Classification and Reliability of Lumbar Facet Cysts Grading Scales

BACKGROUND

The presence of symptomatic lumbar facet cysts has been associated with segmental instability. Given this association, decompression versus decompression with fusion is a frequently debated topic. Multiple grading scales have been devised to identify patients at high risk for development of cyst recurrence; however, there exists no external evaluation of these scales.

METHODS

A retrospective review of 54 patients undergoing initial treatment for lumbar synovial cysts at a single institution over the past 12 years was conducted. Surgical treatment consisted of decompression with cystectomy without fusion. Patients were assessed and classified according to the NeuroSpine Surgery Research Group (NSURG) and Rosenstock Classification systems. Five neurosurgeons reviewed the preoperative magnetic resonance images, and results were classified. Interrater reliability was assessed using both Gwet's AC1 coefficient and Krippendorff's alpha. A 1-way analysis of variance was used to evaluate predictive ability of both classification systems.

RESULTS

In total, of the 54 patients who underwent decompression, 7 had cyst recurrence. Overall cyst recurrence was most common in NSURG grade 2 cysts (3/12, 25%) followed by grade 1 cysts (4/27, 14.8%). Of the NSURG grade 3 and 4 patients, none had cyst recurrence. In the Rosenstock grades the most common recurrence was in grade 3 cysts (1/4, 25%) followed by grade 1 cysts (5/26, 19.2%). Interrater reliability demonstrated good reproducibility on Gwet's AC1 and Krippendorff's alpha on both grading scales. Neither score was predictive of cyst recurrence (P > 0.05).

CONCLUSIONS

The Rosenstock and NeuroSpine scores demonstrate good overall interrater reliability but are inconsistent in their ability to predict recurrence of lumbar facet cysts.

Retroperitoneal Exposure of the Anterior Lumbar Spine

BACKGROUND

Anterior lumbar spine procedures such as anterior lumbar interbody fusion (ALIF) are used commonly to treat multiple pathologies, including pseudoarthrosis and degenerative disk disease. It is generally a safe and effective procedure, but an anterior approach to the lumbar spine requires critical navigation of the surgical window to avoid delicate structures. An operative technique should maximize the exposure without an increased risk of iatrogenic injury.

OBJECTIVE

To describe in detail a retroperitoneal exposure of the anterior lumbar spine.

METHODS

This surgical approach is a unique variation of standard anterior lumbar spine exposure techniques. This technique is described and illustrated in detail with an accompanying Supplemental Digital Content: video. Institutional Review Board (IRB) approval was not required because this is a variation of current techniques. Patient consent was obtained for the procedure and use of operative pictures and videos.

RESULTS

Precise details of the technique are described. The surgical video demonstrates the technique for the L5-S1 ALIF approach.

CONCLUSION

This technique is a novel variation of the standard retroperitoneal exposure of the anterior lumbar spine. The incision placement, size, and dynamic blunt retraction of this approach limit tissue disruption and provide an efficient exposure that has not been previously described in the literature.

Comparison of Decompression versus Decompression and Fusion for Lumbar Synovial Cysts and Predictive Factors for Cyst Recurrence

BACKGROUND

The management of lumbar synovial cysts (LSC) has been a controversial topic for many years. Whereas many authors label LSC as markers of instability and thus necessitating fusion, others suggest that decompression alone without fusion is a viable initial treatment option. Our objective was to clarify outcomes in patients undergoing decompression alone and decompression with fusion for symptomatic LSC and identify factors for cyst recurrence.

METHODS

A retrospective case series was performed of all patients undergoing initial treatment for LSC at a single institution ranging from January 1999 to February 2020. Surgical treatment included either decompression with cystectomy or decompression with cystectomy and a fusion procedure. Preoperative symptoms were collected and included radicular pain, motor deficits, sensory deficits, or bowel/bladder changes. Radiographic data were calculated individually and confirmed with radiology reports. Categorical variables were assessed using χ² analysis and continuous variables were assessed with the 2-sample t test.

