Can prophylactic C4/5 foraminotomy prevent C5 palsy after cervical laminoplasty with and without posterior instrumented fusion with maximal expansion?

OBJECTIVE: To prospectively examine whether laminoplasty with maximal expansion induces C5 palsy, even with prophylactic bilateral C4/5 foraminotomy. METHODS: Thirty-five consecutive patients with cervical myelopathy underwent laminoplasty (n = 19: LP group) or posterior decompression and fusion (n = 16: PDF group) with maximal expansion. Prophylactic bilateral C4/5 foraminotomy was performed alternately in consecutive five patients undergoing each type of surgery. In each type of surgery, the first and third consecutive five patients did not undergo foraminotomy (NF subgroup: 20 patients), while the second and fourth consecutive five patients underwent foraminotomy (F subgroup: 15 patients). The widths between the gutters was equivalent to the diameter of the spinal canal, and an inclination angle of the lamina of approximately 90° was created during laminoplasty. The incidence and severity of postoperative C5 palsy were investigated. Patients with a manual muscle testing score for the deltoid muscle and/or biceps brachii muscle of ≤ 2 were diagnosed with severe palsy. RESULTS: The respective incidences of C5 palsy in the F and NF subgroups were 33% and 20% in the LP group and 50% and 20% in the PDF group. Severe palsy occurred in 67% and 0% of patients who had developed palsy in F and NF subgroups, respectively, in the LP group, and in 100% of patients in the PDF group. Furthermore, 40% of the patients with severe palsy took more than 6 months to recover. CONCLUSIONS: Laminoplasty with maximal expansion induced C5 palsy in both the LP and PDF groups, even with the addition of prophylactic bilateral C4/5 foraminotomy.

Short Monocortical Screws at C4-C6 Lateral Masses as Novel Mid-cervical Anchor in Cervical Laminoplasty with Instrumented Fusion: Surgical Outcomes Compared with C5 Pedicle Screws as Mid-cervical Anchor.

INTRODUCTION: This retrospective study compared rates of bony fusion and screw loosening after multilevel posterior decompression and fusion (PDF) with short monocortical screws (SMS) as a novel mid-cervical anchor versus C5 pedicle screws (PS) as a mid-cervical anchor. METHODS: We analyzed 15 consecutive patients who underwent C2-T1 PDF with C5 PS as mid-cervical anchor (PS group) and 18 consecutive patients who underwent the procedure with SMS at C4-C6 as mid-cervical anchor (SMS group). Radiological outcomes, including rates of bony fusion at each level and screw loosening, and clinical outcomes, including Japanese Orthopedic Association (JOA) score, neck pain, neck disability index (NDI), and EuroQol 5 Dimension (EQ-5D), were compared between groups. In the SMS group, screw perforation types and appropriate screw insertion procedure were also investigated. RESULTS: The fusion rate at C2/3 in the SMS group (56%) was significantly higher than that in PS group (13%; P = 0.0272). None of the patients had SMS loosening postoperatively. Clinical outcomes, including JOA score, neck pain, NDI, and EQ-5D, did not differ between the groups. In the SMS group, facet perforation was the most common type of perforation. The recommended direction for SMS insertion at C4-C6 was 35°-37° in the cranial direction and 25°-30° in the medial direction; the recommended screw length was 10 mm. CONCLUSIONS: SMS at C4-C6 was as effective as C5 PS as a mid-cervical anchor in PDF, according to clinical and radiological outcomes. The fusion rate at C2/3 in the SMS group was significantly higher than that in the PS group. There was no postoperative loosening of the C5 PS or C4-C6 SMS in either group.

Protecting Surgeons' Fingers from Radiation Exposure during Lumbosacral Selective Nerve Root Block.

