Technique tip: revisit to a surgical approach to allow direct fixation of fractures of the posterior and medial malleolus

A Retrospective Study on the Morphology of Posterior Malleolar Fractures Based on a CT Scan: Whether We Ignore the Importance of Fracture Height

Objective

The aim of this study was to investigate the respective correlation between the height (H) of a posterior malleolar fracture (PMF) and the involved area (S) of an articular surface and the presence of “die-punch.”

Methods

Patients with closed posterior malleolar fractures admitted to our hospital from January 2015 to December 2017 were selected, with complete X-ray and 3D reconstruction CT imaging data. The gender, age, injured side, and surgical fixation methods of the patients were recorded. A preoperative ankle CT scan was performed, and the images were viewed through the PACS (Picture Archiving and Communication Systems). Simultaneously, the involved joint surface area (S) by the posterior malleolar fracture was measured, as well as the proportion of the fracture area to the total ankle joint area. On the sagittal reconstruction CT images, the height (H) of the posterior malleolar fracture was measured to compare the correlation between the height of the fracture and the area of the fracture, as well as the area ratio. Besides, according to the presence or absence of “die-punch,” patients were divided into two groups: A and B. And each group was further divided into three subgroups according to age (16-39 years old, 40-59 years old, and ≥60 years old). The statistical differences in the height of fracture between the subgroups were compared.

Results

A total of 48 patients, aged 16-82 years, with an average age of 48.9 years, were included in this study, including 13 males and 35 females. There were 20 cases of left ankle injury and 28 cases of right ankle injury. The average height of the posterior malleolar fractures was 18.19 mm, the average area of the fracture was 202.28 mm², and the average ratio of the fracture area to the total articular surface area was 17.84%. Besides, die-punch was seen in 27 cases and not in 21 cases. The average height of fractures was 21.33 ± 5.38 mm in group A1, 14.38 ± 9.01 mm in group B1, 18.30 ± 7.95 mm in group A2, 14.48 ± 5.37 mm in group B2, 26.26 ± 6.73 mm in group A3, and 12.77 ± 3.07 mm in group B3.

Conclusion

The height (H) of the posterior malleolar fractures is positively correlated with the fracture area (S) and the fracture area ratio (FAR). The posterior malleolar fractures with “die-punch” tend to have a greater average height than that without “die-punch.” In clinical work, orthopedic surgeons should not only pay attention to the size of the posterior malleolus fracture but also value its height, which hopefully could provide insight into the treatment and prognosis of PMF patients.

Operative Treatment of Posterior Malleolar Fractures

Fractures of the posterior malleolus can occur in conjunction with fibular and medial malleolar fractures or in isolation. The indications for fixation of the posterior malleolus remain controversial except for the fragment sizes. A number of different surgical approaches and techniques for internal fixation of posterior malleolar fractures have been reported. Newer techniques such as direct exposure and plating of the posterior malleolus are chosen more frequently than traditional techniques of indirect reduction and percutaneous screw fixation. These attributes help to minimize the occurrence of postoperative complications.

Direct medial approach in surgical fixation of fractures in the posterior aspect of the medial malleolus

Fractures in the posterior aspect of the medial malleolus form an important subset of ankle fractures and the indications for fixation include involvement of > 25% of the articular surface or an articular step off by > 2 mm. Several approaches have been described but there has been no recent study on the direct medial approach. Five fresh frozen cadaveric ankles were dissected using the direct medial approach. A longitudinal incision of 10 cm was centered directly over the medial malleolus and deepened straight down to the bone. The periosteum was identified over the distal tibia and careful subperiosteal dissection yielded access to the posterior aspect of the medial malleolus. We investigated the relationship of the neurovascular bundle to the incision by measuring the distance from the center of the medial malleolus to the closest aspect of the bundle. The mean distance from the center of the medial malleolus to the neurovascular bundle was only 2.64 cm (95% CI: 2.06 to 3.22 cm). We found that the neurovascular bundle could be avoided if a periosteal sheath was developed during the dissection and elevated off the posterior aspect of the medial malleolus. The direct medial approach can be performed safely by creating a periosteal sheath through subperiosteal dissection, and the distance of the neurovascular bundle from the incision allows for a good margin of safety during surgery. This approach can be extended proximally and distally and the medial malleolus can be fixed concurrently. Clin. Anat. 31:605-607, 2018. © 2017 Wiley Periodicals, Inc.

