Arthroscopy-assisted repair of latent syndesmotic instability of the ankle

Subtle Syndesmotic Instability

Latent or subtle syndesmotic instability is defined as an injury to the syndesmosis which is not apparent on static radiographs of the ankle. Syndesmotic injuries have also been referred to as high ankle sprains. Injury to the syndesmosis typically occurs with collision sports and often involves an external rotation force to the ankle. Diagnosis can be delayed because of negative initial imaging studies. Physical examination tests including the external rotation test, proximal squeeze test, and fibular shuck test can assist in the diagnosis. Advanced imaging modalities such as MRI and weight-bearing CT have been studied and can provide prognostic indications for management, although arthroscopic stress evaluation remains the benchmark for diagnosis. Both surgical and nonsurgical management techniques have been described, which can assist patients in returning to their preinjury level of function.

Chronic syndesmotic instability - Current evidence on management

This review article discusses the current evidence on the management of chronic syndesmotic instability. Conservative treatment has a limited role, and surgical intervention is most commonly reported as the mainstay of treatment, however the literature consists of small case series and descriptions of operative techniques, and thus the evidence base for any treatment is weak. Surgical options include arthroscopic debridement alone, static fixation with cortical screws, dynamic fixation with suture-button devices, and ligamentous repair or augmentation.

Arthroscopy for Traumatic Ankle Injuries

Using ankle arthroscopy in conjunction to open reduction internal fixation of traumatic ankle injuries can play an important role in the management of these injuries by way of treating intra-articular pathologies, leading to improved patient outcomes. While a majority of these injuries are not treated with concurrent arthroscopy, its addition may lead to more prognostic information to dictate the patient's course. This article has illustrated its use in managing malleolar fractures, syndesmotic injuries, pilon fractures and pediatric ankle fractures. While additional studies may be needed to further support AORIF, it may prove to play a vital role in the future.

High-Ankle Sprain and Syndesmotic Instability: How Far Have We Come with Diagnosis and Treatment?

Probably one of the most controversial subjects in the orthopedic field is the distal tibiofibular articulation. Even though its most primary knowledge can be a matter of enormous debate, it is in the diagnosis and treatment most of the disagreements reign. Distinguishing between injury and instability remains challenging as well as an optimal clinical decision regarding surgical intervention. The last years presented technology and that was able to bring body to an already well-developed scientifical rationale. In this review article, we aim to demonstrate the current data behind syndesmotic instability in the ligament scenario, whereas using few fracture concepts.

Instability of the distal tibiofibular syndesmosis

The distal tibiofibular syndesmosis (DTFS) is more frequently injured than previously thought. Early diagnosis and appropriate treatment is essential to avoid long term complications like chronic instability, early osteoarthritis and residual pain. Management of these injuries require a complete understanding of the anatomy of DTFS, and the role played by the ligaments stabilizing the DTFS and ankle. High index of suspicion, appreciating the areas of focal tenderness and utilizing the provocative maneuvers help in early diagnosis. In pure ligamentous injuries radiographs with stress of weight bearing help to detect subtle instability. If these images are inconclusive, then further imaging with MRI, CT scan, stress examination under anesthesia, and arthroscopic examination facilitate diagnosis. An injury to syndesmosis frequently accompanies rotational fractures and all ankle fractures need to be stressed intra-operatively under fluoroscopy after fixation of the osseous components to detect syndesmotic instability. Non-operative treatment is appropriate for stable injuries. Unstable injuries should be treated operatively. Anatomic reduction of the syndesmosis is critical, and currently both trans-syndesmotic screws and suture button fixation are commonly used for syndesmotic stabilization. Chronic syndesmotic instability (CSI) requires debridement of syndesmosis, restoration of ankle mortise with or without syndesmotic stabilization. Arthrodesis of ankle is used a last resort in the presence of significant ankle arthritis. This article reviews anatomy and biomechanics of the syndesmosis, the mechanism of pure ligamentous injury and injury associated with ankle fractures, clinical, radiological and arthroscopic diagnosis and surgical treatment.

