Comparison of the direct and indirect reduction techniques during the surgical management of posterior malleolar fractures

Traditional postero-medial ankle approach for Bartonícek type III in Volkmann Fractures: Is it useful?

INTRODUCTION

There is evidence that the presence of a posterior malleolus fracture (PMF) worsens the prognosis of ankle fractures, making conservative treatment a poor choice. PMFs include a heterogeneous group of bone injury patterns that are sometimes associated to medial malleolus extensions, as well as fibula fractures or syndesmotic damage. This requires the surgeon to be well-versed in anatomy to choose the appropriate surgical approach. This study examines the relationship between the visualization of the distal posterior tibial surface through a Traditional Postero-Medial (TPM) approach in a simulated fracture pattern equivalent to Bartonícek type III fractures previously studied with axial CT images.

METHODS

This is an experimental analytical cross-sectional anatomical study. Twenty fresh-frozen adult cadaveric ankle/foot specimens preserved at - 27 ºC at the University of Barcelona School of Medicine were examined. The traditional posteromedial approach was performed for each specimen, then anatomical measurements were performed. Subsequently, a Bartonícek type III fracture pattern was designed and generated for each of them. Finally, the anatomical view was correlated with axial CT images for each one and the fracture pattern was assessed. Measurements of Anatomical Visualization Surface (AVS), Total width of the Posterior M. (TWPM), Imaging Visualization Surface (IVS) and the Total Imaging Viewing Surface (TIVS) were recorded. Univariate and bivariate analysis was performed. The mean, standard deviation (SD), minimum and maximum values were calculated. The Intraclass Correlation Coefficient (ICC) was calculated.

RESULTS

Of the 20 specimens, 9 were female and 11 male, with 8 right and 12 left specimens, aged between 65 and 95 years. The average Anatomical Visualization Surface (AVS) was 24.1 ± 7.49 mm. The average of the total width of the posterior muscle (TWPM) was 30.55 ± 7.19 mm. While the average visualization was 77 ± 11 %. The average Imaging Visualization Surface was 30.23 ± 6.1 mm. The average Total Imaging Visualization Surface was 37.53 ± 3.45 mm. While the average of visualization in CT was 80 ± 11 %. A degree of agreement (CCI) was obtained with a value of 0.667 CI 95 % (0.1773-0.8672). That is, the CCI is considered good (CCI value between 0.4 and 0.75).

CONCLUSION

The TPM approach is a valid alternative for surgical access and visualization of the PM, including complex Bartonícek type III fractures. The TPM approach achieves axial visualization of the distal posterior tibial plafond of 77 ± 11 %.

Morphology of occult posterior malleolus fractures associated with tibial shaft fractures

Aims

Occult posterior malleolar fractures (PMFs) associated with tibial shaft fractures are thought to occur most commonly in spiral fracture types of the tibia. We hypothesize that tibial diaphyseal fracture patterns would be associated with certain PMFs, highlighting the pathomechanics of the injury.

Methods

A retrospective review was performed on data collected between 1 January 2013 and 9 November 2020. The inclusion criteria were patients aged over 16 years with a diaphyseal tibial fracture who had undergone a CT of the affected lower limb. The Mason and Molloy posterior malleolar fracture classification system was used to describe the morphology of the PMFs.

Results

There were 764 diaphyseal fractures identified. Of these, 442 met the inclusion criteria. A total of 107patients (24.21%) had PMF extensions. The classification of the PMFs according to Mason and Molloy revealed eight type 1 fractures (7.48%), 60 type 2A (56.07%), six type 2B (5.61%), and 33 type 3 fractures (30.84%). The most common PMF seen in this study was the minor rotational pilon (type 2A). PMFs generally occur in combination with spiral diaphyseal fractures (42A1, 42B1, 42C1, and 43A1). The majority of PMFs were undisplaced pre-surgical intervention. Only the 2B subtype (major rotational pilon) had a significant association with fracture displacement.

Conclusion

This study highlighted an association between spiral tibial shaft fractures and type 2A posterior malleolus fractures. Unlike the PM fractures of the ankle, the majority of PM fractures associated with tibia fractures are undisplaced. We theorize that unlike the force transmission in ankle fractures, where the rotational force is in the axial plane in a distal-proximal direction, in the PM fractures related to tibia fractures, the rotational force in the axial plane progresses from proximal-distal. Therefore, the force transmission which exits posteriorly, finally dissipates the force and is thus unlikely to displace.

Open reduction and fixation does not improve short-term outcome of medium-sized posterior fragments in AO type B ankle fractures: one-year results of the POSTFIX randomized controlled trial

Aims

Guidelines for treatment of posterior malleolar fragments (PMFs) in trimalleolar fractures are scarce, mainly based on retrospective studies, and show varying advice. The need for fixation of smaller (< 25%) PMFs remains particularly controversial. This study aims to evaluate the superiority of fixation of medium-sized PMFs versus no fixation of the fragment.

Methods

A multicentre randomized controlled trial was conducted between January 2014 and January 2022 in two Dutch level 1 trauma centres (protocol registration: NCT02596529). Patients presenting with an AO-44-B3 fracture with a medium-sized (5% to 25%) PMF were 1:1 randomized online between open reduction and internal fixation (ORIF) (FIX) versus no fixation (NO-FIX) of the fragment. A total of 41 patients were allocated online to FIX via the posterolateral approach and 40 patients to NO-FIX. The primary outcome was functionality measured by the American Academy of Orthopaedic Surgeons (AAOS) questionnaire one year postoperatively. Secondary outcomes were osteoarthritis (OA) measured on radiographs and the Olerud and Molander ankle score, visual analogue scale pain, and EuroQol five-dimension questionnaire during follow-up. Quality of reduction was assessed by step-off on postoperative CT scan and radiograph. Complications were recorded.

Results

After one-year follow-up, no difference (p = 0.141) in AAOS was found after FIX (median 90 (IQR 68 to 95)) and NO-FIX (median 93 (IQR 85 to 97)). OA (≥ grade 2) was present in four (17%) of the cases after FIX and five (20%) after NO-FIX (p = 0.763). After one year, median pain scores were 20 (IQR 5 to 40) versus 10 (IQR 5 to 25) (p = 0.032), and perceived general median health scores were 80 (IQR 60 to 89) versus 83 (IQR 71 to 90) (p = 0.596) after FIX and NO-FIX, respectively. Postoperative step-off > 1 mm on CT scan was present in 56% after FIX versus 71% after NO-FIX (p = 0.193). Complication rates were 18% versus 5% (p = 0.071) after FIX and NO-FIX, respectively.

Conclusion

ORIF of medium-sized posterior fragments in AO type B trimalleolar fractures does not prompt superior functional or radiological results after one-year follow-up. Longer follow-up is needed to evaluate intermediate or long-term effects.

Treatment Strategy for Posterior Malleolar Fractures: Different Operative Strategies Are Needed for Each Morphological Type

Background: The operative indication for posterior malleolar fracture (PMF) remains controversial. This study aimed to assess the midterm outcomes of PMF treatment for developing a treatment strategy for each morphological type. Methods: In this retrospective analysis, patients undergoing operative treatment for an unstable ankle fracture involving PMF were included after at least 3 years of follow-up. PMFs were classified by fracture morphology according to the Haraguchi classification. This study divided the entire cohort into three independent populations based on the types of PMF. For each population, patients were further categorized into two groups depending on whether PMF was surgically fixed or not, and comparisons were made between these two groups. Demographic data, functional and radiographical outcomes were compared between two groups in each of the three populations. Results: With a total of 472 patients, the mean patient age was 45.8 years, and the mean follow-up was 51 months. For type 1 fracture, a total of 237 cases were found. Quality of reduction by CT (QRC) was mostly good in both groups (83.6% vs. 83.3% in the non-fixation vs. fixation group, respectively, p = 0.269). Functional and radiological outcomes between both groups showed no significant difference. For type 2 PMFs, a total of 199 cases were found, and QRC was significantly different between the two groups (good grade, 5.4% vs. 60.7% in the non-fixation vs. fixation group, respectively, p < 0.001). The radiological and clinical outcomes of the PMF fixation group were statistically superior to those of the non-fixation group (both p < 0.001). For type 3 fractures, a total of 36 cases were found. In all the cases in this group, surgical fixation of PMF was not performed. Only the syndesmosis instability was analyzed as a viable factor to be considered for achieving favorable surgical outcomes. PMF fixation group showed significantly more postoperative complications (24.4% vs. 40.4%, non-fixation vs. fixation, respectively, p < 0.001). Major complications in the fixation group were deep wound infection (6.8%), superficial peroneal nerve injury (6.8%), and hallux flexion deficit (5.0%). Conclusions: Different treatment strategies seem to be required for each PMF morphological subtype. Further studies with more detailed designs for each PMFs are warranted for more clinically related results that are helpful for making practical surgical decisions.

The effects of intercalary fragments at the posterior malleolus on ankle joint pressure distribution - a biomechanical cadaveric study

INTRODUCTION

With the increased use of computed tomography scans in cases with trimalleolar ankle fractures, bone fragments between the posterior malleolus and the rest of the articular surface tibial plafond surface - described as intercalary fragments (ICFs) - can be recognized. The aim of this study was to determine the ICF size threshold for a significant change in the pressure distribution at the ankle joint, having a considerable impact on the remaining cartilage of the joint.

DESIGN AND METHODS

Eight human cadaveric lower legs were used, and a posterior malleolus Bartoniček/Rammelt II fracture was created with sequential 2 mm, 4 mm, 6 mm, and 8 mm ICFs. The posterior malleolus was fixed with a 3.5 mm one-third tube buttress plate and each specimen was mounted in a custom-made frame for axial loading under 700 N in neutral position, 30° plantar flexion, and 30° dorsiflexion of the foot. Using electronic foil sensors, pressure measurements were performed to define the contact area, centre of force, and peak pressure at the ankle joint in loaded condition.

