Comparative study of two spinous process (SP) osteotomy techniques for posterior decompression surgery in lumbar spinal stenosis: SP base versus splitting osteotomy.

PURPOSE: To compare the postoperative clinical and radiological outcomes of the SP base osteotomy versus SP splitting techniques for PD for treating LSS. METHODS: Of 139 patients who underwent PD surgery for LSS, 97 who met the study criteria were enrolled in the study. Group A comprised 53 patients who underwent SP base osteotomy, and group B included 44 patients who underwent SP splitting osteotomy. The primary study endpoint was intensity of lower back pain (LBP) and pain radiation to the lower extremities measured with the visual analogue scale (VAS). Secondary endpoints included (1) clinical outcomes assessed using Oswestry disability index and 12-short health form questionnaire; (2) surgical outcomes; and (3) procedure-related complications. RESULTS: LBP was more or less greater in SP base osteotomy group than in SP splitting osteotomy group at postoperative 1 week and 1 year (P = 0.04 and 0.03), but radiating pain was no significant difference between the groups throughout the 1-year follow-up period. One year after the surgery, the fusion rate at the osteotomized site was significantly greater in SP splitting osteotomy group (77%) than in SP base osteotomy group (55%) (P = 0.03). Clinical outcomes, surgical outcomes, and complications did not differ significantly between groups during follow-up times. CONCLUSIONS: The two SP osteotomy techniques offer excellent clinical and radiological outcomes at least for the first year after the surgery. In fusion rate at the osteotomized SP site, the SP splitting technique was superior to the SP base osteotomy technique. These slides can be retrieved under Electronic Supplementary Material.

Platelet-Rich Plasma Increases the Levels of Catabolic Molecules and Cellular Dedifferentiation in the Meniscus of a Rabbit Model.

Despite the susceptibility to frequent intrinsic and extrinsic injuries, especially in the inner zone, the meniscus does not heal spontaneously owing to its poor vascularity. In this study, the effect of platelet-rich plasma (PRP), containing various growth factors, on meniscal mechanisms was examined under normal and post-traumatic inflammatory conditions. Isolated primary meniscal cells of New Zealand white (NZW) rabbits were incubated for 3, 10, 14 and 21 days with PRP(-), 10% PRP (PRP(+)), IL(+) or IL(+)PRP(+). The meniscal cells were collected and examined using reverse-transcription polymerase chain reaction (RT-PCR). Culture media were examined by immunoblot analyses for matrix metalloproteinases (MMP) catabolic molecules. PRP containing growth factors improved the cellular viability of meniscal cells in a concentration-dependent manner at Days 1, 4 and 7. However, based on RT-PCR, meniscal cells demonstrated dedifferentiation, along with an increase in type I collagen in the PRP(+) and in IL(+)PRP(+). In PRP(+), the aggrecan expression levels were lower than in the PRP(-) until Day 21. The protein levels of MMP-1 and MMP-3 were higher in each PRP group, i.e., PRP(+) and IL(+)PRP(+), at each culture time. A reproducible 2-mm circular defect on the meniscus of NZW rabbit was used to implant fibrin glue (control) or PRP in vivo. After eight weeks, the lesions in the control and PRP groups were occupied with fibrous tissue, but not with meniscal cells. This study shows that PRP treatment of the meniscus results in an increase of catabolic molecules, especially those related to IL-1α-induced inflammation, and that PRP treatment for an in vivo meniscus injury accelerates fibrosis, instead of meniscal cartilage.

Time-sequential modulation in expression of growth factors from platelet-rich plasma (PRP) on the chondrocyte cultures.

Platelets are involved in hemostasis, wound healing, and tumor growth. Autologous blood products are commonly used to facilitate healing in a variety of clinical surgery applications. Recently, it was shown that platelet-rich plasma (PRP) has more specific growth factors that participate in the healing process. This study investigated the expression of PRP growth factors and evaluated their potential role in the cartilage regeneration using primary isolated chondrocytes. PRP obtained from New Zealand White rabbit by low speed centrifugation. Extracted PRPs contained 6-10 × 10(6) platelet/µl and concentration of platelets was slightly variable. Primary isolated chondrocytes from the same rabbits were cultured and treated with 0.1-20% PRP. The cells were collected and examined by reverse transcription-polymerase chain reaction and cytochemical staining. The expression of sex determining region Y-box 9, transforming growth factor-beta, vascular endothelial growth factor, and chondromdulin-I was increased in chondrocyte cultures with 10% PRP by time-dependent manner. To maintain the integrity of the cartilage, the proteoglycan contents were also up-regulated from the mRNA of aggrecan and positive Safranin-O staining in PRP concentration- and time-dependent manner. PRP provides crucial growth factors related to chondrocyte proliferation and differentiation through time-sequential modulation. Controlled in vivo trials for cartilage regeneration are needed.

