Postoperative venous thromboembolism after surgery for locally recurrent rectal cancer.

BACKGROUND: Local recurrence is common after curative resections of rectal cancer. Surgical resection is considered a primary curative treatment option for patients with locally recurrent rectal cancer (LRRC). LRRC often requires a combined resection of other organs, especially in the case of posterior recurrence, which requires a combined resection of the sacrum, making the surgery highly invasive. Venous thromboembolism (VTE) is one of the lethal complications in the postoperative period, particularly in the field of pelvic surgery. We found no reports regarding the risks of postoperative VTE in surgery for LRRC, a typical highly invasive procedure in the field of colorectal surgery. This study aims to evaluate the risk of postoperative VTE in surgery for LRRC patients. METHODS: From April 2010 to March 2022, a total of 166 patients underwent surgery for LRRC in the pelvic region at our institutions. Clinicopathological background and VTE incidence were compared retrospectively. RESULTS: Among the 166 patients included in the study, 55 patients (33.1%) needed sacral resection. Pharmacological prophylaxis for prevention of VTE was performed in 121 patients (73.3%), and the incidence of VTE was 9.09% (5/55 patients) among those who underwent surgery for LRRC with sacral resection, while it was 1.8% (2/111 patients) in those without sacral resection. In univariate analysis, the combination with sacral resection was identified as a risk factor for VTE in surgery for LRRC (p = 0.047). CONCLUSIONS: This study demonstrates that surgery for LRRC combined with sacral resection could be a significant risk factor for VTE.

Currarino syndrome with immature teratoma: A case report with review of literature.

ABSTRACT: Currarino syndrome (CS) is a rare congenital syndrome characterized by a triad of anorectal malformation, sacral deformity, and presacral mass. In about 50% of cases, it is caused by HLXB9 gene mutation in chromosome 7q36. A 13-month-male child presented with presacral discharging sinus with a history of surgery for anorectal malformation and perineal fistula at the time of birth. On detailed investigation, the child revealed to have anal atresia, hemisacrum, and presacral mass. Histopathology of presacral mass showed features of immature teratoma. The presacral mass in CS is mostly an anterior myelomeningocele or presacral teratoma. The development of immature teratoma in presacral mass is very rare. The histopathological identification of immature component of teratoma in the presacral mass of CS is important for risk stratification and further management. Suspicion of CS should be raised in any child presenting with partial phenotype of the triad.

Clinical study on freehand of bicortical sacral screw fixation with the assistance of torque measurement device.

BACKGROUND: Sacral screw loosening is a typical complication after internal fixation surgery through the vertebral arch system. Bicortical fixation can successfully prevent screw loosening, and how improving the rate of bicortical fixation is a challenging clinical investigation. OBJECTIVE: To investigate the feasibility of improving the double corticality of sacral screws and the optimal fixation depth to achieve double cortical fixation by combining the torque measurement method with bare hands. METHODS: Ninety-seven cases of posterior lumbar internal fixation with pedicle root system were included in this study. Based on the tactile feedback of the surgeon indicating the expected penetration of the screw into the contralateral cortex of the sacrum, the screws were further rotated by 180°, 360°, or 720°, categorized into the bicortical 180° group, bicortical 360° group, and bicortical 720° group, respectively. Intraoperatively, the torque during screw insertion was recorded. Postoperatively, the rate of double-cortex engagement was evaluated at 7 days, and screw loosening was assessed at 1 year follow-up. RESULTS: The bicortical rates of the 180° group, 360° group, and 720° group were 66.13%, 91.18% and 93.75%, respectively. There were statistically significant differences between the 180° group and both the 360° and 720° groups (P < 0.05). However, there was no statistically significant difference between the 360° group and the 720° group (P > 0.05).The rates of loosening of sacral screws in the 180° group, 360° group, and 720° group were 20.97%, 7.35% and 7.81%, respectively. There were statistically significant differences between the 180° group and both the 360° and 720° groups (P < 0.05). However, there was no statistically significant difference between the 360° group and the 720° group (P > 0.05). The bicortical 360° group achieved a relatively satisfactory rate of dual cortical purchase while maintaining a lower rate of screw loosening. CONCLUSION: Manual insertion of sacral screws with the assistance of a torque measurement device can achieve a relatively satisfactory dual cortical purchase rate while reducing patient hospitalization costs.

