We report on the first clinical cases of the Arthrex Ankle
Nearly one quarter of ankle fractures have a recognized syndesmosis injury. An intact syndesmosis ligament complex stabilizes the distal tibio-fibular joint while allowing small, physiologic amounts of relative motion. When injured, malreduction of the syndesmosis has been found to be the most important independent factor that contributes to inferior functional outcomes. Despite this, significant variability in surgical treatment remains. This may be due to a poor understanding of normal dynamic syndesmosis motion and the resultant impact of static and dynamic fixation on post-injury syndesmosis kinematics. As the syndesmosis is a dynamic structure, conventional CT static images do not provide a complete picture of syndesmosis position, giving potentially misleading results. Dynamic CT technology has the ability to image joints in real time, as they are moved through a range-of-motion (ROM). The aim of this study was to determine if syndesmosis position changes significantly throughout ankle range of motion, thus warranting further investigation with dynamic CT. This is an a priori planned subgroup analysis of a larger multicentre randomized clinical trial, in which patients with AO-OTA 44-C injuries were randomized to either Tightrope or screw fixation. Bilateral ankle CT scans were performed at 1 year post-injury, while patients moved from maximal dorsiflexion (DF) to maximal plantar flexion (PF). In the uninjured ankles, three measurements were taken at one cm proximal to the ankle joint line in maximal DF and maximal PF: Anterior (ASD), middle (MSD), and posterior (PSD) syndesmosis distance, in order to determine normal syndesmosis position. Paired samples t-tests compared measurements taken at maximal DF and maximal PF. Twelve patients (eight male, six female) were included, with a mean age of 44 years (±13years). The mean maximal DF achieved was 1-degree (± 7-degrees), whereas the mean maximal PF was 47-degrees (± 8-degrees). The ASD in DF was 3.0mm (± 1.1mm) versus 1.9mm (± 0.8mm) in PF (p<0.01). The MSD in DF was 3.3mm (±1.1mm) versus 2.3mm (±0.9mm) in PF (p<0.01). The PSD in DF was 5.3mm (±1.5mm) versus 4.6mm (±1.9mm) in PF (p<0.01). These values are consistent with the range of normal parameters previously reported in the literature, however this is the first study to report the ankle position at which these measurements are acquired and that there is a significant change in syndesmosis measurements based on ankle position. Normal syndesmosis position changes in uninjured ankles significantly throughout range of motion. This motion may contribute to the variation in normal anatomy previously reported and controversies surrounding quantifying anatomic reduction after injury, as the ankle position is not routinely standardized, but rather static measurements are taken at patient-selected ankle positions. Dynamic CT is a promising modality to quantify normal ankle kinematics, in order to better understand normal syndesmosis motion. This information will help optimize assessment of reduction methods and potentially improve patient outcomes. Future directions include side-to-side comparison using dynamic CT analysis in healthy volunteers.
Flexible fixation techniques combined with anatomic (open) syndesmosis reduction have demonstrated improved functional outcomes and rates of malreduction. Suture-button devices allow physiologic motion of the syndesmosis without need for implant removal, which may lower the risk of recurrent syndesmotic diastasis. There is limited longer-term assessment of the maintenance of reduction between static and flexible syndesmotic fixation using bilateral ankle CT evaluation. This is an a priori planned subgroup analysis of a multi-centre, randomized clinical trial comparing static syndesmosis fixation (two 3.5 mm screws) with flexible fixation (single knotless Tightrope) for patients with AO- OTA 44-C injuries. Patients who completed bilateral ankle CT scans at 3- and 12-month follow-up were included. The primary outcome measure was syndesmotic malreduction based on bilateral ankle CT scans, using the uninjured, contralateral ankle as a control. Anterior (ASD), middle (MSD), and posterior (PSD) syndesmosis distance were calculated to measure syndesmosis reduction. Secondary outcomes included re-operation, adverse events and functional outcomes including the EQ5D, Olerud-Molander Ankle Score (OM), Foot and Ankle Disability Index (FADI), and Work Productivity Activity Impairment Questionnaire (WPAI). Paired samples t-tests were used to compare injured to control ankles (R, v 3.5.1). 42 patients (24 Group S, 18 Group T) were included. ASD for Group T was 5.22mm (95%CI 4.69–5.77) at 3 months compared to 4.26mm (95%CI 3.82–4.71; p=0.007) in controls and 5.38mm (95%CI 4.72–6.04) at 12 months compared to 4.44mm (95%CI 3.73–5.16; p=0.048) in controls. ASD for Group S was 4.63mm (95%CI 4.17– 5.10) at 3 months compared to 4.67mm (95%CI 4.24–5.10; p=0.61) in controls, but significantly increased to 5.73mm (95%CI 4.81–6.66) at 12 months compared to 4.65mm (95%CI 4.15–5.15; p=0.04) in controls. MSD results were similar; Group T had a larger MSD than control ankles at 3 months (p=0.03) and 12 months (p=0.01), while the MSD in Group S was not different at 3 months (p=0.80) but increased at 12 months (p=<0.01). 