Lack of Displacement of the Fibula Is Not a Confirmation of Ankle Stability in Supination External Pattern Ankle Fractures.

OBJECTIVES: To evaluate and compare radiographic findings in supination external (SE)2 injuries versus stress (+) SE4 injuries. DESIGN: Retrospective. SETTING: Academic Level 1 trauma center. PATIENTS: The study included 350 skeletally mature patients at a single Level 1 trauma center who presented with an isolated, Lauge-Hansen type supination-external rotation pattern, Weber B lateral malleolar fracture, OTA/AO 44-B. RESULTS: We reviewed 350 patients (185 men and 165 women), 18-95 years of age (avg 45), with isolated SE pattern lateral malleolar fractures. One hundred nine had SE4 injuries [medial clear space (MCS) = 8.3 mm]. Two hundred forty-one ankles were stressed; 164 were unstable and 77 were stable (SE2). Avg MCS at presentation and on stress radiographs was 3.59 mm for the SE2 (no widening) and 3.86 mm and 5.94 mm for the stress (+) SE4 group, respectively. The fibular displacement for the SE2, stress (+) SE4, and SE4 groups was 1.5 (0-4.5), 3.5 (0-6.6), and 4.1 (0-30.5), respectively. Sixteen of the 77 (20%) SE2 and 24 of the 164 (15%) stress (+) SE4 fractures had no displacement of the fibula on the lateral view. Similarly, 53 of the 77 (68%) SE2 and 91 of the 164 (55%) stress (+) SE4 had ≤2 mm of fibular displacement Fibular displacement of ≤2 mm on the lateral radiograph corresponded with 0.69 sensitivity and only 0.37 positive predictive value for stable ankle mortise on stress examination. CONCLUSIONS: Previous work indicated that patients with an isolated SE pattern fibula fracture, a normal MCS, and ≤2 mm of fibular displacement on the lateral radiograph have a high rate of ankle stability, with a positive predictive value of approximately 97%. We were unable to confirm this finding because 15% of unstable ankles had 0 mm and 55% had ≤2 mm of fibular displacement. We conclude that stability may not be inferred from a lack of fibular displacement on the lateral view in this population of patients. If stability is to be determined, it must be tested irrespective of fibular displacement on the lateral radiograph. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

A rare type of ankle fracture: Syndesmotic rupture combined with a high fibular fracture without medial injury.

High fibular spiral fractures are usually caused by pronation-external rotation mechanism. The foot is in pronation and the talus externally rotates, causing a rupture of the medial ligaments or a fracture of the medial malleolus. With continued rotation the anterior and posterior tibiofibular ligament will rupture, and finally, the energy leaves the fibula by creating a spiral fracture from anterior superior to posterior inferior. In this article we demonstrate a type of ankle fracture with syndesmotic injury and high fibular spiral fractures without a medial component. This type of ankle fractures cannot be explained by the Lauge-Hansen classification, since it lacks injury on the medial side of the ankle, but it does have the fibular fracture pattern matching the pronation external rotation injury (anterior superior to posterior inferior fracture). We investigated the mechanism of this injury illustrated by 3 cases and postulate a theory explaining the biomechanics behind this type of injury.

[High complication rate after surgical treatment of ankle fractures]. / Høj komplikationsrate efter kirurgisk behandling af malleolfraktur.

The purpose of this study was to determine the quality and re-operation rate of the surgical treatment of ankle fractures at a large university hospital. X-rays and patient records of 137 patients surgically treated for ankle fractures were analyzed for: 1) correct classification according to Lauge-Hansen, 2) if congruity of the ankle joint was achieved, 3) selection and placement of the hardware, and 4) the surgeon's level of education. Totally 32 of 137 did not receive an optimal treatment, 11 were re-operated. There was no clear correlation between incorrect operation and the surgeon's level of education.

Evaluation of posterior malleolar fractures and the posterior pilon variant in operatively treated ankle fractures.

