Percutaneous endoscopic transforaminal discectomy and unilateral biportal endoscopic discectomy for lumbar disc herniation: a comparative analysis of learning curves.

OBJECTIVE: The purpose of this study was to investigate the learning curve of percutaneous endoscopic transforaminal discectomy (PETD) and interlaminar unilateral biportal endoscopic discectomy (UBED) in the treatment of lumbar disc herniation (LDH). METHODS: Between 2018 and 2023, 120 consecutive patients with lumbar disc herniation (LDH) treated by endoscopic lumbar discectomy were retrospectively included. The PETD group comprised 87 cases, and the UBED group comprised 33 cases. Cumulative sum analysis was used to evaluate the learning curve, with the occurrence of complications or unresolved symptoms defined as surgical failure, and variables of different phases of the learning curve being compared. RESULTS: The learning curve analysis identified the cutoff point at 40 cases in the PETD group and 15 cases in the UBED group. In the mastery phase, both PETD and UBED demonstrated a significant reduction in operation times (approximately 38 min for PTED and 49 min for UBED). In both PETD and UBED groups, the surgical failure rates during the learning and mastery phases showed no statistically significant differences. The visual analogue scale at the last follow-up was significantly lower than before surgery in both the PETD and UBED groups. CONCLUSION: PETD and UBED surgery are effective in the treatment of LDH with a low incidence of complications. However, achieving mastery in PETD necessitates a learning curve of 40 cases, while UBED requires a minimum of 15 cases to reach proficiency.

Is there a risk of further displacement of the fractured fragment into the spinal canal in osteoporotic vertebral burst fractures after unilateral PKP? A prospective study.

BACKGROUND CONTEXT: The optimal treatment for osteoporotic vertebral burst fracture (OVBF) without neurological symptoms is still a matter of debate. PURPOSE: To evaluate the safety and efficacy of percutaneous kyphoplasty (PKP) for OVBF. STUDY DESIGN: The study is a prospective study and is registered in the China Clinical Trials Registry with the registration number ChiCTR-OOC-17013227. PATIENT SAMPLE: The study involved 119 patients with 137 fractured vertebrae who underwent unilateral PKP for OVBF. OUTCOME MEASURES: The measurements were carried out independently by two physicians and measured with picture archiving and communication system (PACS) and ImageJ software (National Institutes of Health, Bethesda, MD, USA). METHODS: The change in the spinal canal area and posterior wall protrusions (PWP) were measured before and after surgery via three-dimensional computed tomographic imaging (CT). Preoperative, postoperative, and final follow-up standing X-rays were used to measure the height of the anterior wall (HAW), height of the posterior wall (HPW), and local kyphotic angle (LKA). Additionally, visual analogue scale (VAS) and the Oswestry Disability Index (ODI) were also determined. RESULTS: Among the 137 vertebrae assessed, 79 exhibited an increased postoperative canal area, while 57 showed a decrease, with mean values of 8.28±6.871 mm² and -9.04±5.991 mm², respectively. Notably, no significant change in postoperative canal area was identified on the entire dataset (p>.01). There was a significant decrease between median preoperative (3.9 [IQ1-IQ3=3.3-4.8] mm) and postoperative (3.7 [IQ1-IQ3=3.0-4.4] mm) PWP (p<.01). Preoperative and postoperative HAW measurements were 19.4±6.1 mm and 23.2±5.2 mm, respectively (p<.01). However, at the final follow-up, the HAW was lower than the postoperative value. The HPW was also significantly improved after surgery (p<.01), but at the final follow-up, it was significantly decreased compared with the postoperative measurement. Following surgery, KA was significantly corrected (p<.01); however, at the final follow-up, relapse was detected (average KA: 18.4±10.3°). At the final follow-up, both VAS and ODI were significantly improved compared with the preoperative period (p<.01). As for complications, 50 patients experienced cement leakage, and 16 patients experienced vertebral refracture. All patients did not develop neurological symptoms during the follow-up. CONCLUSIONS: OVBF without neurological deficits showed significant improvement in symptoms during the postoperative period after PKP. There was no notable alteration in the spinal canal area, but a significant decrease in PWP was observed. Consequently, we posit that PKP stands as a secure and efficacious surgical intervention for treating OVBF cases devoid of neurological symptoms.

Hounsfield unit for assessing asymmetrical loss of vertebral bone mineral density and its correlation with curve severity in adolescent idiopathic scoliosis.