Combined Anterior-Posterior Fusion Versus Posterior Alone Fusion for Cervical Myelopathy in Athetoid-Cerebral Palsy.

STUDY DESIGN: Retrospective comparative study. OBJECTIVES: Although some studies have discussed the use of lateral mass screws (LMSs) in patients with cerebral palsy (CP), it is unclear whether posterior LMS fixation alone is a suitable method. We aimed to compare the clinical, radiological, and surgical outcomes of 2 surgical modalities, namely, combined anterior-posterior (A-P) instrumented fusion and posterior fusion alone, in athetoid-type CP patients with cervical myelopathy (CM). METHODS: We analyzed 63 patients with athetoid-CP and CM who underwent posterior fusion only with LMS (group A, 35 patients) and A-P fusion (group B, 28 patients). The primary outcome was the 1- and 3-year fusion rates for the surgical segments. The secondary outcomes included the clinical outcomes based on pain intensity determined using the visual analog scale score, neck disability index, and 17-point Japanese Orthopedic Association score, radiological, and surgical outcomes. RESULTS: Fusion was achieved at 3 years postoperatively in 22 of 35 patients (63%) in group A and in 26 of 28 patients (93%) in group B (P = 0.02). The posterior neck pain intensity was also significantly lower in group B than in group A 2 and 3 years postoperatively (P = 0.02 and 0.01, respectively). The incidence of screw loosening and implant-related problems was higher in group A (60%) than in group B (21%) (P = 0.01). The other clinical and radiological parameters were similar between the groups. CONCLUSIONS: For athetoid CP-induced CM, combined A-P fusion would result in superior clinical and radiological outcomes compared to posterior fusion alone.

Optimal supplementation of dexamethasone for clinical purposed expansion of mesenchymal stem cells for bone repair.

BACKGROUND: Although mesenchymal stem cells (MSCs) are generally considered to represent a very promising tool for bone repair, no optimal protocol has yet been developed for the isolation and expansion of these cells for large-scale clinical applications. METHODS: Mesenchymal stem cells were supplemented with four different concentrations of dexamethasone: 0 M (Con), 0.2 × 10(-8) M (D0.2), 1.0 × 10(-8) M (D1.0) and 5.0 × 10(-8) M (D5.0); and analyzed every week for 5 weeks (P1-P5). Cells were analyzed via an alkaline phosphatase assay, DNA quantification, Oil Red stain, and flow cytometry for CD105 and CD90. Additionally, P3 and P5 cells were subcutaneously transplanted into nude mice after seeding in ceramic cubes. RESULTS: Proliferation of the cells was significantly higher in the D0.2 group. Alkaline phosphatase activities remained at low levels in the Con and D0.2 groups, but increased to high levels in the D1.0 and D5.0 groups as time elapsed. CD105 expression at P5 was lower than at P1, P2 and P3. Adipocyte differentiation was highest at P3. At the 8th week, in vivo bone formation was enhanced by the MSCs in a dexamethasone-supplemented culture for 3 or 5 weeks, and D0.2 was also higher than Con. CONCLUSIONS: The supplementation of MSCs under low-level rather than physiological concentrations (2 × 10(-9) M) of dexamethasone facilitates the culture expansion of these cells for osteogenic purposes by enhancing cell proliferation without diverse differentiation, and also promotes bone formation after in vivo transplantation.

The impact of posterior epidural adipose tissue on postoperative outcomes after posterior decompression surgery for lumbar spinal stenosis: A prospectively randomized non-inferiority trial.

