The effect of fibular malreduction on contact pressures in an ankle fracture malunion model

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.

Influence of unstable ankle fracture (type Weber C), osteosynthesis and syndesmotic transfixation on position of fibula in tibiofibular notch: a cadaveric study

PURPOSE

The aim of the cadaveric study was to determine the effects of an unstable ankle fracture on the position of the fibula in the incisural notch and subsequently to evaluate the alterations resulting from the individual steps of a guideline-based osteosynthesis.

METHODS

In a specimen model with 20 uninjured fresh-frozen lower legs with induced unstable fracture of the fibula (type Weber C), a guideline-based osteosynthesis was performed. The distances between the anterior and posterior edges of the tibia and fibula and in the center of the incisural notch, as well as the rotation angle of the fibula, were measured in the acquired 3D image data sets and were compared with the intact condition of the ankle mortise.

RESULTS

The dissection of the syndesmosis and osteotomy of the fibula results in an external rotation the fibula by 3.6° (p = 0.000), while the distance between the anterior edge of the tibia and the fibula widens by 1.86 mm (p = 0.000). After osteosynthesis of the fibula and transfixation of the syndesmotic region using a positioning screw, the posterior distance is no longer substantially increased by 0.22 mm (p = 0.103) but also reduced by 0.1 mm (p = 0.104) in the tibiofibular notch. The external rotation of the fibula remains slightly increased by just 0.45° (p = 0.009).

CONCLUSION

The results indicate that there is a tendency for over-compression when adjusting the tibiofibular distance and that the fibula in the tibiofibular notch tends to remain slightly rotated externally.

Current Concepts in Treatment of Acute Deltoid Instability

Although far less common than lateral ankle injuries, medial ankle sprains have been reported to result in significantly greater time lost and long-term disability when not diagnosed and treated accurately. Adequate diagnosis is paramount and the most important aspect is to determine whether the lesion is stable or unstable. Evidence confronting surgical versus conservative treatment in acute deltoid ligament lesions is largely anchored in the setting of ankle fractures. Ultimately treatment decisions rely on the clinical and imaging appraisal of each individual patient. This article discusses the isolated acute deltoid ligament impairment.

Effects and Anti-rotation Stabilization of the Non-bridging External Fixation for Pronation-Abduction Stage III Ankle Fracture: A Cadaveric Study

Objective

This study is aimed at providing a nonbridging external fixation technique with pinning fixation for the pronation-abduction stage III ankle fracture. The secondary purpose was to evaluate its effect on anatomic reduction and fracture fragment stability against cadaveric models' rotation.

Method

A paired design study was conducted using 14 pairs of the cadaveric model which had been modeled for pronation-abduction stage III ankle fracture. One fracture model from each pair was randomly allocated to receive an open reduction and internal fixation, while the other was reduced and stabilized with the external fixation technique. After the surgery, the antirotational stability tests were performed with external rotation torques of 10 nm, 15 nm, and 20 nm applied, respectively. The postoperation reduction rate and ankle parameters were recorded in anteroposterior and lateral radiographs before and after the antirotational stability experiment.

Result

The outcomes were assessed according to Burwell-Charnley's radiographic criteria of reduction. It showed no statistically significant differences in reduction between the two groups (P < 0.05). The displacement of lateral fragment following a reduction in the external fixation group was significantly larger than that of the internal fixation group (3.14 ± 0.56 vs. 1.49 ± 0.39, P < 0.05). After applying rotational torques of 10 nm, 15 nm, and 20 nm, the results of other parameters showed no significant differences between the two groups.

Conclusion

This nonbridging external fixation method with pin fixation of fracture fragments might have the same effect as that of internal fixation on the reduction rate of pronation-abduction stage III ankle fracture.

Intraoperative 3D imaging in intraarticular tibial plateau fractures - Does it help to improve the patients' outcomes?

BACKGROUND

In tibial plateau fractures (TPF) the restoration of an anatomical joint surface as well as an exact subchondral screw position for postoperative stability is crucial for the outcome. The aim of this study was to determine whether the additional use of an intraoperative 3D imaging intensifier (3D) might help to improve the outcome of complex TPF.

METHODS

We performed a retrospective case-control study of a level 1 trauma center. Patients with AO/OTA 41 B3 and C-TPF operated on using a 3D imaging intensifier between November 2015 and December 2018 (3D group) were included. The outcomes of this patients were compared to patients operated without 3D imaging between January 2005 to December 2014 (2D group). The comparison of the groups was performed by matched pair analysis. The functional outcome of both groups was measured by KOOS and Lysholm Score after a follow-up period of at least 12 months. Operation time, infections and postoperative revisions were registered.

RESULTS

In total, 18 patients were included in the 3D group (mean age: 51.0± 16.4 years; 12 females) and an equal number of matching partners from the 2D group (mean age: 50.3± 15.2 years; 11 females) were found (p=0.82; p=0.79). We found 9x B3, 2x C1, 1x C2, 6x C3 fractures according to AO/OTA for each group (p=1.00) with comparable ASA score (p=0.27). The mean operation time was 127.9± 45.9 min and 116.1± 45.7 min for the 3D and 2D group (p=0.28). The mean follow-up time was 20.9± 10.7 months for the 3D and 55.5± 34.7 months for the 2D group (p< 0.001). For the 3D group a mean Lysholm overall score of 67.4± 26.8 and KOOS overall score of 72.6± 23.5 could be assessed. In contrast, a mean Lysholm overall score of 62.0± 21.4 and KOOS overall score of 65.8± 21.6 could be measured in the 2D group (p=0.39; p=0.31). Thereby, functional outcome of the 3D group showed a significant higher KOOS Sport/Rec sub score of 54.7± 35.0 in comparison to the 2D group with 26.7± 31.6 (p= 0.01). Postoperative revisions had to be performed in 27.8% of cases in both groups (p=1.00). Due to the 3D imaging an intraoperative revision was performed in 33.3% (6/18).

CONCLUSION

In our study we could show that re-reduction of the fracture or implant re-positioning were performed in relevant numbers based on the 3D imaging. This was associated with a midterm clinical benefit in regard to better KOOS Sport/Rec scores.

TRIAL REGISTRATION

AZ 488 /20-ek.

Stability-Based Classification of Ankle Fractures-The Long-Term Outcome After 11-13 Years of Follow-up

OBJECTIVES

To assess the long-term functional and radiological outcome, as well as complications and reoperations of ankle fracture patients treated based on stability classification.

DESIGN

Retrospective.

SETTING

Main Trauma Center, University Hospital.

PATIENTS AND INTERVENTIONS

One hundred sixty patients were treated based on stability classification. After a mean follow-up of 12 years, 102 patients were assessed; 67 visited the outpatient clinic, and standard standing ankle radiographs were taken; osteoarthritis (OA) was graded according to Kellgren-Lawrence classification. The remaining patients (n = 35) were followed up via mail or telephone. The complications and reoperations of all 160 patients were collected from electronic patient records.

