Open reduction in pilon variant posterior malleolar fractures: Radiological and clinical evaluation

A systematic review of posterior pilon variant fractures

Posterior pilon variant ankle fractures (PPVF) are a unique subtype of posterior malleolar fractures which have been a source of controversy and confusion in recent years. There has not been a thorough literature review previously written on the topic. Database searches of PubMed and Embase were conducted from inception until June 2023. The key words included "pilon variant," "posterior pilon variant," and "posterior pilon" fractures. Outcomes were evaluated by union time, rates of delayed union, nonunion, malunion, and complication. A total of 15 articles relevant to surgical repair of pilon variant fractures were included in the literature review. The unique mechanism of injury has been reported to involve both rotational and axial forces, leading to involvement of the posterior and medial aspects of the distal tibia. Pilon variant fractures can be suspected by several characteristics on radiographs and have a high confirmation rate via CT images. Multiple systems have been proposed to classify this fracture pattern, but there is no consensus on the ideal classification system. Surgically, direct fixation has shown better short-term clinical outcomes versus indirect fixation or no fixation. PPVF have a distinct fracture pattern involving the posterior and medial columns of the distal tibial plafond, and results from a mechanism intermediate to rotational and axial forces. These fractures are more severe than tri-malleolar fractures due to increased rates of articular impaction and incongruity. Future classification systems should focus on joint surface area and the tibial pilon column involved to avoid confusion with less severe posterior malleolar fractures.

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.

Treatment outcomes of posterior pilon fractures using a simple single lateral approach via stretching fibular fracture line

Purpose

The aim of this study was to explore the treatment outcomes of a novel single lateral approach via fibular fracture line for patients with posterior pilon fractures.

Patients and methods

From January 2020 to December 2021, a total of 41 patients with posterior pilon fractures who received surgical treatment in our hospital were retrospectively reviewed. Twenty patients (Group A) were treated with open reduction and internal fixation (ORIF) via posterolateral approach. Twenty-one patients (Group B) were treated with ORIF using a simple single lateral approach via stretching fibular fracture line. Clinical assessments, including operation time, intraoperative blood loss, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS), and the active range of motion (ROM) of the ankle at the final follow-up visit after surgery, were performed in all patients. Radiographic outcome was evaluated by using the criteria proposed by Burwell and Charnley.

Results

The mean follow-up time was 21 months (range 12-35). The average operation time and intraoperative blood loss in the Group B were significantly less than those in the Group A. Moreover, the AOFAS score and ankle ROM in the Group B were significantly higher than those in the Group A at the final follow-up visit. Eighteen cases (90%) in Group A and 19 cases (90.5%) in Group B achieved anatomical reduction of the fracture.

Conclusion

The single lateral approach via stretching fibular fracture line is a simple and effective technique for reduction and fixation of posterior pilon fractures.

Clinical Outcomes for Pilon Variant Posterior Malleolar Fractures: A Multicenter Retrospective Analysis

Currently, there is no consensus on surgical approach for posterior malleolar fracture fragments with significant posteromedial involvement. The Bartonicek type III/Haraguchi type II posterior malleolar morphologies typically involve large posteromedial fragments, behaving like a pilon injury and have been reported as pilon variant fractures. We performed a retrospective chart review at 2 large healthcare institutions, evaluating patients that underwent surgical management of pilon variant posterior malleolar fractures and determining clinical outcomes including: time to union, union rates, soft tissue complications, infection and time to weight bearing. A total of 68 patients were included (51 females, 17 males). A total of 51 direct (19 posterolateral, 31 posteromedial), 6 indirect, and 11 no-fixation approaches were identified. Significantly different time-to-union was found between direct fixation (mean = 85.1 days), indirect fixation (mean = 74 days) and no-fixation (mean = 174.3 days) (p < .001). A posteromedial approach (mean = 63.0 days, SD = 16.6) was associated with significantly shorter time to union when compared to a posterolateral approach (mean = 124.8 days, SD = 59.4; p < .001). Fixation (direct or indirect) was associated with significantly increased likelihood of union of the overall ankle fracture pattern (52/57 = 91%) when compared to no fixation of the posterior malleolar component (9/14 = 64%), p = .01. Patients who underwent direct fixation had significantly lower incidence of neurovascular damage (6%) when compared to patients who underwent indirect fixation (33%) or no-fixation (29%) (p = .02). There was no significant difference between the groups in terms of tendon damage (p = .54), infection rates (p = .45) and time to weight bearing (p = .66). The authors suggest that surgical management and specifically direct approaches have better outcomes in the short-term follow up.

The prognosis of ankle fractures: a systematic review

The aim of this study was to update the scientific evidence for ankle fracture prognosis by addressing radiographic osteoarthritis, time course and prognostic factors.

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included if they were randomized controlled trials, controlled trials or observational studies, including case series and case-control studies investigating radiologically confirmed osteoarthritis in adults with a classified ankle fracture, treated with or without surgery, with a minimum follow-up of 1 year. Also included were studies examining prognostic factors predicting radiologically confirmed osteoarthritis. Tibial plafond and talus fractures were excluded.

