Background. Supination-external rotation (SER) injuries make up 80% of all ankle fractures. SER stage 2 injuries (AITFL and Weber B) are considered stable. SER stage 3 injury includes disruption of the posterior malleolus (or PITFL). In SER stage 4 there is either medial malleolus fracture or deltoid injury too. SER 4 injuries have been considered unstable, requiring surgery. The deltoid ligament is a key component of ankle stability, but clinical tests to assess deltoid injury have low specificity. This study specifically investigates the role of the components of the deep deltoid ligament in SER ankle fractures. Aim. To investigate the effect of deep deltoid ligament injury on SER ankle fracture stability. Methods. Four matched pairs (8 specimens) were tested using a standardised protocol. Specimens were sequentially tested for stability when axially loaded with a custom rig with up to 750N. Specimens were tested with: ankle intact; lateral injury (AITFL and Weber B); additional posterior injury (PITFL); additional anterior deep deltoid; additional posterior deep deltoid; lateral side ORIF. Clinical photographs and radiographs were recorded. In addition, dynamic stress radiographs were performed after sectioning the deep deltoid and then after fracture fixation to assess tilt of the talus in eversion. Results. All specimens with an intact posterior deep deltoid ligament were stable when loaded and showed no talar tilt on dynamic assessment. Once the posterior deep deltoid ligament was sectioned there was instability in all specimens. Surgical stabilisation of the lateral side prevented talar shift but not talar tilt. Conclusion. If the posterior deep deltoid ligament is intact SER fractures may be managed without surgery in a plantigrade cast. Without immobilisation the talus may tilt, risking deltoid incompetence

We randomised 50 patients with ankle fractures of Weber types B and C and a ruptured deltoid ligament treated by open reduction and internal fixation to two treatment groups to examine the influence of the repair of a ruptured deltoid ligament. No differences were found except for a longer duration of surgery in the repair group. Our findings suggest that a ruptured deltoid ligament can be left unexplored without any effect either on early mobilisation or on the long-term result

Objective: The deltoid ligament is an important stabilising structure in the ankle joint. We hypothesised that ultrasound can be used to allow early clinical assessment of ankle fracture stability accurately and quickly in Weber B and C ankle fractures thereby negating the need to perform arthrograms intra-operatively. Method: A total of 20 patients were recruited prospectively. Consent was obtained prior to surgery. Patients with Weber B or C fractures requiring surgery were recruited prospectively. Following induction of anaesthesia, ultrasound examination was performed, followed by an arthrogram under fluoroscopic screening. Operating surgeons were blinded to results. Radiographs, ultrasound and arthrographic findings were compared by a panel of orthopaedic surgeons of varying grades (2 Consultants, 2 Specialist Registrars). Results: There was 95% correlation between ultrasound and arthrogram findings. Ultrasound accurately diagnosed rupture with a sensitivity of 92% and specificity of 100%. Kappa scores for ultrasound identification of deltoid rupture was 0.8. Conclusion: We feel ultrasound exam to be a powerful adjunct tool in the management and operative planning of ankle fractures. Its versatility means it can be used in Emergency Departments and Trauma Clinics to assess ankle stability without causing the patient excessive pain and requiring an anaesthetic

Aims. Triplane ankle fractures are complex injuries typically occurring in children aged between 12 and 15 years. Classic teaching that closure of the physis dictates the overall fracture pattern, based on studies in the 1960s, has not been challenged. The aim of this paper is to analyze whether these injuries correlate with the advancing closure of the physis with age. Methods. A fracture mapping study was performed in 83 paediatric patients with a triplane ankle fracture treated in three trauma centres between January 2010 and June 2020. Patients aged younger than 18 years who had CT scans available were included. An independent Paediatric Orthopaedic Trauma Surgeon assessed all CT scans and classified the injuries as n-part triplane fractures. Qualitative analysis of the fracture pattern was performed using the modified Cole fracture mapping technique. The maps were assessed for both patterns and correlation with the closing of the physis until consensus was reached by a panel of six surgeons. Results. Fracture map grouped by age demonstrates that, regardless of age (even at the extremes of the spectrum), the fracture lines consolidate in a characteristic Y-pattern, and no shift with closure of the physis was observed. A second fracture map with two years added to female age also did not show a shift. The fracture map, grouped by both age and sex, shows a Y-pattern in all different groups. The fracture lines appear to occur between the anterior and posterior inferior tibiofibular ligaments, and the medially fused physis or deltoid ligament. Conclusion. This fracture mapping study reveals that triplane ankle fractures have a characteristic Y-pattern, and acknowledges the weakness created by the physis, however it also challenges classic teaching that the specific fracture pattern at the level of the joint of these injuries relies on advancing closure of the physis with age. Instead, this study observes the importance of ligament attachment in the fracture patterns of these injuries. Cite this article: Bone Joint J 2023;105-B(11):1226–1232

