Nerve Root Preservation Research Articles

A case report on a rare primary bone tumour: sacral chordoma presenting as sacral swelling with sphincter dysfunction

Chordoma is a rare, locally aggressive malignant tumour arising from remnants of the notochord, primarily affecting the axial skeleton, seen twice often in males above 40 years. This case report presents a 50-year-old male with primary sacral chordoma, emphasizing the need for early evaluation, treatment modalities and focusing on the importance of sacral nerve preservation during surgery for better functional outcome. Purpose of the study was to demonstrate the significance of early evaluation and diagnosis, emphasizing the importance of at least unilateral sacral nerve root preservation for optimizing postoperative bowel and bladder function. A 50-year-old male presented with sacral swelling, saddle anaesthesia, lower backache, urinary incontinence, and constipation. Examination revealed a firm, immobile sacral mass with reduced anal sphincter tone. Magnetic resonance imaging (MRI) suggested the presence of a sacral chordoma, leading to the planning of surgical resection. Intraoperatively, frozen section analysis confirmed the diagnosis of chordoma. Intraoperatively, the lesion was found to extend predominantly toward the left side, necessitating careful dissection and preservation of the sacral nerve roots on the right side. Post-operatively, the patient experienced improved bowel and bladder function, along with significant pain relief. The patient showed substantial postoperative improvement, with resolution of urinary and bowel dysfunction. Follow-up imaging revealed no tumour recurrence. Preservation of sacral nerve roots was crucial to the patient’s recovery, improving overall quality of life. This case highlights the need to consider chordoma in the differential diagnosis of sacral masses and emphasizes the importance of sacral nerve root preservation during resection to optimize functional outcomes in patients with this rare tumour.

Posterior Release, Reduction, and Intra-Articular Fusion for Irreducible Type III Atlantoaxial Rotary Fixation.

For irreducible atlantoaxial rotary fixation (AARF), anterior or posterior release was often needed before posterior reduction and fusion. Anterior atlantoaxial joint release has potential complications such as retropharyngeal abscess, persistent hoarseness, and infection. This study aims to assess the efficacy of posterior release, reduction, and intra-articular fusion without resecting the C2 nerve root on irreducible type III AARF. The data of 9 pediatric patients diagnosed with AARF who underwent posterior atlantoaxial release, reduction, and intra-articular fusion without resecting the C2 nerve root were retrospectively reviewed. Japanese Orthopaedic Association scores and Visual Analog Scale for Neck Pain were used to assess outcomes. The preoperative and follow-up assessments of atlantodens interval (ADI) were documented to evaluate the reduction of atlantoaxial joint. The patient demographics, surgery time, blood loss, bone fusion time, follow-up period, and surgery-related complications were meticulously documented. The mean follow-up duration was 35.1 ± 11.5 months. Complete reduction was achieved in 8 patients, while one patient did not achieve complete reduction. The ADI decreased significantly from 8.7 ± 2.2 mm before surgery to 2.1 ± 1.3 mm at the final follow-up. All patients demonstrated successful bone fusion, with an average fusion period of 3.7 ± 1.3 months. The Visual Analog Scale for Neck Pain at the final follow-up exhibited a significant decrease compared with preoperative values (P < .05), while no significant difference was observed in Japanese Orthopaedic Association scores. There were no complications related to surgery. Posterior atlantoaxial release, reduction, and intra-articular fusion with a C2 nerve root preservation technique is effective in the treatment of irreducible type III AARF.

Technical nuances for the resection of cervical dumbbell schwannomas.

The majority of spinal nerve sheath tumors are within the intradural/extramedullary compartment. A subset of these tumors develop extraforaminal components that gradually expand into potential spaces. Herein, the authors provide a 2D video demonstrating the technical nuances concerning resection of cervical dumbbell schwannomas with extraspinal extension. Although nerve sheath tumors with large extraforaminal extension are often associated with complications and pose unique challenges to surgeons, circumferential exposure with intradural exploration allows for gross-total resection and nerve root preservation, without need for adjuvant treatments. The use of intraoperative ultrasound, neurophysiological monitoring, Doppler imaging, and meticulous surgical techniques aided to circumvent complications.