Feasibility of transperineal minimal invasive surgery when performing sacrectomy for advanced primary and recurrent pelvic malignancies.

BACKGROUND: This study aimed to clarify the efficacy and safety of minimally invasive transabdominal surgery (MIS) with transperineal minimal invasive surgery (tpMIS) for sacrectomy in advanced primary and recurrent pelvic malignancies. METHODS: Using a prospectively collected database, we retrospectively analyzed the clinical, surgical, and pathological outcomes of MIS with tpMIS for sacrectomies. Surgery was performed between February 2019 and May 2023. The median follow-up period was 27 months (5-46 months). RESULTS: Fifteen consecutive patients were included in this analysis. The diagnoses were as follows: recurrent rectal cancer, n = 11 (73%); primary rectal cancer, n = 3 (20%); and recurrent ovarian cancer, n = 1 (7%). Seven patients (47%) underwent pelvic exenteration with sacrectomy, six patients (40%) underwent abdominoperineal resection (APR) with sacrectomy, and two patients (13%) underwent tumor resection with sacrectomy. The median intraoperative blood loss was 235 ml (range 45-1320 ml). The postoperative complications (Clavien-Dindo grade ≥ 3a) were graded as follows: 3a, n = 6 (40%); 3b, n = 1 (7%); and ≥ 4, n = 0 (0%). Pathological examinations demonstrated that R0 was achieved in 13 patients (87%). During the follow-up period, two patients (13%) developed local re-recurrence due to recurrent cancer. The remaining 13 patients (87%) had no local disease. Fourteen patients (93%) survived. CONCLUSIONS: Although the patient cohort in this study is heterogeneous, MIS with tpMIS was associated with a very small amount of blood loss, a low incidence of severe postoperative complications, and an acceptable R0 resection rate. Further studies are needed to clarify the long-term oncological feasibility.

The effect of preoperative embolization on giant cell tumors of the bone localized in the iliosacral region of the pelvis.

INTRODUCTION: Giant cell tumors of the bone (GCTB) are aggressive neoplasms, with rare occurrences in the posterior pelvis and sacral area. Surgical challenges in this region include the inability to apply a tourniquet and limited cementation post-curettage due to proximity to neurovascular structures, leading to potential complications. This case-control study explores the impact of preoperative embolization on GCTB located in the iliosacral region. METHODS: Five surgeries (January-December 2021) for pelvic GCTB (3 sacrum, 2 posterior ilium) were performed on four patients. Diagnosis was confirmed through preoperative CT-guided biopsies. One surgery involved curettage with PMMA cement filling, while four surgeries had curettage without cavity filling. Preoperative embolization of the tumor feeding vessel occurred approximately 16 h before surgery in two cases. Denosumab treatment was not administered. RESULTS: Tumor volume, assessed by preoperative MRI, was comparable between patients with and without preoperative embolization (p = .14). Surgeries without embolization had a mean intraoperative blood loss of 3250 ml, erythrocyte transfusion volume of 1125 ml, and a mean surgical time of 114.5 min for two surgeries. Surgeries with preoperative embolization showed a mean intraoperative blood loss of 1850 ml, no erythrocyte transfusion requirement, and a mean surgical time of 68 min. CONCLUSION: Curettage of GCTB in the posterior pelvis and sacrum presents challenges, with significant intraoperative blood loss impacting surgical time and transfusion needs. Preoperative embolization may be beneficial in reducing blood loss during surgery in these cases.

Triangular spinopelvic fixation for U-shaped sacral fractures and tile C pelvic disruptions: counter-nutation (anteflexion and rotation) load-bearing instability requires complementary anterior pelvic ring fixation.

Unstable trauma lesion of the spinopelvic junction, including U-shaped sacral fractures and Tile C pelvic ring disruptions, require surgical stabilization in order to realign the bone arches of the pelvis thus reducing the upcoming orthopaedic impairment during sitting, standing, and walking positions, decompress the nerves roots of the cauda equina in a view of reducing neurological impairment, and allow early weight bearing. Even though posterior open modified triangular spinopelvic fixation is particularly efficient for treating unstable trauma lesions of the spinopelvic junction, it may not be sufficient alone in order to prevent long-term counter-nutation, i.e. rotation and anteflexion deformity of the anterior pelvis under load bearing conditions. Such progressive deformation is caused by either the slight rotation of the iliac connectors within the head of iliac screws for spinopelvic constructs, or the slight rotation of sacral cancellous bone around transsacral screws in case of percutaneous procedure. Regardless of the posterior surgical technique that is used, complementary anterior pelvic fixation appears mandatory in order to prevent such deformation over time, which can lead to pelvic asymmetry and then gait imbalance.

