Which ankle fractures require syndesmotic stabilization?

Do lateral ankle ligaments contribute to syndesmotic stability: a finite element analysis study

Whether the lateral ankle ligaments contribute to syndesmotic stability is still controversial and has been the subject of frequent research recently. In our study, we tried to elucidate this situation using the finite element analysis method. Intact model and thirteen different injury models were created to simulate injuries of the lateral ankle ligaments (ATFL, CFL, PTFL), injuries of the syndesmotic ligaments (AITFL, IOL, PITFL) and their combined injuries. The models were compared in terms of LFT, PFT and EFR. It was observed that 0.537 mm LFT, 0.626 mm PFT and 1.25° EFR occurred in the intact model (M#1), 0.539 mm LFT, 0.761 mm PFT and 2.31° EFR occurred in the isolated ATFL injury (M#2), 0.547 mm LFT, 0.791 mm PFT and 2.50° EFR occurred in the isolated AITFL injury (M#8). The LFT, PFT and EFR amounts were higher in the both M#2 and M#8 compared to the M#1. LFT, PFT and EFR amounts in M#2 and M#8 were found to be extremely close. In terms of LFT and PFT, when we compare models with (LFT: 0.650 mm, PFT: 1.104) and without (LFT: 0.457 mm, PFT: 1.150) IOL injury, it is seen that the amount of LFT increases and the amount of PFT decreases with IOL injury. We also observed that injuries to the CFL, PTFL and PITFL did not cause significant changes in fibular translations and PFT and EFR values show an almost linear correlation. Our results suggest that ATFL injury plays a crucial role in syndesmotic stability.

How has acute syndesmotic injury management evolved over the last decade? Results from a national survey

The management of acute distal tibiofibular syndesmotic injuries has evolved over time and therefore, the aim of this study was to evaluate the use of different methods and the changes regarding management of distal tibiofibular syndesmotic injury among Dutch trauma- and orthopedic surgeons. A digital survey based on a previous survey conducted in 2012 was sent to (orthopedic) trauma surgeons from all different hospitals in the Netherlands. Sixty out of the 68 invited hospitals completed at least one survey (88.2 %). For Weber B or low Weber C fractures, there was a preference for the use of a single syndesmotic screw (SS)(73.6 %), while two screws were mainly used in Maisonneuve fractures (89.3 %). Furthermore, there was a clear preference for 3.5-mm screws, engaging three cortices, 2 to 4-cm above the tibiotalar joint. There is a significant decrease in routine removal of SSs (23.2 % compared to 87.0 % in 2012, p < 0.01). The percentage of hospitals in this survey that used the suture button (SB) was relatively low: 8.3 % for low fibular fractures and 5.0 % in high fibular fractures. In conclusion, the most striking difference compared to 2012 is the large decline in routine removal of the SS, which is in line with current literature. The SS is mainly implanted engaging three cortices, placed 2-4 cm above the tibiotalar joint and 3.5 mm in size and for the treatment of Maisonneuve fractures, two screws are preferred over a single SS. LEVEL OF EVIDENCE: Level III.

Comparative analysis of internal fixation modalities for PER type IV ankle fractures: a finite element study

BACKGROUND

There are many options for the surgical treatment of pronation external rotation (PER) type IV ankle fractures, including the use of fibular plates and screws, the aim of this study was to investigate the biomechanical stability and safety of different internal fixation methods for PER type IV ankle fractures via finite element analysis.

METHODS

A three-dimensional finite element model of the ankle joint and the whole foot of a healthy 26-years-old adult male was established and validated based on computed tomography images of his lower limb, and a computer-aided design was used to produce a PER type IV ankle fracture and plate and screw model. Four different internal fixation modes were simulated, including a (all ankle fixation-utilizing a fibular plate and screws for comprehensive stabilization of the ankle), b (inferior tibiofibular joint fixation + all ankle fixation), c (inferior tibiofibular joint fixation + unfixed anterior ankle), and d (inferior tibiofibular joint fixation + unfixed anterior and posterior ankles). The results of the four different fixation methods were compared via finite element analysis, and the von Mises stresses. The displacements of the four different fixation methods were analyzed as the output indices.

RESULTS

There were no significant differences between the results of using fibular plates and screws and the displacement of fracture breaks among the four internal fixation modalities. The von Mises stress in the tibiotalar joint, median ankle, posterior ankle, and anterior ankle was minimized in the working condition of d, d, b, and d respectively. The von Mises stress in the fibular plate and screws was minimized in the working condition of a. The von Mises stress in the distal fibula was minimized in the working condition of a. However, the stress was mainly concentrated at the attachment point of the inferior tibiofibular anterior ligament, and in the working condition with inferior tibiofibular joint fixation, the stress was significantly concentrated in the inferior tibiofibular joint screw in all the fibular plates and screws.

CONCLUSIONS

The results of this study demonstrate the feasibility of using finite element analysis to compare the biomechanical stability and safety of four configurations of fibular plates and screws for treating PER type IV ankle fractures. All four modalities provided comparable biomechanical stability and safety, showing no significant differences. However, the current limitations of the finite element analysis methodology preclude specific clinical inferences. Further refinement of the methodology in future studies is necessary to enable reliable clinical applications.

A Prospective Study on Fixation of Syndesmotic Ankle Injury: Tight Rope Versus Screw Fixation

Background Syndesmotic injury can result in significant instability and long-term complications if not treated correctly. Traditional management has involved transyndesmotic screw fixation, but a newer technique, the tight rope system, has been developed to mitigate some of the issues related to screw fixation, such as hardware discomfort and the necessity for hardware removal. Methods In this randomized, prospective study, 32 patients with ankle injuries requiring syndesmotic fixation were equally divided into two groups: one receiving the tight rope system (n=16) and the other undergoing screw fixation (n=16). The patients were monitored for six months following surgery. The study measured outcomes such as time to weight-bearing, range of motion, pain levels, functional outcomes using the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Scale, and complication rates. Results Both groups had comparable demographic and injury profiles. The tight rope group achieved weight-bearing significantly earlier (6.19 ± 0.9 weeks vs. 7.13 ± 0.95 weeks, p=0.008) and had better functional outcomes at six months (87.5% excellent AOFAS scores vs. 37.5%, p=0.003) compared to the screw fixation group. The range of motion and pain scores were similar between the groups. Different complications were observed: screw breakage was more common in the screw fixation group, while the tight rope group experienced more laxity. Overall complication rates were similar. Conclusion Both techniques were effective in reducing pain and maintaining range of motion. However, the tight rope system allowed for earlier weight-bearing and better functional outcomes at six months. These results indicate that the tight rope system may provide certain advantages in treating syndesmotic injuries, although the choice of technique should be tailored to the specific injury and patient factors.

Patterns of Anterior Inferior Tibiofibular Ligament Avulsion Fracture Accompanied by Ankle Fracture

The anterior inferior tibiofibular ligament (AITFL) avulsion fracture accompanying an ankle fracture can compromise ankle stability, necessitating accurate evaluation and a clear understanding of its pathophysiology.. The aim of this study was to investigate the association between AITFL avulsion fracture and Lauge-Hansen, Wagstaffe classification. A retro-prospective study was conducted at a university-affiliated tertiary care medical center. We selected 128 patients who underwent surgery at our institution between January 2013 and July 2017 and analyzed the association between AITFL avulsion fracture and the foot position. According to the modified Wagstaffe classification system, there were 39 cases of type II, followed by 9 cases of type III and 8 cases of type IV. Of the7 pronation-abduction fractures, 3 were AITFL avulsion fracture (43%), while of the 21 pronation-external rotation fractures, 9 were AITFL avulsion fracture (43%). Of the 95 supination-external rotation fractures, there were 56 cases (59%) of AITFL avulsion fractures. Of the pronation fractures, 0% were fibular avulsion fractures and 43% were tibial avulsion fractures. Of the supination fractures, 44% were fibular avulsion fractures and 16% were tibial avulsion fracture. The difference in the ratio of fibular to tibial avulsion fractures between pronation and supination fractures was significant (p < .001). These results suggest that tibial avulsion fractures of type IV in the modified Wagstaffe classification and pronation fractures occur due to collision with the anterolateral corners of the distal bone when the talus externally rotates. Moreover, in cases of pronation fractures, a new type of AITFL avulsion fracture has been observed.

Center-Center Surgical Technique With Dynamic Syndesmosis Fixation: A Cadaveric Pilot Study

The objective of this cadaveric biomechanical study was to evaluate if the center-center surgical technique is a reliable and repeatable method of achieving proper syndesmotic reduction when using dynamic syndesmotic fixation. Nine fresh frozen above-knee cadaveric lower extremities were used. Computerized tomography (CT) scans were first obtained for each intact specimen as the baseline for comparison. A simulated complete syndesmotic disruption was created by transection of all deltoid and syndesmotic ligaments. Instability of the ankle was confirmed with stress imaging using fluoroscopy. Each unstable specimen was repaired using the center-center surgical technique with dynamic syndesmosis fixation. A series of measurements from the axial CT images of intact and repaired specimens were used to determine the anatomic distal tibiofibular relationships for comparison of changes from intact to postfixation. All radiographic measurements were performed by 4 independent foot and ankle surgeons. The level of inter-rater reliability for all the measurements was found to be "moderate" to "excellent" agreement (ICC value: 0.865-0.983, 95% confidence interval: 0.634-0.996). There was no statistical difference found between rotational alignment of native and postfixation (a/b: p = .843; b-a: p = .125; θ: p = .062). There was a statistical difference detected for lateral alignment at the center of fibularis incisura between native and postfixation (average: -0.6 ± 0.8 mm, range: -2.3 to 1.2 mm, p < .001). There was no statistical difference found for the anteroposterior translation alignment between native and postfixation (d/e: p = .251; f: p = .377). This study demonstrated the use of the center-center surgical technique as a viable and repeatable method for achieving anatomical reduction of the tibiofibular syndesmosis when used with dynamic fixation modalities.