BACKGROUND: Substantial attention has recently been placed on fractures of the posterior malleolus. Fracture extension to the posteromedial rim ("posterior pilon variant") may result in articular incongruity and talar subluxation. Current classification systems fail to account for these fractures. The relative frequency of this fracture, its associated patient characteristics, and the reliability of its diagnosis have never been reported in such a large series. METHODS: We retrospectively identified 270 patients who met our inclusion criteria. Basic demographic data were collected. The fractures were classified according to Lauge-Hansen and AO/OTA. Additional radiographic data included whether the fracture involved the posterior malleolus and whether the fracture represented a posterior pilon variant. Univariate statistical methods, chi-square analysis, and interobserver reliability were assessed. RESULTS: The relative frequency of posterior malleolus fracture was 50%. The relative frequency of the posterior pilon variant was 20%. No significant difference was noted with respect to the frequency of posterior malleolar or posterior pilon variant between the subgroups of the AO/OTA and Lauge-Hansen classification systems when compared to the overall fracture distribution. Patients with posterior malleolar fractures and posterior pilon variants were significantly older. Females were significantly more likely than men to sustain posterior malleolar fractures and posterior pilon variants. Patients with diabetes trended toward a greater risk of both types of fractures. Interobserver reliability data revealed substantial agreement for posterior malleolar fractures and posterior pilon variants. CONCLUSION: These data represent the highest reported rate of posterior malleolar involvement in operatively treated ankle fractures and is the first to describe the percentage of the posterior pilon variant in such a large series. The interobserver reliability data demonstrate substantial agreement in identification of posterior malleolar fractures and the posterior pilon variant based on plain radiographs. Certain patient characteristics such as age, sex, and diabetes may be associated with these fractures. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

[Missed diagnosis of hiding posterior marginal fracture of ankle with pronation-external rotation type and its treatment].

OBJECTIVE: To analyze causes of missed diagnosis of hiding post-malleolar fractures in treating ankle joint fractures of pronation-external rotation type according to Lauge-Hansen classification and assess its medium-term outcomes. METHODS: Among 103 patients with ankle joint fracture of pronation-external rotation type treated from March 2002 to June 2010,9 patients were missed diagnosis,including 6 males and 3 females,with a mean age of 35.2 years old (ranged, 18 to 55 years old) . Four patients were diagnosed during operation, 2 patients were diagnosed 2 or 3 days after first surgery and 3 patients came from other hospital. All the patients were treated remedially with lag screws and lock plates internal fixation. After operation,ankle joint function was evaluated according to American Orthopaedic Foot and Ankle Society (AOFAS). RESULTS: All the 9 patients were followed up, and the duration ranged from 14 to 30 months (averaged, 17 months). No incision infection was found, and all incision healed at the first stage. At the latest follow-up, AOFAS was 83.0 +/- 4.4, the score of 4 patients diagnosed during operation was 85.0 +/- 2.9, and the score of 5 patients treated by secondary operation was 81.0 +/- 5.3. All the patients got fracture union observed by X-ray at a mean time of 2.2 months after operation. There were no complications such as internal fixation loosing, broken and vascular or nerve injuries. CONCLUSION: Ankle joint fracture of pronation-external rotation type may be combined with hiding post-malleolar fractures. So to patients with ankle joint fracture of pronation-external rotation type, lateral X-ray should be read carefully, and if necessary, CT or MRI examination should be performed. If adding lateral X-ray examination after reduction of exterior and interior ankle joint fixation, the missed diagnosis may be avoided.

Comparison of radiographic stress tests for syndesmotic instability of supination-external rotation ankle fractures: a cadaveric study.

