractures all presented an obvious peak of incidence in the age group of 50-59. However, no obvious statistical difference was observed in the injury mechanism, Haraguchi classification, and Tongji classification of posterior malleolus fractures among different years and regions in recent years (P > 0.05). CONCLUSIONS: The injury mechanism of posterior malleolus fracture mainly involves low-energy fall and sprain cases. The trimalleolar fracture-supination external rotation, Haraguchi I type and Tongji IIA type of posterior malleolus fracture are predilection fracture types, and all present an obvious incidence peak in the age group of 50-59. Elderly patients have high risks of falling and their bones are more fragile, conditions which are potential risk factors of posterior malleolus fracture. Early positive control has important significance. This study provides references for relevant basic and clinical studies of posterior malleolus fracture.