RESULTS

Compared to the situation without ICF, contact area decreased significantly after 4 mm, 6 mm and 8 mm ICFs. Anteroposterior center of force shift was significant after 6 mm and 8 mm ICFs. Mediolateral center of force shift was significant after 2 mm, 4 mm, 6 mm and 8 mm ICFs.

CONCLUSION

Posterolateral defects of the tibial plafond alter ankle joint pressure characteristics. Regardless of the direction of ankle joint flexion, increasing the ICF defect size results in decreased contact area, increased mediolateral center of force migration and higher peak joint forces. Malreduction or removal of ICFs larger than 2 mm should be avoided to preserve physiological ankle pressure characteristics.

Comparison between anterior-to-posterior screw fixation versus posterolateral approach plate fixation for posterior malleous fracture: A systematic review and meta-analysis

PURPOSE

There are two main surgical fixation methods for the posterior malleolar fractures (PMFs), the anterior-to-posterior (AP) screws or via the posterolateral (PL) approach utilizing a buttress plate. This review aims to compare the clinical outcome between the AP screw fixation and the PL plate fixation for treating PMFs.

METHODS

We searched all relevant publications about PMFs treated with AP screws or PL plates through electronic databases including the PubMed, the Cochrane Library, the Embase, the Wiley online library and the Web of Science. The meta-analysis was conducted to evaluated clinical outcomes including reduction quality, post-operative function and complications.

RESULTS

Six studies (one single randomized controlled trial and five retrospective cohort studies) were enrolled. 172 patients underwent AP screw fixation and 214 patients underwent PL plate fixation with a total of 386 patients (169 males and 217 females). The PL plating group yielded better AOFAS scores(MD = 6.97, 95 % CI=[4.68, 9.27], P＜0.00001, I2 =0 %) and was more likely to achieve excellent anatomical reduction(OR=5.49, 95 % CI=[1.06, 28.42], P = 0.04, I2 =80 %). No differences were found in the bad reduction quality, incidences of complications (arthritis, neuralgia, superficial wound healing problems and implant failure), the walking VAS scores and the dorsiflexion restriction degrees.

CONCLUSION

We suggest that the PL plate fixation method has the clinical benefit of achieving anatomical reduction and better AOFAS scores over the AP screw fixation for treating PMFs. No differences were found in the incidences of complications ( arthritis, neuralgia, superficial wound healing problems and implant failure), the walking VAS scores and the dorsiflexion restriction degrees. The posterior approach and the direct reduction are recommended for the treatment of the PMFs.

LEVEL OF CONFIDENCE

Ⅱb.

A Comprehensive Review of Recent Trends in Posterior Malleolus Fracture Management

Posterior malleolus fractures (PMFs) are challenging injuries around the ankle that can lead to poor clinical outcomes as they can compromise ankle stability. Although there has been an evolution in the principles of management of PMFs, their optimal treatment remains controversial. This review article aims to provide an in-depth account of the management of PMF, thereby providing a better understanding of these complex cases hence resulting in improving patient outcomes.

Comparison of plate versus screw internal fixation in the treatment of posterior malleolar fracture: A systematic review and meta-analysis

BACKGROUND

Treatment of posterior malleolar fracture with plate or screw fixation is still controversial. Plate fixation is considered to have better stability but more soft tissue damage; screw fixation is less invasive and may yields lesser blood loss and surgery time. We conducted this meta-analysis to explore intraoperative and postoperative efficacy between plate and screw fixation in posterior malleolar fractured patients.

METHODS

PubMed, Cochrane, Embase, Scopus and Chinese National Knowledge Infrastructure databases were searched in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Random-effects model and 95% confidence intervals was used. The outcomes of interest were surgery time, blood loss, length of hospital stay, American Orthopedic Foot and Ankle Score (AOFAS), bone healing time, full weight bearing time, off bed ambulation time, Visual Analogue Scale (VAS), complication rate, and rate of use of syndesmosis screw etc. RESULTS: One randomized clinical trial and fifty-two retrospective cohort studies with a total of 3757 patients (1956 in screw group and 1801 in plate group) were included in the systematic review. Compared to screw group, plate group yielded significantly longer surgery time, more intraoperative blood loss, but shorter length of hospital stay, better AOFAS, better Baird Jackson score, better AOFAS and Baird Jackson excellent-good rate, shorter bone healing time, shorter time enabling full weight bearing, shorter time enabling off bed ambulation, lesser postoperative pain, lesser complication rate, lesser loosening rate, lesser malunion rate, and lesser postoperative osteoarthritis.

CONCLUSIONS

Plate fixation is a favorable alternative to screw fixation in posterior malleolar fractured patients. Although plate fixation was at risk of longer surgery time and more blood loss, it provided better postoperative functional outcome, shorter healing, weight bearing and off bed ambulation time and lesser pain compared to screw fixation.

Fixation of Posterior Malleolus in Trimalleolar Ankle Fractures: Anteroposterior Screw or Posterolateral Plate?

Background: The treatment of the third malleolus has evolved in recent years, and surgical treatment can be carried out with traditional percutaneous osteosynthesis using anteroposterior screws or ORIF with a posterolateral plate. Methods: Our study included 54 patients divided into two groups based on the intervention type (screw or plate). Instrumental assessments comprised pre- and post-operative X-rays and pre-operative CT scans to evaluate joint step-off. The mean follow-up duration was 1 year and 9 months. Results: Radiographic control revealed no loss of reduction or mobilization of the synthesis devices, and all patients achieved fracture healing. Articular step-off > 2 mm was observed in 21 patients (38.9%), including 4 in the plate group and 17 in the screw group, with a statistically significant likelihood of step-off presence in the latter. The mean AOFAS score was 90 points, negatively correlated with age, and lower in patients with joint step-off and a 15° reduction in ROM. Conclusions: The management of posterior malleolus fractures has changed with anatomical studies and an understanding of ankle stability through CT scans. ORIF with a posterior plate is advantageous for anatomical reduction of the tibial plafond but is disadvantageous in terms of surgical invasiveness and technical difficulty.

[Comparison of posterolateral approach and combined approach in treatment of Mason type 2B posterior malleolar fracture]

Objective

To compare the effectiveness between the posterolateral approach and the posterolateral combined posteromedial approaches in the treatment of Mason type 2B posterior malleolar fracture.

Methods

A retrospective analysis was performed on the clinical data of 79 patients with posterior ankle fracture who met the selection criteria between January 2015 and January 2022. There were 62 cases of Mason 2B Pilon subtype and 17 cases of avulsion subtype. Among Mason 2B Pilon subtype patients, 35 were treated with posterolateral approach (group A), 27 patients were treated with combined approach (group B). There was no significant difference in gender, age, injured side, cause of injury, time from injury to operation, preoperative hospital stay, preoperative visualanalogue scale (VAS) score, and intraoperative internal fixation between the two groups ( P>0.05). All patients with Mason 2B avulsion subtype were treated by posterolateral approach, including 7 males and 10 females, aged from 25 to 68 years, with an average of 46.1 years. The operation time, intraoperative blood loss, postoperative hospital stay, and complications were recorded. The reduction quality was evaluated by Ovadia deals radiographic score, and the ankle function and pain were evaluated by VAS score, American Orthopaedic Foot and Ankle Society (AOFAS) score, and ankle range of motion.

Results

Mason 2B Pilon subtype: There was no significant difference in operation time, intraoperative blood loss, postoperative hospital stay, and follow-up time between the two groups ( P>0.05). The radiological evaluation of Ovadia deals in group A was significantly worse than that in group B ( P<0.05). The VAS score in the two groups significantly improved at each time point after operation, and the VAS score and AOFAS score further improved with the extension of time after operation, and the differences were significant ( P<0.05). Except that the AOFAS score of group A was significantly lower than that of group B at last follow-up ( P<0.05), there was no significant difference in VAS score and AOFAS score between the two groups at other time points ( P>0.05). At last follow-up, the ankle range of motion in group A was significantly less than that in group B ( P<0.05). There was no significant difference in the incidence of sural nerve injury, deep tissue infection, limitation of toe movement, and traumatic ankle arthritis between the two groups ( P>0.05). Mason 2B avulsion subtype: The operation time was (119.47±20.61) minutes and the intraoperative blood loss was 50 (35, 55) mL. Seventeen patients were followed up 13-25 months, with an average of 18 months. The Ovadia deals score was excellent in 10 cases, good in 6 cases, and poor in 1 case at 1 week after operation, and the excellent and good rate was 94.1%. All fractures healed in 8-18 weeks with an average of 12.35 weeks. There were 1 case of sural nerve injury and 3 cases of traumatic ankle arthritis after operation. No deep tissue infection or limitation of toe movement occurred. The VAS score decreased significantly and AOFAS score increased significantly with time, and the differences were significant between different time points before and after operation ( P<0.05). The ankle range of motion at last follow-up was (56.71±2.47)°.

Conclusion

Compared with the posterolateral approach, the combined approach is a better choice for the treatment of Mason 2B Pilon subtype. If the posteromedial bone block does not affect the reduction of the medial malleolus, the posterolateral approach can achieve good effectiveness for Mason 2B avulsion subtype.

Treatment strategies for complex ankle fractures-current developments summarized in a narrative review

Background and Objective

Ankle fractures occur frequently in patients throughout all ages. Due to the many pitfalls associated with their treatment, complex ankle and especially tibial pilon fractures remain a challenge for surgeons. As there is still need for improvement in treating complex ankle fractures and treatment options are steadily increasing this review aims to summarize current practice and aims to highlight current developments by reviewing the literature.

Methods

We conducted a thorough search of PubMed database in December 2022 to identify relevant articles on complex ankle and tibial pilon fractures. Articles in English and German were included in this study.

Key Contents and Findings

Complication rates, especially wound infection are still high, emphasizing the need for careful preoperative planning. Soft tissue management is crucial to reduce complication rates and will often dictate the treatment plan utilized. Open reduction and internal fixation (ORIF) remains the treatment of choice. Nevertheless, in select cases alternative methods such as external fixation, tibiotalocalcaneal nailing or conservative treatment need to be considered as well. Furthermore, additional treatment options such as arthroscopically assisted surgery might help to improve functional outcome after complex ankle fractures. The incidence of complex ankle fractures in geriatric patients keeps rising with our aging population. This group of patients demands particular care and further high-quality studies are needed to warrant best results.