Background: Low bone mass concomitantly occurs in patients with adolescent idiopathic scoliosis (AIS) and can persist until skeletal maturity. The purpose of this study was to assess the asymmetrical loss of vertebral bone mineral density (vBMD) and its correlation with curve severity in patients with AIS using Hounsfield unit (HU) values measured from computed tomography scans. Methods: A total of 93 AIS patients were retrospectively recruited. The HU values of the vertebral body (VB-HU) and pedicle screw trajectory (PST-HU) were measured from four vertebrae above (Apex - 4) to four below (Apex + 4) the apical vertebra (Apex) of the major curve. The VB-HU and PST-HU at the upper end vertebra, Apex, and lower end vertebra within the concave and convex sides of the major and minor curves and stable vertebrae were obtained. Results: A significant correlation was found between the Cobb angle and VB-HU at the periapical levels of the major curve. VB-HU and PST-HU at periapical levels were significantly greater within the concavity than the convexity of both major and minor curves. The asymmetric ratios of VB-HU and PST-HU were significantly correlated with the major curve Cobb angle, peaked at the apex, and gradually diminished from the apex to the end vertebrae. The asymmetrical loss of vBMD aggravated with the progression of curve severity, presenting as VB-HU, significantly decreased within the convexity and insignificantly decreased within the concavity of the major curve. Conclusion: The asymmetrical loss of vBMD was associated with the progression of curve severity in AIS. For patients with severe AIS, the distraction of the pedicle screws at the concave side should be a priority in correcting the major curve, and supplemental anchors and larger-sized screws should be placed within the convex side around the apex of the major curve to reduce the risk of screw loosening after surgery.

Do sandwich vertebral bodies increase the risk of post-augmentation fractures? A retrospective cohort study.

Until now, there have been only a few retrospective studies that focused on the outcomes of sandwich vertebral bodies (SVBs). This is a long-term retrospective cohort study to investigate the SVBs. We found that although patients with SVBs had a relatively high risk of developing new fractures after VA, the incidence rate of new fractures was not significantly different from that of the control group. However, the statistical power of this study was very limited. Therefore, and because the refracture rate in these patients is substantial, routine long-term monitoring of patients after VA for osteoporosis is strongly recommended. BACKGROUND: Sandwich vertebral bodies (SVBs) are intact unaugmented vertebral bodies between two previously augmented vertebrae. Until recently, only a few studies have reported the outcomes and strategies for SVBs. This retrospective cohort study aimed to describe the clinical features and incidence of new fractures in patients with SVBs. METHODS: The clinical data were collected from 179 patients with 237 symptomatic osteoporotic vertebral compression fractures who underwent vertebral augmentation (VA). Among them, 23 patients with 24 levels of SVBs were included. Spinal radiographs (X-ray and CT) of all patients were evaluated prior to surgery 1 day after primary VA and during follow-up. RESULTS: All patients successfully underwent PKP with an average follow-up period of 21.48 months. Asymptomatic cement leakage occurred in four patients (17.4%), and eight patients (34.8%) developed new fractures following primary PKP, including four sandwich, six adjacent, four remote vertebral fractures, and one re-collapse of cemented vertebrae. The incidence of new fractures in the SVB and control groups was 16.7% (4/24) and 13.0% (6/46), respectively, but there was no significant difference. CONCLUSIONS: Although patients with SVBs had a relatively high risk of developing new fractures after VA, the incidence rate of new fractures was not significantly different from that of the control group. However, the statistical power of this study was very limited. Therefore, and because the refracture rate in these patients is substantial, routine long-term monitoring of patients after VA for osteoporosis is strongly recommended.

Posterior thoracolumbar hemivertebra resection and short-segment fusion in congenital scoliosis: surgical outcomes and complications with more than 5-year follow-up.

