Iliosacral Bone Tumor Resection Using Cannulated Screw-Guided Gigli Saw - A Novel Technique

Background Adequate margins are technically difficult to achieve for malignant tumors involving the sacroiliac joint due to limited accessibility and viewing window. In order to address the technical difficulties faced in iliosacral tumor resection, we proposed a technique for precise osteotomy, which involved the use of canulated screws and Gigli saw (CSGS) that facilitated directional control, anteroposterior linkage of resection points and adequate surgical margins. The purpose of the current study was to evaluate whether CSGS technique facilitated sagittal osteotomy at sacral side, and were adequate surgical margins achieved? Also functional and oncological outcomes was determined along with the noteworthy complications. Methods From April 2018 to November 2019, we retrospectively reviewed 15 patients who underwent resections for primary tumors of pelvis or sacrum necessitating iliosacral joint removal using the proposed CSGS technique. Chondrosarcoma was the most common diagnosis. The osteotomy site within sacrum was at ipsilateral ventral sacral foramina in 8 cases, midline of sacrum in 5 cases, and contralateral ventral sacral foramina and sacral ala with 1 case each. The average intraoperative blood loss was 3640 mL (range, 1200 and 6000 mL) with a mean operation duration of 7.4 hours (range, 5 to 12 hours). The mean follow-up was 23.0 months (range, 18 and 39 months) for alive patients. Results Surgical margins were wide in 12 patients (80%), wide-contaminated in 1 patient (6.7%), and marginal in 2 patients (13.3%). R0 resection was achieved in 12 (80%) patients and R1 resection in 3 patients. There were three local recurrences (20%) occurred at a mean time of 11 months postoperatively. No local recurrence was observed at sacral osteotomy. The overall one-year and three-year survival rate was 86.7% and 72.7% respectively.Complications occurred in three patients. Conclusions The current study demonstrated that CSGS technique for tumor resection within the sacrum and pelvis was feasible and can achieve ideal resection accuracies. The use of CSGS was associated with high likelihood of negative margin resections in the current series. Intraoperative use of CSGS appeared to be technically straightforward and allowed achievement of planned surgical margins. It is worthwhile to consider the use of CSGS technique in resection of pelvic tumors with sacral invasion and iliosacral tumors, however further follow-up at mid to long-term is warranted to observe local recurrence rate.

Intrapelvic entrapment of sacral nerve roots by abnormal bundles of the piriformis muscle: description of an extra-spinal cause of sciatica and pudendal neuralgia

Piriformis syndrome is a well-known extra-spinal cause of sciatica characterized by the entrapment of the sciatic nerve by variant bundles of the piriformis muscles in the deep gluteal space. In this case series, we describe the entrapment of intrapelvic portions of the sacral nerve roots by a variant bundle of the piriformis muscle originating medially to the sacral foramina, the surgical technique for the laparoscopic treatment of this condition, and the outcomes of the first eight cases treated with this technique. Five female and three male patients presenting with sciatica, pudendal pain and lower urinary tract symptoms underwent a laparoscopic exploration of the intrapelvic portion of the sacral nerve roots and transection of the abnormal piriformis bundle. Surgical technique is demonstrated in the Supplementary Video. Clinical success was achieved in seven of the eight patients, with a reduction of pain numeric rating scale from 8.5 (±1.2; 7–10) pre-operatively to 2.1 (±2.6; 0–7), 1-year following surgery. In conclusion, entrapment of intrapelvic portions of the sacral nerve roots by variant bundles of the piriformis originating medially to the sacral foramina are an extraspinal cause of sciatica, which can be treated though a laparoscopic approach.

Management of presacral retroperitoneal schwannoma: highlighting the various features

Schwannomas are relatively rare tumours. They occur in approximately 1 of 40,000 hospital admissions. Usually asymptomatic unless very big in size. They may present with symptoms of visceral compression viz. constipation, urinary frequency and urgency, or the nerve compression like sciatica, lower extremity weakness, tingling and numbness. We here highlight the various clinical, radiological and pathologic features the tumour and importance of proper pre-operative imaging, planning regarding surgery and the type of consent required before the surgery in a 30 years old male with a large pelvic mass, diagnosed and supposed to be Schwannoma arising from the S2 sacral foramina. We were able to enucleate the mass intact without any visceral or neuro-vascular injury with minimal blood loss.

A simple approach for ultrasound-guided pararadicular injections in the sacral spine: a pilot computer tomography controlled cadaver study

Aims: Injection therapies play an increasingly decisive role in the treatment of lower back pain. Cumulative studies could show the benefits of ultrasound-guided instillation procedures in the cervical and lumbar spine. We conducted this study to provide a new simple sonographic approach for pararadicular injections of the sacral spinal nerves and to prove the feasibility and accuracy by means of CT and anatomic dissection.Material and methods: Eight ultrasound-guided injections at four different levels of the sacral spine on a human ethanol-glycerol–embalmed cadaver (S1-S4) were performed. By means of sonography the sacral foramina were identified and the spinal needles were advanced in “in-plane technique” to the medial margin of the respective sacral foramen. Subsequently a solution of blue dye and contrast agent were injected. Then CT scans and anatomic dissection of the cadaver were performed to verify the correct placement of the needle tips and to visualize the dispersion of the injected solution in the respective compartment.Results: Altogether a 100% success rate for a correct injection could be achieved. CT examination confirmed the correct placement of every needle tip within the intended compartment. Also, the anatomic dissections affirmed the appropriate needle positioning. Moreover, the blue dye dispersion was seen in the correct compartments and around the targeted spinal nerves.Conclusions: Although this study was only performed on cadaveric models, this new sonographic approach for pararadicular injections in the sacral spine allows an easy, precise and unerring needle placement within the dorsal sacral foramen.

