Clinical diagnosis of syndesmotic ankle instability

We studied the feasibility of clinical tests in the diagnosis of syndesmotic injury of the ankle. 9 investigators examined 12 persons twice, including 2 patients with an arthroscopically-confirmed syndesmotic injury. They sat behind a curtain that exposed only the lower legs. We found a statistically significant relation between the final arthroscopic diagnosis and the squeeze, fibula translation, Cotton, and external rotation tests as well as for limited dorsal flexion. None of the syndesmotic tests was uniformly positive in chronic syndesmotic injury. The external rotation test had the fewest false-positive results, the fibula translation test the most. The external rotation test had the smallest inter-observer variance. The physical diagnosis was missed in one fifth of all examinations. When in accordance with medical history and physical examination, positive stress tests should raise a high index of suspicion of syndesmotic instability. The final diagnosis of such instability, however, should be made by additional diagnostic imaging and/or arthroscopy.     

Distal tibial fracture post syndesmotic screw removal: an adverse complication

Fractures of the ankle are common injuries. Some ankle fractures have an associated injury to the syndesmosis, necessitating fixation with one or more screws. Generally, the overall outcome post ankle fracture is good. However, several complications have also been described. The current authors describe a distal tibial fracture following syndesmotic screw removal. A 77-year-old woman was admitted with a bimaleollar right ankle fracture. The patient underwent an emergency operation with open reduction and internal fixation. Six weeks after the surgery, the syndesmotic screw was removed without complication. The patient presented 4 weeks after removal of the screw complaining of persistent swelling and tenderness of the right ankle without a history of trauma. Radiographs showed a non-displaced distal tibial fracture around the site at which the syndesmotic screw was inserted. The distal tibial fracture was treated conservatively with a toe-to-knee cast for 6 weeks. In summary, the authors present a rare case of distal tibial fracture. Surgeons should bear this additional complication in mind.     

Predisposing factors for chronic syndesmotic instability following syndesmotic fixation in ankle fracture: Minimum 5-year follow-up outcomes

BackgroundThis study aimed to identify risk factors for chronic syndesmotic instability following syndesmotic fixation.MethodsWe performed a retrospective review of consecutive patients who had sustained ankle fractures requiring syndesmotic fixation. Patients available for a minimum 5 years of follow-up were classified into 2 groups according to the presence of syndesmotic instability. Statistical binary logistic regression analyses were performed to investigate the significance of various risk factors. Functional outcomes were assessed using the FAOS.ResultsIn total, 166 patients who met the study inclusion criteria underwent analysis. The overall postoperative instability rate was 20.5%, which was significantly affected due to BMI (p = 0.018; OR 6.72), and concomitant posterior malleolar fracture (p = 0.032, OR 2.77). The mean scores in the syndesmotic instability (SI) group were significantly lower than those in the no syndesmotic instability (NSI) group (p = 0.021).ConclusionsObesity and concomitant posterior malleolar fracture were significant risk factors for postoperative syndesmotic instability.     

Anterior-inferior tibiofibular ligament anatomical repair and augmentation versus trans-syndesmosis screw fixation for the syndesmotic instability in external-rotation type ankle fracture with posterior malleolus involvement: A prospective and comparative study

PurposeSyndesmosis injury is common in external-rotation type ankle fractures (ERAF). Trans-syndesmosis screw fixation, the gold-standard treatment, is currently controversial for its complications and biomechanical disadvantages. The purpose of this study was to introduce a new method of anatomically repairing the anterior-inferior tibiofibular ligament (AITFL) and augmentation with anchor rope system to treat the syndesmotic instability in ERAF with posterior malleolus involvement and to compare its clinical outcomes with that of trans-syndesmosis screw fixation.Methods53 ERAFs with posterior malleolus involvement received surgery, and the syndesmosis was still unstable after fracture fixation. They were randomised into screw fixation group and AITFL anatomical repair with augmentation group. Reduction quality, syndesmosis diastasis recurrence, pain (VAS score), time back to work, Olerud–Molander ankle score and range of motion (ROM) of ankle were investigated.ResultsOlerud–Molander score in AITFL repair group and screw group was 90.4 and 85.8 at 12-month follow-up (P > 0.05). Plantar flexion was 31.2° and 34.3° in repair and screw groups (P = 0.04). Mal-reduction happened in 5 cases (19.2%) in screw group while 2 cases (7.4%) in repair group. Postoperative syndesmosis re-diastasis occurred in 3 cases in screw group while zero in repair group (P > 0.05). Pain score was similar between the two groups (P > 0.05). Overall complication rate and back to work time were 26.9% and 3.7% (P = 0.04), 7.15 months and 5.26 months (P = 0.02) in screw group and repair group, respectively.ConclusionsFor syndesmotic instability in ERAF with posterior malleolus involvement, the method of AITFL anatomical repair and augmentation with anchor rope system had an equivalent functional outcome and reduction, earlier rehabilitation and less complication compared with screw fixation. It can be selected as an alternative.     