Posterior Reduction and Intra-Articular Cage Fusion With a C2 Nerve Root Preservation Technique for Treating Posterior Atlantoaxial Dislocation Secondary to Os Odontoideum.

Posterior C1-C2 interlaminae compression fusion with iliac bone graft may lead to donor site complications and recurrent C1 posterior dislocation for posterior atlantoaxial dislocation (AAD) secondary to os odontoideum. C1-C2 intra-articular fusion often needs C2 nerve ganglion transection to facilitate exposing and manipulating the facet joint, leading to bleeding from the venous plexus and suboccipital numbness or pain. Therefore, this study was conducted to evaluate the outcomes of posterior C1-C2 intra-articular fusion with a C2 nerve root preservation technique in the treatment of posterior AAD secondary to os odontoideum. Data of the 11 patients who underwent C1-C2 posterior intra-articular fusion because of posterior AAD secondary to os odontoideum were retrospectively reviewed. Posterior reduction was performed using C1 transarch lateral mass screws and C2 pedicle screws. Intra-articular fusion was performed using a polyetheretherketone cage filled with autologous bone from the caudal edge of the C1 posterior arch and cranial edge of the C2 laminar. Outcomes were evaluated by using the Japanese Orthopaedics Association score, Neck Disability Index, and visual analog scale for neck pain. Bone fusion was evaluated by using computed tomography and 3-dimensional reconstruction. The average follow-up duration was 43.9 ± 9.5 months. All patients achieved good reduction and bone fusion, without transection of the C2 nerve roots. The mean bone fusion time was 4.3 ± 1.1 months. There was no complication related to the surgical approach and instrumentation. Function of the spinal cord manifested by the Japanese Orthopaedics Association score significantly improved ( P < .05). The Neck Disability Index score and visual analog scale for neck pain markedly decreased (all P < .05). Posterior reduction and intra-articular cage fusion with a C2 nerve root preservation technique was a promising treatment of posterior AAD secondary to os odontoideum.

Sagittal Reconstruction of the Atlantoaxial Lateral Mass Complex with an Intra-Articular Cage Fusion Technique for Degenerative Atlantoaxial Instability

To evaluate outcomes of sagittal reconstruction of the atlantoaxial lateral mass complex using a modified intra-articular cage fusion technique for treating degenerative atlantoaxial instability. Data from 15 patients with degenerative atlantoaxial instability were retrospectively reviewed. All patients underwent posterior reduction and intra-articular fusion with a cage filled with local autologous bone. Atlantodental interval values on plain radiography in flexion before and after surgery were recorded. Bone fusion was evaluated on computed tomography reconstruction, and bone fusion time was recorded. Lateral atlantoaxial joint space height before and after surgery was measured on coronal computed tomography reconstruction. Japanese Orthopaedic Association score and visual analog scale score for neck pain before surgery and at final follow-up were compared. Mean follow-up time was 40.7 ± 13.4 months. All patients achieved good reduction and solid bone fusion at follow-up. Mean fusion time was 4.4 ± 1.1 months. Atlantodental interval decreased from 8.6 ± 1.5 mm preoperatively to 1.9 ± 0.5 mm at final follow-up (P < 0.05). Lateral atlantoaxial joint space height significantly improved from 1.7 ± 0.5 mm preoperatively to 4.7 ± 0.3 mm at final follow-up (P < 0.05). Japanese Orthopaedic Association score significantly improved from 14.9 ± 1.5 preoperatively to 16.7 ± 0.6 at final follow-up (P < 0.05). Visual analog scale score for neck pain markedly decreased from 4.5 ± 1.8 preoperatively to 0.5 ± 0.6 at final follow-up (P < 0.05). Posterior reduction and intra-articular cage fusion with a C2 nerve root preservation technique is effective in treatment of degenerative atlantoaxial instability. Satisfactory reconstruction of the sagittal alignment and the height of atlantoaxial complex can be achieved.

