Single-Window Versus Two-Window Posterolateral Approach for Malleolar Fractures

Ankle fractures involving the posterior malleolus are complex injuries that require anatomical reduction and stable fixation to prevent post-traumatic osteoarthritis. The posterolateral surgical approach allows direct visualization and fixation of both the posterior and lateral malleoli through a single incision. However, the optimal deep dissection technique and fibular plating strategy remain controversial.

The traditional two-window technique involves creating one interval medial to the peroneal tendons for posterior malleolus fixation, and a second interval lateral to the peroneal tendons to apply a standard lateral anatomic plate to the fibula. Alternatively, the single-window technique utilizes only the interval medial to the peroneal tendons to fix both malleoli, utilizing a posterior antiglide plate for the fibula.

This prospective study aims to compare the clinical and functional outcomes of these two techniques. The primary hypothesis is that the single-window approach with posterior antiglide plating will significantly minimize soft-tissue stripping, thereby reducing the incidence of early wound complications and late implant-related irritation, while providing excellent biomechanical stability against external rotation forces.

Patients with acute, closed ankle fractures involving both the distal fibula and the posterior malleolus will be included. To avoid confounding variables and methodological bias, patients demonstrating persistent syndesmotic instability that requires additional trans-syndesmotic fixation (screws or buttons) will be excluded from the study, as the single-window approach inherently restricts direct lateral access for such procedures. Clinical evaluations will include the assessment of early wound complications (dehiscence, necrosis, infection) within the first 3 months, as well as functional outcomes using the American Orthopaedic Foot and Ankle Society (AOFAS) score, range of motion, and Visual Analog Scale (VAS) for pain at 6 and 12 months postoperatively.

Inclusion criteria

• Patients aged between 18 and 65 years.
• Diagnosis of an acute, closed, unstable rotational ankle fracture with concomitant involvement of the posterior malleolus and lateral malleolus (trimalleolar or bimalleolar equivalent fractures).
• Fracture morphology explicitly indicating surgical reduction and internal fixation via a posterolateral approach (e.g., Bartonicek Type II, III, or IV).
• Ability to provide informed consent and willingness to comply with the 12-month postoperative rehabilitation and follow-up protocol.

Exclusion criteria

• Open fractures, severe tibial pilon variants, or fractures with intra-articular comminution extending beyond the posterior malleolus.
• Persistent Syndesmotic Instability: Patients demonstrating persistent distal tibiofibular syndesmotic instability (confirmed by intraoperative hook test) after the fixation of the posterior and lateral malleoli, which inherently requires additional trans-syndesmotic fixation (e.g., syndesmotic screws or suture-button devices). This exclusion is strictly applied to eliminate methodological bias, as the experimental single-window approach intentionally restricts direct lateral access for trans-syndesmotic interventions.
• Delayed surgical intervention exceeding 7 days from the initial trauma, leading to organized hematoma or compromised soft-tissue envelopes.
• Pre-existing conditions detrimental to soft-tissue healing and functional assessment, including severe peripheral arterial disease, uncontrolled diabetes mellitus with neuropathy, or severe ipsilateral ankle osteoarthritis.
• Previous history of ipsilateral ankle fractures or surgeries.