OBJECTIVE: According to the classification of Lauge-Hansen, supination-external rotation IV (OTA 44-B) injuries should not have syndesmotic instability; yet, several studies have suggested disruption is present in up to 40% of these injuries based on stress tests. In this study, we examine various stress radiographic parameters in a cadaver model of supination-external rotation IV equivalent injury. We hypothesize that external rotation stress testing and widening of the medial clear space do not always represent syndesmotic instability. Rather, the better predictor of syndesmotic instability will be an increased tibia-fibula clear space with the lateral stress test. METHODS: Eleven fresh frozen human lower limbs were each secured into a custom frame. External rotation stress test was performed by applying an external moment of 7.5 Nm, and lateral stress test was performed by applying 100 N lateral pull at the distal fibula. True mortise radiographs were taken of intact ankles and while performing external rotation and lateral stress tests at each stage of sequentially sectioning the ankle ligaments. The deltoid ligament was sectioned first, then anterior-inferior tibiofibular ligament, posterior-inferior tibiofibular ligament, and interosseous membrane. Tibiofibular clear space and medial clear space were measured on each radiograph. RESULTS: External rotation stress test produced significant medial clear space widening when the deltoid ligaments were sectioned (P < 0.05). Lateral stress test produced no significant widening of the tibiofibular clear space until interosseous membranes were sectioned (P < 0.05). CONCLUSIONS: Lateral stress test with widening of the tibiofibular clear space is the preferred indicator of syndesmotic instability. The external rotation stress is a poor indicator of syndesmotic injury in the setting of deltoid ligament injury.

[Effectiveness of open reduction and internal fixation for Bosworth fracture].

OBJECTIVE: To explore the operative methods and effectiveness of open reduction and internal fixation for Bosworth fracture. METHODS: Between January 2005 and January 2012, 6 patients with Bosworth fractures caused by sprain were treated. There were 4 males and 2 females with an average age of 45.8 years (range, 24-73 years). The time from injury to operation was 1-5 days (mean, 1.8 days). They were all closed fractures. According to Lauge-Hansen classification, 6 cases were classified as supination-external rotation type. The surgical treatments included open reduction and internal fixation by plate and screws. RESULTS: Infection occurred in 1 case and was cured after dressing changing; primary healing of incision was obtained in the other 5 cases. Six patients were followed up 15 months on average (range, 12-24 months). The X-ray films showed fracture healing in all cases, with an average healing time of 9.5 weeks (range, 8-13 weeks). No loosening or breaking of internal fixator was observed during follow-up. The average full load-walking time was 12 weeks (range, 10-17 weeks). According to the ankle and hindfoot scale of American Orthopaedic Foot and Ankle Society (AOFAS), the average score was 89.5 (range, 81-94). CONCLUSION: For Bosworth fractures, good results can be achieved by early diagnosis, open reduction and internal fixation.

Correlation of AO and Lauge-Hansen classification systems for ankle fractures to the mechanism of injury.

BACKGROUND: Our aim was to assess whether the Lauge-Hansen (LH) and the Muller AO classification systems for ankle fractures radiographically correlate with in vivo injuries based on observed mechanism of injury. METHODS: Videos of potential study candidates were reviewed on YouTube.com. Individuals were recruited for participation if the video could be classified by injury mechanism with a high likelihood of sustaining an ankle fracture. Corresponding injury radiographs were obtained. Injury mechanism was classified using the LH system as supination/external rotation (SER), supination/adduction (SAD), pronation/external rotation (PER), or pronation/abduction (PAB). Corresponding radiographs were classified by the LH system and the AO system. RESULTS: Thirty injury videos with their corresponding radiographs were collected. Of the video clips reviewed, 16 had SAD mechanisms and 14 had PER mechanisms. There were 26 ankle fractures, 3 nonfractures, and 1 subtalar dislocation. Twelve fractures with SAD mechanisms had corresponding SAD fracture patterns. Five PER mechanisms had PER fracture patterns. Eight PER mechanisms had SER fracture patterns and 1 had SAD fracture pattern. When the AO classification was used, all 12 SAD type injuries had a 44A type fracture, whereas the 14 PER injuries resulted in nine 44B fractures, two 44C fractures, and three 43A fractures. CONCLUSION: When injury video clips of ankle fractures were matched to their corresponding radiographs, the LH system was 65% (17/26) consistent in predicting fracture patterns from the deforming injury mechanism. When the AO classification system was used, consistency was 81% (21/26). The AO classification, despite its development as a purely radiographic system, correlated with in vivo injuries, as based on observed mechanism of injury, more closely than did the LH system. LEVEL OF EVIDENCE: Level IV, case series.

