Integrity Of Deltoid Ligament Research Articles

Biomechanical Effects of Hindfoot Alignment in Supination External Rotation Malleolar Fractures: A Human Cadaveric Model.

Pressure distribution in the ankle joint is known to be dependent on various factors, including hindfoot alignment. We seek to evaluate how hindfoot alignment affects contact pressures in the ankle joint in the setting of supination external rotation (SER) type ankle fractures. SER fractures were created in 10 human cadaver lower extremity specimens, simulating progressive stages of injury: without fracture (step 0), SER fracture and intact deltoid ligament (step 1), superficial deltoid ligament disruption (step 2), and deep deltoid ligament disruption (step 3). At each step, varus and valgus alignment was simulated by displacing the calcaneal tuberosity 7 mm medial or lateral. Each limb was axially loaded following each osteotomy at a static load of 350 N. The center of force (COF), contact area (CA), and peak contact pressure (PP) under load were measured, and radiographs of the ankle mortise were taken to analyze the medial clear space (MCS) and talar tilt (TT). The COF (5.3 mm, P = .030) and the CA (-188.4 mm2, P = .015) changed in step 3 in the valgus hindfoot alignment compared to baseline parameters, indicating the importance of deep deltoid ligament integrity in maintaining normal ankle joint contact stress in the valgus hindfoot. These changes were not seen in the setting of varus alignment (COF: 2.3 mm, P = .059; CA -121 mm2, P = .133). PP were found to not change significantly in either varus or valgus (varus: -4.9 N, P = .132; valgus: -4 N, P = .464).The MCS demonstrated widening in step 3 compared to step 2 (0.7 mm, P = .020) in both varus and valgus hindfoot. The TT increased significantly in step 3 in the valgus hindfoot (2.8 degrees, P = .020) compared to step 0. SER-IV fractures with valgus hindfoot alignment showed significant changes in pressure distribution and radiographic parameters when compared to SER-IV fractures with varus hindfoot alignment. Based on this cadaver modeling study, patients with SERIV fracture with varus hindfoot alignment and complete deltoid ligament lesion may not need fracture fixation, whereas those with valgus hindfoot alignment likely need fracture fixation.

The additional value of weight-bearing radiographs in assessing stability of isolated type B fibular fractures

IntroductionIn isolated type B fibular fractures, the decision whether to operate or treat conservatively is principally based on congruency and stability of the ankle joint. The purpose of the current study is to examine the additional diagnostic value of the weight-bearing radiograph (WBR) in assessing stability of potentially unstable type B fibular fractures. Materials and MethodsIn this retrospective cohort study, patients were selected based on who presented an isolated type B fracture of the fibula. Unstable fractures were directly planned for surgery. Other patients underwent additional weight-bearing imaging 4–7 days after initial trauma, on which definitive treatment was based. The medial clear space (MCS) was compared between the WBR and the conventional radiograph. ResultsA total of 70 patients were included in the period January 2018-December 2021. The average MCS on conventional mortise radiograph was 3.56 mm compared to 3.02 mm on the WBR(p<0.05). The superior clear space (SCS) was equal between both groups (respectively 3.12 mm and 3.08 mm, p = 0.44). All 70 patients were initially treated conservatively with immediate weight-bearing in a brace or soft cast. One patient had the need for open repair and internal fixation due to non-union. DiscussionDifferent techniques for the assessment of deep deltoid ligament integrity exist, such as the MRI, the ultrasonography and different kinds of stress test radiographs. As fractured ankles don't need direct fixation and operative treatment can be postponed, a stepped approach for the assessment of deep deltoid ligament (DDL) integrity can be of assistance in assessing ankle stability. In isolated type B fibular fractures a stepped approach, using the weight-bearing radiograph can be of additional value in assessing the stability. It is a low cost, prevents unnecessary surgery and contributes to a quick weight-bearing non-operative treatment.

