|Year : 2022 | Volume
| Issue : 4 | Page : 480-484
Posterior malleolus fracture fixation in ankle injuries: A clinical study
Rutvik D Dave, Parag M Tank, Nimish B Patel, Poojan V Shah
Department of Orthopaedics, Smt. NHL Municipal Medical College, Ahmedabad- 380006, Gujarat, India
|Date of Submission||23-Aug-2022|
|Date of Acceptance||23-Sep-2022|
|Date of Web Publication||29-Dec-2022|
Dr. Poojan V Shah
Department of Orthopaedics, Smt. NHL Municipal Medical College, Ahmedabad- 380006, Gujarat
Source of Support: None, Conflict of Interest: None
Introduction: Posterior Malleolar fractures are relatively rare and a part of complex ankle injuries. Trimalleolar fractures affect the stability of the weight-bearing ankle joint. Management of posterior malleolar fractures is a challenge. Aims: This study aimed to examine the radiological and clinical outcomes of the management of posterior malleolar fractures in adults. Settings and Design: This is an original research retrospective studyMaterials and Methods: Eleven patients underwent fixation of ankle fractures with fixation of posterior malleolus as needed using screws or plates. Surgical outcomes were examined in follow-up with an average follow-up of 21 months using the American Orthopedic Foot and Ankle Score (AOFAS) score and with radiological correlation at each follow-up. Results: In our series, 27% of patients had 44B type injury and 73% of patients had 44C type injury as per AO/OTA classification. The average AOFAS score was 90.45 for the series and the score for patients treated with direct reduction of the fragment was better than for those treated with indirect reduction. The average score for patients managed with screws was better than for those treated with plates in our series. 82% of patients showed excellent to good outcomes with one patient having an infection and one patient having moderate to severe pain. Conclusion: Anatomical reduction of posterior malleolar fragment leads to better long-term functional outcomes and a stable ankle joint with early mobilization.
Keywords: Ankle injuries, posterior malleolar fractures, syndesmotic stability, trimalleolar fractures
|How to cite this article:|
Dave RD, Tank PM, Patel NB, Shah PV. Posterior malleolus fracture fixation in ankle injuries: A clinical study. MGM J Med Sci 2022;9:480-4
|How to cite this URL:|
Dave RD, Tank PM, Patel NB, Shah PV. Posterior malleolus fracture fixation in ankle injuries: A clinical study. MGM J Med Sci [serial online] 2022 [cited 2023 Jan 27];9:480-4. Available from: http://www.mgmjms.com/text.asp?2022/9/4/480/365970
| Introduction|| |
Posterior malleolar fractures are relatively rare injuries that affect the stability of the weight-bearing dome of the tibial plafond. Management of these injuries is controversial and has traditionally been defined by the size of the posterior malleolar fragment concerning the total area of the tibial plafond. However, a non-anatomic reduction of these fractures leads to worse surgical outcomes than non-operative management. This study aimed to examine the outcomes of management of posterior malleolar fractures in adults using clinical and radiological parameters.
| Materials and methods|| |
Eleven patients with ankle injuries were included in our study. Our sample size is limited to eleven patients because the fracture in itself is relatively rare. At our institution, all patients were attended by the same physician and resident orthopedic doctor at initial trauma and final surgery. Skeletally mature adult patients with a minimum age of 16 years to a maximum of 60 years were selected. All patients were thoroughly examined for axial skeleton and vital systems injuries and full ankle radiological surveys were undertaken. Preoperative hematological tests and anesthesia checks were embarked. Anesthesia and surgical consent were taken. All patients have undergone ethical consent form filling and research enrolment permissions.
All patients were given broad-spectrum intravenous antibiotics. AO/OTA and Haraguchi ankle fracture classifications were adopted for better fragment identification and to aid the management with a diligent plan. 12 months follow-up was carried out for all patients. AOFAS score was taken at the end of 3 months, 6 months, and 12 months.
- Skeletally mature patients
- AO/OTA 44B and 44C injuries.
