Aims. Paediatric triplane fractures and adult trimalleolar ankle fractures both arise from a supination external rotation injury. By relating the experience of adult to paediatric fractures, clarification has been sought on the sequence of injury, ligament involvement, and fracture pattern of triplane fractures. This study explores the similarities between triplane and trimalleolar fractures for each stage of the Lauge-Hansen classification, with the aim of aiding reduction and fixation techniques. Methods. Imaging data of 83 paediatric patients with triplane fractures and 100 adult patients with trimalleolar fractures were collected, and their fracture morphology was compared using fracture maps. Visual fracture maps were assessed, classified, and compared with each other, to establish the progression of injury according to the Lauge-Hansen classification. Results. Four stages of injury in triplane fractures, resembling the adult supination external rotation Lauge-Hansen stages, were observed. Stage I consists of rupture of the anterior syndesmosis or small avulsion of the anterolateral tibia in trimalleolar fractures, and the avulsion of a larger Tillaux fragment in triplanes. Stage II is defined as oblique fracturing of the fibula at the level of the syndesmosis, present in all trimalleolar fractures and in 30% (25/83) of triplane fractures. Stage III is the fracturing of the posterior malleolus. In trimalleolar fractures, the different Haraguchi types can be discerned. In triplane fractures, the delineation of the posterior fragment has a wave-like shape, which is part of the characteristic Y-pattern of triplane fractures, originating from the Tillaux fragment. Stage IV represents a fracture of the medial malleolus, which is highly variable in both the trimalleolar and triplane fractures. Conclusion. The paediatric triplane and adult trimalleolar fractures share common features according to the Lauge-Hansen classification. This highlights that the adolescent injury arises from a combination of ligament traction and a growth plate in the process of closing. With this knowledge, a specific sequence of reduction and optimal screw positions are recommended. Cite this article: Bone Joint J 2024;106-B(9):1008–1014

It has previously been suggested that among unstable ankle fractures, the presence of a malleolar fracture is associated with a worse outcome than a corresponding ligamentous injury. However, previous studies have included heterogeneous groups of injury. The purpose of this study was to determine whether any specific pattern of bony and/or ligamentous injury among a series of supination-external rotation type IV (SER IV) ankle fractures treated with anatomical fixation was associated with a worse outcome.

We analysed a prospective cohort of 108 SER IV ankle fractures with a follow-up of one year. Pre-operative radiographs and MRIs were undertaken to characterise precisely the pattern of injury. Operative treatment included fixation of all malleolar fractures. Post-operative CT was used to assess reduction. The primary and secondary outcome measures were the Foot and Ankle Outcome Score (FAOS) and the range of movement of the ankle.

There were no clinically relevant differences between the four possible SER IV fracture pattern groups with regard to the FAOS or range of movement. In this population of strictly defined SER IV ankle injuries, the presence of a malleolar fracture was not associated with a significantly worse clinical outcome than its ligamentous injury counterpart. Other factors inherent to the injury and treatment may play a more important role in predicting outcome.