BACKGROUND: Treatment of congenital hemivertebra is challenging and data on long-term follow-up (≥ 5 years) are lacking. This study evaluated the surgical outcomes of posterior thoracolumbar hemivertebra resection and short-segment fusion with pedicle screw fixation for treatment of congenital scoliosis with over 5-year follow-up. METHODS: This study evaluated 27 consecutive patients with congenital scoliosis who underwent posterior thoracolumbar hemivertebra resection and short-segment fusion from January 2007 to January 2015. Segmental scoliosis, total main scoliosis, compensatory cranial curve, compensatory caudal curve, trunk shift, shoulder balance, segmental kyphosis, and sagittal balance were measured on radiographs. Radiographic outcomes and all intraoperative and postoperative complications were recorded. RESULTS: The segmental main curve was 40.35° preoperatively, 11.94° postoperatively, and 13.24° at final follow-up, with an average correction of 65.9%. The total main curve was 43.39° preoperatively, 14.13° postoperatively, and 16.06° at final follow-up, with an average correction of 60.2%. The caudal and cranial compensatory curves were corrected from 15.78° and 13.21° to 3.57° and 6.83° postoperatively and 4.38° and 7.65° at final follow-up, with an average correction of 69.2% and 30.3%, respectively. The segmental kyphosis was corrected from 34.30° to 15.88° postoperatively and 15.12° at final follow-up, with an average correction of 61.9%. A significant correction (p < 0.001) in segmental scoliosis, total main curve, caudal compensatory curves and segmental kyphosis was observed from preoperative to the final follow-up. The correction in the compensatory cranial curve was significant between preoperative and postoperative and 2-year follow-up (p < 0.001), but a statistically significant difference was not observed between the preoperative and final follow-up (p > 0.001). There were two implant migrations, two postoperative curve progressions, five cases of proximal junctional kyphosis, and four cases of adding-on phenomena. CONCLUSION: Posterior thoracolumbar hemivertebra resection after short-segment fusion with pedicle screw fixation in congenital scoliosis is a safe and effective method for treatment and can achieve rigid fixation and deformity correction.

Percutaneous vertebroplasty (PVP) to treat specialized type of endplate fractures around the Schmorl's node: a prospective study of 65 patients.

BACKGROUND: The Schmorl's nodes (SNs) are defined as the herniation of the intervertebral disc into the vertebral body. Endplate fractures around the Schmorl's node could result in severe back pain that is similar to vertebral compression fractures. The objective of this study was to prospectively analyze the surgical effectiveness and safety of percutaneous vertebroplasty (PVP) for endplate fractures around the SNs. METHODS: Seventy-one consecutive patients with the fresh endplate fracture around SNs from October 2017 to February 2018 were enrolled in this study. The visual analog scale (VAS) and Oswestry disability index (ODI) scores of low back pain were evaluated in all patients preoperatively, postoperatively, and at 1 month, 6 months, and 1 year after primary single level PVP. Surgery-related data including duration of the operation, injected cement volumes, and surgical complications were recorded. RESULTS: Sixty-five patients with fresh endplate fractures around the SNs were treated successfully via percutaneous vertebroplasty. Our study showed that the VAS scores and ODI scores of patients were obviously improved after operation. Cement leakage into the disc space occurred in 5 patients (7.7%), and adjacent segment refractures occurred in 2 patients (3.1%). No other surgical complications, including infections or nerve root injuries were encountered. CONCLUSIONS: Based on the results of this prospective study, PVP was an effective and safe procedure for endplate fractures around the SNs. TRIAL REGISTRATION: ChiCTR, ChiCTR1800016453 . Registered 2 June 2018-retrospectively registered, http://www.chictr.org.cn/com/25/historyversionpuben.aspx?regno=ChiCTR1800017602.

The feasibility for a novel minimally invasive surgery-percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) for the treatment of lumbar degenerative diseases: a cadaveric experiment.

BACKGROUND: The objective of the study was to evaluate our innovative percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) for the treatment of lumbar degenerative diseases. METHODS: Two fresh-frozen human cadavers with soft tissues were donated for the experiment. Both cadavers had no history of previous spine surgery. The PE-TLIF surgery was performed on 3 levels (L4-5 of the first one, and L3-4, L4-5 of the second one) in October 2015. The PE-TLIF technique mainly included the following aspects: primary guide pins and a specially designed superior articular process (SAP) guide insertion, working channel setup, endoscopic decompression and fusion, and pedicle screw implantation and fixation. Under the surveillance of C-arm fluoroscope, four primary guide pins were inserted. The inferior primary guide in the hypothetically symptomatic side was confirmed as the first guide pin. At the end of the first guide pin, the specially designed SAP guide was installed. The secondary guide pin was inserted in the SAP via self-designed SAP guide. Under the protection cannula, part of the superior articular process was removed by oriented SAP resection device, so the working channel was smoothly put through the Kambin's triangle. The endoscope was inserted close to the exiting nerve root. Rotation of the working channel kept the nerve root out of it. RESULTS: Three levels of PE-TLIF were successfully performed in two cadavers. Self-designed SAP guide made the secondary guide pin inserting the SAP accurately. Decompression was adequate and the traversing nerve root was relieved. Three aimed intervertebral levels are implanted with two 7-mm-high PEEK cages and one expandable cage. The expandable cage could be adjusted from 8 mm to 13 mm. Surgical incisions included four 15 mm incisions for percutaneous screw fixation and one 12 mm incision for working channel. There was no nerve injury during the operations. CONCLUSIONS: Our present results showed that the novel minimally invasive surgery PE-TLIF was feasible for the treatment of lumbar degenerative diseases.

