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.

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.

Patient-specific three-dimensional printing spine model for surgical planning in AO spine type-C fracture posterior long-segment fixation.

OBJECTIVE: The aim of this study was to compare duration of surgery, intraoperative fluoroscopy exposure, blood loss and the accuracy of pedicular screw placement between 3D model-assisted surgery and conventional surgery for AO spinal C-type injuries. METHODS: In this study 32 patients who were admitted with thoracolumbar AO spinal C-type injuries were included. These patients were divided randomly into two groups of 16 where one group was operated on using conventional surgery and the other group was operated on using 3D model-assisted surgery. During surgery, instrumentation time, amount of blood loss and intraoperative fluoroscopy exposure were recorded. Moreover, the status of the screws in the pedicles was assessed as described by Learch and Wiesner's and regional sagittal angles (RSA) were measured preop and postoperatively. RESULTS: It was found that there was a statistically significant difference in instrumentation time, blood loss and intraoperative fluoroscopy exposure in the 3D model-assisted surgery group (61.9 ± 4.7 min, 268.4 ± 42.7 ml, 16.3 ± 1.9 times) compared to the conventional surgery group (75.5 ± 11.0 min, 347.8 ± 52.2 mL, 19.7 ± 2.4 times) (t=4.5325, P < 0.0001 and t=4.7109, P < 0.0001 and t=4.4937, P < 0.0001, respectively) Although the screw misplacement rate of the conventional surgery group was higher than that of the 3D model-assisted surgery group, the only statistically significant difference was in the medial axial encroachment (t=5.101 P=0.02) . There was no severe misplacement of pedicle screws in either group. There were no statistically significant differences between postoperative RSA angles and were in both groups restored significantly. CONCLUSION: The results of this study have shown us that the 3D model helps surgeons see patients' pathoanatomy and determine rod lengths, pedicle screw angles and lengths preoperatively and peroparatively, which in turn shortens operative time, reduces blood loss and fluoroscopy exposure. LEVEL OF EVIDENCE: Level I, Therapeutic Study.

Evaluation of the effects of using 3D - patient specific models of displaced intra - articular calcaneal fractures in surgery.

BACKGROUND: It was aimed to compare conventional surgery and three-dimensional (3D) model-assisted surgery used in the treatment of calcaneal fractures. MATERIALS & METHODS: A total of 37 patients with unilateral calcaneal fractures were randomly divided into two groups as a conventional surgery group (n: 19) and a 3D model-assisted surgery group (n: 18). The preoperative, postoperative and last follow up angles of the Bohler and Gissane, calcaneal width and facet height were measured. The duration of the operation, blood loss volume, fluoroscopy usage, instrumentation time for both groups were recorded. Finally, the follow-up AOFAS scores were evaluated. A questionnaire was used to determine the perceptions of the resident doctors about the 3D model. RESULTS: The duration of the operation, blood loss volume, fluoroscopy usage, instrumentation time for 3D model-assisted surgery group were 83.3 ± 4.6 minutes, 83.6 ± 4.6 ml, 6.8 ± 1.4 times and 13.0 ± 0.8 weeks, and as for conventional group they were 130.0 ± 5.8 minutes, 105.1 ± 5.6 minutes, 11.7 ± 1.5 ml, 22.2 ± 2.4 times and 13.3 ± 0.8 weeks, respectively (p < 0.0001). The both groups significantly restored Bohler angle, Gissane angle, calcaneal width and calcaneal facet height after operation (p < 0.0001). The 3D model-assisted group was significantly more succesful in restoration and protection of achieved correction of calcanel facet height (p < 0.0001). The difference was determined among the groups at the final follow-up examination with respect to the amount of change according the values achieved post-op. were significant in Bohler angle (p < 0.001), calcaneal facet height (p < 0.0001) and calcaneal widht (p = 0.017). There was no significant difference between AOFAS scores of the two groups at last follow-up. Resident doctors exhibited high scores of overall satisfaction with the use of a 3D printing model. CONCLUSIONS: Compared to the conventional group, the 3D model-assisted group provide successful intervention and reduce operation, instrumentation time and the fluoroscopy usage with less blood loss. Performing 3D-assisted surgery helps the quality of reduction during the surgery and stability of internal fixation to protect achieved reduction at follow-up more succesfully.

Three-Dimensional Printed Anatomical Models Help in Correcting Foot Alignment in Hallux Valgus Deformities.

BACKGROUND: Hallux valgus (HV) is the most common pathologic entity affecting the great toe. The goal of corrective surgery is to restore foot mechanics and provide pain relief. The purpose of the study was to create individual angle using life-size foot models with three-dimensional (3D) printing technology to design a section on HV osteotomy. MATERIALS AND METHODS: Ten female patients with a diagnosis of HV were included. Radiologic [HV angle and intermetatarsal (IM) angle] and clinical [American Orthopaedic Foot and Ankle Score (AOFAS)] assessment was done pre- and postoperatively. All the operations were planned together with 3D life-size models generated from computed tomography (CT) scans. Benefits of using the 3D life-size models were noted. The 3D model's perception was evaluated. RESULTS: The mean AOFAS score, mean HV, and IM angles had improved significantly (P < 0.05). The visual and tactile inspection of 3D models allowed the best anatomical understanding, with faster and clearer comprehension of the surgical planning. At the first tarsometatarsal joint, the HV models showed significantly greater dorsiflexion, inversion, and adduction of the first metatarsal relative to the medial cuneiform. At the first metatarsophalangeal joint, the HV models showed significantly greater eversion and abduction of the first proximal phalanx relative to the first metatarsal. It provided satisfactory results about operation time and blood loss. 3D model's perception was statistically significant (P < 0.05). CONCLUSION: 3D models help to transfer complex anatomical information to clinicians, which provide guidance in the preoperative planning stage, for intraoperative navigation. It helps to create a patient-specific angle section on osteotomy to correct IM angle better and improve postoperative foot function. The 3D personalized model allowed for a better perception of information when compared to the corresponding 3D reconstructed image provided.