MAIN OUTCOME MEASURES

Olerud-Molander ankle score, foot and ankle outcome score, visual analog scale, RAND-36 item health survey, range-of-motion measurements, and Kellgren-Lawrence OA classification.

RESULTS

Very good to excellent ankle functional outcome was reported by 96% of the stable fracture group [mean Olerud-Molander ankle score (OMAS), 92; range, 20-100] and 82% of the unstable group (mean OMAS, 86; range, 30-100). For patients with an unstable fracture, OMAS and VAS pain scores significantly improved from 2 to 12 years, even though higher grades of radiologic OA were found. No patients with fractures deemed stable needed operative intervention even in the long-term follow-up. Instead, 30% of the operatively treated patients underwent reoperation during the long follow-up.

CONCLUSIONS

The treatment of ankle fractures based on stability-based classification led to predictable, functionally good outcomes even during long-term follow-up. Ankle fractures can reliably be deemed stable based on this classification and treated without failures in the long term.

LEVEL OF EVIDENCE

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

Comparison of Different Magnitudes of Applied Syndesmotic Clamp Force: A Cadaveric Study

Overcompression of the ankle syndesmosis was once thought to be improbable. Recent studies using computerized tomography (CT) however, have demonstarted otherwise; raising pertinent questions regarding the factors associated with and consequences of syndesmotic overcompression. The purpose of the present study was to directly compare different magnitudes of applied clamp force on the coronal reduction of ankle syndesmosis. Eight through-the-knee cadaveric specimens were obtained. Fiducial cannulated screws were placed in the tibia and fibula to standardize placement of the reduction clamp's tines. CT scans were obtained as baseline controls, followed by destabilization of the syndesmosis. Reductions were then performed using a clamp equipped with an inline load cell, and objective forces (60, 80, 100, 120, 140, and 160 N) applied sequentially to each of the specimens. The syndesmosis was fixed with a single quadricortical screw, and CT were scans repeated. Applied clamp forces of 60 and 80 N resulted in lateral fibular displacement and undercompression (42.9% and 57.1%, respectively), whereas forces of 140 and 160 N resulted in medial fibular displacement (p = .011 and p = .001) and overcompression (100%). The smallest mediolateral displacements were observed with 100 and 120 N, respectively. Malreduction assessment with CT was superior to traditional radiographs [r(54) = 0.22; 95% confidence interval -0.04 to 0.45; p = .101]. In our cadaveric model, an applied clamp force of 100 N most effectively mitigated iatrogenic coronal syndesmotic malreduction from under- or overcompression. Although additional research is warranted, based on the data, inherent variabilities in the applied clamp force by surgeons appear to contribute to the unacceptably high coronal syndesmotic malreduction rate.

[Operative treatment of bimalleolar fractures]

OBJECTIVE

Anatomical restoration of the function and anatomy of the talocrural joint, anatomical reduction of fractures of the lateral and medial malleoli and to address ligamentous instability when achieving exercise stability.

INDICATIONS

Dislocated and intra-articular fractures of the lateral and medial malleoli.

CONTRAINDICATIONS

Infections, peripheral arterial occlusive disease, critical soft tissue conditions.

SURGICAL TECHNIQUE

Placement in a supine position, lateral and medial access, reduction of the fractures by manipulation of the fragments with Kirschner wires or use of reduction clamps, control of the joint reduction, definitive fixation with traction screws and plate osteosynthesis of the distal fibula, screw, tension-band or plate osteosynthesis of the medial malleolus, in cases of syndesmosis instability exact restoration of the talocrural joint by implantation of adjusting screws, alternatively dynamic fixation with a suture-button system.

POSTOPERATIVE MANAGEMENT

Movement exercises of the talocrural joint after postoperative day 1, mobilization with partial weight-bearing of the affected leg with 20kg postoperatively for 6-8 weeks, with implantation of adjusting screws removal after 8 weeks and staged increase of weight-bearing, if necessary postoperative insertion of an orthesis.

RESULTS

The anatomical reconstruction is decisive. Surgically treated bimalleolar fractures show good to excellent long-term results, the increasing number of affected malleoli correlates with a poorer outcome.

A standardized approach for exact CT-based three-dimensional position analysis in the distal tibiofibular joint

Background

Assessment of tibiofibular reduction presents an intra- and postoperative challenge. Numerous two-dimensional measurement methods have been described, most of them highly dependent on leg orientation and rater. Aim of the present work was to develop a standardized and orientation-independent 3D based method for the assessment of syndesmotic joint position.

Methods

In a retrospective single center study, 3D models of bilateral ankle joints, either after unilateral syndesmosis stabilization (operative group) or with no injury (native group) were superimposed (best fit matching) and aligned uniformly. Based on center of gravity calculations three orientation- and rater-independent parameters were determined: tibiofibular clears space (CS), vertical offset between both fibulae, and translation angle of the fibulae about tibia axis.

Results

Bilateral CT datasets of 57 native and 47 postoperative patients were analyzed. In the native group mean CS was 2.7 (SD, 0.8; range, 0.7–4.9) mm, mean CS side difference was 0.62 (SD, 0.45) mm and mean translation angle was 1.6 (SD, 1.4) degrees regarding absolute values. The operative group was found to show a significantly higher CS side difference of 0.88 (SD, 0.75) mm compared to native group (P = .046). Compared to the healthy contralateral side, operated fibulae showed mean proximal displacement of 0.56 (SD, 1.67) mm (P = .025), dorsal displacement of 1.5 (SD 4.1) degrees (P = .017).

Conclusion

By using 3D best fit matching, orientation- and rater-dependent errors can be minimized. Large interindividual and small intraindividual differences of uninjured couples support previous recommendations for bilateral imaging.

Trial registration: AZ 131/18-ek; AZ 361/19-ek

Level of evidence

Level III.

Indications and Surgical Treatment of Acute and Chronic Tibiofibular Syndesmotic Injuries with and Without Associated Fractures

Syndesmosis injury may occur in a wide variety of clinical scenarios. Accurate diagnosis and anatomic reconstruction are necessary for optimizing clinical outcomes. The management considerations of syndesmotic injuries with associated proximal fibula fractures are reviewed. Methods to improve the accuracy of syndesmotic reduction are outlined. The management of fractures of the posterior malleolus, Chaput tubercle, and Wagstaffe tubercle is discussed with an emphasis on their contributions to syndesmotic stability. The evolving role of flexible fixation for syndesmosis injuries is discussed. Causes and strategies for dealing with loss of reduction and malreduced syndesmotic injuries are presented.

Can a fibular malunion be corrected by a Z-shaped fibular osteotomy?

BACKGROUND

The aim of this study was to assess the short-term clinical and radiographic outcomes in patients who underwent realigning Z‑shaped fibular osteotomy.

METHODS

Between January 2007 and December 2014, 28 patients with a painful fibular malunion underwent a Z-shaped realignment fibular osteotomy. The mean age was 42.2 ± 14.1 years (range 19.1-67.8 years) and the mean follow-up was 7.0 ± 1.7 years (range 4.0-9.7 years), with no loss to follow-up. Weight-bearing radiographs were used to determine the distal fibula alignment based on Weber's criteria. Degenerative changes of the tibiotalar joint were assessed using the Kellgren-Lawrence scale. Clinical assessment included pain evaluation, measurement of ankle range of motion (ROM), sports activities, and quality of life outcomes.

