Validation of a surgical drill with a haptic interface in spine surgery.

Real haptics is a technology that reproduces the sense of force and touch by transmitting contact information with real objects by converting human movements and the feel of the objects into data. In recent years, real haptics technology has been installed in several surgical devices. A custom-made surgical drill was used to drill into the posterior lamina to verify the time required for penetration detection and the distance the drill advanced after penetration. A surgeon operated with the drill and the same aspects were measured and verified. All experiments were performed on female miniature pigs at 9 months of age with a mean body weight of 23.6 kg (range 9-10 months and 22.5-25.8 kg, n = 12). There were statistically significant differences in the average reaction time and the distance travelled after penetration between a handheld drill and the drill with the penetration detection function (p < 0.001). The reaction time to detect penetration and the distance after penetration were both significantly improved when compared with those of the handheld surgical drill without the penetration detection function, with mean differences of 0.049 ± 0.019 s [95% CI 0.012, 0.086 s] and 2.511 ± 0.537 mm [95% CI 1.505, 3.516 mm]. In this study, we successfully conducted a performance evaluation test of a custom-made haptic interface surgical drill. A prototype high-speed drill with a haptic interface accurately detected the penetration of the porcine posterior lamina.

Hidden blood loss in extreme lateral interbody fusion for adult spinal deformity.

BACKGROUND: Extreme lateral interbody fusion (XLIF) is often used with posterior spinal fixation (PSF) to treat adult spinal deformity (ASD). However, the amount of intraoperative blood loss (IBL) reported for XLIF may underestimate the total blood loss (TBL). The objective of this study was to determine the total perioperative blood loss in XLIF for ASD. METHODS: We assessed 30 consecutive ASD patients with Schwab-SRS type L (mean age: 68.7 ± 8.2 years; mean follow-up 2.0 ± 1.3 years) who were treated by multilevel XLIF (mean, 2.5 ± 0.6 levels) followed by PSF after 3-5 days. We calculated the TBL after XLIF by the Gross equation, by hemoglobin (Hb) balance, and by the Orthopedic Surgery Transfusion Hemoglobin European Overview (OSTHEO) formula. We defined hidden blood loss (HBL) as the difference between the TBL and IBL. Pearson correlation, Spearman correlation, and multiple logistic regression analysis were performed to investigate the risk factors related to HBL. RESULTS: Post-XLIF blood tests showed a significant decrease in the Hb (from 11.8 ± 1.1 mg/dl to 10.6 ± 1.1 mg/dl) and hematocrit (from 36.0 ± 3.2% to 32.5 ± 3.2%). Although the mean IBL was relatively small (33 ± 52 mL), we calculated the TBL as 291 ± 171 mL (Gross equation) and the HBL as 258 ± 168 mL by Gross equation, which was 8 times greater than the IBL on average. There was no difference in the results obtained using the three methods. Multiple logistic regression analysis indicated preoperative lumber lordosis was the risk factor of high HBL (Odds ratio = 1.085, 95%CI: 1.006-1.170, p = 0.035). CONCLUSIONS: The HBL in XLIF was 8 times greater than the IBL. During the perioperative course of correction and fusion surgery for ASD with XLIF, surgeons need to pay attention not to underestimate the TBL.

Risk predictors of perioperative complications for the palliative surgical treatment of spinal metastasis.

BACKGROUND: The complication rate for palliative surgery in spinal metastasis is relatively high, and major complications can impair the patient's activities of daily living. However, surgical indications are determined based primarily on the prognosis of the cancer, with the risk of complications not truly considered. We aimed to identify the risk predictors for perioperative complications in palliative surgery for spinal metastasis. METHODS: A multicentered, retrospective review of 195 consecutive patients with spinal metastasis who underwent palliative surgeries with posterior procedures from 2001 to 2016 was performed. We evaluated the type and incidence of perioperative complications within 14 days after surgery. Patients were categorized into either the complication group (C) or no-complication group (NC). Univariate and multivariate analyses were used to identify potential predictors for perioperative complications. RESULTS: Thirty patients (15%) experienced one or more complications within 14 days of surgery. The most frequent complications were surgical site infection (4%) and motor weakness (3%). A history of diabetes mellitus (C; 37%, NC; 9%: p < 0.01) and surgical time over 300 min (C; 27%, NC; 12%: p < 0.05) were significantly associated with complications according to univariate analysis. Increased blood loss and non-ambulatory status were determined to be potential risk factors. Of these factors, multivariate logistic regression revealed that a history of diabetes mellitus (OR: 6.6, p < 0.001) and blood loss over 1 L (OR: 2.7, p < 0.05) were the independent risk factors for perioperative complications. There was no difference in glycated hemoglobin A1c between the diabetes patients with and without perioperative complications. CONCLUSIONS: Diabetes mellitus should be used for the risk stratification of surgical candidates regardless of the treatment status, and strict prevention of bleeding is needed in palliative surgeries with posterior procedures to mitigate the risk of perioperative complications.