Conclusions

However, more randomized controlled trials are need in order to enhance evidence of newly developed treatment options.

Current concepts in ankle fractures

Ankle fractures are among the most common orthopaedic injuries. Operative management is performed in unstable ankle fracture patterns to restore the stability and native kinematics of the ankle mortise and minimize the risk of post-traumatic degenerative changes. In this study, we review current concepts in ankle fracture management, including posterior malleolus fixation, syndesmosis fixation, deltoid ligament repair, fibular nailing, and early weightbearing, from both a biomechanical and clinical perspective.

Direct fixation of posterior malleolus fractures-posterolateral or posteromedial approach?

Ankle fractures involving the posterior malleolus (PM) generally have worse prognosis. There is a trend towards it's direct fixation, yet the exact indications are a subject of debate. The purpose of our study was to present our treatment protocol and to discuss the advantages and limitations of the direct posterolateral and posteromedial approaches. We present a prospective series of 35 ankle fractures involving the PM, operated for a period of 4 years (2018-2022). Direct posterolateral approach was used in 20 ankles, 15 were operated via a posteromedial approach. Clinical and functional assessment was performed according to the criteria of AOFAS. 14 patients received an excellent score, 16 had good and the rest had an average score. The overall score was 85,4 (54-100). The average range of motion was 50° (15°-55°).Eight patients had superficial skin necrosis along the surgical incision. Thirteen patients need their fibular plates removed due to local irritation. Five patients, operated through a posterolateral approach, had lateral heel numbness suggestive of a sural nerve disfunction. PM is important for normal ankle kinematics. When it's direct fixation is considered appropriate, the safest and shortest route is optimal. It is determined by the preoperative CT. The posterolateral approach is more versatile, but lead to more complications in our study.

Open Reduction and Internal Fixation of the Posterior Malleolus Fragment in Ankle Fractures Improves the Patient-Rated Outcome: A Systematic Review

BACKGROUND

The best treatment strategy for fractures to the posterior malleolus (PM) is still intensively debated. The aim of this systematic review was to compare the patient-rated outcome following open reduction and internal fixation (ORIF) for fractures of the PM to either closed reduction using AP screws (CRIF) or no treatment in bi- or trimalleolar ankle fractures.

METHODS

Systematic literature research (MEDLINE (PubMed), CINAHL, Scopus, Central and EMBASE) according to the PICOS and PRISMA guidelines. Eligible were studies comparing the outcome following ORIF to any other treatment strategy for fractures to the posterior malleolus in isolated bi- or trimalleolar ankle fractures.

RESULTS

Twelve studies were eligible for a qualitative analysis and 6 for a quantitative analysis. Overall, a considerable heterogeneity among the studies was observed. The most commonly used outcome score was the American Orthopaedic Foot & Ankle Society ankle-hindfoot score (AOFAS). The final follow-up ranged from 12 to 160 months. Four studies compared ORIF to CRIF of the PM. The quantitative analysis revealed significantly better AOFAS scores for ORIF (90.9 vs 83.4 points; P < .001; I2 = 0%). Three studies compared ORIF to untreated PM fragment. The quantitative analysis again revealed superior AOFAS scores for ORIF (92.0 vs 82.5 points; P < .001; I2 = 99%). A similar trend was observed for the Ankle Fracture Scoring System and American Academy of Orthopaedic Surgeons Foot and Ankle Questionnaire scores as well as the quality of reduction.

CONCLUSION

Despite a considerable heterogeneity, the data available point to a superior outcome following ORIF for fractures to the PM when compared to CRIF or no treatment.

Classifications of posterior malleolar fractures: a systematic literature review

INTRODUCTION

Complex ankle fractures frequently involve the posterior malleolus. Many classifications describing posterior malleolar fractures (PMF) exist. The aim of this study was to provide a systematic literature review to outline existing PMF classifications and estimate their accuracy.

METHODS

The databases PubMed and Scopus were searched without time limits. Only specific PMF classifications were included; general ankle and/or pilon fracture classifications were excluded. Selection and data extraction was performed by three independent observers. The systematic literature search was performed according to the current criteria of Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). The methodological quality of the included studies was quantified using the modified Coleman score.

RESULTS

A total of 110 studies with a total of 12.614 patients were included. Four main classifications were identified: Those describing the size of the posterior malleolar fracture (n = 66), Haraguchi (n = 44), Bartoníček/Rammelt (n = 21) and Mason (n = 12). The quality of the studies was moderate to good with a median Coleman-score of 43.5 (14-79) and a weighted median Coleman-score of 42.5 points. All classifications achieved a substantial to perfect score regarding the inter- and intraobserver reliability, with Mason scoring the lowest in comparison.

CONCLUSIONS

None of the reviewed PMF classifications has been able to establish itself decisively in the literature. Most of the classifications are insufficient in terms of a derivable treatment algorithm or a prognosis with regard to outcome. However, as the Bartoníček/Rammelt classification has the greatest potential due to its treatment algorithm, its reliability in combination with consistent predictive values, its usage in clinical practice and research appears advisable.

Reduction of Posterior Malleolus Fractures With Open Fixation Compared to Percutaneous Treatment

Background

Operative decision making between approaches to posterior malleolus reduction remains a challenge. The purpose of this study is to compare the quality of reduction between percutaneous and open reduction of posterior malleolus fractures and to identify factors associated with malreduction.

Methods

Operatively managed ankle fractures that included posterior malleolus fixation were reviewed. Fracture characteristics were determined on preoperative CT scans. Initial postoperative radiographs were used to measure reduction of the posterior malleolus articular surface and graded as satisfactory (<2 mm step-off) or malreduced (≥2 mm step-off). Final postoperative PROMIS scores and 1-year complications were compared between percutaneous and open cohorts. A multivariate stepwise regression model was used to evaluate predictors for malreduction.

Results

A total of 120 patients were included. Open reduction was performed in 91 (75.8%) compared with 29 (24.2%) who underwent percutaneous reduction. Malreduction (≥2-mm articular step-off) occurred in 11.7% of patients. Malreduction rates were significantly higher with percutaneous fixation than open fixation (24.1% vs 7.7%, P = .02). Multiple fragments and those with ≥5 mm of displacement demonstrated higher malreduction rates with percutaneous fixation (P < .05 for both), whereas single fragments and those with <5 mm of displacement experienced similar malreduction rates with percutaneous or open fixation. Initial displacement ≥5 mm (relative risk [RR] = 3.8, 95% CI = 1.2-11.5, P = .02) and percutaneous treatment (RR = 4.1, 95% CI = 1.6-10.5, P < .01) were identified as independent risk factors for malreduction. There were no significant differences in 1-year complication rates or final PROMIS scores between groups.

Conclusion

Open reduction of the posterior malleolus may lead to improved fracture reduction compared to percutaneous reduction without significant increase in complications. Open fixation improves reduction among fractures with multiple fragments or ≥5 mm of displacement, whereas fractures with a single fragment or <5 mm of displacement achieve similar reductions regardless of approach. Initial displacement ≥5 mm and percutaneous reduction are independent risk factors for malreduction.

Level of evidence

Level III, therapeutic.

Morphological study of CT image of posterior pilon variant fracture and its possible clinical significance

OBJECTIVE

The incidence of posterior pilon variant fractures has been underestimated. The purpose was to study the characteristics of posteromedial (PM) and posterolateral (PL) fragments in CT imaging of posterior pilon variant fractures, and to provide help for clinical diagnosis and treatment.

METHODS

CT imaging data of 109 cases of posterior pilon variant fractures in our hospital from January 2013 to December 2020 were retrospectively analyzed. According to Mason and Molloy classification, PM fragments were further divided into pilon subtypes and avulsed subtypes. The largest actual area of fragments in axial and sagittal were selected as the study plane, and the maximum axial lengths of X, Y and Z, α angle, β angle, fragment area (S1-7) and fragment area ratio (FAR1-4), interfragmentary (IF) angle, and back of tibia (BT) angle were measured.

RESULTS

A total of 109 cases were included in this study, 61 of whom were pilon subtypes [90.16% were supination-external rotation (SER) injuries]. 48 cases were avulsed subtypes [81.25% were pronation-external rotation (PER) injuries]. Pilon subtypes were larger than avulsed subtypes in X, Y, Z, α₂ Angle, β₂ Angle, fragment area and ratio, and IF and BT angle (P < 0.05). There was no difference between α₁ and β₁ angle (P > 0.05).

CONCLUSION

The morphology of pilon subtype was larger than that of avulsion subtype. According to fragment size, morphology, and injury mechanism, two fragments of pilon subtype should be anatomic reduction and fixation. However, the PL fragment of avulsion subtype should to be fixed, while PM fragment may only need conservative treatment.

Open reduction and internal fixation for posterior pilon fracture: Transfibular approach versus posterior approach

BACKGROUND

For posterior pilon fractures, the posterior approach (PA) is widely used but has its limitations. The transfibular approach (TFA) has been adopted to treat posterior malleolar fractures for the advantage of direct visual confirmation of the reduction status intraoperatively, yet the report of its application on posterior pilon fractures is rare. This study aims to compare TFA with PA in terms of their corresponding reduction quality.

METHODS

Clinical data of 85 posterior pilon fracture patients treated via PA (n = 62) or TFA (n = 23) were retrospectively reviewed. Radiographic and clinical assessments, including articular step-off or gap, syndesmosis reduction quality, signs of ankle arthritis, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS), ankle stability, and the active range of motion (ROM) of the ankle, were all evaluated by two readers independently.

RESULTS

The total incidence of step-off or gap ≥ 1 mm was significantly higher in the PA group (35.5%) than in the TFA group (8.7%, p = 0.015). In all the patients, step-off ≥ 1 mm was identified as an independent risk factor for the development of arthritis and a lower AOFAS score (p < 0.001). No significant difference was found in ROM and complication incidence between the two groups. Ankle instability was found in neither group during the follow-up.