105. Clinical outcomes of C2 nerve root sacrifice and the feasibility of its preservation in patients with congenital atlantoaxial instability

<h3>BACKGROUND CONTEXT</h3> Posterior C1-C2 fusion is a widely used fixation technique for atlantoaxial dislocation (AAD). The C2 ganglion is a restricting factor to easy access of C1-C2 joints, and placement of C1 lateral mass screws. Both intentional C2 nerve root sectioning as well as its preservation have been described and are still debatable. The associated complications and outcomes have been less studied, particularly in congenital AAD. <h3>PURPOSE</h3> To study clinical outcome after C2 nerve root sectioning as well as the feasibility of its preservation in AAD patients. <h3>STUDY DESIGN/SETTING</h3> Retrospective study/ tertiary care center. <h3>PATIENT SAMPLE</h3> This study included 190 patients who underwent posterior C1-C2 fusion for congenital AAD. <h3>OUTCOME MEASURES</h3> C2 nerve-related dysfunction; feasibilty of nerve root preservation. <h3>METHODS</h3> This is a retrospective study of 190 patients who underwent posterior C1-C2 fusion for congenital AAD using C1 lateral mass screws. The decision to cut or preserve C2 nerve root was dependent on preoperative radiology and intraoperative suitability of its preservation. Patients were followed-up at periodic intervals and questioned about C2 nerve-related dysfunction. <h3>RESULTS</h3> Complex C1-C2 morphology with highly deformed joints was seen in 139 patients. In 178 patients, the C2 nerve root was sectioned. Postoperative numbness, paresthesia and dysesthesia were present in 30.3%, 21.9% and 19.1% patients respectively. However, the symptoms were bothersome in none. They neither required medications nor disturbed the daily activities of patients. Noticeably, 9 patients (5.1%) developed non-healing occipital ulcers; most needed surgical intervention in the form of a flap cover/skin graft. C2 nerve root preservation is feasible with robust inferior C1 lateral mass and normal sized ganglion. In patients with C1-occipital condyle hypoplasia, highly oblique joints, incurved occiput, pseudofacets and anomalous vertebral artery, its preservation is technically difficult. <h3>CONCLUSIONS</h3> Though C2 nerve root sectioning did not disable the quality of life in many, a subset of patients was prone for neuropathic ulcers. Hence, its preservation should be attempted whenever feasible. It may be possible to preserve it in less complex anomalies/favorable anatomy. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Nerve Root Sparing En Bloc Resection of Sacral Chondrosarcoma: Technical Note and Review of the Literature.

Total en bloc sacrectomy provides the best long-term local control for large primary bony sacral tumors, but often requires lumbosacral nerve root sacrifice leading to loss of ambulation and/or bowel, bladder, and/or sexual dysfunction. Nerve-sparing techniques may be an option for some patients that avoid these outcomes and accordingly improve postoperative quality of life. To describe the technique for a posterior-only en bloc hemisacrectomy with maximal nerve root preservation and to summarize the available literature. A 38-yr-old woman with a 7.7×5.4×4.5 cm biopsy-proven grade 2 chondrosarcoma involving the left L5-S2 posterior elements underwent a posterior-only left hemisacrectomy tri-rod L3-pelvis fusion. A systematic review of the English literature was also conducted to identify other descriptions of high sacrectomy with distal sacral nerve root preservation. Computer-aided navigation facilitated an extracapsular resection that allowed preservation of the left-sided L5 and S3-Co roots. Negative margins were achieved and postoperatively the patient retained ambulation and good bowel/bladder function. Imaging at 9-mo follow-up showed no evidence of recurrence. The systematic review identified 4 prior publications describing 6 total patients who underwent nerve-sparing sacral resection. Enneking-appropriate resection was only obtained in 1 case though. Here we describe a technique for distal sacral nerve root preservation during en bloc hemisacrectomy for a primary sacral tumor. Few prior descriptions exist, and the present technique may help to reduce the neurological morbidity of sacral tumor surgery.