Salvage of Chronic Syndesmosis Instability: A Retrospective Review With Mid-Term Follow-Up

Malreduced syndesmotic injuries lead to poor outcomes. No consensus exists regarding preferred surgical treatment. This study aims to assess clinical and radiographic outcomes in patients undergoing distal tibiofibular arthrodesis or stabilization. Retrospective review identified patients undergoing distal tibiofibular arthrodesis or stabilization between 2003 and 2019. Surgical factors, revision surgeries, and American Orthopedic Foot and Ankle Score ankle-hindfoot scores were collected. Radiographs were independently evaluated by 4 surgeons. Seventy patients were included. Mean American Orthopedic Foot and Ankle Score scores (n = 33) improved from 48 ± 16 preoperatively to 85 ± 14 (p < .001) at a median follow-up of 31.1 months. Mean Kellgren scores (n = 47) increased from 2.1 ± 1 to 2.5 ± 1 (p < .001) and the mean medial clear space decreased from 3.2 mm ± 0.8 mm to 2.8 mm ± 0.8 mm (p <.001) with no differences between the arthrodesis and stabilization groups. Zero patients progressed to arthroplasty or fusion. Patients demonstrated significant functional improvement after distal tibiofibular arthrodesis and stabilization. Progression of arthritis, while statistically significant, was not clinically significant.

Chronic Syndesmotic Injury: Revision and Fixation With a Suture Button and a Quadricortical Screw

Background. Chronic syndesmotic injury may cause long-term pain and reduced ankle function. Today, there is no consensus about the best surgical treatment of these injuries. We present the technique and results of revision and fixation with a suture button and a quadricortical screw. Methods. Eleven patients treated for chronic syndesmotic injury were included. The patients completed questionnaires regarding ankle function, and computed tomography scans were obtained to evaluate tibiofibular distance and osteoarthritis. Complications were registered. Results. At mean 45 months follow-up, the mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score was 87 points. There were 5 complications, including 3 hardware-related pain. The tibiofibular distance was significantly reduced with surgery. Seven patients had progression of osteoarthritis. Conclusions. Even though the majority of the patients had progression of radiological signs of osteoarthritis, the functional outcome after revision and fixation with a suture button and a quadricortical screw in chronic syndesmotic ruptures is good and comparable to the results presented in other studies.Levels of Evidence: Level IV: Case series without control, technical note.

Functional outcome of fusion versus ligament reconstruction in patients with a syndesmosis injury: A narrative review

Injury to distal tibiofibular syndesmosis is commonly associated with ankle fractures. The surgical treatment especially in isolated chronic syndesmosis instability is still debated. This article has reviewed literature identified from PubMed, EMBASE and Cochrane from year 2000 onwards and compared the functional outcomes between syndesmosis fusion and ligament reconstruction based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eighteen studies were included. All the included papers described a good-to-excellent post-operative functional outcome without major complications. No significant difference between the two surgical interventions could be concluded. Further studies of better quality shall be conducted in the future.

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.

Early Protected Weightbearing After Open Reduction Internal Fixation of Ankle Fractures With Trans-syndesmotic Screws

Traditional postoperative care after open reduction internal fixation (ORIF) of unstable ankle fractures with syndesmotic instability includes non-weightbearing for 6 to 8 weeks. However, prolonged non-weightbearing may be detrimental. The goal of this case series was to assess the outcomes of early protected weightbearing after operative treatment of acute ankle fractures with syndesmotic instability requiring screw stabilization. Fifty-eight consecutive patients, treated from January 2006 to January 2013, met the inclusion criteria with a minimum follow up of 1 year. Electronic medical records and radiographs were reviewed for patient and surgical characteristics, postoperative complications, and maintenance of reduction. Patients initiated walking at an average of 10 days (range 1 to 15) postoperatively. Surgical treatment consisted of operative reduction with standard fixation devices and 1 or 2 trans-syndesmotic screws that purchased 4 cortices. All 58 patients maintained correction after surgery when allowed to weightbear early in the postoperative recovery. Five complications (8.6%) occurred in the 58 patients, which included 3 superficial infections (5.2%) and 2 cases (3.4%) of neuritis. The maintenance of reduction and low complication rate in this study support the option of early protected weightbearing after ankle fracture ORIF with trans-syndesmotic fixation.