Risk factors of cemented vertebral refracture after percutaneous vertebral augmentation: a systematic review and meta-analysis.

To evaluate the risk factors of cemented vertebral refracture after percutaneous vertebral augmentation (PVA) for patients with osteoporotic vertebral compression fractures (OVCFs). We performed a literature search on cemented vertebral refracture after PVA using the PubMed, EMBASE, and Cochrane Library medical databases. The clinical data, including literature information, basic patient information, observational factors, and interventional factors, were extracted by two authors. The pooled results and related heterogeneity of each factor between the refracture group and the non-refracture group were evaluated using Review Manager software 5.35. A total of 3185 patients from 10 studies were included, with 195 patients in the refracture group and 2990 patients in the non-refracture group. The mean follow-up duration was 18.9 months. According to the meta-analysis, age, low bone marrow density (BMD), intravertebral cleft (IVC), high anterior vertebral height (AVH) restoration/high Cobb angle restoration, and low cement dose were the risk factors of cemented vertebral refracture after PVA. Our results showed that age, low BMD, IVC, high AVH restoration, high Cobb angle restoration, and low cement dose were the risk factors for cemented vertebral refracture after PVA.

The treatment of osteoporotic thoraco-lumbar burst fractures by unilateral percutaneous kyphoplasty: A prospective observation study.

OBJECTIVE: Osteoporotic thoraco-lumbar burst fractures with serious pain are very common, and the optimal treatment of burst fractures without any neurological deficits has not yet been properly codified. The objective of this study was to evaluate prospectively the clinical effects and pain relief of unilateral percutaneous kyphoplasty (PKP) on osteoporotic thoraco-lumbar burst fractures. METHODS: Forty-six patients with osteoporotic thoraco-lumbar burst fractures were treated by PKP in our hospital from January 2016 to January 2017. The height of posterior wall (HPW), the height of anterior wall (HAW) and kyphotic angle (KA) were measured via x-ray radiographs before surgery, one day after surgery and at final follow-up. Visual analogue scale (VAS) score and the oswestry disability index (ODI) score were evaluated preoperatively, postoperatively and at final follow-up. All the patients with osteoporotic thoraco-lumbar burst fractures were treated by unilateral PKP. Radiological evaluation (anteroposterior and lateral x-ray radiographs and CT) was performed. RESULTS: All patients were followed-up, and the mean follow-up was 28.8 ± 7.0 months. The preoperative HAW was 20.1 ± 2.3 mm, and the HAW was significantly improved to 22.9 ± 2.4 mm after operation (p < .05), and at the final follow-up, the HAW was 19.9 ± 2.1 mm, which was lower than the postoperative HAW. The HPW was also significantly corrected after surgery (p < .05). There were no significant differences between postoperative HPW and HPW at the final follow-up (p > .05). The KA was significantly corrected after operation (p < .05), but relapse occurred at the final follow-up, and at the final follow-up, the average of KA was 19.4 ± 1.6 degree. The VAS and ODI were significantly improved at the final follow-up compared to the preoperative period (p < .05). Cement leakage was found in eight patients, and adjacent vertebral fracture (VF) was found in two patients. CONCLUSIONS: Our results showed that unilateral PKP acquired satisfactory treatment effect and pain relief in the management of osteoporotic thoraco-lumbar burst fractures. Meticulous evaluation of preoperative images and careful repetitious injection of cement are important to prevent cement leakage. SIGNIFICANCE: Our present results showed that unilateral PKP was an effective method to obtain satisfactory pain relief in the management of osteoporotic thoraco-lumbar burst fractures. It may a good indication for the patients with osteoporotic thoraco-lumbar burst fractures, and the patients could not tolerate the serious acute pain by conservative treatment.

Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion for the Treatment of Lumbar Spinal Stenosis: Preliminary Report of Seven Cases with 12-Month Follow-Up.