We have compared the results at a mean follow-up of 13 years (11 to 14) of two groups of supination-external rotation type-4 fractures of the ankle, in one of which there was a fracture of the medial malleolus and in the other the medial deltoid ligament had been partially or completely ruptured. Of 66 patients treated operatively between 1993 and 1997, 36 were available for follow-up. Arthroscopy had been performed in all patients pre-operatively to assess the extent of the intra-articular lesions. The American Orthopaedic Foot and Ankle Society hind-foot score was used for clinical evaluation and showed a significant difference in both the total and the functional scores (p < 0.05), but not in those for pain or alignment, in favour of the group with a damaged deltoid ligament (p < 0.05). The only significant difference between the groups on the short-form 36 quality-of-life score was for bodily pain, again in favour of the group with a damaged deltoid ligament. There was no significant difference between the groups in the subjective visual analogue scores or in the modified Kannus radiological score. Arthroscopically, there was a significant difference with an increased risk of loose bodies in the group with an intact deltoid ligament (p < 0.005), although there was no significant increased risk of deep cartilage lesions in the two groups. At a mean follow-up of 13 years after operative treatment of a supination-external rotation type-4 ankle fracture patients with partial or complete rupture of the medial deltoid ligament tended to have a better result than those with a medial malleolar fracture

Background. Ankle fractures are often associated with ligamentous injuries of the distal tibiofibular syndesmosis, the deltoid ligament and are predictive of ankle instability, early joint degeneration and long-term ankle dysfunction. Detection of ligamentous injuries and the need for treatment remain subject of ongoing debate. In the classic article of Boden it was made clear that injuries of the syndesmotic ligaments were of no importance in the absence of a deltoid ligament rupture. Even in the presence of a deltoid ligament rupture, the interosseous membrane withstood lateralization of the fibula in fractures up to 4.5mm above the ankle joint. Generally, syndesmotic ligamentous injuries are treated operatively by temporary fixation performed with positioning screws. But do syndesmotic injuries need to be treated operatively at all?. Methods. The purpose of this biomechanical cadaveric study was to investigate the relative movements of the tibia and fibula, under normal physiological conditions and after sequential sectioning of the syndesmotic ligaments. Ten fresh-frozen below-knee human cadaveric specimens were tested under normal physiological loading conditions. Axial loads of 50 Newton (N) and 700N were provided in an intact state and after sequential sectioning of the following ligaments: anterior-inferior tibiofibular (AITFL), posterior-inferior tibiofibular (PITFL), interosseous (IOL), and whole deltoid (DL). In each condition the specimens were tested in neutral position, 10 degrees of dorsiflexion, 30 degrees of plantar flexion, 10 degrees of inversion, 5 degrees of eversion, and externally rotated up to 10Nm torque. Finally, after sectioning of the deltoid ligament, we triangulated Boden's classic findings with modern instruments. We hypothesized that only after sectioning of the deltoid ligament; the lateralization of the talus will push the fibula away from the tibia. Results. During dorsiflexion and external rotation the ankle syndesmosis widened, and the fibula externally rotated after sequential sectioning of the syndesmotic ligaments. After the AITFL was sectioned the fibula starts rotating externally. However, the external rotation of the fibula significantly reduced when the external rotation torque was combined with axial loading up to 700N as compared to the external rotation torque alone. The most relative moments between the tibia and fibula were observed after the deltoid ligament was sectioned. Conclusion. Significant increases in movements of the fibula relative to the tibia occur when an external rotation torque is provided. However, axial pressure seemed to limit external rotation because of the bony congruence of the tibiotalar surface. The AITFL is necessary to prevent the fibula to rotate externally when the foot is rotating externally. The deltoid ligament is the main stabilizer of the ankle mortise