Reconstruction of Chronic Injured Distal Tibiofibular Syndesmosis with Autogenous Tendon Graft: A Systematic Review

Background

Chronic injuries of the distal tibiofibular syndesmosis are common in patients who fail to receive adequate diagnosis and timely treatment. Reconstruction of the distal tibiofibular syndesmosis with an autogenous tendon graft in these patients is effective, although relatively rarely reported.

Purpose

To investigate clinical outcomes of syndesmosis reconstruction with an autogenous tendon graft for chronic injuries of the distal tibiofibular syndesmosis by reviewing the current literature.

Methods

An English literature search was conducted in the MEDLINE, CENTRAL, and Cochrane databases to identify published studies up to October 2017. Preset inclusion and exclusion criteria were applied to identify all eligible articles.

Results

Five studies (all with level IV evidence) that included a total of 51 patients who underwent reconstruction with an autogenous tendon graft were identified. It was reported that the symptoms were relieved postoperatively, including obviously improved functional outcomes and restoration of motions and exercise capacity. The mean American Orthopedic Foot and Ankle Society scale score of 16 patients was 53 preoperatively and 89 postoperatively. The visual analogue scale score of 14 patients decreased from 82.4 preoperatively to 12.6 postoperatively. A total of 5 (9.8%) complication cases were reported.

Conclusion

Reconstruction of the distal tibiofibular syndesmosis with an autogenous tendon for chronic syndesmosis injury showed a good therapeutic effect in terms of both subjective symptoms and objective evaluation scores. The interosseous ligament could be an appropriate reconstruction target in the treatment of chronic syndesmosis injury.

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."

Clinical outcome of distal tibiofibular arthrodesis with plate fixation for the treatment of chronic frank syndesmosis instability

BACKGROUND

Numerous treatment strategies have been reported for the treatment of chronic frank distal tibiofibular syndesmosis instability, including several small case series treated by syndesmosis arthrodesis. The aim of this study is to report the treatment of this condition using a specially contoured plate and the associated clinical outcomes.

METHODS

Over a period of 8 years, patients presented in our institution with chronic frank distal tibiofibular syndesmosis instability were eligible to participate. All patients were managed with plating and screw fixation. The average follow-up period was 58 months (range, 12-99). Clinical outcome was evaluated using the American Orthopaedic Foot & Ankle Society ankle-hindfoot score.

RESULTS

In total, 8 patients met the inclusion criteria and formed the basis of this study. All patients could tolerate full weightbearing 3 months after surgery. The mean Visual Analog Scale pain score and the American Orthopaedic Foot & Ankle Society ankle-hindfoot score were significantly improved at the last follow-up (P<0.05). All patients were satisfied with the result and 7 patients returned to sports. 4 patients had mild limitation of ankle range of motion compared with the unaffected side.

CONCLUSION

Syndesmosis arthrodesis was a feasible method for the treatment of chronic frank syndesmosis instability according to our findings. Syndesmosis arthrodesis with plate and screw stabilization is another viable option to be considered into the surgeon's armamentarium. Larger scale studies are desirable to provide further evidence of this method of treatment.

Surgical outcome in chronic syndesmotic injury: A systematic literature review

BACKGROUND

Chronic injuries of the distal tibio-fibular syndesmosis often present with non-specific clinical and radiographic findings. If chronic instability to the distal tibio-fibular syndesmosis is verified, various reconstruction options are available. The purpose of this article is to give a systematic review of current surgical treatment options in patients with chronic syndesmotic injury.

METHODS

Three major medical databases were searched from inception through December 12, 2017: PubMed, ScienceDirect, and SpringerLink. Studies were included if they were original research studies which assessed the outcome of patients treated surgically for chronic syndesmotic instability. Only studies written in English were considered. The following data were extracted from each study: number of patients and ankles included, average patients' age, gender, study design, preoperative examination, time between the initial injury and the operation, postoperative follow-up time, operative technique, complication rates, and clinical outcome. The modified Coleman Score was used to assess the methodologic quality of the included studies.

RESULTS

Seventeen (17) studies were included. All studies were retrospective or prospective case series. Each study was performed at a single center. In general, good functional outcomes and low complication rates were reported. The American Orthopaedic Foot and Ankle (AOFAS) score was most frequently used outcome tool to measure postoperative outcomes. The quality of the included studies was overall satisfactory.

