Supination adduction ankle fractures: Ankle fracture or pilon variant?

Fractures of the peroneal malleolus: Current concepts

Ankle fractures represent up to 9% of all fractures, with an increased incidence in the elderly population. Among these fractures, isolated fractures of the lateral malleolus are the most common, representing 65-70% of all cases. The therapeutic decision-making primarily relies on the stability of the ankle ring, considering it stable if affected at one point and unstable if two or more points are affected. Surgical treatment focuses on restoring the length of the fibula, joint reconstruction, stabilizing the syndesmosis, and providing a stable fixation. It is crucial to rule out associated injuries that may influence therapeutic management. This article reviews the evaluation and management of lateral malleolus fractures, proposes a decision-making algorithm, and examines several fibular fixation options.

[Translated article] Fractures of the peroneal malleolus: Current concepts

Ankle fractures represent up to 9% of all fractures, with an increased incidence in the elderly population. Among these fractures, isolated fractures of the lateral malleolus are the most common, representing 65-70% of all cases. The therapeutic decision-making primarily relies on the stability of the ankle ring, considering it stable if affected at one point and unstable if two or more points are affected. Surgical treatment focuses on restoring the length of the fibula, joint reconstruction, stabilising the syndesmosis, and providing a stable fixation. It is crucial to rule out associated injuries that may influence therapeutic management. This article reviews the evaluation and management of lateral malleolus fractures, proposes a decision-making algorithm, and examines several fibular fixation options.

A morphological review of medial malleolar fractures - A large single centre series

BACKGROUND

Many approaches to management of medial malleolar fractures are described in the literature however, their morphology is under investigated. The aim of this study was to analyse the morphology of medial malleolar fractures to identify any association with medial malleolar fracture non-union or malunion.

METHODS

Patients who had undergone surgical fixation of their MMF were identified from 2012 to 2022, using electronic patient records. Retrospective analysis of their preoperative, intraoperative, and postoperative radiographs was performed to determine their morphology and prevalence of non-union and malunion. Lauge-Hansen classification was used to characterise ankle fracture morphology and Herscovici classification to characterise MMF morphology.

RESULTS

A total of 650 patients were identified across a 10-year period which could be included in the study. The overall non-union rate for our cohort was 18.77% (122/650). The overall malunion rate was 6.92% (45/650). Herscovici type A fractures were significantly more frequently mal-reduced at time of surgery as compared to other fracture types (p = .003). Medial wall blowout combined with Hercovici type B fractures showed a significant increase in malunion rate. There is a higher rate of bone union in patients who had been anatomically reduced.

CONCLUSION

The morphology of medial malleolar fractures does have an impact of the radiological outcome following surgical management. Medial wall blowout fractures were most prevalent in adduction-type injuries; however, it should not be ruled out in rotational injuries with medial wall blowouts combined with and Herscovici type B fractures showing a significant increase in malunions. Herscovici type A fractures had significantly higher malreductions.

LEVEL OF EVIDENCE

Level 3 - Retrospective Cohort Study.

Does a rupture of the lateral ankle ligament need to be repaired in supination-adduction type II (OTA/AO 44A2) fractures?

PURPOSE

To evaluate the outcomes of patients with supination-adduction (SAD) type II (OTA/AO 44A2) fractures who had a lateral ankle ligament rupture repaired compared with patients who did not have a lateral ankle ligament repaired using patients who underwent fibula fracture fixation as a control group.

METHODS

A retrospective analysis of all 104 patients diagnosed with SAD type II fractures from January 2011 to December 2020 and managed operatively was performed. The patients were divided into three groups: 32 patients with ruptures of the lateral ligaments that were not repaired (group A), 34 patients with ruptures of the lateral ligaments that were repaired (group B), and 38 patients with fibula fracture fixation acting as the control group (group C). The objective outcomes including radiographic findings, the ankle range of motion, the manual ankle stress tests, and complications were gained from the record of the last time in outpatient clinics. The functional outcomes including the identification of functional ankle instability (IdFAI) scores were collected postoperatively at 12-month intervals to assess clinical outcomes. The Manchester Oxford Foot Questionnaire (MOXFQ) and Karlsson scoring scale were also recorded at the last follow-up.