INTRODUCTION: Fluoroscopy-guided selective nerve root block (SNRB) is useful for the diagnosis and treatment of nerve root pain. However, the procedure exposes the surgeon's hands to radiation. Therefore, the purpose of this randomized prospective study was to assess the radiation exposure per unit time of the surgeon's fingers during performance of a lumbosacral SNRB and to calculate the annual exposure time limits for four hand-protection methods. METHODS: We prospectively recruited patients scheduled for an SNRB and measured the radiation exposure using a ring-type passive radiation dosimetry device attached to the distal phalanx of the index finger of the hand performing the needle placement. Patients were randomly divided into the following four groups: a) the direct exposure group, b) the 0.03-mmPb glove group, c) the 0.25-mmPb glove group, and d) the forceps group (in which the needle was held using forceps such that the fingers did not enter the irradiation field). RESULTS: We recruited 40 consecutive patients (16 men and 24 women), with a mean age of 69 years. In all cases, SNRB was successfully performed without complications. The average exposure per hour for each of the four groups was as follows: 0.67 ± 0.56 mSv/s in the direct exposure group, 0.12 ± 0.07 mSv/s in the 0.03-mmPb glove group, 0.019 ± 0.02 mSv/s in the 0.25-mmPb glove group, and 0.001 ± 0.004 mSv/s in the forceps group (p < 0.01). The average annual exposure time limit was 12.4 min in the direct exposure group, 67.9 min in the 0.03-mmPb glove group, 7.5 h in the 0.25-mmPb glove group, and 5.0 days in the forceps group. CONCLUSIONS: Using a radiation reduction glove or forceps greatly decreased the radiation exposure and increased the annual exposure time limit for SNRB.

Fixed Neck Position in Multilevel Cervical Posterior Decompression and Fusion to Reduce Postoperative Disturbances of Cervical Spine Function.

INTRODUCTION: Difficulties with neck mobility often interfere with patients' activities of daily living (ADL) after cervical posterior spine surgery. The range of motion of the cervical spine decreases markedly after multilevel cervical posterior decompression and fusion (PDF). However, details regarding the limitations of cervical spine function due to postoperative reduced neck mobility after multilevel PDF are as yet unclarified. The present study aimed to clarify the quality of life and its related factors after PDF, and the optimal fixed neck position in multilevel PDF that minimizes the limitations of ADL accompanying markedly reduced postoperative neck mobility. METHODS: Limitations of ADL involving neck extension, rotation, and flexion were investigated in 32 consecutive patients who underwent C2-T1 PDF using the responses to the cervical spine function domain of the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). The EuroQol 5 Dimension, Japanese Orthopedic Association score, and five domains of the JOACMEQ were also investigated. We investigated the risk factors regarding the fixed neck position in PDF for the impossibility to perform ADL involving each of three movements using cut-off values obtained from receiver-operating characteristic curves. RESULTS: Postoperative comprehensive quality of life was significantly related to neurological improvements and to poor outcomes of cervical spine function after PDF. The significant risk factors for impossibility to perform ADL involving neck rotation were a C2-C7 lordotic angle ≥ 6° (P = 0.0057) or a proportion coefficient of C2-T1 tilt angle/C2-C7 lordotic angle ≤ 1.8 (P = 0.0024). There were no significant risk factors for impossibility to perform ADL involving neck extension or flexion. CONCLUSIONS: The optimal fixed neck position in C2-T1 PDF to reduce postoperative limitations of ADL involving neck mobility is a C2-C7 lordotic angle of less than 6°, or a C2-T1 tilt angle (°) of greater than 1.8 × the C2-C7 lordotic angle (°).

A novel posterior approach preserving three muscles inserted at C2 in multilevel cervical posterior decompression and fusion using C2 pedicle screws.

