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.

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.

Ankle fractures involving the posterior malleolus: patient characteristics and 7-year results in 100 cases.

INTRODUCTION: The presence of a posterior malleolar (PM) fragment has a negative prognostic impact in ankle fractures. The best treatment is still subject to debate. The aim of this study was to assess the medium-to-long-term clinical and functional outcome of ankle fractures with a PM fragment in a larger patient population. MATERIALS AND METHODS: One hundred patients (69 women, 31 men, average age 60 years) with ankle fractures including the PM were evaluated clinically and radiographically. Patients with Bartonícek-Rammelt type 3 and 4 fracture displayed a significant female preponderance. Fixation of the PM was performed in 63% and tailored to the individual fracture pattern. RESULTS: Internal fixation of the PM fragment was negatively correlated with the need for syndesmotic screw placement at the time of surgery (p = 0.010). At an average follow-up of 7.0 years, the mean Foot Function Index (FFI) was 16.5 (SD: 21.5), the Olerud Molander Ankle Score (OMAS) averaged 80.2 (SD: 24) and the American Orthopedic Foot & Ankle Society (AOFAS) ankle/hindfoot score averaged 87.5 (SD: 19.1). The maximum score of 100 was achieved by 44% of patients. The physical (PCS) and mental health component summary (MCS) scores of the SF-36 averaged 47.7 (SD: 12.51) and 50.5 (SD: 9.36), respectively. Range of motion was within 3.4 (SD: 6.63) degrees of the uninjured side. The size of the PM fragment had no prognostic value. There was a trend to lower outcome scores with slight anterior or posterior shift of the distal fibula within the tibial incisura. Patients who underwent primary internal fixation had significantly superior SF-36 MCS than patients who underwent staged internal fixation (p = 0.031). CONCLUSIONS: With an individualized treatment protocol, tailored to the CT-based assessment of PM fractures, favorable medium and long-term results can be expected.

Production of the Carboxylate Reductase from Nocardia otitidiscaviarum in a Soluble, Active Form for in†vitro Applications.

Accessing aldehydes from carboxylate moieties is often a challenging task. In this regard, carboxylate reductases (CARs) are promising catalysts provided by nature that are able to accomplish this task in just one step, avoiding over-reduction to the alcohol product. However, the heterologous expression of CARs can be quite difficult due to the excessive formation of insoluble protein, thus hindering further characterization and application of the enzyme. Here, the heterologous production of the carboxylate reductase from Nocardia otitidiscaviarum (NoCAR) was optimized by a combination of i) optimized cultivation conditions, ii) post-translational modification with a phosphopantetheinyl transferase and iii) selection of an appropriate expression strain. Especially, the selection of Escherichia coli tuner cells as host had a strong effect on the final 110-fold increase in the specific activity of NoCAR. This highly active NoCAR was used to reduce sodium benzoate to benzaldehyde, and it was successfully assembled with an in vitro regeneration of ATP and NADPH, being capable of reducing about 30 mM sodium benzoate with high selectivity in only 2 h of reaction.

[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.