CONCLUSIONS

A few studies have reported on the operative outcomes after treating chronic syndesmotic instability. Several different techniques were used to treat this problem. The quality of current studies is overall satisfactory but could be improved with larger patient numbers and prospective analysis. Recognition of this clinical entity as an identifiable and treatable cause of ankle pain requires vigilant clinical investigation.

LEVEL OF EVIDENCE

Level IV; Systematic Review of Level IV Studies.

Imaging in syndesmotic injury: a systematic literature review

OBJECTIVES

To give a systematic overview of current diagnostic imaging options for assessment of the distal tibio-fibular syndesmosis.

MATERIALS AND METHODS

A systematic literature search across the following sources was performed: PubMed, ScienceDirect, Google Scholar, and SpringerLink. Forty-two articles were included and subdivided into three groups: group one consists of studies using conventional radiographs (22 articles), group two includes studies using computed tomography (CT) scans (15 articles), and group three comprises studies using magnet resonance imaging (MRI, 9 articles).The following data were extracted: imaging modality, measurement method, number of participants and ankles included, average age of participants, sensitivity, specificity, and accuracy of the measurement technique. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was used to assess the methodological quality.

RESULTS

The three most common techniques used for assessment of the syndesmosis in conventional radiographs are the tibio-fibular clear space (TFCS), the tibio-fibular overlap (TFO), and the medial clear space (MCS). Regarding CT scans, the tibio-fibular width (axial images) was most commonly used. Most of the MRI studies used direct assessment of syndesmotic integrity. Overall, the included studies show low probability of bias and are applicable in daily practice.

CONCLUSIONS

Conventional radiographs cannot predict syndesmotic injuries reliably. CT scans outperform plain radiographs in detecting syndesmotic mal-reduction. Additionally, the syndesmotic interval can be assessed in greater detail by CT. MRI measurements achieve a sensitivity and specificity of nearly 100%; however, correlating MRI findings with patients' complaints is difficult, and utility with subtle syndesmotic instability needs further investigation. Overall, the methodological quality of these studies was satisfactory.

Reliability of measurements on lateral ankle radiographs

Background

The aims of our study were to evaluate the validation of measurement of weight-bearing lateral radiographs. Two hypotheses were tested: the measurements on the lateral radiographs are reliable, and a theoretical limit could be identified when a surgeon can “eyeball” an incongruous ankle joint on lateral radiographs.

Methods

To test the first hypothesis, 3 experienced ankle surgeons evaluated 50 normal weight-bearing lateral radiographs of patients. The measurements assessed were the tibial lateral surface angle (TLS), the distance from the center of the talar joint circle to the longitudinal axis of the tibia (x) and the displacement from the center of the talar articular joint circle to the center of the distal tibia articular joint circle (d). To test the second hypothesis, we used CAD software to create schematic diagrams on which lateral radiographs of the ankle joint were not parallel (d = 1, 2, 3, 4 mm). Five experienced ankle surgeons were asked to judge whether the ankle articular surfaces were parallel. Intraobserver reliability was determined using the intraclass correlation coefficients (ICCs) and interobserver agreement by the Kendall coefficient of concordance.

Results

First, the intraobserver reliability was high (Cronbach’s alpha >0.80) with regard to radiographic measurements according to the ICC. Significant interobserver disagreement was found (Kendall tauB, p < 0.01) using the Kendall concordance coefficient. Second, when the d-value was 4 mm, all the observers identified the incongruous ankle joint at two separate times.

Conclusions

Consultation with experienced foot and ankle surgeons and precise definitions for lateral measurement assessments do not guarantee a high level of agreement. Surgeons can observe an incongruous ankle joint on lateral radiographs when the d-value is 4 mm.

Outcomes and Return to Activity After Operative Repair of Chronic Latent Syndesmotic Instability

BACKGROUND

This study is a retrospective review of prospectively gathered data determining the postoperative outcomes of patients who underwent operative treatment to address chronic syndesmotic instability.

METHODS

The cohort is composed of 19 individuals who elected to undergo operative treatment of chronic syndesmotic instability. The operative repair consisted of arthroscopic debridement in all cases with reduction and suture button fixation of those patients who had greater than 4 mm of syndesmotic diastasis on arthroscopic evaluation. All patients had a minimum of 24 months follow-up. This study retrospectively examined the prospectively gathered preoperative and postoperative outcome scores to include a Visual Analog Scale (VAS) pain score and an American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. In addition, patients were questioned on their ability to return to their preinjury level of activity and their ability to continue running sports. Fourteen patients returned their postoperative surveys.

