Jung-Woo Hur

Prospective Comparison Study Between the Fluoroscopy-guided and Navigation Coupled With O-arm-guided Pedicle Screw Placement in the Thoracic and Lumbosacral Spines.

Study Design: This is a prospective randomized comparison study between the fluoroscopy-guided and navigation coupled with O-arm–guided pedicle screw placement in the thoracic and lumbosacral spines. Objective: The objective of the study was to evaluate the accuracy and clinical benefits of a navigation coupled with O-arm–guided method in the thoracic and lumbar spines by comparing with a C-arm fluoroscopy-guided method. Methods: Under fluoroscopy guidance, 138 pedicle screws were inserted from T9 to S1 in 20 patients, and 124 pedicle screws were inserted from T9 to S1 in 20 patients using the navigation. The position of the screws within the pedicle was assessed from grade 0 (no violation cortex) to grade 3 (>4 mm violation), and the location of the violated cortex was determined. Preparation time of each equipment setting, time for screwing, and the number of x-ray shots were evaluated. Results: The number of screws observed as grade 0 was 121 (87.7%) in the fluoroscopy-guided group and 114 (91.9%) in the navigation-guided group. The lateral cortex was most commonly involved in the fluoroscopy-guided group (6 cases, 35.3%), and the medial cortex was most common in the navigation-guided group (4 cases, 40%). The mean time required for preparation for screw placement was 3.7 minutes in the fluoroscopy-guided group and 14.2 minutes in the navigation-guided group. Average screwing time was 3.6 minutes in the fluoroscopy-guided group and 4.3 minutes in the navigation-guided group. The mean number of x-ray shots for each screw placement in the fluoroscopy-guided group was 6.5. Postoperatively, 2 patients with misplacement of a screw under fluoroscopy guidance presented ipsilateral leg paresthesia, possibly related to the screw position. Conclusions: The present prospective study reveals that the pedicle screw placement guided by the navigation coupled with O-arm system was more accurate and safer than that under fluoroscopy guidance.

Comparative study of lumbopelvic sagittal alignment between patients with and without sacroiliac joint pain after lumbar interbody fusion.

Study Design. A retrospective case-control study. Objective. To elucidate the role of changes of lumbopelvic sagittal alignment in the pathogenesis of sacroiliac joint (SIJ) pain after posterior lumbar interbody fusion (PLIF) by comparing these values with the control, patients without SIJ pain. Summary of Background Data. There has been no study specifically addressing the relation between lumbopelvic sagittal alignment and SIJ pain after PLIF. Methods. Among 346 patients who underwent PLIF between June 2009 and April 2012, patients with postoperative SIJ pain who responded to SIJ block were enrolled. For a control group, patients who were matched for sex, age group, the number of fused level, and fusion to sacrum were randomly selected. The patients were assessed using clinical and radiological parameters including age, sex, diagnosis, bone mineral density, body mass index, lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt, and sacral slope. Target LL (PI + 9°), achieved rate of LL (postoperative LL/target LL × 100), and LL-PI mismatch (&Dgr;) were also calculated and compared between 2 groups. Results. Twenty-three patients (9 males and 14 females) with SIJ pain and 46 patients (18 males and 28 females) without SIJ pain were assessed. Postoperatively, the SIJ pain group showed significantly greater pelvic tilt (19.88 ± 10.42°, P = 0.03), smaller achieved rate of LL (64.3%, P = 0.02), and substantial residual LL-PI mismatch (−14.45 ± 12.16°, P = 0.03) than the non-SIJ pain group (14.25 ± 7.68°, 73.2%, and −8.26 ± 9.12°, respectively). The degree of correlation between LL and PI in both the SIJ pain group and the non-SIJ pain group was positive preoperatively (r = 0.569; P = 0.003, r = 0.591; P = 0.000, respectively). Although correlation of the SIJ pain group remained positive postoperatively (r = 0.601, P = 0.002), it became strongly positive in the non-SIJ pain group (r = 0.856, P = 0.000). Conclusion. This study indicates that lumbopelvic sagittal imbalance inferred from greater pelvic tilt and inadequately restored LL may play a central role in the development of SIJ pain after PLIF. Thus, it is important to restore lumbopelvic sagittal balance and to evaluate PI to determine the ideal LL that is needed to prevent postoperative SIJ pain. Level of Evidence: 3