STUDY DESIGN: The present study is a prospectively randomized study. OBJECTIVE: The objective of the study was to evaluate the impact of posterior epidural adipose tissue (PAT) on postoperative outcome following lumbar decompression surgery for lumbar spinal stenosis (LSS) by whether PAT was removed or preserved during the surgical procedure. SUMMARY OF BACKGROUND DATA: In posterior decompression surgery for LSS, PAT is routinely removed without knowledge of its role and significance. However, considering adipose tissue has regenerative properties of damaged neighboring tissues or itself, PAT, which is adipose tissue located at peridural space, might also have a potential to regenerate the neighboring damaged tissue, including dura and nerve root in the lumbar spine, but this has not been thoroughly studied. METHODS: Of the 185 eligible patients screened for the current study, 181 patients were enrolled and randomly allocated into either group A (PAT removal, n = 90) or group B (PAT retention, n = 91). The primary outcome measure was pain intensity on the lower back and lower extremity. The secondary outcome measures were functional outcome based on the Oswestry disability index (ODI) and walking distance, complications during the surgical procedure, and surgical outcomes. RESULTS: Postoperative pain intensity on the lower back and lower extremity was greater in group A than in group B. Functional status on ODI and walking distance was also worse in group B than in group A (64.9% in group A and 66.2% in group B). The number of patients with aggravated pain intensity and deteriorated functional status in postoperative follow-up times was significantly greater in group A than in group B. There were no significant differences in surgical outcome and complications between the groups. CONCLUSION: Preserving epidural fat may be favorable in postoperative outcomes of posterior decompression surgery for LSS compared to removing epidural fat.

AMPK activator, AICAR, inhibits palmitate-induced apoptosis in osteoblast.

Osteoblast apoptosis reduces bone mineral density. Apoptosis can be induced in a variety of cells by palmitate, which is one of the most common saturated fatty acids in dietary fat. The AMPK activator, AICAR, has been shown to inhibit palmitate-induced apoptosis. However, the role of palmitate in osteoblast apoptosis is currently unknown. This study examined whether palmitate could induce apoptosis in osteoblasts, and if so, whether AICAR could alleviate palmitate-induced apoptosis. Palmitate reduced cell survival and induced apoptosis in a dose- and time-dependent manner in human fetal osteoblasts (hFOB) 1.19. While the long-chain acyl-CoA synthetase inhibitor, triacsin C, inhibited palmitate-induced apoptosis, anti-oxidants and ceramide synthesis inhibitors did not attenuate the apoptosis. AICAR prevented palmitate-induced apoptosis and the inhibition of AICAR-mediated increase in fatty acid oxidation by etomoxir did not affect the prevention of apoptosis by AICAR. Constitutively-active AMPK also inhibited palmitate-induced apoptosis. Treatment with an AMPK inhibitor (compound C) and a dominant-negative AMPK adenovirus suppressed the inhibitory effect of AICAR on apoptosis. Palmitate impaired the activation of ERK by fetal bovine serum, which was blocked by AICAR. Moreover, AICAR increased ERK activation, and ERK inhibitors, PD98059 and U0126, as well as a dominant-negative MEK1, abolished the inhibitory effect of AICAR on palmitate-induced apoptosis. AICAR also inhibited palmitate-induced apoptosis in osteoblastic differentiated cells from human bone marrow, which was accompanied by recovered ERK activity. These results suggest that palmitate induces apoptosis in osteoblasts through the impaired activation of ERK, and the activation of AMPK inhibits palmitate-induced apoptosis by activating ERK.

Effect of different bone substitutes on the concentration of growth factors in platelet-rich plasma.

This study is conducted to determine the effect of different kinds of bone substitutes and collagen on the concentration of platelet-derived growth factor (PDGF) and transforming growth factor beta-1 (TGF beta-1) in platelet-rich plasma (PRP). PRP is treated with thrombin, hydroxyapatite (HA), and thrombin, HA alone, collagen-grafted HA, calcium metaphosphate (CMP), and collagen-grafted CMP. The concentrations of PDGF-AB and TGF beta-1 are measured. After PRP treated with HA and CMP, the concentrations of PDGF and TGF beta-1 are not significantly different from the concentration of them in PRP alone. The concentrations of PDGF in PRP with collagen-grafted HA and collagen-grafted CMP are significantly higher than that of PRP with HA and CMP. The concentrations of PDGF and TGF beta-1 in PRP with collagen-grafted CMP are higher than with collagen-grafted HA. The results of multiple regression analysis show that PDGF increased with the use of collagen and thrombin, and is higher in native whole blood with higher platelet counts. However, PDGF decreased with the use of HA. In conclusion, HA and CMP do not seem to be able to activate platelets by themselves. However, if they had collagen grafted onto them, they could activate platelets and release growth factors.