[Diagnosis and surgical treatment of posterior collicular fracture of medial malleolus].

OBJECTIVE: To summary the diagnosis and surgical treatment experiences of posterior collicular fracture of medial malleolus. METHODS: Between March 2008 and November 2010, 14 patients having lateral and (or) posterior malleolus fractures with posterior collicular fracture of medial malleolus were treated with open reduction and internal fixation, including 5 males and 9 females with an average age of 44.5 years (range, 27-60 years). The causes of injuries were strain in 9 cases, traffic accident in 3 cases, and falling from height in 2 cases. The course of fracture ranged from 3 to 9 days (mean, 6.5 days). Fourteen cases were lateral malleolus fractures, 10 cases were posterior malleolus fractures. According to Lauge-Hansen classification, there were 8 cases of pronation-external rotation type, 3 cases of pronation-abduction type, and 3 cases of supination-external rotation type. RESULTS: All incisions healed by first intention with no complication. The patients were followed up 12-24 months (mean, 16.8 months). The X-ray films showed that all fractures healed from 2 to 4 months after operation (mean, 2.9 months). The range of motion (ROM) of affected ankles was (38.40 +/- 3.50) degrees of flexion and was (16.30 +/- 2.41)degrees of extension, showing no significant difference when compared with ROM of normal side [(40.50 +/- 3.48)degrees and (17.90 +/- 2.28) degrees, P > 0.05]. All patients' ankle function was evaluated by Olerud-Molander's score criteria for ankle function evaluation, the results were excellent in 7 cases, good in 6 cases, and fair in 1 case. CONCLUSION: Spiral CT plays an indispensable role in diagnosis of posterior collicular fracture of medial malleolus. Surgical reduction and rigid fixation should be performed.

Correlation of weightbearing radiographs and stability of stress positive ankle fractures.

BACKGROUND: A positive external rotation stress test has been used as an indication for operative treatment of fractures of the lateral malleolus. The objective of the current study was to ascertain the results of a protocol initially treating stress positive ankle fractures nonoperatively and utilizing weightbearing radiographs in surgical decision making. METHODS: We performed a prospective study of lateral malleolar fractures with an associated medial ligamentous injury. All patients with fractures of the lateral malleolus with medial sided symptoms and/or signs, and an intact ankle mortise underwent an external rotation stress test to confirm injury to the deltoid ligament (stress positive). Patients with a positive stress test were placed in a short-leg walking cast and seen in 7 days where weightbearing radiographs of the ankle were obtained. If the radiographs demonstrated an intact mortise, then nonoperative treatment was continued. If the weightbearing radiographs demonstrated medial clear space widening, then the patient was offered operative treatment to restore the congruency of the ankle mortise. Patients were assessed for conversion to operative treatment, complications, and functional outcome. Thirty-eight patients were enrolled in the study. Using Lauge-Hansen classification 36 (95%) were stress positive supination-external rotation fractures and 2 (5%) were stress positive pronation-external rotation fractures. Followup assessment was performed at a minimum of 6 months and averaged 12 months. RESULTS: Weightbearing radiographs at the first post-injury clinic visit had an average medial clear space of 2.9 ±0.9 mm. Three (8%) patients met our criteria for medial clear space widening and underwent operative treatment. Of these three patients, two were pronation-external rotation fracture patterns. Therefore, 3% of the supination-external rotation IV fractures, and all of the pronation-external III/IV rotation fractures ultimately required operative treatment. At final followup, the average AOFAS hindfoot score was 92 ±8.1. CONCLUSION: Ligamentous supination-external rotation Stage IV fractures with an intact mortise on static radiographs can be initially treated nonoperatively. Weightbearing radiographs should be utilized to assess congruency of the ankle mortise during an early post-injury visit. Utilizing this approach, a significant number of surgeries were avoided, and good to excellent results were obtained. From our early experience, nonoperative treatment of pronation-external rotation III/IV injuries using this protocol is not recommended.