Ankle fractures are the fourth most common fracture requiring surgical management. The deltoid ligament is considered the primary stabilizer of the ankle against a valgus force. The management of the deltoid ligament in ankle fractures is currently a controversial topic no consensus exists regarding repair in the setting of ankle fractures. The purpose of this systematic review is to examine the role and indications for deltoid ligament repair in ankle fractures. A systematic database search was conducted with Medline, Pubmed and Embase for relevant studies discussing patients with ankle fractures involving deltoid ligament rupture and repair. The papers were screened independently and in duplicate by two reviewers. Study quality was evaluated using the MINORs criteria. Data extraction included post-operative outcomes, pain, range of motion (ROM), function, medial clear space (MCS), syndesmotic malreduction and complication rates. Following title, abstract and full text screening, 10 eligible studies published between 1987 and 2017 remained for data extraction (n = 528). The studies include 325 Weber B and 203 Weber C type fractures. Malreduction rate in studies with deltoid ligament repair was 7.4% in comparison to those without repair at 33.3% (p < 0.05). Eleven (4%) of deltoid ligament repair patients returned for re-operation to have implants removed in comparison to eighty three (42%) of those without repair (p < 0.05). There was no significant difference for pain, function, ROM, MCS and complication rates (p < 0.05). The mean operating time of deltoid ligament repair groups was 20 minutes longer than non-repair groups(p < 0.05). Deltoid ligament repair offers significantly lower syndesmotic malreduction rates and reduced re-operation rates for hardware removal when performed instead of transsyndesmotic screw fixation. When compared to non-repair groups, there are no significant differences in pain, function, ROM, MCS and complication rates. Deltoid ligament repair should be considered for ankle fracture patients with syndesmotic injury, especially those with Weber C. Other alternative syndesmotic fixation methods such as suture button fixation should be explored. A large multi-patient randomized control trial is required to further examine the outcomes of ankle fracture patients with deltoid ligament repair

Deltoid ligament insufficiency has been shown to decrease tibiotalar contact area and increase peak pressures within the lateral ankle mortise. Sectioning of the deltoid ligament has been shown to decrease tibiotalar contact area by 43%. This detrimental effect may create an arthritic ankle joint if left unresolved. Reconstructive efforts thus far have been less than satisfactory. Pankovich and Shivaram described the deltoid ligament as having superficial and deep components based on insertion sites. The superficial layer originates from the anterior colliculus of the medial malleolus and inserts on the navicular, calcaneus and talus. The deep layer originates from the intercollicular groove and posterior colliculus and inserts on the talus. Boss and Hintermann noted that the most consistent and strongest bands of the deltoid were the tibiocalcaneal and posterior deep tibiotalar ligaments. Chronic deltoid ligament insufficiency may be seen in several disorders including trauma and sports injuries, posterior tibial tendon disorders, prior triple arthrodesis with valgus malunion, or total ankle arthroplasty with improper component positioning or pre-existing ligament laxity. The reconstruction of the deltoid ligament in these settings may be critical to the prevention of tibiotalar arthrosis or failure of ankle prostheses from edge loading and polyethylene wear. The reconstructive technique we describe, under low torque, was able to restore eversion and external rotation stability to the talus, which was statistically similar to the native deltoid ligament. In addition, though we maximally tension this graft to give the most secure repair possible, we did not note any increased stiffness in the ankle joint through our measurement techniques. This unusual, positive secondary effect is different from that noted in studies of lateral ligament reconstruction, where ligament tensioning by all methods attempts to reproduce the native tension and not exceed it. All medial ankle ligament repairs of substance involve some type of tendon-weave (whether autograft or allograft) to achieve reconstruction. Our technique develops its strength not only from the anatomic orientation of the reconstructed ligament, but the strength of the components chosen to fix the tendon graft to the bone. The use of Endobuttons allows the entire graft to sit within the tunnels, without the potential violation of the graft ends achieved through techniques utilizing interference screw fixation. Tensioning the graft proximally through the tibia against a rigid distal construct allows greater tension to be placed on the graft at the deltoid ligament site itself than techniques which employ distal tensioning while holding the ankle into inversion. Finally, the use of a looped graft proximally secured with a post that may be moved even further proximally at the surgeon's discretion creates superior tension to achieve medial column rigidity in grossly unstable situations. Thus, given the critical importance of the deltoid ligament and the relative paucity of repair/reconstruction options available, we believe this novel approach will assist the clinician in anatomically reconstructing this challenging condition. Deltoid ligament reconstruction technique using semitendinosis allograft, with superimposed line drawing demonstrating orientation of looped graft