RESULTS

Mean AOFAS scores improved significantly from 48 to 82.7 (P = .014). Mean VAS scores improved from 6.1 to 1.0 (P = .002). Overall, 86% (12/14) of patients were able to return to running and 79% (11/14) of patients were able to return to their preinjury level of sport. Preoperative and postoperative weight-bearing ankle radiographs were reviewed to evaluate the tibiofibular clear space and overlap. The clear space measured on anteroposterior (AP) radiographs decreased from 5.4 mm to 4.6 mm (P = .005), the clear space evaluated on the mortise radiograph decreased from 4.5 mm to 3.6 mm (P = .006), and the overlap measured on the AP radiograph increased from 5.7 mm to 6.9 mm (P = .019). All radiographs were measured by a board-certified musculoskeletal radiologist.

CONCLUSION

This study presents a treatment method that can be instituted at the time of diagnosis for syndesmotic injuries with greater than 4 mm of diastasis that were treated with debridement and stabilization. The results of this treatment technique are promising, with significant improvements in subjective outcome scores and a high rate of return to running sports.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The use of arthroscopy in acute foot and ankle trauma: a review

The use of arthroscopy in the management of acute traumatic conditions of the foot and ankle has increased in recent years, primarily because of an appreciation of fracture morphology and the utility of reducing the surgical footprint. This article presents an overview of the use of this modality in foot and ankle trauma and presents an anatomical survey of the various fractures where arthroscopic assistance can be of benefit. In addition, a discussion of the seminal articles on this subject is included.

LEVEL OF EVIDENCE

Therapeutic Level IV: Review.

The lambda sign: a new radiographic indicator of latent syndesmosis instability

BACKGROUND

Latent syndesmotic instability is a common cause of chronic ankle pain. The diagnosis is not readily apparent on static imaging as the fibula remains reduced. The hypothesis of this study was that a previously undescribed novel finding on coronal MRI (lambda sign) is an independent indicator of latent syndesmosis instability. We also report on the utility of classic radiographic and physical exam findings.

METHODS

A total of 23 patients with latent syndesmotic instability diagnosed via arthroscopy (group I) were compared to a cohort of 40 patients who were found to have a stable syndesmosis during arthroscopy for unrelated conditions (group II). A retrospective chart review was performed evaluating their clinical history, preoperative physical examination, and radiologic findings. The lambda sign is a high intensity signal seen on coronal MR imaging that resembles the Greek letter lambda.

RESULTS

All of the physical exam findings tested were statistically significant. Pain at the syndesmosis had the highest sensitivity (83%), while pain reproduced with the proximal squeeze test resulted in the highest specificity (89%). The external rotation stress test had the highest positive predictive value (75%). Of the radiographic examinations performed, only the lambda sign was found to have statistical significance with a sensitivity of 75% and a specificity of 63%. The presence of a lambda sign on the MRI of patients with physical exam findings suggestive of syndesmotic pain was highly sensitive (75%) and specific (85%).

CONCLUSION

The lambda sign noted on the coronal MRI was both sensitive and specific for injuries involving greater than 2 mm of diastasis on arthroscopic stress examination of the syndesmosis. While neither the lambda sign nor any other finding on physical or radiographic examination represented an independent predictor of syndesmotic instability, the presence of a lambda sign in concert with positive physical exam findings might help health care providers determine which patients might benefit from operative intervention or referral.

LEVEL OF EVIDENCE

Level III, case control study.

Cutaneous innervation of the ankle: an anatomical study showing danger zones for ankle surgery

Three nerves innervate the skin in the foot and ankle region: the saphenous, sural, and superficial peroneal nerves. Because they are close to the medial and lateral malleoli, these nerves are at significant risk during orthopedic interventions. The aims of this study were to investigate the distal courses of the three cutaneous nerves of the ankle and to determine their exact relationships with easily identifiable bony landmarks. Ten freshly frozen and 40 embalmed lower extremities of adults were dissected. The positions of the superficial peroneal, sural, and saphenous nerves were determined using reference lines based on easily palpable osseous landmarks. The frequencies and distributions of all three nerves and their branches were converted into absolute numbers. A danger zone for each nerve was established on the basis of the distribution of crossings between the nerves and the different reference lines. Determination of the exact orientation of the nerves around the ankle should help minimize the nerve injury rate during surgical approaches in this area. Using this easily translatable new grid system, the course and danger zones of each cutaneous nerve around the ankle can be estimated clinically.