Diagnostic tools to evaluate ankle instability caused by a deltoid ligament rupture in patients with supination-external rotation ankle fractures: A systematic review and meta-analysis

AimSupination-external rotation (SER) ankle fractures account for the majority of ankle fractures and can be divided into stable or unstable fractures, based on the state of the deltoid ligament. The objective of this review was to appraise the available literature concerning diagnostic tools to evaluate deltoid ligament integrity in patients with SER-type ankle fractures. MethodsA comprehensive literature search of Pubmed and Embase was performed up to December 2020. The outcome measures were sensitivity, specificity and positive and negative predictive value of the diagnostic tools. A meta-analysis was performed to obtain an overview of sensitivity, specificity and area under the curve (AUC). The methodological quality of the articles was evaluated using Quality Assessment of Diagnostic Accuracy Studies. ResultsA total of 12 studies investigating tools for deltoid ligament rupture in patients with SER-type ankle fractures were included. The present study found sensitivity (and specificity) ranges of 0.20-0.90 (and 0.38-0.97) for clinical features, Magnetic Resonance Imaging (MRI) 0.57-0.85 (and 0.81-1.00), ultrasonography 1.00 (and 0.89-1.00), Malleolar Medial Fleck Sign (MMFS) 0.25 (and 0.99), conventional ankle mortise radiography 0.33-0.57 (and 0.60-0.94), gravity stress radiography 0.71-1.00 (and 0.72-0.88) and manual stress ankle radiography 0.65-1.00 (and 0.00-0.77). The largest AUC was found for ultrasonography, followed by MMFS, gravity stress radiography and MRI. ConclusionUltrasonography and gravity stress radiography seem the most accurate diagnostic tools to evaluate deltoid ligament integrity. To strengthen this conclusion, future research should use an identical reference test to ensure comparability of results. Nevertheless, present study is of high value to close the knowledge gap about which presently available diagnostic tool is to be preferred to evaluate deltoid ligament integrity in patients with SER-type ankle fractures.

Weightbearing Radiography and MRI Findings in Ankle Fractures.

Background. Static weightbearing radiography can be used to assess stability in ankle fractures by measuring lateral talar shift (medial clear space; MCS). However, the correlation of a stable ankle joint under weightbearing load and the structural integrity of the deltoid ligament has not been shown. In this study, we assessed deltoid ligament integrity on magnetic resonance imaging (MRI) and correlated that with weightbearing and gravity stress test radiography. Methods. Thirty-four patients with supination external rotation II-IV (SER) fractures underwent MRI, weightbearing radiography, and gravity stress test. On MRI, the deep anterior and posterior tibiotalar deltoid, tibionavicular and tibiocalcaneal ligaments, as well as the syndesmosis were assessed as intact, partial rupture, or complete rupture. The MCS was measured as the distance between the lateral border of the medial malleolus and the medial border of the talus at the level of the talar dome on the mortise view. Results. Twenty-three patients suffered a deep anterior tibiotalar ligament rupture (16 partial; 7 complete) and 2 a deep posterior tibiotalar ligament tear (1 partial; 1 complete). For MCS on weightbearing radiography, no statistically significant differences were identified between any of the individual groups. With gravity stress radiography, only a complete tear of the tibiocalcaneal ligament showed a significantly higher MCS than a partial tear or intact tibiocalcaneal ligament (P < .005). No other ligament disruption showed a significant difference between the complete rupture versus intact or partial tear. Conclusion. Weightbearing radiography does not show much variation in terms of MCS even with ligamentous disruption and fibula fracture. The talus often centers itself underneath the tibia with weightbearing radiography.Levels of Evidence: Level III: Retrospective cohort study.

Diagnostic value of intraoperative tap test for acute deltoid ligament injury.

Deltoid ligament injuries appear with isolated or even no displacement of the lateral malleolus fracture which could easily lead to misdiagnosis, which frequently brings about ankle medial instability and talus shift that eventually lead to the occurrence of ankle osteoarthritis. This study is aimed to investigate the value of the tap test for assessing the integrity of the deltoid ligament intraoperatively. Ninety-two patients with malleolar fractures and possible acute deltoid ligament injury treated in our hospital from March 2013 to May 2016 were enrolled in this prospective study. The gravity stress test and tap test were performed preoperatively by three physicians independently before and after fixation of the fibula. The sensitivity, specificity, positive and negative predictive values, and false-positive and false-negative rates of both tests were determined based on medial malleolus exploration for the integrity of the deltoid ligament. The inter-observer consistency was also analyzed. Forty seven (51.1%) versus fifty two (56.5%) of the 92 patients tested positive for deltoid ligament injury according to the preoperative gravity stress test or the subsequent tap test. Forty-eight cases (52.2%) were confirmed during surgery. The sensitivity of gravity stress test was lower than that of tap test (95.8% vs 100%), and specificity of gravity stress test was the same as tap test (97.7% vs 97.7%). Between gravity stress test and tap test, the positive and negative predictive values were 97.9% vs 92.3% and 95.6% vs 100%, and the false-positive and false-negative rates were 2.3% vs 9.09% and 4.2% vs 0%, respectively. Between the two tests results, the percentage of inter-observer agreement was > 90% (kappa coefficient > 0.80). The tap test has the advantages of high sensitivity, simple operation, and less radiation exposure, suggesting that it is of high diagnostic value for assessing the integrity of the acute deltoid ligament.