RESULTS

The mean follow-up of the objective and subjective functional outcomes was 23.4 (range, 13-42) and 76.9 (range, 25-134) months, respectively. There was no significant difference in the radiographic findings, the ankle range of motion and complications between the three groups. All ankles were found to be stable using the manual ankle stress test in both group A and group B. The IdFAI scores showed a significant difference between group A and group B (1.12 ± 1.3 vs 0.35 ± 0.69; p < 0.001) in the first year of follow-up and no significant difference after the first year. No differences were noted in MOXFQ scores or Karlsson scores among the groups.

CONCLUSION

Directly repairing the lateral ligament could minimize the proportion of the first year of postoperative functional ankle instability, although the final stability of the ankle and clinical outcomes were not significantly different in SAD type II fractures.

LEVEL OF EVIDENCE

Level III, retrospective comparative case series.

Effect of buttress plate in Herscovici type D vertical medial malleolar fractures and peripheral fractures: a retrospective comparative cohort study

BACKGROUND

The purpose of current retrospective study was to review the surgical methods and to evaluate the clinical efficacy of supporting plate for the treatment of vertical medial malleolus fractures on the basis of stable fixation of ipsilateral fibula.

METHODS

This retrospective study included a total of 191 patients with vertical medial malleolus fractures. Patients enrolled were divided into simple vertical medial malleolus fractures and complex types of fractures. General demographic information and surgical information, including age, sex, surgical procedure and postoperative complications, were collected. The functional prognosis of patients was evaluated by American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score (AOFAS) and Visual Analog Scale (VAS).

RESULT

Among patients with simple vertical fractures, the respective incidence of internal fixation failure in screw group, buttress plate group, and screw combined buttress plate fixation group (combined fixation group) was 10/61 (16.4%),1/54 (7.4%) and 1 (1.9%), and the difference was statistically significant (P = 0.024). The incidence of abnormal fracture growth and healing in screw group, buttress plate group and combined fixation group was, respectively, 13/61 (21.3%), 6/54 (12.5%) and 2 (3.85%), with statistically significant difference (P = 0.019). In the patients with complex types of fractures, after 2 years of postoperative follow-up, the AOFAS score and VAS score of the following subgroups had good results: 91.18 ± 6.05 and 2.18 ± 1.08 in patients with joint surface collapse, and 92.50 ± 4.80 and 2.50 ± 1.29 in patients with tibial fractures, with 100% excellent and good rate.

CONCLUSION

For simple and complex vertical medial malleolus fractures, buttress plate showed excellent fixation. Despite poor wound healing and extensive soft tissue dissection with this approach, buttress plate may provide a novel insight into medial malleolar fractures, especially for extremely unstable medial malleolar fractures.

Outcomes of tibial pilon fracture fixation based on four-column theory

OBJECTIVES

To assess the medium-term functional and radiological outcomes, as well as injury mechanisms, fracture patterns and demographics of typical pilon fractures and pilon variant fractures treated based on the four-column theory in adults.

METHODS

A retrospective comparative study was performed. Demographics of typical pilon and pilon variant fractures, injury mechanisms, OTA/AO classification, Rüedi-Allgöwer and the four-column classification were analyzed for the cohort. Radiographic ankle arthrosis (modified Kellgren-Lawrence 3/4), Burwell Charnley Score, and AOFAS score were also analyzed.