Determination of ankle stability is straightforward when the injury involves both the medial and lateral malleolus. However it can be challenging when the medial injury involves the deltoid ligament. Radiographic diagnosis of ankle instability highly depends on the measurement of medial clear space. As the shape of talus has been postulated akin to a trapezoid, the medial clear space may be influenced by the portion of talus occupying the mortise. Hence the medial clear space may be influenced by the position of the ankle. We sought to evaluate the impact of ankle plantarflexion and division of the deltoid ligament on the medial clear space. For the study 10 fresh-frozen cadaveric lower limbs were used. Mortise radiographs were taken at neutral, 15 and 30 degrees of plantarflexion and neutral external rotation. These measurements were repeated after dividing the deltoid ligament. To ensure consistent ankle position, the ankle was placed in a specially constructed rig, which recreated the above positions. The medial clear space and talar tilt were measured. Differences in the means between the groups were determined with the paired ‘t’ test and ANOVA within the groups. Statistical significance was set a p-value of 0.05. Increasing the plantarflexion from neutral to 30 degrees in both groups resulted in increase in the medial clear space and talar tilt. The mean increase in medial clear space became statistically significant at 30 degrees when compared to neutral. Between the groups there was a significant difference in medial clear space at 30 degrees plantarflexion. Dividing the deltoid ligament also had a significant effect on talar tilt. Plantarflexion has an influence on the medial clear space in ankle mortise views therefore pre and post ankle fixation radiographs must be interpreted with caution

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

This study aimed to ascertain whether stabilising only the AITFL is enough to prevent talar shift, and to test a simple, novel technique to reconstruct the AITFL. Twelve cadavers were used. Talar shift was measured following: 1- no ligaments cut; 2- entire deltoid ligament division; 3- group A (5 specimens) PITFL cut whilst group B (7 specimens) AITFL cut; 4- group A had AITFL divided whilst group B had the PITFL cut. Reconstruction of the AITFL was performed using part of the superior extensor retinaculum as a local flap. Measurement of talar shift was then repeated. With no ligaments divided, mean talar shift was 0.8mm for group A and 0.7mm for group B. When the deltoid ligament was divided, mean talar shift for group A was 4.8mm compared to 4.7mm in group B (P=1.00). The mean shift in group A after PITFL division was 6.0mm, increasing the talar shift by an average of 1.2mm. In group B after AITFL division mean talar shift was 8.3mm (P=0.06), increasing talar shift by an average of 3.6 mm. After division of the second tibiofibular ligament, mean talar shift in group A measured 10.0mm and in group B was 10.9mm(P=0.29). Three times more talar shift occurred after the AIFTL was divided compared to the PITFL. Repairing just the PITFL (for example by fixation of the posterior malleolus avulsion fracture) may not adequately prevent talar shift while reconstruction of the AITFL potentially restores ankle stability

Abstract. Objectives. The study aims to determine whether an arthroscopic ligament reconstruction is necessary to relieve clinical ankle instability symptoms in patients with an MRI scan showing medial or lateral ligament tear. Methods. This was a single centre retrospective case series study of 25 patients with ankle instability and ligament tear on MRI scan who had undergone arthroscopic procedures from January 2015 to December 2018. Patients were followed up for an average period of 3 years postoperatively to check for any recurrence of symptoms. Results. Of the 25 patients, 23 had ATFL tear on MRI scan, and 2 had deltoid ligament tear. Examination under anaesthesia was stable in 13 patients and unstable in 12 patients. The majority of the patients (76%) had a simple arthroscopic ankle debridement and no ligament repair. Six patients needed Brostrom repair. Conclusions. Our study has shown that in patients with MRI proven ligament tear and clinical instability, a ligament reconstruction was unnecessary in most patients. The instability symptoms of patients were relieved by simple ankle arthroscopic debridement

We performed a retrospective study of the factors affecting the outcome of Weber type-C ankle fractures in 43 patients reviewed at two to nine years after injury. We determined the functional result in relation to the use of a diastasis screw, the accuracy of reduction, the presence of tibiotalar dislocation, and of injury to the medial side of the ankle by medial malleolar fracture or deltoid ligament rupture. We assessed the use of a diastasis screw as appropriate or inappropriate on the basis of an anatomical study performed by Boden et al (1989). The diastasis screw was used unnecessarily in 19 of the 31 patients so treated, but this did not appear to affect the final functional result. The worse functional results were in ankles dislocated at the initial injury, and in those with medial malleolar fractures as opposed to those with deltoid ligament ruptures. The best results were after accurate reduction of the fibula and the syndesmosis, and greater increase in the width of the syndesmosis was associated with a worse result. Our results suggest that an increase of more than 1.5 mm in syndesmosis width is unacceptable. We recommend that when the deltoid ligament is ruptured, a diastasis screw should be used if the fibular fracture is more than 3.5 cm above the top of the syndesmosis. When a medial malleolar fracture has been rigidly repaired a diastasis screw is required if the fibular fracture is more than 15 cm above the syndesmosis