Abstract. Objectives. Diabetes has been associated with greater risk of complications and prolonged postoperative recovery following ankle trauma. Our cohort study seeks to review the operative management and outcomes of ankle fractures in diabetic adults relative to non-diabetic adults. Methods. Cases were identified using ICD-10 coding criteria. 572 patients from Jan 2016–2019 presented with ankle fractures; 34 in diabetic patients. Mechanism of injury and stability were determined from the index radiograph using a validated Lauge-Hansen classification algorithm. Admission, primary post-operative and discharge radiographs were reviewed independently by two foot and ankle reconstruction specialists to assess adequacy of fixation method. 32% of diabetic patients were managed non-operatively compared to 29% of the matched non-diabetic cohort. The distribution in Lauge-Hansen fracture pattern was comparable between cohorts. Non-diabetic controls were frequency age-matched 2:1. Results. Mean length of follow-up was significantly longer for diabetics (26 weeks) compared to non-diabetics (16 weeks). Post-operative wound complications (superficial wound infection, breakdown, dehiscence) occurred in 48% of the operated diabetic ankles, compared to 5% in non-diabetics (RR 8.1, 95% CI 2.5–26.4). Reoperation (RR 4.3, 95% CI 2.5–26.4, p=0.03) and non-wound complication rates (Charcot joint, mal/non-union, metalwork infection) were likewise significantly higher (RR 3.9, 95% CI 1.4–10.8, p=0.008) in diabetics. Amongst diabetics alone, those with an HbA1c >69 mmol/mol (n=14, 41%) demonstrated a significantly higher rate still of non-wound complications (RR 4.3, 95% CI 1.1–18., p=0.03) with a trend towards higher wound complication rates (RR 3, 95% CI 0.52–17, p=0.13). Conclusions. Poorly controlled diabetes is associated with substantially greater complication rates following ankle fracture than those with well controlled or normal blood sugar; high HbA1c > 69mmol/mol is a significant predictor of complicated follow-up. Locally we recommend management strategies that are influenced by the fracture pattern stability and the presence or absence of complicated or poorly managed diabetes. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Background. Many approaches to management of medial malleolar fractures are described in the literature however, their morphology is under investigated. The aim of this study was to analyse the morphology of medial malleolar fractures to identify any association with medial malleolar fracture non-union or malunion. Methods. Patients who had undergone surgical fixation of their MMF were identified from 2012 to 2022, using electronic patient records in a single centre. Analysis of their preoperative, intraoperative, and postoperative radiographs was performed to determine their morphology and prevalence of non-union and malunion. Lauge-Hansen classification was used to characterise ankle fracture morphology and Herscovici classification to characterise MMF morphology. Results. A total of 650 patients were identified across a 10-year period which could be included in the study. The overall non-union rate for our cohort was 18.77% (122/650). The overall malunion rate was 6.92% (45/650). There was no significant difference in union rates across the Herscovici classification groups. Herscovici type A fractures were significantly more frequently malreduced at time of surgery as compared to other fracture types (p=.003). Medial wall blowout combined with Hercovici type B fractures showed a significant increase in malunion rate. There is a higher rate of bone union in patients who have been anatomically reduced. Conclusion. The morphology of medial malleolar fractures does have an impact of the radiological outcome following surgical management. Medial wall blowout fractures were most prevalent in adduction-type injuries; however, it should not be ruled out in rotational injuries with medial wall blowouts combined with and Herscovici type B fractures showing a significant increase in malunions. Herscovici type A fractures had significantly higher malreductions however the clinical implications of mal reducing small avulsions is unknown

The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in progress. Using suture-button repair devices is one of the dynamic stabilization options, however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues. The aim of this study was to investigate the performance of the novel screw-suture repair system in comparison to a suture-button stabilization of unstable syndesmotic injuries. Eight pairs of human cadaveric lower legs were CT scanned under 700 N single-leg axial loading in five foot positions – neutral, 15° external/internal rotation and 20° dorsi-/plantarflexion – in 3 different states: (1) pre-injured (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV as well as supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implants for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond. Following, all specimens were: (1) biomechanically tested over 5000 cycles under combined 1400 N axial and ±15° torsional loading; (2) rescanned. Clear space (diastasis), anterior tibiofibular distance, talar dome angle and fibular shortening were measured radiologically from CT scans. Anteroposterior (AP), axial, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via motion tracking. In each group clear space increased significantly after injury (p ≤ 0.004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (p ≤ 0.041). In addition, after reconstruction it was significantly smaller in Group 1 compared to Group 2 (p < 0.001). AP and axial movements were significantly smaller in Group 1 compared with Group 2 (p < 0.001). No further significant differences were identified/detected between the groups (p ≥ 0.113). Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior translation and axial stability of the tibiofibular joint and maintains it over time under dynamic loading. Therefore, it could be considered as a valid option for treatment of syndesmotic disruptions