Insertion sites of iliosacral screws on the posterior ilium: Implications for posterior pelvic fixation.

OBJECTIVES: Lateral compression type II pelvic ring injuries can be treated with fixation through open or percutaneous approaches depending on the injury pattern and available osseous fixation pathways. The start site of iliosacral screws to stabilize these injuries should be on the unstable posterior iliac fragment; however, our understanding of start sites for iliosacral screws has not been developed. The purpose of this study is to provide an analysis of iliosacral screw start sites on the posterior ilium to help guide treatment of pelvic ring injuries. METHODS: One-hundred and seventeen consecutive patients at an academic level I trauma center with pelvic ring injuries who underwent surgical treatment with iliosacral screws were included in the final analysis. The start sites of iliosacral screws with confirmed intraosseous placement on a postoperative computed tomography were mapped on the posterior ilium and analyzed according to the sacral segment and type of iliosacral screw. RESULTS: One-hundred and seventeen patients were included in the final analysis. Of the total of 272 iliosacral screw insertion sites analyzed, 145 (53%) were sacroiliac-style screws and 127 (47%) were transsacral screws. The insertion sites for sacroiliac-style screws and transsacral screws at different sacral segment levels can vary but have predictable regions on the posterior ilium relative to reliable osseous landmarks. CONCLUSIONS: Iliosacral screws start sites on the posterior ilium have reliable regions that can be used to plan posterior fixation of pelvic ring injuries.

High Rate of Concomitant Lumbo-Sacral Spine Pathology in the Setting of Hip Abductor Tendon Repair.

BACKGROUND: Hip abductor deficiency is a common cause of lateral hip pain in middle-aged patients. Identifying upstream muscle denervation originating in the lumbo-sacral spine could potentially impact the management of patients who have abductor deficiency. The purpose of this study was to estimate the prevalence of lumbo-sacral pathology (L4 to S1) in patients undergoing hip abductor tendon repair. METHODS: All cases of primary hip abductor repair performed at a tertiary care center between January 2010 and December 2021 were reviewed. Patients were classified into the following groups: A) confirmed L4 to S1 disease based on preoperative or perioperative L4 to S1 interventions (ie, surgery, epidural injections, and/or positive electromyography findings); B) radiographic evidence on lumbar spine magnetic resonance imaging demonstrating nerve compression at L4 to S1; and C) no evidence of L4 to S1 disease. RESULTS: There were 131 cases of primary hip abductor repair that were included. Over 80% of patients were women, who had a mean age of 64 years (range, 20 to 85). There were thirteen patients (9.9%) who underwent concomitant total hip arthroplasty (THA). Of the included patients, 29% (n = 38) were categorized into group A, 12% (n = 16) into group B, and 59% (n = 77) into group C. Patients who had L4 to S1 pathology were older than patients who did not have L4 to S1 pathology (67 versus 61 years, P = .004). Of the patients undergoing concomitant THA and hip abductor repair, 54% demonstrated evidence of lumbo-sacral spine pathology. CONCLUSIONS: Over 40% of patients undergoing isolated hip abductor tendon repair and >50% of patients undergoing concomitant hip abductor tendon repair and THA demonstrated evidence of L4 to S1 disease perioperatively. Patients demonstrating symptomatic hip abductor deficiency should be screened for concomitant lower lumbo-sacral spine pathology.

Effect of different lumbar-iliac fixation and sacral slope for Tile C1.3 pelvic fractures: a biomechanical study.