- Haraguchi classification Type 1, 2, 3
- Closed injuries
- Ankle injuries with vascular jeopardy
- Associated hind and midfoot fractures
- Old neglected ankle injuries
- Neuroarthropathy and poliotic limbs
At the time of definitive surgery, patients were given spinal anesthesia and a tourniquet wrapped at thigh limbs was prepped and draped. 2 skin incisions were used in all patients. A skin incision was taken first at the lateral pillar of the ankle mortise. Length and angulations corrected keeping folded towel beneath the joint. Plantar flexion of the joint buttresses the Lefort Wagstaffe fragment of anteromedial fibular syndesmosis which then falls back and was clamped. Neutralization of one-third tubular or reconstruction 3.5 mm plate with or without interfragmentary screws was fixed. Stress views in dorsiflexion observed under image intensifier. Stability of posterior malleolus examined. If step off more than 2 mm then fixation is planned either with a direct or indirect approach.
Suprasyndesmotic fibular fractures were fixed with a single rush pin or square nail of 2.5–3.0 mm. Then in lateral decubitus, posterior malleolus fixation was done. Posterolateral fibula tendo-achilles interval selected just above calcaneal tuberosity. Peroneus and Flexor Hallucis Longus (FHL) deep surgical dissection was achieved. Direct posterior malleolus with posterolateral or posteromedial Volkmann fragment of Posterior Inferior Tibio Fibular Ligament (PITFL) avulsion tibial fragment was observed and stabilized with a dural probe or pointed ball tip probe and fixed with cannulated cancellous screw with or without washer. Large fragments with anterior subluxation of syndesmosis need a buttress 3.5 mm T plate with a horizontal limb at the verge of the lower posterior lip of the plafond. Stability and congruency checked. The wound closed in layers.
The patient was then placed supine on the operating table to address medial malleolus with a standard anteromedial incision. Care is taken to safeguard the saphenous neurovascular bundle. Fracture opened and debrided removing periosteum if any. Two cannulated 4.0 mm cancellous screws were fixed after precisely aligned joint line congruity. The wound was closed with skin stitches.
Patients with dorsiflexion ankle injuries require an anteromedial extensile approach to navigate anterior intraarticular impaction. Windows were made on either side of the neurovascular bundle. Buried articular disimpaction was achieved and fixed with either a T plate or two 3.5 mm reconstruction plates. This also engaged the reduced type of posterior malleolus.
| Results|| |
In our study, we had seven male and four female patients with a mean age of 38 years. Five patients had injuries in the right lower limb while six patients had injuries in the left lower limb. The predominant mechanism of injury was Road Traffic Accident (36%) followed by Fall from stairs (36%) and slip and fall on the road (27%) with equal incidence. 25% of patients had fractures associated with ankle dislocation (Two Posterior and One Lateral dislocation). The minimum follow-up period was 12 months with an average follow-up of 21 months duration. [Figure 1] & [Figure 2].
|Figure 1: Radiological outcome in case of a 23 year male with trimalleolar fracture treated with direct plating|
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|Figure 2: Radiological outcome in case of 18 year male with posterior malleolar fracture treated with AP screws|
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Classifying according to AO/OTA classification yielded 27% 44B types and 73% 44C types. [Table 1]. The classification of Posterior Malleolus by Haraguchi classification yielded 73% Haraguchi Type 1, 18% Type 2, and 9% Type 3.
Posterior Malleolus fixation was carried out as per the description above in 9 out of 11 cases (82%). Out of these four were Suprasyndesmotic fibula fractures, four were syndesmotic fibula fractures and one fracture had an intact fibula. Four fractures were fixed with direct reduction while five were fixed with indirect reduction. 25% of fractures treated with direct reduction were fixed using plate while 75% of them were fixed using screws. 60% of fractures treated with indirect reduction were fixed using plates while 40% were fixed using screws.