PURPOSE: The objective of this study was to investigate the preliminary effectiveness of percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) for the treatment of lumbar spinal stenosis (LSS). METHODS: From September 2016 to June 2017, a series of seven patients consisting of six females and one male with an average age of 55.25 years (range 43-77 years) who were diagnosed with LSS were involved in this study. All patients were treated by PE-TLIF. During perioperative and follow-up period, demographic data, operation time, intraoperative blood loss, Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria were evaluated and perioperative complications were documented. RESULTS: All patients were followed up for more than 12 months, with an average follow-up time of 15 (range 12-21) months. The mean VAS of back pain was 7.43 (range 6-8) preoperatively and 0.86 (range 0-2) at the final follow-up. The mean VAS of leg pain was 6.14 (range 4-9) preoperatively and 0.71 (range 0-1) at the final follow-up. The mean ODI was 53.57% (range 38%-63%) preoperatively and 15.57% (range 5%-26%) at the final follow-up. In three-month follow-up, continuous bone trabeculae bridging between intervertebral bodies was seen in 3 cases, and the remaining 4 cases could identify continuous bone trabeculae bridging at 6-month follow-up, reaching the standard of spinal intervertebral fusion. At the final follow-up, 4 patients were rated as excellent (4/7) and 3 patients were rated as good (3/7) according to the modified MacNab criteria. CONCLUSIONS: Our study suggested that percutaneous endoscopic transforaminal lumbar interbody fusion could acquire satisfactory treatment effects for the patients with lumbar spinal stenosis, even for the patient who could not afford general anesthesia.

Posterior Multiple-Level Asymmetrical Ponte Osteotomies for Rigid Adult Idiopathic Scoliosis.

OBJECTIVE: To evaluate the efficacy and safety of posterior multiple-level asymmetrical Ponte osteotomies for rigid adult idiopathic scoliosis. METHODS: A retrospective study was conducted for adult patients with rigid idiopathic scoliosis (flexibility of main curve <25%) who underwent one-stage multiple-level asymmetrical Ponte osteotomies with a minimum of 2-year follow-up between February 2009 and November 2015. The demographic data and surgical issues were collected, and the improvement of clinical function scores and radiologic parameters were obtained after surgery and during the follow-up to assess deformity correction, spinal balance, and clinical outcome. RESULTS: A total of 49 patients were included (10 male and 39 female) in this study, with an average age of 26.53 years old. The average follow-up was 28.37 ± 6.98 months. All the cases presented a significant improvement of the main curve and focal kyphosis from 85.62 ± 19.80° to 36.19 ± 16.74° and 53.98 ± 26.80° to 30.88 ± 18.69°, with a mean correction rate of 57.73% and 41.23%. The postoperative coronal and sagittal parameters were all significantly improved, except coronal balance. The mean operative time and blood loss were 267.86 ± 54.49 minutes and 838.78 ± 538.93 mL. All the clinical function scores of patients were significantly improved at the final follow-up. Only one patient had a complication related to surgical incision, with no neurologic complications occurring. CONCLUSIONS: The surgical procedure of multiple-level asymmetrical Ponte osteotomy is a safe and effective technique, with reduced operation time, blood loss, and complications, and may offer an appropriate option to address the problems of rigid adult idiopathic scoliosis.

Upper Instrumented Vertebrae Distal to T2 Leads to a Higher Incidence of Proximal Junctional Kyphosis During Growing-rod Treatment for Early Onset Scoliosis.

STUDY DESIGN: A retrospective case series. OBJECTIVE: We sought to evaluate the prevalence and risk factors of proximal junctional kyphosis (PJK) after growing-rod surgery in patients with early onset scoliosis (EOS). SUMMARY OF BACKGROUND DATA: Growing-rod surgery is the primary treatment in patients with progressive EOS when conservative treatment fails. PJK is one of the most commonly reported postoperative complications. MATERIALS AND METHODS: We retrospectively evaluated 50 patients (24 boys and 26 girls) diagnosed with EOS who underwent growing-rod surgery. Preoperative and follow-up demographic data, surgical strategies, and radiographic parameters were recorded and analyzed to identify PJK risk factors. RESULTS: The mean age of patients at the time of the initial surgery was 8.6±2.5 years. Mean follow-up was 33.5±10.8 months, and mean number of lengthening surgeries were 2.14±1.52. Twenty-eight of the surgical procedures were single growing-rod surgeries, of which 22 were dual growing-rod surgeries. The upper instrumented vertebrae (UIV) ranged from C6-T6, and the lower instrumented vertebrae ranged from L1-S1. Ultimately, PJK developed in 14 (28%) of 50 patients. Taller patients, UIV distal to T2, and greater postoperative upper thoracic scoliosis (UTS) were suspected potential risk factors of PJK during the univariate analysis (P<0.1). Multifactorial regression analysis confirmed that UIV distal to T2 (hazard ratio=5.474; P=0.044) and postoperative UTS >50 degrees (hazard ratio=1.049; P=0.046) were the independent risk factors of PJK during growing-rod treatment in patients with EOS. CONCLUSIONS: The prevalence of PJK was 28% during growing-rod treatment in EOS. The independent risk factors for PJK were UIV distal to T2 and postoperative UTS >50 degrees. It is important for spine surgeons to recognize these risk factors when planning surgeries, and counseling patients and families about this possible complication. LEVEL OF EVIDENCE: Level III.