RESULTS

There were 142 pilon fractures met the inclusion and exclusion criteria for this study, of which 77(54.23%) were females and 65 (45.77%) were males, with an average of 48 (range, 18-86)years. One hundred twenty-five posterior columns fractured in 142 pilon fractures, and the posterior columns were most prone to fractures. Ninety cases of posterior pilon fractures in 142 pilon fractures were single posterior column fractures with or without medial or lateral malleolar fractures. The average age (51, range, 18-86 years) of low-energy pilon fractures was older than the average age (42, range, 19-66 years) of high-energy pilon fractures significantly. The average time (5, range, 0-17 days) from injury to definitive internal fixation of the low-energy group was shorter than the average time (9, range, 0-21 days) from injury to definitive internal fixation of the high-energy group significantly. The average of AOFAS (87, range, 56-100) of the low-energy group is higher than the average of AOFAS (82, range, 47-100) of the high-energy group significantly. There were more male patients and more die-punch or intercalary fractures in high energy groups significantly. There were more medial and lateral malleolar fractures in low-energy groups. Compared with the non-multiple column group, the multiple-column group had more Rüedi-Allgöwer type III cases, more modified Kellgren-Lawrence 3/4 cases and lower AOFAS score significantly. However, the numbers of Burwell Charnley Score type 1 and 2 cases were not significantly different between the two groups.

CONCLUSIONS

Kinds of pilon variants should be recognized. Outcomes of high-energy pilon fractures were worse than low-energy pilon fractures. The four-column theory can be applied to typical pilon fracture and pilon variants in adults.

Supination Adduction Vertical Medial Malleolar Fracture Fixation with Buttress Plating vs a Novel Screw-Only Construct: A Cadaveric Biomechanical Study

BACKGROUND

Supination adduction ankle fractures are unique among rotational ankle fractures as plate constructs are more commonly used than independent screws for medial malleolar fixation. The purpose of this study was to compare fracture displacement between plate fixation to a novel screw-only construct using a cadaveric biomechanical early-weightbearing model for the treatment of vertical medial malleolus fractures.

METHODS

Six nonosteoporotic fresh-frozen cadaver shanks and feet in matched pairs underwent a vertical osteotomy of the medial malleolus to simulate the supination adduction type injury. Osteoporosis was measured using DEXA scans. One specimen from each pair was fixed with a one-third tubular buttress plate and the other with screw-only fixation. The specimens were then axially loaded for 100 000 cycles to simulate protected weightbearing, and subsequently loaded to failure in supination. Stiffness, fracture displacement, and load to failure were recorded. Statistical significance was set at P <.05.

RESULTS

There were no measurable differences in displacement between the 2 constructs during axial cyclic loading after 100 000 cycles (plate, 0.74 ± 0.09 mm; screws, 0.79 ± 0.18 mm; P = .225). During supination and axial load to failure, the plate outperformed the screw construct. For load to failure (2 mm displacement) at the fracture site, the plate group failed at 716 ± 240 N, whereas the screw group failed at 567 ± 237 N (P = .015). During load to catastrophic failure, the plate group outperformed the screw group (plate, 6011 ± 1646 N; screws, 4578 ± 1837 N; P = .002).

CONCLUSION

For vertical medial malleolar fractures, the screw-only construct demonstrated no statistical difference when compared to buttress plating for cyclical axial loading, simulating early weightbearing in a boot. However, buttress plating is 21% to 24% stronger than the screw-only fixation construct in overall strength and prevention of catastrophic failure when loading in a supinated position.

CLINICAL RELEVANCE

The screw-only construct is biomechanically similar to a buttress plate when simulating early protected weightbearing. This suggests that early weightbearing as tolerated in a controlled ankle motion boot beginning 2 weeks postoperatively is mechanically safe for this fracture pattern and does not result in unacceptable amounts of fracture displacement. This construct may be useful as a less invasive treatment modality for the treatment of vertical medial malleolus fractures in select patients.

Joint Preservation for Posttraumatic Ankle Arthritis After Tibial Plafond Fracture

Management of posttraumatic ankle arthritis due to tibial plafond fracture is technically demanding. The distal tibial plafond-plasty could be an alternative to preserve the ankle joint for young patients with limited ankle arthritis. The surgical principles are to realign the mechanical axis, reconstruct the articular surface of the distal tibial plafond, and achieve a congruent and stable ankle joint. In addition to the anteroposterior view of the ankle joint, the lateral view was also paramount for surgeons to fully evaluate the reduction quality. The revision procedures are as follows: osteotomy for exposure, articular surface reconstruction, bone grafting, and osteotomy fixation.