Functional outcome of routine versus on-demand removal of the syndesmotic screw

Aims

The primary aim of this study was to present the mid-term follow-up of a multicentre randomized controlled trial (RCT) which compared the functional outcome following routine removal (RR) to the outcome following on-demand removal (ODR) of the syndesmotic screw (SS).

Methods

All patients included in the 'ROutine vs on DEmand removal Of the syndesmotic screw' (RODEO) trial received the Olerud-Molander Ankle Score (OMAS), American Orthopaedic Foot and Ankle Hindfoot Score (AOFAS), Foot and Ankle Outcome Score (FAOS), and EuroQol five-dimension questionnaire (EQ-5D). Out of the 152 patients, 109 (71.7%) completed the mid-term follow-up questionnaire and were included in this study (53 treated with RR and 56 with ODR). Median follow-up was 50 months (interquartile range 43.0 to 56.0) since the initial surgical treatment of the acute syndesmotic injury. The primary outcome of this study consisted of the OMAS scores of the two groups.

Results

The median OMAS score was 85.0 for patients treated with RR, and 90.0 for patients treated with ODR (p = 0.384), indicating no significant difference between ODR and RR. The secondary outcome measures included the AOFAS (88.0 in the RR group and 90.0 for ODR; p = 0.722), FAOS (87.5 in the RR group and 92.9 for ODR; p = 0.399), and EQ-5D (0.87 in the RR group and 0.96 for ODR; p = 0.092).

Conclusion

This study demonstrated no functional difference comparing ODR to RR in syndesmotic injuries at a four year follow-up period, which supports the results of the primary RODEO trial. ODR should be the standard practice after syndesmotic screw fixation.

Anatomical Augmentation Using Suture Tape for Acute Syndesmotic Injury in Maisonneuve Fracture: A Case Report

Ankle syndesmosis is crucial to the integrity of the ankle joint and weight-bearing; an injury to this structure can lead to significant disability. The treatment methods for distal syndesmosis injuries are controversial. The representative treatment methods include transsyndesmotic screw fixation and suture-button fixation, and good results with suture tape augmentation have recently been reported. However, an augmentation using suture tape is only possible when the posterior inferior tibiofibular ligament (PITFL) is intact. This study describes the case of an unstable syndesmosis injury, accompanied by anterior inferior tibiofibular ligament (AITFL) and PITFL injuries, which were treated successfully using suture tape. A 39-year-old male patient sustained right ankle damage while skateboarding. His leg and ankle radiographs revealed a widening of the medial clear space, a posterior malleolus fracture, a reduced “syndesmosis overlap” compared with the contralateral side, and a proximal fibula fracture. The magnetic resonance imaging revealed ruptured deltoid ligaments, accompanied by AITFL, PITFL, and interosseous ligament injuries. A diagnosis of a Maisonneuve fracture with an unstable syndesmotic injury was made. The patient underwent an open syndesmotic joint reduction, along with an AITFL and PITFL augmentation. This anatomical reduction was confirmed using intraoperative arthroscopy and postoperative computed tomography (CT). An axial CT that was performed at the 6-month follow-up exam revealed a similar alignment of the syndesmosis between the injured and uninjured sides. There were no surgical complications and the patient did not complain of discomfort in his daily life. At the 12-month follow-up exam, a good clinical outcome was confirmed. As a treatment for unstable syndesmosis injury, ligament augmentation using suture tape shows satisfactory clinical outcomes and can be considered as a useful and reliable method for anatomical restoration and rapid rehabilitation.

Primary Deltoid Repair for Ankle Fracture Using All-Suture Anchors

Primary repair of the deltoid ligament is a common surgical option for unstable ankle fracture. However, controversy exists regarding whether such repair is necessary or provides any benefit to patient outcomes. A retrospective study was performed following acute deltoid repairs using all-suture bone anchors. Patients at 2 surgical centers were included when they were over 18 years old at surgery, had a medial clear space (MCS) greater than 4 mm preoperatively, and had at least 6 months of follow-up. Subjective outcomes were measured with PROMIS, FAAM, and numeric rating scale. Preoperative and follow-up scores were compared with t tests (p < .05). For the 47 patients identified, age at time of surgery was 30.6 ± 14.9 years (range 15.4-65.0 years). Follow-up data were captured for 36 (73%) of the patients at 75 ± 37 weeks (range 18-169 weeks) after surgery. Mean time to weightbearing was 4 ± 1 weeks (range 1-7 weeks). Patients returned to sport 14 ± 5 weeks after surgery (range 8-41 weeks). Various complications consisted of wound infection, superficial dehiscence, and complex regional pain syndrome (CRPS). The PROMIS, FAAM, and NRS patient outcome scores improved significantly from preoperative to postoperative follow-up. Significant reduction in the radiographic MCS postoperatively occurred in all patients. These findings suggest primary deltoid repair when associated with ankle fracture to be a safe procedure and has the potential of allowing early weightbearing and return to sports.

Value of Intraoperative 3D Imaging on the Quality of Reduction of the Distal Tibiofibular Joint When Using a Suture-Button System

BACKGROUND

The quality of reduction of the distal tibiofibular joint (DTFJ) has a major impact on the outcome. Novel suture-button systems as well as intraoperative 3D imaging can be applied to increase the quality of DTFJ reduction intraoperatively. The individual effect of either remains unknown. The aim of this study was to investigate the value of intraoperative 3D imaging on the quality of reduction of the DTFJ when using a suture-button system.

METHODS

Retrospective, radiographic study including adult patients who underwent surgical stabilization of the syndesmosis with a suture-button system for acute, unilateral, unstable syndesmotic injuries with postoperative bilateral CT imaging. The use of an intraoperative 3D scan was the individual surgeon's choice. Assessed was whether the intraoperative 3D imaging had an influence on the postoperative quality of DTFJ reduction and revision rates. These findings were put in perspective to the correction potential of the suture-button system.

RESULTS

A total of 147 patients were included; 76 of these received an intraoperative 3D imaging. Neither the rate of formal malreduction (17% vs 17%) nor the postoperative revision rate (4% vs 3%) differed significantly between patients with or without intraoperative 3D imaging. Intraoperative 3D imaging revealed a false-negative rate of 14%. The intrinsic correction potential of the suture-button system reduced the number of formally malreduced DTFJs in both groups by 51%.

CONCLUSION

The additional value of intraoperative 3D imaging to assess the quality of DTFJ reduction in our series did not improve syndesmotic reduction when using a flexible suture-button system.

LEVEL OF EVIDENCE

Level III, retrospective comparative cohort study.

Syndesmosis Malposition Assessed on Weight-Bearing CT Is Common After Operative Fixation of Intra-articular Distal Tibia Plafond Fracture

OBJECTIVES

To evaluate reliability of measurement techniques for syndesmosis position after operative fixation of distal tibia plafond fracture on weight-bearing computed tomography (WBCT), identify risk factors for syndesmosis malposition, and determine if syndesmosis malposition is associated with higher pain and lower physical function.

DESIGN

Prospective cohort study.

SETTING

Three Level 1 trauma centers.

PARTICIPANTS

Twenty-six subjects who underwent open reduction and internal fixation of distal tibia plafond fractures with bilateral ankle WBCT 1 year or greater after injury were included in the study.

INTERVENTION

Operative fixation of distal tibia plafond fracture.

MAIN OUTCOME MEASUREMENT

Fibula position in the tibia incisura, injury characteristics, and patient-reported outcomes were the main outcome measurements.

RESULTS

Interrater reliability for syndesmosis position measurements were excellent for the Phisitkul technique on both injured and healthy ankles (intraclass correlation coefficients [ICCs]: 0.93-0.98). The Nault technique demonstrated moderate-to-excellent interrater reliability (ICCs: 0.67-0.98), apart from the angle of rotation measurement (ICCs: 0.18-0.67). Sixteen of 26 subjects (62%) had syndesmosis malposition defined as >2 mm difference comparing the tibial-fibular relationship in injured and uninjured ankles using these 2 methods. Patients with syndesmosis malposition reported lower Foot and Ankle Ability Measure: Activities of Daily Living scores; other recorded patient-reported outcomes were not significantly different.

CONCLUSIONS

Measurement techniques for syndesmosis position on WBCT were reliable after operative fixation of distal tibia plafond fracture. Syndesmosis malposition is common after these injuries and predicted impaired physical function.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

3D Mapping of the Lateral Malleolus Fractures for Predicting Syndesmotic Injuries in Supination External Rotation Type Ankle Fractures

Supination external rotation (SER) type ankle fracture is the most common ankle fracture in the Lauge-Hansen classification and is often accompanied with syndesmotic injury. However, the mechanism of this injury is indistinct and a suggestive role can be given by preoperative imaging. This study was to preoperatively predict whether SER type ankle fractures are accompanied with syndesmotic injuries by the means of lateral malleolus fracture mapping. One hundred and forty-eight patients diagnosed with SER type ankle fractures were retrospectively enrolled in this study. The baseline data were collected and computed tomography data were reconstructed in 3-dimensional (3D) model. Patients were divided into stable and unstable groups according to intraoperative Cotton test and whether the inferior tibiofibular screw was placed. All fracture lines were superimposed on the ankle template to create a fracture map, and the data on the fracture map were further measured. Logistic regression was conducted to identify relevant factors and the cutoff values were given using receiver operating characteristic curves. Forty-one patients were enrolled in the unstable group and 107 patients were enrolled in the stable group. The lateral malleolus fracture lines of the unstable group were higher and steeper than that in the stable group on lateral and posterior views. The fracture height of the posterior cortex and peak height were the significant contributing factors, and the cut-off values of posterior cortex, peak height and inclination angle were 40.35 mm (sensitivity: 78%, specificity: 82%), 55.34 mm (sensitivity: 85%, specificity: 70%) and 55.6° (sensitivity: 66%, specificity: 86%), respectively. In general, when the fracture lines of the lateral malleolus were high and steep, it was usually indicative of a syndesmotic injury and can be predicted by the preoperative 3D reconstruction of fracture height of posterior cortex, peak height and inclination angle. If the cut-off values of these indicators are exceeded, the syndesmotic injuries may be presented and need to be verified in the intraoperative Cotton test to decide whether to insert an inferior tibiofibular screw.