C2 Nerve Root Preservation During Posterior Fixation for Instability Secondary to Congenital Craniovertebral Junction Anomalies: Feasibility Factors and Related Outcomes

Patients with instability because of congenital craniovertebral anomalies often have complex C1-C2 osseovascular anomalies. C2 nerve root sacrifice has been described to address such difficult anatomy during posterior C1-C2 fixation and has its own downsides. Its preservation as a recent alternative poses greater surgical challenge, and the considerations differ from other causes of craniovertebral junctional instability; the pertaining outcomes have been scarcely studied. The objective of this study was to prospectively determine the feasibility and outcomes related to C2 nerve root preservation in patients with congenital atlantoaxial dislocation (CAAD) after posterior C1-C2 fixation. In this observational study, 63 patients (126 nerve roots) with CAAD after posterior fixation were prospectively assessed. Underlying osseovascular anomalies affecting the feasibility of C2 nerve root preservation, and C2 nerve-related dysfunction at 12 months follow-up were analyzed. The overall C2 nerve root preservation rate was 89.7%. Even in the presence of extreme joint obliquity/spondyloptosis and anomalous vertebral artery, it was feasible in about three fourths. After preservation, 28.3% patients developed new-onset C2 nerve root dysfunction: neuralgia in 2, dysesthesia in 6, and hypoesthesia/paresthesia in 9. The symptoms were not disabling in most patients. In most patients with CAAD, C2 nerve root preservation is feasible despite an aberrant bony and vascular anatomy. A few patients after nerve root preservation develop related symptoms that are conservatively manageable, with no significant adverse consequences. Given the controversy in the literature on C2 nerve sacrifice-related outcomes, we favor an attempt at C2 nerve root preservation.

Pros and Cons of C2 Nerve Sectioning/Preservation in Posterior Fusion for Congenital Atlantoaxial Dislocation

Deliberate C2 nerve root sectioning and its preservation have been described during posterior fusion for atlantoaxial dislocation (AAD). However, the associated outcomes have been less studied, especially in congenital AAD. Our objective was to study the clinical outcomes after C2 nerve root sectioning and the feasibility of C2 preservation in these patients. The data from 190 patients were retrospectively studied. The decision to cut or preserve the C2 nerve root was determined by the preoperative radiologic findings and intraoperative suitability of its preservation. During follow-up, the patients were questioned about C2 nerve-related dysfunction. The pros and cons of sectioning or preservation of the C2 nerve root and the related feasibility factors are also described. Complex C1-C2 anatomy that required extensive dissection and drilling was seen in 139 patients. After C2 nerve root sectioning in 178 patients, none reported bothersome hypoesthesia, paresthesia, or dysesthesia that required medication. However, 9 patients (5.1%) developed nonhealing occipital ulcers and most required flap coverage or a skin graft. C2 nerve root preservation is feasible with an adequate inferior C1 lateral mass and normal-size ganglion. In patients with C1-occipital condyle hypoplasia, extremely oblique joints, spondyloptosis, incurved occiput, pseudofacets, and anomalous vertebral artery, preservation of the C2 nerve root is difficult. The advantages of sectioning the C2 nerve root are many. However, a subset of patients is prone to morbid occipital neuropathic ulcers. After C2 nerve sectioning, one should be cautious of such complications. C2 nerve root preservation should be strongly considered for patients with favorable anatomy.

Surgical treatment of intraforaminal/extraforaminal lumbar disc herniations: Many approaches for few surgical routes.

Several disc disease nomenclatures and approaches for LDH exist. The traditional midline bone-destructive procedures together with approaches requiring extreme muscular retraction are being replaced by muscle sparing, targeted, stability-preserving surgical routes. The increasing speculation on LDHs and the innovative corridors described to treat them have lead to an extensive production of papers frequently treating the same topic but adopting different terminologies and reporting contradictory results. The review of such literature somehow confounding gave us the chance to regroup by surgical corridors the vast amount of approaches for LDH differently renamed over time. Likewise, LDHs were simplified in intra-foraminal (ILDH), extra-foraminal (ELDH), and intra-/extra-foraminal (IELDH) in relation to precise anatomical boundaries and extent of bulging disc. Through the analysis of the papers, it was possible to identify ideal surgical corridors for ILDHs, ELDHs, and IELDHs, distinguishing for each approach the exposure provided and the technical advantages/disadvantages in terms of muscle trauma, biomechanical stability, and nerve root preservation. A significant disproportion was noted between studies discussing traditional midline approaches or variants of the posterolateral route and those investigating pros and cons of simple or combined alternative corridors. Although rarely discussed, these latter represent valuable strategies particularly for the challenging IELDHs, thanks to the optimal compromise between herniation exposure and bone-muscle preservation. The integration of adequate mastery of traditional approaches together with a greater confidence through unfamiliar surgical corridors can improve the development of combined mini-invasive procedures, which seem promising for future targeted LDH excisions.