Comparative Study of Cortical Bone Trajectory-Pedicle Screw (Cortical Screw) Versus Conventional Pedicle Screw in Single-Level Posterior Lumbar Interbody Fusion: A 2-Year Post Hoc Analysis from Prospectively Randomized Data.

OBJECTIVE: The aim of this study was to report 2-year follow-up outcomes of posterior lumbar interbody fusion (PLIF) with cortical bone trajectory-pedicle screw (CS), in terms of fusion rates, clinical outcomes, surgical outcomes, and complications, and to compare these outcomes with outcomes for PLIF with conventional pedicle screw (PS). METHODS: We enrolled 79 patients and randomly assigned them to 2 groups (group A with PS, 39 patients; group B with CS, 40 patients), and finally 37 and 35 in group A and B were analyzed in the study. The primary outcome measure was the fusion rate, evaluated by dynamic radiographs and computed tomography scans. Secondary outcome measures included 1) patient satisfaction; 2) clinical outcomes measured with pain intensity using a visual analog scale, the Oswestry Disability Index, and 12-Item Short Form Health Survey; 3) radiologic outcomes; and 4) complications. RESULTS: At 2-year follow-up, the fusion rate was comparable between the PS and CS groups (35 of 37 patients in the PS group; 32 of 35 patients in the CS group; P > 0.99). The patient satisfaction rate at the 1-month follow-up was significantly greater in the CS group than in the PS group (P = 0.03); however, there was no significant difference between the groups at the 1-year and 2-year follow-ups. Clinical outcomes, radiologic outcomes, and related complications revealed no significant differences in both groups within 2 years postoperatively. CONCLUSIONS: We suggest that CS in single-level PLIF may be an alternative to PS.

The Impact of L5 Sacralization on Fusion Rates and Clinical Outcomes After Single-level Posterior Lumbar Interbody Fusion (PLIF) at L4-L5 Level.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To determine the impact of L5 sacralization on fusion rates and clinical outcomes after single-level posterior lumbar interbody fusion (PLIF) surgery at the L4-L5 level. SUMMARY OF BACKGROUND DATA: L5 sacralization can produce greater stress concentration at the adjacent segment (L4-L5); therefore, L4-L5 PLIF surgery in patients with L5 sacralization may negatively affect fusion rate and be associated with poor clinical outcomes. However, no study has examined the impact of L5 sacralization on fusion rates and clinical outcomes of patients who undergo L4-L5 PLIF surgery. MATERIALS AND METHODS: Of 153 patients who underwent L4-L5 PLIF, data of 145 who met the study criteria were retrospectively reviewed. Among them, 31 patients had L5 sacralization (group A), whereas the remaining 114 patients did not (group B). The primary study endpoint was fusion rate evaluated using dynamic radiographs and computed tomographic scans. Secondary endpoints included (1) pain intensity in the lower back and radiating to the lower extremities on the visual analog scale; (2) clinical outcomes assessed using the Oswestry Disability Index and 12-item Short Form Health Survey; (3) surgical outcomes; and (4) complications. RESULTS: Fusion rate evaluated using dynamic radiographs and computed tomographic scans at 6 months after surgery did not differ significantly between patients with and without sacralization (P=0.70 and 0.81, respectively), whereas fusion rate at 1 year after surgery did (P=0.04 and 0.04, respectively). In particular, patients with type II or III L5 sacralization had significantly lower fusion rates than those with other types of or no L5 sacralization. Pain intensity, clinical and surgical outcomes, and complications did not differ significantly between groups. CONCLUSIONS: Patients with type II or III L5 sacralization may have worse fusion rates after L4-L5 PLIF surgery than those with type I or no sacralization.

Effect of water glass coating of tricalcium phosphate on in vitro cellular proliferation and osteogenic differentiation.

