Radiographic Detection of Marginal Impaction in Supination-Adduction Ankle Fractures

Importance of computed tomography in posterior malleolar fractures: Added information to preoperative X-ray studies

BACKGROUND

Ankle fractures are common lesions of the lower limbs. Approximately 40% of ankle fractures affect the posterior malleolus (PM). Historically, PM osteosynthesis was recommended when PM size in X-ray images was greater than 25% of the joint. Currently, computed tomography (CT) has been gaining traction in the preoperative evaluation of ankle fractures.

AIM

To elucidate the similarity in dimensions and to correlate PM size in X-ray images with the articular surface of the affected tibial plafond in the axial view on CT (AXCT) of a PM fracture.

METHODS

Eighty-one patients (mean age: 39.4 ± 13.5 years) were evaluated (54.3% were male). Two independent examiners measured PM size in profile X-ray images (PMXR) and sagittal CT (SAGCT) slices. The correlation of the measurements between the examiners and the difference in the PM fragment sizes between the two images were compared. Next, the PM size in PMXR was compared with the surface of the tibial plafond involved in the fracture in AXCT according to the Haraguchi classification.

RESULTS

The correlation rates between the examiners were 0.93 and 0.94 for PMXR and SAGCT, respectively (P < 0.001). Fragments were 2.12% larger in SAGCT than in PMXR (P = 0.018). In PMXR, there were 56 cases < 25% and 25 cases ≥ 25%. When PMXR was < 25%, AXCT corresponded to 10.13% of the tibial plafond. When PMXR was ≥ 25%, AXCT was 24.52% (P < 0.001). According to the Haraguchi classification, fracture types I and II had similar PMXR measurements that were greater than those of type III. When analyzing AXCT, a significant difference was found between the three types, with II > I > III (P < 0.001).

CONCLUSION

PM fractures show different sizes using X-ray or CT images. CT showed a larger PM in the sagittal plane and allowed the visualization of the real dimensions of the tibial plafond surface.

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.

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.

Advantages of preoperative planning using computed tomography scan for treatment of malleolar ankle fractures

Malleolar ankle fractures have been classified using plain radiographs, and there is no consensus regarding the role of computed tomography (CT) scans in preoperative planning. We analyzed critical aspects, such as limits of standard radiographs, types of injury, classification methods and cost/benefit evaluations. CT scans allow a 3D analysis of the fracture to be obtained and consequently assess the indication for surgical procedure, surgical access and the type of fixation devices required. This exam is useful for detecting lesions that may go unnoticed on radiographs and will help surgeons to clarify the pathoanatomy of ankle fractures. According to Arbeitsgemeinschaft fur Osteosynthesefragen/ Orthopaedic Trauma Association (AO/OTA) classification, CT scan is recommended in medial malleolar fractures with vertical rim, type 44B fractures with posterior malleolar involvement and all type 44C fractures (according to AO/OTA). Also Tillaux-Chaput fractures (43-B1 according to AO/OTA), malleolar fractures in the presence of distal tibial fractures (43 according to AO/OTA) and distal tibia fractures in adolescents should be studied with CT scans.

Complications following operative treatment of supination-adduction type II (AO/OTA 44A2.3) ankle fractures

INTRODUCTION

There are few published studies that investigate the surgical treatment of supination-adduction (SAD, AO/OTA 44A2.3) ankle fractures. The purpose of this study was to describe the complications and outcomes following operative fixation of SAD type 2 ankle fractures.

MATERIALS AND METHODS

We identified all SAD-2 ankle fractures that presented at our institution's two hospitals from 2006-2018. Demographics, operative data, and complications (deep infection, superficial infection, delayed union, failure of fixation, and unplanned reoperation) were recorded for all patients. Lastly, all included patients were contacted by telephone for the administration of an 8-question Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference questionnaire (PI). Univariate and multivariate analysis was performed to identify risk factors for complication or poor functional outcome score.

RESULTS

65 patients met inclusion criteria. The average time to surgery was 14 days and average follow-up was 20.5 (range: 0.4-60.9) weeks. There were 9 (13.8%) complications (4 deep infections, 3 superficial infections, 1 delayed union, 1 failure of fixation) and 6 unplanned reoperations. Univariate and multivariate analysis failed to identify any statistically significant risk factors for complication or reoperation. Eleven patients participated in the administration of PROMIS score questionnaires at a mean of 3.4 years postoperatively. The average PROMIS Physical Function T-score was 42.3 ± 11.3 and the average PROMIS Pain Interference T-score was 55.8 ± 7.8. Younger age was associated with a higher physical function score. The use of a direct medial approach to the medial malleolus was associated with a lower pain interference score.

CONCLUSION

The overall complication rate for SAD (OTA/AO 44A2.3) type 2 ankle fractures is similar to that of the general ankle fracture population. We were unable to identify risk factors for complication or reoperation. Mean patient reported outcomes are within one standard deviation of the general population.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Supination adduction ankle fractures: Ankle fracture or pilon variant?

BACKGROUND

Supination adduction (SAD) fractures are rotational ankle fractures with a characteristic vertical medial malleolus fracture and tension failure fibula fracture. While these fractures are considered rotational injuries, they can have joint impaction that could lead to early joint degeneration. The purpose of this study was to characterize SAD ankle fractures and compare these injuries with partial articular pilon fractures.

METHODS

Following IRB approval, we retrospectively reviewed ankle and pilon fractures (OTA 43 & 44) treated at two academic level-1 trauma centers from 2008-2016. Our primary outcome was failure defined as either ankle arthrodesis or arthroplasty. Infection and significant arthrosis were also compared. We performed multivariate Cox regression to compare failure between SAD ankles and pilon fractures.

RESULTS

Seventy-nine SAD ankle and 91 pilon fractures met inclusion criteria. Patient demographics including age and open injury did not differ between groups. For SAD ankle fractures, impaction occurred in 66% (44/79) of injuries. Impaction failed to be significant risk factor for arthrosis after adjustment for malreduction (p = 0.13). Failure was significantly more common in pilon fractures (11/91, 12%) than SAD fractures (5/79, 6%) (HR=0.25, 95% CI:[0.07,0.92], p = 0.036). Infection and arthrosis rates failed to show a difference between the groups (p = 0.19, 0.63, respectively). Malreduction was significantly associated with joint arthrosis (OR=7.05, 95% CI: [1.63,36.12], p = 0.01).

CONCLUSION

Rotational ankle fractures have low rates (<2%) of ankle arthrodesis or arthroplasty. The present study demonstrates that SAD ankles have failure (6%) that remains somewhere between rotational ankle fractures and pilon fractures (12%) on the ankle injury spectrum.

LEVEL OF EVIDENCE

Level 3, Prognostic.

Anatomy, Classification, and Management of Ankle Fractures Involving the Posterior Malleolar Fragment: A Literature Review

The posterior malleolar fragment is frequently involved in rotational ankle fractures, but diagnosis and definitive management remains controversial. Ankle fractures with a posterior malleolar component that are not identified and treated in a timely manner may contribute significantly to future comorbidities, including continued pain, instability, and the development of arthritis. This article highlights the anatomic features of posterior malleolar ankle fractures, the classification schemes used, and discusses the various nonsurgical and surgical methods currently used.