Efficacy of hyaluronic acid on intervertebral disc inflammation: An in vitro study using notochordal cell lines and human disc cells.

Hyaluronic acid (HA) is widely recognized as a therapeutic target and currently used in medicine. However, HA metabolism during intervertebral disc degeneration (IVDD) has not been completely elucidated. This study aimed to evaluate the efficacy of HA on intervertebral disc (IVD) inflammation and identify the main molecules modulating HA degradation in IVDs. To assess HA function in IVD cells in vitro, we treated human disc cells and U-CH1-N cells, a notochordal nucleus pulposus cell line, with HA or hyaluronidase. Real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis showed that tumor necrosis factor alpha (TNF-α)-mediated induction of the expression of TNF-α and cyclooxygenase-2 (COX2) was clearly neutralized by HA treatment, and the expression of TNF-α and COX2 was significantly induced by hyaluronidase treatment in both cell types. Additionally, Western blot analysis showed that hyaluronidase-induced phosphorylation of p38 and Erk1/2, and that TNF-α-mediated phosphorylation of p38 and Erk1/2 was clearly reduced by HA addition. In degenerating human IVD samples, immunohistochemistry for hyaluronidase showed that the expression of hyaluronidases including HYAL1, HYAL2, and cell migration-inducing protein (CEMIP) tended to increase in accordance with IVDD. In particular, HYAL1 showed statistically significant differences. In vitro study also confirmed a similar phenomenon that TNF-α treatment increased both messenger RNA and protein expression in both cell types. Our results demonstrated that HA could potentially suppress IVDD by regulating p38 and Erk1/2 pathways, and that the expression of HYAL1 was correlated with IVDD progression. These findings indicated that HYAL1 would be a potential molecular target for suppressing IVDD by controlling HA metabolism.

Spinal fractures in diffuse idiopathic skeletal hyperostosis: Advantages of percutaneous pedicle screw fixation.

PURPOSE: To validate the effectiveness of percutaneous pedicle screw (PPS) fixation for spinal fractures associated with diffuse idiopathic skeletal hyperostosis (DISH) by comparing surgical outcomes for PPS fixation and conventional open posterior fixation. Patients with DISH are vulnerable to unstable spinal fractures caused by trivial trauma, and these fractures have high rates of delayed paralysis, postoperative complications, and mortality. METHODS: This retrospective study assessed surgical outcomes for 16 patients with DISH (12 men; mean age 76.1 ± 9.4 years) who underwent PPS fixation for spinal fractures (pedicle screw (PS) group), and for a control group of 25 patients with DISH (18 men; mean age 77.9 ± 9.9 years) who underwent conventional open fixation (O group) at our affiliated hospitals from 2007 to 2017. We evaluated the preoperative physical condition (American Society of Anesthesiologists (ASA) classification), neurological status (Frankel grade), and improvement after surgery, fusion length, operating time, estimated blood loss, and perioperative complications. RESULTS: Preoperatively, the PS group consisted of one ASA-1 patient, eight ASA-2 patients, six ASA-3 patients, and one ASA-4 patient; by Frankel grade, there were 2 grade B patients, 13 grade C, 4 grade D, and 6 grade E patients. The O group had 2 ASA-1 patients, 13 ASA-2, 9 ASA-3, and 1 ASA-4 patients. Frankel grades in the O group reflected severe neurological deficits, with 3 grade C patients, 2 grade D, and 11 grade E ( p = 0.032) patients. The two groups had similar rates of neurological improvement (33.3% of PS and 40.0% of O patients; p = 0.410) and mean fusion length (PS 5.1 ± 0.8 segments; O 4.9 ± 1.2). The mean operating time and estimated blood loss were 168.1 ± 46.7 min and 133.9 ± 116.5 g, respectively, in the PS group, and 224.6 ± 49.8 min and 499.9 ± 368.5 g in the O group. Three O-group patients died of hypovolemic shock, respiratory failure, and pneumonia, respectively, within a year of surgery. CONCLUSION: Conventional open posterior fixation and PPS fixation for DISH-related spinal fractures were similar in fusion length and neurological improvement. However, PPS fixation was less invasive and had lower complication rates.