88% (21/24) of Group S had broken or removed screws by 12 months. Unplanned re-operation was 15% in Group S and 4% in Group T (p=0.02), with an overall re-operation rate of 30% in Group S. There was no significant difference between treatment groups for EQ-5D, OM, FADI or WPAI at 3- or 12-month follow-up. Tightrope fixation resulted in greater diastasis of the ASD and MSD compared to contralateral, uninjured ankles at 3- and 12-months post-fixation. Group S initially had syndesmotic reduction similar to control ankles, but between 3- and 12-months post-fixation, there was significantly increased syndesmosis diastasis compared to controls. The majority of Group S (88%) had either broken screws or scheduled screw removal, which may explain the increased tibio-fibular diastasis seen at 12-months.
Approximately 20% of patients with ankle fracture sustain syndesmosis injury. This is most common in trans-syndesmotic (type B) and supra-syndesmotic (type C) fibula fractures. Intra-operative assessment of syndesmosis integrity is important because failure to treat these injuries can result in ankle instability and pain. Our aim was to audit the documentation of intra-operative testing of syndesmosis during ankle fracture open reduction and internal fixation (ORIF). All patients who had ankle fracture ORIF between 1/1/2010 and 21/11/2011 were included. Pre-operative radiographs were reviewed and fractures were classified according to AO classification. Operation notes were reviewed for documentation of assessment of syndesmosis integrity. 153 patients, of mean age 50 years (15–93) were included. 60% (n=92) were female. In 78% of cases (n=119), an assessment of syndesmosis integrity was documented in the operation note. Of the patients with no documented syndesmosis assessment (n=35), the majority had type B fractures (n=34). One patient had a type C fracture. We have shown that 22% of patients undergoing ankle ORIF for fracture do not have documented assessment of syndesmosis integrity. We suggest that all patients who have ankle ORIF should have intra-operative assessment and documentation of syndesmosis integrity so these injuries are identified and treated accordingly.
Reoperations may be a better way of tracking adverse outcomes than complications. Repeat surgery causes cost to the system, and often indicate failure of the primary procedure resulting in the patient not achieving the expected improvement in pain and function. Understanding the cause of repeat surgery at the primary site may result in design improvements to implants or improvements to fusion techniques resulting in better outcomes in the future. The COFAS group have designed a reoperation classification system. The purpose of this study was to outline the inter and intra observer reliability of this classification scheme. To verify the inter- and intra-observer reliability of this new coding system, six fellow ship trained practicing foot and ankle Orthopaedic surgeons were asked to classify 62 repeat surgeries from a single surgeons practice. The six surgeons read the operation reports in random order, and reread the reports 2 weeks later in a different order. Reliability was determined using intraclass correlation coefficients (ICC) and proportions of agreement. The agreement between pairs of readings (915 for inter observer for the first and second read – 61 readings with 15 comparisons, observer 1 with observer 2, observer 1 with observer 3, etc) was determined by seeing how often each observer agreed. This was repeated for the 366 ratings for intra observer readings (61 times 6). The inter-observer reliability on the first read had a mean intra-class correlation coefficient (ICC) of 0.89. The range for the 15 comparisons was 0.81 to 1.0. Amongst all 1830 paired codings between two observers, 1605 (88%) were in agreement. Across the 61 cases, 45 (74%) were given the same code by all six observers. However, the difference when present was larger with more observers not agreeing. The inter-observer reliability test on the second read had a mean ICC of 0.94, with a range of 0.90. There were 43 (72%) observations that were the same across all six observers. Of all pairs (915 in total) there was agreement in 804 pairs for the first reading (88%) and disagreement in 111 (12%). For the second reading there was agreement in 801 pairs (86%) and disagreement in 114 (14%). The intra-observer reliability averaged an ICC value of 0.92, with a range of 0.86 to 0.98. The observers agreed with their own previous observations 324 times out of 366 paired readings (89% agreement of pairs). The COFAS classification of reoperations for end stage ankle arthritis was reliable. This scheme potentially could be applied to other areas of Orthopaedic surgery and should replace the Claiden Dindo modifications that do not accurately reflect Orthopaedic outcomes. As complications are hard to define and lack consistent terminology reoperations and resource utilisation (extra clinic visits, extra days in hospital and extra hours of surgery) may be more reliable measures of the negative effects of surgery.