Thirty-four studies were included examining 3447 patients. Extracted data included study type, inclusion and exclusion criteria, age, number of patients, number of fractures according to the author-reported classification method, radiological osteoarthritis, follow-up period, prognostic factors, and treatment.

Severe heterogeneity was visible in the analyses (I² > 90%), reflecting clinical heterogeneity possibly arising from the presence of osteoarthritis at baseline, the classifications used for the fractures and for osteoarthritis.

The incidence of osteoarthritis was 25% (95% CI: 18–32) and 34% (95% CI: 23–45) for more severe fractures with involvement of the posterior malleolus.

The severity of the trauma, as reflected by the fracture classification, was the most important prognostic factor for the development of radiographic osteoarthritis, but there is also a risk with simpler injuries.

The period within which osteoarthritis develops or becomes symptomatic with an indication for treatment could not be specified.

Posterior pilon fracture treated by opening the fibula fracture gap

Background

Posterior pilon fracture is a relatively common clinical fracture involving the posterior articular surface of the distal tibia. Currently, this form of fracture is receiving increasing attention. The surgical approach and technique for the treatment of posterior pilon fractures are still controversial. The purpose of this retrospective study was to compare the clinical and imaging outcomes of pilon fractures after treatment with the open fibula fracture line (OFFL) surgical technique versus the traditional posterolateral approach (TPL).

Methods

A retrospective analysis of patients with posterior pilon fractures treated using the open fibula fracture line technique and the traditional posterolateral approach between January 2015 and March 2020. Thirty-one cases were included in the open fibula fracture line technique group and twenty-eight cases were included in the traditional posterolateral approach group. We used the Burwell-Charnley scale to assess the effectiveness of surgical repositioning. The clinical outcomes were evaluated using American Orthopaedic Foot & Ankle Society ankle-hind foot score (AOFAS) and visual analog score (VAS).

Results

The overall anatomic reduction rate was slightly better in the open fibula fracture line group than in the conventional posterolateral group (81% vs. 71%, p = 0.406), but there was no statistically significant difference between the two groups. There were no statistically significant differences between the two groups in terms of fracture healing time and time to full weight bearing (p > 0.05). At the final follow-up, the AOFAS functional score of the open fibula fracture line group was statistically superior to that of the conventional posterolateral group (p < 0.05). However, there was no statistical difference between the two groups in VAS pain scores at rest, during activity, and under weight bearing (p > 0.05).

Conclusion

The trans-fibular fracture approach provides a better surgical option for specific types of posterior pilon fractures with a high rate of anatomic repositioning and a good near-term outcome.

Trial registration: Retrospective registration.

Simultaneous Posterolateral and Posteromedial Approaches for Fractures of the Entire Posterior Tibial Plafond: A Safe Technique for Effective Reduction and Fixation

OBJECTIVE

To determine the short-term results of surgical treatment with dual posterolateral and posteromedial approaches for fractures of the entire posterior tibial plafond and secondarily to identify common fracture characteristics.

DESIGN

Retrospective.

SETTING

Single academic Level 1 trauma center.

PATIENTS

Thirty-five patients with posterior pilon fractures followed until fracture union (minimum 3 months).

INTERVENTION

Surgical treatment using simultaneous combined posterolateral and posteromedial exposures for fracture reduction and internal fixation.

MAIN OUTCOME MEASUREMENT

(1) Surgical outcomes including rate of wound complications and accuracy of the articular reduction. (2) Fracture characteristics including the incidence of articular impaction, comminution interfering with reduction, syndesmosis injury, and the type of fibula fracture.

RESULTS

The rate of wound problems was low (6%), and 94% of patients had an articular reduction with less than 1 mm of step or gap. There were high rates of articular comminution (83%) and posteromedial articular impaction (63%) and a 17% rate of syndesmosis injury requiring repair.

CONCLUSIONS

Surgical fixation using simultaneous, combined posterolateral and posteromedial approaches for posterior pilon fractures had a low rate of wound complications and was an effective strategy for obtaining an accurate reduction. The rate of syndesmotic instability requiring fixation was lower than previous work reporting on fixation using a single approach. This may be a useful technique for surgeons who treat these injuries. Careful assessment of the preoperative imaging is required in patients with posterior pilon fractures.

