Can treatment of posterior malleolus fractures with tibio-fibular instability be usefully addressed by Bartonicek classification?

IntroductionAnkle fractures account for 4% of all fractures and treatment of those involving the Posterior Malleolus remains controversial. Clinical and radiological outcomes in a cohort of patients with Posterior Malleolus fractures conservatively treated were retrospectively evaluated; furthermore, a treatment algorithm was suggested.MethodsPatients were divided according to Bartoní?ek classification. The clinical evaluation was made with OMAS/AOFAS scores; the radiological evaluation with Van Dijk classification for post-traumatic arthritis.ResultsClinical outcome worsened with the severity of Bartoní?ek classification, but early degenerative changes were not correlated neither to the clinical outcome nor to the injury pattern. Clinical and radiological outcomes depended on the damage of the syndesmosis as articular step-offs and tibio-fibular notch involvement.DiscussionWe recommend conservative treatment for Bartoní?ek type I, type II and type III fractures, the latter when undisplaced and without tibial plafond depression. We suggest surgical treatment for type IV and displaced type III fractures.     

Posterior Locking Plate Fixation of Bartoníček Type IV Posterior Malleolar Fracture: A Focus on Die-Punch Fragment Size

Die-punch fragments refer to articular cartilage and subchondral bone embedded in cancellous bone as part of an intra-articular fracture. Bartoní?ek type IV posterior malleolar fractures with associated die-punch fragments are rare, and the appropriate surgical approach remains unclear. We determined outcomes, and the effect of die-punch fragment size on outcomes, for 32 patients with Bartoní?ek type IV posterior malleolar fractures with die-punch fragments between January 2015 and December 2017. Mean follow-up for all patients was 23.8 (range 20.0-30.0) months. At the final follow-up visit, mean ankle dorsal extension was 24.6° and plantar flexion was 40.0°; American Orthopaedic Foot and Ankle Society ankle-hindfoot score was 88.6 ± 4.3; visual analog scale weightbearing pain score was 1.5 ± 0.6; and Bargon traumatic arthritis score was 0.8 ± 0.4. There were no severe complications. We divided patients into a small-fragment (≤3 mm) group (n = 12) and large-fragment (>3 mm) group (n = 20). The Bargon scores at final follow-up were 0.5 and 1, respectively (P=.02). There were no statistically significant differences between the 2 groups for the other outcome scores at various time intervals. The posterolateral approach with distal locking plate internal fixation for Bartoní?ek type IV posterior malleolar fractures with die-punch fragments can result in excellent anatomical reduction of the collapsed articular surface and the displaced fragment from the tibial plafond, recovery of articular surface congruity, and maintenance of joint stability. Die-punch fragment size may not impact clinical and functional outcomes but may contribute to post-traumatic arthritis.     

The effect of computerised tomography on operative planning in posterior malleolus ankle fractures

BackgroundThe aim of this project was to analyse whether a CT influences surgical planning in ankle fracture involving the posterior malleolus.MethodsTwenty consecutive patients with fractures involving the posterior malleolus were retrospectively selected and had their plain radiographs and CT scan anonymised. Initially, radiographs alone were presented to nine trauma surgeons to formulate a surgical plan individually. After a minimum of 6 weeks, the same process was repeated with CT scans available.ResultsThe surgical approach for ankle fracture fixation changed in 32.7% of cases following CT scan review. A CT scan altered the decision to stabilise the posterior malleolus in 25.6% and the decision of whether to stabilise the syndesmosis in 16.6% of cases.ConclusionsThis study demonstrates that a pre-operative CT scan changes the surgical approach in 32.7% of cases and therefore we recommend use of CT scanning in this subset of ankle injuries.     

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.     

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.     

Middle-sized posterior malleolus fractures: Fixed versus non-fixed – A prospective randomized study