Three-dimensional printing model improves morphological understanding in acetabular fracture learning: A multicenter, randomized, controlled study.

Conventional education results in unsatisfactory morphological understanding of acetabular fractures due to lack of three-dimensional (3D) details and tactile feedback of real fractures. Virtual reality (VR) and 3D printing (3DP) techniques are widely applied in teaching. The purpose of this study was to identify the effect of physical model (PM), VR and 3DP models in education of morphological understanding of acetabular fractures. 141 students were invited to participate in this study. Participants were equally and randomly assigned to the PM, VR and 3DP learning groups. Three-level objective tests were conducted to evaluate learning, including identifying anatomical landmarks, describing fracture lines, identifying classification, and inferring fracture mechanism. Four subjective questions were asked to evaluate the usability and value of instructional materials. Generally, the 3DP group showed a clear advantage over the PM and VR groups in objective tests, while there was no significant difference between the PM and VR groups. 3DP was considered to be the most valuable learning tool for understanding acetabular fractures. The findings demonstrate that 3DP modelling of real fractures is an effective learning instrument that can be used to understand the morphology of acetabular fractures and promote subjective interest.

CLINICAL APPLICATION OF A DRILL GUIDE TEMPLATE FOR PEDICLE SCREW PLACEMENT IN SEVERE SCOLIOSIS.

OBJECTIVE: To evaluate the accuracy and the effect of drill guide template for pedicle screw placement in severe scoliosis. METHOD: Eight patients with rigid scoliosis were enrolled, five males and three females, ranging from nine to 23 years old. A three-dimensional CT scan of the spine was performed and saved as a DICOM file type. The multi-level template was designed by Mimics software and manufactured according to the part of the most severe deformity. The drill template was placed on the corresponding vertebral surface. Pedicle screws were carefully inserted across the trajectory of the template. Postoperatively, the positions of the pedicle screws were evaluated by CT scan and graded for validation. RESULTS: No spinal cord injury or nerve damage occurred. All patients had satisfactory outcomes. The abnormalities and the measures observed during operation were the same as those found in the preoperative period. The position of the pedicle screws was accurate, according to the postoperative X-ray and CT scan. The rate of scoliosis correction was 60%. Compared with controls, surgery time, blood loss and radiation were significantly lower. CONCLUSION: With the application of multi-level template, the placement of pedicle screws shows high accuracy in scoliosis with shorter surgical time, less blood loss and less radiation exposure. Level of Evidence III, Retrospective Comparative Study.

OBJETIVO: Avaliar a precisão e o efeito da matriz de guia de broca para colocação de parafuso pedicular em escoliose grave. MÉTODO: Oito pacientes com escoliose rígida foram selecionados, sendo cinco homens e três mulheres na faixa etária de nove a 23 anos. Foi realizada TC tridimensional da coluna, gravada no formato DICOM. A matriz multinível foi desenhada pelo software Mimics e fabricada de acordo com a parte da deformidade mais grave. A matriz da broca foi colocada na superfície vertebral correspondente. Os parafusos pediculares foram cuidadosamente inseridos ao longo da trajetória da matriz. No pós-operatório, as posições dos parafusos pediculares foram avaliadas por TC e classificadas para validação. RESULTADOS: Não ocorreu nenhuma lesão da medula espinhal nem lesão de nervos. Todos os pacientes tiveram desfechos satisfatórios. As anormalidades e as medidas observadas durante a operação foram as mesmas encontradas no pré-operatório. A posição dos parafusos pediculares foi precisa, de acordo com a radiografia e a TC pós-operatórias. A taxa de correção de escoliose foi de 60%. Em comparação com os controles, o tempo de cirurgia, a perda de sangue e a radiação foram significantemente menores. CONCLUSÃO: Com a aplicação da matriz multinível, a colocação dos parafusos pediculares mostra alta precisão na escoliose, com menor tempo cirúrgico, menos perda de sangue e menor exposição à radiação. Nível de Evidência III, Estudo Retrospectivo Comparativo.

