The effect of the size of pedicle screw on the long-term radiological and clinical results of short-segment posterior instrumentation in the management of thoracolumbar vertebral fractures.

OBJECTIVE: It was aimed at evaluating the effect of the size of the pedicle screw placed on the fractured vertebra on the long-term radiological and clinical results of short-segment posterior instrumentation applied in the surgical treatment of thoracolumbar vertebral fractures. METHODS: This retrospective study included 36 patients who underwent short-segment posterior instrumentation surgery for a single-level thoracolumbar (T11-L2) fracture between January 2015 and March 2021. The patients included in the study were divided into 2 groups according to the size of the pedicle screw placed in the fractured vertebra (group A: intermediate screw 4.5 mm, ≤35 mm+less than 50% of the vertebral corpus length, m/f: 13/4, n: 17, age: 36.5; group B: intermediate screw 5.5 mm, ≥40 mm+more than 70% of the vertebral corpus length, m/f: 11/8, n: 19, age: 42.6). All patients were periodically evaluated clinically and radiologically. Vertebral compression angle (VCA), anterior and posterior vertebral body height (ABH-PBH), intraoperative parameters (instrumentation time and intraoperative fluoroscopy number), and complications were compared between the 2 groups. RESULTS: Both groups were comparable with respect to age, sex, level of injury, AO classification, mechanism of injury, and American Spinal Cord Injury Association impairment scale. Restoration of VCA and vertebral corpus heights was achieved sufficiently in both groups after operation (P < .0001). There was no significant difference between the 2 groups in terms of early postoperative VCA, VCA measured at final follow-up, or loss of correction in VCA. At the last follow-up, PBH was statistically significantly better preserved in group B (P=.0424). There was no difference between the 2 groups in terms of operation time and the number of intraoperative fluoroscopies. Implant failure was observed in 1 patient in group A. CONCLUSION: This study has revealed that using a long, thick pedicle screw placed in the fractured vertebra can better preserve the PBH at the final follow-up. No correlation was found between the size of the intermediate screw and the preservation of the correction in the postoperative vertebral heights and VCA during the follow-up. LEVEL OF EVIDENCE: Level III, Therapeutic Study.

Should the level of the posterior instrumentation combined with the intermediate screw be a short segment or a long segment in thoracolumbar fractures with fusion to the fractured segment?

PURPOSE: It was aimed to compare the results of long segment posterior instrumentation with intermediate pedicular screw + fusion at the level of the fractured segment including one vertebra above and one below the fractured vertebra (LSPI) and short segment posterior instrumentation with intermediate pedicular screw + fusion at the level of the fractured segment including one vertebra above and one below the fractured vertebra (SSPI) in the surgical treatment of thoracolumbar vertebral fractures. METHODS: Ninety patients with thoracolumbar vertebral (T11-L2) fractures operated between March 2015 and February 2022 were included in this retrospective study. The patients were divided into two groups as those who underwent LSPI (n, 54; age, 40.3) and those who underwent SSPI (n, 36; age, 39.7). Radiological evaluations like vertebral compression angle (VCA), vertebral corpus heights (VCH), intraoperative parameters, and complications were compared between the groups. RESULTS: Correction in early postoperative VCA was statistically significantly better in LSPI (p = 0.003). At 1-year follow-up, postoperative VCA correction was significantly more successful in LSPI (p = 0.001). There was no difference between the two groups in terms of correction loss in VCA measured at 1-year follow-up. There was no statistically significant difference between the two groups in terms of postoperative VCH, VCH at 1-year follow-up, and correction loss in VCH. CONCLUSION: LSPI provides better postoperative kyphosis correction of the fractured vertebra than SSPI. Regarding the segment level of posterior instrumentation, there was no difference between the two groups in terms of the loss of achieved correction of VCA, ABH, and PBH at 1-year follow-up. Operating a thoracolumbar fracture with LSPI will lengthen the operation and increase the number of intraoperative fluoroscopies compared to SSPI.

Impact of surgery simulation using a 3-dimensional printed model on outcomes of hallux valgus surgery with distal chevron osteotomy: A randomized controlled trial.

OBJECTIVE:  This study aimed to compare the outcomes of traditional surgery (TS) with those of a 3-dimensional model-assisted surgery (3DS) in hallux valgus (HV) surgery with distal chevron osteotomy. METHODS: This randomized controlled trial study included 30 patients randomly grouped as TS and 3DS. In the 3DS group, the surgery was simulated on the 3D model before surgery, and that simulation was used as a guide during surgery. Various parameters, such as angles of the HV, intermetatarsal (IM), and distal metatarsal articular, were measured pre-surgery and during the final follow-up. The extent of lateralization of the first metatarsal (FM) head and plantar displacement of the FM head were assessed. Metrics like the duration of the osteotomy+lateralization+K wire fixation, tourniquet time, and fluoroscopy usage were recorded. All assessments were conducted independently and blindly. Patients remained unaware of their group allocation and the randomization procedure. RESULTS: Both groups showed no statistical differences in gender, operated side, age, or follow-up duration. For instance, in the 3DS group (n=15, age: 44.6 ± 9.6 years, male/female: 14/1, side right/left: 11/4, follow-up duration: 29.4 ± 8.7 months) and TS group (n=15, age: 44.8 ± 9.6 years, male/female: 13/2, side right/left: 10/5, follow-up duration: 28.8 ± 8.4 months). The 3DS group, however, showed better metrics with osteotomy+lateralization+K wire fixation, tourniquet duration, and number of fluoroscopies at 12.4 ± 1.2 minutes, 41.5 ± 3.8 minutes, 2.5 ± 0.6 times. In contrast, the TS group recorded 17.1 ± 1.5 minutes, 50.8 ± 3.4 minutes, and 3.3 ± 0.8 times, respectively (P <.001 for all). The 3DS group also achieved a more significant restoration of the IM angle (P < .001). Postsurgery, the 3DS group demonstrated superior outcomes in FM head lateralization, FM shortening, and plantar displacement (P <.001, P <.001 and P = .006, respectively, for all metrics). Only 1 patient in the 3DS group experienced a pin-tract infection, which was treated with wound care and oral antibiotics. CONCLUSION: Simulating surgery on a 3D model and using it as a guide significantly enhances surgical outcomes. Benefits include reduced operation time, tourniquet duration, decreased fluoroscopy usage, and improved first-ray alignment. The 3DS method also ensures better lateralization of the first metatarsal head and correction of the IM. Although 3D model-assisted HV chevron osteotomy surgery provides ideal deformity correction, it does not significantly affect postoperative functional outcomes. LEVEL OF EVIDENCE: Level I, Therapeutic Study. Cite this article as:Süer O, Özer MA, Govsa F, Öztürk AM, Aktuglu SK. Impact of surgery simulation using a 3-dimensional printed model on outcomes of hallux valgus surgery with distal chevron osteotomy: A randomized controlled trial. Acta Orthop Traumatol Turc., 2024;58(2):95-101.