Weightbearing Radiographs and stability in SER II - IV Ankle Fractures

Category: Ankle, Sports, Trauma, Radiography, Weber B Fracture Introduction/Purpose: SER lateral malleolar fractures are common. The assessment of the stability of the ankle fracture is crucial for decision making of treatment which is associated with the integrity of the deltoid ligament (SERII-III). Slight talar shift can lead to extensive decrease of tibio-talar contact area (Ramsey 1999). Several clinical tests have been proposed of which static weightbearing radiography is used to measure the lateral talar shift with the medial clear space to detect medial instability (SERIV). However, the correlation of a stable ankle joint under weightbearing load with the structural integrity of the deltoid ligament has not been shown yet which we want to investigate. Methods: 17 patients with lateral malleolar fractures were investigated who underwent an MRI and weightbearing radiography examination. In the MRI, the deep deltoid ligament was assessed as intact, partial und complete rupture. The medial clear space was measured - distance between the lateral border of the medial malleolus and the medial border of the talus at the level of the talar dome (millimeter). Results: 7 patients suffered from deep deltoid ligament rupture (4 partial; 3 complete).The medial clear space in patients with intact deep deltoid ligament was 2.96+0.41 mm in mean, in partial rupture 2.8+0.38 mm, in complete rupture 3.43+0.23 mm. When counting the complete and partial ruptures together the mean was 3.07+0.45 mm and in partial ruptures plus the intact ones 2.91+0.40 mm. Conclusion: Our results show no significant correlation between the medial clear space and the integrity of the deep deltoid ligament (figure1). A negative weightbearing radiograph does not exclude deep deltoid ligament rupture. This fact might indicate the importance of the intrinsic stability provided by the osseous contour of the highly congruent ankle joint. In our opinion, malleolar fracture with deep deltoid ligament rupture (SERIV) can therefore be treated conservatively as long as ankle stability is provided under physiological load.

Radiography in in SER II - IV Ankle Fractures

Category: Ankle, Sports, Trauma Introduction/Purpose: SER lateral malleolar fractures are common. The assessment of the stability of the ankle fracture is crucial for decision making of treatment which is associated with the integrity of the deltoid ligament (SERII-III). Slight talar shift can lead to extensive decrease of tibio-talar contact area (Ramsey 1999). Several clinical tests have been proposed of which static weightbearing radiography is used to measure the lateral talar shift with the medial clear space to detect medial instability (SERIV). However, the correlation of a stable ankle joint under weightbearing load with the structural integrity of the deltoid ligament has not been shown yet which we want to investigate. Methods: 17 patients with lateral malleolar fractures were investigated who underwent an MRI and weightbearing radiography examination. In the MRI, the deep deltoid ligament was assessed as intact, partial und complete rupture. The medial clear space was measured - distance between the lateral border of the medial malleolus and the medial border of the talus at the level of the talar dome (millimeter). Results: 7 patients suffered from deep deltoid ligament rupture (4 partial; 3 complete).The medial clear space in patients with intact deep deltoid ligament was 2.96+0.41 mm in mean, in partial rupture 2.8+0.38 mm, in complete rupture 3.43+0.23 mm. When counting the complete and partial ruptures together the mean was 3.07+0.45 mm and in partial ruptures plus the intact ones 2.91+0.40 mm. Conclusion: Our results show no significant correlation between the medial clear space and the integrity of the deep deltoid ligament (figure1). A negative weightbearing radiograph does not exclude deep deltoid ligament rupture. This fact might indicate the importance of the intrinsic stability provided by the osseous contour of the highly congruent ankle joint. In our opinion, malleolar fracture with deep deltoid ligament rupture (SERIV) can therefore be treated conservatively as long as ankle stability is provided under physiological load.