RESULTS

There were no intraoperative or perioperative complications. No delayed unions or nonunions were observed. One patient had radiographic progression of degenerative changes in the tibiotalar joint. Postoperative complications included removal of hardware (n = 15) and arthroscopic tibiotalar joint debridement (n = 2). At the last follow-up the mean visual analog scale (VAS) decreased from 6.5 ± 1.1 to 2.1 ± 1.1 (p < 0.001),the ROM improved from 39º ± 6º to 45º ± 4.5º (p < 0.001), the short form health survey questionnaire (SF-36) physical and mental outcome scores improved from 49 ± 8 to 84 ± 7 (p < 0.001) and from 61 ± 4 to 83 ± 5 (p < 0.001), respectively.

CONCLUSION

The Z‑shaped realignment osteotomy of the distal fibula can provide pain relief and functional improvement in the treatment of fibular malunion. Further studies are needed to address long-term outcomes in this patient cohort.

Identifying Intra-Articular Pathology With Arthroscopy Prior to Open Ankle Fracture Fixation

Purpose

To assess the prevalence of intra-articular findings with ankle arthroscopy in patients undergoing operative fixation for ankle fractures.

Methods

This is a retrospective review of ankle fractures that were treated with arthroscopy and open reduction and internal fixation by a single surgeon. Between August 2016 and July 2018, operative reports, office notes, and images were reviewed to identify intra-articular pathology and fracture type. An analysis was performed with regard to fracture type, presence and location of osteochondral lesions, loose-bodies, syndesmotic injury, and deltoid injury.

Results

Fifty-seven ankle fractures were identified that met inclusion criteria. In total, 84.2% of the fractures had intra-articular pathology, most commonly a syndesmotic injury followed by presence of intra-articular loose bodies and osteochondral defects.

Conclusions

In our study, use of arthroscopy before open ankle fracture fixation identified intra-articular pathology in 84.2% of subjects. The most common pathology was syndesmotic injury. The addition of an arthroscopic assessment in patients with operatively treated ankle fractures may help improve treatment provided to patients during ankle fracture surgery.

Level of Evidence

Level 4 Therapeutic Case Series.

Chronic Syndesmotic Injuries: Arthrodesis versus Reconstruction

"Chronic syndesmotic injury covers a broad range of symptoms and pathologies. Anterolateral ankle impingement without instability is treated by arthroscopic debridement. Subacute, unstable, syndesmotic injuries are treated by arthroscopic or open debridement followed by secondary stabilization using suture button device or permanent screw placement. Chronic syndesmotic instability is treated by a near-anatomic ligamentoplasty supplemented by screw fixation. In case of poor bone stock, failed ligament reconstruction, or comorbidities, tibiofibular fusion with bone grafting is preferred. Malleolar malunions and particularly anterior or posterior syndesmotic avulsions must be corrected in order to achieve a stable and congruent ankle mortise."

Reliability of Postoperative Radiographies in Ankle Fractures

Background

The accuracy of reduction of ankle fractures using postoperative plain radiographies (x-ray) remains widely controversial. Some authors have demonstrated that postoperative computed tomography (CT) scan can be useful for these patients. In current study, the efficacy of x-rays after fixation of ankle fractures was investigated based on the CT scan findings.

Methods

A total of 73 patients with ankle fractures who were subjected to open reduction internal fixation (ORIF) were enrolled. After surgery, if the reduction was acceptable based on the x-rays according to standard measurements, the patient was referred for CT scanning. Forty four patients were included in the study. Undesirable CT scan findings including malreduction of fragments or articular surfaces, device malpositioning, missed fractures, and undetected intra-articular fragments were documented.

Results

Undesirable CT findings were seen in 25 patients (56.8%). CT scan showed acceptable reduction without device malpositioning in 19 patients. The most prevalent findings in CT images were malreduction and device malpositioning in 17 and 16 patients, respectively. There was no abnormal finding in CT imaging of lateral malleolar fractures. In two thirds of the injured syndesmosis, device malpositioning, and malreduction were detected in CT scan.

Conclusion

Despite acceptable postoperative x-rays, a considerable number of patients with ankle fractures had inappropriate reduction or undesirable findings in their postoperative CT scan. It seems necessary to use CT scan after ORIF of ankle fractures in order to examine the accuracy of reduction. Further validation of postoperative CT scan in ankle fracture surgery should be investigated.

Anterior Syndesmotic Augmentation Technique Using Nonabsorbable Suture-Tape for Acute and Chronic Syndesmotic Instability

Syndesmotic instability is a source of significant pain and disability. Both subtle instability and gross diastasis, whether acute or chronic, require stabilization and may benefit from reconstruction with ligamentous augmentation. The use of nonabsorbable suture-tape has emerged as a promising operative strategy, allowing surgeons to anatomically reconstruct the syndesmosis, in particular the anterior inferior tibiofibular ligament. The current work provides a detailed description of the technique and preliminary results of a patient cohort treated using nonabsorbable suture-tape for syndesmotic augmentation.Level of Evidence: Level V, expert opinion.

Biomechanical Evaluation of a New Suture Button Technique for Reduction and Stabilization of the Distal Tibiofibular Syndesmosis

Background:

Stabilization methods for distal tibiofibular syndesmotic injuries present risk of malreduction. We compared reduction accuracy and biomechanical properties of a new syndesmotic reduction and stabilization technique using 2 suture buttons placed through a sagittal tunnel in the fibula and across the tibia just proximal to the incisura with those of the conventional method.

Methods:

Syndesmotic injury was created in 18 fresh-frozen cadaveric lower leg specimens. Nine ankles were repaired with the conventional method and 9 with the new technique. Reduction for the conventional method was performed using thumb pressure under direct visualization and for the new method by tightening both suture buttons passed through the fibular and tibial tunnels. Computed tomography was used to assess reduction accuracy. Torsional resistance, fibular rotation, and fibular translation were evaluated during biomechanical testing.

Results:

The new technique showed less lateral translation of the fibula on CT measurements after reduction (0.06 ± 0.06 mm) than the conventional method (0.26 ± 0.31 mm), P = .02. The new technique produced less fibular rotation during internal rotation after 0 cycles (new –2.4 ± 1.4 degrees; conventional –5.0 ± 1.2 degrees, P = .001), 100 cycles (new –2.1 ± 1.9 degrees; conventional –4.6 ± 1.4 degrees, P = .01), and 500 cycles (new –2.2 ± 1.6 degrees; conventional –5.3 ± 2.5 degrees, P = .01) and during external rotation after 100 cycles (new 3.9 ± 3.3 degrees; conventional 5.9 ± 3.5 degrees, P = .02) and 500 cycles (new 3.3 ± 3.2 degrees; conventional 6.3 ± 2.6 degrees, P = .03). Fixation failed in 3 specimens.