CONCLUSION

TFA could offer a way to intraoperatively evaluate the reduction status with direct visual confirmation and, thereby, might improve the results of reduction for posterior pilon fractures.

LEVEL OF EVIDENCE

Level III.

Single lateral approach for open reduction and internal fixation of posterior malleolar fragment in Weber B rotational ankle fracture

Ankle fractures involving the posterior malleolus are a relatively common injuries, but various surgical approaches are still being introduced, and the selection of an appropriate surgical method is still controversial. The aim of this study was to introduce the surgical method using a single lateral approach for open reduction and internal fixation for posterior malleolar (PM) fractures associated with Weber B type ankle fractures. In this retrospective study, the single lateral approach was used for osteosynthesis of the PM fracture with Weber B lateral malleolar fractures. A total of 40 patients were followed up at for least 12 months (mean, 23.3; range, 12-88). Clinical assessment was based on the Olerud and Molander score, Foot and Ankle Outcome Score, visual analog scale, and subjective patient satisfaction 1 year after surgery. The accuracy of reduction was evaluated as <1 mm of displacement on the lateral view of the postoperative radiographs. The mean Olerud and Molander ankle score was 85.6 ± 12.7 and the mean Foot and Ankle Outcome Score was 82.7 ± 15.9 at 1-year postoperatively. Acceptable reduction was achieved in 38 of 40 (95%) cases. During the follow-up period, arthritic change was observed in 1 case and limited range of motion was confirmed in 2 cases. There was 1 case of postoperative wound problem and no case of sural nerve injury. The single lateral approach is a relatively simple and convenient method that enables accurate reduction and minimizing complication for fixation of the PM fractures with Weber B lateral malleolar fractures.

Fracture gap of the lateral malleolus via posterolateral approach: Improved visualization of the posterior malleolus fracture

The treatment of posterior malleolar fractures is a popular issue. Anatomic reduction of posterior malleolar fractures is critical for re-establishing the stability of the ankle mortise and ligamentous union after trauma. Inappropriate treatment ultimately leads to poorer functional outcomes and lower quality of life. Open reduction and internal fixation through a posterolateral approach are preferred over indirect reduction and anterior-posterior screw fixation. Although the posterolateral approach, which is more common and direct, provides good exposure to the fracture site, it has some limitations. In this report, we describe the posterolateral approach through the lateral ankle fracture gap for the treatment of posterior ankle fractures. Moreover, we discuss the indications, benefits, and limitations of this approach.

Open reduction and internal fixation of the posterior malleolus fragment via the posterolateral approach is radiologically superior to 'A to P' screw fixation

PURPOSE

Functional outcome in trimalleolar fractures is largely correlated to the reduction of the posterior fragment. Until recently, fixation was mainly performed for large fragments, by percutaneous anterior to posterior ('A to P') screw placement after closed reduction. Nowadays, ORIF via a posterolateral approach seems to gain in popularity. The aim of this study was to compare the postoperative photographs of operated trimalleolar fractures after either fracture treatment method, for fracture diastasis and step-off.

MATERIAL AND METHODS

All consecutive patients with trimalleolar fractures, including posterior fragments of >5% of the articular surface and operated between 2007-2013 were analysed on size of posterior fragment, post-operative gap and step-off by three observers. The patients were divided into three groups; A to P screw fixation, ORIF via the posterolateral approach and no posterior fragment fixation at all.

RESULTS

180 patients with trimalleolar ankle fractures were included for analyses. Twenty five posterior fragments were fixated percutaneously from anterior to posterior (group 1) and 51 underwent open reduction and internal fixation through a posterolateral approach (group 2). 104 patients underwent no posterior malleolus fixation (group 3). The average size of posterior fragment was 34% in group 1, 27% in group 2 and 16% in group 3. A postoperative step-off >1 mm was found in 40% (group 1), 9% (group 2) or 34% respectively (group 3).

CONCLUSIONS

Fixation of the posterior malleolus through an open posterolateral approach leads to better radiological results as compared to percutaneous 'A to P' screw fixation or no fixation at all.

Direct Fixation of Fractures of the Posterior Malleolus Through a Postero-Medial Approach

Background and objective: Fractures of the posterior malleolus have long been neglected in the past. The decision for their fixation should be based on plain lateral radiographs. Recent studies have emphasized the important biomechanical function of the posterior tibial ridge. This has caused a trend towards more aggressive surgical treatment. The aim of this study was to present our experience with the direct fixation of complex ankle fractures engaging the posterior malleolus. We also tried to clarify the advantages and limitations of the posterior-medial surgical approach.

Materials and Methods: For a period of 1,5 years we have operated 14 patients with posterior malleolus fractures. Their average age was 51 years. Eight of the patients were male, the rest 6 were females. Fractures were classified according to Bartoníček classification system. All patients had type 3 fractures. Direct open reduction was performed in all cases. Posterior buttress plate was used for the fixation of the fracture. Bone grafting was found necessary in one case. Functional assessment was done according to the criteria of the AOFAS (American Orthopedic Foot and ankle score). Follow up was done for an average period of 10 months.

Results: All fractures united for an average period of 9 weeks (8-10 weeks). Six patients achieved an excellent functional result, 5 – a good one and 3 had an average result. The average AOFAS rating score was 84,02 (54-100). The average range of motion was 38° (15°-50°). There were no deep infections or septic arthritis. Three ankles had superficial skin necrosis that healed without any additional procedures. One patient had prolonged and substantial swelling of the leg, despite of the routine antithrombotic prophylaxis. Five patients needed their fibular plates removed due to local irritation.

Conclusion: The direct reduction and fixation of the posterior malleolus fractures allow anatomical restoration of the ankle mortise. This is a prerequisite for an optimal functional recovery and appears to be a safe treatment strategy.

Ankle fractures involving the posterior malleolus: patient characteristics and 7-year results in 100 cases

INTRODUCTION

The presence of a posterior malleolar (PM) fragment has a negative prognostic impact in ankle fractures. The best treatment is still subject to debate. The aim of this study was to assess the medium-to-long-term clinical and functional outcome of ankle fractures with a PM fragment in a larger patient population.

MATERIALS AND METHODS

One hundred patients (69 women, 31 men, average age 60 years) with ankle fractures including the PM were evaluated clinically and radiographically. Patients with Bartoníček-Rammelt type 3 and 4 fracture displayed a significant female preponderance. Fixation of the PM was performed in 63% and tailored to the individual fracture pattern.

RESULTS

Internal fixation of the PM fragment was negatively correlated with the need for syndesmotic screw placement at the time of surgery (p = 0.010). At an average follow-up of 7.0 years, the mean Foot Function Index (FFI) was 16.5 (SD: 21.5), the Olerud Molander Ankle Score (OMAS) averaged 80.2 (SD: 24) and the American Orthopedic Foot & Ankle Society (AOFAS) ankle/hindfoot score averaged 87.5 (SD: 19.1). The maximum score of 100 was achieved by 44% of patients. The physical (PCS) and mental health component summary (MCS) scores of the SF-36 averaged 47.7 (SD: 12.51) and 50.5 (SD: 9.36), respectively. Range of motion was within 3.4 (SD: 6.63) degrees of the uninjured side. The size of the PM fragment had no prognostic value. There was a trend to lower outcome scores with slight anterior or posterior shift of the distal fibula within the tibial incisura. Patients who underwent primary internal fixation had significantly superior SF-36 MCS than patients who underwent staged internal fixation (p = 0.031).

CONCLUSIONS

With an individualized treatment protocol, tailored to the CT-based assessment of PM fractures, favorable medium and long-term results can be expected.

Distribution of posterior malleolus fracture lines in ankle fracture of supination-external rotation

INTRODUCTION

Supination-external rotation ankle fracture is one of the most common fractures. Studies on the fracture line distribution of this fracture type are limited. The purpose of this study is to explore the distribution characteristics of intra-articular posterior malleolus fracture lines in supination-external rotation.

HYPOTHESIS

Most of the fracture lines are concentrated in a particular area.

MATERIAL AND METHODS

Computed tomography scans of a consecutive series of 70 ankle fractures of supination-external rotation were used for this study. The DICOM files were loaded into Mimics 16.0 for 3D reconstruction of the distal tibial articular surface. The intra-articular posterior malleolus fracture lines were identified after virtual fracture reduction. All the fracture lines were drawn on one picture of the distal tibial articular surface after standardization before a heat map was created based on the frequency of fracture lines.

RESULTS

Although the distribution of posterior malleolus intra-articular fracture lines varied, most of them were concentrated in an arcuate zone. The ratios of the area of posterior fracture fragment to the total area of articular surface averaged 14.96% (range, from 2.23% to 38.45%). They were most likely to enter the articular surface at 20.4% of the tangent of the posterior edge in a standardized image and exit at 58.7% of the tangent of the lateral edge.

CONCLUSIONS

In ankle fractures of supination-external rotation, most intra-articular posterior malleolus fracture lines may be distributed regularly in an arcuate zone of the articular surface.

LEVEL OF PROOF

V; Descriptive research.

Current management of trimalleolar ankle fractures

A trimalleolar ankle fracture is considered unstable and treatment is generally performed operatively. Computed tomography is important for the operative planning by providing an elaborated view of the posterior malleolus.

Trimalleolar ankle fractures have a rising incidence in the last decade with up to 40 per 100,000 people per year. With a growing number of elderly patients, trimalleolar ankle injuries will become more relevant in the form of fragility fractures, posing a particular challenge for trauma surgeons.

In patients with osteoporotic trimalleolar ankle fractures and relevant concomitant conditions, further evidence is awaited to specify indications for open reduction and internal fixation or primary transfixation of the ankle joint.

In younger, more demanding patients, arthroscopic-assisted surgery might improve the outcome, but future research is required to identify patients who will benefit from assisted surgical care.

