A New Technique for Lumbar Spondylolisthesis Reduction Using T-Shaped Tools.

STUDY DESIGN: Retrospective study. PURPOSE: To introduce a simple technique to facilitate lumbar spondylolisthesis reduction during posterior lumbar interbody fusion (PLIF). OVERVIEW OF LITERATURE: Spondylolisthesis reduction has been conducted in various ways, but most of them require special complicated tools. METHODS: T-shaped levering tool was newly designed. This study included 23 patients who underwent PLIF for lumbar spondylolisthesis treatment using newly designed T-shaped tools and followed up for >2 years. Demographic, clinical, and surgical data, which had been routinely collected in a database, were analyzed. The degree of listhesis was measured on lateral radiographs by the Taillard method. RESULTS: The authors could achieve lumbar spondylolisthesis reduction without difficulty using newly designed T-shaped tools. Immediate postoperative lateral radiographs revealed a reduced preoperative slip of 36.9%±9.6% to 1.2%±1.9%, showing a correction rate of 96.7%. The final follow-up radiographs revealed the mean final slip of 2.6%±2.7%, showing a correction rate of 93.0%. CONCLUSIONS: This technique allowed lumbar spondylolisthesis reduction without difficulty.

Bone Union Rate Following Instrumented Posterolateral Lumbar Fusion: Comparison between Demineralized Bone Matrix versus Hydroxyapatite.

STUDY DESIGN: Retrospective study. PURPOSE: To compare the union rate of posterolateral lumbar fusion (PLF) using demineralized bone matrix (DBM) versus hydroxyapatite (HA) as bone graft extender. OVERVIEW OF LITERATURE: To our knowledge, there has been no clinical trial to compare the outcomes of DBM versus HA as a graft material for PLF. METHODS: We analyzed prospectively collected data from consecutive 79 patients who underwent instrumented PLF. Patients who received DBM were assigned to group B (n=38), and patients who received HA were assigned into group C (n=41). The primary study outcome was fusion rate assessed with radiographs. The secondary outcomes included pain intensity using a visual analogue scale, functional outcome using Oswestry disability index score, laboratory tests of inflammatory profiles and infection rate. RESULTS: One year postoperatively, bone fusion was achieved in 73% in group B and 58% in group C without significant difference between the groups (p=0.15). There were no differences between the groups with respect to secondary outcomes. CONCLUSIONS: DBM would provide noninferior outcomes compared to the HA as a fusion material for PLF, and could be a notable alternative.

Result of Modular Necks in Primary Total Hip Arthroplasty with a Average Follow-up of Four Years.

PURPOSE: This study aimed to investigate the outcomes of modular neck-utilization in primary total hip arthroplasty (THA). MATERIALS AND METHODS: Thirty patients (34 hips) who had modular stem THA between April 2011 and January 2013 were evaluated. There were 19 men and 11 women with a mean age of 61.2 years at the time of surgery. There were 20 cases of osteonecrosis of femoral head, 7 cases of osteoarthritis, 6 cases of femur neck fracture, and 1 case of rheumatoid arthritis. No patients presented with anatomical deformity of hip. Patients were operated on using a modified Watson-Jones anterolateral approach. All patients underwent clinical and radiological follow-up at 6 weeks, 3, 6, and 12 months, and every year postoperatively. The mean duration of follow-up was 48.2 months (range, 39 to 59 months). RESULTS: The average Harris hip score improved from 63.7 to 88.1 at the final follow-up. Radiographically, mean acetabular cup inclination was 45.3°(range, 36°-61°) and anteversion was 21.7°(range, 11°-29°). All were neutral-positioned stems except 5 which were varus-positioned stems. In only 3 cases (8.8%), varus or valgus necks were required. A case of linear femoral fracture occurred intraoperatively and 1 case of dislocation occurred at postoperative 2 weeks. No complications at modular junction were occurred. CONCLUSION: Our study shows that the use of modular necks had favorable clinical and radiographic results. This suggests that the use of modular neck in primary THA without anatomical deformity is safe at a follow-up of 39 months.

A Prospective Randomized Clinical Trial Comparing Bone Union Rate Following Anterior Cervical Discectomy and Fusion Using a Polyetheretherketone Cage: Hydroxyapatite/B-Tricalcium Phosphate Mixture versus Hydroxyapatite/Demineralized Bone Matrix Mixture.