Treatment and outcome of a patient with low-energy 'Logsplitter' injury

The low-energy ‘Logsplitter’ fracture, caused by a sprain or fall, is characterized by an intact or slightly separated inferior tibiofibular joint. Compared with the high-energy ‘Logsplitter’ fracture, this atypical subtype is rarely seen and is easily missed. Here, the case of a 33-year-old male patient with a fractured right ankle as a result of a sprain during walking is reported. The patient initially received routine surgical treatment comprising internal fixation of the fibular, medial and posterior malleoli. Unexpectedly, post-surgery imaging examinations revealed that the medial clear space of the right ankle had widened to 6 mm, due to incomplete reduction of the lateral malleolus, shortening and rotation of the fibula, and an unreduced avulsion fracture block of the anterior malleolus. A revision surgery was then performed to anatomically reduce and fix the lateral malleolus, as well as the anterior malleolus avulsion fracture. During 5 months following surgery, the patient achieved good fracture union and functional restoration of the right ankle. For this rare injury, the present case demonstrates that complete restoration of the fracture is required to achieve good clinical efficacy.

Cerrahi Tedavi uygulanmış Ayak Bileği Kırıklarının Klinik, Radyolojik ve Fonksiyonel Sonuçlarının Değerlendirilmesi

Amaç Ayak bileği vücudun yürüme fonksiyonunda önemli bir eklemdir. Deplase ve stabil olmayan kırıkların ve eklem uyumunun konservatif yöntemlerle sağlanamadığı durumlarda cerrahi tedavi gerekir. Cerrahi tedavinin temel amacı, normal bir tibiotalar ilişki için talusun ayak bileği içindeki anatomik pozisyonunu sağlamaktır. Ayak bileği kırıklarında tedavi sonuçlarını etkileyen en önemli faktörler kırık tipi, malleol kırığı sayısı, redüksiyonun yeterliliği ve hastanın yaşıdır. Yöntem Ocak 2006-Ekim 2015 tarihleri arasında polikliniğimize başvuran, ayak bileği kırığı tanısı alan ve cerrahi tedavi uygulanan 73 hasta retrospektif olarak klinik, fonksiyonel ve radyolojik olarak değerlendirildi ve sağlam ayak bileği ile karşılaştırıldı. Bulgular Ameliyat olan hastalardan; 34'ünde bimalleol kırığı (%46.58), 8'inde (%10.96) trimalleol kırığı, 14'ünde lateral malleol kırığı (%19.18), 13'ünde medial malleol kırığı (%17.81), 1’inde posterior malleol kırığı ile birlikte ayak bileği çıkığı (%1.37) ve 1’inde de medial malleol kırığı ile birlikte arka malleol kırığı vardı (%1.37). Lauge Hansen sınıflamasına göre en sık SER (Supinasyon Eksternal Rotasyon) kırık tipi (14 olgu) (%19.18), ardından ikinci en sık PER (Pronasyon Eksternal Rotasyon) kırık tipi (14 olgu) (%19.18) idi. belirlendi. Supinasyon Addüksiyon tipi 10 vaka (% 13.70) ve PAP (Pronasyon Abdüksiyon) tipi 7 vaka (% 9.59) vardı. Danis - Weber sınıflamasına göre en sık Tip C (21 vaka) (% 52.50) ve ikinci en sık Tip B (14 vaka) (% 35,00) idi. Kaynama süresi kırık tipine göre incelendiğinde istatistiksel olarak anlamlı farklılık gözlenmedi (p=0,064). Her 3 skorlama sistemine göre istatistiksel olarak anlamlı olmasa da ameliyat öncesi bekleme süresinin uzaması ile kötü sonuç oranı arttı. Weber'e göre mükemmel iyileşme 18-42 yaş grubunda istatistiksel olarak anlamlı derecede yüksek bulundu (p=0,029) ve Weber'e göre bimalleolar kırıklarda kötü sonuç anlamlı olarak daha yüksek bulundu. Weber protokolüne göre lateral malleol kırığında mükemmel sonuç anlamlı olarak daha yüksek bulundu. Posterior malleol saptanan trimalleolar kırığı olan hastaların AOFAS (Amerikan Ortopedik Ayak ve Ayak Bileği Derneği) skoru 92.11; Buradan posterior malleol stabilizasyonunun ayak bileği fonksiyonel skorunu olumlu etkilediği belirlendi. Sonuç Ayak bileği kırıklarında cerrahi tedavi uygulanacaksa fibula uzunluğu sağlanmalı, eklem yüzeyinin anatomik olarak küçültülmesi amacıyla rijit iç tespit yapılmalı ve ayak bileği hareketlerine erken başlanmalıdır.

A Tension-Band Wiring Technique for Direct Fixation of a Chaput Tubercle Fracture: Technical Note

Few reports have described direct fixation of the Chaput tubercle; screw fixation is usually employed. Herein, we introduce a novel technique for Chaput tubercle fixation using tension-band wiring. This technique is applicable to fractured tubercles of various sizes and has the advantage that the fragment breakage that may occur during screw fixation is impossible. In addition, our technique increases fixation strength.

Utility of WBCT to Diagnose Syndesmotic Instability in Patients With Weber B Lateral Malleolar Fractures

BACKGROUND

Diagnosing syndesmotic instability accompanying Weber B ankle fractures can be challenging. This study aimed to evaluate the ability of weight-bearing computed tomography (WBCT) to diagnose syndesmotic instability using one-dimensional, two-dimensional, and three-dimensional measurements among patients with unilateral Weber B lateral malleolar fractures with symmetric medial clear space (MCS) on initial radiographs and yet demonstrated operatively confirmed syndesmotic instability.

METHODS

The treatment group included 23 patients with unilateral surgically confirmed syndesmotic instability accompanying Weber B ankle fractures who underwent preoperative bilateral foot and ankle WBCT. The control group included 18 unilateral Weber B ankle fracture patients without syndesmotic instability who underwent bilateral WBCT. Measurements on WBCT images included the following: (1) syndesmotic area, (2) anterior, middle, and posterior distal tibiofibular distance, (3) fibular rotation, (4) distance from fibular tip to plafond, (5) fibular fracture displacement, and (6) MCS distance. In addition, the following volumetric measurements were calculated: (1) syndesmotic joint volume from the tibial plafond extending to 3 and 5 cm proximally, (2) MCS volume, and (3) lateral clear space volume. Area under the receiver operating characteristic curve analysis and Delong test were used, and optimal cutoff values to distinguish between stable and unstable syndesmosis were determined using Youden J statistic.

RESULTS

Among patients with unilateral syndesmotic instability and Weber B ankle fractures, all WBCT measurements were significantly greater than uninjured side, except MCS distance, syndesmotic area, and anterior and posterior tibiofibular distances (P values <0.001 to 0.004). Moreover, syndesmosis volume spanning from the tibial plafond to 5 cm proximally had the largest area under the curve of 0.96 (sensitivity = 90%; specificity = 95%), followed by syndesmosis volume up to 3 cm proximally (area under the curve = 0.91; sensitivity = 90%; specificity = 90%). Except for MCS volume and distal fibular tip to tibial plafond distance, the control group showed no side-to-side difference in any parameter.

CONCLUSION

Syndesmotic joint volume measurements seem to be best suited to diagnose syndesmotic instability among patients with Weber B ankle fractures, compared with other two-dimensional and three-dimensional WBCT measurements.

LEVEL OF EVIDENCE

Level III, comparative diagnostic study.

The Clinical Efficacy of Suture-Button Fixation and Trans-Syndesmotic Screw Fixation in the Treatment of Ankle Fracture Combined With Distal Tibiofibular Syndesmosis Injury: A Retrospective Study

Twenty percent of ankle fractures present with concomitant syndesmosis injury which results in poor clinical outcomes. Surgical stabilization of the syndesmosis can be achieved with either trans-syndesmotic screws or a suture button device. The aim of this study is to investigate the clinical efficacy of suture button fixation and trans-syndesmotic screw fixation in the treatment of ankle fracture combined with distal tibiofibular syndesmosis injury. A retrospective analysis was conducted by enrolling 76 patients with ankle fractures combined with distal tibiofibular syndesmosis injury who were admitted in our trauma center from January 2018 to January 2019, including 34 cases of suture button group and 42 cases of the syndesmotic screw group with a mean follow-up period of 16 ± 7 (range 12-21) months. The demographic data included gender, age, injury mechanism, AO classification and the operation duration were recorded, the radiographic and clinical outcomes were determined by tibiofibular clear space, tibiofibular overlap distance, complications, and the Olerud-Molander Ankle Score at the last follow-up. All the indexes were compared between the 2 groups to discover the related statistical differences. With the numbers available, no significant difference could be detected in the surgical duration, tibiofibular clear space, tibiofibular overlap distance, total complication rate, and middle-term Olerud-Molander Ankle scores between the 2 groups. However, the suture button fixation group showed higher early stage Olerud-Molander Ankle scores (p = .027) and shorter full weightbearing time (p = .018) than that of syndesmotic screw fixation group. Considering the outcomes, we conclude that the suture button fixation not only shows equivalent efficacy to the traditional syndesmotic screw, but also has advantages of allowing early weightbearing, low requirements for routine removal.