Sagittal Sacropelvic Morphology and Balance in Patients with Sacroiliac Joint Pain Following Lumbar Fusion Surgery

Objective To investigate the sagittal sacropelvic morphology and balance of the patients with SIJ pain following lumbar fusion. Methods Among 452 patients who underwent posterior lumbar interbody fusion between June 2009 and January 2013, patients with postoperative SIJ pain, being responded to SIJ block were enrolled. For a control group, patients matched for sex, age group, the number of fused level and fusion to sacrum were randomly selected. Patients were assessed radiologic parameters including lumbar lordosis, pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). To evaluate the sagittal sacropelvic morphology and balance, the ratio of PT/PI, SS/PI and PT/SS were analyzed. Results A total of 28 patients with SIJ pain and 56 patients without SIJ pain were assessed. Postoperatively, SIJ pain group showed significantly greater PT (p=0.02) than non-SIJ pain group. Postoperatively, PT/PI and SS/PI in SIJ pain group was significantly greater and smaller than those in non-SIJ pain group respectively (p=0.03, 0.02, respectively) except for PT/SS (p=0.05). SIJ pain group did not show significant postoperative changes of PT/PI and SS/PI (p=0.09 and 0.08, respectively) while non-SIJ pain group showed significantly decrease of PT/PI (p=0.00) and increase of SS/PI (p=0.00). Conclusion This study presents different sagittal sacropelvic morphology and balance between the patients with/without SIJ pain following lumbar fusion surgery. The patients with SIJ pain showed retroversed pelvis and vertical sacrum while the patients without SIJ pain have similar morphologic features with asymptomatic populations in the literature.

Surgical Outcomes of Anterior Cervical Fusion Using Deminaralized Bone Matrix as Stand-Alone Graft Material: Single Arm, Pilot Study

Objective To investigate the safety and efficacy of demineralized bone matrix (DBM) as a bone graft substitute for anterior cervical discectomy and fusion (ACDF) surgery. Methods Twenty consecutive patients treated with ACDF using stand-alone polyestheretherketone (PEEK) cages (Zero-P) with DBM(CGDBM100) were prospectively evaluated with a minimum of 6 months of follow-up. Radiologic efficacy was evaluated with a 6-point scoring method for osseous fusion using plain radiograph and computed tomogrpahy scans. Clinical efficacy was evaluated using the visual analogue scale (VAS), Owestry disability index (ODI), and short-form health questionnaire-36. The safety of the bone graft substitute was assessed with vital sign monitoring and a survey measuring complications at each follow-up visit. Results There were significant improvements in VAS and ODI scores at a mean 6-month follow-up. Six months after surgery, solid fusion was achieved in all patients. Mean score on the 6-point scoring system was 5.1, and bony formation was found to score at least 4 points in all patients. There was no case with implant-related complications such as cage failure or migration, and no complications associated with the use of CGDBM100. Conclusion ACDF using CGDBM100 demonstrated good clinical and radiologic outcomes. The fusion rate was comparable with the published results of traditional ACDF. Therefore, the results of this study suggest that the use of a PEEK cage packed with DBM for ACDF is a safe and effective alternative to the gold standard of autologous iliac bone graft.

