Ankle fractures involving the anterolateral distal tibia: medium-term clinical results of 50 cases.

PURPOSE: The anterolateral distal tibial rim (anterior malleolus, AM) is frequently fractured in malleolar fractures. The aim of this study was to evaluate the medium-term outcomes of malleolar fractures involving the AM. METHODS: Among 100 patients with AM fractures that were treated over a 10-year period, 50 patients were available for follow-up. Outcome was assessed with the Olerud Molander Ankle Score (OMAS), the Foot Function Index (FFI-D), the EuroQol (EQ)-5D-5L Index, the EQ-VAS and the AOFAS Ankle-Hindfoot Score. Type 1 AM fractures (bony syndesmotic avulsions) were fixed surgically with either a suture anchor or a transosseous suture in 11 of 22 cases (50%). Among type 2 AM fractures (with incisura and joint involvement), 68% were treated surgically with screw fixation. All three type 3 AM fractures (anterolateral tibial plafond impaction) were treated surgically with either screw or plate fixation. RESULTS: At follow-up, the median OMAS was 75, the FFI-D 19, the EQ-5D-5L-Index 0.88, the EQ-VAS 70, and the AOFAS score 93. Assuming that the fracture severity increases from Supination-External Rotation to Pronation-External Rotation and Pronation-Abduction injuries, the AOFAS score (p < 0.001), OMAS score (p = 0.009), and FFI-D (p = 0.041) all showed a significantly inferior clinical outcome with increasing fracture severity. Patients who required surgical revision (n = 5) showed a significantly inferior outcome with the OMAS (p = 0.019). CONCLUSIONS: A differentiated treatment protocol tailored to dislocation, size, incisura involvement and joint impaction leads to favourable outcomes in complex malleolar fractures involving the AM. More data are needed on the outcome of AM fractures that are still commonly underestimated and overlooked.

Complications following surgical treatment of posterior malleolar fractures: an analysis of 300 cases.

AIMS: The treatment of ankle fractures and fracture-dislocations involving the posterior malleolus (PM) has undergone considerable changes over the past decade. The aim of our study was to identify risk factors related to the occurrence of complications in surgically treated ankle fractures with PM involvement. PATIENTS AND METHODS: We retrospectively analyzed 300 patients at a mean age of 57 years with 300 ankle fractures involving the PM treated surgically at our institution over a 12-year period. The following relevant comorbidities were noted: arterial hypertension (43.7%; n = 131), diabetes mellitus (DM) (14.0%; n = 42), thereof insulin-dependent (3.7%; n = 11), peripheral vascular disease (0.7%; n = 2), osteoporosis (12.0%; n = 36), dementia (1.0%; n = 3), and rheumatoid arthritis (2.0%; n = 6). Furthermore, nicotine consumption was recorded in 7.3% (n = 22) and alcohol abuse in 4.0% (n = 12). RESULTS: Complications occurred in 41 patients (13.7%). A total of 20 (6.7%) revision surgeries had to be performed. Patients with DM (p < 0.001), peripheral vascular disease (p = 0.003) and arterial hypertension (p = 0.001) had a significantly increased risk of delayed wound healing. Alcohol abuse was associated with a significantly higher overall complication rate (OR 3.40; 95% CI 0.97-11.83; p = 0.043), increased rates of wound healing problems (OR 11.32; 95% CI 1.94-65.60; p = 0.001) and malalignment requiring revision (p = 0.033). The presence of an open fracture was associated with an increased rate of infection and wound necrosis requiring revision (OR 14.25; 95% CI 2.39-84.84; p < 0.001). Multivariate analysis identified BMI (p = 0.028), insulin-dependent DM (p = 0.003), and staged fixation (p = 0.043) as independent risk factors for delayed wound healing. Compared to the traditional lateral approach, using the posterolateral approach for fibular fixation did not lead to increased complication rates. CONCLUSIONS: Significant risk factors for the occurrence of complications following PM fracture treatment were identified. An individually tailored treatment regimen that incorporates all risk factors is important for a good outcome.

