Open-door Laminoplasty For Cervical Myelopathy Research Articles

Exoscopic Minimally Invasive Open-Door Laminoplasty for Cervical Myelopathy: A Technical Note and Preliminary Analysis of Clinical Outcomes during the Acute Postoperative Period.

Background/Objectives: Expansive open-door laminoplasty results in favorable clinical outcomes for cervical myelopathy. However, some postoperative complications associated with surgical invasiveness, such as axial neck pain and kyphosis, have not been resolved. The use of an exoscope, which is a recently introduced novel magnification tool, allows for traditional open-door laminoplasty with minimal invasiveness. Therefore, we propose the use of exoscopic minimally invasive open-door laminoplasty (exLAP) and present its clinical outcomes during the acute postoperative period. Methods: A total of 28 patients who underwent open-door laminoplasty at C3-C6 were reviewed. Of these patients, 17 underwent exLAP (group M) and 11 underwent conventional Hirabayashi open-door laminoplasty (group H). Outcomes were evaluated using numerical rating scale (NRS) scores for neck pain and the frequency of oral analgesic use from postoperative day 1 to 7. Results: The NRS score for neck pain was significantly lower for patients in group M than for those in group H. Conclusions: ExLAP is a novel, practical, and minimally invasive surgical technique that may alleviate the postoperative axial pain of patients with cervical myelopathy.

Open-door laminoplasty with stand-alone autologous bone spacers: evaluation of enlarged laminar arch with CT-multiplanar reconstruction.

The authors aimed to determine the efficacy of open-door laminoplasty with stand-alone autologous bone spacer for preserving enlarged lamina in patients with cervical myelopathy. Patients who underwent open-door laminoplasty for cervical myelopathy with stand-alone autologous bone spacer and underwent CT 1 week and 1 year after surgery were included in this study. There were 20 men and 13 women, with an average (range) age of 65.0 (37-86) years. Seventeen patients were younger than 70 years, and 16 patients were older than 70 years. Autogenous bone spacers made from spinous processes were used in all patients. Slits were made on both sides of the spacers. The lamina was raised with a curette, and a spacer was inserted without any sutures. Before surgery and 1 week and 1 year after surgery, the anteroposterior diameter (APD) of the spinal canal was measured using midsagittal-plane CT-multiplanar reconstruction. The bone union rate of the hinge side and autogenous bone spacer of each lamina was determined using CT images obtained 1 year after surgery. Results 1 year after surgery were evaluated using Japanese Orthopaedic Association (JOA) score. The mean ± SD APD increase rate was 56.3% ± 21.3% 1 week after surgery and 51.7% ± 20.6% 1 year later. The average APD decrease rate was 2.9% ± 3.8%. The bone union rate on the hinge side was 100%, and that of autologous bone spacer was 93.8% 1 year after surgery. The mean APD decrease rate was 3.3% in patients younger than 70 years and 2.3% in those older than 70 years. There was no significant difference between the two groups (p > 0.05, nonpaired t-test). The JOA score averaged 10.1 before surgery and 13.3 a year after surgery (total score 17). The average improvement rate was 46.3% ± 26.4%. The authors devised and implemented a technique for inserting an autologous bone spacer between the opened lamina and lateral mass without sutures. The enlarged spinal canal was maintained 1 year after surgery. This simple method does not require any instrumentation or additional cost to stabilize the opened lamina.

The Efficacy of Ultrasonic Bone Scalpel for Unilateral Cervical Open-Door Laminoplasty: A Randomized Controlled Trial.