This review considers current scientific findings regarding all three malleoli to understand the complexity of trimalleolar ankle injuries and provide the reader with an overview of treatment strategies and research, as well as future perspectives.

Cite this article: EFORT Open Rev 2021;6:692-703. DOI: 10.1302/2058-5241.6.200138

The Association Between Lateral Radiographs and Axial Computed Tomography of Posterior Malleolar Fractures as a Tool for Predicting Medial Malleolar Extension: A Multi-Center Retrospective Analysis

Posterior malleolar fractures are often part of complex ankle fracture patterns. Radiographs and computed tomography are often obtained in the preoperative setting. In this study, we compared measurements from lateral ankle radiographs with measurements on axial computed tomography. We hypothesize that there is an association between measurements taken on lateral XR and certain fracture morphology such as medial extension and that measurements taken on lateral XR can be used to predict likelihood of medial extension type fractures. A multi-center retrospective analysis was performed involving patients with trimalleolar ankle fractures treated at two large urban healthcare systems ranging from January 1, 2010 to November 1, 2019. A total of 279 patients met criteria including 186 females and 93 males aged 18 to 90 with an average age 55. Four reviewers measured continuous variables on lateral radiograph and axial computed tomography: posterior malleolus fracture height, articular surface length, medial-lateral width, and anterior-posterior depth and then agreement was assessed via intraclass correlation coefficient. Pearson correlations were calculated for all pairwise combinations of measurements. Two fracture classification systems were then evaluated for association with the continuous variables. Lateral height was divided into quartiles and analyzed for the degree of association. Positive correlation was found between lateral height and axial depth/axial width. Taller lateral height values were statistically associated with medial extension type fractures. Lateral height 24.5mm-29.5mm is 3.1x higher, and lateral height >29.5mm is 8.6x more likely to have medial extension when compared to shorter lateral heights(<20.5mm). Based on these findings we suggest increased usage of pre-operative CT and evaluation for the use of posteromedial approaches in the setting of taller lateral height fracture patterns(>24.5mm) as seen on lateral XR.

Defining a Safe Zone for Percutaneous Screw Fixation of Posterior Malleolar Fractures

Posterior malleolar fractures require fixation to confer stability to the ankle. Although some have suggested that fractures involving less than 25% of the articular surface require no intervention, estimation of malleolar size on plain imaging is inaccurate. Some posterior malleolar fractures may be particularly suitable for posterior-to-anterior percutaneous screw fixation of the posterior malleolus via a posterolateral approach. We hypothesized that there may be a safe zone in the posterolateral ankle, identifiable with reliable anatomic landmarks, that might allow safe percutaneous screw placement for fracture fixation. The study protocol involved Step 1, in which multiple Kirschner wires were used in a single cadaveric specimen to attempt to identify a safe zone entry point in the posterior ankle, and Step 2, in which a single wire was used in each of six additional cadaveric specimens to test the ability to safely replicate the use of that entry point. In Step 1, a safe zone entry point was identified, located immediately lateral to the Achilles tendon and 1 cm above the level of the tip of the medial malleolus, when visualizing the posterior ankle. In Step 2, using these landmarks and an image intensifier, single wires were then successfully placed in the other six specimens without injury to any significant structure. If confirmed in clinical studies, the safe zone entry point that we have identified could potentially be used to facilitate posterior-to-anterior percutaneous fixation in patients with posterior malleolar fractures for whom open reduction may not be required or may be contraindicated.

Posterior Malleolar Fractures: A Critical Analysis Review

In patients with ankle fractures, the presence of a posterior malleolar fracture has a negative impact on the prognosis. Computed tomography (CT) scanning is essential for fracture classification and treatment planning, as the indication for surgery depends on the 3-dimensional fragment outline and displacement, incisura involvement, and the presence of joint impaction. Anatomic reduction of a posterior malleolar fragment restores the incisura, facilitating reduction of the distal part of the fibula, and it also restores the integrity of the posterior portion of the syndesmosis, reducing the need for additional syndesmotic stabilization. Direct open reduction and fixation of posterior malleolar fragments from a posterior orientation is biomechanically more stable and provides a more accurate reduction than does indirect reduction and anterior-to-posterior screw fixation. Intra-articular step-off of >=2 mm is an independent risk factor for an inferior outcome and the development of posttraumatic arthritis, irrespective of the fragment size.

Posteroanterior Lag Screws Versus Posterior Buttress Plate Fixation of Posterior Malleolar Fragments in Spiral Tibial Shaft Fracture

The aim of this study is to compare the clinical outcomes of posteroanterior (PA) lag screws versus posterior buttress plate fixation in treatment of posterior malleolar fragments (PMFs) in spiral tibial shaft fracture, and provide guidance for surgeons selecting a treatment strategy. A total of 48 eligible patients with PMFs associated with spiral tibial shaft fracture surgically treated from March 2009 to January 2016 were included in the study. They were divided into the screw group (n = 24) and the plate group (n = 24). All operations were performed via a posterolateral approach by a senior orthopedic surgeon. The American Orthopaedic Foot and Ankle Society (AOFAS) score, visual analog scale (VAS), and assessment of ankle range of motion (ROM) were used for clinical evaluation. The radiographic evaluation of posttraumatic arthritis scale was determined by Bargon reference criteria. At the mean follow-up period of 29.5 ± 4.3 and 30.4 ± 4.1 months, respectively (p > .05), all patients in both groups had bone union without severe wound problems or complications. There were no significant differences in AOFAS (92.5 ± 5.3 vs 94.7 ± 5.6, p = .129) and VAS (2.4 ± 0.8 vs 2.2 ± 0.9, p = .196) scores between the groups at final follow-up. No significant differences were found between the groups in injured/contralateral ankle ROM or posttraumatic ankle arthritis scale postoperatively (p > .05). For PMFs in spiral tibial shaft fracture, PA lag screws or posterior buttress plate fixation via a posterolateral approach can achieve good and equivalent clinical and radiological outcomes with minimal complications.

The CT morphological characteristics and the clinical management strategy of posterior malleolar fractures with talar subluxation

BACKGROUND

The optimal clinical treatment and the computed tomography (CT) morphological characteristics of posterior malleolar fractures (PMF) with talar subluxation remain inconclusive. Clinically, both plate screws and lag screws are widely used to fix posterior malleolar fragments using a direct or indirect approach. We sought to summarize the morphological characteristics and modified classification on the basis of CT and the intraoperative strategy for posterior talar subluxation in PMF.

METHODS

Retrospectively, 46 adult PMF patients with subluxations of the talus were recruited as the study cohort. According to its morphological features, PMF with subluxation of the talus can be divided mainly into two types using this modified classification: a complete fracture (the single-fragment type) and PMF with two-angled fracture fragments (the double-fragment type). The cohort's demographic information, classifications, fracture morphology, fixation methods, pain levels, and functional scores were recorded for both fracture types.

RESULTS

The average values of the depths and heights of the posterior malleolar fragments were (29.1±7.3) mm for the single-fragment type and (17.9±4.2) mm for the double-fragment type. There was a significant difference in the mean values between the two types (P < 0.05). Posterior plate fixation was suitable for the single-fragment type, while antero-posterior and postero-anterior (AP-PA) lag screws fixations were made available for the double-fragment type. Both methods achieved good results. No significant differences were found in terms of sex, age, body mass index (BMI), side, Haraguchi classification, Bartoníček and Rammelt classification, Visual Analog Scale (VAS) scores, or American Orthopedic Foot & Ankle Society scores (AOFAS) when comparing the single-/double-fragment type groups after the mid-term follow-up (P > 0.05).

CONCLUSION

According to the injury mechanism and the morphological characteristics of the fractures, the proposed improved classification system for PMF with subluxation of the talus based on the injury mechanism and the fracture morphology can provide guidance for surgical management strategies and achieve optimal outcomes.

Surgical Fixation of Quadrimalleolar Fractures of the Ankle

We present a technique of fixation of trimalleolar fractures with additional fracture of the anterior tibial tubercle ("quadrimalleolar") or anterior fibular rim ("quadrimalleolar equivalent"). Twenty-four patients with a mean age of 60 years were treated with open reduction and internal fixation of all 4 malleoli. There were 17 quadrimalleolar and 6 quadrimalleolar equivalent fractures. One patient had both anterior tibial and fibular avulsion fracture in addition to a trimalleolar ankle fracture. Surgical approaches and internal fixation were tailored individually. Twenty patients were operated in the prone position with direct fixation of the posterior malleolus and 4 patients in the supine position with anterior to posterior screw fixation of the posterior malleolus. After fixation of al 4 malleoli, only 1 patient (4%) required a syndesmotic screw for residual syndesmotic instability on intraoperative testing. There were no infections and no wound healing problems. All patients went on to solid union. Nineteen patients (79%) were followed for a mean of 77 months (range, 15-156 months). The Foot Function Index averaged 15 (range, 50 to 0), the Olerud and Molander Score averaged 79 (range, 45-100), and the American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Scale averaged 87 (range, 39-100). Fixation of the anterior and posterior tibial fragments increases syndesmotic stability by providing a bone-to-bone fixation. Anatomic reduction of the anterior and posterior tibial rim restores the physiological shape of the tibial incisura and therefore facilitates fibular reduction.

Traditional Approach vs Posterior Approach for Ankle Fractures Involving the Posterior Malleolus

BACKGROUND

In the past, posterior malleolus fragments (PMFs) commonly have been indirectly reduced and fixed when fragments involve 25% or more of the tibial articular surface, while smaller fragments were left unfixed. The posterior approach has become increasingly popular and allows fixation of even smaller fragments. This study compares clinical outcome for the 2 treatment strategies.

METHODS

Patients with ankle fractures involving a PMF treated from 2014 to 2016 were eligible for inclusion. Patients were allocated to group A (treated with a posterior approach) or group B (treated with the traditional approach) according to the treatment given. A one-to-one matching of patients from each group based on the size of the PMF was performed. Patient charts were reviewed, and outcome evaluation was performed clinically, radiographically, and by patient-reported outcome measures (PROMs; Self-Reported Foot and Ankle Score, RAND-36, visual analog scale [VAS] of pain, and VAS of satisfaction). Forty-three patients from each group were matched. Median follow-up was 26 (interquartile range [IQR], 19-35) months postoperatively.