PURPOSE: To present a novel posterior approach in multilevel cervical posterior decompression and fusion (PDF) using C2 pedicle screws that preserves the rectus capitis posterior major, oblique capitis inferior, and semispinalis cervicis. METHODS: We analyzed 30 consecutive patients who underwent C2-T1 PDF using an approach that preserved these three muscles without resecting. We assessed O-C2 range of motion (ROM), cross-sectional area of the cervical posterior muscles, rotational ROM, visual analog scale (VAS) for axial pain, neck disability index (NDI), and limitations of activities of daily living (ADL) involving neck movements. RESULTS: Mean preoperative O-C2 ROM (23.6°) was significantly increased postoperatively (33.0°). Mean atrophy rate of the cross-sectional area was 3.9%. Postoperatively, 69.8% of the preoperative rotational ROM (113.3°) was retained. The preoperative VAS for axial pain and the NDI did not increase postoperatively. The postoperative O-C2 ROM (33.9°) in 26 patients for whom extension ADL were possible was significantly larger than that in four patients for whom extension ADL were impossible (26.9°). The postoperative retained rate of rotational ROM (75.8%) in 18 patients for whom rotation ADL were possible was significantly larger than that in 12 patients for whom rotation ADL were impossible (62.3%). CONCLUSIONS: This is potentially an effective approach for maintaining O-C2 ROM and rotational ROM, which enabled good levels of ADL after C2-T1 PDF. Axial pain and NDI were not worse after PDF.

K-line (-) in the Neck-Flexed Position in Patients With Ossification of the Posterior Longitudinal Ligament Is a Risk Factor for Poor Clinical Outcome After Cervical Laminoplasty.

STUDY DESIGN: Retrospective study comparing postoperative clinical outcomes after cervical laminoplasty between K-line (-) ossification of the posterior longitudinal ligament (OPLL) and K-line (+) OPLL in the neck-flexed position. OBJECTIVE: To investigate postoperative outcomes using Japanese Orthopedic Association (JOA) scores, and grip-and-release (GR) and foot-tap (FT) test scores after laminoplasty in patients with K-line (-) OPLL in the neck-flexed position. SUMMARY OF BACKGROUND DATA: Cervical laminoplasty has been reported to lead to poor outcomes in K-line (-) OPLL and good outcomes in K-line (+) OPLL. The cervical spine, however, continues moving in the extension and flexion direction after laminoplasty. METHODS: Patients with cervical myelopathy were divided into K-line (+) and (-) in the neck-flexed position. We compared postoperative outcomes after cervical laminoplasty using recovery rate, as assessed by the JOA score and degree of improvement in the six JOA score items, and performance, as assessed by GR and (FT) tests, between patients with K-line (+) OPLL (n = 18) and K-line (-) OPLL (n = 23) in the neck-flexed position. RESULTS: Recovery rate of JOA score (23.8%) of patients in the K-line (-) group was significantly lower (P = 0.028) than that (46.3%) of K-line (+) group in the neck-flexed position. In the K-line (+) group, significant improvements were seen in all JOA-score items except bladder function; however, in the K-line (-) group, improvements were seen only in upper- and the lower-extremity sensory functions. In the K-line (+) group, mean GR and FT tests significantly improved, but in the K-line (-) group, only mean FT test significantly improved. CONCLUSION: The K-line (-) OPLL in the neck-flexed position is a risk factor for poor clinical outcome after cervical laminoplasty. LEVEL OF EVIDENCE: 4.

Percutaneous ultrasonographic evaluation of the spinal cord after cervical laminoplasty.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To investigate the dynamic changes of cervical spinal cord with postural change after cervical laminoplasty by means of postoperative percutaneous ultrasonography. SUMMARY OF BACKGROUND DATA: Many reports have been published about intraoperative ultrasonographic evaluation of the spinal cord. Few reports have described postoperative diagnostic ultrasonographic findings of the spinal cord after a previous laminectomy. To date, there are no studies that have examined the changes in pulsation pattern and intensity of the spinal cord at different body positions with percutaneous ultrasonography. METHODS: Thirty-three patients after cervical laminoplasty were evaluated postoperatively by percutaneous ultrasonography of the cervical spinal cord. Ultrasonographic images were obtained from 5 different body positions sitting with neck neutral, sitting with neck flexion, sitting with neck extension, prone, and supine position. RESULTS: The pattern and intensity of cervical spinal cord pulsation and the anteroposterior position of the cervical spinal cord changed according to posture. Pulsation of the cervical spinal cord was more common in sitting position, whereas wave motion was more common in supine position.Supine, prone, sitting with neck extension, sitting with neck neutral, and sitting with neck flexion position were ranked in descending order of spinal cord pulsating intensity. Subarachnoidal space ventral to the cervical spinal cord was more likely to appear in the supine position. CONCLUSION: Assuming that good spinal cord pulsation represents good spinal circulation, these results suggest that the supine position will provide the most favorable condition for recovery of the cervical spinal cord.