Background In this study, the properties of the water glass (WG, sodium-silicate glass) were utilized to control the biodegradability of the beta tricalcium phosphate materials by the WG coating on the tricalcium phosphate disc surface with various coating thickness, chemistry, and heat-treatment. Methods Four types of disc specimens were prepared. A sample group A consisted of pure hydroxyapatite (HA) as a negative resorption control; a sample group B consisted of pure beta tricalcium phosphate as a positive resorption control; a sample group C consisted of beta tricalcium phosphate coated with WG as an early resorption model; and a sample group D consisted beta tricalcium phosphate coated with WG and heat-treated at 500°C as a delayed resorption model. Using human bone marrow-derived mesenchymal stem cells, for the analysis of cellular attachment and proliferative activity, 4-6-Diamidino-2-Phenylindole fluorescence technique was used. For the analysis of osteteogenic differentiation, alkaline phospastase (ALP) activity was measured. Results The mean z-scores of four groups (A, B, C, and D) in cellular attachment at 4 h after seeding were -1.21, -0.15, 0.42, and 0.94, respectively, and statistically significantly different in all groups respectively. Seven days after seeding, the mean z-scores of cellular proliferation were 1.97, 0.71, 1.48, and 1.83 in the four groups, respectively. The mean z-scores of the ALP activity per the mean z-scores of cell numbers of respective groups on the seventh day were 0.40, -1.51, 0.12, and 0.06, respectively, in four groups. Conclusion Initial cellular attachment is better on beta tricalcium phosphate than on HA and is enhanced by WG coating, especially with sintering at the high temperature. Cellular proliferation is considered to be increased by maintaining its attachment site through reduced dissolution of beta tricalcium phosphate by WG coating. Osteogenic differentiation in in-vitro study on the WG-coated beta tricalcium phosphate is thought to be as the result of increased silicon ion release from the WG.

Effect of water glass coating of tricalcium phosphate granules on in vivo bone formation.

BACKGROUND: Recently, some authors introduced a water glass (WG, sodium-silicate glass; Na2O·SiO2·nH2O) coating over tricalcium phosphate (TCP) bioceramic to modulate its resorption rate and enhance the bone cell behaviors. In this study, four different types of granular samples were prepared to evaluate the ability of new bone formation in vivo using micro-computed tomography and histology. METHODS: Four types sample groups: group A (pure HA as a negative resorption control); group B (pure TCP as a positive resorption control); group C (WG-coated TCP as an early resorption model); and group D (same as group C but heat-treated at 500°C as a delayed resorption model). Cylindrical tube-type carriers with holes were fabricated with HA by extrusion and sintering. Each carrier was filled densely with each granular sample. Four types of tubes were implanted into the medial femoral condyle and medial tibial condyle of New Zealand White rabbits. RESULTS: The HA group (A) showed the lowest amount of new bone formation. All the TCP sample groups (B, C, and D) showed more new bone formation. On the other hand, among the TCP groups, group C (early resorption model) showed slightly more bone formation. The amount of residual bioceramics was most abundant in the HA group (A). All the TCP sample groups showed less residual bioceramics than group A. Among the TCP groups, group C showed slightly more residual bioceramics. Group B showed the lowest amount of residual bioceramics. CONCLUSIONS: The WG-coated TCP sample (group C) is the best bone substitute candidate because of its proper biodegradation rate and the Si ions release because the WG-coated layer reduces the material resorption and enhances the new bone formation. That is, the WG-coated TCP is believed to be the best material for the application of an artificial bone substitute material.

The Efficacy of Vitamin C on Postoperative Outcomes after Posterior Lumbar Interbody Fusion: A Randomized, Placebo-Controlled Trial.

BACKGROUND: Vitamin C has critical features relavant to postoperative pain management and functional improvement; however, no study has yet evaluated the effectiveness of vitamin C on improving the surgical outcomes for spine pathologies. Thus, this study aimed to explore the impact of vitamin C on postoperative outcomes after single-level posterior lumbar interbody fusion (PLIF) for lumbar spinal stenosis in prospectively randomized design. We conducted a 1-year prospective, randomized, placebo-controlled, double-blind study to evaluate the impact of vitamin C on the postoperative outcomes after PLIF surgery. METHODS: A total of 123 eligible patients were randomly assigned to either group A (62 patients with vitamin C) or group B (61 patients with placebo). Patient follow-up was continued for at least 1 year after surgery. The primary outcome measure was pain intensity in the lower back using a visual analogue scale. The secondary outcome measures were: (1) the clinical outcome assessed using the Oswestry Disability Index (ODI); (2) the fusion rate assessed using dynamic radiographs and computed tomography scans; and (3) complications. RESULTS: Pain intensity in the lower back was significantly improved in both groups compared with preoperative pain intensity, but no significant difference was observed between the 2 groups over the follow-up period. The ODI score of group A at the third postoperative month was significantly higher than the score of group B. After the sixth postoperative month, the ODI score of group A was slightly higher than the score of group B; however, this difference was not significant. The fusion rates at 1 year after surgery and the complication rates were not significantly different between the 2 groups. CONCLUSIONS: Postoperative pain intensity, the primary outcome measure, was not significantly different at 1 year after surgery between the 2 groups. However, vitamin C may be associated with improving functional status after PLIF surgery, especially during the first 3 postoperative months.