Conclusion:

The new syndesmotic reduction and fixation technique resulted in more accurate reduction of the fibula in the tibial incisura in the coronal plane and better rotational stability compared with the conventional method.

Clinical Relevance:

This new technique of syndesmosis reduction and stabilization may be a reliable alternative to current methods.

Ankle joint re-balancing in the management of ankle fracture malunion using fibular lengthening: prospective clinical-radiological results at mid-term follow-up

PURPOSE

An unsatisfactory reduction and internal fixation of an ankle fracture can result in an alteration of the anatomical axes and distribution of the load on the ankle, with consequent development of chronic pain and articular degeneration. The aim of this study is to evaluate the results of the articular re-balancing with realignment and lengthening of the fibula in case of malunited distal fibular fractures.

METHODS

A review of prospectively collected data was performed for all patients with a diagnosis of malunion of the fibula and underwent ankle joint re-balancing with fibular lengthening. Twenty-three patients, with a mean age of 39.4 ± 13.1 years, have been evaluated using radiographic parameters, American Orthopaedic Foot and Ankle Surgeons ankle-hindfoot, Ankle Activity scale, and SF-36 score at six, 12, 24, and 36 months post-operatively.

RESULTS

All cases treated showed at follow-up the osteotomy healed in good correction of the deformities. Clinical scores showed a clear improvement: final 36-month mean AOFAS was 74.0 ± 8.9 point, final 36-month mean HALASI score was 4.9 ± 0.9 points, 36-month follow-up SF-36 score showed an average score of 73.2 ± 10.7 points. Pre- and post-operative radiographic parameters have been registered and described.

CONCLUSIONS

The ankle joint is a complex structure, and even minor changes of the structure of this joint can significantly compromise its functionality. Ankle joint re-balancing is an effective surgical procedure in case of fibular malunion. This procedure, in patients carefully selected, could procrastinate more disabling surgical procedure, as arthrodesis or prosthesis.

[Clinical analysis of full-repair strategy under small incision for closed Lauge-Hansen pronation-external rotation type ankle fracture]

OBJECTIVE

To investigate the safety, feasibility, and efficacy of full repair strategy under small incision in the treatment of closed Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture.

METHODS

The clinical data of 57 patients with closed Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture treated by full repair strategy (fracture, ligament, and cartilage repair) under small incision between January 2012 and January 2017 were retrospectively analyzed. There were 31 males and 26 females, with an average age of 41.1 years (range, 21-65 years). The causes of injury included traffic accident injury in 33 cases and falling injury in 24 cases. All of them were closed fractures, including 20 cases of medial malleolus fracture, 37 cases of complete medial malleolus but deep and shallow rupture of deltoid ligament. The average time from injury to admission was 9.6 hours (range, 3-34 hours). The quality of reduction of distal tibial articular surface (based on Ketz-Sanders standard), the reduction of tibiofibular syndesmosis (the anterior and posterior distances of distal tibiofibular syndesmosis and the lateral ankle twist angle measured by CT scan at 10 mm above the ankle joint line), and the fracture healing were evaluated. The medial clear space (MCS), tibiofibular clear space (TFCS), and distal fibular tip to lateral process of talus (DFTL) were measured on the X-ray films of ankle points. Before and after operation, the pain and functional improvement of ankle joint were evaluated by visual analogue scale (VAS) score and American Orthopedic Foot and Ankle Association (AOFAS) score, and the activities of ankle dorsiflexion and plantar flexion were measured.

RESULTS

Three cases with osteochondral lesions of the talus were found during operation and all were treated with microfracture techniques. Tournament paralysis occurred in 2 cases after anesthesia. The surgical incisions healed by first intention in all patients. All the 57 patients were followed up 24-84 months, with an average of 38.6 months. All patients achieved bone healing without bone nonunion and malunion at 12 months after operation. The reduction quality of distal tibial articular surface was excellent in 56 cases and good in 1 case at 3 months after operation, the excellent and good rate was 100%. There was no significant difference in the MCS, TFCS, DFTL, anterior distance of distal tibiofibular syndesmosis, posterior distance of distal tibiofibular syndesmosis, and lateral ankle twist angle between the affected and healthy sides at 12 months after operation ( P>0.05). At last follow-up, the VAS score, AOFAS score, ankle dorsiflexion and plantar flexion activities of the affected side were significantly improved when compared with preoperative ones ( P<0.05). Compared with the healthy side, there was no significant difference in ankle dorsiflexion and plantar flexion activities ( P>0.05).

CONCLUSION

Full-repair strategy under small incisions for the treatment of Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture is effective and safe. It can not only reduce wound complications, but also improve the quality of joint reduction of the ankle joint and distal tibiofibular syndesmosis. Full repair of ligaments and cartilage can improve the internal fixation strength and joint stability of the ankle joint.

Reconstruction of Severe Ankle and Pilon Fracture Malunions

Malunion of ankle and pilon fractures has significant detrimental effect on function and development of post-trauma osteoarthritis. Unfortunately, the incidence of malunion has been reported to be increasing. It is important to assess the ankle for congruency, because this determines the level where correction will occur. A plethora of techniques are available, with low-level evidence supporting each, and therefore it is important that the treating surgeon is fully prepared and comfortable in the techniques they are to use. Supplementary procedures are common and should be expected. This article provides a review of current methods of treatment and their outcomes.

Validation of a new method for evaluation of syndesmotic injuries of the ankle

PURPOSE

To define a new parameter in CT that could make imaging of the contralateral ankle dispensable evaluating the position of the fibula after syndesmotic injury.

METHODS

Thirty bilateral CTs of 30 patients were included. Five parameters were defined in axial CT for the injured (_inju) and uninjured (_unin) ankle. Reproducibility was examined for inter-observer and intra-observer reliability. Comparisons for all parameters were performed between the CT scans of both ankles.

RESULTS

All measurements had a high agreement for the inter-observer and intra-observer correlation coefficients. A large interindividual variance could be found between all parameters. If the difference of the anterior tibiofibular distance antTFD_unin and antTFD_inju was less than 2 mm, there was a strong significant pairwise correlation between all parameters between both sides.

CONCLUSION

Bilateral CT is still to be recommended, as it is the only way to exactly assess anterior posterior reduction of the fibula.

Kinematic Analysis of Combined Suture-Button and Suture Anchor Augment Constructs for Ankle Syndesmosis Injuries

BACKGROUND

Syndesmosis injuries are common, with up to 25% of all ankle injuries being reported to involve an associated syndesmosis injury. These injuries are typically treated with cortical screw fixation or suture-button implants when indicated, but the addition of a suture anchor augment implant has yet to be evaluated. The purpose of this study was to evaluate the ability of a suture anchor augment to add sagittal plane translational and transverse plane rotational constraint to suture-button constructs with syndesmosis injuries. We hypothesized that the suture anchor augment oriented in parallel with the fibers of an injured anterior-inferior tibiofibular ligament (AITFL) in addition to a suture-button construct would achieve physiological motion and stability at the syndesmosis through increased rotational and translational constraint of the fibula.