Simplified diagnostic algorithm for Lauge-Hansen classification of ankle injuries.

Ankle injuries occur in a predictable sequence, allowing a logical understanding of their classification once the injury mechanism is recognized. The Lauge-Hansen classification system was developed on the basis of the mechanism of trauma and is useful for guiding treatment. Three radiographic views of the ankle (anteroposterior, mortise, and lateral) are necessary to classify an injury with the Lauge-Hansen system. Two additional criteria are also necessary: the position of the foot at the time of injury and the direction of the deforming force. Because understanding the mechanism of trauma is fundamental to classifying the injury, three-dimensional movies were assembled for each classification, showing the sequence of ligament rupture and bone fractures that occurs with each type of traumatic mechanism. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.322115017/-/DC1.

[Are malleolar fractures easy to treat?]. / Jsou operace malleolárních zlomenin snadné?

Malleolar fractures rank among the most frequent skeletal injuries. The majority of orthopaedic and trauma surgeons incline to surgical therapy with anatomical reposition and retention going for absolute stability. Recommended surgical techniques with screws, plates or tension-band wiring usually presents no problems for surgeons. Unsatisfactory postoperative radiological results, however, are often tolerated because revision surgery may not always have expected results. Difficulties in decision-making for right treatment are (a) the classification and right interpretation of the fracture type, (b) the question of stability and right treatment of syndesmotic injury, (c) the reconstruction of the distal fibula in length and without malrotation, (d) the question of surgical stabilization of the posterior tibial edge, and (e) the diagnostic and therapeutic approach to the medial osteoligamenteous complex. It is necessary to realise that, whatever classification has been used, injury proceeds in connected stages and can stop in each stage (Lauge-Hansen). Both supination and pronation osteoligamenteous injuries have specific patterns. It is important to analyse these patterns and put right therapeutic consequences. Included in this analysis must be the question of the right management of syndesmotic injury. It needs attention for exact reposition and retention of the distal fibula. Also, a fracture analysis of the medial complex is very important for right osteosynthesis following the principles in fracture treatment. In fractures of the anterior colliculus of the medial malleolus, the deep part of deltoid ligament can also be injured. The listed problems with their critical analyses and interpretations show that injuries of the ankle joint can be difficult to diagnose and treat. In conclusion references to these problems are critically interpreted.

Intraoperative assessment of the stability of the distal tibiofibular joint in supination-external rotation injuries of the ankle: sensitivity, specificity, and reliability of two clinical tests.

BACKGROUND: This study was designed to assess the sensitivity, specificity, and interobserver reliability of the hook test and the stress test for the intraoperative diagnosis of instability of the distal tibiofibular joint following fixation of ankle fractures resulting from supination-external rotation forces. METHODS: We conducted a prospective study of 140 patients with an unstable unilateral ankle fracture resulting from a supination-external rotation mechanism (Lauge-Hansen SE). After internal fixation of the malleolar fracture, a hook test and an external rotation stress test under fluoroscopy were performed independently by the lead surgeon and assisting surgeon, followed by a standardized 7.5-Nm external rotation stress test of each ankle under fluoroscopy. A positive stress test result was defined as a side-to-side difference of >2 mm in the tibiotalar or the tibiofibular clear space on mortise radiographs. The sensitivity and specificity of each test were calculated with use of the standardized 7.5-Nm external rotation stress test as a reference. RESULTS: Twenty-four (17%) of the 140 patients had a positive standardized 7.5-Nm external rotation stress test after internal fixation of the malleolar fracture. The hook test had a sensitivity of 0.25 (95% confidence interval, 0.12 to 0.45) and a specificity of 0.98 (95% confidence interval, 0.94 to 1.0) for the detection of the same instabilities. The external rotation stress test had a sensitivity of 0.58 (95% confidence interval, 0.39 to 0.76) and a specificity of 0.96 (95% confidence interval, 0.90 to 0.98). Both tests had excellent interobserver reliability, with 99% agreement for the hook test and 98% for the stress test. CONCLUSIONS: Interobserver agreement for the hook test and the clinical stress test was excellent, but the sensitivity of these tests was insufficient to adequately detect instability of the syndesmosis intraoperatively.