Potential involvement of semaphorin 3A in maintaining intervertebral disc tissue homeostasis.

Intervertebral discs (IVDs) are avascular; however, ingrowth of blood vessels into their outer regions has been noted during the progression of degeneration. The mechanisms underlying vascularization in IVD degeneration are not completely understood. Semaphorin 3A (Sema3A), originally characterized as a chemorepulsive factor for growing axons in the developing nervous system, inhibits angiogenesis. This study aimed to elucidate the potential involvement of Sema3A in maintaining tissue homeostasis within the avascular IVD. We demonstrated that the mRNA expression of Sema3A was higher in rat annulus fibrosus (AF) than in nucleus pulposus (NP) and that its expression level decreased with age. Both mRNA and protein expression level of Sema3A was also markedly suppressed in AF tissues of a rat IVD degeneration model. Both real-time RT-PCR and Western blot clearly indicated that Sema3A expression significantly reduced by treating inflammatory cytokines in rat AF cells. In a gain- and loss-of-function study, we observed that Sema3A reduced the catabolic shift in rat AF cells. In addition, our results indicated that Sema3A potentially inhibited the IL-6/JAK/STAT pathway. Finally, BrdU assay and tube formation assay revealed that treatment of recombinant Sema3A significantly blocks both proliferation and tube formation of HUVEC. Our results indicate that Sema3A may help maintain IVD tissue homeostasis. Thus, although further studies are needed, Sema3A may be a potential molecular target for suppressing IVD degeneration. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

A rare case of intradural and extramedullary epidermoid cyst after repetitive epidural anesthesia: case report and review of the literature.

BACKGROUND: Spinal epidermoid cysts are benign tumors, which are rarely seen as an intradural extramedullary spinal cord tumor in the conus medullaris region. Acquired spinal epidermoid cysts are mostly caused by iatrogenic procedures, such as lumbar puncture, and the majority of acquired spinal epidermoid cysts have been reported below the L1 level, because lumbar puncture is usually performed around the iliac crest. Here, we report an extremely rare case of an epidermoid cyst that occurred as an intradural and extramedullary spinal cord tumor attached to the conus medullaris after repetitive epidural anesthesia. CASE PRESENTATION: A 67-year-old female presented with a low back pain and left sciatica. Although the patient had experienced occasional mild low back pain for several years, her low back pain markedly worsened 2 months before her visit, as well as newly developed left sciatica resulting in intermittent claudication. She had a history of several abdominal surgeries. All abdominal procedures were performed under general anesthesia with epidural anesthesia in her thoracolumbar spine. Magnetic resonance imaging of her lumbar spine demonstrated an intradural extramedullary spinal cord tumor at the T12-L1 level. Because her symptoms deteriorated, the tumor excision was performed using microscopy. Histological examination of the specimens demonstrated that the cyst walls lined with stratified squamous keratinizing epithelium surrounded by the outer layer of collagenous tissue with the absence of skin adnexa. A diagnosis of epidermoid cysts was confirmed. Her MRI showed complete resection of the tumor, and there was no recurrence at 2-year follow-up. CONCLUSIONS: In this case report, epidermoid cells might be contaminated into the spinal canal during repetitive epidural anesthesia. The patient was successfully treated by complete resection, and there was no recurrence at 2-year follow-up with a good clinical outcome. However, long-term follow-up is required for a potential risk of tumor recurrence.

Osteochondritis dissecans on the medial aspect of the humeral head.

The case of a 29-year-old man who had osteochondritis dissecans on the medial aspect of the humeral head is reported. Repetitive micro-trauma at a low elevated arm position was thought to have induced the osteochondral lesion.