Pathoanatomy of the Anterolateral Tibial Fragment in Ankle Fractures.

BACKGROUND: The anterior distal tibial tubercle provides attachment to the anterior tibiofibular syndesmosis. It may be considered a fourth, or anterior, malleolus (AM). Fractures of the AM may extend into the tibial incisura and tibial plafond. The purpose of this study was to analyze the pathoanatomy of AM fractures and associated ankle injuries. METHODS: One hundred and forty patients (median age, 61.0 years) with a total of 140 acute malleolar fractures (OTA/AO 44) involving the anterolateral distal tibial rim were analyzed with computed tomography (CT) imaging. All components of the malleolar fractures were analyzed and classified. Fracture patterns were compared with those of all patients with malleolar fractures treated during the same 9-year period. Patients with fractures of the tibial pilon (OTA/AO 43) and patients <18 years of age were excluded. RESULTS: Of the 140 AM fractures, 52.9% were classified as type 1 (extra-articular avulsion); 35.7%, type 2 (incisura and plafond involvement); and 11.4%, type 3 (impaction of the anterolateral plafond). The fibula was fractured in 87.1%; the medial malleolus, in 66.4%; and the posterior malleolus, in 68.6%. An isolated AM fracture was seen in 4.3%. The size of the AM fractures correlated negatively with that of the posterior malleolar fractures. The proportion of pronation-abduction fractures increased and the proportion of supination-external rotation fractures decreased as the type of AM fracture increased. A fracture involving the AM occurred in 12.6% of all ankle fractures and occurred significantly more frequently in pronation-type injuries and elderly patients. No supination-adduction fractures with AM involvement were seen. The intraclass correlation coefficient for the proposed classification of the AM fractures was 0.961 (95% confidence interval [CI] = 0.933 to 0.980) for interobserver agreement and 0.941 (95% CI = 0.867 to 0.974) for intraobserver agreement. CONCLUSIONS: Knowledge of the 3D pathoanatomy of AM fractures and associated malleolar fractures may help with surgical decision-making and planning. CT imaging should be employed generously in the diagnosis of complex ankle fractures, in particular with pronation-type injuries. CLINICAL RELEVANCE: Depending on the individual 3D fracture pattern, fixation of displaced anterolateral distal tibial fragments potentially contributes to the restoration of joint congruity, tibiofibular alignment, and syndesmotic stability in complex malleolar fractures.

Fixation of anterolateral distal tibial fractures: the anterior malleolus.

OBJECTIVE: The anterior tibial rim with the anterolateral tibial tubercle provides attachment to the anterior tibiofibular syndesmosis. It may be considered an anterior or "fourth" malleolus. Fixation of a displaced anterior tibial fragment in the treatment of malleolar fractures aims at providing a bone-to-bone fixation of the anterior tibiofibular ligament and restoring the integrity of the tibial incisura. INDICATIONS: Displaced intra-articular fragments of the anterior tibia; fractures involving the tibial incisura; fractures with intercalary fragments; impaction of the anterior tibial plafond; syndesmotic avulsions producing instability or preventing reduction of the distal fibula into the tibial incisura. CONTRAINDICATIONS: Critical local soft tissues preventing an anterolateral approach; missing consent to surgery by the patient; overall critical general condition preventing surgery to the extremities. SURGICAL TECHNIQUE: Anterolateral approach over the tibial tubercle. Identification and mobilization of the anterior tibial fragment without dissecting the anterior syndesmosis. Reduction of the anterior tibial fragment with a pointed reduction clamp. Fixation of extra-articular avulsion fractures (type 1) with suture anchor. Screw fixation of larger fragments involving the joint surface and incisura (type 2). Disimpaction, realignment of the joint surface, bone grafting as needed and plate fixation of impaction fractures of the anterolateral tibial plafond (type 3). POSTOPERATIVE MANAGEMENT: Mobilization with partial weight bearing (15-20 kg) in a special boot (ankle foot orthosis) or cast for 6-8 weeks depending on the overall malleolar fracture pattern, bone quality and patient compliance. RESULTS: Few studies report the results of anterior tibial fractures in adults. Failure to fix displaced fragments frequently leads to nonunions. Overlooked Chaput fractures have been reported to result in malpositioning of the distal fibula in the tibial incisura leading to incongruity of the ankle mortise requiring revision surgery. Secondary avascular necrosis of the anterolateral tibial plafond may develop after joint impaction.