Syndesmotic fixation in supination-external rotation ankle fractures: a prospective randomized study.

BACKGROUND: This study was designed to assess whether transfixion of an unstable syndesmosis is necessary in supination-external rotation (Lauge-Hansen SE/Weber B)-type ankle fractures. METHODS: A prospective study of 140 patients with unilateral Lauge-Hansen supination-external rotation type 4 ankle fractures was done. After bony fixation, the 7.5-Nm standardized external rotation (ER) stress test for both ankles was performed under fluoroscopy. A positive stress examination was defined as a difference of more than 2 mm side-to-side in the tibiotalar or tibiofibular clear spaces on mortise radiographs. If the stress test was positive, the patient was randomized to either syndesmotic transfixion with 3.5-mm tricortical screws or no syndesmotic fixation. Clinical outcome was assessed using the Olerud-Molander scoring system, RAND 36-Item Health Survey, and Visual Analogue Scale (VAS) to measure pain and function after a minimum 1-year of followup. RESULTS: Twenty four (17%) of 140 patients had positive standardized 7.5-Nm ER stress tests after malleolar fixation. The stress view was positive three times on tibiotalar clear space, seven on tibiofibular clear space, and 14 times on both tibiotalar and tibiofibular clear spaces. There was no significant difference between the two randomization groups with regards to Olerud-Molander functional score, VAS scale measuring pain and function, or RAND 36-Item Health Survey pain or physical function at 1 year. CONCLUSION: Relevant syndesmotic injuries are rare in supination-external rotation ankle fractures, and syndesmotic transfixion with a screw did not influence the functional outcome or pain after the 1-year followup compared with no fixation.

A novel methodology for the study of injury mechanism: ankle fracture analysis using injury videos posted on YouTube.com.

PURPOSE: An inherent deficiency in the understanding of the biomechanics of fractures is the reliance on cadaveric or other nonphysiological injury models resulting from the prohibitive ethical and practical considerations of conducting injury studies in live participants. We describe a novel methodology for studying injury mechanisms using in vivo injury videos obtained from Youtube.com demonstrating injuries as they occur in real time and correlating them with the resulting injury radiographs. METHODS: Over 1000 video clips of potential ankle fractures were assessed for clear visualization of the mechanism of injury, including the foot position and deforming force. Candidate videos were selected if the mechanism of injury was classifiable by those described by Lauge-Hansen and there appeared to be a significant mechanism to likely cause fracture. X-rays were then requested from the individuals posting the video clips. Videos and x-rays were reviewed and classified using the Lauge-Hansen system in a blinded manner. The deforming mechanism in the video clips was classified as supination external rotation, supination adduction (SAD), pronation external rotation (PER), or pronation abduction. X-ray fracture patterns were similarly classified. RESULTS: Two hundred forty videos were selected and individuals posting the videos were contacted. Of 96 initial positive responses, we collected 15 videos with their corresponding radiographs. Eight had SAD-deforming trauma and seven had PER-deforming trauma as appreciated in the videos. There were 12 true ankle fractures. All five fractures judged by video to be SAD injuries resulted in a corresponding SAD pattern radiographic ankle fractures. Of the seven fractures judged by video to be PER injuries, only two resulted in PER pattern radiographic ankle fractures. Five PER injuries resulted in supination external rotation ankle fracture patterns. CONCLUSION: Our series shows that when in vivo injury videos are matched to their corresponding x-rays, the Lauge-Hansen system is only 58% overall accurate in predicting fracture patterns from deforming injury mechanism as pertaining to SAD and PER injury mechanisms. All SAD injuries correlated but only 29% of PER injuries resulted in a PER fracture pattern. This study illustrates the ethical and practical difficulties of using public access Internet YouTube videos for the study of injury dynamics. The current case series illustrates the method's potential and may lead to future research analyzing the validity of the Lauge-Hansen classification system as applied to in vivo injuries.