Initial Fibular Displacement as a Predictor of Medial Clear Space Widening in Weber B Ankle Fractures

Category: Ankle, Trauma Introduction/Purpose: The diagnosis of medial ankle instability in Weber B ankle fractures remains controversial. Manual stress radiographs are considered by many to be the gold standard to assess deltoid ligament integrity (Tornetta 2000). Gravity stress examinations have been shown to be equivalent (Gill 2007, Schock 2007), and also offer the advantage of causing less patient discomfort (Schock 2007). Significant fibular displacement likely serves as a surrogate for the large amount of energy required to tear the deltoid ligament. Therefore, the purpose of this study was to determine the relationship between initial fibular displacement and medial clear space widening on a gravity stress radiograph. Methods: A retrospective review was conducted of all patients with isolated Weber B ankle fractures with both initial injury radiographs and gravity stress view from August 1st, 2014 through April 1st, 2016. A total of 17 subjects were identified, age 42.6±17 years, time to GSV 4.6±5 days. On the mortise view of injury radiographs, medial clear space (MCS), superior clear space (SCS), lateral fibular displacement (LFDP) and fibular shortening (FS) were measured, and on the lateral view, anterior to posterior fibular gap (A to P FG) was measured. The gravity stress view was used to measure the medial clear space widening (MCS-W). All statistical analysis was performed using Stata (College Station, TX). T-tests were used to calculate mean and standard deviation of each group, correlation and linear regression analyses were run with each displacement variable relative to MCS-W. ROC analysis was used to determine sensitivity and specificity of the displacement variables. Results: Strong significant correlations with MCS-W were found for LFDP (0.69, p=0.003), and A to P FG (0.72, p=0.001), but not with FS (0.34, p=0.18). Linear regression analysis revealed significant ability to predict MCS-W for both LFDP (coefficient=1.12, R2=0.48, p=0.002) and A to P FG (coefficient=2.57, R2=0.52, p=0.001) but not FS (coefficient=0.67, R2=0.11, p=0.18). When LFDP and A to P FG were combined, they accounted for 65% of the variability in MCS-W (coefficient=0.70, 1.76; R2=0.65, p=0.033, p=0.018). ROC analysis for A to P FG using cutoff values of 0.75 mm, 1.0 mm, and 1.25 mm yielded SN and SP of 100% and 75%, 100% and 100%, and 67% and 100%, respectively for each cut point. Conclusion: The initial fibular displacement is a strong predictor of medial clear space widening in Weber B ankle fractures. On lateral radiographs, an anterior to posterior fibular gap greater than 1.0 mm showed a sensitivity and specificity of 100% in predicting MCS-W=5.0 mm. This provides another tool to aid clinicians in determining the integrity of the deltoid ligament and may help prevent the need for further patient discomfort with a stress view.

Gravity Stress Radiographs and the Effect of Ankle Position on Deltoid Ligament Integrity and Medial Clear Space Measurements.

External rotation and gravity stress radiographs have been described to distinguish stable supination-external rotation-II (SER-II) ankle fractures from unstable SER-IV fractures. It has been previously shown that both external rotation and gravity stress views are equivalent in their ability to diagnose deltoid ligament injury. It has also been shown that the position of the ankle influences the external rotation stress radiograph. However, no data of ankle position exist for gravity stress radiographs. Eight fresh-frozen cadaveric ankles were dissected and destabilized sequentially according to the SER mechanism of ankle fractures, starting with the anterior inferior tibiofibular ligament, distal fibula osteotomy at the level of the syndesmosis, posterior inferior tibiofibular ligament, superficial deltoid ligament, and finally the deep deltoid ligament. Fluoroscopic radiographs were taken with gravity stress views in both neutral and plantarflexion. Measurements of both dorsal and the medial clear space were taken for each stage. The difference between the dorsal and medial clear space was measured. Positive predictive value (PPV) with a medial clear space cutoff of 5 mm was 80% in plantarflexion and 72.72% in neutral with a negative predictive value (NPV) of 100% in both positions. Using a 6-mm cutoff, the PPV improved to 100% and NPV remained 100% for both neutral and plantarflexion. When the difference measurement is used, a 1.0-mm difference yielded a PPV of 72% and an NPV of 100% in both neutral and plantarflexion. With a 1.5-mm cutoff, the PPV and NPV were 100% for both positions. The position of the ankle during gravity stress radiographs does not influence the clinical effectiveness of the images. Using larger references for stability, the PPV can be improved.