Limitation of activities of daily living accompanying reduced neck mobility after laminoplasty preserving or reattaching the semispinalis cervicis into axis.

Although difficulties with neck mobility often interfere with patients' activities of daily living (ADL) after cervical laminoplasty, there was no detailed study on the relation between the limitations of ADL accompanying postoperative reduced neck mobility and the cervical posterior approach. The aim of this study was to compare retrospectively the frequency of limitations of ADL accompanying neck mobility after laminoplasty preserving the semispinalis cervicis inserted into the C2 spinous process with that after laminoplasty reattaching the muscle to C2. Forty-nine patients after C4-C7 laminoplasty with C3 laminectomy preserving the semispinalis cervicis inserted into C2 (Group A) and 24 patients after C3-C7 laminoplasty reattaching the muscle (Group B) were evaluated. The frequency of postoperative limitations of ADL accompanying each of three neck movements of extension, flexion and rotation were investigated. The postoperative O-C7 angles at extension and flexion was measured on lateral extension and flexion radiographs of the cervical spine, respectively. The postoperative cervical range of motion in rotation was measured in the cranial view using a digital camera. Frequency of limitations of ADL accompanying extension was lower (P = 0.037) in Group A (2%) than in Group B (17%). Frequency of limitations of ADL accompanying flexion was similar in Group A (8%) and Group B (4%). Frequency of limitations of ADL accompanying rotation was lower (P = 0.031) in Group A (12%) than in Group B (33%). Average O-C7 angle at extension was significantly larger (P = 0.002) in Group A (147 degrees ) than in Group B (136 degrees ). Average O-C7 angle at flexion was similar in Group A (93 degrees ) and Group B (91 degrees ). Average range of motion in rotation was significantly larger (P = 0.004) in Group A (110 degrees ) than in Group B (91 degrees ). This retrospective study suggested that the frequency of limitations of ADL accompanying neck extension or rotation was lower after laminoplasty preserving the semispinalis cervicis inserted into C2 than after laminoplasty reattaching the muscle.

Tonsillar herniation and the cervical spine: a morphometric study of 172 patients.

BACKGROUND: When the neck is flexed in patients with Chiari I malformation, herniated tonsils descend, impacting the spinal canal, and the clivus-canal angle changes and compresses the ventral spinal cord. Therefore, we speculated that the existence of tonsillar herniation might have some influence on the cervical spine, such as changes in range of motion, sagittal alignment, and spondylosis. The purpose of this radiological study was to clarify quantitatively the relation between tonsillar herniation and the cervical spine regarding range of motion, sagittal alignment, and cervical spondylotic change. METHODS: We examined the cervical spine of 609 outpatients with magnetic resonance imaging, and the cerebral tonsils being located below the foramen magnum was defined as tonsillar herniation. Of the 609 patients, 88 (14.4%) had tonsillar herniation. Two of the 88 patients who had complicating osseous anomalies were excluded from this study, and the remaining 86 patients with tonsillar herniation were the subject group (TH group). Of the remaining 521 patients without tonsillar herniation, 86 patients whose age and sex matched those of the TH group were selected at random to be in the control group (Non-TH group). The range of motion, sagittal alignment, and the diameter of the intersegmental dura in the cervical spine in the TH group were compared by age with those in the Non-TH group using a roentgenograph or magnetic resonance imaging. RESULTS: The range of motion at C1-C2 was significantly smaller in the TH group (5.4 degrees ) than in the Non-TH group (8.4 degrees ) in patients over 70 years of age. The level of narrowing of the dura diameter at C5/C6 was significantly higher (P = 0.029) in the TH group (23.3%) than in the Non-TH group (13.4%) in patients over 70 years of age. The cervical alignment was similar in both groups for all age groups. CONCLUSIONS: The existence of tonsillar herniation was associated with loss of range of motion at the upper cervical spine and progression of spondylotic change, especially in elderly patients.