Posterior Malleolus Fractures

Posterior malleolus fractures vary in morphology. A computed tomography scan is imperative to evaluate fragment size, comminution, articular impaction, and syndesmotic disruption. Despite an increasing body of literature regarding posterior malleolus fractures, many questions remain unanswered. Although, historically, fragment size guided surgical fixation, it is becoming evident that fragment size should not solely dictate treatment. Surgical treatment should focus on restoring ankle joint structural integrity, which includes restoring articular congruity, correcting posterior talar translation, addressing articular impaction, removing osteochondral debris, and establishing syndesmotic stability.

Location of the sural nerve during posterolateral approach to the ankle

BACKGROUND

There is no consensus regarding the most appropriate surgical approach for the treatment of posterior malleolar fractures. The posterolateral approach facilitates more accurate reduction, but the sural nerve is potentially at risk during the approach. The location of this nerve in relation to this approach has not been clearly described in the literature.

MATERIALS AND METHODS

We performed cadaveric dissection of 12 legs using the posterolateral approach, a 10-cm incision midway between the tendo-achilles and the lateral malleolus, commencing at the tip of the lateral malleolus and extending proximally. The horizontal distances of the sural nerve and the short saphenous vein to the incision were measured at the proximal and distal ends and at the mid-point of the incision (positive towards the Achilles and negative towards the lateral malleolus).

RESULTS

In ten of the 12 cases, the sural nerve and short saphenous vein crossed the incision at an average of 56.7 mm and 61.0 mm along the incision, respectively. The median distances from the proximal end of the wound were -9.9 mm and -12.7 mm, 0.9 mm and -1.7 mm from the midpoint, and 6.3 mm and 7.7 mm from the distal end of the incision, respectively.

CONCLUSION

The sural nerve and saphenous vein are at risk of iatrogenic injury over the whole length of the incision for the posterolateral approach for posterior malleolar fractures.

CLINICAL RELEVANCE

When performing a posterolateral approach to the ankle, particular care should be taken at the midpoint of the incision.

Posterolateral approach to the displaced posterior malleolus: functional outcome and local morbidity

BACKGROUND

Stable anatomical reconstruction of the joint surface in ankle fractures is essential to successful recovery. However, the functional outcome of fractures involving the posterior tibial plafond is often poor. We describe the morbidity and functional outcome for plate fixation of the displaced posterior malleolus using a posterolateral approach.

MATERIALS AND METHODS

The posterolateral approach was used for osteosynthesis of the posterior malleolus in 45 consecutive patients (median age 54 years) with AO/Muller-classification type 44-A3 (n = 1), 44-B3 (n = 35), 44-C1 (n = 7), and 44-C2 (n = 2) ankle fractures. Thirty-three of the patients suffered complete fracture dislocation. Functional outcome at followup was measured using the modified Weber protocol and the standardized AAOS foot and ankle questionnaire. Radiological evaluation employed standardized anterior-posterior and lateral views.

RESULTS

The fragment comprised a median of 24% (range, 10% to 48%) of the articular surface. Postoperative soft tissue problems were encountered in five patients (11%), one of whom required revision surgery. Two patients (4%) developed Stage I complex regional pain syndrome. Clinical and radiological followup at 25 months disclosed no secondary displacement of the fixed fragment. The median foot and ankle score was 93 (range, 58 to 100), shoe comfort score was 77 (range, 0 to 100). A median score of 7 (range, 5 to 16) was documented using the modified Weber protocol.

CONCLUSION

The posterolateral approach allowed good exposure and stable fixation of a displaced posterior malleolar fragment with few local complications. The anatomical repositioning and stable fixation led to good functional and subjective outcome.

Posterior fracture dislocation of the ankle: technique and clinical experience using a posteromedial surgical approach

OBJECTIVE

The purpose of this study is to revisit the posteromedial surgical approach to the ankle and report the clinical outcomes of this technique in a cohort of 17 patients.

DESIGN

Retrospective.

SETTING

Level I trauma center.

PATIENTS

Seventeen patients between 1990 and 2006 were treated using a posteromedial surgical approach to the ankle. Thirteen presented with a posterior ankle fracture dislocation and 4 with an ankle fracture without dislocation producing a large posterior malleolar fragment. There were 6 males and 11 females, from 23 to 80 years of age (mean 45.2 years).