Treatment of syndesmotic disruptions of the ankle with bioabsorbable screw fixation.

BACKGROUND: Bioabsorbable implants have restricted indications because of their unique biochemical properties and their inferior biomechanical properties compared with those of conventional metallic implants. The purpose of this prospective study was to assess the efficacy of screws made of polylevolactic acid (PLLA) in the treatment of syndesmotic disruptions associated with ankle fractures and fracture-dislocations. METHODS: Thirty-three consecutive patients with a syndesmotic disruption were managed with standard metallic plate-and-screw fixation of the malleolar fracture and with 4.5-mm polylevolactic acid screws, with purchase in four cortices, for fixation of the syndesmosis. Intraoperative radiographs confirmed reduction of the syndesmosis, and all of the patients were managed with a non-weight-bearing plaster splint or brace for six weeks. Clinical and radiographic assessment and functional evaluation with use of the Olerud-Molander scoring system were performed at the time of follow-up. RESULTS: Ten patients were lost to follow-up prior to the twenty-four-month evaluation, leaving twenty-three patients with an average duration of follow-up of thirty-four months (range, twenty-four to forty-three months). All of the malleolar fractures healed in an anatomical position at an average of three months, and no postoperative displacement of the syndesmosis or widening of the medial clear space was detectable on radiographs. No episodes of osteolysis or late inflammation secondary to the hydrolyzed polylactide occurred. Nineteen patients (83%) had an excellent result, and four patients (17%) had a good result. All twenty-three patients returned to their preinjury level of work and activities of daily living. No patient had malunion, nonunion, loss of reduction, or complications attributable to the biomechanical or biochemical properties of the implants. CONCLUSIONS: Polylevolactic acid screws are effective in stabilizing disruption of the syndesmosis during healing of unstable ankle fractures. In this small series, the bioabsorbable screw was well tolerated, and there was no need for a second operation to remove it.     

The symptomatic os subfibulare. Avulsion fracture of the fibula associated with recurrent instability of the ankle

Four adults who had symptomatic instability of the ankle had an associated os subfibulare. Operative exploration revealed the ossicle to represent a non-union of an avulsion fracture of the anterior talofibular ligament. These findings suggest that an os subfibulare represents an avulsion fracture that may or may not be associated with laxity of the anterior talofibular ligament, rather than being a normal variant.     

Surgical treatment of syndesmotic diastasis: emphasis on effect of syndesmotic screw on ankle function

Fifty-two consecutive adult patients with syndesmotic diastasis (SD) were treated with closed anatomical reduction and stable fixation by a trans-syndesmotic cancellous screw. A short leg splint was prescribed for a six week postoperative period. Treatment outcomes of syndesmotic screw removal at various time points were studied and compared (group 1 at six weeks, group 2 at three months and group 3 at an average of nine months). Recurrence of SD, incidence of syndesmotic screw breakage and ankle function were compared among the three groups. Recurrence of SD occurred in 15.8% (3/19) of patients in group 1, 15.0% (3/20) in group 2 and 0% (0/13) in group 3 (p = 0.054). Breakage of the syndesmotic screw occurred in three patients within three months (group 2, 15.0%) and in two patients beyond three months (group 3, each at six and 12 months, 15.4%). None of the group 1 patients experienced screw breakage (p = 0.034). Forty-three patients (82.7%) were classified as having satisfactory outcomes. Ankle function did not significantly differ among the three groups (p = 0.191), with or without syndesmotic screw breakage (p = 0.343) and with or without SD recurrence (p = 0.218). In conclusion, restriction of daily activity for at least three months is required to prevent recurrence. Removal of the syndesmotic screw at six weeks may prevent its breakage but increases the risk of recurrence. Over an average follow-up of 19 months, SD recurrence does not lead to deterioration in ankle function.     

Triplane ankle fracture with deltoid ligament tear and syndesmotic disruption

In patients with immature skeletons, ligamentous injuries rarely accompany ankle fractures. In this article, we report about deltoid ligament tears and syndesmotic disruptions accompanying triplane ankle fractures in two children, and make recommendations as to the evaluation and treatment of children with such injuries.     