Which Technique Is Better Option for C3 Segment in Multilevel Open-Door Laminoplasty of the Cervical Spine?: Laminectomy Versus Laminoplasty.

STUDY DESIGN: A post-hoc comparative study. OBJECTIVE: To evaluate postoperative clinical, radiological, and surgical outcomes after laminoplasty (LP) involving the C3 segment and to compare outcomes with those of patients who underwent LP with C3 laminectomy (LN). SUMMARY OF BACKGROUND DATA: In many of the pathologies that require LP involving C3 segment, most spine surgeons perform LP at C3 and other cervical segments. Considering the peculiarities of the C2-C3 level, spine surgeons should take into account those in LP involving the C3 segment, but the particular aspects of the C2-C3 levels have not been fully evaluated. METHODS: Of 93 patients, 66 patients (39 in group A, LP involving C3; 27 in group B, LP with C3 LN) were enrolled in the study. The primary outcome measure was pain intensity of the posterior neck measured with visual analog scale. Secondary endpoints included the following: (1) radiologic outcomes based on the cervical range of motion and rate of bony impingement and spontaneous fusion between C2 and C3, (2) clinical outcomes based on the 12-item short-form health survey and Japanese Orthopedic Association scale, and (3) surgical outcomes. RESULTS: The primary end-point of the present study, posterior neck pain, exhibited a greater improvement in the group with C3 LN than in the group with C3 LP at 6 months and 1 year after surgery (P = 0.03 and 0.01, respectively). The cervical range of motion of C3 LN group was significantly greater than C3 LP group at postoperative 1 year (P = 0.02). Radiologic evidences of bony impingement and spontaneous fusion between C2 and C3 were significantly greater in C3 LP group than in C3 LN group. Clinical outcomes and surgical outcomes did not differ significantly between groups. CONCLUSION: We recommend performing LN instead of LP for the C3 segment in cases requiring multilevel LP surgery involving C3. LEVEL OF EVIDENCE: 3.

Impact of wedge-shaped resection of the posterior bony arch on postoperative outcomes after open door laminoplasty in the cervical spine: a 2-year follow-up study.

BACKGROUND CONTEXT: Open door laminoplasty (ODLP) can also lead to significant postoperative motion restriction that further increases over time, for which one of the possible factors is the bony impingement between neighboring posterior bony arches. Previously, we reported this phenomenon and modified technique of ODLP, wedge-shaped resection of the posterior bony arch that produced greater range of motion (ROM) of the cervical spine and less posterior neck pain compared with conventional ODLP (cODLP) in 1-year follow-up time, but no longer follow-up outcomes of the surgical technique has been reported. PURPOSE: The study aimed to thoroughly evaluate the impact of posterior bony impingement following ODLP on postoperative cervical motion and related outcomes, and to compare postoperative outcomes of conventional ODLP (cODLP with those of modified ODLP (mODLP) in 2-year follow-up times. STUDY DESIGN: This is a retrospective comparative study. PATIENT SAMPLE: A total of 145 patients who underwent cODLP or mODLP and were followed up for at least 2 years were classified into two groups: Group A (cODLP, 79 patients) and Group B (mODLP, 66 patients). OUTCOME MEASURES: The primary outcome measure was ROM of the cervical spine. Secondary outcome measures included (1) patient satisfaction, (2) radiological outcomes, including the rate of bony impingement and spontaneous fusion, and bone regrowth of the resection site, (3) clinical outcomes based on pain intensity and scores on the 12-item short-form health survey (SF-12) and neck disability index (NDI), (4) surgical outcomes, and (5) surgery-related complications. METHODS: We compared baseline data in both groups. To evaluate the impact of our surgical modification on postoperative outcome after ODLP, we compared the outcome measures in 2-year follow-up times. No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript. RESULTS: The ROM of the cervical spine was significantly greater in Group B 2 years after surgery than in Group A (p=.001). Patient satisfaction (p=.02) at 2 years after surgery and pain intensity of the posterior neck at 1 (p=.01) and 2 years (p<.01) after surgery were better in Group B than in Group A. Radiological evidence of posterior bony impingement and spontaneous fusion between ODLPsegments were definitely fewer less in Group B than in Group A (p<.001 and<0.001, respectively). The mean value of bone regrowth was 1.2 mm (range, 0-3 mm). The NDI and SF-12 scores did not differ significantly between groups. Surgical outcomes and postoperative complications were similar between groups. CONCLUSIONS: These results indicate that posterior bony impingement can be a factor in ROM restriction after cODLP surgery and that wedge-shaped resection during ODLP can be a reliable option for preserving cervical ROM and improving postoperative clinical and radiological outcomes.

