This review research assesses the numerous 3D printing methods utilized in medical applications and the materials and design methods that are associated with the current and existing technology. The article thoroughly examines the advantages and disadvantages of various techniques and materials and the difficulties of applying 3D printing technology to the medical sector. Further research and development are required to overcome current challenges since the review highlights the importance of design strategies in achieving positive medical outcomes. Overall, the article provides a thorough overview of the state of 3D printing in medical applications today and its potential to revolutionize the industry.

Background and Objectives: This study retrospectively examined whether the incidence rates of adjacent vertebral fractures (AVFs) can be reduced through balloon kyphoplasty (BKP) for osteoporotic vertebral fractures (OVFs) in the early stages, when there is little vertebral height variation. Materials and Methods: A total of 95 patients (22 males, 73 females, mean age: 80.7 years) who had undergone BKP were divided into two groups: the Early group (underwent BKP within 2 weeks after injury, n = 62), and the Non-early group (underwent BKP > 2 weeks after injury, n = 33). The following data were analyzed: patient characteristics; fracture level; the presence of old vertebral fractures, posterior wall injury, and intravertebral cleft; duration of surgery; duration of hospitalization; cement volume; the occurrence of AVF; the timing of AVF occurrence; Numerical Rating Scale (NRS) scores at the preoperative, postoperative, and final follow-up assessments; posterior vertebral kyphosis angle of the affected vertebra on plain lateral X-ray; vertebral wedge ratio; local kyphotic angle; and changes in posterior vertebral kyphosis angle, vertebral wedge ratio, and local kyphotic angle between preoperative and postoperative assessments. The patients were divided based on the occurrence or non-occurrence of AVF after BKP: the Non-AVF group, in which AVF did not occur, and the AVF group, in which AVF occurred. Results: The incidence of AVF was 15.8% (15/95 patients), with a notably lower incidence rate in the Early group at 6.5% (4/62 patients) compared to the Non-early group at 33.3% (11/33 patients). NRS scores significantly improved in both groups at the postoperative assessment and final follow-up. The changes in posterior vertebral kyphosis angle and vertebral wedge ratio were significantly lower in the Early group. In the Non-AVF group, the time from injury to surgery was significantly shorter. Conclusions: The Early group had a significantly lower incidence of AVF. The time from injury to surgery was a risk factor for AVF occurrence, suggesting that early BKP is recommended.

Background and Objectives: The lateral approach is commonly used for anterior column reconstruction, indirect decompression, and fusion in patients with lumbar degenerative diseases and spinal deformities. However, intraoperative lumbar plexus injury may occur. This is a retrospective comparative study to investigate and compare neurological complications between the conventional lateral approach and a modified lateral approach at L4/5. Materials and Methods: Patients with a lumbar degenerative disease requiring single-level intervertebral fusion at L4/5 were included and categorized into group X and group A. Patients in group X underwent conventional extreme lateral interbody fusion, while those in group A underwent a modified surgical procedure that included splitting of the anterior third of the psoas muscle, which was dilated by the retractor on the anterior third of the intervertebral disc. The incidence of lumbar plexus injury, defined as a decrease of ≥1 grade on manual muscle testing of hip flexors and knee extensors and sensory impairment of the thigh for ≥3 weeks, on the approach side, was investigated. Results: Each group comprised 50 patients. No significant between-group differences in age, sex, body mass index, and approach side were observed. There was a significant between-group difference in intraoperative neuromonitoring stimulation value (13.1 ± 5.4 mA in group X vs. 18.5 ± 2.3 mA in group A, p < 0.001). The incidence of neurological complications was significantly higher in group X than in group A (10.0% vs. 0.0%, respectively, p < 0.05). Conclusions: In our modified procedure, the anterior third of the psoas muscle was entered and split, and the intervertebral disc could be reached without damaging the lumbar plexus. When performing lumbar surgery using the lateral approach, lumbar plexus injury can be avoided by following surgical indication criteria based on the location of the lumbar plexus with respect to the psoas muscle and changing the transpsoas approach to the intervertebral disc.

Background and Objectives: Although adjacent vertebral fractures (AVF) frequently occur after balloon kyphoplasty (BKP), their risk factors remain unclear. This retrospective study aimed to identify risk factors for AVF and evaluate the utility of Hounsfield unit (HU) values on preoperative vertebral computed tomography (CT) scans as predictors of its occurrence. Materials and Methods: We retrospectively evaluated 180 patients (46 male and 134 female individuals; mean age: 80.3 years; range: 60–94 years) who underwent BKP for osteoporotic vertebral fractures (OVFs) between 2021 and 2023 with at least 6 months of follow-up. The patients were categorized into the AVF (n = 31) and non-AVF (n = 149) groups. Analyzed variables included patient characteristics, fracture level, prior fractures, posterior wall injury, intravertebral cleft, vacuum phenomenon in adjacent intervertebral discs, injury-to-surgery interval, cement volume, kyphosis angles, wedge ratios, and HU values. HU values were measured at three levels on preoperative CT scans in the vertebrae above and below the treated segment. Cutoff HU values predictive of AVF were determined using receiver operating characteristic (ROC) curve analysis. Results: AVF incidence was 17.2% (31/180), with 71.0% occurring in the vertebrae above the treated level. HU values in all measured slices were significantly lower in the AVF group. The mean HU values in the upper vertebra were 61.1 ± 6.03 (AVF) and 84.7 ± 2.75 (non-AVF), and in the lower vertebra, 51.5 ± 8.44 and 81.0 ± 3.85, respectively. ROC analysis showed cutoff HU values of 79.3 and 61.0 for the upper and lower vertebrae, respectively. HU values were identified as independent AVF risk factors. Conclusions: Preoperative vertebral HU values are independent AVF predictors. Values below 79.3 in the upper or 61.0 in the lower vertebrae were linked to higher AVF risk, suggesting HU measurement is a simple, useful tool for preoperative risk assessment.

We report a case of scoliosis in a 12-year-old girl with Shprintzen–Goldberg syndrome. She was diagnosed with Shprintzen–Goldberg syndrome at birth. She was hospitalized for a surgical treatment because scoliosis gradually progressed. Preoperative X-ray confirmed 80° symptomatic scoliosis in T10–L5. Posterior correction and fusion were performed, and postoperative X-ray showed a correction to 43°in T10-L5. Limited subcutaneous tissues and fragile bones must be considered when selecting the appropriate surgical method. Accurate placement of a screw into thin pedicle is essential to obtain sufficient correction and fusion. The use of a navigation system is recommended.