Minimally Invasive Technique in the Management of Tibial Pilon Fractures: New Approach and Promising Results

Background Comminuted tibial pilon fractures are induced by high-energy mechanisms and are often associated with soft tissue injuries. Their surgical approach is problematic due to postoperative complications. Minimally invasive management of these fractures has a considerable advantage in preserving the soft tissue and the fracture hematoma. Materials and Methods We conducted a retrospective study of a series of 28 cases treated at the Orthopedic and Traumatological Surgery Department of the CHU Ibn Sina in Rabat over a period of 3 years and 9 months, from January 2018 to September 2022. Results After a mean follow-up of 16 months, 26 cases had good clinical results according to the Biga SOFCOT criteria and 24 cases had good radiological results according to the Ovadia and Beals criteria. No cases of osteoarthritis were observed. No skin complications were reported. Conclusion This study highlights a new approach that deserves to be considered for this type of fracture as long as no consensus has been given.


Introduction
First described by Hulscher [1] in 1911, the tibial pilon represents the distal end of the tibia and extends from the tibiotalar joint up to 8 cm distal to this articular surface [2]. Tibial pilon fractures account for 5-7% of all tibial fractures [3][4][5] and most often occur as a result of high-energy trauma. Tese injuries most often produce signifcant comminution with fragment displacement and severe soft tissue trauma [6] in a young population with high functional demand. Te fbula is also fractured in 85% of high-energy tibial pilon fractures [7]. Tese fractures can also occur in an elderly population following low-energy trauma due to deterioration of bone quality. In this case, the soft tissues are compromised by comorbidities such as diabetes, arteriopathy, or medication.
While the surgical treatment must take into account the osseous component for stabilization, the importance of the soft tissues should not be neglected as they are subject to numerous skin and infectious complications [18]. Te soft tissues surrounding the distal tibia are often compromised, which is crucial for preoperative planning including the timing of the surgery [19].
Complications are common, involving infection, compartment syndrome, and osteoarthritis [20]. Conditioned media from human osteoarthritic synovium induce infammation in a synoviocyte cell line [21]. Te main objective of surgical treatment is to avoid skin and infectious complications by meticulous preoperative planning and to avoid the occurrence of ankle osteoarthritis, which could compromise the functional prognosis in a young population [22].
Since there are not enough studies on this new approach for the treatment of comminuted pilon fractures, we will try to highlight this technique based on a series of 28 cases and, through the results, to assess the risk of skin complications and infection, the occurrence of osteoarthritis, and the functional prognosis of the patients. Tis work could also serve as a pilot study before conducting comparative studies.

Study Group.
Te present work is a retrospective study of 28 cases of comminuted distal tibia fractures treated by minimally invasive plate osteosynthesis (MIPO) over a period from January 2018 to September 2022, collected in the Department of Orthopedic and Trauma Surgery at Ibn Sina University Hospital in Rabat.
Inclusion criteria were as follows: (1) age > 18 years; (2) patients admitted for tibial pilon fracture isolated or associated with other fractures; (3) patients treated for comminuted tibial pilon fracture; and (4) patients presenting with or without skin sufering.
We excluded from our study open fractures, patients who had received another therapeutic option, patients who were lost to follow-up, and incomplete records.
Gender, comorbidities, mechanism of injury, afected side, and laterality were not included in the selection criteria.
Te study of the fles was based on exploitation of the patients' medical fles, the operating reports, and the consultation registers. Data were entered on an Excel spreadsheet.
Skin lesions were evaluated according to the Tscherne classifcation. Te anatomopathological aspects of the fractures were studied on the basis of a descriptive radiological analysis using the AO/OTA classifcation system.
Te clinical assessment focused frst on the skin condition, then on the presence of pain, and the assessment of joint mobility. Radiographic control assessed the healing status of the bones.

Description of the Technique.
Te frst step in tibial reduction is fxation of the lateral malleolus. Depending on the condition of the skin around the fbula, the fbular fracture will be stabilized by percutaneous pinning (Figure 1) or by open reduction and internal fxation ( Figure 2). Tibial comminution limits the use of reduction forceps. After stabilization of the lateral malleolus, residual tibial displacement is observed. Tibial pilon fractures are most often displaced in varus and recurvatum. Te frst step is reduction of the articular surface, which must be anatomical. Ten, a transcalcaneal Steinmann pin is placed which allows traction and correction of the problems in the frontal plane. Te recurvatum is corrected with a towel roll placed under the leg in regard to the fracture site. Te incision is oblique to the medial malleolus and about 5 cm long. After preparing the tunnel with the rugine, the plate is inserted subcutaneously. Using the C-arm, the reduction and length of the plate are evaluated. Any displacement in the sagittal plane must be corrected. Te residual varus or valgus displacement will be eliminated by the efect of the plate. Te frst screw placed is the one closest to the fracture site on the distal fragment. Tis screw is bicortical and allows the entire distal fragment to be recalled and attached to the plate. Next, the proximal screws are used to stabilize the proximal fragment. Tey can be unicortical or bicortical if a locked plate is used. If a conventional plate is used, all screws must be bicortical. Finally, the screwing of the other holes will be completed.