C2 and Greater Occipital Nerve: The Anatomic and Functional Implications in Spinal Surgery.

IntroductionPosterior C1-C2 fusion is a highly successful treatment for atlantoaxial instability and other pathologies of the cervical spine, with fusion rates approaching 95%-100%. However, poor visualization of the lateral masses of C1 secondary to the course of the C2 nerve root along with blood loss from the venous plexus and compression of the C2 nerve from lateral mass screws are technical obstacles that can arise during surgery. Thus, sacrifice of the C2 nerve root has long since been debated in fusions involving the C1 and C2 vertebral bodies. MethodsCadaveric dissections on four adult specimens were performed. Both intradural and extradural courses of C2 were studied in detail. The tentative site of C2 nerve root compression during placement of C1 lateral mass screws was studied in detail. Both the indication as well as the ease of C2 neurectomy were studied in relation to postoperative compression and entrapment.ResultsFour-six dorsal rootlets of C2 nerve were observed while studying the intradural course. The extradural course was studied with respect to the lateral mass of C1. The greater occipital nerve (GON) course was fairly consistent in all specimens. Transection of C2 around its ganglion would allow for proper C1 lateral mass screw placement as the course of C2 nerve interferes with proper placement of instrumentation.ConclusionC2 nerve root transection is associated with occipital numbness but this often has no effect on health-related quality of life (HRQOL). The C2 nerve root preservation is often associated with entrapment neuropathy or occipital neuralgia, which greatly affects HRQOL. The C2 nerve root transection helps in better visualization, aids in optimal placement of C1 lateral mass screws, minimizes estimated blood loss and improves surgical outcome with successful fusion.

Impact of Starting Point and C2 Nerve Status on the Safety and Accuracy of C1 Lateral Mass Screws

Literature review and meta-analysis. To compare clinical and radiographic outcomes of patients treated with C1 lateral mass screws (C1LMS), analyzing the impact of screw starting point and C2 nerve sectioning on malposition, vertebral artery injury (VAI), and C2 neuralgia and numbness. Various starting points have been suggested for C1LMS insertion. Some advocate sectioning the C2 nerve root to ease placement. Online databases were searched for English language articles between 1994 and 2012 reporting on C1LMS. Forty-two studies describing 1471 patients instrumented with 2905 C1LMS met inclusion criteria. Three surgical techniques included posterior arch starting point and center of lateral mass with nerve root preservation or sacrifice. All studies provided class III evidence. Three injuries to the vertebral artery occurred secondary to C1LMS insertion (0.1%) and 5 instances of clinically significant screw malpositions (0.2%). Postoperative imaging revealed 45 malpositioned screws (1.6%) without clinical consequences. Meta-analysis techniques demonstrated that sacrifice of the C2 nerve root caused greater postoperative numbness but less neuralgia and fewer screw malpositions. Similar rates of screw malposition and VAI arose with posterior arch screws and those starting below the arch with C2 nerve preservation, but the latter had greater numbness and pain. A thorough understanding of atlantoaxial anatomy and modern surgical techniques renders the insertion of C1LMS safe and accurate. The incidence of clinically significant malpositioned screws or VAI is <0.5%. Sacrifice of the C2 nerve root did result in fewer malpositioned screws. Numbness occurred in 11% of patients, an outcome that may be unacceptable to certain patient populations, but neuropathic pain was nearly absent with nerve sectioning. C2 nerve preservation and retraction for C1 screw placement may have higher incidence of neuropathic pain. Posterior arch screws are a viable option for patients with arches that are of adequate height.