The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in full progress. Using suture-button repair devices is one of the dynamic stabilization options, however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues. The aim of this study was to investigate the performance of the novel screw-suture repair system in comparison to a suture-button stabilization of unstable syndesmotic injuries. Eight pairs of human cadaveric lower legs were CT scanned under 700 N single-leg axial loading in five foot positions – neutral, 15° external/internal rotation and 20° dorsi-/plantarflexion – in 3 different states: (1) pre-injured (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV, and supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implants for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond/joint surface. Following, all specimens were: (1) biomechanically tested over 5000 cycles under combined 1400 N axial and ±15° torsional loading; (2) rescanned. Clear space (diastasis), anterior tibiofibular distance, talar dome angle and fibular shortening were measured radiologically from CT scans. Anteroposterior, axial, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via motion tracking. In each group clear space increased significantly after injury (p ≤ 0.004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (p ≤ 0.041). In addition, after reconstruction it was significantly smaller in Group 1 compared to Group 2 (p < 0.001). Anteroposterior and axial movements were significantly smaller in Group 1 compared with Group 2 (p < 0.001). No further significant differences were detected between the groups (p ≥ 0.113). Conclusions. Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior translation and axial stability of the tibiofibular joint and maintains it over time under dynamic loading. Therefore, it could be considered as a valid option for treatment of syndesmotic disruptions

Diabetes has been associated with greater risk of complications and prolonged postoperative recovery following ankle trauma. Our cohort study reviewed the operative management and outcomes of ankle fractures in diabetic adults relative to non-diabetic adults from Jan 2016–2019. Non-diabetic controls were frequency age-matched 2:1. 34 of 572 ankle fracture presentations were in diabetic patients, 32% managed non-operatively compared to 29% of the matched non-diabetic cohort. The distribution in Lauge-Hansen fracture pattern was comparable between cohorts. Mean length of follow-up was significantly longer for diabetics (26 weeks) compared to non-diabetics (16 weeks). Post-operative wound complications (superficial wound infection, breakdown, dehiscence) occurred in 48% of the operated diabetic ankles, compared to 5% in non-diabetics (RR 8.1, 95% CI 2.5–26.4). Reoperation (RR 4.3, 95% CI 2.5–26.4, p=0.03) and non-wound complication rates (Charcot joint, mal/non-union, metalware infection) were likewise significantly higher (RR 3.9, 95% CI 1.4–10.8, p=0.008) in diabetics. Amongst diabetics alone, those with an HbA1c >69 mmol/mol (n=14, 41%) demonstrated a significantly higher rate still of non-wound complications (RR 4.3, 95% CI 1.1–18., p=0.03) with a trend towards higher wound complication rates (RR 3, 95% CI 0.52–17, p=0.13). Poorly controlled diabetes is associated with substantially greater complication rates following ankle fracture than those with well controlled or normal blood sugar; high HbA1c > 69mmol/mol is a significant predictor of complicated follow-up. Locally we recommend management strategies that are influenced by the fracture pattern stability and the presence or absence of complicated or poorly managed diabetes

The management of unstable ankle fractures is challenging due the difficulty in differentiating between stable and unstable fracture patterns. The aim of our study was to examine our practice and to determine if the operative management of unstable ankle fractures resulted in significantly improved radiographic parameters. Between June 2008 and December 2008, we identified all skeletally mature patients who were diagnosed with an ankle fracture after having radiographs in the radiology department at our institution. We analysed the case notes and radiographs of these patients retrospectively. The fractures were classified according to the Weber and Lauge-Hansen classification. Radiographs were evaluated for shortening of the fibula, widening of the joint space, or malrotation of the fibula. Three measurements were used to ascertain whether the correct fibular length has been restored – the circle sign, the talocrural angle, and the tibiofibular (or Shenton) line. Of 1064 patients who had radiographs, 123 patients sustained a fracture of the ankle. There were 61 females and 62 males, with a median age of 47 years. There were 20 Weber A, 80 Weber B and 12 Weber C ankle fractures. Eleven fractures could not be classified according to the Weber classification. According to the Lauge-Hansen classification there were 44 Supination-External rotation (SER) stage II fractures, 35 Supination-External rotation (SER) stage IV fractures, and 7 Pronation-External rotation (PER) stage III fractures. In the unstable SER stage IV fractures, 30 of the 35 patients had operative treatment and there was no statistically significant difference in the average Talocrural angles in the operative (78.9°) and nonoperative groups (83.4°). None of the patients with an SER stage IV fracture managed nonoperatively had an adequate circle sign compared to 14 of the 30 patients in the operative group who had an adequate circle sign. In the PER stage III fractures 4 of the 7 patients had operative treatment. The average Talocrural angle in the operative group was 79.1° versus 75.3° in the nonoperative group, with all patients in the operative group having an adequate circle sign compared to none in the nonoperative group. The patient numbers in the PER stage III group however were too small to show a statistically significant difference. In 4 patients with unstable fracture patterns, the use of a third tubular plate to bridge a fibula fracture without an inter-fragmentary lag screw led to inadequate restoration of fibular length in all cases. It is important to recognise unstable ankle fracture patterns and, in patients treated operatively, to restore fibular length and rotation. Operative management of unstable SER stage IV and PER stage III ankle fractures can restore normal radiographic parameters. We highlight certain technical pitfalls in restoring fibular length such as the inappropriate use of the semi-tubular plate as a bridging plate