Evaluation of the syndesmotic screw in low Weber C ankle fractures

OBJECTIVE: To determine the functional and radiographic outcome of low Weber C ankle fractures and to evaluate the contribution of the syndesmotic screw in their outcome. DESIGN: Prospective evaluation of a consecutive series. SETTING: Level I trauma center. PATIENTS: Forty-five patients divided into two groups matched for age, sex, and severity of injury. Twenty-six patients were treated with open reduction, internal fixation, and a supplemental syndesmotic screw, and nineteen patients were treated without a syndesmotic screw. Minimum time to follow-up was three years. METHODS: A subjective, objective, and radiographic ankle scoring system was used. Logistical regression analysis was performed to determine whether the presence or absence of a syndesmotic screw was a predictor of a poor outcome. The likelihood ratio test was used to evaluate the significance of each variable in both univariate and multivariate analyses. RESULTS: There was no statistically significant difference between either group, either using subjective outcome criteria (p = 0.86) or in ankle range of motion (p = 0.94). Logistical regression analysis indicated that fracture dislocation could be used as a predictor of a poor outcome for either group. Inadequate reduction and advancing age were also found to be significant predictors of a poorer outcome regardless of the use of a syndesmotic screw (p = 0.003, p = 0.004). CONCLUSIONS: Judicious fixation of Weber C type injuries within five centimeters of the ankle joint, with or without a syndesmotic screw, gives similar results. Obligatory fixation of these fractures with syndesmotic screws appears to have no benefit and creates the need for an additional procedure.     

Marginal impaction associated with posterior malleolar fracture in rotational ankle injury

AimThis study aimed to introduce the circle drawing method for the evaluation of marginal impaction associated with posterior malleolar fractures (PMFs) on computed tomography (CT) images and evaluate the marginal impaction based on PMF patterns (Bartonícek classification) in rotational ankle fractures.MethodsFrom January 2014 to December 2019, A total of 299 patients were reviewed retrospectively. The circle drawing method consists of matching the articular surface of the intact tibial plafond with a best-fitted circle on the sagittal CT image. The mismatch gap between the circle and the articular surface indicates the presence of marginal impaction. To validate the circle drawing method, we assessed CT images of 60 ankles without fracture at the medial, central, and lateral parts using the new method.ResultsBased on the review of the preoperative CT scan, 153 out of 299 patients (51.2%) were identified as having PMFs. Among them, 57 patients (37.3%) had marginal impaction associated with PMFs. For small posterolateral type 2 fractures, 58% of patients (47/81) had marginal impaction, and its incidence was most frequent among all types (P<.01). For posteromedial extended type 3 fractures, 27% of patients (8/30) had marginal impaction. Extraincisural type 1 and large posterolateral triangular type 4 fractures were rarely associated with marginal impaction. Among the 180 zones of 60 ankles without fracture, 171 zones (95%) were perfectly fitted to a best-fitted circle.ConclusionsThe marginal impaction associated with PMFs is often observed in rotational ankle fractures, particularly in small posterolateral and posteromedial extended fractures.     

A biomechanical evaluation of clinical stress tests for syndesmotic ankle instability

Displacement transducers were placed across the anterior and posterior tibiofibular ligaments of 17 fresh cadaver (78.4 +/- 6.7 years old at death) lower extremities. Displacements induced by various clinical tests (squeeze, fibula translation, Cotton, external rotation, and anterior drawer) were measured with the ankle ligaments intact and after sequential sectioning of the anterior tibiofibular ligament, anterior deltoid ligament, and posterior tibiofibular ligament. None of the syndesmotic stress tests could distinguish which ligaments were sectioned. Furthermore, the small displacements measured during the stress tests (with the exception of the external rotation test) suggest it is unlikely that the displacement induced in injured syndesmoses can be clinically differentiated from normal syndesmoses. Therefore, pain, rather than increased displacement, should be considered the outcome measure of these tests.     

Mini posterior lumbar interbody fusion with presacral screw stabilization in early lumbosacral instability

Background:Surgical options for the management of early lumbosacral spondylolisthesis and degenerative disc disease with instability vary from open lumbar interbody fusion with transpedicular fixation to a variety of minimal access fusion and fixation procedures. We have used a combination of micro discectomy and axial lumbosacral interbody fusion with presacral screw fixation to treat symptomatic patients with lumbosacral spondylolisthesis or lumbosacral degenerative disc disease, which needed surgical stabilization. This study describes the above technique along with analysis of results.Results:We had nine females and three males with a mean age of 47.33 years (range 26–68 years). Postoperative assessment revealed three patients to have screw placed in anterior 1/4^th of the 1^st sacral body, in rest nine the screws were placed in the posterior 3/4^th of sacral body. At 2 years followup, eight patients (67%) showed evidence of bridging trabeculae at bone graft site and none of the patients showed evidence of instability or implant failure.Conclusion:Presacral screw fixation along with micro discectomy is an effective procedure to manage early symptomatic lumbosacral spondylolisthesis and degenerative disc disease with instability.     