Syndesmotic stability in ankle fractures is usually assessed by pulling on the fibula with a bone hook in the coronal plane (“hook test”). Our clinical observations have suggested that instability may be more marked in the sagittal plane. Our aim was to compare movement at the tibio-fibular syndesmosis in the sagittal and coronal planes after sequential ligament division in a cadaver model. Seven specimens were used. A blinded subject was asked to perform the hook test both in the sagittal and coronal planes. Movement was assessed by measuring the displacement of parallel k-wires three consecutive times. In all specimens, the anterior tibio-fibular, interosseous and posterior tibio-fibular ligaments were sequentially divided and movement tested. In three specimens the deltoid ligament was then divided and the interosseous membrane in another three. After division of all three syndesmosis ligaments the mean displacement was 8.8mm (±3.9) in the sagittal plane and 1.5mm (±0.4) in the coronal plane. When the deltoid ligament was then divided, the displacement increased to 11.7mm (±2.4) and 3.2mm (±0.5) respectively. When the interosseous membrane was divided the measurements were 12.7mm (±4) and 3.1mm (±1.5). We conclude that distal tibio-fibular instability should be assessed in the sagittal plane

Injury to the syndesmosis occurs in 10–13% of all operative ankle fractures and there is evidence that both incomplete treatment and malreduction of the syndesmosis can lead to poor clinical outcomes. Much attention has been given to post–operative malreduction documented by computer tomography (CT), however, there is limited data about the intact positioning and relative motion of the native syndesmosis. The aim of this study is to elucidate more detailed information on the position of the fibula in the syndesmosis during simulated weight–bearing in intact state, with sequential ligament sectioning and following two reconstructive techniques. Fourteen paired, fresh–frozen human cadaveric limbs were mounted in a weight–bearing simulation jig. CT scans were obtained under simulated foot–flat loading (75 N) and in single–legged stance (700 N), in five foot positions: neutral, 15° external rotation, 15° internal rotation, 20° dorsiflexion, and 20° plantarflexion. The elements of the syndesmosis and the deltoid ligament were sequentially sectioned. One limb of each pair was then reconstructed via one of two methods: Achilles autograft and peroneus longus ligamentoplasty. The specimens were rescanned in all 5 foot positions following each ligament resection and reconstruction. Measurements of fibular diastasis, rotation and anterior–posterior translation were performed on the axial cuts of the CT scans, 1 cm proximal to the roof of the plafond. Multiple measurements were made to define the position of the fibula in the incisura. Clinically relevant deformity patterns were produced. The deformity at the incisura was consistent with clinical injury, and the degree of displacement in all ligament states was dependent on the foot position. The most destructive state resulted in the most deformity at the syndesmosis. Differences between the intact and reconstructed states were found with all measurements, especially when the foot was in external rotation and dorsiflexion. There was no significant difference with direct comparison of the reconstructions. This study has detailed the motion of the fibula in the incisura and its variation with foot position. Neither reconstruction was clearly superior and both techniques had difficulty in the externally rotated and dorsiflexed foot positions. This study design can serve as a model for future ex–vivo testing of reconstructive techniques