Treatment of chronic syndesmotic injury: a systematic review and meta-analysis

PURPOSE

The purpose of this study is to systematically review and meta-analyse the available literature on the treatment of chronic syndesmotic injuries of the ankle.

METHODS

A systematic review of the PubMed/MEDLINE and EMBASE databases was conducted in August 2012 utilizing the keywords (treatment OR intervention) AND (injury OR sprain OR rupture) AND (syndesmosis OR syndesmotic OR "high ankle" OR "anterior inferior tibiofibular ligament" OR AITFL OR "posterior inferior tibiofibular ligament" OR PITFL OR tibiofibular diastasis). Studies that reported the outcomes of the surgical treatment of chronic syndesmotic injury were included in our review. Chronic was defined as symptoms longer than 6 months. Meta-analysis based on random-effects models was performed to pool the rates of success for different treatment methods.

RESULTS

The search yielded 416 publications from PubMed/MEDLINE and 473 publications from EMBASE. After abstract and full-text review, 15 articles were included in this review. Treatment methods were placed into three broad surgical treatment categories: screw fixation, arthrodesis and arthroscopic debridement. The most common treatment strategy employed was screw fixation. The pooled rates of success for screw fixation, arthrodesis and arthroscopic debridement were 87.9, 79.4 and 78.7 %, respectively.

CONCLUSION

The current evidence on the treatment of chronic syndesmosis injuries in the ankle is limited to prospective and retrospective case series. The pooled success rates for screw fixation, arthrodesis and arthroscopic debridement each exceeded 78 %. Future high-level studies are required to discern the most appropriate treatment strategy(ies) for chronic syndesmotic injuries of the ankle.

The radiographic fate of the syndesmosis after trans-syndesmotic screw removal in displaced ankle fractures

The purpose of this study was to evaluate the radiographic changes of the tibiofibular position and the ankle mortise after removal of trans-syndesmotic fixation to determine if there is loss or maintenance of correction. In addition, the effect of the type of rotational injury, early weight bearing, and the number of trans-syndesmotic screws used on the integrity of the inferior tibiofibular articulation or ankle mortise after screw removal were evaluated. An analysis was conducted of 86 patients, with an unstable rotational ankle fracture requiring open reduction with syndesmosis screw stabilization. Routine radiographic parameters were measured just after open reduction and just before syndesmotic screw removal. There was a high correlation of loss of the integrity of the syndesmotic parameters after screw removal. However, the medial clear space of the ankle changed an insignificant amount, suggesting that although there appears to be some loss of maintenance, the talus did not shift laterally at the expense of a mobile syndesmosis. Ankle injuries requiring stabilization of syndesmotic instability with use of temporary trans-syndesmotic fixation achieve a stable ankle mortise after removal. Tibiofibular diastasis is commonplace upon removal of the syndesmotic hardware, but the ankle mortise remains unchanged. Based on the radiographic criteria described in this study, the postoperative change in medial clear space or tibiofibular diastasis has no bearing on fracture type, deltoid injury, or the use of 1 or 2 cortical screws. As such, other unknown mechanisms affecting the integrity of the syndesmosis after screw removal are in place.

Management of chronic disruption of the distal tibiofibular syndesmosis

Disruption of the distal tibiofibular syndesmosis is frequently accompanied by rotational ankle fracture such as pronation-external rotation and rarely occurs without ankle fracture. In such injury, not only inadequately treated or misdiagnosed cases, but also correctly diagnosed cases can possibly result in a chronic pattern which is more troublesome to treat than an acute pattern. This paper reviews anatomical and biomechanical characteristics of the distal tibiofibular joint, the mechanism of chronic disruption of the distal tibiofibular syndesmosis, radiological and arthroscopic diagnosis, and surgical treatment.