The isolated posterior malleolar fracture and syndesmotic instability: A case report and review of the literature

IntroductionAnkle fractures are among the most common type of fractures in the lower extremity. A posterior malleolar fracture is frequently part of a more complex ankle fracture and only in rare cases it occurs as isolated injury. Posterior malleolar fractures often occur with associated injuries, such as a Maisonneuve fracture or with bi- or trimalleolar ligamentous injuries. Knowledge about these associated injuries is essential to prevent missed diagnoses. The aim of this article is to describe the isolated posterior malleolar fracture, the possible associated injuries, the diagnostic work-up and therapeutic consequences.Presentation of caseWe present a case of a 26-year-old male patient who sustained an isolated posterior malleolar fracture with 4.5 years follow-up.DiscussionIsolated fractures of the posterior malleolus are uncommon injuries. Diagnosis, treatment and outcome can seldom be extracted from large series. However, several cases have been described in literature, which we have summarized.ConclusionThis case report and literature review shows that isolated posterior malleolar fractures might occur as part of a more complex ankle injury, in combination with a fracture of the lower leg or after high energy trauma. Physicians should be aware of these associated injuries. Diagnostic work-up should include X-rays of the knee and lower leg and a CT scan of the ankle. If diagnosed and treated properly, isolated posterior malleolar fractures have a good long-term functional outcome.     

The effect of the syndesmotic screw on the extension capacity of the ankle joint

Summary To investigate whether, when inserting a syndesmotic screw, the foot position effects the range of motion in dorsal extension, 16 osteoligamentous lower-leg preparations were studied. The specimens were placed in a test frame where a constant dorsal extension force could be applied to the foot. The dorsal extension capacity was recorded with a syndesmotic screw inserted by a standardized technique in various plantar flexion positions. The dorsal extension capacity decreased by an average of 0.1° for every degree of increase in plantar flexion when the screw was being inserted. There was a correlation between a large decrease in range of motion and a limited dorsal extension capacity to start with. No correlation could be found between a large decrease in range of motion and a large difference in width between the anterior and posterior edges of the talar trochlea. The results suggest that the foot should be in maximal dorsal extension when a syndesmotic screw is inserted in order to decrease the risk of stiffness.     

The effect of the syndesmotic screw on the extension capacity of the ankle joint

To investigate whether, when inserting a syndesmotic screw, the foot position effects the range of motion in dorsal extention, 16 osteoligamentous lower-leg preparations were studied. The specimens were placed in a test frame where a constant dorsal extention force could be applied to the foot. The dorsal extention capacity was recorded with a syndesmotic screw inserted by a standardized technique in various plantar flexion positions. The dorsal extension capacity decreased by an average of 0.1 degree for every degree of increase in plantar flexion when the screw was being inserted. There was a correlation between a large decrease in range of motion and a limited dorsal extension capacity to start with. No correlation could be found between a large decrease in range of motion and a large difference in width between the anterior and posterior edges of the talar trochlea. The results suggest that the foot should be in maximal dorsal extension when a syndesmotic screw is inserted in order to decrease the risk of stiffness.     

Biomechanical comparison of suture-button,bioabsorbable screw,and metal screw for ankle syndesmotic repair: A meta-analysis

BackgroundTo compare biomechanically metal screw fixation to suture-button or bioabsorbable screw fixation for ankle syndesmotic injuries.MethodsA literature search of the comparison studies in Pubmed and Google Scholar was conducted. The biomechanical outcomes of interest were syndesmotic stability in the coronal, sagittal, and axial planes as well as torque and rotation at failure.ResultsA total of 11 cadaveric studies were included. In the suture-button group, coronal displacement (MD 1.72 mm, p = 0.02) and sagittal displacement (MD 2.65 mm, p = 0.0003) were increased relative to the metal screw group. In contrast, no difference was found with axial rotation (MD 0.35 degrees, p = 0.57). Bioabsorbable screws exhibited equivalent failure torque (MD ?3.04 Nm, p = 0.53) and rotation at failure (MD 3.77 degrees, p = 0.48) in comparison to metal screws.ConclusionsSuture-button provide less rigidity when compared to metal screw fixation. They afford flexible syndesmotic micromotion which may more closely resemble a physiological state and be helpful for ligament healing. Bioabsorbable screws demonstrate similar mechanical strength properties to metal screws.     

可吸收螺钉治疗踝关节骨折的临床应用

[目的]探讨可吸收螺钉（PGA-PLLA）在治疗踝关节骨折中的应用。[方法]1994年3月-2003年8月治疗踝关节骨折42例，皆行切开复位可吸收螺钉内固定术。下胫腓联合分离仍不稳定者，用可吸收螺钉横向固定。[结果]全病例得到6个月-5年3个月随访，平均2年4个月。根据美国足踝外科协会（AOFAS）制定的踝关节评定标准，优32例，良8例，可1例，差1例。优良率达95．2％。[结论]可吸收螺钉治疗踝关节骨折，具有良好的内固定特性与组织相容性，吸收完全，能早期进行功能锻炼，避免了再次手术的痛苦。