The use of weightbearing radiographs to assess the stability of supination-external rotation fractures of the ankle.

BACKGROUND: Isolated lateral malleolar fractures usually result from a supination-external rotation (SER) injury and may include a deltoid ligament rupture. The necessity of operative treatment is based on the recognition of a relevant medial soft-tissue disruption. Currently used tests to assess ankle stability include manual stress radiographs and gravity stress radiographs, but seem to overestimate the need for fracture fixation. METHODS: We investigated the use of weightbearing radiographs to distinguish stable and unstable isolated lateral malleolar fractures induced by the SER mechanism in 57 patients. Patients with stable fractures (SER type II according to the Lauge-Hansen classification) were treated non-operatively with varying external support. Forty-seven patients were evaluated by questionnaire and AOFAS ankle-hindfoot score. Follow-up was 18-120 months (mean 62). RESULTS: Fifty-one of fifty-seven (90%) patients were found to have stable fractures (SER type II) and were treated nonoperatively. The AOFAS score was 96.1 points on average (range 85-100) at latest follow-up. Four patients reported minor complaints. A "moderate" correlation of risk factors (i.e. smoking) to delayed bone healing was found while the correlation of varying external support (i.e. bandage, cast) to the AOFAS score and delayed bone healing was "poor". CONCLUSION: The use of weightbearing radiographs is an easy, pain-free, safe and reliable method to exclude the need for operative treatment, with excellent clinical outcome in the majority of the patients seen at latest follow-up. The delay of 3-10 days until the decision about surgical treatment is well accepted by the patients.

A new interpretation of the mechanism of ankle fracture.

BACKGROUND: Researchers have found it difficult to recreate a Lauge-Hansen supination-external rotation-type ankle fracture in experimental settings. We hypothesized that a pronation-external rotation mechanism could cause both distal, short oblique and high fibular fractures and that the fracture type would be affected by associated, laterally directed forces applied to the foot. Methlods: Twenty-three cadaver ankles were subjected to fracture loading that replicated the Lauge-Hansen pronation-external rotation mechanism with or without applying an external lateral force. In Phase I, an axial load was applied to fifteen specimens mounted on a materials testing machine. Each foot was rotated externally to failure. In Phase II, eight specimens were tested according to the Phase-I protocol, but external forces were applied laterally at the foot to increase the abduction moment at the ankle. Load and position versus time curves were recorded and were correlated with video image data to establish the sequence of failure of specific anatomic structures. RESULTS: Eight specimens tested in Phase I sustained an oblique fracture of the distal end of the fibula with both medial and posterior injuries that occurred after the fibular fracture. Increasing the external lateral force and hence the abduction moment within the ankle (Phase II) resulted in three of eight specimens sustaining a high fibular fracture with a reversed fracture line (anterosuperior to posteroinferior) and/or a comminuted high fibular fracture. The distribution of traditional pronation-external rotation-type fractures differed significantly between Phase I and Phase II (p=0.032). CONCLUSIONS: This study generated counterexamples to the Lauge-Hansen classification system by showing that a short oblique fracture of the distal end of the fibula can occur with the foot in the pronated position. Furthermore, a high fibular fracture was recreated by increasing the abduction moment at the ankle.

[Treatment of syndesmosis diastasis with screw fixation in ankle fractures].