RESULTS

In total, 161 patients were identified as presenting with symptomatic LSC. Of these, 104 patients underwent decompression alone versus 57 who underwent decompression and fusion. In the decompression group 11 patients required reoperation at the level of the cyst compared with none in those undergoing fusion as their initial procedure (10.5% vs. 0%, P = 0.012). On subgroup analysis of those undergoing decompression as their initial procedure, patients with cyst recurrence demonstrated a statistically significant greater coronal facet inclination angle compared with those without cyst recurrence (52.4° vs. 40.6°, P = 0.02).

CONCLUSIONS

Decompression alone is a reasonable choice for the initial management of LSC, although it does carry a significant risk of same-level reoperation due to cyst recurrence and spondylolisthesis. Preoperative coronal facet inclination angle may be a useful measurement in predicting cyst recurrence following decompression.

Synthesis and evaluation of 17α-triazolyl and 9α-cyano derivatives of estradiol

A variety of 17α-triazolyl and 9α-cyano derivatives of estradiol were prepared and evaluated for binding to human ERβ in both a TR-FRET assay, as well as ERβ and ERα agonism in cell-based functional assays. 9α-Cyanoestradiol (5) was nearly equipotent as estradiol as an agonist for both ERβ and ERα. The potency of the 17α-triazolylestradiol analogs is considerably more variable and depends on the nature of the 4-substituent of the triazole ring. While rigid protein docking simulations exhibited significant steric clashing, induced fit docking providing more protein flexibility revealed that the triazole linker of analogs 2d and 2e extends outside of the traditional ligand binding domain with the benzene ring located in the loop connecting helix 11 to helix 12.

Association of helmet use with traumatic brain and cervical spine injuries following bicycle crashes

Background: The use of bicycle helmets in preventing traumatic brain injuries (TBI) is frequently cited but data remain inconclusive. Additionally, the effects of helmets on cervical spine injuries (CSI) are debated.Methods: We performed a retrospective review of all adult patients with bicycle crashes presenting to one level 1 trauma center in Wisconsin from 2010 to 2016. Patients were divided into two groups: helmeted and un-helmeted.Results: In total 287 patients were included; 149 un-helmeted (51.9%) and 138 helmeted (48.9%). Helmeted riders had radiographic evidence of traumatic brain injury in 20.3% of cases compared to 40.3% of un-helmeted (p < 0.001). On average, helmeted riders had a similar injury severity score of 7.80 (standard deviation (SD) = 7.18) compared with 8.25 (SD = 9.98) in the un-helmeted group (p = 0.68). CSI occurred in 16 (10.7%) un-helmeted patients compared with 15 (10.9%) helmeted patients (p = 0.707). Of the un-helmeted group, four patients (2.7%) were found to have a cervical spine fracture compared with 12 (8.7%) helmeted patients (p = 0.037).Conclusion: Helmet use demonstrated a statistically significant advantage in the prevention of traumatic brain injuries. No significant difference was found regarding the incidence of severity of cervical spine injuries. These results do not demonstrate any statistically significant benefit in the prevention of cervical spine injuries with helmet use. In contrast, helmet use was found to convey a significant protective advantage in the prevention of traumatic brain injuries compared to no helmets.

Evaluation of α-hydroxycinnamic acids as pyruvate carboxylase inhibitors

Through a structure-based drug design project (SBDD), potent small molecule inhibitors of pyruvate carboxylase (PC) have been discovered. A series of α-keto acids (7) and α-hydroxycinnamic acids (8) were prepared and evaluated for inhibition of PC in two assays. The two most potent inhibitors were 3,3'-(1,4-phenylene)bis[2-hydroxy-2-propenoic acid] (8u) and 2-hydroxy-3-(quinoline-2-yl)propenoic acid (8v) with IC₅₀ values of 3.0 ± 1.0 μM and 4.3 ± 1.5 μM respectively. Compound 8v is a competitive inhibitor with respect to pyruvate (K_i = 0.74 μM) and a mixed-type inhibitor with respect to ATP, indicating that it targets the unique carboxyltransferase (CT) domain of PC. Furthermore, compound 8v does not significantly inhibit human carbonic anhydrase II, matrix metalloproteinase-2, malate dehydrogenase or lactate dehydrogenase.