PurposeThis study aimed to assess the impact of fixation on functional and radiological outcomes of ankle fractures involving the posterior malleolus. We hypothesized that fixation of the posterior malleolus would be associated with improved radiological and functional outcome.MethodsA prospective randomized controlled study was planned and 40 consecutive ankle fractures involving middle-sized (10–25%) posterior fragment were included. Posterior fragments in Group 1 were not fixated while Group 2 underwent posterior malleolus fixation. The patients were evaluated both functionally and radiologically at minimum 2-years.ResultsDemographics and fracture type distributions were similar between the groups. Despite the slightly better functional outcome in Group 2, no significant functional or radiological outcome difference could be detected. Articular step-off> 1 mm was more common in Group 1 (p = 0.04) and the patients with articular step-off showed significantly worse functional outcome in all functional parameters (p < 0.05). Radiological and functional outcome parameters were positively correlated when all patients were evaluated together. Lateral radiographs caused an overestimation in the size of posterior fragment compared to CT (p < 0.001).ConclusionAlthough there was a slightly better clinical outcome in patients with fixed posterior fragments, it was not significant at short to mid-term follow-up. However, posterior fragment fixation contributed to functional outcomes by decreasing the incidence of articular step-off> 1 mm, which was found to be a negative prognostic factor.Level of evidenceLevel I; prospective randomized controlled study.     

Comparing Different Surgical Techniques for Addressing the Posterior Malleolus in Supination External Rotation Ankle Fractures and the Need for Syndesmotic Screw Fixation

Trimalleolar ankle fractures are unstable injuries with possible syndesmotic disruption. Recent data have described inherent morbidity associated with screw fixation of the syndesmosis, including the potential for malreduction, hardware irritation, and post-traumatic arthritis. The posterior malleolus is an important soft tissue attachment for the posterior inferior syndesmosis ligament. We hypothesized that fixation of a sizable posterior malleolar (PM) fracture in supination external rotation type IV (SER IV) ankle fractures would act to stabilize the syndesmosis and minimize or eliminate the need for trans-syndesmotic fixation. A retrospective review of trimalleolar ankle fractures surgically treated from October 2006 to April of 2011 was performed. A total of 143 trimalleolar ankle fractures were identified, and 97 were classified as SER IV. Of the 97 patients, 74 (76.3%) had a sizable PM fragment. Syndesmotic fixation was required in 7 of 34 (20%) and 27 of 40 (68%), respectively, when the PM was fixed versus not fixed (p = .0002). When the PM was indirectly reduced using an anterior to posterior screw, 7 of 15 patients (46.7%) required syndesmotic fixation compared with none of 19 patients when the PM fragment was fixated with direct posterior lateral plate fixation (p = .0012). Fixation of the PM fracture in SER IV ankle fractures can restore syndesmotic stability and, thus, lower the rate of syndesmotic fixation. We found that fixation of a sizable PM fragment in SER IV or equivalent injuries through posterolateral plating can eliminate the need for syndesmotic screw fixation.     

后侧腓骨钢板内固定在踝关节骨折中的应用

目的：探讨踝关节骨折治疗的新方法并评价其疗效。方法：手术治疗踝关节骨折42例,对其中资料完整的34例进行分析,男19例,女15例。根据Weber-AO分类：B型28例,C型6例。应用Baird和Jackson评分系统对其术后疗效进行评定,并将骨折类型、骨折固定方法、术后功能锻炼时间与最终功能的关系进行分析。对34例Weber-AO分型的B型及C型踝关节骨折,采用腓骨后侧钢板内固定,以避免螺钉对关节面的损伤,对同时伴有后踝骨折的病例,同时一个切口对腓骨及后踝进行固定。结果：随访时间1.2～3.2年,平均1.8年。34例中疗效为优24例,良6例,可4例,优良率为88.2%。结论：腓骨后侧钢板内固定治疗踝关节骨折,避免了螺钉对关节面的损伤,增加了螺钉的把持力,并可一个切口同时完成外踝及后踝骨折的治疗,为踝关节骨折治疗提供了一个新方法。     

Outcomes of posterior malleolar fixation in ankle fractures in a major trauma centre

AimsOngoing controversy exists over the indications and benefits of posterior malleolar fixation in ankle fractures. The aim of this pragmatic study was to evaluate the outcomes of posterior malleolar fracture fixation in ankle fractures in the setting of a major trauma centre. Our hypothesis is that posterior malleolus fixation leads to improved clinical outcomes.MethodsA total of 320 patients were identified with operatively treated ankle fractures involving a posterior malleolus component, at our institution between January 2012 and January 2018, ensuring a minimum 2 year follow-up. Of these patients, 160 had the posterior malleolus fixed as part of their surgery and 160 did not. Patient demographics, surgical details and complications were assessed. The Manchester-Oxford Foot Questionnaire (MOXFQ) was the primary patient outcome measure.ResultsFixation of the posterior malleolus was associated with a statistically significant improvement in patient outcomes. Mean MOXFQ score in the unfixed posterior malleolus group was 24.03 (0 - 62), compared to 20.10 (0 - 67) in the fixed posterior malleolus group (p = 0.04). Outcomes were worse with increasing size of posterior malleolar fragment. Metalwork-related issues were higher in the posterior malleolus fixed group (24/160 (15%) versus 10/160 (6.2%)) and re-operation rate was double.ConclusionThis study demonstrates that in the practical setting of a major trauma unit, fixation of the posterior malleolar fracture leads to improved patient outcomes but with increased metalwork risks and reoperation rates.     