STUDY DESIGN: Prospective randomized noninferiority trial. PURPOSE: To evaluate whether the union rate of anterior cervical discectomy and fusion (ACDF) using a polyetheretherketone (PEEK) cage filled with a mixture of hydroxyapatite (HA) and demineralized bone matrix (DBM) is inferior to that of a mixture of ß-tricalcium phosphate (ß-TCP) and HA. OVERVIEW OF LITERATURE: There have been no clinical trials investigating the outcomes of a mixture of HA and DBM in a PEEK cage in ACDF. METHODS: Eighty-five eligible patients were randomly assigned to group B (n=43), in which a PEEK cage with a mixture of HA and DBM was used, or group C (n=42), in which a PEEK cage with a mixture of HA and ß-TCP was used. The primary study endpoint was the fusion rate, which was assessed with dynamic radiographs and computed tomography (CT) scans. Secondary endpoints included pain intensity using a visual analogue scale, functional outcome using a neck disability index score, laboratory tests of inflammatory profiles, and the infection rate. RESULTS: Seventy-seven patients (38 in group B and 39 in group C) were included in the final analysis. One year postoperatively, bone fusion was achieved in 87% of group B patients and 87% of group C patients on dynamic radiographs, and 87% of group B patients and 72% of group C patients on CT scans (p=1.00 and 0.16, respectively). There were also no between-groups differences with respect to the secondary endpoints. CONCLUSIONS: A HA/DBM mixture inside a PEEK cage can provide noninferior outcomes compared to a HA/TCP mixture in ACDF.

Monitoring the quality of robot-assisted pedicle screw fixation in the lumbar spine by using a cumulative summation test.

STUDY DESIGN: Prospective randomized controlled trial. OBJECTIVE: The aim of this study was to monitor the quality control of robot-assisted pedicle screw fixation accuracy by using a cumulative summation (CUSUM) test at the initial stage of its application. SUMMARY OF BACKGROUND DATA: Although robot-assisted pedicle screw fixation reduces screw misplacement rates and provides critical support for minimally invasive surgical procedures, there have been no reports relating to the monitoring of quality control of the accuracy of this robot-assisted pedicle screw fixation procedure. METHODS: Patients with lumbar spinal stenosis scheduled to undergo surgery were randomly and equally assigned through 1:1 allocation to a robot-assisted minimally invasive posterior lumbar interbody fusion (Rom-PLIF) group or a conventional open posterior PLIF using freehand technique group. The accuracy of pedicle screw placement was evaluated using postoperative computed tomography. The primary outcome was the CUSUM analysis for monitoring the quality control of the accuracy of pedicle screw insertion between the Rom-PLIF and conventional open posterior PLIF using freehand technique groups. RESULTS: Of the 80 pedicle screws inserted in each group, 4 screws in the Rom-PLIF group, and 7 in the conventional open PLIF group, breached the pedicle. Of these 11 offending screws, 4 cases were categorized as grade B in the Rom-PLIF group, whereas 6 were grade B and 1 case was grade C in the Com-PLIF group, using the Gertzbein and Robbins classification. Throughout the monitoring period, there was no CUSUM test-derived indication that the quality of performance of the pedicle screw fixation procedure was inadequate in either group. CONCLUSION: First, this study demonstrates the adequacy of quality control of robot-assisted pedicle screw fixation even early in the application period based on the CUSUM analysis. Second, the CUSUM test can be a useful tool for monitoring of the quality of procedures related with spine surgery.

Distraction Arthrodesis of the C1-C2 Facet Joint with Preservation of the C2 Root for the Management of Intractable Occipital Neuralgia Caused by C2 Root Compression.

STUDY DESIGN: Prospective observational cohort study. OBJECTIVE: To compare the outcomes of our new technique, distraction arthrodesis of C1-C2 facet joint with C2 root preservation (Study group), to those of conventional C1-C2 fusion with C2 root transection (Control group) for the management of intractable occipital neuralgia caused by C2 root compression. SUMMARY OF BACKGROUND DATA: We are not aware of any report concerning C2 root decompression during C1-C2 fusion. MATERIALS AND METHODS: Inclusion criteria were visual analogue scale (VAS) score for occipital neuralgia 7 or more; C2 root compression at the collapsed C1-C2 neural foramen; and follow-up 12 months or more. The Study group underwent surgery with our new technique including (1) C1-C2 facet joint distraction and bone block insertion while preserving the C2 root; and (2) use of C1 posterior arch screws instead of conventional lateral mass screws during C1-C2 segmental screw fixation. The Control group underwent C2 root transection with C1-C2 segmental screw fixation and fusion. We compared the prospectively collected outcomes data. RESULTS: There were 15 patients in the Study group and 8 in the Control group. Although there was no significant difference in the VAS score for the occipital neuralgia between the 2 groups preoperatively (8.2 ± 0.9 vs. 7.9 ± 0.6, P = 0.39), it was significantly lower in the Study group at 1, 3, and 6 months postoperatively (P < 0.01, respectively). At 12 months, it was 0.4 ± 0.6 versus 2.5 ± 2.6 (P = 0.01). There was no significant difference in improvement in the VAS score for neck pain and neck disability index and Japanese Orthopedic Association recovery rate, which are minimally influenced by occipital neuralgia. CONCLUSION: Our novel technique of distraction arthrodesis with C2 root preservation can be an effective option for the management of intractable occipital neuralgia caused by C2 root compression.

Comparative study of the treatment outcomes of osteoporotic compression fractures without neurologic injury using a rigid brace, a soft brace, and no brace: a prospective randomized controlled non-inferiority trial.