Preliminary Application of One-level Posterior Lumbar Interbody Fusion with Prospace and Facet Fusion Using Local Autograft / 中国修复重建外科杂志

Objective To evaluate the safety and efficacy of one-level posterior lumbar interbody fusion(PLIF) combined with Prospace and facet fusion using local autograft. Methods Clinical and radiographic data of 76 patients treated by this technique was reviewed from May 2002 to December 2004. Of them, there were 52 males and 24 females, with an average age of 53.2 years (23-81 years), including 60 cases of degenerative disc disease, 9 cases of failed back surgery syndrome and 3 cases of spondylolysis. The disese courses were 1.2-8.7 years (mean 3.6 years). The levels of PLIF were: L2,3 in 2 cases, L3,4 in 7, L4,5 in 54, L5/S1 in 10, L4/S1 in 1 and L5,6 in 2. After decompression, Prospace was inserted into interbody space bilaterally,and located in disc space 4 mm beyond the rear edge of the vertebral body. Local laminectomy autograft was packed both laterally into and between 2 implants. Then the remanent local autograft was placed over facet bed. Pedicle screws were used after insertion of Prospace. Clinical results were evaluated by the JOA score. Disc height ratio and lumbar lordosis angles were measured on lateral radiographs. Fusion status was determined by evidence of bridge trabeculae across facet joint and interbody space on CT scan without mobility in lateral dynamic X-rays, and no radiolucent gap between Prospace and endplate. Paired t-test was used for statistical analysis. Results Mean blood loss and operative time was 384 ml and 178 minutes, respectively. The average JOA score at final follow-up (26.1 + 2.7) was significantly improved when compared with that of pre-operation (14.5 ± 4.0, P ＜ 0.05), with a mean recovery rate of JOA score 81.1% (37.5%-100.0%). The fusion rate was 97.4% (74/76). Mean disc height ratio and the involved segmental lordosis angle were increased from preoperative 0.27 ±0.07 and 5.8 + 2.2° to 0.33 + 0.06 and 11.3 + 2.0° respeetively at the final follow-up, and the differences were significant ( P ＜ 0.05). There were no device-related complications. Conclusion This surgical technique combined with Prospace interbody device is a safe and effective surgical option for patients with one-level lumbar disorders when PLIF is warranted.

Axial symptoms after cervical laminoplasty with C3 laminectomy compared with conventional C3-C7 laminoplasty: a modified laminoplasty preserving the semispinalis cervicis inserted into axis.

STUDY DESIGN: Results of C4-C7 laminoplasty with C3 laminectomy and C3-C7 laminoplasty were compared. OBJECTIVES: To clarify prospectively whether the modified laminoplasty preserving the semispinalis cervicis inserted into C2 could reduce the axial symptoms compared with conventional laminoplasty reattaching the muscle to C2. SUMMARY OF BACKGROUND DATA: Intraoperative damage of the semispinalis cervicis is relevant to the development of axial symptoms after laminoplasty. In C3-C7 laminoplasty, however, it is difficult to preserve the muscle insertion into C2 while opening the C3 lamina. METHODS: The axial symptoms of 40 patients (Group A) with C4-C7 laminoplasty with C3 laminectomy were compared with those of 16 patients (Group B) with C3-C7 laminoplasty. The cross-sectional areas of the cervical posterior muscles were measured on magnetic resonance images. RESULTS: The number of patients with no postoperative axial symptoms increased (P = 0.035) from 19% to 52.5%, and the number of patients whose symptoms worsened after surgery decreased (P = 0.020) from 50% to 17.5%. The average atrophy rate of cross-sectional area was smaller (P < 0.001) in Group A (2.4%) than in Group B (10.8%). CONCLUSIONS: This method was less invasive to the cervical posterior muscles than C3-C7 laminoplasty. This is an effective procedure for preventing postoperative axial symptoms.