Wedge-Shaped Resection of the Posterior Bony Arch During Open Door Laminoplasty to Prevent Postoperative Motion Limitation.

STUDY DESIGN: Prospective randomized double-arm noninferiority study. OBJECTIVE: To evaluate an additional surgical procedure (wedge-shaped resection of the cranial portion of the posterior bony arch) during open-door laminoplasty (ODLP), and to compare the outcomes with those of conventional ODLP surgery. SUMMARY OF BACKGROUND DATA: In clinical practice, spine surgeons sometimes encounter patients who show bony impingement on lateral radiographs after ODLP; bony impingement may lead to reduced motion of the cervical spine and posterior neck pain. However, this problem has not been well studied, and no methods have been developed to prevent it. METHODS: Of total 79 patients, 75 were enrolled and randomly assigned to either group A (additional procedure in ODLP, n = 38) or group B (ODLP alone, n = 37). The primary outcome measure was range of motion (ROM) of the cervical spine. Secondary endpoints included clinical outcomes based on pain intensity, 12-item short form health survey (SF-12), and modified Japanese Orthopedic Association scale; presence of bony impingement on dynamic lateral radiographs; surgical outcomes; and surgery-related complications. RESULTS: ROM of the cervical spine was significantly greater at 6 months (P = 0.04) and 1 year (P = 0.02) postoperative in group A than in group B. Pain intensity at the posterior neck was significantly lower 1 year after surgery in group A than in group B (P = 0.03). In lateral radiographs 1 year after surgery, the presence of posterior bony impingement was 0% in group A and 32.4% in group B (P <0.01). Clinical outcomes and surgery-related complications were similar between groups. CONCLUSION: Performing wedge-shaped resection of the cranial portion of the posterior bony arch in ODLP surgery can lead to better outcomes than ODLP alone in terms of preservation of cervical ROM, prevention of posterior bony impingement, and amelioration of posterior neck pain. LEVEL OF EVIDENCE: 2.

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.

Usefulness of K-Point Injection for the Nonspecific Neck Pain in So-Called K-Point Syndrome.

BACKGROUND: Shoichi Kokubun introduced his successful experience with local anesthetic injection at the occipital insertion of the sternocleidomastoid muscle in K-point syndrome. The purpose of this study was to evaluate the short-term and long-term effectiveness of K-point injection and investigate factors affecting treatment results. METHODS: K-point injection was performed in 58 patients with K-point syndrome at Yeungnam University Medical Center. The syndrome was associated with cervical whiplash injury in 10 patients and was of nonspecific origin in the rest. One milliliter of 2% lidocaine mixed with 1 milliliter of dexamethasone was injected in 50 patients and 2 milliliters of 1% lidocaine alone in the rest. Initially, the severity of local tenderness at the K-point and other tender points was examined and the degree of immediate pain relief effect was assessed within 1 hour after injection. Early effect within 1 month after the injection and current effect were evaluated in 27 patients using a modified Kim's questionnaire with regard to the duration of improvement, degree of improvement in pain and daily living activities, and satisfaction. RESULTS: Of the total 58 patients, 44 (75.8%) apparently had immediate pain relief after K-point injection. The only factor associated with successful immediate pain relief was the whiplash injury associated with traffic accident (TA). The early pain control effect was associated with the immediate effect. The current effect was associated with the early effect alone. Satisfaction with the K-point injection was related to early successful pain relief. CONCLUSIONS: K-point injection would be useful for early pain relief in nonspecific neck pain syndrome so called K-point syndrome, but not for current pain relief. Especially, it was very effective for early pain control in the whiplash injury associated with TA.