The association between medial malleolar fracture geometry,injury mechanism,and syndesmotic disruption

BackgroundPrecise correlations between medial malleolar fracture geometry and fracture mechanism have not been thoroughly described. This study sought to determine the prevalence of different medial malleolar fracture types and to elucidate the association between fracture geometry and fracture mechanism.MethodsThe records of 112 medial malleolar ankle fractures were reviewed. For each fracture, the direction of the fracture line in the medial malleolus (transverse, oblique, vertical, or comminuted), the Lauge-Hansen classification, and the presence or absence of syndesmotic injury was recorded. Bivariate correlation analysis was performed to determine if correlations existed.ResultsTransverse fractures were the most prevalent type of medial malleolar fracture [n = 64 (57%)], and they correlated with supination-external rotation injuries. These were followed by oblique fractures [29 (26)], which correlated with pronation-external rotation injuries [29 (26)], and vertical fractures [7 (6)], which correlated with supination-adduction injuries [9 (8)]. Comminuted fractures [12 (11)] and pronation-abduction injuries [22 (20)] did not correlate with any other categories. Syndesmotic injuries were correlated with transverse fractures, bimalleolar fractures, and pronation-external rotation injuries.ConclusionMedial malleolar fractures can be divided into four fracture types: transverse fractures, which correlated with supination-external rotation injuries; oblique fractures, which correlated with pronation-external rotation injuries; vertical fractures, which correlated with supination-adduction injuries; and comminuted fractures, which did not correlate with a particular type of injury. Syndesmotic injury was positively correlated with transverse fractures of the medial malleolus, bimalleolar fractures, and pronation-external rotation injuries. These findings suggest that medial malleolar fracture geometry can provide valuable information for the clinician when classifying and managing ankle fractures.     

Relationship between fracture morphology of lateral malleolus and syndesmotic stability after supination-external rotation type ankle fractures

BackgroundSyndesmotic injury with supination-external rotation (SER)-type ankle fractures are well known for the serious damages to the osseous and soft tissue envelope. However, the Lauge-Hansen classification system does not provide sufficient information related to syndesmotic injury. In this study, we aimed to investigate factors for preoperative detection of syndesmotic injury according to fracture patterns in SER III and IV ankle fractures by using radiography and computed tomography (CT).MethodsAll operative SER III and IV ankle fractures treated by a single surgeon from 2009 to 2015 were enrolled in a retrospective database. Based on computed tomographic evidence and intra-operative Cotton test, stable and unstable groups of the ankle factures were divided.ResultsA total of 52 patients with SER III, 75 patients with SER IV, and 27 patients with SER IV equivalent ankle fractures were identified, with 106 in the unstable syndesmosis group (68.8%) and 48 patients in the stable syndesmosis group (31.2%). Medial space widening and fragment angle of the fibular posterior cortex were significant predictors. The cutoff values of these factors were 4.4 mm and 32.8 degrees, respectively.ConclusionsCT was superior to simple radiography in predicting syndesmotic injury at the preoperative period in SER-type III and IV. Medial space widening and fragment angle of the fibular posterior cortex, as predictive factors, showed significant correlations. In particular, sharper fragment angle of the posterior cortex indicated higher probability of instability that remained after fracture fixation.     

手术治疗涉及后踝的踝关节骨折

目的 探讨涉及后踝的踝关节骨折的手术方法及临床疗效.方法手术治疗36例涉及后踝骨折的踝关节骨折患者.结果 36例均获随访,时间12～21个月.骨折愈合时间10～16周.根据美国足与踝关节协会（AOFAS）评分：优19例,良13例,可4例,优良率为88.9%.结论 根据骨折类型选择手术方式和固定方法,切开复位内固定治疗涉及后踝的踝关节骨折,可保证踝关节获得解剖复位,最大限度地恢复踝关节功能.     