Clival meningocele causing bilateral hearing loss in a child due to superficial siderosis of the central nervous system: case report

Superficial siderosis (SS) of the CNS is a rare and often unrecognized condition. Caused by hemosiderin deposition from chronic, repetitive hemorrhage in the subarachnoid space, it results in parenchymal damage in the subpial layers of the brain and spinal cord. T2-weighted MRI shows the characteristic hypointensity of hemosiderin deposition, classically occurring around the cerebellum, brainstem, and spinal cord. Patients present with progressive gait ataxia and sensorineural hearing impairment. Although there have been several studies, case reports, and review articles over the years, the clear pathophysiology of subarachnoid space hemorrhage remains to be elucidated. The proposed causes include prior intradural surgery, prior trauma, tumors, vascular abnormalities, nerve root avulsion, and dural abnormalities. Surgical repair of a dural defect associated with SS has been shown to be efficacious at preventing symptomatic progression. There have been several reports of dural defects within the spinal canal treated with surgery. Here, the authors present the first known case of a dural defect of the ventral skull base, namely a clival meningocele, presumed to be causing SS. In this case report, a 10-year-old girl with a history of head trauma at the age of 3 years was found to have a clival meningocele 3 years after her original trauma. On follow-up imaging, the patient was found to have radiographic growth of the meningocele along with evidence of SS of the CNS. The patient was treated conservatively until she began to have progressive hearing loss. It was presumed that the growing meningocele was the source of her SS. An endoscopic endonasal transclival approach with a multilayer dural reconstruction was performed to fix the dural defect and repair the meningocele in hopes of mitigating the progression of her symptoms. At her 12-month postoperative follow-up, she was doing well, with audiometry showing a slightly decreased hearing threshold in the left ear but improved speech discrimination bilaterally. Postoperative MRI showed a stable level of hemosiderin deposition and meningocele repair. Long-term follow-up will be necessary to evaluate for continued clinical stabilization or possible improvement.

Microsurgical Pontine Descending Tractotomy in Cases of Intractable Trigeminal Neuralgia

BACKGROUND

Current treatment strategies in patients with trigeminal neuralgia (TN) include trials of medical therapy and surgical intervention, when necessary. In some patients, pain is not adequately managed with these existing strategies.

OBJECTIVE

To present a novel technique, ventral pontine trigeminal tractotomy via retrosigmoid craniectomy, as an adjunct treatment in TN when there is no significant neurovascular compression.

METHODS

We present a nonrandomized retrospective comparison between 50 patients who lacked clear or impressive arterial neurovascular compression of the trigeminal nerve as judged by preoperative magnetic resonance imaging and intraoperative observations. These patients had intractable TN unresponsive to previous treatment. Trigeminal tractotomy was performed either alone or in conjunction with microvascular decompression. Stereotactic neuronavigation was used during surgery to localize the descending tract via a ventral pontine approach for descending tractotomy.

RESULTS

Follow-up was a mean of 44 months. At first follow-up, 80% of patients experienced complete relief of their pain, and 18% had partial relief. At the most recent follow-up, 74% of patients were considered a successful outcome. Only 1 (2%) patient had no relief after trigeminal tractotomy. Of those with multiple sclerosis-related TN, 87.5% experienced successful relief of pain at their latest follow-up.

CONCLUSION

While patient selection is a significant challenge, this procedure represents an option for patients with TN who have absent or equivocal neurovascular compression, multiple sclerosis-related TN, or recurrent TN.