In cervical open-door laminoplasty for cervical myelopathy, a high-speed rotatory drill and rongeurs are used to make unicortical troughs and bicortical openings in the laminae. The lamina is reflected at the trough to enlarge the spinal canal, followed by bone healing on the hinge side to stabilize laminoplasty. The ultrasonic bone scalpel (UBS) has been used due to theoretical advantages including a better hinge union rate, less soft tissue trauma, less neurological injury, and shorter operative time. To assess the superiority of UBS for hinge union compared to the drill through randomized controlled trial. In 190 randomly allocated cervical myelopathy patients, the trough and opening at the lamina were made using either the drill (n=95) or UBS (n=95) during 2015 to 2018. The primary outcome was the hinge union rate on 6-mo postoperative computed tomography. Secondary outcomes included the hinge union rate at 12 mo, the operative time, intraoperative/postoperative bleeding, neurological injury, complications, and clinical outcomes over a 24-mo follow-up. Hinge union in all laminae was achieved in 60.0% (drill) and 43.9% (UBS) of patients at 6 mo (intention-to-treat analysis; P=.02; odds ratio, 2.1) and in 91.9% (drill) and 86.5% (UBS) at 12 mo. Dural injury only occurred in the drill group (2.1%), and the UBS group showed significantly less intraoperative bleeding (P<.01). The other secondary outcomes did not differ between groups. The hinge union rate was inferior in the UBS group at 6 mo postoperatively, but UBS was efficacious in reducing dural injuries and bleeding.

The Use of Preoperative and Intraoperative Pavlov Ratio to Predict the Risk of Postoperative C5 Palsy after Expansive Open-Door Laminoplasty for Cervical Myelopathy.

Background:No standard preoperative preventive measure has been established to decrease the occurrence of C5 palsy after expansive open-door laminoplasty. The aim of this study is to establish a reliable measured parameter in predicting the risk of the postoperative C5 palsy.Materials and Methods:A total of 276 patients receiving posterior open-door laminoplasty for cervical spinal stenotic myelopathy were studied. The patients were divided into two groups according to the preoperative Pavlov ratio (Group A: Pavlov ratio <0.65 and Group B: Pavlov ratio ≥0.65). Correlations between the occurrence of postoperative C5 palsy and Pavlov ratio were analyzed, and Group A was further tested. The surgical procedures, clinical symptoms, and Pavlov ratio were described.Results:The patients with Pavlov ratio <0.65 had a higher risk of developing postoperative C5 palsy (P < 0.05, odds ratio [OR] = 2.91). No significant difference was found in gender, age, etiology, type of operation, and pre- and postoperative Japanese Orthopaedic Association scores between patients with and without postoperative C5 palsy. The cutoff (1.01) of receiver operating characteristic curve of the postoperative Pavlov ratio of the Group A was calculated. The postoperative Pavlov ratio ≥1.01 of the patients in Group A was a significant risk factor of the development of postoperative C5 palsy (P < 0.01, OR = 10.83).Conclusions:The preoperative Pavlov ratio <0.65 at the C5 level was more likely to develop the postoperative C5 palsy. When the preoperative Pavlov ratio is <0.65, the postoperative Pavlov ratio ≥1.01 at the C5 level is a reliable predictor for the development of postoperative C5 palsy. Pavlov ratio may be one of the reasons for postoperative C5 palsy.

Impact of Cervical Sagittal Alignment on Axial Neck Pain and Health-related Quality of Life After Cervical Laminoplasty in Patients With Cervical Spondylotic Myelopathy or Ossification of the Posterior Longitudinal Ligament

This is prospective observational study. To prospectively investigate the correlation among axial neck pain; a newly developed patient-based quality of life outcome measure, the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ); and cervical sagittal alignment after open-door laminoplasty for cervical myelopathy. Many studies have focused on postoperative axial neck pain after laminoplasty. However, the correlation among cervical sagittal alignment, neck pain, and JOACMEQ has not been investigated. In total, 57 consecutive patients treated by open-door laminoplasty for cervical myelopathy were included (mean age, 63.7 y; 15 women and 42 men) and divided into 2 groups according to diagnosis [cervical spondylotic myelopathy (CSM) group: 35 patients, and ossification of the posterior longitudinal ligament (OPLL) group: 22 patients]. JOA score, a subdomain of cervical spine function (CSF) in the JOACMEQ, and the visual analog scale for axial neck pain were assessed preoperatively and 12 months postoperatively. Radiographic cervical sagittal parameters were measured by C2 sagittal vertical axis (C2 SVA), C2-C7 lordosis, C7 sagittal slope (C7 slope), and range of motion. C2 SVA values in both groups shifted slightly anteriorly between preoperative and 12-month postoperative measurements (CSM: +19.7±10.9 mm; OPLL: +22.1±13.4 mm vs. CSM: +23.2±16.1 mm; OPLL: +28.7±15.4 mm, respectively). Postoperative axial neck pain in the OPLL group showed strong negative correlations with C2 SVA and C7 slope. Strong negative correlations were found between axial neck pain and CSF in both the preoperative CSM and OPLL groups (CSM: r=-0.45, P=0.01; OPLL: r=-0.61, P<0.01) and between axial neck pain and CSF in the postoperative OPLL group (r=-0.51, P=0.05). This study demonstrated a significant negative correlation between neck pain and CSF in both the CSM and OPLL groups preoperatively and in the OPLL group postoperatively. Radiographic cervical sagittal alignment did not significantly correlate with preoperative or postoperative axial neck pain.