Minimally Invasive Transforaminal Lumbar Interbody Fusion Using Banana-Shaped and Straight Cages: Radiological and Clinical Results from a Prospective Randomized Clinical Trial

BACKGROUND In minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), cage type and position play important roles in fusion achievement and sagittal alignment correction. However, no prospective randomized comparison of the results using different types of cage has been reported to date. OBJECTIVE To compare the radiological and clinical outcomes of unilateral MIS-TLIF using 2 types of cage. METHODS All candidates for single-level MIS-TLIF were randomized into banana-shaped cage and straight-cage groups. Plain radiographs and computed tomography scans were used for assessment of cage positions, fusion status, disc height, segmental lordotic angle, cage subsidence, and pelvic parameters. Clinical outcome was assessed using visual analog scale and Oswestry Disability Index scores. RESULTS Forty-four and 40 consecutive patients were operated on using banana-shaped and straight cages, respectively. Cage position was more anterior and lateral in the straight-cage group and more medial and posterior in the banana-shaped cage group. Solid fusion was achieved in 95.2% and 96.6% of the 2 groups, respectively, at 12 mo. The change in disc height and segmental lordotic angle postoperatively was significantly greater in the banana-shaped cage group. The incidence of subsidence during follow-up was significantly higher in the banana-shaped cage group (P < .04). Clinically, the visual analog scale and Oswestry Disability Index scores decreased significantly after surgery in both groups, with no significant difference between the groups. CONCLUSION Our preliminary outcomes suggest that the subsidence rate may be higher using banana-shaped cages in MIS-TLIF, possibly due to their more medial final position.

Cystic Giant Sacral Schwannoma Mimicking Aneurysmal Bone Cyst : A Case Report and Review of Literatures

To present a rare case of a cystic giant schwannoma of the sacrum mimicking aneurysmal bone cyst (ABC). A 54-year-old man visited our institute complaining left leg weakness and sensory change for several years. Magnetic resonance imaging revealed a large multilocular cystic mass with canal invasion and bone erosion confined to left S1 body. The lesion showed multiple septal enhancement without definite solid component. Initially the tumor was considered as ABC. The patient underwent grossly-total tumor resection with lumbosacral reconstruction via posterior approach. The tumor was proved to be a cystic schwannoma. The postoperative course was uneventful and the patient was relieved from preoperative symptoms. We present a rare case of pure cystic giant schwannoma confined to sacrum mimicking ABC. The surgical treatment is challenging due to the complex anatomy of the sacrum. Schwannoma should be considered in the differential diagnosis of osteolytic sacral cysts.

Unrecognized Shoulder Disorders in Treatment of Cervical Spondylosis Presenting Neck and Shoulder Pain

Objective Cervical spondylosis and shoulder disorders share with neck and shoulder pain. Differentiating between the two can be challenging and patient with combined pathologies is less likely to have pain improvement even after successful cervical operation. We investigated clinical characteristics of the patients who were diagnosed as cervical spondylosis however, were turned out to have shoulder disorders or the patients whose pain was solely originated from shoulder. Methods Between January 2008 and October 2009, the patients presenting neck and shoulder pain with diagnosis of cervical spondylosis were enrolled. Among them, the patients who met following inclusion criteria were grouped into shoulder disorder group and the others were into cervical spondylosis group. Inclusion criteria were as follows. (1) To have residual or unresponsive neck and shoulder pain despite of optimal surgical treatment due to concomitant shoulder disorders. (2) When the operation was cancelled for the reason that shoulder and neck pain was proved to be related with unrecognized shoulder disorders. The authors retrospectively reviewed and compared clinical characteristics, level of pathology, diagnosis of cervical spondylosis and shoulder disorders. Results A total of 96 patients were enrolled in this study. Shoulder disorder group was composed of 15 patients (15.8%) and needed additional orthopedic treatment. Cervical spondylosis group was composed of 81 patients (84.2%). There was no significant differences in mean age, sex ratio and major diagnosis in both shoulder disorder and cervical spondylosis group (p=0.33, 0.78, and 0.68 respectively). However, the distribution of pathologic levels was found to be significantly different (p=0.03). In shoulder disorder group, the majority of lesions (15 of 19 levels, 78.9%) were located at the level of C4-5 (36.8%) and C5-6 (42.1%). On the other hand, in cervical spondylosis group, C5-6 (39.0%) and C6-7 (37.1%) were the most frequently observed level of lesions (80 of 105 levels, 16.1%). Conclusion It is very important for spine surgeons to perform a complete history taking and physical examination using the special tests, and to discover the underlying shoulder disorders causing of symptom in treatment of cervical spondylosis presenting neck and shoulder pain.