Functional outcome of routine versus on-demand removal of the syndesmotic screw: a multicentre randomized controlled trial

Aims

The aim of this study was to investigate whether on-demand removal (ODR) is noninferior to routine removal (RR) of syndesmotic screws regarding functional outcome.

Methods

Adult patients (aged above 17 years) with traumatic syndesmotic injury, surgically treated within 14 days of trauma using one or two syndesmotic screws, were eligible (n = 490) for inclusion in this randomized controlled noninferiority trial. A total of 197 patients were randomized for either ODR (retaining the syndesmotic screw unless there were complaints warranting removal) or RR (screw removed at eight to 12 weeks after syndesmotic fixation), of whom 152 completed the study. The primary outcome was functional outcome at 12 months after screw placement, measured by the Olerud-Molander Ankle Score (OMAS).

Results

There were 152 patients included in final analysis (RR = 73; ODR = 79). Of these, 59.2% were male (n = 90), and the mean age was 46.9 years (SD 14.6). Median OMAS at 12 months after syndesmotic fixation was 85 (interquartile range (IQR) 60 to 95) for RR and 80 (IQR 65 to 100) for ODR. The noninferiority test indicated that the observed effect size was significantly within the equivalent bounds of -10 and 10 scale points (p < 0.001) for both the intention-to-treat and per-protocol, meaning that ODR was not inferior to RR. There were significantly more complications in the RR group (12/73) than in the ODR group (1/79) (p = 0.007).

Conclusion

ODR of the syndesmotic screw is not inferior to routine removal when it comes to functional outcome. Combined with the high complication rate of screw removal, this offers a strong argument to adopt on demand removal as standard practice of care after syndesmotic screw fixation.

Cite this article: Bone Joint J 2021;103-B(11):1709–1716.

Syndesmotic Ligament Allograft Reconstruction for Treatment of Chronic Diastasis

Chronic diastasis after a syndesmotic injury can lead to ankle joint instability and loss of joint congruence. Failure to restore the fibula into the proper anatomic position within the incisura increases the focal stress on the talus and can accelerate degenerative joint destruction. In the case of failed syndesmotic repair, fixation options are limited. If promptly diagnosed, the syndesmosis may be amenable to open debridement and subsequent fixation with 2 interosseous screws. If latent diastasis is found, however, syndesmotic fusion by bone block arthrodesis is recommended. We present a syndesmotic allograft repair technique for surgical reconstruction of chronic unstable syndesmotic ruptures.

The Role of Deltoid Ligament Repair in Ankle Fractures With Syndesmotic Instability: A Systematic Review

Ankle fractures are the fourth most common fracture requiring surgical management. The deltoid ligament is a primary ankle stabilizer against valgus forces. It is frequently ruptured in ankle fractures; however, there is currently no consensus regarding repair. 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. Screening, quality assessment, and data extraction were performed independently and in duplicate. Data extracted included pain, range of motion (ROM), function, medial clear space (MCS), syndesmotic malreduction, and complications. After screening, 9 eligible studies from 1990 to 2018 were included (N = 508). Compared to nonrepair groups, deltoid ligament repair patients had lower syndesmotic malreduction rates (0%-9% vs 20%-35%, p ≤ .05), fewer implant removals (5.8% vs 41% p ≤ .05), and longer operating time by 16-20 minutes (p ≤ .05). There was no significant difference for pain, function, ROM, MCS, and complication rate (p ≤ .05). In conclusion, deltoid ligament repair offers lower syndesmotic malreduction rates and reduced re-operation rates for hardware removal in comparison to trans-syndesmotic screws. Repair groups demonstrated equivalent or better outcomes for pain, function, ROM, MCS, and complication rates. Other newer syndesmotic fixation methods such as suture-button fixation require further evaluation when compared to the outcomes of deltoid ligament repair. A randomized control trial is required to further examine the outcomes of ankle fracture patients who undergo deltoid ligament repair versus trans-syndesmotic screw fixation.

Surgical Site Infections After Routine Syndesmotic Screw Removal: A Systematic Review

OBJECTIVES

To investigate the incidence of surgical site infections (SSIs) after routine removal of syndesmotic screws (SSs) placed to stabilize syndesmotic injuries.

DATA SOURCES

A systematic literature search was performed in the PubMed, Cochrane, and EMBASE databases for studies published online before February 2020, using the key words and synonyms of "syndesmotic screw" ("ankle fractures" or "syndesmotic injury") and "implant removal."

STUDY SELECTION

Studies were eligible for inclusion when they described >10 adult patients undergoing elective/scheduled removal of the SS.

DATA EXTRACTION

The 15 included articles were assessed for quality and risk of bias using the Newcastle-Ottawa Scale. Baseline characteristics of the studies, the study population, the intervention, the potential confounders, and the primary outcome (% of SSIs) were extracted using a customized extraction sheet.

DATA SYNTHESIS

The primary outcome was presented as a proportion of included patients and as a weighted mean, using inverse variance, calculated in RStudio. Furthermore, potential confounders were identified.

CONCLUSIONS

The percentage of SSIs ranged from 0% to 9.2%, with a weighted mean of 4%. The largest proportion of these infections were superficial (3%, 95% confidence interval: 2-5), compared with 2% deep infections (95% confidence interval: 1-4). These rates were comparable to those of other foot/ankle procedures indicating that the individual indication for SS removal (SSR) should be carefully considered. Future studies should focus on valid indications for SSR, the influence of prophylactic antibiotics on an SSI after SSR, and complications of retaining the SS to enable a fair benefits/risks comparison of routine versus on-demand removal of the SS.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A fibular notch approach for the treatment of ankle fractures involving the distal tibial plafond

Background

Although efficacy is related to many factors, the surgical approach is one of the most important intervention factors for complex ankle fractures. Ankle fractures involving the distal tibial plafond frequently present a surgical challenge in choosing which incisions will be best for surgical treatment. Here, we present an innovative fibular notch approach for the treatment of some specific ankle fractures and present a series of patients with either functional or radiographic outcomes.

Methods

Twenty-two patients with distal tibial plafond fractures with concomitant fibular and distal tibiofibular syndesmosis injuries were treated through a fibular notch approach in this retrospective study. The details of the surgical technique were reviewed from the operative notes. Relevant data were reviewed from the medical records. The quality of fractures and syndesmosis reduction was examined using CT scans, and lateral stability of the ankle was assessed by physical examination and stress radiographs. The American Orthopedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS) score was implemented for clinical functional assessment.

Results

All surgeries were successfully performed via the fibular notch approach as the primary approach with excellent intraoperative visualization. Postoperative radiography revealed satisfying restoration of all fractures and syndesmosis. All fractures healed with an average time of 17.3 ± 3.6 weeks. Mild posttraumatic osteoarthritis (PTOA) was present in 4 patients. The average AOFAS score was 88.8 at the last follow-up.

Conclusions

The fibular notch approach is a safe and reliable approach for the treatment of specific ankle fractures involving the distal tibial plafond. This approach provides excellent direct visualization of the fragments and articular surface without significantly increasing iatrogenic injuries. Satisfactory radiographic and clinical results were observed, and further clinical and anatomical studies are recommended to ascertain the feasibility of this approach in the treatment of complex distal tibial fractures.

Traumatic injuries of the distal tibiofibular syndesmosis

The distal tibiofibular syndesmosis (DTFS) is frequently injured during ankle trauma. The sequelae can be significant, including chronic instability, early osteoarthritis and residual pain. The aim of this study is to summarize the current state knowledge about these injuries by answering four questions. They frequently occur in the context of an ankle sprain (20-40% of cases) or during various types of ankle fractures (20-100% of cases). They cannot be ruled out based solely on fracture type and must be investigated when a fibular or posterior malleolar fracture is present. Clinical examination and imaging are essential but do not provide a definitive diagnosis. Ultrasonography, CT scan and MRI have high sensitivity, but their static nature does not allow a treatment strategy to be defined. Dynamic radiographs must be taken, either with load or during a procedure. If instability is detected, stabilization is the general rule. In fracture cases, reduction is achieved by restoring the length and rotation of the distal fibular fragment, preferably during an open procedure. In sprain cases, reduction is not a problem unless there is ligament interposition. Tibiofibular fixation is done 1.5 to 3cm from the talocrural joint, while ensuring the reduction is perfect. The main complication-non-healing of the syndesmosis-is attributed to poor initial reduction. This or functional discomfort during weight bearing will require removal of the fixation hardware. In most cases, this allows functional recovery and correction of the inadequate reduction. Persistence of instability will require ligament reconstruction or fusion of the syndesmosis. Chronic instability can lead to ankle osteoarthritis. LEVEL OF EVIDENCE: V, expert opinion.