Usefulness of Sacral Sublaminar Wire for Low Transverse Sacral Fractures: Two Cases’ Report

Low transverse sacral fractures are rare, with only two published reports regarding their surgery. The complication associated with surgery for sacral fractures is the prominence of implants. In addition, screw fixation below S3 is impractical. We performed posterior sacral fixation using S2 alar iliac (S2AI) screws and sacral sublaminar wires for low transverse sacral fractures. Case 1 was 65-year-old male with an S2-3 transverse sacral fracture. We performed laminectomy (S2-3) and passed ultrahigh molecular weight polyethylene (UHMWPE) cables from laminectomy area to the third posterior sacral foramina. We inserted S2AI screws and connected rods. We also tightened the UHMWPE cables. The implants did not protrude into skin. One year after surgery, the sacral fracture healed without any displacement. Case 2 was a 42-year-old female with an S2 transverse sacral fracture. We performed laminectomy (S1–3) and passed UHMWPE cables from laminectomy area to the third and fourth posterior sacral foramina. We inserted S1 pedicular screws and S2AI screws and connected rods. We also tightened UHMWPE cables. The implants did not protrude into skin. One year after surgery, the sacral fracture healed without any displacement. We consider sacral sublaminar wires to be useful bone anchors in lower sacrum.

VARIABILITIES IN ANATOMICAL ARRANGEMENT OF SACRAL PLEXUS ROOTS. VARIACIONES EN LA DISPOSICIÓN ANATÓMICA DE LAS RAÍCES DEL PLEXO SACRO

Introducción. Las ramas del plexo sacro juegan un rol importante en la inervación motora y sensitiva del miembro inferior. En operaciones de la médula espinal observamos diversas variedades y nos motivó para iniciar este estudio dirigido a determinar la formación del plexo sacro desde la emergencia de cada raíz en los agujeros sacros hasta la formación de sus ramas terminales. Material y método. Se examinaron 100 plexos sacros en 50 cadáveres adultos con el propósito de determinar incidencia de las variaciones nerviosas. También consideramos el recorrido de sus ramas, sus anastomosis y grosor. Destacamos las particularidades de la inervación motora en el diagnóstico, además de la complejidad y variaciones anatómicas. Resultados. En general observamos 3 raíces sacras con la participación de S4 y el tronco lumbo-sacro de L4 y L5, y 4 nervios sacros. Habitualmente se observó un recorrido ascendente doble de la raíz S1, mientras que para las otras raíces la emergencia doble no fue común. El tronco lumbosacro se engrosó en 19 casos. La división muy alta del nervio ciático (en la pelvis menor) se observó en 2 casos. El nivel de ramificación de los otros nervios dependió del tipo de plexo. Conclusión. Nuestro estudio reveló variaciones relativamente frecuentes y variaciones anatómicas extraordinarias en la formación de las raíces nerviosas y la ramificación del plexo sacro. El conocimiento detallado de estas variaciones es útil para el propio diagnóstico y el tratamiento quirúrgico de las lesiones del plexo sacro y el dolor idiopático. Introduction. Branches of sacral plexus play an important role in the motor and sensory innervation of the lower limb. Various variations observed during the spinal operations have motivated us to start the study aimed on determination of the sacral plexus formation from its exit of particular roots from sacral foramina up to their formation into terminal branches. Material and method. One hundred sacral plexuses have been examined on 50 adult cadavers for a purpose to find out an incidence of its neural variations. We have considered also the course of their branches, the anatomoses and their thickness. We highlighted the motor innervation particularities in the relation to the diagnosis besides its anatomical complexity and variability. Results. Commonly were observed 3 sacral roots with the share of S4 and lumbosacral trunk of L4 and L5 and 4 sacral nerves. Doubled ascending course of S1 root was often observed, by the other sacral roots the doubled exit was not so frequent. Lumbosacral trunk was thickened in 19 cases. Very high division of the sciatic nerve (in the lesser pelvis) was observed in 2 cases. The branching off level of other nerves depended on the plexus type. Conclusion. Our study revealed a relatively frequent variabilities and described some extraordinary anatomical variations in the formation of nerve roots and branches of the sacral plexus. The detailed knowledge of these variabilities is useful for the proper diagnostics and surgical treatment of the sacral plexus injuries and unexplainable paient‘s complaints.

Ct Evaluation of Acupuncture Needles Inserted into Sacral Foramina

Objective To use CT scanning to evaluate the precision with which acupuncture needles can be inserted into sacral foramina to establish sacral nerve modulation by electroacupuncture. Methods The subjects were five adult women (mean age 71.6 years). These five cases were divided into two groups. In the first three subjects (group A) the intention was to insert acupuncture needles in the S3 and S4 foramina; in the remaining two subjects (group B) the intention was to insert acupuncture needles in the S2 and S3 foramina. Results CT scanning showed that in subject 1 of group A, the acupuncture needle intended for insertion in S3 was actually in the S4 foramen, and the acupuncture needle intended for insertion in S4 was actually distal to the sacral body. In subjects 2 and 3, the acupuncture needles were inserted accurately in the S3 and S4 foramina. In the three subjects who had acupuncture needles inserted in the S4 foramen, the tip of the acupuncture needle was an average distance of 6.0 mm from the rectum. The acupuncture needles inserted in subjects 4 and 5 of group B were inserted accurately into the S2 and S3 foramina. Conclusions Inserting acupuncture needles into the sacral foramina of S2 and S3 at an angle of about 60° has the potential to be used for sacral nerve modulation by repeated electroacupuncture stimulation. Needling may be less accurate in subjects with higher body mass index. Because of the potential risk of perforating the rectum with the needle, this technique must be used by specialists only. Trial Registration Number 2013-026