Endoscopic Radiofrequency Ablation of the Sacroiliac Joint Complex in the Treatment of Chronic Low Back Pain: A Preliminary Study of Feasibility and Efficacy of a Novel Technique

Background. Radiofrequency ablation (RFA) is a less invasive technique for treatment of sacroiliac joint (SIJ) pain. Objective. To evaluate the feasibility and efficacy of endoscope-guided RFA for the treatment of CLBP from the SIJ complex. Methods. In this retrospective study, the medical records of 17 patients who underwent endoscope-guided RFA of the SIJ complex were reviewed. A bipolar radiofrequency probe was used to lesion the posterior capsule of the SIJ as well as the lateral branches of S1, S2, S3, and the L5 dorsal ramus in multiple locations. We visualized the ablation area using endoscope. We assessed visual analogue scale (VAS) and the Oswestry disability index (ODI) preoperatively, immediately postop, and at 1-, 3-, and 6-month postop outpatient clinic visits. Patient satisfaction of the procedure was assessed in percentages. Results. The mean duration of operation was 20 to 50 minutes. The mean VAS and the ODI scores decreased significantly immediately after the procedure and were kept significantly lower than baseline levels during the follow-up periods. No complications occurred perioperatively and during the follow-up periods. 88.6% of patients were satisfied with the procedure. Conclusions. Our preliminary results suggest that endoscope-guided RFA may be alternative option to treat CLBP secondary to SIJ complex.

Correction to: Outcomes of oblique lateral interbody fusion for degenerative lumbar disease in patients under or over 65 years of age

In the original publication of this article [1] is an error in the Results section in the first paragraph in regards to a patient value introduced.

Clinical Outcomes of Minimally Invasive Posterior Cervical Decompression Using a Tubular Retractor for the Treatment of Cervical Spondylotic Myelopathy: Single-center Experience with a Minimum 12-month Follow-up

Objective: Recently, with the use of the tubular retractor system, minimally invasive posterior cervical decompression has become possible. Improvement of surgical technique has made reduction in tissue damage during operation possible, which allows less postoperative pain, and shorter hospital stays. The objective of this study is to evaluate the safety and efficacy of a minimally invasive surgical technique using a tubular retractor system. This study is a series of consecutive mid-term follow-up reports in controlled clinical trials held at the institute of the authors using a minimally invasive surgical technique. Methods: Twenty-one patients underwent minimally invasive posterior cervical decompression. Medical records including demographic data, diagnoses, complications, and degrees of symptom relief, were recorded and evaluated. Clinical outcomes were assessed by the neurological status and visual analog scale (VAS) score for neck and arm pain. Results: Muscle weakness improved in all patients, of whom 80.9% (17/21) showed a complete resolution of sensory deficits and 19.1% (4/21) showed partial improvement. An analysis of the mean VAS and Neck Disability Index scores revealed significant improvement at the final follow-up. The mean Japanese Orthopedic Association scoring system for cervical myelopathy (C-JOA score) scores also improved from a preoperative value of 11.2±2.6 to 16.2±3.1 for the last follow-up. The recovery rate calculated using the Hirabayashi method was shown to have an average of 53.2±22.0%. Conclusion: Our short-term experiences with relatively good clinical outcomes imply that this minimally invasive technique is a valid alternative option for the treatment of cervical spondylotic myelopathy.