INTERVENTION

All but 2 patients underwent open reduction and internal fixation of the posterior malleolar fracture using a single posteromedial approach. A combined surgical approach (posteromedial and posterolateral) to the ankle was used in 2 cases.

MAIN OUTCOME MEASUREMENTS

The Foot and Ankle Outcomes Questionnaire was used to evaluate postoperative ankle pain, function, stiffness and swelling, and giving way. Posttraumatic osteoarthritis was assessed using an adapted 4-point radiographic grading system.

RESULTS

Follow-up data on 12 patients were obtained at a mean interval of 9.4 years. There were no wound complications. The average global foot and ankle score was 87 points (range 69-100). The degree of arthrosis was grades 0 in 3 ankles, I in 1 ankle, II in 5 ankles, and III in 3 ankles.

CONCLUSIONS

The posteromedial approach offers an effective technique for fracture reduction and buttress plate fixation of large posterior malleolar fragments. Good short- and mid-term clinical results should be expected.

Pathoanatomy of posterior malleolar fractures of the ankle

BACKGROUND

The functional outcome following ankle fractures that involve a posterior malleolar fragment is often not satisfactory, and treatment of this type of fracture remains controversial. Thorough knowledge of the pathologic anatomy of the posterior malleolar fracture is essential for planning appropriate treatment. Thus, we conducted a computed tomographic study to clarify the pathologic anatomy of the posterior malleolar fracture.

METHODS

Between 1999 and 2003, fifty-seven consecutive patients with a unilateral ankle fracture with one or more posterior fragments were managed at our hospital. We reviewed the patients' preoperative computed tomographic scans to determine (1) the ratio of the posterior fragment area to the total cross-sectional area of the tibial plafond and (2) the angle between the bimalleolar axis and the major fracture line of the posterior malleolus. Each fracture was categorized according to the location of the major fracture line on the computed tomographic image at the level of the tibial plafond.

RESULTS

The fifty-seven fractures were categorized into three types: (1) the posterolateral-oblique type (thirty-eight fractures; 67%), (2) the medial-extension type (eleven fractures; 19%), and (3) the small-shell type (eight fractures; 14%). Two of the eleven medial-extension fractures extended to the anterior part of the medial malleolus. A total of nine of the eleven medial-extension fractures actually consisted of two fragments [corrected] The conditions are not exclusive of one another; for example, in the case of one of the fractures exhibiting two fragments, the fracture also extended to the anterior part of the medial malleolus [corrected] The average area of the fragment comprised 11.7% of the cross-sectional area of the tibial plafond for posterolateral-oblique fractures and 29.8% for medial-extension fractures. In the cases of seven of the nine fractures that comprised >25% of the tibial plafond, the fracture line extended to the medial malleolus. The angles between the bimalleolar axis and the major fracture line of the posterior malleolus varied.

CONCLUSIONS

The fracture lines associated with posterior malleolar fractures appear to be highly variable. A large fragment extending to the medial malleolus existed in almost 20% of the posterior malleolar fractures in the current study, and some fragments involved almost the entire medial malleolus. Because of the great variation in fracture configurations, preoperative use of computed tomography may be justified. The information obtained from this study will be helpful for conducting basic research of this condition and for determining appropriate surgical approaches.

Posterolateral approach for open reduction and internal fixation of trimalleolar ankle fractures

Cell-cell and cell-matrix interactions are of critical importance in immunobiology. Leukocytes make extensive use of a specialized repertoire of receptors to mediate such processes. Among these receptors, integrins are known to be of crucial importance. This review deals with the central role of integrins and their counterreceptors during the establishment of leukocyte-endothelium contacts, interstitial migration, and final encounter with antigen-presenting cells to develop an appropriate immune response. Particularly, we have addressed the molecular events occurring during these sequential processes, leading to the dynamic subcellular redistribution of adhesion receptors and the reorganization of the actin cytoskeleton, which is reflected in changes in cytoarchitecture, including leukocyte polarization, endothelial docking structure formation, or immune synapse organization. The roles of signaling and structural actin cytoskeleton-associated proteins and organized membrane microdomains in the regulation of receptor adhesiveness are also discussed.