C2 Nerve Root Transection During C1 Lateral Mass Screw Fixation

Sectioning of the C2 nerve root allows for direct visualization of the C1-2 joint and may facilitate arthrodesis. To determine the clinical and functional consequences of C2 nerve root sectioning during placement of C1 lateral mass screws. All patients undergoing C1 lateral mass screw fixation were included in this prospective study. A standard questionnaire was used to determine the severity of occipital numbness/pain and its effect on quality of life (QOL). Domains of the neck disability index were used to assess the disability related to C2 symptoms. A total of 28 patients were included (C2 transection, 8; C2 preservation, 20). A trend of decreased blood loss and length of surgery was observed in the C2 transection cohort. Occipital numbness was reported by 4 (50.0%) patients after C2 transection. Occipital neuralgia was reported by 7 (35.0%) patients with C2 preservation. None of the patients with numbness after C2 transection reported being "bothered" by it. All patients with occipital neuralgia after C2 sparing reported being "bothered" by it, and 57.1% reported a moderate to severe effect on QOL. The use of medication was reported by 5 (71.4%) patients with neuralgia vs none with numbness. Mean disability was significantly higher with neuralgia vs numbness (P = .016). C2 nerve root transection is associated with increased occipital numbness but this has no effect on patient-reported outcomes and QOL. C2 nerve root preservation can be associated with occipital neuralgia, which has a negative impact on patient disability and QOL. C2 nerve root transection has no negative consequences during C1-2 stabilization.

Surgical strategy for the management of sacral giant cell tumors: a 32-case series

Surgical treatment of sacral giant cell tumors (GCTs) is associated with a high rate of complications, and there is controversy over which type of surgical treatment is optimal. To develop an optimal treatment strategy for sacral GCTs. Retrospective/academic medical center. A total of 32 patients (18 women and 14 men) with sacral GCT who underwent surgery between August 1996 and August 2008. Local recurrence rate, surgical margins, blood loss, sacral nerve root preservation, and complications. The medical charts of 32 patients were reviewed. Patients underwent either wide resection (n=2), marginal resection (n=11), marginal resection plus curettage (n=12), or curettage alone (n=7). The curettage group and the wide resection group had the highest and lowest amounts of blood loss (4,500 vs. 1,300 mL, respectively). During follow-up (median, 42 months), 12 patients (37.5%) had local recurrence, including five of seven in the curettage group. The recurrence rate was significantly lower in the marginal excision group compared with that in the curettage group (18.2% vs. 71.4%, respectively; p=.049). Five patients had bladder dysfunction, and two patients had bowel dysfunction. Four patients who underwent marginal resection had lower limb dysfunction. Overall survival was 93.6%, and 2-year recurrence-free survival was 84.4%. Choosing an optimal surgical margin in the treatment of sacral GCTs is of great importance for local recurrence control and sacral nerve root preservation. Curettage alone should not be used to treat sacral GCT.

Nerves Are Not Made to Be Cut

Patients with instability because of congenital craniovertebral anomalies often have complex C1-C2 osseovascular anomalies. C2 nerve root sacrifice has been described to address such difficult anatomy during posterior C1-C2 fixation and has its own downsides. Its preservation as a recent alternative poses greater surgical challenge, and the considerations differ from other causes of craniovertebral junctional instability; the pertaining outcomes have been scarcely studied. The objective of this study was to prospectively determine the feasibility and outcomes related to C2 nerve root preservation in patients with congenital atlantoaxial dislocation (CAAD) after posterior C1-C2 fixation.In this observational study, 63 patients (126 nerve roots) with CAAD after posterior fixation were prospectively assessed. Underlying osseovascular anomalies affecting the feasibility of C2 nerve root preservation, and C2 nerve–related dysfunction at 12 months follow-up were analyzed.The overall C2 nerve root preservation rate was 89.7%. Even in the presence of extreme joint obliquity/spondyloptosis and anomalous vertebral artery, it was feasible in about three fourths. After preservation, 28.3% patients developed new-onset C2 nerve root dysfunction: neuralgia in 2, dysesthesia in 6, and hypoesthesia/paresthesia in 9. The symptoms were not disabling in most patients.In most patients with CAAD, C2 nerve root preservation is feasible despite an aberrant bony and vascular anatomy. A few patients after nerve root preservation develop related symptoms that are conservatively manageable, with no significant adverse consequences. Given the controversy in the literature on C2 nerve sacrifice–related outcomes, we favor an attempt at C2 nerve root preservation.

