Do working length and proximal screw density influence the velocity of callus formation in distal tibia fractures treated with a medial bridge plate?

INTRODUCTION: Aim of our study was to evaluate the influence of working length and screw density on callus formation in distal tibial fractures fixed with a medial bridge plate. MATERIALS AND METHODS: 42 distal tibia fractures treated with a bridge plate were analyzed. Minimum follow-up was 12 months. mRUST score (modified Radiographic Union Scale for Tibial fractures) was used to assess callus formation. Working length and screw density were  measured from post-operative radiographs. RESULTS: 39 (92.9%) fractures healed uneventfully. 32 (76.19%) patients showed signs of early callus formation 3 months post-surgery. In these patients a lower screw density was used compared to patients who didn't show early callus (33.4 vs. 26.6; p = 0.04). No differences was noticed in working length. CONCLUSION: Bridge plate osteosynthesis is a good treatment option in distal tibia fractures. In our series increasing the working length was not associated with a faster callus formation in distal tibia fractures. Conversely, a lower screw density proximally to the fracture site was associated to a faster callus growth.

The risk of infection in open distal tibial fracture: the DANGER score.

INTRODUCTION: Open fractures of the distal tibia can be functionally devastating, and they remain one of the most challenging injuries treated by trauma surgeons usually burdened with a high rate of complications, including surgical site infections (SSI). Our aim is to analyze the most significant risk factors of SSI and propose a new scoring system-called the DANGER scale-potentially able to predict reliably and quantify the infection risk in distal tibia open fractures. METHODS: We identified six variables summarized in the acronym DANGER where D stands for Diabetes, A for Antibiotic, N for Nature of trauma (high- or low-energy trauma), G represents Grade of fracture following the AO/OTA classification, E indicates Exposure of the fracture according to the Gustilo-Anderson classification, and R represents Relative risk of patient, including use of tobacco, alcoholism, and psychiatric disorders. Therefore, total score ranged from 1 to 14, with a lower score indicating less risk to develop SSI. RESULTS: A total of 103 patients with open distal tibial fractures were enrolled, 12 patients (11.6%) developed SSI. Regarding DANGER score, a rating of 8.2 was calculated in SSI group and 4.8 in non-SSI group. Based on Fisher's test, diabetes (odds = 31.8 p < 0.05), grade of articular involvement (p < 0.05), severity of open fracture (p < 0.05), and dangerous behavior such as use of tobacco, alcoholism, and psychiatric disorders (p < 0.05) were significantly correlated with infection. Significant difference between total DANGER scores in SSI and non-SSI groups was found (p < 0.001). ROC curve was calculated founding a potential threshold of 7.5 (p < 0.001). CONCLUSION: Based on the above well-accepted risk factors, DANGER scale represents an advantageous and practical tool in order to readily estimate the risk of surgical site infection of open distal tibial fractures.

Does the anterior column realignment technique influences the stresses on posterior instrumentation in sagittal imbalance correction? A biomechanical, finite-element analysis of L5-S1 ALIF and L3-4 lateral ACR.

STUDY DESIGN: Biomechanical finite-element study. OBJECTIVE: To directly compare the biomechanical effects of two different techniques for sagittal plane correction of adult spine deformity based on the anterior longitudinal ligament (ALL) resection and use of hyperlordotic cages, namely, the anterior column realignment (ACR) in L3-4, and ALIF in L5-S1 in terms of primary stability and rod stresses using finite-element models. METHODS: A finite-element model of the thoracolumbar spine was used to perform the analysis. Starting from this "intact" model, three further models were constructed through the insertion of spinal instrumentation, i.e., pedicle screws, rods and cages: 1) posterior instrumentation between T9 and S1 (referred to as "T9-S1"); 2) posterior instrumentation T9-S1 + Hyperlordotic (26°) ALIF cage in L5-S1 ("ALIF"); 3) posterior instrumentation T9-S1 + Hyperlordotic (30°) ACR cage in L3-4 ("ACR"). These models were studied by simulations applying, alternately, a pure moment of 7.5 Nm between the three planes of motion (flexion, extension, lateral bending, and bilateral axial rotation), uniformly distributed over the upper surface of the T9 thoracic vertebra. A total of 24 simulations were performed (6 per models). RESULTS: All models presented a significant reduced ROM when compared to the intact model; the ROM reduction was higher both at L3-4 in the ACR model and at L5-S1 in the ALIF model. At L3-4, the ACR model had, in all cases, the lowest maximum values of Von Mises stresses on the rods, especially in flexion-extension. At L4-5, the ALIF model had the lowest stresses during flexion-extension and axial rotation, while the ACR model had the lowest stresses during lateral bending. At L5-S1, the ALIF model had, in all cases, the lowest stresses on the rods. CONCLUSIONS: This finite-element study showed how both ACR at L3-4 and ALIF-ACR at L5-S1 are effective in restoring lumbar lordosis (LL), stabilizing the spine and reducing stress on posterior rods at the index level when compared to a simple fixation model. Interestingly, ALIF-ACR reduces rod stress even at L4-5 in flexion-extension and axial rotation, possibly due to a better distribution of LL, especially on the lower arch, while ACR reduces the stress at L4-5 in lateral bending, possibly thanks to the larger footprint of the cage that increases the area of contact with the lateral side of the endplates.

Atypical APC-1 pelvic fracture presenting with pelvic instability: successful management with pubic symphysis fusion.

By definition, anteroposterior (AP) compression type 1 (APC-1) injury is a type of pelvic ring injury, which is widely acknowledged as 'stable'. Unstable forms of this injury are very rare and present a challenge for diagnosis and clinical management. Detailed herein is a man in his early 30s, referred to our institution with a 2-year history of pubic symphysis pain following a road traffic accident. Radiological investigation revealed an unstable APC-1 injury. This was subsequently managed with surgical reconstruction leading to the successful return of the patient to former function and recreational activities.