Weightbearing Cone-Beam Computed Tomography of Acute Ankle Syndesmosis Injuries

Syndesmotic injuries are common, but only a subset of these injuries are unstable. A noninvasive tool for identifying instability would aid in the selection of patients for surgery. Weightbearing computed tomography (CT) data have been reported for healthy patients, but there are limited data on unstable syndesmoses. We evaluated the syndesmotic area of arthroscopically proven unstable ankles after acute injury. This is a prospective comparative study of consecutive patients recruited to a weightbearing CT database. Thirty-nine patients were included for analysis with arthroscopically proven unstable syndesmoses and an uninjured contralateral ankle. The syndesmosis area was measured for both ankles, in non-weightbearing and weightbearing positions, and compared. Syndesmosis area of the unstable ankle was significantly greater than the uninjured ankle of the same patient, by a mean of 22.9 ± 10.5 mm². This was a significantly greater difference than that observed with non-weightbearing CT (9.8 ± 10.2 mm², p < .001). Dynamic change in area, from non-weightbearing to weightbearing, of the unstable ankle (13.7% [16.6 ± 9.9 mm²]) was significantly greater than that of the uninjured ankle (3.1% [3.4 ± 6.7 mm²], p < .001). The intraobserver and interobserver correlations were good with intraclass correlation coefficients of 0.983 and 0.970, respectively. Weightbearing CT demonstrated significantly greater diastasis in unstable ankles than did conventional non-weightbearing CT. Syndesmosis area measurement was reliable and reproducible. Dynamic change in area and weightbearing comparison with the contralateral uninjured ankle are 2 parameters that may prove useful in the future for predicting syndesmotic instability.

Syndesmotic Screw Removal in a Clinic Setting Is Safe and Cost-effective

Background. There is no consensus in the literature regarding the necessity of syndesmotic screw removal, but the majority of surgeons prefer screw removal in the operating room. Purpose. The aim of this study is to analyze the safety and cost-effectiveness of syndesmotic screw removal in the clinic. Methods. A retrospective chart review was performed on all acute, traumatic ankle fractures that required syndesmotic stabilization over 5 years at a level 1 trauma center. Radiographs were evaluated for maintenance of syndesmotic reduction. Orthopaedic clinic visits and operating room costs were calculated. Results. Of 269 patients, syndesmotic screws were successfully removed in the clinic in 170 patients and retained in 99 patients. Two superficial infections (1.2%) developed following screw removal. The superficial infection rate was 3.3% (2 of 60) in patients who did not receive antibiotics compared with 0% (0 of 110) in patients who received antibiotics (P = .12). No patient lost syndesmotic reduction after screw removal. Cost savings of $13 829 per patient were achieved by syndesmotic screw removal in the clinic. Conclusion. Our study demonstrates that syndesmotic screw removal in the clinic is safe, does not result in tibiofibular diastasis, is cost-effective, and results in substantial financial savings. Level of Evidence: Level IV.

Treatment of a high-energy transsyndesmotic ankle fracture: A case report of "logsplitter injury"

INTRODUCTION

The "logsplitter injury" is a special type of ankle fractures that results from high energy violence with combined rotational forces and axial loads. So far, the diagnose and treatment of "logsplitter injury" remain largely unsettled and related literature is rare.

PATIENT CONCERNS

An 18-year-old male fell from a fence and got his left ankle injured with severe malformation and swollen condition. No open wound was observed.

DIAGNOSIS

Logsplitter injury, ankle fracture (AO/OTA classification 44C1.1, Lauge-Hansen classification: pronation-external rotation).

INTERVENTIONS AND OUTCOMES

The patient was initially treated by internal fixation of fibular, repair of deltoid ligaments, and 1 syndesmotic screw fixation. When the X-ray applied after surgery, another 2 syndesmotic screws were performed to enhance stability. The syndesmotic screws were removed at 12-week and 16-week respectively. The patient was allowed for full weight-bearing immediately. However, the syndesmotic space was slightly increased compared to the contralateral side in CT views at 1-year follow-up, the function outcome was satisfied.

CONCLUSION

The logsplitter injury is a high-energy ankle fracture that requires both axial and rotational load. It is categorized as 44B or 44C by the AO/OTA classification. In the classification scheme of Lauge-Hansen, our case is in line with the pronation-external rotation classification. Anatomic reduction and fixation of ankle syndesmotic injuries are required to restore the biomechanics of the ankle joint so that long-term complications can be prevented. How to fixation the syndesmosis, whether to reconstruct the deltoid ligament remains in debate in the treatment of logsplitter injury, whether and when to remove the syndesmotic screws were still debated. Correct surgical intervention is successful in the treatment of "logsplitter injury", however, the optimal fixation of syndesmosis and repair of deltoid ligaments need further investigate.

Prospective Patient Reported Outcomes (PRO) Study Assessing Outcomes of Surgically Managed Ankle Fractures

BACKGROUND

Ankle fractures are a common cause of morbidity that have increased in incidence over the past decade. The purpose of this study was to compare the outcomes and prognosis of various fracture subtypes by using 2 validated patient-reported outcome measures: the Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) Computer Adaptive Tests (CATs).

METHODS

Twelve-month postoperative PF and PI CATs were collected for 126 ankle fracture patients presenting between 2014 and 2017. Patients were stratified by ankle fracture subtype and refined by the presence/absence of concomitant deltoid injury or posterior malleolar fracture. Patients defined as members of vulnerable populations and patients presenting more than 2 weeks from time of injury or with prior acute ipsilateral fracture were excluded. The distribution of PF and PI T scores were assessed via a Shapiro-Wilk test and a 1-way analysis of variance. If significant differences were found between groups, pairwise comparisons were tested via Dwass, Steel, and Critchlow-Fligner multiple comparison analysis.

RESULTS

Mean values for the PROMIS PF and PI for each fracture subtype were calculated and compared to reference population mean (SD) T scores of 50 (10): isolated lateral malleolar (PF: 50/PI: 51), isolated medial malleolar (PF: 52/PI: 49), bimalleolar (PF: 48/PI: 50), trimalleoar (PF: 47/PI: 51), isolated posterior malleolar (PF: 53/PI: 44), and isolated syndesmotic injury (PF: 60/PI: 46). Shapiro-Wilk test indicated a nonnormal distribution for the postoperative PROMIS PF T scores across all fracture patients (P = .0421).

CONCLUSION

Operative fixation of an ankle fracture was able to return most patients to the population mean with regard to PROMIS function and pain regardless of fracture type.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Functional Outcomes of Isolated Infrasyndesmotic Fibula Fractures

Background:

Ankle fractures are among the most common injuries encountered by orthopedic surgeons, with an incidence ranging from 71 to 187 per 100 000 people. Few studies have reliably investigated injuries involving isolated fractures of the distal fibula below the level of the ankle syndesmosis. Therefore, this study details on the patient-reported outcomes of nonoperatively managed isolated infrasyndesmotic fibula (ISF) fractures with a minimum 3-year follow-up.

Methods:

A retrospective population-based cohort study was undertaken across all emergency departments serving a major urban population. Among 159 consecutive patients meeting inclusion criteria, 108 agreed to participate. Clinical information, functional outcomes, and radiographic measurements were collected from electronic medical records and 3 validated outcome measures: the American Academy of Orthopaedic Surgeons (AAOS) Foot & Ankle Scale (FAS), the AAOS Shoe-Comfort Scale (SCS), and a general questionnaire.

Results:

An incidence of 22 ISF fractures per 100 000 people/year was found with FAS (91.2 ± 12.9) and SCS scores (76.8 ± 27.7), similar to reported population norms. Approximately 40% of patients (n = 43) reported continuing symptoms including pain (81.8%), stiffness (68.1%), and/or instability (39.0%). Less than 13% (n = 14) reported “severe” disabilities, and no patients required operative intervention within the follow-up period. Less-favorable outcomes were reported among work-related injuries, female patients, and “avulsion-type” fractures less than 10 mm in height (P < .01). No relationships were identified between age, degree of articular-incongruity, fracture-displacement, and self-reported outcomes.

Conclusions:

The majority of patients with nonoperatively managed ISF fractures reported good-to-excellent early functional outcomes. Less-favorable outcomes were reported among work-related injuries, female patients, and “avulsion-type” fractures.

Level of Evidence:

Level III, comparative series.

Does fracture obliquity in Weber B fibula fractures correlate with mortise instability?

BACKGROUND

The diagnosis of instability in the apparent, isolated distal fibula fracture can be challenging and often necessitates stress radiography. Danis & Weber classified lateral malleolar fractures based on the level of the fracture in relation to the syndesmosis. While Weber B fractures occur at the level of the syndesmosis, some such injuries present with a long, oblique pattern extending well above the syndesmosis. Given the well-established literature demonstrating that fractures above the syndesmosis correlate with a higher level of concomitant syndesmotic and deltoid ligament injury, we hypothesize that increased fracture obliquity, length and height of Weber B fibula fractures similarly correlates with increased mortise instability.

METHODS

All patients with isolated Weber B fibula fractures who underwent gravity stress radiography met inclusion criteria. Fracture height was measured on mortise radiographs as: (1) the distance from the distal tip of the fibula to fracture apex, (2) the distance to the fracture apex as measured on a line drawn perpendicular to a line parallel to the plafond, (3) an angle subtended by a line drawn parallel to the plafond and a line drawn to the fracture apex and (4) a ratio of the absolute length as compared to fibular width.

RESULTS

51 patients were included in the study. The group of 39 patients with stable ankles had a mean medial clear space of 3.12 ± 0.65 mm (range, 1.5 mm to 4.0 mm). The group of 12 patients with unstable ankles had a mean medial clear space of 6.29 ± 3.11 mm (range, 4.1 mm to 14.0 mm). These groups showed no significant difference in fracture angle (p = 0.93), fracture height from plafond (p = 0.49), fracture height from tip of fibula (p = 0.42), and as a ratio of absolute length to fibular width (p = 0.85).