RESULTS

The median PMF size was 17% (IQR, 12-24) in both groups, and they reported similar results in terms of PROMs. Fixation of the PMF was performed in 42 of 43 (98%) patients in group A and 7 of 43 (16%) patients in group B (P < .001). The former group more frequently got temporary external fixation (56% vs 12%, P < .01) and less frequently had syndesmotic fixation (14% vs 49%, P < .01), and they had less mechanical irritation and hardware removal but more noninfectious skin problems (28% vs 5%, P < .01). Median time from injury to definitive surgery (8 vs 0 days, P < .001) and median length of stay (12 vs 3 days, P < .001) were longer in group A.

CONCLUSION

Comparison of treatment strategies for ankle fractures involving the posterior malleolus showed similar results between patients treated with a traditional approach and a posterior approach.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Trimalleolar fracture: The endless posterior malleolus fracture debate, to repair or not to repair?

Ankle fracture is one of the most common fractures presenting in the emergency department. The fracture varies from unimalleolar, bimalleolar or trimalleolar. Involvement of the posterior malleolus is common and ranges from small avulsions to large intraarticular fragments causing subluxation of the talus. If left untreated, the resulting step-off, comminution or posterior talar subluxation may lead to osteoarthritis and further disability. To date, no consensus exists regarding the management of posterior malleolus fractures in the set-up of trimalleolar fractures. In this review we provide an overview of the literature on the available treatment options for posterior malleolar fracture in the set-up of trimalleolar fractures.

[Open reduction and internal fixation of posterior malleolus fractures]

OBJECTIVE

Stabilization of the syndesmotic complex by open reduction and internal fixation (ORIF) of the posterior malleolus, restoration of the tibial articular surface, stability of the ankle, posterior tibiofibular ligament and the incisura tibiae, reduction of the fibula into the incisura tibiae by ligamentotaxis.

INDICATIONS

Unstable ankle fractures (OTA/AO type 44-B3, C1.3, C2.3, C3.3) with involvement of the posterior malleolus (type II-IV according to Bartoníček and Rammelt).

CONTRAINDICATIONS

Critical general condition, circulatory disorders, severe soft tissue swelling (if necessary, first external fixator), percutaneous treatment the better alternative.

SURGICAL TECHNIQUE

Positioning in unstable lateral position, dorsolateral approach dorsally of the peroneal tendons, incision of the superficial and deep fascia, retraction of the flexor hallucis longus tendon medially, visualization of the posterior malleolus, reduction and fixation. To treat the lateral malleolus fracture, preparation of a full-thickness flap above the peroneal tendons on the fibula, treatment according to AO principles. For the treatment of the medial malleolus positioning in supine position without changing the sterile covers, medial approach for the medial malleolus, wound closure.

POSTOPERATIVE MANAGEMENT

Six weeks partial weight bearing (20 kg), early functional exercise, exercise of the flexor hallucis longus muscle; transition to full weight bearing after clinical and radiological follow-up after 6 weeks RESULTS: Few clinical results on open ORIF of the posterior malleolus have been published. However, most studies found that ORIF resulted in better reconstruction of the distal articular surface and the tibial incisura, better reduction of the fibula into the tibial incisura, stabilization of the distal tibiofibular joint and better clinical results, regardless of fragment size, when compared to closed reduction or untreated fragments.

Clinical outcomes and trans-syndesmotic screw frequency after posterior malleolar fracture osteosynthesis

AIM

This study aimed to evaluate the clinical outcomes and the trans-syndesmotic screw frequency after trimalleolar ankle fractures with a posterior malleolus fracture involving <25% of the articular surface.

MATERIAL AND METHODS

Retrospective comparative study. Patients with trimalleolar ankle fracture who underwent surgery between January 2011 and January 2018 were identified within the departments' fracture database. General demographics, treatment details, and fracture specific details (CT-scans) were assessed. Patients were grouped per the posterior malleolus fragment treatment: osteosynthesis (group 1) and non-osteosynthesis (group 2).

RESULTS

64 patients, 58.6 ± 17.8 years (range: 23-75), 68.8% female were eligible and follow up time was 43.1 ± 22.2 (range 24-96) months. The mean size of the posterior malleolus fragment was 14.7 ± 5.3% (range: 5-24). Posterior malleolus fragment treatment distribution: osteosynthesis (group 1) 31.2% and non- osteosynthesis (group 2) 68.8%. Group 1 showed significantly better clinical outcomes (p<0.05), AOOS (93.9 ± 5.79 (range: 73-99), AOFAS (91.5 ± 6.22 (range: 72-100) and VAS (0.8 ± 1.22 (range: 0-5) compared to Group 2, AOOS (84.25±8.34 (range: 63-100); AOFAS (84.75±8.05 (range: 58-100) and VAS (1.7 ± 1.38 (range: 0-6). Osteosynthesis of the posterior malleolus fragment significantly reduced the frequency of trans-syndesmotic screw (0%) compared to non-osteosynthesis posterior malleolus fragment (15.9%) (p < 0.05). The EQ-5D score was better in group 1 (1.08±0.27 (range: 1-2.2) compared to group 2 (1.27 ± 0.27 (range: 1-2.4) but with no statistical significance (p> 0.15).

CONCLUSION

Posterior malleolus fragments (<25% of the articular surface) have significantly better clinical outcomes and significant decrease in trans-syndesmotic screw need following osteosynthesis.

Anatomic structures at risk in anteroposterior screw fixation of posterior malleolar fractures: A cadaver study

INTRODUCTION

Percutaneous anterior-posterior (AP) screw is an option for posterior malleolus fracture fixation when the fracture fragment can be reduced indirectly by the mean of ligamentotaxis. However, anterior anatomic structures could be injured during screw placement.

MATERIALS AND METHODS

Eleven below-knee cadavers were employed for the placement of AP screws in an attempt of fixing assumed Haraguchi Type-I posterior malleolar fractures. Three entry points were selected as medial to the anterior tibial tendon (ATT), lateral to the ATT, and lateral to the extensor digitorum longus (EDL). Three AP screws were placed under guidance of fluoroscopy. After dissection, measurements were made (mm) from each screw to nearby structures. Distances were calculated and damage to structures was documented.

RESULTS

Mean, minimum, and maximum distances from the medial screw to the greater saphenous vein, TA, EHL, anterior tibial artery (ATA), and deep peroneal nerve (DPN), were 18.1 (12-25) mm, 2.0 (0-5) mm, 13.6 (9-20) mm, 16.6 (9-25) mm, and 20.1 (12-27) mm. From the middle screw to the ATA, DPN, TA, EHL, and EDL, were 1.2 (0-3) mm, 4.9 (3-9) mm, 3.8 (1-7) mm, 0.4 (0-2) mm, and 13.6 (10-18) mm. From the lateral screw to the superficial peroneal nerve (SPN), EDL, DPN, and ATA, were 10.8 (0-16) mm, 1.2 (0-4) mm, 15.9 (11-25) mm, 19 (15-27) mm. The SPN was found partially cut by the lateral screw on 1 specimen.

CONCLUSIONS

Lateral and middle percutaneous AP screw placement put certain anatomic structures at-risk of injury. Medial screw placement did not result in appreciable damage to adjacent structures. Entry point of AP screws should be selected with respect to posterior malleolar fracture and anatomic structures.

LEVEL OF EVIDENCE

IV.

Posterior approaches to the ankle - an analysis of 3 approaches for access to the posterior malleolar fracture

BACKGROUND

An anatomical study to determine what degree of access to the posterior distal tibia could be gained by using 3 different approaches; the posterolateral, the posteromedial and the medial posteromedial approaches.

METHODS

A comparison study, between the anatomical dissection of 7 fresh frozen cadaveric lower legs and image analysis of CT data of posterior malleolar fractures from a prospectively collected database was conducted. All fractures have been classified using the Mason and Molloy classification.

RESULTS

In comparing the posterior malleolar fracture fragment width to distal tibia width, the posterolateral fragment encompasses 60.1% (95% CI 56.8, 63.3) of the total width of the tibia. If the posteromedial fragment is included the fragments encompass the entire distal tibia (100%). In type 3 fractures, 81.4% (95% CI 75.5, 87.1) of the distal tibia width is involved. When comparing the fracture width to the approach, no approach achieves a complete exposure of the type 2B or 3 fracture patterns. The overall surface area of the type 2B and 3 fractures, is significantly greater than all the approaches. Considering the lateral to medial extent of the fracture, the posterolateral fragment mean width is 33% greater than what can be exposed by the posterolateral approach (mean 24.9 vs 16.8mm). In type 2B and 3 fractures, the horizontal exposure reduces to 39.8% and 47.6% respectively. In comparison, the PM approach exposes 47.6% of the type 2B fracture pattern and 57.1% of the type 3 fracture pattern and allows a preferable angle for hardware insertion. The MPM approach does not expose any of the posterolateral fragments in this study, however it does expose 92% (mean 21.9 vs. 23.8mm) of the medial to lateral width of a posteromedial fragment of a type 2B fracture.

CONCLUSION

Each approach allows access to different parts and amounts of the posterior tibia. An understanding of and utilisation of these approaches can lead to adequate exposure for fixation of most posterior malleolus fracture patterns seen.

Clinical and radiological mid- to long-term results after direct fixation of posterior malleolar fractures through a posterolateral approach

BACKGROUND

Direct fixation of posterior malleolar fractures has been shown to lead to higher accuracy of fracture reduction compared to an indirect anterior to posterior fixation but lacks long-term clinical results. This study shows the mid- to long-term clinical and radiological outcome after direct fixation of the posterior malleolus through a posterolateral approach.