The value of tap test for intraoperative diagnosis of the acute deltoid ligament injury

Objective To explore the value of the tap test for intraoperative assessment of the integrity of deltoid ligament. Methods Sixty-two consecutive patients who were suspected to have a combined deltoid ligament injury between March 2013 and August 2015 were enrolled in this prospective study. Gravity stress test was performed on those 62 cases preoperatively by three independent doctors. The diagnosis that at least two doctors agreed with was defined as a final result. After open reduction and internal fixation of fibular and posterior malleolus fracture, tap test was performed to evaluate the integrity of deltoid ligament intraoperatively. The sensitivity, specificity, positive predict value, negative predict value, false positive rate and false negative rate were calculated. The Kappa coefficient was used to determine inter-rater reliability. Results Among the 62 cases, gravity stress test before the surgery demonstrated that 47 (75.8%) of the 62 patients had a positive result, while tap test showed 52 (83.9%) cases got a positive result. Finally 48 (77.4%) cases were proved to be combined with deltoid ligament rupture by surgical exploration. Tap test had a sensitivity of 100%(48/48), a specificity of 71.4%(10/14), a positive predict value of 92.3%(48/52), a negative predict value of 100%(10/10), a false positive rate of 28.6%(4/14) and a false negative rate of zero(0/48), while gravity stress test had a sensitivity of 95.8%(46/48), a specificity of 92.9%(13/14), a positive predict value of 97.9%(46/47), a negative predict value of 86.7%(13/15), a false positive rate of 7.1%(1/14) and a false negative rate of 4.2%(2/48). The consistency between the observers and kappa coefficient of both tests were above 90% and 0.75. Conclusion Both tap test and gravity stress test had excellent inter-rater reliability. Tap test is sensitive and easy to manipulate, and allows us to reduce radiation exposure. Although its false positive rate is relatively higher than gravity stress test, it still has good application prospects in the intraoperative assessment of the integrity of the deltoid ligament. Key words: Ligaments; Wounds and injuries; Treatment outcome

Gravity Stress Radiographs and Effect of Ankle Position on Deltoid Ligament Integrity &amp; Medial Clear Space

Category: Trauma Introduction/Purpose: External rotation and gravity stress radiographs have been described to distinguish stable Supination External Rotation-II (SER-II) ankle fractures from unstable SER-IV fractures. It has been previously shown both external rotation and gravity stress views are equivalent in their ability to diagnose deltoid ligament injury. It has also been shown that the position of the ankle influences the external rotation stress radiograph. However, no data of ankle position exists for gravity stress radiographs. Methods: 8 fresh-frozen cadaveric ankles were dissected and destabilized sequentially according to the SER mechanism of ankle fractures, starting with the anterior inferior tibiofibular ligament, distal fibula osteotomy at the level of the syndesmosis, posterior inferior tibiofibular ligament, superficial deltoid ligament, and finally the deep deltoid ligament. Fluoroscopic radiographs were taken with gravity stress views in both neutral and plantarflexion. Measurements of both dorsal and the medial clear space were taken for each stage. The difference between the dorsal and medial clear space was measured. Results: Positive predictive value (PPV) with a medial clear space cut off of 5 mm was 80% in plantar flexion and 72.72% in neutral with a negative predictive value (NPV) of 100% in both positions. Using 6 mm cutoff the PPV improved to 100% and NPV remained 100% for both neutral and plantar flexion. When the difference measurement is used a 1.0 mm difference yielded a PPV of 72% and a NPV of 100% in both neutral and plantarflexion. With a 1.5 mm cutoff the PPV and NPV was 100% for both positions Conclusion: The position of the ankle during gravity stress radiographs does not influence the clinical effectiveness of the images. By using larger references for stability, the PPV can be improved.