CONCLUSION

Increased fracture obliquity, length and height of Weber B fibula fractures did not correlate with a higher incidence of mortise instability. Despite the lack of positive correlation, future studies should continue to investigate and identify radiographic parameters of distal fibula fractures that are most predictive of instability.

Syndesmotic Ligaments of the Ankle: Anatomy, Multimodality Imaging, and Patterns of Injury

Injuries to the syndesmotic ligaments of the ankle or "high ankle sprains" are common in acute ankle trauma but can be difficult to diagnose both clinically and on imaging. Missed injuries to the syndesmosis can lead to chronic ankle instability, which can cause persistent pain and lead to early osteoarthritis. This review will illustrate the anatomy of the syndesmotic ligamentous complex, describe radiographic, CT, and MR imaging of the syndesmosis, demonstrate typical mechanisms of injuries and associated fracture patterns, and provide an overview of important management considerations.

Diagnosis and treatment of ankle syndesmosis injuries with associated interosseous membrane injury: a current concept review

BACKGROUND

Tibiofibular syndesmosis injury leads to ankle pain and dysfunction when ankle injuries are not treated properly. Despite several studies having been performed, many questions about diagnosis and treatment remain unanswered, especially in ankle syndesmosis injury with interosseous membrane injury. Therefore, the purpose of this study was to help guide best practice recommendations.

METHODS

This review explores the mechanism of injury, clinical features, diagnosis methods, and the treatment strategy for ankle syndesmosis injury with interosseous membrane injury to highlight the current evidence in terms of the controversies surrounding the management of these injuries.

RESULTS

Radiological and CT examination are an important basis for diagnosing ankle syndesmosis injury. Physical examination combined with MRI to determine the damage to the interosseous membrane is significant in guiding the treatment of ankle syndesmosis injury with interosseous membrane injury. In the past, inserting syndesmosis screws was the gold standard for treating ankle syndesmosis injury. However, there were increasingly more controversies regarding loss of reduction and broken nails, so elastic fixation has become more popular in recent years.

CONCLUSIONS

Anatomical reduction and effective fixation are the main aspects to be considered in the treatment of ankle syndesmosis injury with interosseous membrane injury and are the key to reducing postsurgery complications.

Computed Tomography Analysis for Quantification of Displacement of the Distal Fibula in Different Foot Positions With Weightbearing and Sequentially Increased Instability: An Anatomic Cadaveric Study on Syndesmosis

Syndesmotic injuries are quite common, but accurate diagnosis and treatment can be difficult, in part because of individual anatomic variation and complex movements of the fibula in the incisura. The current cadaveric study was designed to investigate changes in the position of the fibula in the incisura during simulated weightbearing in different foot positions and with sequential sectioning of syndesmotic and deltoid ligaments. Sixteen paired, fresh-frozen cadaveric limbs were embedded in polymethylmethacrylate mid-calf and placed in a weightbearing simulation frame. Computed tomography scans were obtained while the legs were in a simulated foot-flat position (75 N) and single-leg stance (700 N) in 5 foot positions: neutral, 15° external rotation, 15° internal rotation, 20° dorsiflexion, and 20° plantar flexion. The anterior-inferior tibiofibular ligament, posterior tibiofibular ligament complex, deltoid, and interosseous membranes were sectioned sequentially and rescanned. Measurements of fibular diastasis, rotation, anterior-posterior and medial-lateral translation, and fibular shortening were performed. The most destructive state resulted in the largest displacement at the syndesmosis. The degree of subluxation in all ligament states was dependent on the foot position. External rotation created statistically significant displacement at all levels of injury. There were no significant differences between sides of the same donor. Our data demonstrate the importance of foot position in reduction at the syndesmosis under weightbearing. The current ex vivo model could be used to evaluate other aspects of this injury or the value of reconstructive techniques in the future.

Syndesmosis and Syndesmotic Equivalent Injuries in Tibial Plafond Fractures

OBJECTIVES

To identify the incidence and fracture characteristics associated with syndesmotic injury in tibial plafond fractures and report the incidence of posttraumatic osteoarthrosis (PTOA).

DESIGN

Retrospective comparative study.

SETTING

Two level-1 academic trauma centers.

PATIENTS/PARTICIPANTS

Of the 735 tibial plafond fractures (OTA/AO 43-B3 and 43-C) treated from January 2006 through December 2015, 108 patients (108/735, 15%) were identified with syndesmosis injury.

INTERVENTION

Either acute or missed syndesmotic injury.

MAIN OUTCOME MEASUREMENT

PTOA.

RESULTS

Fourteen fractures (14/735, 2%) had missed syndesmotic injury. Volkmann fragment of ≤10 mm (P = 0.04) and fibular avulsion fracture (P = 0.05) were significantly more common in missed syndesmosis. Ninety fractures (14/14 missed, 76/94 acute) had greater than 12-month follow-up (mean, 26 months; range, 12-102 months). Nearly all patients with missed syndesmosis injury developed arthrosis (13/14, 93%), and 45% (34/76 fractures) of plafond fractures with acute syndesmosis injury developed arthrosis (P < 0.001). Although controlling for malreduction, patients with missed syndesmosis had significantly more PTOA development (P = 0.018). Controlling for malreduction, patients with syndesmotic fixation and a ≤10-mm Chaput or Volkmann fragment or fibular avulsion fracture (8/31, 26%) were less likely to develop PTOA than if they had a similar fracture pattern without syndesmotic fixation (9/10, 90%) (P = 0.011).

CONCLUSIONS

Fifteen percent of tibia plafond fractures have a syndesmosis or syndesmotic equivalent injury. Missed syndesmosis injury has a high rate of PTOA development. Patients with a ≤10-mm Chaput or Volkmann fragment and/or fibular avulsion fracture benefit from syndesmotic fixation.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Arthroscopic Grading of Injuries of the Inferior Tibiofibular Syndesmosis

The objective of this study was to describe the technical details of performing a newly developed arthroscopic grading of inferior tibiofibular syndesmosis injuries. Arthroscopy is emerging as the gold standard for evaluating painful, unstable ankles. The inferior tibiofibular syndesmosis contributes substantially to disorders of the ankle. However, no structured grading system exists that would help surgeons evaluate injuries of the syndesmosis. Seventy-eight patients with pain or instability symptoms in the ankle were arthroscopically evaluated for syndesmosis injury. The lesions were graded according to the prospectively developed protocol. More than 61% of the patients had syndesmosis disruptions of various grades affecting the anterior/posterior ligaments or both ligaments. Fourteen patients had anterior ligament disruptions whereas 4 patients had posterior lesions; another 7 patients had both ligaments asymmetrically injured. Eighteen of the 78 patients had symmetric grade 1 lesions, and 5 had grade 2 lesions. More than half of chronic ankle pain cases have syndesmotic lesions. Symmetrical lesions of the anterior and posterior ligaments predominate, followed by isolated anterior ligament disruptions. The proposed grading system for inferior tibiofibular syndesmosis disruptions serves as a guide to systematic documentation of injuries of the syndesmosis.

Assessing Quality of Syndesmotic Reduction in Surgically Treated Acute Syndesmotic Injuries: A Systematic Review

There is no universal method with cutoff values for the assessment of distal tibiofibular joint reduction in acute syndesmotic injuries. It is important to detect malreductions because they may lead to impaired functional outcome and may demand reoperations. The aim of this study was to systematically review the literature to evaluate the appropriateness of different image techniques in determining syndesmotic malalignment. A literature search was conducted in Medline, Embase, and the Cochrane Library to search for articles assessing syndesmotic reduction. Excluded were articles where no criteria and/or measurements for syndesmotic reduction were provided, only normative values were provided and reviews. In total, 2157 articles were found, of which 1421 studies were screened for title and abstract after exclusion of duplicates. One hundred ten studies were eligible for full-text analysis. Of these, 61 were excluded. Three studies where added after screening the included references. Fifty-two studies were included, of which 32 were original publications and 20 were publications referring to the original publications. From the original publications, 14 used plains radiographs, 19 computed tomographic (CT) scans, and 5 used 3-dimensional CT scans (some authors used >1 modality in their study). For each modality, a large number of parameters and different cutoff values were reported. CT scanning is superior to plain radiography in the assessment of the quality of joint reduction. Parameters used the most were fibular position in the incisura and fibular rotation. The criteria for adequate reduction should at least include the position of the fibula in the incisura and rotation of the fibula, while ensuring adequate fibular length, all equaling or at least approaching the values of the uninjured contralateral side.

Anterior inferior tibiofibular ligament avulsion fractures in operatively treated ankle fractures: a retrospective analysis

BACKGROUND

There is no consensus about the optimal treatment of anterior inferior ligament avulsion fractures of the ankle. The aim of this study is to provide insights regarding the incidence of anterior inferior ligament avulsion fractures, the association with fracture type, and correlation with treatment.

METHODS

This study is a retrospective analysis in a level-1 trauma center of adult patients with an ankle fracture operated between the dates 01-01-2009 and 01-09-2017 who had a pre- and postoperative CT-scan. Within the study population, the incidence of AITFL avulsion fracture was defined. Primary outcome was the type of avulsion fracture and related treatment. Secondary outcome was additional surgery in relation to the initial treatment.