Complications after fibula intramedullary nail fixation of pilon versus ankle fractures

BackgroundIntramedullary nail (IMN) fixation of the fibula in malleolar ankle fractures has been shown to result in less wound complications then plate fixation. Therefore, IMN fibula fixation may also be associated with lower rates of wound complications when used for higher-risk pilon fractures. The purpose of this study was to compare complications of fibula IMN fixation in pilon versus malleolar ankle fractures.MethodsA retrospective cohort comparison was performed at an urban level one trauma center involving fibula fractures in 47 patients with AO/Orthopaedic Trauma Association (OTA) type 43 fractures and 48 patients with AO/OTA type 44 fractures being treated with fibula IMN fixation. Complications, fibula-specific complications, revision surgeries, and implant removals were reviewed.ResultsThere was no detectable difference in complications (27% vs. 23%, 95% confidence interval of the odds ratio (CIOR) 0.5 to 3.2), fibular-specific complications (6% vs. 10%, CIOR 0.1 to 3.5), revision surgeries (4% vs. 4%, CIOR 0.1 to 7.5), or symptomatic fibula implant removals (13% vs. 21%, CIOR 0.1 to 1.6) between pilon and ankle fracture groups, respectively. There was one (2%) fibular nonunion and one wound complication (2%) in each of the fracture groups.ConclusionFibula IMN fixation of pilon versus ankle fractures resulted in a similar number of complications. Comparative studies of fibula IMN and plate fixation are necessary to determine if the benefits of fibula IMN in ankle fractures extends to pilon fractures.Level of evidenceLevel III, retrospective cohort.     

肱骨近端解剖接骨板治疗骨质疏松型后踝骨折

目的 探讨肱骨近端解剖接骨板(anatomy of the proximal humerus plate,APHP)治疗骨质疏松型后踝骨折的临床疗效.方法 选取我院2010年1月至2013年1月的18例骨质疏松型后踝骨折患者(其中1例为螺钉内固定失败患者行二次固定),采用小腿后内侧入路,应用肱骨近端接骨板内固定治疗,术后石膏固定4周,早期分阶段行功能康复锻炼.根据美国矫形足踝协会(AOFAS)踝与后足评分标准评估治疗效果.结果 伤口均一期愈合,无伤口感染、皮肤坏死等严重并发症,随访时间为12～24个月,平均16个月.X线检查示骨折于术后6.0～16.0个月愈合,平均9.2个月;根据AOFAS踝与后足评分标准进行功能评估:优12例,良5例,中1例,优良率为94.4％.结论 肱骨近端接骨板符合胫骨远端后外侧的解剖形态,接骨板与后踝贴合良好,覆盖面积大,通过加压,使得接骨板的作用力较均匀地分散在后踝骨折块上,避免了拉力螺钉内陷、松动等并发症,效果良好.     

Untreated small posterior fragment of ankle fracture with early removal of syndesmotic screw is associated with recurrent syndesmotic instability

IntroductionThis retrospective study aimed to report outcomes of fixation of bi-malleolar or tri-malleolar fractures combined with syndesmotic injury with or without posterior malleolar fracture (PMF), and to ascertain whether syndesmotic screw removal at 6 to 8 weeks or 3 months postoperatively is more beneficial.MethodsWe retrospectively reviewed patients who received open reduction and internal fixation for bi-malleolar (without PMF) or tri-malleolar ankle fracture (with PMF) with syndesmotic injury between January 2013 and December 2017 with at least 24 months of postoperative follow-up. All patients suffered syndesmotic instabilities and were treated using a syndesmotic screw without PMF fixation. Patients with bi-malleolar fracture with syndesmotic screw removal at 6 to 8 weeks postoperatively were included in Group I, tri-malleolar fracture with syndesmotic screw removal at 6 to 8 weeks in Group II, and tri-malleolar fracture with syndesmotic screw removal at 3 months in Group III. Demographic data, clinical and radiographic outcomes were analyzed.ResultsA total of 113 patients were included (Group I, n=47; Group II, n=43; Group III, n=23). Average size of PMF was 14% in patients with tri-malleolar fractures (Groups II and III). No significant difference in ankle functional outcome among groups was observed. The recurrence rate of syndesmotic instability was 10.6% in Group I, 20.9% in Group II, and 8.7% in Group III. Although the difference in recurrence rates of syndesmotic instability among three groups was not statistically significant (P=0.264), Group II showed more interval change in tibiofibular clear space between initial postoperative radiographs and last follow-up radiographs (P=0.028) compared to the other two groups. Fracture union was achieved in all patients without screw breakage.ConclusionWe suggest that the better timing for syndesmotic screw removal is 3 months, instead of 6 to 8 weeks postoperatively, to reduce the risk of recurrence of syndesmotic instability for tri-malleolar fracture without posterior fragment fixation.Level of EvidenceLevel III- Case-control study.     