METHODS

Eleven fresh-frozen cadaver ankles were stressed in external rotation using a custom-made ankle rig. Each ankle had simultaneous recording of ultrasound video, 6 degrees-of-freedom kinematics of the fibula and tibia, and torque as the ankle was stressed by an examiner. The ankles were tested in 6 different states: native uninjured; injured with interosseous ligament and AITFL sectioned; 1× suture button; 2× suture buttons, divergent; 1× suture anchor augment with 2× suture buttons, divergent; and 1× suture anchor augment with 1× suture buttons.

RESULTS

Only the suture anchor augment + 2× suture buttons and suture anchor augment + 1× suture-button constructs were found to be significantly different from the injured state (P = .0003, P = .002) with mean external rotation of the fibula.

CONCLUSION

Overall, the most important finding of this study was that the addition of a suture anchor augment to suture-button constructs provided a mechanism to increase external rotational constraint of the fibula.

CLINICAL RELEVANCE

This study provides a mechanistic understanding of how the combined suture-button and suture anchor augment construct provides an anatomically similar reconstruction of constraints found in the native ankle. However, none of the constructs examined in this study were able to fully restore physiologic motion.

Fibular-Lengthening Osteotomy in Patient with Progressive Valgus Deformity After an Ankle Fracture

Patient: Male, 23-year-old

Final Diagnosis: Malunion fracture of the fibula

Symptoms: Pain and limited movement in the right ankle

Medication:—

Clinical Procedure: Fibular-lengthening osteotomy

Specialty: Orthopedics and Traumatology

Early Corrections after Failed Ankle Fracture Fixation

Even minor residual fragment malpositioning after internal fixation of ankle fractures is associated with a worse prognosis. Frequent causes for non-anatomical reduction are fibular shortening due to comminuted fractures or poor bone quality, translational or rotational malpositioning of the distal fibula within the tibial incisura with unstable syndesmosis injuries, and inadequately addressed bony avulsions of the tibiofibular syndesmosis. After operative treatment of fracture dislocations with syndesmotic fixation, in case of complex fracture pathoanatomy, and with suspected non-anatomic reduction in postoperative radiographs, computed tomography imaging of both ankles should be performed. Correction of relevant malreductions should be performed as early as possible in order to speed up rehabilitation and to avoid late sequelae due to a load shift or instability in a weight-bearing joint.

Sagittal ankle position does not affect axial CT measurements of the syndesmosis in a cadaveric model

BACKGROUND

The purpose of this study was to evaluate the effect of ankle plantarflexion and the axial location of measurement on quantitative syndesmosis assessment.

METHODS

Twelve fresh-frozen cadaveric specimens were secured in three positions of ankle plantarflexion (0°, 15°, and 30°) using an ankle-spanning external fixator and underwent CT scans at each position. Syndesmotic measurements were obtained on axial images using three previously described methods (six measurements) at the level of the tibial plafond and 1 cm proximal to the plafond. Method 1 evaluated the distance between the most anterior and posterior aspects of the fibula and tibia. Method 2 measured medial-lateral diastasis of the anterior and posterior aspects of the fibula, and fibular anterior-posterior translation. Method 3 evaluated axial rotation of the fibula. All measurements were performed by two independent observers. Inter-rater reliability of each measurement was evaluated using intra-class coefficients. Repeated measures analysis of variance (RM-ANOVA) was performed to evaluate within-specimen differences in measurements obtained at varying ankle positions.

RESULTS

The anterior incisura component of method 1 demonstrated poor-to-moderate inter-rater reliability across all ankle positions and at both measurement locations. Inter-rater reliability was highest for method 2, especially when measured 1 cm proximal to the plafond. Method 3 demonstrated moderate reliability 1 cm proximal to the plafond. After correcting for multiple comparisons, RM-ANOVA and pairwise analysis revealed that none of the measurements changed significantly with varying ankle position.

CONCLUSION

The inter-rater reliability of the most common method of syndesmotic evaluation (method 1) was found to be lower than in previous studies. The most reliable syndesmotic evaluation can be made by measuring diastasis and anteroposterior translation 1 cm proximal to the plafond (method 2). Ankle position from 0° to 30° of plantarflexion did not change the measurements obtained.

LEVEL OF EVIDENCE

IV.

A reliable method for intraoperative detection of lateral malleolar malrotation using conventional fluoroscopy

OBJECTIVE

To introduce a new method for intraoperative detection of rotational malreduction of the lateral malleolus using conventional fluoroscopy.

MATERIAL AND METHODS

From January 2014 to December 2017, 56 Weber type C unstable lateral malleolar fractures with syndesmosis injury were identified. The fibular fracture patterns were simple oblique or transverse in 20, comminuted in 25, and Maisonneuve injury with fibular neck fractures in 11 cases. 47 cases were operated with ORIF, and 9 cases of Maisonneuve fractures were operated with CRIF. The mortise view of the contralateral uninjured ankle was used for intraoperative comparison. Two indexes were applied for fluoroscopic detection of distal fibula malrotation, i.e. the contour profile change in lateral malleolar shape, and the intrinsic structure appearance of lateral malleolar fossa cortex. Postoperative talofibular joint congruency was measured on axial CT scan to confirm the reduction quality.

RESULTS

Using the two radiographic parameters for intraoperative fluoroscopic evaluation, we finally achieved satisfying reduction and fixation of the lateral malleolus in all 56 cases. A more spoon-shaped fibula profile and disappearance of the lateral fossa cortex shadow indicates an internal rotation, while a more pointed blade-shaped fibula profile and disappearance of lateral fossa cortex shadow indicates an external rotation. Postoperative CT scanning identified distal fibular no rotation in 44 cases (78.6%), mild rotation less than 5° in 12 cases (21.4%), with 7 cases internal rotation (mean 3.1°) and 5 cases external rotation (mean 2.8°).

CONCLUSION

Using conventional intraoperative fluoroscopy on mortise view, new radiographic parameters can provide reliable method to detect rotational malreduction of the lateral malleolus.

Comparison of three different reduction methods of the ankle mortise in unstable syndesmotic injuries

In order to achieve a clinically satisfying result and to prevent posttraumatic osteoarthritis in the treatment of unstable syndesmotic injuries, anatomically correct reduction is crucial. The objective of the study was to investigate three different reduction methods of the ankle mortise in unstable syndesmotic injuries. In a specimen model with 38 uninjured fresh-frozen lower legs, a complete syndesmotic dissection was performed. The ankle mortise was reduced with either a collinear reduction clamp, a conventional reduction forceps or manually with crossing K-wires. The reduction clamps and the K-wires were placed in a 0°-angle to the leg axis. The clamps were positioned on the posterolateral ridge of the fibula 20 mm proximal to the ankle joint line. A cone beam computed tomography was performed after dissection and after each reduction. Tibio-fibular distances and angles were determined. Despite significant differences in terms of overcompression (0.09–0.33 mm; p = 0.000–0.063) and the slight external rotation (0.29–0.47°; p = 0.014–0.07), the results show a satisfying reduction of the ankle mortise. There were no considerable differences between the reduction methods. It can therefore be concluded that the ankle mortise can be reduced with any of the methods used, but that the positioning and the contact pressure must be considered.