A comparative study of the clinical efficacy of supination-adduction type II ankle fracture surgery based on the medial pilon fracture concept versus the ankle fracture concept

Background

A supination-adduction (SAD) ankle fracture is a special type of ankle fracture that results in collapse of the distal tibial articular surface; as such, orthopaedic surgeons require greater awareness of this type of fracture. The severity of this injury lies between that of an ordinary ankle fracture and a pilon fracture, and the treatment of such fractures based on the ankle fracture concept leads to extremely high rates of postoperative complications and a poor prognosis. In this retrospective study, we aimed to explore the treatment of SAD fractures based on the pilon fracture concept.

Methods

We retrospectively analysed the clinical data of 67 patients with Lauge-Hansen supination-adduction type II (SAD-II) ankle fractures, most of whom had a 44-A AO classification. Patients underwent surgical treatment at the Second Affiliated Hospital of Anhui Medical University from January 2009 to June 2019. The patients were divided into two groups based on the surgical concept employed: 43 patients were included in the ankle fracture surgical concept group, and 24 patients were included in the medial pilon fracture surgical concept group. The therapeutic effect was evaluated based on the Burwell-Charnley radiological reduction standard, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and postoperative visual analogue scale (VAS) pain score 1 year after surgery using regression with adjustment for confounding factors.

Results

All 67 patients were followed up. Twenty-four patients were treated according to the medial pilon fracture concept, and forty-three patients were treated according to the ankle fracture concept. The AOFAS score 1 year after surgery in the medial pilon group (89.83 ± 2.77) was higher than that in the ankle fracture group (83.63 ± 7.97) (p < 0.05). The VAS score 1 year after surgery in the medial pilon fracture group (1.17 ± 0.96) was significantly better than that in the ankle fracture group (2.28 ± 0.96) (p < 0.05).

Conclusion

Patients with Lauge-Hansen SAD-II ankle fractures treated based on the medial pilon fracture surgical concept had better postoperative outcomes than those treated based on the ankle fracture surgical concept.

Level of evidence

Level III, retrospective cohort study.

Plafond Malreduction and Talar Dome Impaction Accelerates Arthrosis After Supination-Adduction Ankle Fracture

BACKGROUND

Supination-adduction (SAD) type II ankle fractures can have medial tibial plafond and talar body impaction. Factors associated with the development of posttraumatic arthritis can be intrinsic to the injury pattern or mitigated by the surgeon. We hypothesize that plafond malreducton and talar body impaction is associated with early posttraumatic arthrosis.

METHODS

A retrospective cohort of skeletally mature patients with SAD ankle fractures at 2 level 1 academic trauma centers who underwent operative fixation were identified. Patients with a minimum of 1-year follow-up were included. The presence of articular impaction identified on CT scan was recorded and the quality of reduction on final intraoperative radiographs was assessed. The primary outcome was radiographic ankle arthrosis (Kellgren-Lawrence 3 or 4), and postoperative complications were documented.

RESULTS

A total of 175 SAD ankle fractures were identified during a 10-year period; 79 patients with 1-year follow-up met inclusion criteria. The majority of injuries resulted from a high-energy mechanism. Articular impaction was present in 73% of injuries, and 23% of all patients had radiographic arthrosis (Kellgren-Lawrence 3 or 4) at final follow-up. Articular malreduction, defined by either a gap or step >2 mm, was significantly associated with development of arthrosis. Early treatment failure, infection, and nonunion was rare in this series.