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.
Blount's disease is by far common cause of significant genu varum in paediatric age group. The deformity can range from simple varus deformity to significant varus, shortening of tibia and internal torsion of tibia, depending up on type and stage of Blount's disease. Several studies have shown excellent correction with the use of circular frame. The trend has moved from Ilizarov circular frame to Taylor Spatial Frame. The most accepted method of achieving correction of all components is by performing proximal tibial osteotomy and gradual correction of mechanical axis. Traditionally two additional procedures – fibular osteotomy and fixation of distal tibio-fibular syndesmosis are also added. However, the role of these additional procedures, which are not without their complications, is not well evaluated. A recent study had shown that correction of tibia vara without lengthening can be achieved without fibular osteotomy. However, use of distal tibio-fibular syndesmosis fixation (either with a wire or a screw) remains controversial. We present our experience in treating Blount's deformity with circular frame without stabilization of distal tibio-fibular syndesmosis. 10 patients were treated at our tertiary referral centre between 2000 to 2010. There were 7 boys and 3 girls. Age at surgery ranged from 8 yrs – 15 yrs. The mean patient age was 11.5 yrs. Two patients were treated with Ilizarov frame and 8 with Taylor Spatial Frame. Indications for surgery were unacceptable deformity (varus and internal rotation), with or without shortening. Varus deformity ranged from 10 degrees to 40 degrees. All tibiae were lengthened and the range of lengthening was from 1cm to 3.5cm. Fibular osteotomy was carried out in all patients. Tibio-fibular syndesmosis was never stabilized distally. All the patients were encouraged to mobilise full weight bearing as soon as tolerated and all of them had gradual correction of deformity usually starting a week following the surgery. We achieved target correction of varus, internal rotation and leg length discrepancy in all patients. The commonest hurdle was superficial pin tract infection which resolved with short courses of oral antibiotics. Follow up ranged from 6 months to 10 yrs. Clinical and radiological evaluation of ankle did not show any abnormality in all these cases. Satisfactory correction of Blount's disease (tibia vara and leg length discrepancy) can be achieved with circular frame without the stabilization of distal tibio-fibular syndesmosis.