Significance of Coronal Proset Magnetic Resonance Imaging to Detect Hidden Zone of the Mid-Zone Stenosis in the Lumbar Spine and Morphometric Analysis of the Mid-Zone Stenosis.

STUDY DESIGN: Retrospective exploratory imaging study. PURPOSE: To investigate the significance of the coronal magnetic resonance imaging (MRI) using Proset technique to detect the hidden zone in patients with mid-zone stenosis by comparing with conventional axial and sagittal MRI and to explore the morphologic characteristic patterns of the mid-zone stenosis. OVERVIEW OF LITERATURE: Despite advancements in diagnostic modalities such as computed tomography and MRI, stenotic lesions under the pedicle and pars interarticularis, also called the mid-zone, are still difficult to definitely detect with the conventional axial and sagittal MRI due to its inherited anatomical peculiarity. METHODS: Of 180 patients scheduled to undergo selective nerve root block, 20 patients with mid-zone stenosis were analyzed using MRI. Characteristic group patterns were also explored morphologically by comparing MRI views of each group after verifying statistical differences between them. Hierarchical cluster analysis was performed to classify morphological characteristic groups based on three-dimensional radiologic grade for stenosis at all three zones. RESULTS: At the mid-zone, the stenosis of grade 2 or more was found in 14 cases in the coronal image,13 cases in the sagittal image, and 9 cases in the axial image (p<0.05). Especially, mid-zone stenosis was not detected in six of 20 cases at the axial images. At the entrance and exit-zone, coronal image was also associated with more accurate detection of hidden zone compared to other views such as axial and sagittal images. After repeated statistical verification, the morphological patterns of hidden zone were classified into 5 groups: 6 cases in group I; 1 case in group II; 4 cases in group III; 7 cases in group IV; and 2 cases in group V. CONCLUSIONS: Coronal MRI using the Proset technique more accurately detected hidden zone of the mid-zone stenosis compared to conventional axial and sagittal images.

The impact of generalized joint laxity (GJL) on the posterior neck pain, cervical disc herniation, and cervical disc degeneration in the cervical spine.

BACKGROUND CONTEXT: Generalized joint laxity (GJL) can have a negative impact on lumbar spine pathology, including low back pain, disc degeneration, and disc herniation, but the relationship between GJL and cervical spine conditions remains unknown. PURPOSE: To investigate the relationship between GJL and cervical spine conditions, including the prevalence of posterior neck pain (PNP), cervical disc herniation (CDH), and cervical disc degeneration (CDD), in a young, active population. STUDY DESIGN: Retrospective 1:2 matched cohort (case-control) study from prospectively collected data PATIENT SAMPLE: Of a total of 1853 individuals reviewed, 73 individuals with GJL (study group, gruop A) and 146 without GJL (control group, Group B) were included in the study according to a 1:2 case-control matched design for age, sex, and body mass index. OUTCOME MEASURE: The primary outcome measure was the prevalence and intensity of PNP at enrollment based on a visual analogue scale score for pain. The secondary outcome measures were (1) clinical outcomes as measured with the neck disability index (NDI) and 12-item short form health survey (SF-12) at enrollment, and (2) radiological outcomes of CDH and CDD at enrollment. METHODS: We compared baseline data between groups. Descriptive statistical analyses were performed to compare the 2 groups in terms of the outcome measures. RESULTS: The prevalence and intensity of PNP were significantly greater in group A (patients with GJL) than in group B (patients without GJL) (prevalence: p=.02; intensity: p=.001). Clinical outcomes as measured with NDI and SF-12 did not differ significantly between groups. For radiologic outcomes, the prevalence of CDD was significantly greater in group A than in group B (p=.04), whereas the prevalence of CDH did not differ significantly between groups (p=.91). CONCLUSIONS: The current study revealed that GJL was closely related to the prevalence and intensity of PNP, suggesting that GJL may be a causative factor for PNP. In addition, GJL may contribute to the occurrence of CDD, but not CDH. Spine surgeons should screen for GJL in patientswith PNP and inform patients of its potential negative impact on disc degeneration of the cervical spine.