OBJECTIVE: To explore the operative method for the treatment of syndesmosis injury in ankle fractures. METHODS: A retrospective study was done on 21 ankles of 20 patients included male 11 and female 9;the range of age were from 27 to 52 years with an average of 36 years) with syndesmosis injury in closed ankle fractures from September 2005 to December 2007. All patients with ankle fractures and syndesmosis injury were diagnosed by the history, physical examination and radiology, then treated with open reduction, internal fixation, and syndesmotic stabilization with a three-cortices syndesmotic screw according to the Lauge-Hansen classification system. Radiological evaluation comprised tibiofibular overlap, total clear space and medial clear space. The clinical effects were evaluated according to modified Baird-Jackson standard. RESULTS: All patients were followed up from 1.0 to 2.2 years with an average of 1.3 years. Radiographic measurements were detailed as follows: tibiofibular overlap averaged (0.46 +/- 3.56) mm in preoperative and (7.14 +/- 0.62) mm in postoperative; mean total clear space (5.69 +/-0.88) mm in preoperative and (3.28 +/- 0.39) mm in postoperative; medial clear space averaged (5.67 +/- 1.23) mm in preoperative and (3.12 +/- 0.33) mm in postoperative; tibiofibular overlap in mortise view averaged (-0.87 +/- 0.96) mm in preoperative and (2.91 +/- 0.30) mm in postoperative. There was significant difference above data between preoperative and postoperative (P < 0.01). Four cases were confirmed minor tibiofibular diastasis through CT scans during postoperative. The modified Baird-Jackson scoring was from 62 to 98 scores with an average of (86.24 +/- 13.26) score at the final review. Of them, 13 ankles had not pain; 16 ankles reported no instability complaints; 11 ankles gained normal walking ability; 8 ankles could run normally; 11 ankles could return work without any restrictions. Activity of ankle in dorsiflexion, plantar flexion, inversion and eversion were respectively (21.05 +/- 5.00) degrees, (33.57 +/- 5.76) degrees, (19.48 +/- 4.57) degrees and (24.05 +/- 4.86) degrees. Three cases had radiological and clinical manifestations of osteoarthritis, but no breakage of syndesmotic screw in all cases. There were excellent results in 12 cases, good in 2, fair in 4, poor in 3. CONCLUSION: The treatment for the syndesmosis diastasis with a three-cortices screw fixation in ankle fractures is effective. Good functional outcome can be obtained with anatomical restoration of the tibiofibular syndesmosis. The repair of deltoid ligament is important for stability of the lower tibiofibular syndesmosis. Removal of the screw before weight loading should be performed to avoid possible screw breakage.

Ultrasonographic examination of the deltoid ligament in bimalleolar equivalent fractures.

BACKGROUND: Lauge-Hansen supination-external rotation Stage IV ankle injuries may simulate a Stage II or Stage III injury radiographically if the medial disruption occurred through the deltoid ligament instead of the medial malleolus, making it difficult to determine whether an operation is indicated. MATERIALS AND METHODS: Seventeen patients presented with radiographically isolated lateral malleolar fractures at the syndesmotic level. They were examined with ultrasonography for evaluation of the integrity of the deltoid ligament. Patients in whom ultrasonography showed complete rupture of the deltoid ligament received operative fixation of the ankle fracture, with exploration and repair of the deltoid ligament at the same time. Patients without complete rupture of the deltoid ligament were treated conservatively with a short leg cast for 6 weeks followed by an ankle brace for another 6 weeks. Nine male and six female patients completed the final clinical and radiographic evaluations. RESULTS: Ultrasonography showed complete rupture of the deltoid ligament in six patients. Exploration of the deltoid ligaments confirmed the sonographic findings in all these patients. In the remaining nine patients, the deltoid ligaments were not completely ruptured on ultrasound. These fractures were treated conservatively, and all healed uneventfully. All the 15 patients had good or fair results on the final evaluation. CONCLUSION: Ultrasonography is a convenient and accurate diagnostic tool to differentiate unstable bimalleolar-equivalent ankle fractures from an isolated lateral malleolar fracture. Thus, it can be helpful in the decision process for the treatment of choice for different fracture patterns.