Manual Stress Ankle Radiography Has Poor Ability to Predict Deep Deltoid Ligament Integrity in a Supination External Rotation Fracture Cohort

Stress ankle radiographs are routinely performed to determine deep deltoid ligament integrity in supination external rotation (SER) ankle fractures. However, variability is present in the published data regarding what medial clear space (MCS) value constitutes a positive result. The purposes of the present study were to evaluate the diagnostic accuracy of different MCS cutoff values and determine whether this clinical test could accurately discriminate between patients with and without a deep deltoid ligament disruption. MCS measurements were recorded for stress ankle injury radiographs in an SER ankle fracture cohort. Preoperative ankle magnetic resonance imaging studies, obtained for all patients, were then read independently by 2 musculoskeletal attending radiologists to determine deep deltoid ligament integrity. The MCS measurements were compared with the magnetic resonance imaging diagnosis using receiver operating characteristic analyses to determine the sensitivity, specificity, and optimal data-driven cutoff values. SER II-III patients demonstrated a mean stress MCS distance of 4.3 ± 0.98 mm compared with 5.8 ± 1.76 mm in the SER IV cohort (p < .001). An analysis of differing MCS positive cutoff thresholds revealed that a stress MCS of 5.0 mm maximized the combined sensitivity and specificity of the external rotation test: 65.8% sensitive and 76.5% specific. Using the receiver operating characteristic curve analysis of the MCS measurement, the calculated area under the curve was 0.77, indicating inadequate discriminative ability for diagnosing SER pattern fractures with or without a deep deltoid ligament tear. Judicious use of additional diagnostic testing in patients with a stress MCS result between 4.0 mm and 5.5 mm is warranted.

Axial Load Weightbearing Radiography in Determining Lateral Malleolus Fracture Stability: A Cadaveric Study

Ankle fractures are the most common fracture treated by orthopaedic surgeons in the United States. Isolated lateral malleolus fractures are treated nonoperatively, while associated deltoid disruption injuries are unstable and usually treated by fixation of the fracture. Various stress radiographs and MRI have been used to determine deltoid competency and the subsequent need for operative stabilization of lateral malleolus fractures. To date, no standardization of stress radiography has been performed. The aim of this study was to evaluate the ability of weightbearing ankle X-rays to determine stability and their reliability. This study sought to utilize simulated weightbearing radiography as a potential method to determine the need for lateral malleolus fixation. Twelve cadaveric ankle specimens were tested by obtaining ankle mortise radiographs for interpretation of medial clear space. Each ankle was tested with 0, 25, 36, and 50 kg of axially applied weight. The groups of measurements obtained were: intact ankles (Group A), ankles with an isolated oblique fibular osteotomy (Group B), and osteotomized ankles after complete deltoid ligament transaction (Group C). Three authors measured the medial clear space for every ankle using PACSR software. Instability of the ankle mortise was defined as medial clear space widening of greater than 2 mm from the intact ankle. An isolated lateral malleolus fracture (Group B) and a lateral malleolus fracture with an incompetent deltoid ligament (Group C) showed no statistical medial clear space widening with simulated axial weightbearing radiography when compared to intact ankles (Group A). ANOVA's between Group A and B had p < 0.001, and between Group A and C of p < 0.001. Our model did not find instability with an osteotomized fibula and a disrupted deltoid. This study suggests a weightbearing radiograph of an isolated lateral malleolus fracture cannot determine deltoid ligament integrity and thus need for fibular operative fixation.

Ultrasonography as a Diagnostic Tool in Assessing Deltoid Ligament Injury in Supination External Rotation Fractures of the Ankle