The average AOFAS score was 90.45 for the series. The average AOFAS for patients treated with direct reduction was 96.5 while for those treated with indirect reduction was 86.4 [Table 2]. The average AOFAS for patients managed with screws was 98.8 compared to 81 for patients managed with plates. 54.5% of patients showed excellent results, 27.5% showed good results, 9% showed fair and 9% showed poor results. 70% of patients showing excellent to good results had undergone posterior malleolus fixation. [Table 3].
Average dorsiflexion in the series was 16.6 degrees, plantar flexion 45.9 degrees, inversion 24.5 degrees, and eversion 17.3 degrees. All ankle joints were found to be stable by drawer test compared to the opposite side.
Complications included pain in six patients and infection in one patient in our series. Out of six patients complaining of pain, only one had severe pain enough to disrupt activities of daily living. The infection was superficial and it resolved with the administration of oral antibiotics and regular dressing of the wound.
| Discussion|| |
Selecting an appropriate treatment method for posterior malleolus fractures has been a question of debate among orthopedic surgeons. Fixation of posterior malleolus restores articular congruity and improves ankle stability. Nonanatomic restoration of joint surface predisposes to the development of osteoarthritis. Gardner et al. demonstrated that fixation of posterior malleolus restored 70% of syndesmotic stiffness while syndesmotic fixation restored only 40% of stiffness. This was due to the restoration of competence of the posterior inferior tibiofibular ligament.
This retrospective study shows that 50% of patients showed excellent results while 33.3% of patients showed good results. Varma et al showed a 76% rate of excellent to good results which is comparable with our study. Our series showed better results with the use of a screw for fixation of posterior malleolus vs plate in terms of Average AOFAS score. This is in contrast to Connor et al. who showed results better with plating vs screw. However, Connor et al. considered only Antero-Posterior screws while in our series a direct fixation of posterior malleolus with screws was also carried out when feasible. Karaca et al. showed an 83% rate of excellent to good results which is also comparable with our study. They however did not carry out a comparison between outcomes of plate vs screw as fixation methods.
The average dorsiflexion of our study was 16.63 degrees while plantar flexion was 45.9 degrees which are comparable to Karaca et al. and better than Varma et al, at an average 21 months follow-up. However, the difference with Varma et al. could be attributed to the smaller sample size in our study and a longer duration of follow-up affecting the average values.
The most common complication in our study was pain followed by infection. Little et al. analyzed complications of ankle fracture fixation and found the most common complication to be syndesmotic incongruence leading to pain followed by painful hardware and infection. Reducing the incidence of pain could be achieved by accurate reduction to minimize articular step-off, avoiding rotational malalignment, minimal soft tissue dissection, and early non-weight bearing joint mobilization.
In our study, 70% of patients showing excellent to good results had undergone posterior malleolus fixation while 30% had not undergone fixation. Tejwani et al noted that the AOFAS score in the group of patients with fixation of Posterior malleolus vs those patients who had not undergone fixation showed a significant difference at 1 Year. Verhage et al observed that concerning the size of posterior malleolus, the cut-off value above which posterior fragment should be fixed remains inconclusive. They also noted that increasing age, postoperative steps off, and high BMI are associated with worse functional outcomes. They suggested that the Postoperative step off, and not the size of the posterior malleolus fragment should be used as a guide to decide on the fixation of the posterior malleolus.
Long-term follow-up and meticulous surgical techniques are the strength of this study. A smaller sample size and retrospective non-randomized nature of the study is its limitations.
| Conclusion|| |
Posterior malleolus fractures are relatively rare injuries. With the advent of 3D reconstruction a few years, the anatomy is discernible and hence amenable to fixation in foot and ankle orthopedics.
The fixation of posterior malleolar fragments leads to better long-term functional outcomes and stable ankle joints. It also enables early mobilization of syndesmotic injuries due to a more stable construct and prevents the development of arthritis in long term. An anatomic reduction is key to a successful outcome. Further research in the form of a randomized controlled trial such as the ongoing POSTFIX trial is needed to conclude definitively on the need for posterior malleolar fixation.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest
The Institutional Ethics Committee has approved the study protocol vide letter no. NHLIRB/2022/August/17/01 dated November 17, 2022.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]