Congenital Cervical Scoliosis Treated with Concave Side Distraction with Three‐Dimensional Printed Titanium Cage

Study Design

Single-center, retrospective study.

Objective

Hemivertebra resection is the only treatment option for congenital cervical scoliosis (CCS). However, this procedure is complex and technically demanding. It often requires a considerably long operation, and there is substantial intraoperative bleeding. Therefore, we have attempted to treat CCS with a concave side distraction comprising a three-dimensional (3D) printed titanium cage. The purpose of this study is to evaluate the safety and efficacy of this technique for the treatment of patients with CCS.

Methods

A series of 22 patients with CCS who underwent a concave side distraction technique between 2019 and 2021 were retrospectively reviewed and analyzed. Radiological measurements included the Cobb angle of the distraction segments, the kyphosis angle, the range of movement, and the distraction correction angle. Student's t-test and Spearman correlation analysis were used for statistical analysis. p < 0.05 was considered statistically significant.

Results

The study included 12 males and 10 females whose ages ranged from 6 to 14 years old (9.8 ± 2.1 years old). Follow-up times ranged from 15 to 30 months (25.8 ± 3.6 months). Among 22 patients, two patients developed a postoperative C5 nerve root palsy and recovered after being treated with conservative treatment for 6 months. The duration of surgery ranged from 229 to 756 min (389 ± 112 min), and the estimated volume of blood loss ranged from 100 to 600mL (235 ± 121 mL). The coronal Cobb angle (p < 0.001), kyphosis angle (p < 0.05), and range of movement (p < 0.001) between the last follow-up and preoperative period were significantly different. A total of 28 segments were distracted, and the Cobb angle of the distraction segment ranged from 2.4 to 14.1° (8.5 ± 3.0°). There were six upper cervical spines (8.9 ± 1.9°) and 22 lower cervical spines (8.4 ± 3.2°) with no significant difference between them (p = 0.130). In addition, there was no correlation between the angle of the concave side distraction and patients’ age (r = 0.018, p = 0.315). The fusion was solid between the bone and the customized 3D-printed pore metal cage at the final follow-up.

Conclusion

The concave side distraction comprising a customized 3D-printed titanium cage implantation can provide satisfactory correction results and is a safe and reliable procedure for treating CCS.     

How accurate is computer-assisted mandible gunshot wound management by patient-specific distraction device? Preoperative planning versus postoperative outcomes

Gunshot wounds of the lower face are a challenge for the surgeon. Customized distraction osteogenesis (DO) is a well-established procedure for managing facial gunshot wounds. However, differences between the preoperative planning and postoperative outcomes are often noted. This multi-centre, retrospective study was performed to analyse the differences between the planning and outcomes for the lower third of the face, in patients undergoing the computer-assisted repair of mandible gunshot wounds using patient-specific distraction devices. Different planes and points were defined, and two distances (anteroposterior and intercondylar lengths) and an angle (inter-mandible body angle) were measured on the preoperative planning models and the postoperative models obtained from the computed tomography data. Twelve patient cases that met the study eligibility criteria were included. A significant difference between the planning and postoperative outcome was found for the anteroposterior length (6.6 mm shorter than the preoperative planning; P = 0.003). The differences in intercondylar length (P = 0.116) and inter-mandible body angle (P = 0.121) were not significant. This study revealed a difference between the planning and outcomes. Various factors such as scar tissue and muscle forces limit distraction and therefore lead to under-correction with insufficient projection.     

Helical distraction is superior to linear distraction in maxillary distraction osteogenesis: an in silico study

This in silico kinematic study was performed to evaluate the best attainable outcomes of maxillary distraction osteogenesis given the constraints of linear and helical motion. The study sample included the retrospective records of 30 patients with maxillary retrusion who had been treated with distraction or had been recommended this treatment. The primary outcomes were the errors of linear and helical distraction. The study measured two types of error: misalignment of key upper jaw landmarks and misalignment of the occlusion. Concerning the misalignment of key landmarks, the median misalignments resulting from helical distraction were minimal; the interquartile ranges were also minimal. The median misalignments and interquartile ranges that resulted from linear distraction were significantly larger. Regarding the occlusal misalignments, helical distraction produced minor occlusal misalignments, while linear distraction produced significantly larger errors. The results of this study confirmed that helical motion is the ideal motion for LeFort I distraction.     

Hybrid mandibular Bologna midline distractor in combination with surgically assisted rapid maxillary expansion for transverse facial expansion: clinical and cephalometric results

Transverse maxillomandibular hypoplasia can be treated with surgically assisted rapid maxillary expansion (SARME) in association with mandibular symphyseal distraction (MSD). This paper introduces a hybrid mandibular Bologna midline distractor (BMD); the effectiveness of the distractor in combination with SARME for the treatment of transverse skeletal deficiency was evaluated. This two-centre study included 10 patients with a transverse arch width deficit>7 mm and dental crowding, in both the maxilla and mandible, treated with SARME and MSD. The study design was partly retrospective (seven patients) and partly prospective (three patients). Frontal and lateral cephalometric analyses, as well as measurements on dental models, were performed at three different times: before treatment, after the distraction, and 6 months after postoperative orthodontic treatment. The cephalometric analyses and measurements on dental impressions confirmed a balanced and stable skeletal and dental mandibular expansion. An average symphyseal expansion of 7.8 mm was obtained, resolving dental crowding without dental extractions. In conclusion, mandibular expansion performed with the BMD in combination with SARME appears to be a viable surgical approach to transverse maxillomandibular hypoplasia. This technique allows the surgeon to obtain a balanced skeletal and dental expansion, with a low level of relapse.