BACKGROUND: Lumbar-iliac fixation (LIF) is a common treatment for Tile C1.3 pelvic fractures, but different techniques, including L4-L5/L5 unilateral LIF (L4-L5/L5 ULIF), bilateral LIF (BLIF), and L4-L5/L5 triangular osteosynthesis (L4-L5/L5 TOS), still lack biomechanical evaluation. The sacral slope (SS) is key to the vertical shear of the sacrum but has not been investigated for its biomechanical role in lumbar-iliac fixation. The aim of this study is to evaluate the biomechanical effects of different LIF and SS on Tile C1.3 pelvic fracture under two-legged standing load in human cadavers. METHODS: Eight male fresh-frozen human lumbar-pelvic specimens were used in this study. Compressive force of 500 N was applied to the L4 vertebrae in the two-legged standing position of the pelvis. The Tile C1.3 pelvic fracture was prepared, and the posterior pelvic ring was fixed with L5 ULIF, L4-L5 ULIF, L5 TOS, L4-L5 TOS, and L4-L5 BLIF, respectively. Displacement and rotation of the anterior S1 foramen at 30° and 40° sacral slope (SS) were analyzed. RESULTS: The displacement of L4-L5/L5 TOS in the left-right and vertical direction, total displacement, and rotation in lateral bending decreased significantly, which is more pronounced at 40° SS. The difference in stability between L4-L5 and L5 ULIF was not significant. BLIF significantly limited left-right displacement. The ULIF vertical displacement at 40° SS was significantly higher than that at 30° SS. CONCLUSIONS: This study developed an in vitro two-legged standing pelvic model and demonstrated that TOS enhanced pelvic stability in the coronal plane and cephalad-caudal direction, and BLIF enhanced stability in the left-right direction. L4-L5 ULIF did not further improve the immediate stability, whereas TOS is required to increase the vertical stability at greater SS.

Short-term outcomes of single port robotic hysterectomy with concomitant sacrocolpopexy.

The Da Vinci single port® (SP) robotic platform heralds a new era of minimally invasive surgery (MIS). The primary objective of this study was to assess short-term outcomes in patients undergoing SP robotic hysterectomy with concomitant sacrocolpopexy for pelvic organ prolapse (POP). We performed a retrospective case series at two tertiary care centers between January 2021 and August 2023. Patients with POP electing to undergo SP robotic hysterectomy with concomitant sacrocolpopexy were included. Chart abstraction was used to collect patient demographics and clinical outcomes. Recurrent POP was defined as new bothersome vaginal bulge symptoms and evidence of POP beyond the hymen on postoperative examination. 69 patients were included. Median operative time was 209 min (135-312) and estimated blood loss was 100 mL (20-2000). 1 (1.4%) patient sustained a major vascular injury resulting in laparotomy. Median pain score and morphine equivalents administered in PACU were low at 3 (0-7) and 3.2 (0-27) respectively. At 3 months, 60 (86.9%) patients were seen either in person or via telemedicine for their follow up appointment. 59/60 (98.3%) reported no vaginal bulge symptoms and 50/51 (98.0%) had stage 0 or 1 prolapse on exam. One (1.4%) patient had recurrent prolapse and underwent an additional repair. Postoperative complications included 2 (2.9%) cases of ileus/small bowel obstruction, 1 (1.4%) pelvic hematoma requiring a blood transfusion, and 1 (1.4%) umbilical hernia. The SP robotic platform is a safe and feasible platform for MIS hysterectomy and sacrocolpopexy with good short term anatomic and symptomatic outcomes.

Fluoroscopy guided teardrop technique for open trans-muscular iliac screw placement and open reduction maneuvers during modified triangular spinopelvic fixation for unstable U-shaped sacral and tile C pelvic traumas: technical note.

Unstable traumas of the spinopelvic junction, which include displaced U-shaped sacral fractures (Roy-Camille type 2 and type 3) and Tile C vertical shear pelvic ring disruptions, occur in severe traumas patients following high speed traffic accident or fall from a height. These unstable traumas of the spinopelvic junction jeopardize one's ability to stand and to walk by disrupting the biomechanical arches of the pelvis, and may also cause cauda equina syndrome. Historically, such patients were treated with bed rest and could suffer a life-long burden of orthopedic and neurological disability. Since Schildhauer pioneer work back in 2003, triangular spinopelvic fixation, whether it is performed in a percutaneous fashion or by open reduction and internal fixation, allows to realign bone fragments of the spinopelvic junction and to resume walking within three weeks. Nevertheless, such procedure remains highly technical and it not encountered very often, even for spine surgeons working in high-volume level 1 trauma centers. Hence, this visual technical note aims to provide a few tips to guide less experience surgeons to complete this procedure safely.

The optimal introversion angle and length of pedicle screw to avoid L1-S1 vascular damage.