CONCLUSION

Malreduction of articular impaction in SAD ankle fractures is associated with early posttraumatic arthrosis. Recognition and anatomic restoration with stable fixation of articular impaction appears to mitigate risk of posttraumatic arthrosis. Investigations correlating postoperative and long-term radiographic findings to patient-reported outcomes after operative treatment of SAD ankle fractures are warranted.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Supination Adduction Ankle Fractures Are Associated With Arthritis and Poor Outcomes

OBJECTIVE

To compare complications and functional outcomes between supination adduction type II (SAD) injuries and torsional ankle injuries (TAI).

DESIGN

Retrospective cohort.

SETTING

Level 1 trauma center.

PATIENTS AND METHODS

Patients (n = 1531) treated for ankle fractures (OTA/AO 43B or 44) over 16 years were identified. The most recent 200 consecutive adult patients treated for TAI (OTA/AO 44, not SAD) served as controls.

MAIN OUTCOME MEASURES

Complications, unplanned secondary procedures, and patient-reported functional outcome scores, as measured by the Foot Function Index and Short Musculoskeletal Function Assessment.

RESULTS

Sixty-five patients with SAD injuries (4.2%) were included. They were younger (43.2 vs. 47.7 years, P = 0.08) and more commonly involved in a motorized collision, (58.5% vs. 29.0%) and more often multiply injured: other orthopaedic injuries (66.2% vs. 31.0%) and other nonorthopaedic injuries (40.0% vs. 7.5%, all P < 0.001 vs. TAI). Overall complication and unplanned secondary procedure rates were not different between groups. Those with a SAD injury had more posttraumatic arthrosis (80.0% vs. 40.9%, P = 0.004), but no differences were noted in infection, wound healing, malunion, or nonunion. The mean functional outcome scores were worse for SAD patients over 6 years after injury among all the Foot Function Index and Short Musculoskeletal Function Assessment categories; however, these differences were not significant.

CONCLUSIONS

SAD injuries represented 4.2% of all ankle fractures, occurring in younger patients through higher-energy mechanisms and more often associated with polytrauma. Despite 80% of SAD patients developing posttraumatic arthrosis, secondary procedures were not more common, and functional outcomes after a SAD injury were not different from TAI.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Characteristics and classification of medial malleolar fractures

AIMS

The morphology of medial malleolar fracture is highly variable and difficult to characterize without 3D reconstruction. There is also no universally accepeted classification system. Thus, we aimed to characterize fracture patterns of the medial malleolus and propose a classification scheme based on 3D CT reconstruction.

METHODS

We retrospectively reviewed 537 consecutive cases of ankle fractures involving the medial malleolus treated in our institution. 3D fracture maps were produced by superimposing all the fracture lines onto a standard template. We sliced fracture fragments and the standard template based on selected sagittal and coronal planes to create 2D fracture maps, where angles α and β were measured. Angles α and β were defined as the acute angles formed by the fracture line and the horizontal line on the selected planes.

RESULTS

A total of 121 ankle fractures were included. We revealed several important fracture features, such as a high correlation between posterior collicular fractures and posteromedial fragments. Moreover, we generalized the fracture geometry into three recurrent patterns on the coronal view of 3D maps (transverse, vertical, and irregular) and five recurrent patterns on the lateral view (transverse, oblique, vertical, Y-shaped, and irregular). According to the fracture geometry on the coronal and lateral view of 3D maps, we subsequently categorized medial malleolar fractures into six types based on the recurrent patterns: anterior collicular fracture (27 type I, 22.3%), posterior collicular fracture (12 type II, 9.9%), concurrent fracture of anterior and posterior colliculus (16 type III, 13.2%), and supra-intercollicular groove fracture (66 type IV, 54.5%). Therewere three variants of type IV fractures: transverse (type IVa), vertical (type IVb), and comminuted fracture (type IVc). The angles α and β varied accordingly.

CONCLUSION

Our findings yield insight into the characteristics and recurrent patterns of medial malleolar fractures. The proposed classification system is helpful in understanding injury mechanisms and guiding diagnosis, as well as surgical strategies. Cite this article: Bone Joint J 2021;103-B(5):931-938.