It is recommended that the ankle be held in dorsiflexion at the time of placement of syndesmosis screw. We assessed the validity of this recommendation. A two-part roentgenographic and computerised analysis of distal tibiofibular syndesmosis. The first part involved recruitment of 30 healthy adult volunteers. The second part involved 15 ankle fractures with syndesmotic injury requiring syndesmosis screw placement. In the first part individuals maximally dorsiflexed and plantarflexed their ankles in a specialised jig for standardisation. Mortice views were taken and intermalleolar distance measured. In the second part mortice views were taken in plantarflexion and dorsiflexion before and after the placement of syndesmosis screw in theatre. The intermalleolar distance was then measured.Introduction
Materials and methods
Treatment of syndesmotic injuries is a subject of ongoing controversy. Locking plates have been shown to provide both angular and axial stability and therefore could potentially control both shear forces and resist widening of the syndesmosis. The aim of this study is to determine whether a two-hole locking plate has biomechanical advantages over conventional screw stabilisation of the syndesmosis in this pattern of injury. Six pairs of fresh-frozen human cadaver lower legs were prepared to simulate an unstable Maisonneuve fracture. The limbs were then mounted on a servo-hydraulic testing rig and axially loaded to a peak load of 800N for 12000 cycles. Each limb was compared with its pair; one receiving stabilisation of the syndesmosis with two 4.5mm quadricortical cortical screws, the other a two-hole locking plate with 3.2mm locking screws (Smith and Nephew). Each limb was then externally rotated until failure occurred. Failure was defined as fracture of bone or metalwork, syndesmotic widening or axial migration >2mm. Both constructs effectively stabilised the syndesmosis during the cyclical loading within 1mm of movement. However the locking plate group demonstrated superior resistance to torque compared to quadricortical screw fixation (40.6Nm vs 21.2Nm respectively, p value <0.03). A 2 hole locking plate (3.2mm screws) provides significantly greater stability of the syndesmosis to torque when compared with 4.5mm quadricortical fixation.Conclusion
There have been few reports with efficient treatments for neglected distal tibiofibular syndesmosis disruption. Here we will report four cases of successful anatomical reconstruction with autologous gracilis tendon, using the interference fit anchoring (IFA) system. All four cases were males between 20 and 58 years of age at the time of surgery (mean age 36 years). The post-injury period to surgery was between 7 and 59 months (mean 20.1 months), with the consultation period being from 5 to 19 months (mean 9.5 months). Radiographs at the time of injuries were all malleolar fractures of pronation-external rotation (PE) stage 3 in the Lauge-Hansen classification. Stress tests for distal tibiofibular syndesmosis were positive in all cases (dilation more than 2 mm). Arthroscopic drilling was conducted in two cases with a cartilaginous injury of trochlea of talus. Distal tibiofibular syndesmosis was anatomically repositioned and was fixed with screws after bony and soft tissues within the tibiofibular syndesmosis were removed and fibular adhesion was dissected. Ipsilateral autologous gracilis tendon was passed through foramen in the insertion of the anterior inferior tibiofibular tendon on tibia and fibula, and was fixated using the IFA system. The preoperative Japanese society for surgery of the foot (JSSF) score was from 26 to 74 points (mean 43.5) and postoperative JSSF score was from 67 to 100 (mean 89.5). In a case where there was a poor outcome, five years of post injury had passed before the surgery. Although the JSSF score improved to 67 points postoperatively (from the preoperative score of 26) in this case, arthroscopic arthrodesis was conducted 5 months postoperatively due to persistent pain. Anatomical reconstruction with autologous gracilis tendon using the IFA system showed a favorable functional prognosis overall. However, there was a case with progressive degenerated changes of injured distal tibiofibular syndesmosis due to a prolonged post-injury period resulted in a poor outcome.
Introduction. In this cohort study, the TightRope® fixation technique has been compared with the traditional screw fixation for ankle syndesmosis injuries, with respect to the accuracy of the syndesmotic reduction and their clinical correlation. Patients and Methods. This cohort study included consecutive patients treated for ankle syndesmotic diastases between July 2007 and June 2009. Single slice axial CT scans of both the ankles together were performed at the level of syndesmosis, 1 cm above the tibial plafond. More than 2 mm widening of syndesmosis as compared to normal contra-lateral ankle was considered as significant malreduction. Clinical outcomes were measured using AOFAS and FADI Scores. Results. Forty-six out of 55 eligible patients attended for the study. Twenty three patients were in the tightRope group and 23 in the syndesmosis screw group. Mean follow-up was 2.5 (1.5–3.5) years. Average age was 41.6 years in tightrope group and 39.8 years in syndesmosis screw group. The mean width of normal syndesmosis was 4.01 + 0.89 mm. In tightRope group the mean width of syndesmosis was 4.37 + 1.12 mm (t-test, p = 0.30) as compared to 5.16 + 1.92 mm in screw group (t-test, p = 0.01). Five (21.7%) out of 23 ankles in screw group had syndesmotic mal reduction, while none of the tightRope group showed mal-reduction on CT scans (fisher's exact test, p = 0.04). There was no significant difference in mean post operative AOFAS score (89.56 and 86.52) and FADI score (82.42 and 81.22) between two groups. Conclusion. The results of this study indicate that tightRope provides more accurate method of syndesmosis stabilization as compared with screw fixation.