Screw fixation of the syndesmosis alters joint contact characteristics in an axially loaded cadaveric model

BACKGROUND

The purpose of this study was to quantify the effects of rigid syndesmotic fixation on functional talar position and cartilage contact mechanics.

METHODS

Twelve below-knee cadaveric specimens with an intact distal syndesmosis were mechanically loaded in four flexion positions (20° plantar flexion, 10° plantar flexion, neutral, 10° dorsiflexion) with zero, one, or two 3.5-mm syndesmotic screws. Rigid clusters of reflective markers were used to track bony movement and ankle-specific pressure sensors were used to measure talar dome and medial/lateral gutter contact mechanics.

RESULTS

Screw fixation caused negligible anterior and inferior shifts of the talus within the mortise. Relative to no fixation, mean peak contact pressure decreased by 6%-32% on the talar dome and increased 2.4- to 6.6-fold in the medial and lateral gutters, respectively, depending on ankle position and number of screws.

CONCLUSIONS

Two-way ANOVA indicated syndesmotic screw fixation significantly increased contact pressure in the medial/lateral gutters and decreased talar dome contact pressure while minimally altering talar position.

Defining the three most responsive and specific CT measurements of ankle syndesmotic malreduction

PURPOSE

The purpose of this study was to compare the reliability and accuracy of existing computed tomography (CT) methods for measuring the distal tibiofibular syndesmosis in uninjured, paired cadaveric specimens and in simulated malreduction models. It was hypothesized that a repeatable set of measurements exists to accurately and quantitatively describe the typical forms of syndesmotic malreduction using contralateral ankle comparison.

METHODS

Twelve cadaveric lower-leg specimen pairs were imaged with CT to generate models for this study. Thirty-five measurements were performed on each native model. Next, four distinct fibular malreductions were produced via digital simulation and all measurements were repeated for each state: (1) 2-mm lateral translation; (2) 2-mm posterior translation; (3) 7-degree external rotation; (4) the previous three states combined. The modified standardized response mean (mSRM) was calculated for each measurement. To assess rater reliability and side-to-side agreements of the native state measurements, intraclass correlation coefficients (ICC) and Pearson correlation coefficients (PCC) were calculated, respectively.

RESULTS

The most responsive measurements for detecting isolated malreduction were the Leporjärvi clear space for lateral translation, the Nault anterior tibiofibular distance for posterior translation, and the Nault talar dome angle for external rotation of the fibula. These measurements demonstrated fair to excellent inter-rater ICCs (0.64-0.76) and variable side-to-side PCCs (0.14-0.47).

CONCLUSIONS

The most reliable method to assess the syndesmosis on CT was to compare side-to-side differences using three distinct measurements, one for each type of fibular malreduction, allowing assessment of the magnitude and directionality of syndesmosis malreduction. Reliable evaluation is essential for assessing subtle syndesmosis injuries, malreduction and surgical planning.

Reducing the Syndesmosis Under Direct Vision: Where Should I Look?

OBJECTIVES

To compare the quality of syndesmotic reduction obtained using the incisura versus the ankle articular surface as the visual cue. Secondarily, we evaluated the difference in the anterior to posterior depth of the fibula to the tibia at the joint level and the fibula to the incisura 1 cm above the joint.

METHODS

Seven surgeons reduced disrupted syndesmoses of 10 cadaveric ankles using either the anterolateral articular surface of the distal tibia to the anteromedial fibular articular surface or the location of the fibula within the incisura as a visual reference. Malreductions in translation were measured in millimeter from the anatomical position of the fibula. The anterior to posterior distances of the tibia and fibula were also measured at both levels to determine the differences in their depths.

RESULTS

The translational reduction was within 2 mm in 93% (0.7 ± 0.7 mm) of reductions using the articular surface as a reference compared with 80% (1.2 ± 1.0 mm) using the incisura as a reference (P = 0.0001). All surgeons' reductions were better using the joint articular surface as the visual reference. The difference in the fibular and the tibial depth was smaller at the level of the articular surface versus the incisura (2.1 mm vs. 5.9 mm; P = 0.0002).

CONCLUSIONS

The articular surface is a significantly more accurate visual landmark for translational reduction of the syndesmosis. This is potentially explained by the larger differences in the fibula and tibial depth at the incisura versus the articular surface.

Plausible mechanisms of and techniques to assess ankle joint degeneration following lateral ankle sprains: a narrative review

Lateral ankle sprain (LAS) is the most common lower extremity musculoskeletal injury sustained during daily life and sport. The cascade of events that starts with ligamentous trauma leads to clinical manifestations such as recurrent sprains and giving way episodes, hallmark characteristics of chronic ankle instability (CAI). The sequelae of lateral ankle sprains and CAI appear to contribute to aberrant biomechanics. Combined, joint trauma and aberrant biomechanics appear to directly and/or indirectly play a role in talar cartilage degeneration. Up to 80% of all cases of ankle osteoarthritis (OA) are post-traumatic in nature and common etiologies for ankle post-traumatic osteoarthritis (PTOA) are histories of a single and recurrent ankle sprains. Despite known links between LAS, CAI, and PTOA and evidence demonstrating the burden of LAS and its sequelae, early pathoetiological changes of ankle PTOA and how they can be assessed are poorly understood. Therefore, the purpose of this paper is to review the plausible mechanistic links among LAS and its sequelae of CAI and PTOA as well as review non-surgical techniques that can quantify talar cartilage health. Understanding the pathway from ligamentous ankle injury to ankle PTOA is vital to developing theoretically sound therapeutic interventions aimed at slowing ankle PTOA progression. Further, directly assessing talar cartilage health non-surgically provides opportunities to quantify if current and novel intervention strategies are able to slow the progression of ankle PTOA.

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.

Lower Complication Rate Following Ankle Fracture Fixation by Orthopaedic Surgeons Versus Podiatrists

INTRODUCTION

Increased overlap in the scope of practice between orthopaedic surgeons and podiatrists has led to increased podiatric treatment of foot and ankle injuries. However, a paucity of studies exists in the literature comparing orthopaedic and podiatric outcomes following ankle fracture fixation.

METHODS

Using an insurance claims database, 11,745 patients who underwent ankle fracture fixation between 2007 and 2015 were retrospectively evaluated. Patient data were analyzed based on the provider type. Complications were identified by the International Classification of Diseases, Ninth Revision, codes, and revision surgeries were identified by the Current Procedural Terminology codes. Complications analyzed included malunion/nonunion, infection, deep vein thrombosis, and rates of irrigation and débridement. Risk factors for complications were compared using the Charlson Comorbidity Index.