BACKGROUND: posterior pedicle screw fixation is common method, one of the most severe complications is iatrogenic vascular damage, no report investigated association of different introversion angles (INTAs) and length of pedicle screw. The aims were to investigate the optimal introversion angle and length of pedicle screw for improving the safety of the operation, and to analyze the differences of vascular damage types at L1-S1. METHODS: Lumbar CT imaging data from110 patients were analyzed by DICOM software, and all parameters were measured by new Cartesian coordinate system, INTAs (L1-L5:5°,10°,15°,S1: 0°, 5°,10°,15°), DO-AVC (the distance between the origin (O) with anterior vertebral cortex (AVC)), DAVC-PGVs (the distance between AVC and the prevertebral great vessels (PGVs)), DO-PGVs (the distance between the O and PGVs). At different INTAs, DAVC-PGVs were divided into four grades: Grade III: DAVC-PGVs ≤ 3 mm, Grade II: 3 mm < DAVC-PGVs ≤ 5 mm, Grade I: DAVC-PGVs > 5 mm, and N: the not touching PGVs. RESULTS: The optimal INTA was 5° at L1-L3, the left was 5° and the right was 15° at L4, and screw length was less than 50 mm at L1-L4. At L5, the left optimal INTA was 5° and the right was 10°, and screw length was less than 45 mm. The optimal INTA was 15° at S1, and screw length was less than 50 mm. However, screw length was less than 40 mm when the INTA was 0° or 5° at S1. CONCLUSIONS: At L5-S1, the risk of vascular injury is the highest. INTA and length of the pedicle screw in lumbar operation are closely related. 3 mm interval of screw length may be more preferable to reduce vascular damage.

Transforaminal Endoscopic Lumbar Foraminotomy for the Treatment of L5-S1 Isthmic Lumbar Spondylolisthesis with Foraminal Stenosis: A 1-Year Follow-Up.

BACKGROUND: Isthmic lumbar spondylolisthesis (ILS) is a prevalent spinal pathology. Radicular pain in patients is often attributed to L5-S1 ILS combined with foraminal stenosis (FS), making such patients prime candidates for surgical intervention. We herein aimed to elucidate the surgical technique and clinical outcomes of transforaminal endoscopic lumbar foraminotomy (TELF) in the treatment of L5-S1 ILS with FS. METHODS: From September 2021 to December 2022, 20 consecutive patients were diagnosed with L5-S1 ILS with FS and underwent TELF. All patients were followed up for at least 12 months. The clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index, and modified MacNab criteria. RESULTS: The mean age of the patients was 62.4 ± 10.9 years. The mean preoperative VAS score for low back, VAS score of the leg, and Oswestry Disability Index score was 5.1 ± 1.7, 7.4 ± 0.7, and 58.0 ± 8.4, respectively. These scores significantly improved to 1.8 ± 0.7, 1.5 ± 0.6, and 15.3 ± 7.1 at 12 months postoperatively, respectively (P < 0.01). Evaluation based on the modified MacNab criteria revealed that 95.0% of patients achieved a good-to-excellent outcome. One patient underwent revision surgery. CONCLUSIONS: TELF emerges as a potentially safe and effective surgical option for alleviating radicular pain in patients with L5-S1 stable ILS combined with FS. While our short-term clinical results are satisfactory, it is necessary to expand the sample size and extend the follow-up time to validate the effectiveness and long-term efficacy of TELF.

Reciprocal Changes in Sagittal Spinal Alignment After L5-S1 Anterior Lumbar Interbody Fusion.