The medial deltoid ligament is the primary stabilizing structure in the ankle joint following lateral malleolar fracture. However, medial deltoid ligament ruptures are difficult to diagnose using current imaging modalities. We hypothesized that ultrasonography can be used to accurately allow early clinical assessment of ankle fracture stability, thereby negating the need to perform plain film stress views of the acutely injured ankle. This prospective study included 12 patients (age range, 18-72) with supination external rotation fractures requiring operative fixation. Following induction of anesthesia, ultrasonography examination was performed, followed by an arthrogram under fluoroscopic screening. Radiographs, ultrasonography, and arthrographic findings were compared. There was 100% correlation between ultrasonography and arthrogram findings. Ultrasonography accurately diagnosed medial deltoid rupture with a sensitivity of 100% and specificity of 100%. Plain film radiographs of the ankle had a sensitivity of 57.1% and a specificity of 60%. The difference between these was significant (χ(2)=.0091). This study demonstrates diagnostic ultrasonography to be an accurate diagnostic modality in assessing medial deltoid ligament integrity in patients with supination external rotation fractures. It offers the same sensitivity and specificity as arthrography without the need for additional invasive procedures. Its relative ease of use and lack of ionizing radiation make it a potentially useful tool, particularly in a busy trauma service.

Evaluation of the integrity of the deltoid ligament in supination external rotation ankle fractures: a systematic review of the literature

Review the literature concerning modalities to evaluate the integrity of the deltoid ligament in patients with supination external rotation ankle fractures. The electronic databases Pubmed/Medline, CINAHL and Embase were searched from 1987 to November 2007 to identify all published original studies concerning diagnostic modalities to evaluate the integrity of the deltoid ligament in adult ankle fractures. This review included nine studies involving 423 ankle fractures. Three trails investigated medial tenderness; two studies, ecchymosis; two studies, swelling; one study, an injury radiograph; six studies, a type of radiographic stress view; one study, the Lauge-Hansen classification; one study, MRI; and one article studied arthroscopy in the evaluation of the deltoid ligament integrity. Swelling, ecchymosis, medial tenderness, initial injury radiographs and the Lauge-Hansen classification are less adequate predictors of the integrity of the deltoid ligament. Manual or the less painful variant, the gravity external rotation stress radiographs are considered the gold standard. The amount of medial clear space widening indicative of a positive external rotation stress test has been somewhat variable in the literature but > or =5 mm is generally regarded as most reliable. Achieving adequate external rotation of the foot when obtaining stress radiographs is more important than positioning the ankle in the appropriate degree of ankle flexion. The amount of applied force necessary when performing an external rotation stress radiograph is not well defined and mainly determined by the patient's pain level. The indication for surgery should not be based on the absolute value of one parameter but on the combination of several parameters. If nonoperative treatment is chosen despite a positive stress radiograph, close follow-up is critical because subluxation of the ankle joint is still possible. MRI could be useful in individual cases.

Deltoid ligament integrity in lateral malleolar fractures: a comparative analysis of arthroscopic and radiographic assessments

Foot and ankle surgeons often rely on the medial clear space to evaluate competency of the deep deltoid ligament when evaluating ankle fractures. This investigation assesses the integrity of the deep deltoid ligament after lateral malleolar fracture by using direct arthroscopic visualization and medial clear-space separation on plain film radiographs. The objectives of this study were to test the reliability of medial clear-space separation and the Lauge-Hansen classification scheme in predicting deep deltoid rupture in displaced lateral malleolar fractures. The medial clear space was measured on injury radiographs of 40 patients with an isolated displaced lateral malleolar fracture who underwent open reduction and internal fixation. Injury radiographs were classified according to the Lauge-Hansen scheme. Direct arthroscopic visualization was used to evaluate the deep deltoid ligament under manual stress before fracture reduction. The mean preoperative medial clear space in patients with a deep deltoid rupture (n = 13) was 6.6 ± 2.4 mm (range, 4 to 12 mm), and in patients without a deep deltoid rupture (n = 26), it was 4.0 ± 1.0 mm (range, 2.5 to 6 mm) (P = .002, 2-sample t test). At an injury medial clear space ≥3 mm, the false positive rate for deltoid rupture was 88.5% (P = .54, Fisher’s exact test). At ≥4 mm, the false positive rate was 53.6% (P = .007). All fractures were rotational injuries according to the Lauge-Hansen system. Three fractures were not classifiable; another 3 fractures showed deltoid ligament integrity opposite the expected finding. The results indicate that, in isolated displaced fractures of the lateral malleolus, radiographic widening of the medial clear space is not a reliable indicator for deep deltoid rupture. Some fractures considered stable by the Lauge-Hansen classification may require careful scrutiny to rule out deep deltoid injury.