Cervical Ganglion 2 (CG2) Neurectomy: A Window to the Atlantoaxial Joint

Patients with instability because of congenital craniovertebral anomalies often have complex C1-C2 osseovascular anomalies. C2 nerve root sacrifice has been described to address such difficult anatomy during posterior C1-C2 fixation and has its own downsides. Its preservation as a recent alternative poses greater surgical challenge, and the considerations differ from other causes of craniovertebral junctional instability; the pertaining outcomes have been scarcely studied. The objective of this study was to prospectively determine the feasibility and outcomes related to C2 nerve root preservation in patients with congenital atlantoaxial dislocation (CAAD) after posterior C1-C2 fixation.In this observational study, 63 patients (126 nerve roots) with CAAD after posterior fixation were prospectively assessed. Underlying osseovascular anomalies affecting the feasibility of C2 nerve root preservation, and C2 nerve–related dysfunction at 12 months follow-up were analyzed.The overall C2 nerve root preservation rate was 89.7%. Even in the presence of extreme joint obliquity/spondyloptosis and anomalous vertebral artery, it was feasible in about three fourths. After preservation, 28.3% patients developed new-onset C2 nerve root dysfunction: neuralgia in 2, dysesthesia in 6, and hypoesthesia/paresthesia in 9. The symptoms were not disabling in most patients.In most patients with CAAD, C2 nerve root preservation is feasible despite an aberrant bony and vascular anatomy. A few patients after nerve root preservation develop related symptoms that are conservatively manageable, with no significant adverse consequences. Given the controversy in the literature on C2 nerve sacrifice–related outcomes, we favor an attempt at C2 nerve root preservation.

C2 Neurectomy

Patients with instability because of congenital craniovertebral anomalies often have complex C1-C2 osseovascular anomalies. C2 nerve root sacrifice has been described to address such difficult anatomy during posterior C1-C2 fixation and has its own downsides. Its preservation as a recent alternative poses greater surgical challenge, and the considerations differ from other causes of craniovertebral junctional instability; the pertaining outcomes have been scarcely studied. The objective of this study was to prospectively determine the feasibility and outcomes related to C2 nerve root preservation in patients with congenital atlantoaxial dislocation (CAAD) after posterior C1-C2 fixation.In this observational study, 63 patients (126 nerve roots) with CAAD after posterior fixation were prospectively assessed. Underlying osseovascular anomalies affecting the feasibility of C2 nerve root preservation, and C2 nerve–related dysfunction at 12 months follow-up were analyzed.The overall C2 nerve root preservation rate was 89.7%. Even in the presence of extreme joint obliquity/spondyloptosis and anomalous vertebral artery, it was feasible in about three fourths. After preservation, 28.3% patients developed new-onset C2 nerve root dysfunction: neuralgia in 2, dysesthesia in 6, and hypoesthesia/paresthesia in 9. The symptoms were not disabling in most patients.In most patients with CAAD, C2 nerve root preservation is feasible despite an aberrant bony and vascular anatomy. A few patients after nerve root preservation develop related symptoms that are conservatively manageable, with no significant adverse consequences. Given the controversy in the literature on C2 nerve sacrifice–related outcomes, we favor an attempt at C2 nerve root preservation.