RESULTS

Overall, 11,115 patients were treated by orthopaedic surgeons and 630 patients were treated by podiatrists. From 2007 to 2015, the percentage of ankle fractures surgically treated by podiatrists had increased, whereas that treated by orthopaedic surgeons had decreased. Surgical treatment by podiatrists was associated with higher malunion/nonunion rates among all types of ankle fractures. No differences in complications were observed in patients with unimalleolar fractures. In patients with bimalleolar or trimalleolar fractures, treatment by a podiatrist was associated with higher malunion/nonunion rates. Patients treated by orthopaedic surgeons versus podiatrists had similar comorbidity profiles.

DISCUSSION

Surgical treatment of ankle fractures by orthopaedic surgeons was associated with lower rates of malunion/nonunion when compared with that by podiatrists. The reasons for these differences are likely multifactorial but warrants further investigation. Our findings have important implications in patients who must choose a surgeon to surgically manage their ankle fracture, as well as policymakers who determine the scope of practice.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Influence of ankle joint position on angles and distances of the ankle mortise using intraoperative cone beam CT: A cadaveric study

BACKGROUND

The precise anatomical reduction of the ankle mortise is crucial for the clinical outcome in unstable syndesmotic injuries. Intraoperative cone beam computed tomography (CT), in addition to two-dimensional fluoroscopy, provides detailed information about the reduction and implant placement. The aim of this study was to analyze the influence of the joint position on the fibula position in the incisural notch and to determine the inter- and intraindividual anatomical differences in the intact ankle joints.

METHODS

A total of 20 fresh-frozen lower legs disarticulated in the knee joint of 10 individuals were included. The measurements were performed using a cone beam CT. The distances and angles were measured in the standard imaging planes. The mean values of distances and angles were compared during the different joint positions: 10° dorsiflexion, 0° neutral position and 20° plantar flexion.

RESULTS

The influence of the joint position was on average as follows: The anterior tibiofibular distance was 3.68 mm in 10° dorsiflexion, 3.66 mm (0° neutral position) and 3.59 mm (20° plantar flexion). The posterior tibiofibular distance measured 7.82mm, 7.76mm and 7.82mm. The rotation of the fibula measured ten millimeters proximal the joint line was 1.2°, 1.3° and 1.05°. The fibular rotation determined 4mm was 9.3°, 9.4° and 9.4°. On average, the following intraindividual variations were observed: superior tibiotalar clear space of 0.27mm and 0.15mm medial; and anterior tibiofibular distance of 0.42mm, 0.38mm posterior and 0.24mm in the incisural notch. The proximal angle of the fibular rotation was 0.2° and distal 0.4°. The interindividual variations of the angles and distances exceeded the intraindividual values partly by 3 to 4 fold.

CONCLUSIONS

Within the scope of this study neither the tibiofibular distance, nor the tibiofibular angle changed significantly through the different joint positions. The intraindividual differences were little while the interindividual variations of the parameters were distinctive.

A standardised computed tomography measurement method for distal fibular rotation

PURPOSE

The aim of the study is to identify an ideal location to measure fibular rotation in the ankle joint using axial computed tomography (CT) scans. Another objective was to detect the average fibular rotation in the uninjured ankle joint in a large cohort.

METHODS

Standardised axial CT with coronal/sagittal reconstructions was performed in healthy ankle joints. Three investigators performed the measurements. In the axial view, each investigator appointed the ideal location to measure the angle of fibular rotation with the use of reference lines either 4, 6, 8 or 10 mm distal from the talar joint line. Inter- and intraobserver reliability, as well as the intraclass correlation coefficient, were determined.

RESULTS

CT scans of one hundred individuals-78 males and 22 females-were analysed. The most common locations for measuring the fibular rotation were in 31% of cases 4 mm and in 51% of cases 6 mm distal the talar joint line. The external rotation of the fibula averaged 8.42° ± 4.86° (range 0°-26°). The intraclass coefficient correlations (ICC) for interrater and intrarater reliability were 0.75.

CONCLUSIONS

The results of the study demonstrate a reproducible location to measure the fibular rotation in the ankle joint. The most convenient location to measure fibular rotation with a high reliability was 6 mm distal to the talar joint line.

Distal fibular malrotation and lateral ankle contact characteristics

BACKGROUND

Any amount of malreduction of the syndesmotic joint compared with the uninjured syndesmosis has been associated with an adverse effect on functional outcome. The amount of malrotation that may lead to clinically relevant pressure change in this joint has not been reported. Our purpose was to determine whether small degrees of external and internal malrotation would be associated with statistically significant changes in contact pressure in the tibiofibular and talofibular articulations.

METHODS

Twelve cadaveric ankles were osteotomized above the syndesmosis and instrumented with a rotatable distal fibula plate. Sensors at the distal tibiofibular and talofibular articulations recorded contact pressure and area at neutral position and at 5 and 10° of external and internal malrotation through a full range of ankle motion.

RESULTS

Compared with neutral rotation, there was a significant decrease in contact pressure at the talofibular articulation with external rotation of 5° (103±113kPa versus 52±69kPa; P=0.01) and 10° (43±62kPa; P=0.01) in plantarflexion.Contact pressure at the tibiofibular articulation in plantarflexion increased with 10° of internal malrotation compared with neutral rotation (56±30kPa versus 74±38kPa; P=0.05) in plantarflexion. Contact area decreased significantly with plantarflexion and 10° of external rotation and increased significantly in plantarflexion and after cyclic loading with 10° of internal rotation (P≤0.05).

CONCLUSION

Any degree of distal fibular external rotation significantly reduced contact pressure in the talofibular articulation with plantarflexion. A minimal increase in contact pressure was found in the tibiofibular and talofibular joints with plantarflexion and mild internal rotation of 5°, but pressure increased significantly in both articulations with 10° of internal rotation. The findings support clinical findings that subtle degrees of fibular malrotation may be associated with alteration of lateral ankle mechanics.

LEVEL OF EVIDENCE

Controlled biomechanical study.

Screw distraction technique for gaining fibular length

Shortening of fibular length is most commonly secondary to fracture, especially in cases of malreduction, malunion or nonunion. In the presence of deltoid ligament incompetence, a shortened fibula causes lateral talar shift, widening of the mortise, decreased tibiotalar contact area and increased incidence of post-traumatic arthrosis. Restoring fibular length is important for normal anatomic relationships and kinematics of the ankle joint. While several techniques have been described for restoring length, some limitations exist. We describe an alternative surgical technique that is straightforward and reproducible that allows for restoration of fibular length and rotation.

Acute and Chronic Syndesmotic Injury: The Authors' Approach to Treatment

Ankle injuries are a common traumatic injury. Rupture to the syndesmosis may occur as a result of these injuries. Strategies for the treatment of both acute and chronic syndesmotic repair are reviewed in detail. Significance of Chaput, Wagstaffe, and posterior malleolus fractures on syndesmotic stability are reviewed. Treatment considerations for total ankle arthroplasty are discussed, and correction of coronal plane deformity as a result of late syndesmotic injury at the time of ankle arthroplasty is outlined.