Biomechanical evaluation of a novel dualplate fixation method for proximal humeral fractures without medial support.

BACKGROUND: Comminuted fractures of the proximal humerus are generally treated with the locking plate system, and clinical results are satisfactory. However, unstable support of the medial column results in varus malunion and screw perforation. We designed a novel medial anatomical locking plate (MLP) to directly support the medial column. Theoretically, the combined application of locking plate and MLP (LPMP) would directly provide strong dual-column stability. We hypothesized that the LPMP could provide greater construct stability than the locking plate alone (LP), locking plate combined with a fibular graft (LPSG), and locking plate combined with a distal radius plate (LPDP). METHODS: LP, LPMP, LPSG, and LPDP implants were instrumented into the finite element model of a proximal humeral fracture. Axial, shear, and rotational loads were applied to the models under normal and osteoporotic bone conditions. The whole simulation was repeated five times for each fixator. To assess the biomechanical characteristics, the construct stiffness, fracture micromotion, stress distribution, and neck-shaft angle (NSA) were compared. RESULTS: The LPMP group showed significantly greater integral and regional construct stiffness, and endured less von Mises stresses, than the other three fixation methods. The stresses on the lateral locking plate were dispersed by the MLP. The LPMP group showed the least change in NSA. CONCLUSIONS: From the finite element viewpoint, the LPMP method provided both lateral and medial direct support. The LPMP system was effective in treating proximal humeral fracture with an unstable medial column.

CLINICAL APPLICATION OF A DRILL GUIDE TEMPLATE FOR PEDICLE SCREW PLACEMENT IN SEVERE SCOLIOSIS / APLICAÇÃO CLÍNICA DE MATRIZ DE GUIA DE BROCA PARA COLOCAÇÃO DE PARAFUSO PEDICULAR EM ESCOLIOSE GRAVE

ABSTRACT Objective: To evaluate the accuracy and the effect of drill guide template for pedicle screw placement in severe scoliosis. Method: Eight patients with rigid scoliosis were enrolled, five males and three females, ranging from nine to 23 years old. A three-dimensional CT scan of the spine was performed and saved as a DICOM file type. The multi-level template was designed by Mimics software and manufactured according to the part of the most severe deformity. The drill template was placed on the corresponding vertebral surface. Pedicle screws were carefully inserted across the trajectory of the template. Postoperatively, the positions of the pedicle screws were evaluated by CT scan and graded for validation. Results: No spinal cord injury or nerve damage occurred. All patients had satisfactory outcomes. The abnormalities and the measures observed during operation were the same as those found in the preoperative period. The position of the pedicle screws was accurate, according to the postoperative X-ray and CT scan. The rate of scoliosis correction was 60%. Compared with controls, surgery time, blood loss and radiation were significantly lower. Conclusion: With the application of multi-level template, the placement of pedicle screws shows high accuracy in scoliosis with shorter surgical time, less blood loss and less radiation exposure. Level of Evidence III, Retrospective Comparative Study.

RESUMO Objetivo: Avaliar a precisão e o efeito da matriz de guia de broca para colocação de parafuso pedicular em escoliose grave. Método: Oito pacientes com escoliose rígida foram selecionados, sendo cinco homens e três mulheres na faixa etária de nove a 23 anos. Foi realizada TC tridimensional da coluna, gravada no formato DICOM. A matriz multinível foi desenhada pelo software Mimics e fabricada de acordo com a parte da deformidade mais grave. A matriz da broca foi colocada na superfície vertebral correspondente. Os parafusos pediculares foram cuidadosamente inseridos ao longo da trajetória da matriz. No pós-operatório, as posições dos parafusos pediculares foram avaliadas por TC e classificadas para validação. Resultados: Não ocorreu nenhuma lesão da medula espinhal nem lesão de nervos. Todos os pacientes tiveram desfechos satisfatórios. As anormalidades e as medidas observadas durante a operação foram as mesmas encontradas no pré-operatório. A posição dos parafusos pediculares foi precisa, de acordo com a radiografia e a TC pós-operatórias. A taxa de correção de escoliose foi de 60%. Em comparação com os controles, o tempo de cirurgia, a perda de sangue e a radiação foram significantemente menores. Conclusão: Com a aplicação da matriz multinível, a colocação dos parafusos pediculares mostra alta precisão na escoliose, com menor tempo cirúrgico, menos perda de sangue e menor exposição à radiação. Nível de Evidência III, Estudo Retrospectivo Comparativo.