Critical surgical techniques for giant cell tumor of sacrum

Objective To discuss the relations between optimal surgical margin and local recurrence and the impact of preserving segment of sacral nerve root on neural functions based on the clinical and pathological features of giant cell tumor(GCT).Methods From August 1996 to August 2008,48 patients with sacral GCT undergoing tumor resection were respectively analyzed,including 20 males and 28 females with an average of 34.7 years(range,19-74).The tumors were located in S1-S5 in 4 patients,S1-S4 in 7,S1-S3 in 15,S1,2 in 12,S2-S5 in 8,and S3-S5 in 2.Surgical methods included single posterior approach in 29 cases,combined anterior-posterior approach in 19.The surgical margins adopted were en-bloc in 2 patients,marginal in 15,marginal and curettage in 25,and curettage in 9.Results Forty-one of 48 cases were successfully followed up,the average time was 43.5 months(range,18-115).The average blood loss during surgery was 3560 ml(range,550-12 000).Benign lung metastasis occurred in one case 6 years after operation,2 patients died of malignant transformation.Local recurrence occurred in 15 cases.The recurrence rates in patients with en-bloc resection,marginal resection,marginal resection combined with curettage,and curettage were 0,18.2%,40.9%,66.7%,respectively.The recurrence rate of marginal group was significantly lower than that of the curettage group.Of 27 cases with bilateral S3 nerve root preservation,2 sufiered from urine or fetal dysfunction.with an incidence rate of 7.4%.While 4 of 12 patients with unilateral S3 nerve root preservation suffered from sphincter disturbance,with an incidence rate of 33.3%.The significant difference between groups in nerve root preservation was confirmed.Conclusion Optimal surgical margin for sacral GCT is of great importance to local control of tumor recurrence,the surgical procedure of sacral GCT should aim at the marginal resection on the basis of rational sacral nerve roots preservation;preservation of bilateral S3 nerve roots contributes to the recovery of sphincteral function in most patients. Key words: Giant cell tumor of bone; Sacrum; Surgical procedures,operative

Transpedicular corpectomy with posterior expandable cage placement for L1 burst fracture

The surgical management of lumbar burst usually involves either a posterior or an anterior approach. Posterior-only procedures usually rely on ligamentotaxis or manual tamping of bone fragments for decompression of the spinal canal. Transpedicular corpectomies allow for circumferential surgery through a single posterior approach; however, they are rarely done for lumbar burst fractures. The presence of intervening nerve roots is one impediment to the placement of expandable cages to reconstruct the anterior column through the transpedicular approach. Using an adaptation of a technique previously described for the treatment of spinal tumors, we were able to successfully treat a traumatic lumbar burst fracture with an expandable cage from a purely posterior approach. This treatment included decompression of the neural elements, correction of the kyphosis, restoration of vertebral body height and reconstruction of the anterior column using an expandable cage with nerve root preservation. We describe our surgical procedure in this technical note.

Continuous EMG Recordings and Intraoperative Electrical Stimulation for Identification and Protection of Cervical Nerve Roots During Foraminal Tumor Surgery

Spinal cord function is now routinely monitored with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) during surgery for intraspinal cervical dumbbell and foraminal tumors. However, upper extremity nerve roots are also at risk during these procedures. Anatomic relations are frequently difficult to interpret because the nerve roots may be displaced by the tumor. We used electrical stimulation with compound muscle action potential (CMAP) recordings at multiple sites to identify the location and course of the involved nerve root and to provide real-time information regarding the functional status of the roots to predict postoperative outcome. Ten patients were monitored during surgery for cervical dumbbell or foraminal tumors. SEPs and MEPs were monitored as a routine procedure. CMAPs were recorded from needle electrodes placed in the deltoid, biceps, triceps, and flexor carpi ulnaris muscles. Spontaneous electromyography (EMG) muscle activity was also continuously monitored. A handheld monopolar stimulation electrode was used to elicit evoked EMG responses to identify and trace the course of nerves in relation to the tumor. In four patients, the stimulation threshold was tested before and after tumor resection to predict postoperative nerve root function. Electrical stimulation with CMAP recording was successful in localizing nerve roots during tumor resection in all 10 patients. Monitoring predicted postoperative nerve root preservation after tumor removal in each case. It was possible to identify either by using low-level stimulation (<2.0 V) or by observing changes in spontaneous EMG amplitude if activation was present during surgical dissection. The monitoring of spontaneous muscle activity in response to direct or indirect surgical manipulation during tumor resection also provided continuous assessment of nerve root function and identified any physiologic disturbance induced by surgical manipulation. Electrical stimulation in the operating field and recording of CMAPs facilitated nerve root identification and predicted postoperative function during dissection and separation from ligamentous or neoplastic tissue in 10 patients. Electrical stimulation might also be useful to predict postoperative preservation of function when nerve root sacrifice is necessary and no motor response is detected intraoperatively.