Interaction between proteoglycans and alpha-elastin in construction of extracellular matrix of human yellow ligament.

One type of large proteoglycan and three types of small proteoglycans (decorin, decorin-subtype, and biglycan) were purified by chromatography, and alpha-elastin was isolated by alkali treatment from human yellow ligaments taken at the time of operation. The interaction of the proteoglycans with immobilized alpha-elastin on a sensor was analyzed by surface plasmon resonance, and we confirmed that each of the small proteoglycans exhibited a specific binding to alpha-elastin. The binding sites of small proteoglycans were contained in the protein cores. In addition, the differences in the interaction of the small proteoglycans with alpha-elastin of normal and ossified ligaments were compared. The interactions of the small proteoglycans with alpha-elastin of the ossified ligaments were lower than those with alpha-elastin of the normal ligaments. In the ossified ligaments, neodesmosine, one of the cross-linking amino acids, was significantly less than in the normal ligaments (p < .05).

Anatomic study of the semispinalis cervicis for reattachment during laminoplasty.

Some patients who had cervical laminoplasty with subsequent substantial loss of cervical lordosis have shown failed healing of a repaired semispinalis cervicis. We also have identified some patients in whom it is difficult to repair the C2 spinous process during laminoplasty. We therefore quantitatively analyzed the morphologic features of the C2 insertion of the semispinalis cervicis and obtained data relevant to the repair of the muscle. In 24 cadavers, the width and height of the semispinalis cervicis insertion in C2 and the length and opening angle of the C2 spinous process were measured. We observed considerable individual variations in the morphologic features of the C2 spinous process and the C2 insertion of the semispinalis cervicis. The opening angle of the C2 spinous process was smaller in males than in females. In most of the cases, the width of the insertion was narrower than the width of the spinous process spacers that commonly are used in laminoplasty. Preoperative prediction of the morphologic features of insertion at the original site is possible by measuring the opening angle of the C2 spinous process using three-dimensional computed tomography because the muscle insertion correlated with the angle of the C2 spinous process. This information may be useful in reattaching the semispinalis cervicis during cervical laminoplasty.

Domain structure of chondroitin sulfate E octasaccharides binding to type V collagen.

We demonstrated previously that chondroitin sulfate E (ChS-E) binds to type V collagen (Munakata, H., Takagaki, K., Majima, M., and Endo, M. (1999) Glycobiology 9, 1023--1027). In this study, we investigated the structure and binding of ChS-E oligosaccharides. Eleven oligosaccharides were isolated from ChS-E by gel filtration chromatography and anion-exchange high performance liquid chromatography after hydrolysis with testicular hyaluronidase. Separately, seven oligosaccharides were custom synthesized using the transglycosylation reaction of testicular hyaluronidase. Structural analysis was performed by enzymatic digestions in conjunction with high performance liquid chromatography and mass spectrometry. This library of 18 oligosaccharides was used as a source of model molecules to clarify the structural requirements for binding to type V collagen. Binding was analyzed by a biosensor based on surface plasmon resonance. The results indicated that to bind to type V collagen the oligosaccharides must have the following carbohydrate structures: 1) octasaccharide or larger in size; 2) a continuous sequence of three GlcAbeta1--3GalNAc(4S,6S) units; 3) a GlcAbeta1--3GalNAc(4S,6S) unit, GlcAbeta1--3GalNAc(4S) unit or GlcAbeta1--3GalNAc(6S) unit at the reducing terminal; 4) a GlcAbeta1--3GalNAc(4S,6S) unit at the nonreducing terminal. It is likely that these characteristic oligosaccharide sequences play key roles in cell adhesion and extracellular matrix assembly.