MATERIALS AND METHODS

Thirty-six patients with an ankle fracture including a posterior malleolar fragment (23 × AO-44C, 12 × AO-44B, 1 × unclassifiable) treated with direct fixation of the fragment through a posterolateral approach were retrospectively evaluated. There were 24 females (67%) with a mean age of 63 (range 34-80) years and a BMI of 28 (range 19-41) kg/m² at the time of surgery. An initial fracture-dislocation was seen in 67%. The clinical outcome was assessed with the Visual Analog Scale (VAS, 0-10 points) and the American Foot and Ankle Society (AOFAS, 0-100 points) score. Posttraumatic osteoarthritis was recorded with the Van Dijk Classification (grade 0-III). Subgroup analyses of patient- and fracture-associated risk factors (age, BMI, smoking, fracture-dislocation, postoperative articular step-off) were assessed to reveal possible negative prognostic predictors.

RESULTS

After a mean follow-up of 7.9 (range 3-12) years, the median VAS was 1 (IQR 0-2) point, and the median AOFAS score was 96 (IQR 88-100) points. Ankle range of motion measurements showed a significant, but clinically irrelevant, difference in plantar- and dorsiflexion between the affected and unaffected ankle. 92% of the patients were very satisfied or satisfied with the postoperative course. 89% had no preoperative signs of ankle osteoarthritis. Osteoarthritis progression was seen in 72%, with 50% showing grade II or III osteoarthritis at the final follow-up. No significant negative prognostic factors for a worse clinical outcome could be detected.

CONCLUSION

Direct fixation of posterior malleolar fractures through a posterolateral approach showed good clinical mid- to long-term results with a high satisfaction rate but substantial development of posttraumatic ankle osteoarthritis. Further studies should include CT analysis of the preoperative fracture morphology and even, perhaps, the postoperative reduction accuracy to evaluate the benefit of posterior malleolar fracture reduction in preventing ankle osteoarthritis in the long term.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for authors for a complete description of levels of evidence.

Comparison of the efficacy of posterior-anterior screws, anterior-posterior screws and a posterior-anterior plate in the fixation of posterior malleolar fractures with a fragment size of ≥ 15 and < 15

Background

Different fixation methods have been used to treat posterior malleolar fractures (PMFs), but the clinical efficacy of different fixation methods in the treatment of PMF with different fragmentation has rarely been reported. The purpose of this study was to investigate the efficacy of posterior-anterior (PA), anterior-posterior (AP) screws and PA plate in the fixation of PMFs with a fragment size of ≥15 and < 15%.

Methods

This is a retrospective study of the clinical data of 243 patients with a unilateral ankle fracture involving the posterior malleolar ankle fracture. All patients were divided into two groups based on their fragment size, ≥15% (n = 136) and < 15% (n = 107). After reduction of PMF under direct vision via a posterolateral approach, posterior-anterior (PA), anterior-posterior (AP) screws and PA plate were used for fixation of PMF in the two groups. Briefly, for fixation of PMF with PA screw, two to three 3.5-mm (Depuy Synthes, Switzerland) cannulated screws were placed from the posterior to anterior direction; for fixation with PA plate, a 3.5-mm reconstruction plate (Depuy Synthes, Switzerland) was placed from the posterior to anterior direction, and for fixation of PMF with an AP screw, two to three 3.5-mm screws were placed from the anterior to posterior direction. All patients were followed up at 1, 3, 6, and 12 months after surgery and thereafter at 6-month intervals. The primary outcomes were AOFAS and ROM, which were recorded at the final follow-up.

Results

The average follow-up time for all patients was 18.9 months (range 12–36 months), and all fractures healed. In fragment size ≥15% group, the average AOFAS score of patients treated with PA, AP screws and posterior plate were 91.5, 91.8, and 90.8, respectively, and the average limited ankle-dorsiflexion ROM was 5.0 °, 5.4 ° and 5.6°, respectively, at the last follow-up, there was no significant difference between the three fixation methods in terms of AOFAS scores and ankle ROM (P > 0.05). In fragment size < 15% group, the average AOFAS score of patients treated with PA, AP screws and posterior plate were 92.3, 91.9, and 84.1, respectively, the average limited ankle-dorsiflexion ROM were 5.1 °, 4.7 °, and 6.3 °, respectively, at the last follow-up. There were statistically significant differences in AOFAS scores and ankle ROM between posterior plate fixation and PA, AP screw fixation (P < 0.05); while no significant difference was found between PA and AP screw fixation (P > 0.05).

Conclusion

For PMFs with fragment size ≥15%, there was no significant difference in the outcomes between the three fixation methods. For PMF with fragmentation < 15%, the PA and AP screws both provided good fixation.

Posterior malleolar fractures: A CT guided incision analysis

AIM

The aim of this study was to determine the most appropriate approaches for fixation of each type and fragment of posterior malleolar fractures.

MATERIALS AND METHODS

A retrospective analysis of a prospectively collected database was performed on 141 posterior malleolar fractures. On the CT scan axial slice, a clock face was drawn using the posterolateral corner of the tibia as the centre and the Achilles tendon as the 6 o'clock axis. A box was then drawn from the fracture plane, with 90-degree lines corresponding to the medial perpendicular line (MPL) and lateral perpendicular line (LPL) extremity of the fracture and a central perpendicular line (CPL) (i.e. orthogonal central plane, for optimum screw placement). It was recorded where the MPL, LPL and CPL exited the clock face. All fracture patterns were further assessed by both senior authors regarding their choice of approach based on CPL and all variances resolved by discussion.

RESULTS

The LPL was equivalent across the groups (except for the 2B medial fragments), indicating a consistent posterolateral corner fragment throughout the posterior malleolar sub types (p = 0.25). The medial aspect (MPL) of the type 1, type 2A and posterolateral fragments of type 2B were equivalent. The MPL of type 3 fractures was significantly more medial than type 1 and 2A fractures (p < 0.05), with the medial extremes of the type 2B posteromedial fragment being further medial. The majority of type 2B fractures (2/3rds) were determined to be best accessed through a combined posterolateral and medial posteromedial approach, with the other third via the posteromedial approach. Almost all type 3 fractures could be appropriately accessed through the PM approach.

CONCLUSION

This study concludes that the extent of each subtype of posterior malleolar fractures are consistent. To fully expose each fracture differing incisions are necessary and should be in the skill mix for surgeons treating these fractures.

LEVEL OF EVIDENCE

4.

Mechanism of posterior malleolar fracture of the ankle: A cadaveric study

Objectives:

Ankle fracture treatment involves reduction of the bone fragments and stabilization of the joint by reversing the mechanics of injury. For posterior malleolar fracture however, the true mechanism is not understood, leading to a lack of consistent guidance on how to best treat this injury.

Methods:

Fifteen cadaver ankles were subjected to fracture loading that replicated the Lauge-Hansen pronation-external rotation mechanism. An axial load was applied to each specimen, which was mounted on a materials testing machine, and the foot was rotated externally to failure. Digital video cameras recorded the failure sequence of specific anatomic structures.

Results:

Posterior malleolar fracture occurred in 7 specimens. Of these, 1 was an intra-articular fracture, another was a fracture involving the entire posterior tibial margin consisting of 2 fragments: that of the posterior tubercle and that of the posteromedial margin of the tibial plafond, with the former judged to be a consequence of avulsion by the posterior inferior tibiofibular ligament and the latter a consequence of axial loading from the talus. In the remaining 5 specimens, the posterior malleolar fracture was a small extra-articular avulsion fracture.

Conclusions:

Fractures at the posterolateral corner of the distal tibia were shown to be avulsion fractures attributed to the posterior inferior tibiofibular ligament and produced by external rotation of the talus. A fracture involving the entire posterior tibial margin consisting of 2 fragments can be produced by a combination of avulsion by the posterior inferior tibiofibular ligament and axial loading from the talus.

Functional outcome and general health status after plate osteosynthesis of posterior malleolus fractures - The quest for eligibility

INTRODUCTION

The necessity for reduction and fixation of posterior malleolus fractures remains under debate. Therefore, we assessed the functional outcome and quality after plate osteosynthesis of the posterior malleolus, identified the main drivers of outcome and aimed to determine which patient and fracture type are eligible for plate osteosynthesis of the posterior malleolus.

MATERIALS AND METHODS

A prospective patient cohort of 50 patients with an ankle fracture including the posterior malleolus underwent plate osteosynthesis via a posterior approach, and was compared to a retrospective patient cohort of 85 consecutive patients who did not. Twenty-five demographic, operative and postoperative characteristics were assessed. Outcome was recorded using questionnaires: AOFAS, EQ-5D, EQ-5D-VAS, EQ-5D-TTO, sensory nerve-associated complications, and flexion deficit of the hallux.

RESULTS

Direct reduction and plate osteosynthesis of posterior malleolus fractures was inferior to non-operative treatment. Subanalysis of trimalleolar fractures revealed that the outcome of plate osteosynthesis was equal. Both fracture type and plate osteosynthesis were independent drivers of the outcome; Haraguchi type 3 posterior malleolus fractures were associated with the best functional outcome and quality of life scores. Comorbidity, age, postoperative complications and reintervention largely determined the outcome. Up to 30% of the patients reported (temporarily) flexion deficit of the hallux and 38% numbness at the lateral side of the foot.

CONCLUSIONS

There is no indication for routine plate osteosynthesis of all posterior malleolus fractures. Careful patient selection, less invasive surgery and modified postoperative rehabilitation seem mandatory to improve the outcome and prevent adverse effects.

Numerical Simulation of the Posterior Malleolus Fracture with the Finite Element Method

The high demand for biodegradable implants in bone fracture fixations has dramatically increased the use of polymers for biomedical applications as well. However, the replacement of stainless steel and titanium screws by biodegradable materials represents one of the most critical aspects of biomechanics. In this study, the mechanical behavior of polycaprolactone (PCL) in tension and compression is examined. Driven by the advanced technology of computational mechanics, the fixation of the posterior malleolus fracture has been designed and analyzed. The core idea depicts the static analysis of screws made of PCL fixed in the ankle joint. The focus of the study is on this bio-absorbable, polymer-based material performance under constant compression. Parametric analysis is employed for the optimization of the PCL scaffold. Future studies will focus on the experimental verification of the numerical analysis results.