OBJECTIVE: Degenerative diseases of the lumbar spine decrease lumbar lordosis (LL). Anterior lumbar interbody fusion (ALIF) at the L5-S1 disc space improves segmental lordosis, LL, and sagittal balance. This study investigated reciprocal changes in spinopelvic alignment after L5-S1 ALIF. METHODS: A retrospective chart review identified patients who underwent L5-S1 ALIF with or without posterior fixation at a single institution (November 1, 2016 to October 1, 2021). Changes in pelvic tilt, sacral slope, proximal LL (L1-L4), distal LL (L4-S1), total LL (L1-S1), segmental lordosis, pelvic incidence-LL mismatch, thoracic kyphosis, cervical lordosis, and sagittal vertical axis were measured on preoperative and postoperative radiographs. RESULTS: Forty-eight patients were identified. Immediate postoperative radiographs were obtained at a mean (SD) of 17 (20) days after surgery; delayed radiographs were obtained 184 (82) days after surgery. After surgery, patients had significantly decreased pelvic tilt (15.71° [7.25°] vs. 17.52° [7.67°], P = 0.003) and proximal LL (11.86° [10.67°] vs. 16.03° [10.45°], P < 0.001) and increased sacral slope (39.49° [9.27°] vs. 36.31° [10.39°], P < 0.001), LL (55.35° [13.15°] vs. 51.63° [13.38°], P = 0.001), and distal LL (43.17° [9.33°] vs. 35.80° [8.02°], P < 0.001). Segmental lordosis increased significantly at L5-S1 and decreased significantly at L2-3, L3-4, and L4-5. Lordosis distribution index increased from 72.55 (19.53) to 81.38 (22.83) (P < 0.001). CONCLUSIONS: L5-S1 ALIF was associated with increased L5-S1 segmental lordosis accompanied by pelvic anteversion and a reciprocal decrease in proximal LL. These changes may represent a reversal of compensatory mechanisms, suggesting an overall relaxation of spinopelvic alignment after L5-S1 ALIF.

Treatment Outcomes of Lower Urinary Tract Symptoms due to Fragility Sacral Fractures: A Review of Eight Patients and Literature.

BACKGROUND: Sacral fractures can cause lower urinary tract symptoms (LUTS) due to damage to the cauda equina. While several studies have reported on sacral fractures due to high-energy trauma, those due to fragility fractures have only been reported in case reports and their clinical differences are not well known. This study aimed to investigate the clinical characteristics of LUTS caused by fragility sacral fractures and propose a novel treatment strategy. METHODS: This study is retrospective, uncontrolled, clinical case series. The inclusion criteria were sole sacral fractures due to low-energy trauma and appearance of LUTS after injury. Patients with additional spinal fractures or combined abdominal or pelvic organ injuries that could cause LUTS were excluded. Improvement in LUTS, period from onset to improvement, and imaging findings were recorded. RESULTS: Eight patients met the inclusion criteria (4 surgical and 4 conservative treatment cases). Six patients showed improvement in LUTS. In surgical cases, the mean period from onset of LUTS to surgery and from onset of LUTS to improvement was 14.5 and 21.5 days, respectively. Intraoperative rupture or laceration of the dural sac was not observed. In 2 conservatively improved cases, the period from onset to improvement of LUTS was 14 and 17 days. CONCLUSIONS: LUTS can improve even with conservative treatment and should be utilized as the primary choice. LUTS caused by severe sacral canal deformity and stenosis can be reversible, and the decision to perform surgical treatment is still timely if LUTS do not improve with conservative treatment for several weeks.

Pedicled omental flaps for complex wound reconstruction following surgery for primary spine tumors of the mobile spine and sacrum.

OBJECTIVE: Surgery for primary tumors of the mobile spine and sacrum often requires complex reconstruction techniques to cover soft-tissue defects and to treat wound and CSF-related complications. The anatomical, vascular, and immunoregulatory characteristics of the omentum make it an excellent local substrate for the management of radiation soft-tissue injury, infection, and extensive wound defects. This study describes the authors' experience in complex wound reconstruction using pedicled omental flaps to cover defects in surgery for mobile spine and sacral primary tumors. METHODS: A retrospective cohort analysis was conducted on 34 patients who underwent pedicled omental flap reconstruction after en bloc resection of primary sacral and mobile spine tumors between 2010 and 2020. The study focused on assessing the indications for omental flap usage, including soft-tissue coverage, protection against postoperative radiation therapy, infection management, vascular supply for bone grafts, and dural defect and CSF leak repair. Patient demographic characteristics, tumor characteristics, surgical outcomes, and follow-up data were analyzed to determine the procedure's efficacy and complication rates. RESULTS: From 2010 to 2020, 34 patients underwent pedicled omental flap reconstruction after en bloc resection of sacral (24 of 34 [71%]) and mobile spine (10 of 34 [29%]) primary tumors, mostly chordomas. The patient cohort included 21 men and 13 women with a median (range) age of 60 (32-89) years. The most common indication for omental flap was soft-tissue coverage (20 of 34 [59%]). Other indications included protecting abdominopelvic organs for postoperative radiation therapy (6 of 34 [18%]), treating infections (5 of 34 [15%]), providing vascular supply for free fibular bone graft (1 of 34 [3%]), and repairing large dural defects and CSF leak (2 of 34 [6%]). The median (range) follow-up was 24 (0-132) months, during which 71% (24 of 34) of patients did not require additional surgery for wound-related complications. At last follow-up, 59% (20 of 34) had stable disease and 32% (11 of 34) had recurrence, had progression of disease, or had been discharged to hospice after treatment. CONCLUSIONS: The pedicled omentum is an effective local tissue graft that can be used for complex wound reconstruction and management of high-risk closures in primary spine tumors. This technique may have a lower rate of complications than other approaches and may influence surgical planning and flap selection in challenging cases.