Introduction:. The Best Practice Tariff (BPT) for hip fractures was introduced in April 2010 to promote a number of quality markers, including surgery within 36 hours. We conducted an audit to see whether the introduction of the BPT has had an inadvertent adverse effect on delay to fixation of unstable ankle fractures. Method:. We compared the delay to surgery for 50 consecutive patients with unstable ankle fractures in the 2009 financial year with another 50 patients treated in the 2011 financial year, ie one year after the introduction of the BPT. There were no other changes in service in our department in this period. All radiographs were reviewed and classified using the Lauge-Hansen system by 2 surgeons. Excel was used for data analysis using unpaired T-Test and chi-squared test to assess significance. Results:. 2 patients with pilon fractures were excluded from each group. Demographics and fracture pattern between the remaining 48 patients in each group were similar. The mean delay to surgery before BPT was 2.2 days compared with 3.8 days after its introduction (p = 0.01). 7 patients waited more than 5 days for surgery before BPT compared with 17 patients after its introduction (p < 0.001). There was 1 manipulation under anaesthetic (MUA) before BPT and 8 MUAs in 7 patients after its introduction (p < 0.001). Conclusion:. There is a significant association between the introduction of BPT for hip fractures and an increase in the delay to surgery for patients with unstable ankle fractures by an average of 1.6 days. More patients waited more than 5 days for surgery and there were more MUAs. We postulate that in a resource-limited NHS, prioritizing one patient group inevitably disadvantages others. Orthopaedic trauma services must adapt to national guidance to ensure all patients are treated in a timely fashion

Medial malleolar stress fractures are uncommon even in the sporting population. They tend to occur almost exclusively in athletes involved in sports involving running and jumping. We believe that stress fractures of the medial malleolus may be the end stage of chronic anteromedial ankle impingement in elite running and jumping athletes. Anterior impingement spurs are thought to be caused by repetitive microtrauma at the limit of dorsiflexion causing subperiosteal haemorrhage and subsequent ossification. More specifically the lower surface of the anterior tibia and the anterior part of the medial malleolus undergo similar trauma during severe supination injuries. Repetitive trauma to the cartilage from the kicking action in soccer is also thought to play a part, the cartilage responding by the formation of scar tissue and subsequent calcification. We present five cases of elite athletes (three AFLplayers, one sprinter and one A Grade cricketer) who presented to our establishment with vertical stress fractures of the medial malleolus over a three year period (2004–7). In each case preoperative imaging revealed an anteromedial bony spur on the tibia. All patients had the fractures internally fixed and at the same sitting had arthroscopic debridement of the impingement spur. Average time to union was 10.2 weeks (6–16). At most recent review (average 18 months (8–37)) all fractures had united and all patients had resumed sporting activity. No patient had suffered a further fracture of the medial malleolus. We believe this region of impingement causes premature abutment of the talus on the tibia in the supination-adduction motion that in severe trauma leads to the vertical fracture through the medial malleolus according to the Lauge-Hansen classification. We therefore feel it should be addressed at the time of fracture fixation to reduce the re-fracture rate