[Effect of wound healing of orthopedic surgery in human immunodeficiency virus infected patients with perioperative adjuvant treatments].

OBJECTIVE: To observe the early wound healing of orthopedic surgery in human immunodeficiency virus (HIV) carrier patients treated with optimized auxiliary treatments. METHODS: During a period of 48 months, according to the inclusion and exclusion criteria plus CD4⁺ T lymphocyte count, the patients scheduled for orthopedic surgery (including HIV positive and negative) were divided into group A (HIV positive, CD4<500/ml) with optimized auxiliary treatments, group B (HIV positive, CD4 ≥ 500/ml) and group C (HIV negative) on prophylactic antibiotic therapy alone. Wound healing of 3 groups were observed postoperatively. The rates of clinical wound infection were compared among 3 groups. RESULTS: A total of 471 cases (n = 79, HIV+; n = 392, HIV-) were selected due to fresh fracture (n = 544, 77.28%), fracture of spine (n = 57, 12.31%), mal-union (n = 13, 2.76%), aseptic necrosis (n = 15, 3.18%) and osteoarthritis (n = 21, 4.46%). During surgery, early open reduction and plate screw internal fixation (group A, n = 23; group B, n = 21; group C, n = 274); pedicle screw internal fixation (group A, n = 5; group B, n = 6; group C, n = 47); total joint replacement (group A, n = 3; group B, n = 4; group C, n = 8); interlocking intramedullary nail fixation (group A, n = 7; group B, n = 4; group C, n = 35) and other operations (group A, n = 3; group B, n = 3; group C, n = 28). For infections, 2 cases (4.88%) were observed in group A, 3 (5.26%) in group B and 26 (6.63%) in group C. The differences were statistically insignificant. CONCLUSION: Reasonable perioperative adjuvant treatments, including use of antibiotic, nutritional supports, immunomodulators and anti-retroviral drugs, are offered to HIV infected patients undergoing orthopedic surgery. Their risks of postoperative wound infection may be controlled.

[A clinical study of 19 cases of unrelated heterogenic bone marrow transplantation].

OBJECTIVE: To investigate the outcomes and problems in unrelated bone marrow transplantation (URD-BMT). METHODS: 19 patients received URD-BMT in our institute from August 1998 to February 20, 2001. The diagnoses included chronic myelogenous leukemia (CML) (n = 9), acute lymphoblastic leukemia (ALL) (n = 6), acute myelogenous leukemia (AML) (n = 2), MDS-RAEB (n = 1) and beta-thalassemia major (n = 1). 19 pairs were HLA-A, HLA-B, HLA-DR matched with low resolution technique; 8 of them were HLA-A, B or DRB1 mismatched with high resolution technique. 2 patients received a TBI conditioning regimen, the other 17 received BUCY or modified BUCY regimen. Bone marrow was infused to 18 recipients via aorta and one through intravenous route. As graft versus host disease (GVHD) prophylaxis, all patients received CSA and MTX, 9 patients received ATG, 1 patient received CD(3)/CD(25) and 7 patients received mycophenolate mofetil. T-cell depletion technique was applied in one patient. Statistics Kaplan-Meier plots for time-dependent analysis (survival, acute GVHD and engraft). Fisher' exact test was used for univariate analysis of risk factors. RESULTS: Apart from 2 patients who were under observation and one patient with CML suffered from late rejection. 16 out of the 19 patients had all been persistently engrafted. Relapse happened on day 60 in one patient who had advanced refractory ALL. Early infection within 5 weeks after BMT with discernable pathogens was documented in 5 patients. CMV infection occurred in 10 patients. 13 out of the 19 patients have survived. The disease free survival rate was 58.3%. The cumulative incidence of acute GVHD grades II approximately IV was 53.0%. CONCLUSION: Even if the results of using HLA identical unrelated donor marrow are encouraging, the high transplantation related mortality due to infection and GVHD is a major challenge. It is not likely that this technique will be extensively used. However, in cases of high risk acute leukemia or chronic myelogenous leukemia without appropriate related donor, URD-BMT might be a therapeutic measure.