LEVEL OF EVIDENCE

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

Posterior-Based Approaches to Open Reduction Internal Fixation of Bimalleolar and Trimalleolar Fractures: A Systematic Review and Meta-analysis

Although there is growing evidence supporting posterior-based surgical approaches to open reduction internal fixation (ORIF) of malleolar fractures, the lateral approach still remains the standard of care for this injury. The purpose of this review was to integrate the results of several studies investigating outcomes following posterior-based approaches to the ORIF of malleolar fractures. The literature search was undertaken using PubMed, the Cochrane Library, and Embase. Crude event rates for fracture healing and postoperative complications were calculated. When possible, meta-analyses were conducted to estimate the relative risk of these outcomes between patients treated by posterior-based approaches versus other approaches to ORIF of malleolar fractures. Twenty-two studies were eligible, and 4 studies were included in the meta-analyses. The healing rate was 100% in all patients, regardless of the surgical approach. Overall, 1.26% of patients developed an infection, 0.63% required reoperation, 1.13% experienced aseptic loosening, 5.53% experienced pain after treatment, and 2.52% experienced symptomatic hardware. No malunion or heterotopic ossification was reported in any study. Among patients treated with a posterior-based approach, the most frequently reported complication was infection (2.50%), with lower rates of reoperation and postoperative pain. Patients with trimalleolar fractures experienced slightly poorer outcomes. Patients treated by posterior-based approaches had a significantly increased risk of infection (p = .010) relative to those treated by the lateral approach; patients treated by the lateral approach had a significantly increased risk of pain after surgery (p = .004) and symptomatic hardware (p = .007). This study brought together evidence that posterior-based surgical approaches and non-posterior-based approaches to ORIF are effective in healing malleolar fractures, with significant differences in specific postoperative complications that need to be further explored.

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.

Impact of two- and three-dimensional computed tomography use on intraobserver and interobserver reliabilities of pilon fracture classification and treatment recommendation

BACKGROUND

Two-dimensional (2D) and three-dimensional (3D) computed tomography (CT) have been increasingly used in various intra-articular fractures including pilon fracture. However, no study has investigated intraobserver and interobserver reliabilities of pilon fracture classification using 3D CT images.

HYPOTHESIS

(1) Intraobserver and interobserver agreements of fracture classifications and treatment recommendations will improve by using 2D CT images compared to using plain radiographs only; (2) agreements will improve by adding 3D CT images compared to adding 2D CT images; and (3) agreements of orthopedic residents rather than specialists will be influenced more by imaging modality.

MATERIALS AND METHODS

Ten orthopedic specialists and 10 residents completed a survey to classify the fractures according to the Rüedi-Allgöwer and AO/OTA classifications and to select treatment options using 25 pilon fracture images. The survey was conducted using plain radiographs, with 2D and 3D CT images introduced 3 and 6weeks later, respectively. Kappa coefficients were calculated to determine reliabilities.

RESULTS

Intraobserver reliabilities for fracture classifications in specialists significantly improved by using 2D images compared to using plain radiographs only. Addition of 3D CT did not significantly improve intraobserver reliabilities compared to those with 2D CT. Use of 2D CT images significantly improved overall interobserver agreement of both classifications, with the improvement being greater for residents. Use of 3D CT images did not improve the interobserver reliability of both classifications. Overall interobserver reliabilities for treatment recommendations did not significantly differ according to the imaging modality. However, interobserver agreement among residents significantly improved from slight agreement using radiographs only to fair agreement using 2D CT images.

DISCUSSION

Intraobserver and interobserver reliabilities of pilon fracture classification and treatment recommendations did not improve between using 3D and 2D CT. Using 2D CT images improved the intraobserver and interobserver reliabilities of the fracture classifications in specialists and the interobserver reliabilities of the fracture classifications and the treatment recommendations in residents.

LEVEL OF EVIDENCE

IV, case control study.

Clinical Outcomes of Hyperplantarflexion Variant Compared With Supination External Rotation Ankle Fractures: A Matched-Cohort Analysis

Recent literature has reported an uncategorized hyperplantarflexion variant ankle fracture characterized by a posteromedial fragment separate from the posterior or medial malleolar fragments. The current study sought to determine whether the outcomes for surgically treated hyperplantarflexion variant fractures are similar to the more common supination external rotation (SER) IV fractures. A prospective registry of operatively treated ankle fractures was queried to create 2 age- and gender-matched cohorts: hyperplantarflexion variant and SER IV fractures. Each cohort had 23 patients (18 females), and matched pairs were within 2 years of age at the date of surgery. Patient demographics, comorbidities, and Foot and Ankle Outcomes Scores at minimum 12 months after the index surgery were compared. The cohorts were similar with respect to body mass index, the length of the clinical follow-up, medical comorbidities, dislocation rate, and postoperative articular incongruity (p > .05). Patient-reported outcomes demonstrated no statistically or clinically significant differences within any domain and were as follows: symptoms (70.8 versus 77.8, p = .11), pain (80.7 versus 85.0, p = .33), activities of daily living (83.7 versus 89.2, p = .23), sports (67.4 versus 73.4, p = .33), and quality of life (57.3 versus 63.9, p = .24) for the hyperplantarflexion and SER IV groups, respectively. No significant differences were found in the rang`e of motion for dorsiflexion (17.7° versus 18.1°, p = .52) or for plantarflexion (48.6° versus 47.1°, p = .71). Patients treated surgically for hyperplantarflexion variant ankle fractures have similar 1-year clinical outcomes when compared with the more common SER IV fracture patterns, provided that the injury is correctly identified preoperatively and treated appropriately.