There have been few reports with efficient treatments for neglected distal tibiofibular syndesmosis disruption. Here we will report four cases of successful anatomical reconstruction with autologous gracilis tendon, using the interference fit anchoring (IFA) system. All four cases were males between 20 and 58 years of age at the time of surgery (mean age 36 years). The post-injury period to surgery was between 7 and 59 months (mean 20.1 months), with the consultation period being from 5 to 19 months (mean 9.5 months). Radiographs at the time of injuries were all malleolar fractures of pronation-external rotation (PE) stage 3 in the Lauge-Hansen classification. Stress tests for distal tibiofibular syndesmosis were positive in all cases (dilation more than 2 mm). Arthroscopic drilling was conducted in two cases with a cartilaginous injury of trochlea of talus. Distal tibiofibular syndesmosis was anatomically repositioned and was fixed with screws after bony and soft tissues within the tibiofibular syndesmosis were removed and fibular adhesion was dissected. Ipsilateral autologous gracilis tendon was passed through foramen in the insertion of the anterior inferior tibiofibular tendon on tibia and fibula, and was fixated using the IFA system. The preoperative Japanese society for surgery of the foot (JSSF) score was from 26 to 74 points (mean 43.5) and postoperative JSSF score was from 67 to 100 (mean 89.5). In a case where there was a poor outcome, five years of post injury had passed before the surgery. Although the JSSF score improved to 67 points postoperatively (from the preoperative score of 26) in this case, arthroscopic arthrodesis was conducted 5 months postoperatively due to persistent pain. Anatomical reconstruction with autologous gracilis tendon using the IFA system showed a favorable functional prognosis overall. However, there was a case with progressive degenerated changes of injured distal tibiofibular syndesmosis due to a prolonged post-injury period resulted in a poor outcome

The June 2024 Trauma Roundup³⁶⁰ looks at: Skin antisepsis before surgical fixation of limb fractures; Comparative analysis of intramedullary nail versus plate fixation for fibula fracture in supination external rotation type IV ankle injury; Early weightbearing versus late weightbearing after intramedullary nailing for distal femoral fracture (AO/OTA 33) in elderly patients: a multicentre propensity-matched study; Long-term outcomes with spinal versus general anaesthesia for hip fracture surgery; Operative versus nonoperative management of unstable medial malleolus fractures: a randomized clinical trial; Impact of smoking status on fracture-related infection characteristics and outcomes; Reassessing empirical antimicrobial choices in fracture-related infections; Development and validation of the Nottingham Trauma Frailty Index (NTFI) for older trauma patients.

Aims

The morphology of medial malleolar fracture is highly variable and difficult to characterize without 3D reconstruction. There is also no universally accepeted classification system. Thus, we aimed to characterize fracture patterns of the medial malleolus and propose a classification scheme based on 3D CT reconstruction.

Aims

The aim of this study was to compare the functional and radiological outcomes and the complication rate after nail and plate fixation of unstable fractures of the ankle in elderly patients.

1. This paper presents a series of 135 patients with displaced ankle fractures treated by rigid internal fixation followed by early joint exercises in bed until movements were restored and followed then by full weight bearing in a plaster. 2. The advantages obtained are as follows: A high standard of reduction can be achieved and maintained. The joint movements are established before organisation of the traumatic exudate. Weight bearing in a plaster reduces the degree of disability and prevents osteoporosis. Further remedial treatment after removal of the plaster is usually unnecessary. 3. All but five of the fractures (3·7 per cent) could be classified in the manner described by Lauge-Hansen. 4. This classification is the most satisfactory of those available and is recommended for general use. 5. Anatomical reduction was obtained in 102 patients (77 per cent), with good objective clinical results in 108 patients (82 per cent). 6. The quality of the clinical result depends mostly on the accuracy of the reduction, to a lesser extent on the degree of initial displacement, and least on the type of fracture. 7. It is considered that the traditional concept of diastasis requires modification; it is felt that the term lateral ankle instability, which includes low fracture of the fibula (intraosseous diastasis) is preferable. 8. Internal fixation of the syndesmosis is to be avoided except in rare instances. 9. The incidence of arthritis is shown to depend mostly upon the accuracy of reduction; the initial degree of displacement is also of importance