This study investigated athletes presenting with grade II syndesmosis injuries and identified the clinical and radiological factors important in differentiating a stable from dynamically unstable injury and those findings associated with a longer recovery and return to sport. Sixty-four athletes were prospectively assessed with an average follow-up of 37 months (range 24–66 months). Athletes with an isolated distal syndesmosis (+/− medial deltoid ligament) injury were included. Those athletes with a concomitant ankle fracture were excluded. Those considered stable (grade IIa) were treated conservatively with a boot and progressive rehabilitation. Those with clinical signs of instability underwent arthroscopy and if instability was confirmed (grade IIb) the syndesmosis was stabilized surgically. The clinical assessment of injury to individual ligaments of the ankle and syndesmosis were recorded along with MRI findings, complications and time to return to play. All athletes returned to the same level of professional sport – 28 with IIa injuries returned at a mean of 45 days whereas the 36 with grade IIb injuries returned to play at a mean of 64 days (p< 0.001). Clinical assessment of injury to the ligaments of the syndesmosis correlated well with MRI findings. Those with a positive squeeze test were 9.5 times as likely and those with a deltoid injury 11 times more likely to have an unstable syndesmosis confirmed arthroscopically. The combination of injury to the AITFL and deltoid ligament was associated with a delay in return to sport. Concomitant injury to the ATFL indicated a different mechanism of injury with the syndesmosis less likely to be unstable and was associated with an earlier return to sport. Clinical and MRI findings may differentiate stable from dynamically unstable grade II injuries and identify which athletes may benefit from early arthroscopic assessment and stabilization. It also suggests the timeframe for expected return to play

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.

The most important determinant in the treatment of malleolar fractures is stability. Stable fractures have an intact deep deltoid ligament and do not displace with functional treatment. If the deep deltoid/medial malleolar complex is disrupted, the talus is at risk of displacement. Weber (2010) showed that weightbearing radiographs predicted stability in patients with undisplaced ankle fractures. We developed clinical criteria for potential instability and applied them to a prospective series of patients. Criteria included: medial clear space of < 4mm; medial tenderness, bruising or swelling; a fibular fracture above the syndesmosis; a bimalleolar or trimalleolar fracture; an open fracture; a high-energy fracture mechanism. A consecutive, prospectively documented series of 37 patients chose functional brace treatment of potentially unstable fractures. Weightbearing radiographs were performed in the brace before treatment, and free of brace at clinical union (6–9 weeks in all patients). Patients were encouraged to bear full weight and actively exercise their ankles in the brace. All fractures healed without displacement. The risk of displacement was 0% (95% CI 0–11.2%). This preliminary series gives support for the use of weightbearing radiographs to guide treatment of undisplaced ankle fractures

Traditional screw fixation of the syndesmosis can be prone to malreduction. Suture button fixation however, has recently shown potential in securing the fibula back into the incisura even with intentional malreduction. Yet, if there is sufficient motion to aid reduction, the question arises of whether or not this construct is stable enough to maintain reduction under loaded conditions. To date, there have been no studies assessing the optimal biomechanical tension of these constructs. The purpose of this study was to assess optimal tensioning of suture button fixation and its ability to maintain reduction under loaded conditions using a novel stress CT model. Ten cadaveric lower limbs disarticulated at the knee were used. The limbs were placed in a modified external fixator frame that allows for the application of sustained torsional (5 Nm), axial (500 N) and combined torsional/axial (5Nm/500N) loads. Baseline CT scans of the intact ankle under unloaded and loaded conditions were obtaining. The syndesmosis and the deltoid ligament complex were then sectioned. The limbs were then randomised to receive a suture button construct tightened at 4 kg force (loose), 8 kg (standard), or 12 kg (maximal) of tension and CT scans under loaded and unloaded conditions were again obtained. Eight previously described measurements were taken from axial slices 10 mm above the tibiotalar joint to assess the joint morphology under the intact and repair states, and the three loading conditions: a measure of posterolateral translation (a, b), medial/lateral translation (c, g), a measure of anterior-posterior translation (f), a ratio of anterior-posterior translation (d/e), an angle (Angle 1) created by a line parallel to the incisura and the axis of the fibula, and an angle (Angle 2) created between the medial surfaces of two malleoli. These measurements have all been previously described. Each measurement was taken at baseline and compared with the three loading scenarios. A repeated measures ANOVA with a Bonferroni correction for multiple comparisons was used to test for significance. Significant lateral (g, maximum 5.26 mm), posterior (f, maximum 6.42 mm), and external rotation (angle 2, maximum 11.71°) was noted with the 4 kg repair when compared to the intact, loaded state. Significant posterior translation was also seen with the both the 8 kg and 12 kg repairs, however the incidence and magnitude was less than with the 4 kg repair. Significant overcompression (g, 1.69 mm) was noted with the 12 kg repair. Suture button constructs must be appropriately tensioned to maintain reduction and re-approximate the degree of physiological motion at the distal tibiofibular joint. If inserted too loosely, these constructs allow for supraphysiologic motion which may have negative implications on ligament healing. These constructs also demonstrate overcompression of the syndesmosis when inserted at maximal tension however the clinical effect of this remains to be determined