Do expandable cage size and number of cages matter in transforaminal lumbar interbody fusion at L5-S1? A comparative biomechanical analysis using finite element modeling.

OBJECTIVE: Expandable transforaminal lumbar interbody fusion (TLIF) cages were designed to address the limitations of static cages. Bilateral cage insertion can potentially enhance stability, fusion rates, and segmental lordosis. However, the benefits of unilateral versus bilateral expandable cages with varying sizes in TLIF remain unclear. This study used a validated finite element spine model to compare the biomechanical properties of L5-S1 TLIF by using differently sized expandable cages inserted unilaterally or bilaterally. METHODS: A finite element model of X-PAC expandable lumbar cages was created and used at the L5-S1 level. This model had cage dimensions of 9 mm in height, 15° in lordosis, and varying widths and lengths. Various placements (unilateral vs bilateral) and sizes were examined under pure moment loading to evaluate range of motion, adjacent-segment motion, and endplate stress. RESULTS: Stability at the L5-S1 level decreased when smaller cages were used in both the unilateral and bilateral cage models. In the unilateral model, cage 1 (the smallest cage) resulted in 47.9% more motion at the L5-S1 level compared to cage 5 (the largest cage) in flexion, as well as 64.8% more motion in extension. Similarly, in the bilateral TLIF model, bilateral cage 1 led to 49.4% more motion at the L5-S1 level in flexion and 73.4% more motion in extension compared to bilateral cage 5. Unilateral insertion of cage 5 provided superior stability in flexion and surpassed cages 1-3 in extension when compared to cages inserted either unilaterally or bilaterally. Reduced motion at L5-S1 correlated with increased adjacent-segment motion at L4-5. Bilateral TLIF resulted in greater adjacent-segment motion compared to unilateral TLIF with the same-size cages. Inferior endplates experienced higher stress during flexion and extension than superior endplates, with this difference being more pronounced in the bilateral model. In bilateral cage placement, stress differences ranged from 46.3% to 60.0%, while they ranged from 1.1% to 9.6% in unilateral cages. Qualitative analysis revealed increased focal stress in unilateral cages versus bilateral cages. CONCLUSIONS: The authors' study shows that using a large unilateral TLIF cage may offer better stability than the bilateral insertion of smaller cages. While large bilateral cages increase adjacent-segment motion, they also provide a uniform stress distribution on the endplates. These findings deepen our understanding of the biomechanics of the available expandable TLIF cages.

En-bloc excision of sacral squamous cell carcinoma with immediate reconstruction.

Sacral squamous cell carcinoma is an uncommon condition that may arise in scars following burns or in chronic wounds, such as an untreated pilonidal cyst. The aim of the present technical note is to describe a surgical technique aimed at minimizing local recurrence rates by en-bloc resection as well as providing immediate plastic reconstruction: 1. right-sided extended vertical rectus abdominis myo-cutaneous (VRAM) flap; 2. abdomino-perineal excision of the rectum with end colostomy; 3. en-bloc excision of the mass inclusive of gluteus maximus muscles and distal sacrectomy; 4. sacrectomy defect covered with VRAM flap; 5. bilateral gluteal defects covered with single-layer dermal substitute of bovine collagen and elastin hydrolysate followed by immediate split-thickness skin grafting from bilateral thigh donor sites, and negative pressure wound therapy dressings. This approach resulted in a favorable outcome at 2-year follow-up in a male patient presenting with a large locally advanced sacral squamous cell carcinoma involving the external anal sphincter muscle.