Posterior malleolus fractures in Bosworth fracture-dislocations. A combination not to be missed

OBJECTIVES

Posterior malleolar fractures (PM) have been linked to inferior outcome in malleolar fractures. This study aims to analyze the prevalence and pathoanatomy of PM fractures in Bosworth fracture-dislocations (BF).

MATERIALS & METHODS

Radiographs and computed tomography (CT) scans of 13 patients treated at our institution and 97 cases published between 1947 and 2018, identified in a systematic literature search, were evaluated with respect to the pathoanatomy of BF. In all 13 cases from the present study and in 10 cases from the literature, axial CT scans were performed.

RESULTS

All 13 patients (100%) with BF from the present series and 61 of 97 documented cases (63%) of BF from the literature were associated with a PM fracture. In patients with a complete CT analysis, dislocation of the fibula behind the posterior tibial rim was associated with extraincisural (Bartoníček / Rammelt type 1) PM fractures. Displacement of the fibula between the displaced PM fragment and the tibia was associated with Bartoníček / Rammelt types 2 and 3 PM fractures.

CONCLUSIONS

Seventy prevent of all reported BF are associated with a PM fracture. The true prevalence may be even higher because of the historically infrequent use of CT imaging. The pathoanatomy of the PM fragment is highly variable as is the kind of fibular displacement in BF. Therefore, CT scanning should be performed routinely in BF. Displaced PM fractures in BF involving the incisura should be treated operatively via a direct posterolateral approach.

CT Analysis of the Posteromedial Fragment of the Posterior Malleolar Fracture

BACKGROUND

To date, there have been no studies describing the characteristics of posteromedial fragment in the posterior malleolus fracture. The aim was to investigate the variability of posteromedial fracture fragments to enable better surgical planning.

METHODS

All Mason and Molloy type 2B fractures, defined as fracture of both the posterolateral and the posteromedial fragments of the posterior malleolus, from our database were identified to analyze the preoperative computed tomography scan. The posteromedial fragment was investigated in 47 cases (mean age, 46.6 years; 11 male, 36 female).

RESULTS

Morphologically, the fracture could be divided into 2 subtypes: (1) a large pilon intra-articular fragment (mean of X axis: 33.0 mm, Y: 30.7 mm, Z: 31.7 mm) presented in 29 cases with mean interfragmentary angle of 32.1 and back of tibia angle of 32.7 degrees (this was seen in 25 of 27 cases with supination injury pattern); and (2) a small extra-articular avulsion fragment (mean of X axis: 9.6 mm, Y: 13.2 mm, Z: 11.5 mm) present in 18 cases with a mean interfragmentary angle of 11.0 and back of tibia angle of 10.1 degrees. It was seen in 80% of pronation injuries.

CONCLUSION

The avulsion type of the posteromedial fragment of posterior malleolus fracture was more common in pronation injuries, likely the result of traction by the intermalleolar ligament, and the pilon type was more common in supination injuries, likely the result of the rotating talus impaction. Because of the intra-articular involvement, we believe the pilon type should undergo fixation to achieve articular congruity, unlike the avulsion type which may only function as a secondary syndesmotic stabilizer.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Posterior Malleolar Ankle Fractures: An Effort at Improving Outcomes

BACKGROUND

There is increasing acceptance that the clinical outcomes following posterior malleolar fractures are less than satisfactory. We report our results of posterior malleolar fracture management based on the classification by Mason and Molloy.

METHODS

All fractures were classified on the basis of computed tomographic (CT) scans obtained preoperatively. This dictated the treatment algorithm. Type-1 fractures underwent syndesmotic fixation. Type-2A fractures underwent open reduction and internal fixation through a posterolateral incision, type-2B fractures underwent open reduction and internal fixation through either a posteromedial incision or a combination of a posterolateral with a medial-posteromedial incision, and type-3 fractures underwent open reduction and internal fixation through a posteromedial incision.

RESULTS

Patient-related outcome measures were obtained in 50 patients with at least 1-year follow-up. According to the Mason and Molloy classification, there were 17 type-1 fractures, 12 type-2A fractures, 10 type-2B fractures, and 11 type-3 fractures. The mean Olerud-Molander Ankle Score was 75.9 points (95% confidence interval [CI], 66.4 to 85.3 points) for patients with type-1 fractures, 75.0 points (95% CI, 61.5 to 88.5 points) for patients with type-2A fractures, 74.0 points (95% CI, 64.2 to 83.8 points) for patients with type-2B fractures, and 70.5 points (95% CI, 59.0 to 81.9 points) for patients with type-3 fractures.

CONCLUSIONS

We have been able to demonstrate an improvement in the Olerud-Molander Ankle Score for all posterior malleolar fractures with the treatment algorithm applied using the Mason and Molloy classification. Mason classification type-3 fractures have marginally poorer outcomes, which correlates with a more severe injury; however, this did not reach significance.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Open reduction and internal fixation of the posterior malleolus fragment frequently restores syndesmotic stability

AIM

Comparison of unfixed, CRIF, and ORIF of the posterior malleolus fragment (PMF) regarding the frequency of trans-syndesmotic fixation and quality of reduction in trimalleolar (equivalent) fractures.

MATERIAL AND METHODS

Retrospective registry study. Patients with a trimalleolar (equivalent) ankle fractures were identified within the departments' fracture database. General demographics, treatment details, and fracture specific details (CT-scans) were assessed. Patients were grouped per the PMF treatment: not addressed, CRIF, ORIF.

RESULTS

236 patients (53.0 ± 18.3 (range: 18-100) years), 58.1% female were eligible. The mean size of the PMF was 21.4 ± 10.4% (range: 2.7-55.9%), 71.6% were ≤25% of the tibial plafond. PMF fixation: Untreated 48.3%, CRIF 18.6%, ORIF 33.1%. ORIF of the PMF significantly (p < 0.001) reduced the frequency of trans-syndesmotic fixation (25%) compared to CRIF (61%) or untreated PMF (63%) with no significant influence of the PMF size (≤25%/>25%). ORIF resulted in a significantly (p < 0.001) better quality of reduction (1.2 ± 1.1 mm (range: 0-5 mm)) compared to CRIF (2.5 ± 2.1 mm (range: 0-8 mm)) and untreated PMF (2.5 ± 2.3 mm (range: 0-20 mm)). Neither the frequency of trans-syndesmotic fixation nor the quality of reduction differed significantly between untreated PMF and CRIF.

CONCLUSION

All posterior malleolus fragments, independent of their size, should be treated by ORIF, as this restores syndesmotic stability significantly more often than untreated PMF or CRIF.

Persistent postoperative step-off of the posterior malleolus leads to higher incidence of post-traumatic osteoarthritis in trimalleolar fractures

BACKGROUND

Traditionally, size of the posterior fragment is considered the most important indicator for fixation in trimalleolar fractures. It remains unclear which factors contribute to worse functional and radiological outcome. This study was designed to determine predictors for the development of posttraumatic osteoarthritis and worse functional outcome in trimalleolar fractures.

METHODS

This retrospective cohort study evaluated outcomes of 169 patients with a trimalleolar fracture treated between 1996 and 2013 in a level-1 trauma hospital in the Netherlands after a mean follow-up of 6.3 (range 2.4 to 15.9) years. The average fragment size was 17%. Twenty patients had a posterior fragment smaller than 5% of the intra-articular surface, 119 patients a fragment of 5-25% and 30 patients a posterior fragment larger than 25%. In total, 39 patients (23%) underwent fixation of the posterior fragment.

RESULTS

Clinical union was achieved in all 169 patients. The median AOFAS score after follow-up was 93 (interquartile range 76-100) and the median AAOS score was 92 (interquartile range 81-98). A persistent postoperative step-off larger than 1 mm was found in 65 patients (39%) and osteoarthritis was present in 49 patients (30%). Higher age and postoperative step-off > 1 mm were independent, significant risk factors for the development of osteoarthritis. Osteoarthritis and BMI were independent, significant risk factors for worse functional outcome.

CONCLUSION

It is advisable to correct intra-articular step-off of intraarticular posterior malleolar fragments to reduce the risk of developing osteoarthritis and, consequently, the risk of worse functional outcome after long-term follow-up.

LEVEL OF EVIDENCE

Level IIB.

When and how to operate the posterior malleolus fragment in trimalleolar fractures: a systematic literature review

OBJECTIVES

Whether or not and how to fixate the posterior malleolus fracture seems to depend on the fracture fragment size and its amount of dislocation, but clear guidelines for daily practice are lacking. In this review, we summarize the literature on preferred treatment of the posterior fragment in trimalleolar fractures.

METHODS

A systematic review of publications between January 1995 and April 30 2017 on this topic in the PubMed, Embase, and Cochrane databases was performed according to the PRISMA statement.

RESULTS

Seventeen (2 prospective and 15 retrospective) of the 180 identified studies were included. Six studies report on indications for fixation of posterior malleolus fracture fragments. Eleven studies compare different fixation approaches and techniques for the posterior fragment. Meta-analysis was not possible due to varying fixation criteria and outcomes. There was no clear association between posterior fragment size and functional outcome or development of osteoarthritis. The non-anatomical reduction of the fragment was of more influence on outcome. Radiological and functional outcome was better after open reduction and internal fixation via the posterolateral approach than after percutaneous anterior-to-posterior screw fixation.

CONCLUSION

The posterior fragment size is not a clear indication for its fixation. A step-off, however, seems an important indicator for developing posttraumatic osteoarthritis and worse functional outcome. Posterior fragments involving the intra-articular surface need to be reduced and fixated to prevent postoperative persisting step-off. Furthermore, fixation of the posterior malleolus via an open posterolateral approach seems superior to percutaneous anterior-to-posterior fixation. However, these results need to be confirmed in a prospective comparative trial.

LEVEL OF EVIDENCE

Therapeutic level II.