RESULTS

In total, 65 of 252 (25.8%) patients were diagnosed with an anterior inferior ligament avulsion fracture. Zero patients had a Wagstaffe type 1 fracture, 28 (43.1%) had a type 2, 32 (49.2%) had a type 3, and 5 (7.7%) had a type 4. There was a correlation between Wagstaffe type 2 and Weber B fractures, p < 0.0001, and Wagstaffe type 3 avulsions were correlated with a Weber C fracture, p < 0.0001. Thirty-five of the avulsed fragments (53.8%) were smaller than 5 mm. In 13 (20%) of patients with anterior inferior ligament avulsion fracture, the avulsed fragments were directly fixated during initial surgery. Size and direct fixation of the fragment were significantly correlated (p < 0.0001). Within the anterior inferior ligament avulsion fracture group, only a total of four patients (6.2%) underwent a revision.

CONCLUSION

In the current study, an incidence of 25.8% of anterior inferior ligament avulsion fracture in surgically treated ankle fractures is reported. A correlation between the type of Wagstaffe injury and Weber classification was showed. Most fragments smaller than 5 mm were not fixated; however, not all injuries needed syndesmotic screws due to syndesmotic instability.

LEVEL OF EVIDENCE

Level IV.

The management of syndesmotic screw in ankle fractures

BACKGROUND AND AIM

There is a wide debate about the number, diameter and length of the syndesmotic screw and necessity and timing for its removal. The aim of this study is to determine whether functional and radiological outcomes differ in patients operated for Weber type B and C ankle fractures who had syndesmotic screws removed (group 1) compared to those who did not (group 2). Furthermore, authors want to define if it is really necessary to remove this device and its correct timing.

MATERIALS AND METHODS

90 patients were eligible for the study. The functional outcomes were analyzed 1 year after surgery using OMAS and AOFAS scores. Radiographic evaluation assessed the tibiofibular distance immediately and 12 months after surgery and fracture's healing.

RESULTS

Clinical and x-rays results were similar in both groups at follow-up.

DISCUSSION

Fractures with interruption of syndesmosis are lesions that, if not well treated, are complicated by joint stiffness, residual pain and post-traumatic osteoarthritis. Syndesmotic screw removal is not routinely performed, thus accepting the risk of rupture but avoiding a new surgery.

CONCLUSIONS

Results observed suggest that syndesmotic screw removal is not necessary. If surgeon decide to remove this device correct timing is mandatory in order to obtain satisfactory long-term results.

The application of intraoperative ankle dislocation approach in the treatment of the unstable trimalleolar fractures involving posterior ankle comminuted fracture: a retrospective cohort study

Background

The aim of this study was to introduce a novel intraoperative lateral ankle dislocation approach during surgical treatment for patients with unstable trimalleolar fractures involving posterior ankle comminuted fractures and compare its effects and safety with those with conventional approach.

Methods

From June 2006 to June 2014, 69 patients diagnosed as unstable trimalleolar fractures involving posterior ankle comminuted fracture were included in this study. The patients were divided into intraoperative dislocating ankle group (experimental group) and conventional treatment group (control group) according to surgical modalities. The following parameters including rate of primary healing, healing time, incidence of talus necrosis, incidence of post-traumatic arthritis, functional outcomes according to Baird-Jackson classification system, and any possible complications in two groups were recorded and compared.

Results

There were no significant differences regarding the rate of primary healing, healing time and the rate of talus necrosis in two groups (P > 0.05). The incidence of post-traumatic arthritis in experimental and control group were 0 and 24.24% (P = 0.0006), respectively. The rate of excellent and good outcomes were achieved in 91.67% in experimental group and 72.73% in control group (P = 0.038), respectively.

Conclusions

The findings suggest that the intraoperative ankle dislocation approach appears to be a promising surgical option for unstable trimalleolar fractures involving posterior ankle comminuted fracture because it can provide better functional outcomes and lower incidence of post-traumatic arthritis while not compromising primary healing and healing time.

A novel method of using elastic bionic fixation device for distal tibiofibular syndesmosis injury

PURPOSE

To describe and evaluate the novel method of using elastic bionic fixation device in treating the distal tibiofibular syndesmosis (DTS) injury.

METHODS

From June 2013 to January 2014, 17 subjects with ankle fractures combined with DTS separation were treated by the elastic bionic fixation device. The syndesmotic parameters, healing, functional scores, and possible complications were recorded.

RESULTS

All patients had a mean follow-up of 23.35 ± 4.39 months (range, 15-28 months). Syndesmotic parameters returned to normal after surgery and remained normal throughout the follow-up period. X-ray examinations at 12 months follow-up showed no cable breakage of the elastic bionic fixation device or instrument invalidation compared to that of immediate post-operative X-ray films. Besides, no signs of articular degeneration and arthritis were observed. Furthermore, change in bone density near the fibular fixing button or tibial screw nut was also not detected. Primary wound healing was observed in 16 patients, while the remaining one showed redness and swelling of lateral ankle incision and got wound healing after seven to ten  days of antibiotic therapy and local radio frequency physiotherapy. All obtained excellent and good outcomes according to the AOFAS score at 12 months after surgery.

CONCLUSIONS

The use of elastic bionic fixation device appears to be a promising option in treating DTS injury because it can provide stable and reliable elastic fixation, good functional recovery, and relatively fewer complications.

Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial)

BACKGROUND

Syndesmotic injuries are common and their incidence is rising. In case of surgical fixation of the syndesmosis a metal syndesmotic screw is used most often. It is however unclear whether this screw needs to be removed routinely after the syndesmosis has healed. Traditionally the screw is removed after six to 12 weeks as it is thought to hamper ankle functional and to be a source of pain. Some studies however suggest this is only the case in a minority of patients. We therefore aim to investigate the effect of retaining the syndesmotic screw on functional outcome.

DESIGN

This is a pragmatic international multicentre randomised controlled trial in patients with an acute syndesmotic injury for which a metallic syndesmotic screw was placed. Patients will be randomised to either routine removal of the syndesmotic screw or removal on demand. Primary outcome is functional recovery at 12 months measured with the Olerud-Molander Score. Secondary outcomes are quality of life, pain and costs. In total 194 patients will be needed to demonstrate non-inferiority between the two interventions at 80% power and a significance level of 0.025 including 15% loss to follow-up.

DISCUSSION

If removal on demand of the syndesmotic screw is non-inferior to routine removal in terms of functional outcome, this will offer a strong argument to adopt this as standard practice of care. This means that patients will not have to undergo a secondary procedure, leading to less complications and subsequent lower costs.

TRIAL REGISTRATION

This study was registered at the Netherlands Trial Register (NTR5965), Clinicaltrials.gov ( NCT02896998 ) on July 15th 2016.

A New Intraoperative Syndesmosis Instability Classification System: Utility and Medium-term Results in Closed Displaced Ankle Fractures

OBJECTIVE

To investigate the utility and medium-term results of a new intra-operative classification system for distal tibiofibular syndesmosis injury in ankle fractures.

METHODS

Between January 2010 and January 2015, 116 patients diagnosed with displaced closed Weber B and C ankle fractures were treated in our department. The etiology of injury was 56 cases of fall-sprain, 36 of traffic injury, 14 of fall from a height, and 10 of multiple injuries. After fixation of the fibular fracture, we classify syndesmosis stability as either normal or one of three grades of instability using the fibular hook traction test. This determined further fixation selection and final syndesmosis treatment.

RESULTS

Of 116 cases, 82 (71%) demonstrated a tibiofibular syndesmosis injury and 52 (45%) were unstable. Twenty-six cases were type I injuries (<4 mm displacement), 41% cases were type II injuries (4-7 mm displacement), and 3% of cases were type III injuries (>7 mm displacement). Types II and III are defined as unstable and require stabilization. Type III injuries have multiplanar instability and require two screws at the syndesmosis. Weber C fractures demonstrate significantly greater degrees of instability than Weber B fractures (χ² = 15.50, P = 0.0014). All patients were followed up for 12-24 months, with no cases of non-union or broken screws. Good and excellent results were achieved in 93% of cases (according to the American Orthopaedic Foot and Ankle Society scoring system).

CONCLUSION

The syndesmosis instability classification system provides a rational and efficient basis for managing syndesmosis instability. Our results from application of the algorithm justify its further evaluation in the treatment of patients with closed displaced Weber B and C ankle fractures.

Acute syndesmotic instability in ankle fractures: A review

Ankle fractures are among the most common fracture types, and 10% of all ankle fractures lead to accessory syndesmotic injury. An injury that is challenging in every respect is syndesmotic instability. Since the range of diagnostic techniques and the therapeutic options is extensive, it still is a controversial subject, despite the abundance of literature. This review aimed to summarize the current knowledge on syndesmotic instability in ankle fractures and to formulate some recommendations for clinical practice. Chronic instability and the operative osseous treatment of ankle fractures are not part of this review.

Distal Tibiofibular Syndesmosis: Anatomy, Biomechanics, Injury and Management

A stable and precise articulation of the distal tibiofibular syndesmosis is essential for normal motion of the ankle joint. Injury to the syndesmosis occurs through rupture or bony avulsion of the syndesmotic ligament complex. External rotation of the talus has been identified as the major mechanism of syndesmotic injury. None of the syndesmotic stress tests was sensitive or specific; therefore the diagnosis of syndesmotic injury should not be made based on the medical history and physical examination alone. With the improvement in ankle arthroscopic technique, it can be used as a diagnostic and therapeutic tool in the management of distal tibiofibular syndesmosis injury.

Overtightening of the syndesmosis revisited and the effect of syndesmotic malreduction on ankle dorsiflexion

BACKGROUND

Ankle syndesmotic injuries are a significant source of morbidity and require anatomic reduction to optimize outcomes. Although a previous study concluded that maximal dorsiflexion during syndesmotic fixation was not required, methodologic weaknesses existed and several studies have demonstrated improved ankle dorsiflexion after removal of syndesmotic screws. The purposes of the current investigation are: (1) To assess the effect of compressive syndesmotic screw fixation on ankle dorsiflexion utilizing a controlled load and instrumentation allowing for precise measurement of motion. (2) To assess the effect of anterior & posterior syndesmotic malreduction after compressive syndesmotic screw fixation on ankle dorsiflexion.