[Fractures of the anterolateral tibial rim : The fourth malleolus]. / Frakturen der lateralen Tibiavorderkante : Der vierte Knöchel.

The anterolateral tibial rim with the anterior tibial tubercle (Tubercule de Tillaux-Chaput) serves as an insertion site of the anterior inferior tibiofibular ligament (AITFL). It can also be termed the anterior malleolus or fourth malleolus. Fractures of the anterolateral tibial rim typically result from an external rotation or abduction mechanism of the talus within the ankle mortise. They are frequently overlooked in plain radiographs. Computed tomography (CT) is needed for an exact visualization of the fracture anatomy and treatment planning. A total of three main types can be differentiated: (1) extra-articular avulsion fracture of the AITFL, (2) fracture of the anterolateral distal tibia with involvement of the joint and tibial incisura and (3) impaction fracture of the anterolateral tibial plafond. Surgical fixation of displaced anterolateral distal tibial fractures aims at bone-to-bone stabilization of the anterior syndesmosis, restoration of the tibial incisura for the distal fibula and joint surface. Displaced extra-articular avulsion fractures (type 1) are fixed with a suture anchor or transosseal suture. Larger fragments involving the tibial incisura and plafond (type 2) are mostly fixed with screws. Impression fractures of the anterolateral tibial plafond (type 3) necessitate elevation with restoration of the joint surface, bone grafting of the impaction zone as needed and anterior buttress plating. Only a few studies have reported the treatment results of anterolateral tibial rim fractures in adults. Conservative treatment of dislocated fragments reportedly leads to non-union and malposition of the distal fibula with incongruence of the ankle mortise requiring revision. Impaction fractures (type 3) can lead to secondary avascular necrosis of the anterolateral tibial plafond.

Surgical Fixation of Quadrimalleolar Fractures of the Ankle.

SUMMARY: We present a technique of fixation of trimalleolar fractures with additional fracture of the anterior tibial tubercle ("quadrimalleolar") or anterior fibular rim ("quadrimalleolar equivalent"). Twenty-four patients with a mean age of 60 years were treated with open reduction and internal fixation of all 4 malleoli. There were 17 quadrimalleolar and 6 quadrimalleolar equivalent fractures. One patient had both anterior tibial and fibular avulsion fracture in addition to a trimalleolar ankle fracture. Surgical approaches and internal fixation were tailored individually. Twenty patients were operated in the prone position with direct fixation of the posterior malleolus and 4 patients in the supine position with anterior to posterior screw fixation of the posterior malleolus. After fixation of al 4 malleoli, only 1 patient (4%) required a syndesmotic screw for residual syndesmotic instability on intraoperative testing. There were no infections and no wound healing problems. All patients went on to solid union. Nineteen patients (79%) were followed for a mean of 77 months (range, 15-156 months). The Foot Function Index averaged 15 (range, 50 to 0), the Olerud and Molander Score averaged 79 (range, 45-100), and the American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Scale averaged 87 (range, 39-100). Fixation of the anterior and posterior tibial fragments increases syndesmotic stability by providing a bone-to-bone fixation. Anatomic reduction of the anterior and posterior tibial rim restores the physiological shape of the tibial incisura and therefore facilitates fibular reduction.