A Sternum-Disk Distance Method to Identify the Skin Level for Approaching a Surgical Segment without Fluoroscopy Guidance during Anterior Cervical Discectomy And Fusion

STUDY DESIGN: A retrospective review of prospectively collected data. PURPOSE: To introduce the sternum-disk distance (SDD) method for approaching the exact surgical level without C-arm guidance during anterior cervical discectomy and fusion (ACDF) surgery and to evaluate its accuracy and reliability. OVERVIEW OF LITERATURE: Although spine surgeons have tried to optimize methods for identifying the skin level for accessing the operative disk level without C-arm guidance during ACDF, success has rarely been reported. METHODS: In total, 103 patients who underwent single-level ACDF surgery with the SDD method were enrolled. The primary outcome measure was the accuracy of the SDD method. The secondary outcome measures were the mean SDD value at each cervical level from the cranial margin of the sternum in the neutral and extension positions of the cervical spine and the inter- and intra-observer reliability of the SDD outcome determined using repeated measurements by three orthopedic spine surgeons. RESULTS: The SDD accuracy (primary outcome measure) was indicated in 99% of the patients (102/103). The mean SDD values in the neutral-position magnetic resonance imaging (MRI) were 108.8 mm at C3–C4, 85.3 mm at C4–C5, 64.4 mm at C5–C6, 44.3 mm at C6–C7, and 24.1 mm at C7–T1; and those in the extension-position MRI were 112.9 mm at C3–C4, 88.7 mm at C4–C5, 67.3 mm at C5–C6, 46.5 mm at C6–C7, and 24.3 mm at C7–T1. The Cohen kappa coefficient value for intra-observer reliability was 0.88 (excellent reliability), and the Fleiss kappa coefficient value for inter-observer reliability as reported by three surgeons was 0.89 (excellent reliability). CONCLUSIONS: Based on the results of the present study, we recommend performing ACDF surgery using the SDD method to determine the skin level for approaching the surgical cervical segment without fluoroscopic guidance.

Feasibility Study of Free-Hand Technique for Pedicle Screw Insertion at C7 without Fluoroscopy-Guidance

STUDY DESIGN: Retrospective interventional study. PURPOSE: To introduce a free-hand pedicle screw (PS) insertion technique without fluoroscopic guidance in the C7 vertebra and evaluate the procedure's feasibility and radiologic outcomes. OVERVIEW OF LITERATURE: Although PS insertion at C7 has been recognized as a critical procedure in posterior cervical fusion surgery, conventional techniques for C7 PS have several limitations. METHODS: Thirty two patients (64 screws) who underwent PS insertion in C7 with the novel technique were included in this study. Postoperative clinical and radiological outcomes were evaluated. Special attention was paid to the presence of any problems in the screw position including cortical breaches of the PS and encroachment of the PS into the spinal canal or the vertebral foramen. This novel technique for PS insertion in C7 without fluoroscopy guidance had three key elements. First, the ideal PS entry point was chosen near the C6-7 facet joint using preoperative images. Second, the convergent angle distance was measured at axial computed tomography (CT) imaging, which defined the distance between the tip of C7 spinous process and the extended line passing through the pedicle axis from the ideal entry point. Third, the cranial-caudal angle distance was measured in sagittal CT images, which defined the distance between the tip of the C7 spinous process and the extended line passing through the pedicle axis. RESULTS: Cortical breach on postoperative CT images was observed in three screws. All violated only the lateral wall of the affected pedicle. The breached screws occurred in the initial five cases. Postoperative neurologic deterioration was not observed in any patient, regardless of cortical breaching. CONCLUSIONS: The novel technique successfully allows for C7 PS to be placed and is associated with a low rate of cortical breach.

Prognostic Factors for Postsurgical Recovery of Deltoid Palsy due to Cervical Disc Herniations