MATERIAL AND METHODS

Fifteen lower limb cadaveric leg specimens were utilized for the study. Ankle dorsiflexion was measured utilizing a precise micro-sensor system after application of a consistent load in the (1) intact state, (2) after compression fixation with a syndesmotic screw and (3) after anterior & (4) posterior malreduction of the syndesmosis.

RESULTS

Following screw compression of the nondisplaced syndesmosis, dorsiflexion ROM was 99.7±0.87% (mean±standard error) of baseline ankle ROM. Anterior and posterior malreduction of the syndesmosis resulted in dorsiflexion ROM that was 99.1±1.75% and 98.6±1.56% of baseline ankle ROM, respectively. One-way ANOVA was performed showing no statistical significance between groups (p-value=0.88). Two-way ANOVA comparing the groups with respect to both the reduction condition (intact, anatomic reduction, anterior displacement, posterior displacement) and the displacement order (anterior first, posterior first) did not demonstrate a statistically significant effect (p-value=0.99).

CONCLUSION

Maximal dorsiflexion of the ankle is not required prior to syndesmotic fixation as no loss of motion was seen with compressive fixation in our cadaver model. Anterior or posterior syndesmotic malreduction following syndesmotic screw fixation had no effect on ankle dorsiflexion. Poor patient outcomes after syndesmotic malreduction may be due to other factors and not loss of dorsiflexion motion.

LEVEL OF EVIDENCE

IV.

Treatment of Medial Malleolus or Pure Deltoid Ligament Injury in Patients with Supination-External Rotation Type IV Ankle Fractures

OBJECTIVE

To investigate the effect of internal fixation on postoperative ankle function in patients with supination-external rotation type IV ankle fractures, including medial malleolus fractures and deltoid ligament injury.

METHODS

Between January 2012 and June 2014, patients with medial structure injuries were enrolled in this study and assigned to the medial malleolus fracture group or the deltoid ligament group. The surgical procedures for the two groups were documented. The follow-up endpoint was the time point when the steel plate or screw was removed from the lateral ankle. The Olerud-Molander ankle scoring system was used to assess ankle function.

RESULTS

A total of 84 patients with supination-external rotation type IV ankle fractures had complete medical records and were included in this study. The average age of the patients was 44.16 years (range, 15-75). The patient sample included 39 males and 45 females. Overall, 49 patients (19 males and 30 females) suffered a medial malleolus fracture. The average age of these patients was 40.20 years (range, 15-75). Patients with a posterior malleolar fracture fragment >25% of the articular surface accounted for 81.6% (40 patients) of these patients. Overall, 35 patients (20 males and 15 females) experienced a deltoid ligament injury. The average age of these patients was 44.21 years (range, 17-73). Patients with a posterior malleolar fracture fragment >25% of the articular surface accounted for 11.5% (four patients) of these patients. Open reduction was performed in patients with medial malleolus fractures, and two 4.0-mm cannulated screws were used to fixate the posterior malleolus and the medial malleolus. The suture-anchor technique was used to repair the ligaments in patients with deltoid ligament injuries. The follow-up endpoint was the time point when the steel plate and screws were removed from the lateral ankle in patients. The average follow-up period was 13.4 months (range, 11-17). The Olerud-Molander ankle scoring system was used to assess postoperative ankle function. The average score for the patients in the medial malleolus fracture group was 90.3 points (range, 85-95). The average score for the patients in the deltoid ligament injury group was 87.7 points (range, 80-95). No significant differences were found in the scores between the two groups.

CONCLUSION

Medial malleolus fracture and deltoid ligament injury are two different presentations of supination-external rotation type IV ankle fractures. Anatomic reduction of the articular surface concurrent with restoration of ankle stability can achieve favorable results for these two injuries.

Should syndesmotic screws be removed after surgical fixation of unstable ankle fractures? a systematic review

AIMS

In approximately 20% of patients with ankle fractures, there is an concomitant injury to the syndesmosis which requires stabilisation, usually with one or more syndesmotic screws. The aim of this review is to evaluate whether removal of the syndesmotic screw is required in order for the patient to obtain optimal functional recovery.

MATERIALS AND METHODS

A literature search was conducted in Medline, Embase and the Cochrane Library for articles in which the syndesmotic screw was retained. Articles describing both removal and retaining of syndesmotic screws were included. Excluded were biomechanical studies, studies not providing patient related outcome measures, case reports, studies on skeletally immature patients and reviews. No restrictions regarding year of publication and language were applied.

RESULTS

A total of 329 studies were identified, of which nine were of interest, and another two articles were added after screening the references. In all, two randomised controlled trials (RCT) and nine case-control series were found. The two RCTs found no difference in functional outcome between routine removal and retaining the syndesmotic screw. All but one of the case-control series found equal or better outcomes when the syndesmotic screw was retained. However, all included studies had substantial methodological flaws.

CONCLUSIONS

The currently available literature does not support routine elective removal of syndesmotic screws. However, the literature is of insufficient quality to be able to draw definitive conclusions. Secondary procedures incur a provider and institutional cost and expose the patient to the risk of complications. Therefore, in the absence of high quality evidence there appears to be little justification for routine removal of syndesmotic screws. Cite this article: Bone Joint J 2016;98-B:1497-1504.

Management of syndesmotic injuries: What is the evidence?

Ankle fractures are accompanied by a syndesmotic injury in about 10% of operatively treated ankle fractures. Usually, the total rupture of the syndesmotic ligaments with an external rotation force is associated with a Weber type B or C fracture or a Maisonneuve fracture. The clinical assessment should consist of a comprehensive history including mechanism of injury followed by a specific physical examination. Radiographs, and if in doubt magnetic resonance imaging, are needed to ascertain the syndesmotic injury. In the case of operative treatment the method of fixation, the height and number of screws and the need for hardware removal are still under discussion. Furthermore, intraoperative assessment of the accuracy of reduction of the fibula in the incisura using fluoroscopy is difficult. A possible solution might be the assessment with intraoperative three-dimensional imaging. The aim of this article is to provide a current concepts review of the clinical presentation, diagnosis and treatment of syndesmotic injuries.

Effects of inferior tibiofibular syndesmosis injury and screw stabilization on motion of the ankle: a finite element study

PURPOSE

Traditional studies of syndesmosis injury and screw stabilization have been conducted in cadaveric models, which cannot yield sufficient and exact biomechanical data about the interior of the ankle. The purpose of this study was to evaluate the effects of inferior tibiofibular syndesmosis injury (ITSI) and screw stabilization on the motion of the ankle with finite element analysis.

METHODS

Three-dimensional models of the ankle complex were created with CT images of a volunteer's right ankle in three states: normal, post-ITSI, and stabilization with a screw 2.5 cm above (parallel to) the ankle. Simulated loads were applied under three conditions: neutral position with single foot standing, internal rotation, and external rotation of the ankle.

RESULTS

Compared with the normal state, ITSI increased the relative displacement between the lower extremes of the tibia and fibula in the anteroposterior and mediolateral directions and the angular motion of the tibia, fibula, and talus at internal and external rotations (ERs). However, when stabilized with syndesmotic screws, the range of motion (ROM) and all these parameters significantly decreased.

CONCLUSION

ITSI can lead to internal and ER instability of the ankle joint. Screw stabilization is effective in controlling the instability, but may reduce markedly the ROM of the ankle joint. Through this study, it can be proposed that the screws should be removed once the healing is gained in order to restore normal function of the ankle joint as soon as possible.

Long-term functional and radiographic outcomes in 243 operated ankle fractures

BACKGROUND

Large comparative studies that have evaluated long-term functional outcome of operatively treated ankle fractures are lacking. This study was performed to analyse the influence of several combinations of malleolar fractures on long-term functional outcome and development of osteoarthritis.

METHODS

Retrospective cohort-study on operated (1995-2007) malleolar fractures. Results were assessed with use of the AAOS- and AOFAS-questionnaires, VAS-pain score, dorsiflexion restriction (range of motion) and osteoarthritis. Categorisation was determined using the number of malleoli involved.

RESULTS

243 participants with a mean follow-up of 9.6 years were included. Significant differences for all outcomes were found between unimalleolar (isolated fibular) and bimalleolar (a combination of fibular and medial) fractures (AOFAS 97 vs 91, p = 0.035; AAOS 97 vs 90, p = 0.026; dorsiflexion restriction 2.8° vs 6.7°, p = 0.003). Outcomes after fibular fractures with an additional posterior fragment were similar to isolated fibular fractures. However, significant differences were found between unimalleolar and trimalleolar (a combination of lateral, medial and posterior) fractures (AOFAS 97 vs 88, p < 0.001; AAOS 97 vs 90, p = 0.003; VAS-pain 1.1 vs 2.3 p < 0.001; dorsiflexion restriction 2.9° vs 6.9°, p < 0.001). There was no significant difference in isolated fibular fractures with or without additional deltoid ligament injury. In addition, no functional differences were found between bimalleolar and trimalleolar fractures. Surprisingly, poor outcomes were found for isolated medial malleolar fractures. Development of osteoarthritis occurred mainly in trimalleolar fractures with a posterior fragment larger than 5 %.

CONCLUSIONS

The results of our study show that long-term functional outcome is strongly associated to medial malleolar fractures, isolated or as part of bi- or trimalleolar fractures. More cases of osteoarthritis are found in trimalleolar fractures.