累及后踝的踝关节骨折的手术治疗

目的探讨累及后踝的踝关节骨折的损伤机制、手术方法和治疗效果。方法自2008年7月至2012年3月间,手术治疗累及后踝的踝关节骨折共42例,男30例,女12例,应用Lauge-Hansen分类,旋后外旋型21例,旋前外旋型12例,旋前外展型9例。后踝骨折根据CT分类,Ⅰ型22例,Ⅱ型12例,Ⅲ型8例。后踝骨折根据骨块大小和关节面的塌陷情况,采用后侧支撑钢板或多枚拉力螺钉固定。结果 42例均获随访,随访时间12~24个月,骨折愈合时间10~18周。根据美国足与踝关节协会(American orthopaedic foot and ankle society,AOFAS)评分,优21例,良15例,可6例,优良率为85.7%。结论累及后踝的踝关节骨折,常伴有胫骨远端关节面塌陷和踝关节后脱位或半脱位,根据骨折类型选择手术方式和固定方法,可保证踝关节获得解剖复位,最大限度恢复踝关节功能。     

内踝后丘部骨折的诊断及手术治疗

目的总结内踝后丘部骨折的诊断及手术治疗经验。方法 2008年3月-2010年11月,采用切开复位内固定治疗14例外踝和/或后踝骨折合并内踝后丘部骨折患者。男5例,女9例;年龄27～60岁,平均44.5岁。致伤原因:扭伤9例,交通事故伤3例,高处坠落伤2例。病程3～9 d,平均6.5 d。外踝骨折14例,后踝骨折10例。内踝后丘部骨折根据Lauge-Hansen分型标准分型:旋前外旋型8例,旋前外展型3例,旋后外旋型3例。结果术后切口均Ⅰ期愈合,无相关并发症发生。患者均获随访,随访时间12～24个月,平均16.8个月。X线片检查示骨折均愈合,愈合时间为2～4个月,平均2.9个月。术后14周采用下肢活动范围测量法测量患侧跖屈、背伸活动范围分别为(38.40±3.50)°及(16.30±2.41)°,与健侧(40.50±3.48)°及(17.90±2.28)°比较,差异均无统计学意义(P>0.05)。根据Olerud和Molander踝关节骨折评分标准评定踝关节功能,获优7例,良6例,一般1例。结论螺旋CT检查可显示内踝后丘部骨折,骨折后应积极手术复位坚强固定。     

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.     

The effect of minimally displaced posterior malleolar fractures on decision making in minimally displaced lateral malleolus fractures

Purpose

Despite the high incidence of cases of minimally displaced lateral or posterior malleolus ankle fractures, treatment guidelines are still an issue of controversy. The purpose of this study was to delineate treatment preferences among orthopaedic surgeons in these fractures with and without concomitant posterior malleolus fractures. We hypothesized that concomitant minimally displaced fractures of the posterior malleolus can shift treatment preference towards operative intervention.

Methods

A questionnaire-based study was conducted among orthopaedic surgeons attending the 2012 European Federation of National Associations of Orthopaedics and Traumatology Conference (EFORT) in Berlin, Germany. Treatment preferences were reported for minimally displaced lateral malleolus fractures seen on radiographs and were then compared with treatment preferences when computed tomography (CT) was added revealing a concomitant minimally displaced posterolateral fracture of the posterior malleolus.

Results

The cohort comprised 177 surgeons from all six continents. When radiographs showing a minimally displaced lateral malleolus fracture were presented, nonoperative management was indicated by 35 % (62) of participants, whereas 65 % (115) preferred operative intervention. After CT views were added showing an accompanying minimally displaced posterolateral posterior malleolus fracture, 79 % (140) suggested operative intervention and only 21 % (37) advocated nonoperative management (p = 0.03).

Conclusions

Most surgeons prefer open reduction with internal fixation for minimally displaced lateral malleolar fractures. The presence of concomitant posterior malleolus fractures in these cases shifts treatment preference further towards open reduction with internal fixation. Because the posterior malleolus fragment might not be well delineated on standard ankle radiographs, a high index of suspicion is warranted, and the use of CT should be considered in these cases.