The goal of treatment of an intra-articular fracture is anatomic restoration of normal anatomy and rigid internal fixation to allow for early motion. Weber Type ‘B’ ankle fractures (AO Type B and Lauge-Hansen supination-external rotation) are the most common ankle fractures that require internal fixation. Brunner and Weber first described the use of antiglide plate for treatment of these fractures in 1982. The aim of our study was to assess the functional and radiological outcomes of patients who underwent this procedure. This was a retrospective analysis of a consecutive series, reviewing patients over a ten year period, from 1990 to 1999, in a regional orthopaedic and trauma unit. There were 122 antiglide plate fixations performed in total over the period under review. Our group consisted of 64 patients who had an isolated closed lateral malleolor fracture, thereby excluding patients with open injuries and bimalleolar fractures. 6 patients were lost to follow-up. There were 25 males (age 19–64 years) and 31 females (age 13–62 years) with a mean age of 42 years. The patients were assessed by the American Orthopaedic Foot and Ankle Society (AOFAS) Score and the average follow-up was 5.8 years. The implant used was a 3.5mm AO DCP applied along the posterior surface of the lateral malleolus. This was followed by early commencement of postoperative ankle and foot exercises, allowing toe touch weight bearing out of cast until union. Our results (AOFAS Score out of 100) show that 92% (52 patients) had good to excellent result (Score> 80) with only 8% (4 patients) had a satisfactory outcome. We recommend the use of an antiglide plate because of its biomechanical stability especially in osteoporotic bones which allows for early motion and the nearly nil incidence of implant removal

Summary. The ankle X-ray has moderate diagnostic power to identify syndesmotic instability, showing large sensitivity ranges between observers. Classification systems and radiographic measurements showed moderate to high interobserver agreement, with extended classifications performing worse. Introduction. There is no consensus regarding the diagnosis and treatment of ankle fractures with respect to syndesmotic injury. The diagnosis of syndesmotic injury is currently based on intraoperative findings. Surgical indication is mainly made by ankle X-ray assessment, by several classification systems and radiographic measurements. Misdiagnosis of the injury results in suboptimal treatment, which may lead to chronic complaints, like instability and osteoarthritis. This study investigates the diagnostic power and interobserver agreement of three classification methods and radiographic measures, currently used to assess X-ankles and to identify syndesmotic injury. Patients and Methods. Twenty patients (43.2 ± 15.3yrs) with an ankle fracture, indicated for surgery, were prospectively included. All patients received a preoperative ankle X-ray, which was assessed by several observers: two orthopaedic surgeons, one trauma surgeon and two radiologists. The ankle X-ray was assessed on syndesmotic injury/stability and presence of fractures (fibula, medial/tertius malleolus). Three classification systems were used: Weber, AO-Müller (short-version n=3 options; extended-version n=27 options), Lauge-Hansen (short-version n=5 options; extended-version n=17 options) and two radiographic measurements were done: tibiofibular overlap (TFO) and ratio medial clearspace/superior clear space (MCS/SCS). All observers were instructed about the assessments before the measurements. During surgery, a proper intraoperative description of the syndesmosis was noted. Agreement (%), Intraclass Correlation Coefficients (ICC) and Kappa were calculated to determine interobserver agreement. Kappa statistic was interpreted according to Landis and Koch. To test the diagnostic power of ankle X-rays to identify syndesmotic instability, sensitivity and specificity were calculated with intraoperative findings serving as golden standard. Results. Six of 20 ankles showed syndesmotic instability intraoperatively. An overall sensitivity of 43% (specificity: 78) was found for X-rays in identifying syndesmotic instability, showing a wide range in sensitivity between observers (17–83%), with radiologists performing better (range 50–83%) than surgeons (range: 17–33%). Overall, substantial to perfect interobserver agreement (range 70–100%) was found for all short classification systems, showing an average kappa ≥0.60. The agreement reduced for more extended classification systems. E.g. observer agreement for the AO-Muller classification with 3, 9 and 27 options was respectively 85% (kappa 0.66), 68% (kappa 0.57) and 55% (kappa 0.51). One observer deviated slightly from others in all classification assessments. Removing this observer resulted in excellent agreement for all classification systems (>90%). Radiographic measurements showed moderate to high interobserver agreement, with TFO performing best (avg. ICC 0.88). Discussion/Conclusion. In ankle fractures, a preoperative X-ray has low sensitivity in detecting syndesmotic instability, showing large sensitivity ranges between observers. Further study is needed to investigate the contribution of classification systems in determining the best treatment method for syndesmotic injury. Ankle X-ray assessment using the three classification systems and radiographic measures was consistent among observers. Disagreement between observers can be attributed to intrinsic differences among the systems (e.g. stepwise classification vs. single assessment). No preference for one specific classification was found, as all showed comparable interobserver agreement. However classification systems with few options are recommended, as the observer agreement reduced with more extending classifications