Radiographic Assessment of Fibular Length Variance: The Case for "Fibula Minus"

Given the high prevalence of ankle fractures and morbidity of malalignment after fixation, an appropriate anatomic relationship between the distal fibula and adjacent tibia and talus is important. The tip of the lateral malleolus of the fibula has often been described to be at the level of the lateral talar process. However, no studies to date have examined the relationship of the distal fibular tip to the lateral process of the talus. We assessed 66 weightbearing mortise radiographs for variability of the distal fibular tip in relation to the lateral process of the talus. The subjects were all skeletally mature, with a mean age of 45.3 ± 14.6 years. We used a paired t test with a null hypothesis that the true mean difference in the distance from the distal fibula to the lateral process was equal to 0. The mean distance of the distal tip of the fibula was 0.257 ± 0.127 cm proximal to the tip of the lateral process of the talus. The 95% confidence interval was 0.226 to 0.288. Of the 66 subjects, 65 had the distal tip of the fibula proximal to the lateral process of the talus, corresponding to a negative fibular variance. In the remaining subject, the distal tip of the fibula was at the same level of the tip as the lateral process of the talus. The distal tip of the fibula is most commonly not at the level of the talus lateral process, as often described in published reports. Instead, it has a variance analogous to the relationship between the lengths of the ulna compared with the radius. The distal tip of the fibula in our study was more often proximal to the tip of the lateral process of the talus and can be described as a negative fibular variance, or "fibula minus."

Headless compression screw for horizontal medial malleolus fractures

BACKGROUND

Horizontal medial malleolus fractures are caused by the application of rotational force through the ankle joint in several orientations. Multiple techniques are available for the fixation of medial malleolar fractures.

METHODS

Horizontal medial malleolus osteotomies were performed in eighteen synthetic distal tibiae and randomized into two fixation groups: 1) two parallel unicortical cancellous screws or 2) two Acutrak 2 headless compression screws. Specimens were subjected to offset axial tension loading. Frontal plane interfragmentary motion was monitored.

FINDINGS

The headless compression group (1699 (SD 947) N/mm) had significantly greater proximal-distal stiffness than the unicortical group (668 (SD 298) N/mm), (P = 0.012). Similarly, the headless compression group (604 (SD 148) N/mm) had significantly greater medial-lateral stiffness than the unicortical group (281 (SD 152) N/mm), (P < 0.001). The force at 2 mm of lateral displacement was significantly greater in the headless compression group (955 (SD 79) N) compared to the unicortical group (679 (SD 198) N), (P = 0.003). At 2 mm of distal displacement, the mean force was higher in the headless compression group (1037 (SD 122) N) compared to the unicortical group (729 (SD 229) N), but the difference was not significant (P = 0.131).

INTERPRETATION

A headless compression screw construct was significantly stiffer in both the proximal-distal and medial-lateral directions, indicating greater resistance to both axial and shear loading. Additionally, they had significantly greater load at clinical failure based on lateral displacement. The low-profile design of the headless compression screw minimizes soft tissue irritation and reduces need for implant removal.

Mini-Fragment Fixation Is Equivalent to Bicortical Screw Fixation for Horizontal Medial Malleolus Fractures

Horizontal fractures of the medial malleolus occur through application of valgus or abduction force through the ankle that creates a tension failure of the medial malleolus. The authors hypothesize that mini-fragment T-plates may offer improved fixation, but the optimal fixation construct for these fractures remains unclear. Forty synthetic distal tibiae with identical osteotomies were randomized into 4 fixation constructs: (1) two parallel unicortical cancellous screws; (2) two parallel bicortical cortical screws; (3) a contoured mini-fragment T-plate with 2 unicortical screws in the fragment and 2 bicortical screws in the shaft; and (4) a contoured mini-fragment T-plate with 2 bicortical screws in the fragment and 2 unicortical screws in the shaft. Specimens were subjected to offset axial tension loading on a servohydraulic testing system and tracked using high-resolution video. Failure was defined as 2 mm of articular displacement. Analysis of variance followed by a Tukey-Kramer post hoc test was used to assess for differences between groups, with significance defined as P<.05. The mean stiffness (±SD) values of both mini-fragment T-plate constructs (239±83 N/mm and 190±37 N/mm) and the bicortical screw construct (240±17 N/mm) were not statistically different. The mean stiffness values of both mini-fragment T-plate constructs and the bicortical screw construct were higher than that of a parallel unicortical screw construct (102±20 N/mm). Contoured T-plate constructs provide stiffer initial fixation than a unicortical cancellous screw construct. The T-plate is biomechanically equivalent to a bicortical screw construct, but may be superior in capturing small fragments of bone. [Orthopedics. 2018; 41(3):e395-e399.].

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.

An Alternate Technique of Applying Lag Screw for Fixation of Distal Fibula Fracture: Posterior to Anterior Interfragmentary Compression Screw

Ankle fractures are one of the most common lower limb fractures, representing a significant portion of the trauma workload. Marked proportion of these is isolated intraarticular lateral malleolus fractures. Anatomical reduction and rigid internal fixation using lag screw (interfragmentary screw) to provide interfragmentary compression has remained the choice of treatment in selected lateral malleolus fractures. Applying interfragmentary compression screw from anterior to the posterior surface of the fibula has been the traditional method of performing this. In this article, we describe an alternate method of applying posterior-anterior interfragmentary compression screw to the fibula fractures. We will also discuss the benefits it provides such as minimizing the chances of hardware-related peroneal tendon irritation. Further argument will focus on the mechanical benefit this will render while providing equal clinical outcome of the time tested anterior-posterior interfragmentary compression screw.

LEVELS OF EVIDENCE

Level V: Therapeutic comparison.

Radiological assessment of ankle syndesmotic reduction

INTRODUCTION

The intraoperative assessment of adequacy of syndesmotic reduction is challenging. The aim of this study was to develop a radiographic measure based on the lateral ankle view to assess both the normal and abnormal relationship between the tibia and fibula after simulated syndesmotic malreduction and to evaluate the effect on commonly used mortise measurements.

METHODS

Mortise and talar dome lateral radiographs were obtained in eight fresh-frozen cadaveric specimens before and following syndesmosis division and posterior fibular displacement of 2mm increments. Using the technique described, on the lateral radiograph the anterior fibular line ratio (AFL ratio) and posterior fibular line distance (PFL distance) were measured. Both measures were based on the anterior and posterior distal tibia articular margins and flat borders of the fibula.

RESULTS

Inter- and intraobserver reliability of the AFL ratio and PFL distance measured almost perfect agreement. In all uninjured specimens the AFL lay just anterior to the midpoint of the tibia and the PFL intersected the posterior tibia articular margin or lay just anterior to it, not posterior. At 2, 4 and 6mm of posterior fibular displacement the decrease in AFL ratio and PFL distance showed significant differences between all pairwise comparisons.

CONCLUSION

The proposed new measures of syndesmotic reduction are reproducible and capable of detecting from 2mm of sagittal fibula displacement and can be useful adjuncts in the assessment of syndesmotic reduction.