Mohammed El-Gebiely, MD Abstract no. (45364) Minimally Invasive Percutaneous Plate Osteosyntheseis for Lateral Malleolus Fractures Radwan G. Metwaly, MD Zeiad M. Zakaria, MD Mohammed El-Gebiely, MD Sherif Moustafa, MD Ain-Shams University, Cairo, Egypt

The authors declare that they have no conflict of interest

Introduction Lateral malleolar fractures may be a part of pott’s ankle fracture or pilon fracture. Soft tissue status may alter the management of such a fracture. Staged protocol have been described to optimize soft tissue condition and facilitate planned internal fixation either using a skeletal traction, external fixator or by reduction and fixation of lateral malleolus Pilon fracture 1st stage

Introduction Open reduction & internal fixation is the gold standard for lateral malleolar fractures Skin condition, planned other approaches and comorbidities might impede open reduction technique MIPPO for lateral malleolus may be a suitable solution for ankle fractures with skin problems and as astaged protocol in pilon fractures

Materials and methods Prospective case series Study Design From May 2012 to May 2014 Study Duration Fifty-six No. of patients Ankle fracture: twenty-six (46.42%) Pilon fracture: thirty patients (53.58%) Type of fracture Weber (C): 8 (30%) Weber (B): 18 (70%) 18 (60%) Weber (B): 12(40%) Lateral malleolar 5 uncontrolled DM 8 with skin bullae Grade (III): 5 Grade (II): 19 Grade (I): 6 Skin condition (Tscherene class.) Restore ankle mortise Two incisions proximal and distal each of 2 cm Check reduction of length, alignment and rotation under image intensifier Approach Locked 3.5mm plates with at least two screws proximal and two distal screws in pilon fractures One-third tubular plate in cases of ankle fracture In cases of ankle fracture with weber type (B) lag screw was added Fixation

Results All patients had closed soft tissue injury. Patients admission: within 2 days of injury (from two hours to 8 days following trauma) The average time for fixation: within ten hours since hospital admission (six to twenty-four hours) Duration of procedure: fifty minutes (twenty minutes to eighty minutes) Average union rate: within 6 weeks (6 - 10 weeks) Ankle function: all patients had good to excellent according to ankle and foot scoring system Complications: two patients with superficial wound infection healed with antibiotics (3.5%) No superficial peroneal nerve injury was documented One patient of the pilon group with varus loss of reduction less than 5° (3.3%)

Post-operative X-rays and CT scan (pilon fracture with staged protocol)

Steps and Pre and post operative X-rays Weber (B) fracture

Discussion Soft tissue status is one of the determining factors that may alter fracture management in the ankle region because of paucity of the covering soft tissue envelope and blood supply A staged protocol have been suggested for such a fracture when a temporary external fixation for the tibia is done till the soft tissue condition is allowing for further open approaches Another technique for such a staged protocol could be achieved by fixing the fibular fracture The biomechanical value of lateral malleolus is in sharing to create the congruent articular surface of the ankle mortise forming the lateral articular surface of the ankle joint. Preserving the normal relationship of the lateral malleolus within the ankle mortise guarantee the symmetrical distribution of contact stresses along the articular surfaces Fixation of the distal fibular fractures through MIPPO technique (the internal fixator) have the advantages of fixed angle device acting as stage one of the staged protocol for the tibial plafond fracture without the risk of pin tract infection and as a definitive fixation method for the fibular fracture Superficial peroneal nerve injury is at risk, that had been encountered with lateral malleolus fracture in up to 15% of cases and the risk is significantly increased with the direct lateral approach to the fibula, this is because of the different track of the terminal part of the nerve that pierce the leg fascia at different levels to become subcutaneous as described by Blair. Type B is at most risk to be injuried, MIPPO is a safe technique to avoid its injury

Conclusion MIPPO for lateral malleolus is an effective and safe technique provided that ankle mortise congruity is obtained.