Postoperative Management.
All our patients benefted from medical treatment for pain, thromboprophylaxis for 14 days and antibiotic prophylaxis for 48 hours. Immobilization was systematically performed for 6 weeks.
Te day after surgery, a lymphatic drainage massage is started with knee mobilization and isometric contractions of the leg muscles.
Two orthogonal radiographic views were performed immediately after surgery (Figures 1 and 2) and at each follow-up.

Results
Te average age of our patients was 41.5 years (between 28 and 50 years), with a sex ratio of 1.3 (16 males and 12 females). Te trauma was of high energy in all our patients. Te fracture occurred after a road trafc accident in 20 cases and due to a fall from great height in 8 cases. Te right side was afected in 17 cases and the left in 11 cases. Te patients presented to the emergency room on average within two hours of the trauma and were operated on within 4 to 24 hours of the trauma.
Te Tscherne classifcation was used to evaluate skin injuries. 6 cases had a grade I clinical appearance; 18 cases had grade II skin contusion; only two cases presented with simple ankle edema (Table 1). A complete radiological workup was performed, including standard radiographs with two views (anteroposterior and lateral), with additional CT scans. Te Ruedi and Allgower classifcation was not applied since it does not consider the metaphyseal segment of the tibia nor the malleolar component. Our patients were classifed according to the AO model. 7 patients had a type A2 lesion; 11 cases had a type A3 lesion; 6 patients had a type C2 lesion; and 4 patients had a type C3 lesion. Te fracture of the lateral malleolus was present in all patients ( Table 2). No dislocation was noted. Te neurovascular system was intact in all our patients.
Te average follow-up was 16 months. Monthly control was recommended for the frst 6 months, followed by longterm control every 6 months. Clinical evaluation was based on the Biga SOFCOT criteria [23] which take into consideration pain, walk, mobility, and edema (Table 3). Radiological control assessed the quality of reduction, consolidation, joint congruence, and the presence of signs of osteoarthritis. Te results were evaluated according to the Ovadia and Beals criteria [24] (Table 4). Bone healing was obtained on average after 5 months of surgery. No skin complications were noted; joint mobility was symmetrical to the healthy side ( Figure 3); intermittent pain was reported in 2 cases. No cases of arthritis were observed.

Discussion
Tibial pilon fractures represent a surgical challenge, and their management remains difcult because they are intraarticular lesions associated with various degrees of soft tissue injury. Te mechanism is variable and most often violent, resulting in signifcant soft tissue damage and highly comminuted displaced fractures [25]. Tere are several classifcation systems, the most inclusive of which is the AO/ OTA classifcation of tibial pilon fractures: extra-articular (43-A); partial articular (43-B); and complete articular (43-C). Tese types are subdivided according to comminution. Soft tissue injuries are classifed according to the Tscherne classifcation.
Te goal of surgical treatment is restoration of limb length and alignment, as well as anatomic reduction of the articular surface [2]. Although several techniques have been described for the management of pilon fractures, few have addressed comminuted distal tibial fractures. Minimally invasive osteosynthesis was designed to minimize the risk of infection and pseudarthrosis. It also allows the preservation of the biological arsenal during bone healing by conserving the fracture hematoma and avoiding periosteal stripping [26]. Kim et al. [27] studied type C fractures treated with MIPO with satisfactory results and signifcantly fewer skin complications. Baumgaertel et al. [28] reported callus formation in the frst weeks following biological fxation. Te onset of bone healing was observed after 5 to 6 weeks following open anatomical reduction. Davidovitch et al. [29] conducted a comparative study between 2-stage internal osteosynthesis and external fxation. Tere was no signifcant diference between both groups in regaining joint range of motion; postoperative skin complications were signifcantly less for ORIF. A study was conducted by Biz et al. [30] evaluating the medium-and long-term results in 94 patients with 43-B and 43-C fractures using all three techniques: ORIF, MIPO, and external fxation. Te radiographic and clinical results when the MIPO technique was used were slightly better than those of ORIF and much better than those of external fxation.
In our group of patients, 28 cases of comminuted tibial pilon fractures were operated on using the MIPO technique.

Conclusion
In conclusion, based on the results of our study, the MIPO technique should be of considerable interest in the management of tibial pilon fractures, particularly when the soft tissue is compromised and exposure of the fracture site would be fatal. Tis technique, through very short incisions, provides soft tissue protection. Tis approach avoids manipulation and devascularization of the fragments and preserves the fractured hematoma, thus allowing for adequate biological consolidation.

Data Availability
Te datasets used and analysed during the study are available from the corresponding author.

Consent
Written consent was obtained from the patients.

Conflicts of Interest
Te authors declare that there are no conficts of interest.