A retrospective comparison of the conventional versus three-dimensional printed model-assisted surgery in the treatment of acetabular fractures.

OBJECTIVE: The aim of this study was to compare the clinical and radiological outcomes of the conventional versus individualized three-dimensional (3D) printing model-assisted pre-contoured plate fixation in the treatment of patients with acetabular fractures. METHODS: The data from 18 consecutive patients who underwent surgery for the acetabular fractures were retrospectively analyzed. The patients were divided into two groups (9 in each): conventional and 3D printed model-assisted. The groups were then compared in terms of the duration of surgery, time of instrumentation, time of intraoperative fluoroscopy, and volume of blood loss. The quality of the fracture reduction was also evaluated postoperatively by radiography and computed tomography in both the groups. The quality of the fracture reduction was defined as good (<2 mm) or fair (>2 mm) based on the amount of displacement in the acetabulum. RESULTS: The conventional group included 9 patients (9 males; mean age=41.7 years; age range=16-70) with a mean follow-up of 11.9 months (range=8-15); the 3D printed model-assisted group consisted of 9 patients (9 males; mean age=46.2 years; age range=30-66) with a mean follow-up of 10.33 months (range=7-17). The average duration of surgery, mean time of instrumentation, time of intraoperative fluoroscopy, and mean volume of blood loss were 180.5±9 minutes, 36.2±3.6 minutes, 6±1 times, and 403.3±52.7 mL in the 3D printed model-assisted group, and 220±15.6 minutes, 57.4±10.65 minutes, 10.4±2.2 times, and 606.6±52.7 mL in the conventional group, respectively. Procedurally, the average duration of surgery, mean time of instrumentation, and mean time of fluoroscopy were significantly shorter, and the mean volume of blood loss was significantly lower in the 3D printed model-assisted group (p<0.05). The quality of the fracture reduction was good in 7 patients (78%) in the conventional group and 8 patients (89%) in the 3D printed model-assisted group. CONCLUSION: As compared with the conventional surgery, the 3D printing model-assisted pre-contoured plate fixation technique can improve the clinical and radiological outcomes of the acetabular fractures, with shorter surgery, instrumentation, intraoperative fluoroscopy times, and blood loss. LEVEL OF EVIDENCE: Level III, Therapeutic study.

Surgical advantages of using 3D patient-specific models in high-energy tibial plateau fractures.

PURPOSE: Treatment of tibial plateau fractures are difficult due to the intra-articular nature of the proximal tibia and extensive involvement of the soft tissue envelope. In this study, we investigated the surgical experience acquired using digitally designed life-size fracture models to guide as a template to place plates and screws in the treatment of tibial plateau fractures and anatomic reduction of joint. METHODS: 20 tibial plateau frature patients were divided into two equal surgery groups as conventional versus 3D model assisted. The fracture line angles, depression depth, and preoperative/postoperative Rasmussen knee score were measured for each patient. RESULTS: The duration of the operation, blood loss volume, turniquet time and number of intraoperative fluoroscopy was 89.5 ± 5.9 min, 160.5 ± 15.3 ml, 74.5 ± 6 min and 10.7 ± 1.76 times, for 3D printing group and 127 ± 14.5 min, 276 ± 44.8 ml, 104.5 ± 5.5 min and 18.5 ± 2.17 times for the conventional group, respectively. 3D model-assisted group indicated significantly shorter operation time, less blood loss volume, shorter turniquet and fluoroscopy times, and better outcome than the conventional one. CONCLUSIONS: The customized 3D model was user friendly, and it provided a radiation-free tibial screw insertion. The use of these models assisted surgical planning, maximized the possibility of ideal anatomical reduction and provided individualized information concerning tibial plateau fractures.

Patient-Specific Three-Dimensional Model for a Safe Surgical Pathway in Sacral Chondrosarcoma.

Sacral tumors are amongst the most challenging procedures to treat because of the complex anatomy. This study determined whether patient-specific models change preoperative planning decisions made in preparation for en bloc resection of complex sacral mass surgical procedures. Imaging showed a big encapsulated mass at the S2-3 level involving the neural foramina and obscuring the nerve roots. High-resolution images were acquired and utilized to generate a patient-specific 3D tumor model. The visual and tactile inspection of 3D models allowed the best anatomical understanding, with faster and clearer comprehension of the surgical anatomy. The 3D sacral model was for observation of previously unapparent anatomical details; with this new technology, surgeon can observe their planned surgical intervention, explore the patient-specific anatomy and extension of the tumor, and sharpen their procedure choices. Moreover, multiple planes showed how far the angles on the plane would extend for osteotomy of the sacrum. Another result was identifying correct guides and safe venture landmarks. The study helped to establish safe osteotomy line wherever the nerve roots were retained and enabled osteotomy by preserving bilaterally the S1 and S2 nerve roots for wide excision of wide excision of primary sacral tumor to get adequate bowel and bladder functions. Finally, it helped to determine whether or not the remaining bone in the sacrum is sufficient for spinopelvic stability and needed fixation. It was decided spinopelvic fixation was not necessary for this case. Surgical intervention of sacral tumors varies depending on the tumor, its size, extension, and location. Surgery can have profound risks including unnecessary nerve root resection spinopelvic instability and suboptimal oncological resection. 3D models help to transfer complex anatomical information to clinicians and provide guidance in the preoperative planning stage, for intraoperative navigation and for surgical training purposes.