STUDY DESIGN: Retrospective multicenter study. PURPOSE: We aimed to investigate prognostic factors affecting postsurgical recovery of deltoid palsy due to cervical disc herniation (CDH). OVERVIEW OF LITERATURE: Little information is available about prognostic factors affecting postsurgical recovery of deltoid palsy due to CDH. METHODS: Sixty-one patients with CDH causing deltoid palsy (less than grade 3) were included in this study: 35 soft discs and 26 hard discs. Average duration of preoperative deltoid palsy was 11.9 weeks. Thirty-two patients underwent single-level surgery, 22 two-level, four three-level, and three four-level. Patients with accompanying myelopathy, shoulder diseases, or peripheral neuropathy were excluded from the study. RESULTS: Deltoid palsy (2.4 grades vs. 4.5 grades, p<0.001) and radiculopathy (6.4 points vs. 2.1 points, p<0.001) significantly improved after surgery. Thirty-six of 61 patients (59%) achieved full recovery (grade 5) of deltoid palsy, with an average time of 8.4 weeks. Longer duration of preoperative deltoid palsy and more severe radiculopathy negatively affected the degree of improvement in deltoid palsy. Age, gender, number of surgery level, and disc type did not affect the degree of improvement of deltoid palsy. Contrary to our expectations, severity of preoperative deltoid palsy did not affect the degree of improvement. Due to the shorter duration of preoperative deltoid palsy, in the context of rapid referral, early surgical decompression resulted in significant recovery of more severe grades (grade 0 or 1) of deltoid palsy compared to grade 2 or 3 deltoid palsy. CONCLUSIONS: Early surgical decompression significantly improved deltoid palsy caused by CDH, irrespective of age, gender, number of surgery level, and disc type. However, longer duration of deltoid palsy and more severe intensity of preoperative radiating pain were associated with less improvement of deltoid palsy postoperatively.

Repair Using Conventional Implant for Ruptured Annulus Fibrosus after Lumbar Discectomy: Surgical Technique and Case Series

STUDY DESIGN: A retrospective review of annulus fibrosus repair (AR) using a novel technique with a conventional implant. PURPOSE: The purpose of this study was to present the feasibility and clinico-radiological outcomes of a novel AR technique using a conventional implant to minimize recurrence following a lumbar discectomy (LD). OVERVIEW OF LITERATURE: Conventional repair techniques to prevent recurrence following LD have several drawbacks. The AR surgical technique has received little attention as an adjunct to LD. METHODS: A total of 19 patients who underwent novel AR following LD, and who were available for follow-up for at least three years, were enrolled in this study. Several variables, including the type and size of disc herniation, and the degree of disc degeneration, were evaluated preoperatively. Postoperatively, the presence of clinical and radiological recurrence of disc herniation was evaluated from pain intensity and functional statuses, as well as an enhanced L-spine magnetic resonance imaging at the final follow-up. The presence of a peripheral hollow rim and inserted anchor mobilization were also evaluated during the follow-up. RESULTS: During follow-ups, there were no recurrences of disc herniation or complications, including neurovascular complications. Pain and functional disability improved significantly after surgery, and the improvement was maintained throughout the three-year follow-up period. No mobilization or implant peripheral hollow rim was observed during the follow-up. CONCLUSIONS: This study examined the feasibility of a novel and easily available annulus implant technique following LD. These results suggest performing AR with this technique may be a valuable alternative for optimizing outcomes, if the procedure is performed in proper candidates.

The Surgical Treatment of the Cervical Myelopathy with Laminectomy and Posterior Fusion by using Lateral Mass Screw Fixation / 대한정형외과학회잡지

PURPOSE: This prospective study was designed to investigate the outcomes of laminectomy and fusion with using lateral mass screw (LMS) fixation for the treatment of cervical myeolpathy. MATERIALS AND METHODS: We studied a series of 26 consecutive patients with cervical myelopathy and who were planned to undergo laminectomy and fusion with using LMS fixation. MRI was done to investigate the high signal intensity lesion (HSIL) in the cord on the T2 weighted sagittal images. The JOA score, the grip and release test, the finger escape sign, and Hoffman's sign were checked. We analyzed the clinical outcomes depending on the high signal intensity lesion in the cord, the preoperative kyphosis, and the preoperative instability. RESULTS: The indications for lateral mass screw fixation was kyphotic deformity, segmental instability or ossification of the ligament flavum (OLF). Patients with HSIL on the T2-weighted sagittal MRI was found in 17 patients. The JOA score, the grip and release test, and the finger escape sign were significantly improved after the operation and at the 2 year follow up. The patients with HSIL on the T2-weighted sagittal MRI or segmental instability had a significantly lower preoperative JOA score and a poor postoperative recovery as assessed by the JOA score. CONCLUSION: Laminectomy and fusion using lateral mass screw fixation for the surgical treatment of cervical myelopathy, which is associated with kyphotic deformity, instability or OLF, is considered a safe and effective treatment option to prevent postoperative kyphosis.