Summary. Quantification of Three-Dimensional Computed Tomography (Q3DCT) is a reliable and reproducible technique to quantify and characterise ankle fractures with a posterior malleolar fragment (. www.traumaplatform.org. ). This technique could be useful to characterise posterior malleolar fragments associated with specific ankle fracture patterns. Introduction. Fixation of posterior malleolar fractures of the ankle is subject of ongoing debate1. Fracture fixation is recommended for fragments involving 25–30% of articular surface1. However, these measurements -and this recommendation- are based on plain lateral radiographs only. A reliable and reproducible method for measurements of fragment size and articular involvement of posterior malleolar fractures has not been described. The aim of this study is to assess the inter-observer reliability of Quantification using Three-Dimensional Computed Tomography (Q3DCT) –modelling. 2,3,4,5. for fragment size and articular involvement of posterior malleolar fractures. We hypothesize that Q3DCT-modelling for posterior malleolar fractures has good to excellent reliability. Patients & Methods. To evaluate inter-observer reliability of Q3DCT-modelling, we included a consecutive series of 43 patients with an ankle fracture involving the posterior malleolus and a complete radiographic documentation (radiographs and computed tomography) Fractures of the tibial plafond (pilon type fractures) were excluded. These 43 patients were divided in 3 different types (Type I, II or III) as described by Haraguchi6. Five patients of each type were randomly selected for an equal distribution of articular fragment sizes. 3D models were reconstructed by 1) creating a mask for every respective slice; 2) select the appropriate dots that separate fracture from tibialshaft; 3) connect masks of each respective slice; and 4) reconstruct a 3D-mesh. After reconstruction of 3D-models, 1) fragment volume; 2) articular surface of the posterior malleolar fragment; 3) articular surface of intact tibia and 4) articular surface of the medial malleolus were calculated by all three observers. A summary of this technique is shown on . www.traumaplatform.org. The inter-observer reliability of these measurements was calculated using the ICC, which can be interpreted as the kappa coefficient. Results. Measurements of the volume of posterior malleolar fracture fragments ranged from 357 to 2904 mm3 with an ICC of 1.00 (Confidence interval (CI) 0.999 – 1.000) Measurements of the articular surface of the posterior malleolar fracture fragment ranged from 25 to 252 mm2 with an ICC of 0.998 (CI 0.996 – 0.999); the articular surface of the intact tibia plafond ranged from 375 to 1124 mm2 (ICC 0.998, CI 0.996 – 0.999); and the articular surface of the medial malleolus ranged from 79 to 149 mm2 (ICC 0.978, CI 0.978 – 0.911). The categorical ratings for all ICC's were defined as almost perfect according to the system of Landis7. Discussion/Conclusion. This study showed that our Q3DCT-modelling technique. 2,3,4,5. is reliable and reproducible to reconstruct ankle fractures, in order to assess fracture characteristics of posterior malleolar fracture fragments. Future research will focus on the association between overall ankle fracture patterns according to Lauge-Hansen, and characterization of posterior malleolar fragment morphology. We hypothesise that supination-exorotation type fractures are associated with smaller (in volume and involved articularsurface) “pull-off” fragments, while pronation-exorotation type ankle fractures are associated with larger (in volume and involved articular surface) “push-off” fragments. The clinical relevance might be that smaller “pull-off” type fractures benefit from positioning screws, while larger “push-off” type fractures require direct open reduction and internal fixation of the posterior malleolar fragment

Aims

The primary aim of this study was to address the hypothesis that fracture morphology might be more important than posterior malleolar fragment size in rotational type posterior malleolar ankle fractures (PMAFs). The secondary aim was to identify clinically important predictors of outcome for each respective PMAF-type, to challenge the current dogma that surgical decision-making should be based on fragment size.