BACKGROUND: The efficacy of brace application for the treatment of osteoporotic compression fractures remains unclear. The purpose of this study was to compare the treatment outcomes in patients with osteoporotic compression fractures with regard to whether the patients had no braces, rigid braces, or soft braces. METHODS: We randomly assigned sixty patients with acute one-level osteoporotic compression fractures within three days of injury to the no-brace, soft-brace, and rigid-brace groups through 1:1:1 allocation. The primary outcome was the baseline adjusted Oswestry Disability Index score at twelve weeks after compression fracture. The non-inferior margin of the Oswestry Disability Index was set at an average of 10 points. RESULTS: The baseline adjusted Oswestry Disability Index score at twelve weeks after compression fracture in the no-brace group was not inferior to that in the soft-brace or rigid-brace groups. The mean adjusted Oswestry Disability Index score was 35.95 points (95% confidence interval, 25.42 to 46.47 points) in the no-brace group and 37.83 points (95% confidence interval, 26.77 to 48.90 points) in the soft-brace group, with a difference of -1.88 points (95% confidence interval, -7.02 to 9.38 points) between the groups. Similarly, the mean adjusted Oswestry Disability Index score was 35.95 points (95% confidence interval, 25.42 to 46.47 points) in the no-brace group and 33.54 points (95% confidence interval, 23.79 to 43.29 points) in the rigid-brace group, with a difference of 2.41 points (95% confidence interval, -7.86 to 9.27 points) between the groups. During the follow-up assessment period, there was no significant difference among the groups for the overall Oswestry Disability Index scores (p = 0.260), visual analog scale for pain scores for back pain (p = 0.292), and anterior body compression ratios (p = 0.237). However, the Oswestry Disability Index scores and the visual analog scale scores for back pain significantly improved with time after the fractures (p < 0.001), and the body compression ratios significantly decreased with time in all three groups (p < 0.001). CONCLUSIONS: The Oswestry Disability Index scores for the treatment of compression fractures without a brace were not inferior to those with soft or rigid braces. Moreover, the improvement in back pain and progression of anterior body compression were similar among the three groups. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Translation, cross-cultural adaptation, and validity of the Korean version of the pain sensitivity questionnaire in chronic pain patients.

The purpose of this study was to translate pain sensitivity questionnaires (PSQ) into the Korean language, perform a cross-cultural adaption of the PSQ, and validate the Korean version of PSQ in patients with degenerative spinal disease. The PSQ was translated forward and backward, cross-culturally adapted by 2 independent translators, and approved by an expert committee. The final Korean version of the PSQ was tested on 72 patients with degenerative spinal disease. Test-retest reliability was evaluated for 60 patients (83%) who completed the second assessment in an interval of 4 weeks. The mean PSQ-minor, PSQ-moderate, and PSQ-total (standard deviation [SD]) were 5.40 (2.02), 6.46 (1.98), and 5.93 (1.93), respectively. The PSQ-total, PSQ-minor, and PSQ-moderate of the Korean version showed very good internal consistencies determined by the Cronbach's α of 0.926, 0.869, and 0.877, respectively. For convergent validity, the PSQ scores of the Korean version showed significant correlations with pain catastrophizing scale (PCS) (r = 0.377, P = 0.002; r = 0.365, P = 0.003; r = 0.362, P = 0.003 for PSQ-total, PSQ-minor, and PSQ-moderate of the Korean version, respectively). For test-retest reliability, the intraclass correlation coefficients were 0.782 for PSQ-total, 0.752 for PSQ-minor, and 0.793 for PSQ-moderate. In conclusion, the validated Korean version of PSQ is a transculturally equivalent, reliable, and valid tool to assess individual pain sensitivity.

Treatment of Intertrochanteric Fractures Using the Compression Hip Nail.

PURPOSE: To investigate the clinical and radiologic outcomes following treatment of intertrochanteric fractures using the Compression Hip Nail® (CHN), which has a sliding lag screw. MATERIALS AND METHODS: Twenty-eight cases of intertrochanteric fractures treated with CHN from November 2012 to October 2013 and followed-up for >6 months were included. The patient population consisted of 11 men and 17 women with a mean age of 75.2 years at the time of surgery. For the initial 11 cases, 10 mm sliding lag screws were used; the remaining 17 cases used 20 mm sliding lag screws. Clinical variables including operation time, amount of transfusion, weight-bearing start time, postoperative physical activity, and complications were investigated. The average sliding of lag screws and the average union were investigated radiologically at 3 and 6 months after surgery. RESULTS: In an analysis of 23 cases (exclusion of 3 cases of lag screw cutout and 2 cases of nonunion), 11 (48%) recovered their pre-injury activity level. In an analysis of 25 cases (exclusion of 3 cases of cutout), 17 (68%) and 23 (92%) showed radiological union at postoperative months 3 and 6, respectively. Seven complications were noted. Cutout of the lag screw and the lateral protrusion of barrels were significantly greater in the group with 10 mm sliding lag screws as compared to the group using 20 mm sliding lag screws. CONCLUSION: The use of CHN for the treatment of intertrochanteric fracture yielded poor results. However, results from patients in the 20 mm sliding lag screw group were better than for the 10 mm sliding lag screw group. Therefore, use of the 20 mm sliding lag screw is advisable.