Posterior cervical laminoplasty in the North American Population: A minimum of two year follow-up

BackgroundThe efficacy of expansile cervical laminoplasty for cervical spondylotic myelopathy has been validated in the literature. To date, however, the majority of large, long-term data in the literature have originated in Japan. Few studies have originated from North America that include follow up greater than one year, and none of these includes a single surgeon's experience. This paper presents the retrospective results of a single surgeon with an average follow up of 47 months in a large population of North American patients. MethodsA single surgeon's series of 80 consecutive patients who underwent expansile open-door laminoplasty for cervical myelopathy was reviewed. The severity of disability was graded using the Nurick Functional Disability Score and the Miami Upper Extremity Function (MUEF) score. Patients were evaluated preoperatively, six months postoperatively, and at a minimum of 24 months postoperatively. All examinations were performed by a single physician. MRI scans of the cervical spine were obtained at four months postoperatively in all patients. Radiographs were used to evaluate postoperative lordosis. ResultsAverage length of follow up was 47 months. Nurick scores improved from an average of 2.3 preoperatively to postoperative scores of 1.5 (p>.05) at six months and 1.4 (p>.05) at two years. MUEF scores also improved at both the six month and two year intervals. All patients had improved canal diameter on post-operative MRI scan evaluation obtained four months post-operatively. ConclusionThis study confirms that laminoplasty is a safe and effective treatment of cervical spondylotic myelopathy in the North American population. Level of evidenceCase Series Level IV.

Delayed hinge fracture after plate-augmented, cervical open-door laminoplasty and its clinical significance

Background contextAmong the various forms of laminoplasty fixation, plate augmentation provides a semirigid arch reconstruction and is gaining popularity as the result of its safety and effectiveness. However, the effects of this procedure on hinge status and subsequent bony healing remain unclear. PurposeWe sought to evaluate the status and time course of bony healing of the hinge gutter and to determine the effect on postoperative clinical course of plate-only, open-door cervical laminoplasty. Study designThis was a retrospective clinical series. Patient sampleA total of 79 adult men and women undergoing cervical laminoplasty in a university hospital setting were studied. Outcome measuresTime-dependent changes in hinges observed on computed tomography (CT) were used to measure the radiological outcome. A numerical rating scale of axial neck pain and arm pain was used to evaluate the clinical outcome. MethodsPatients who underwent plate-only, open-door laminoplasty for cervical myelopathy and had available postoperative CT scans were enrolled in this study. Neck pain intensity before and 1 year after surgery was assessed with questionnaires. CT scans (n=125) obtained after surgery were assessed in terms of bony healing of the hinge. ResultsMost of the hinges were initially well-bent. Only 9% were found to be “fractured” or “in danger of fracture” at 1 week. Primary healing without callus formation, which is the next step of bony healing of well-bent hinges, was observed in 62% of cases at month 4. The remaining 38% were classified as “fractured” or in the process of “secondary healing.” A similar number of hinges was classified as “secondarily healed” after 1 or 2 years of follow-up. All except one hinge were well united and incorporated at the final follow-up, and the number of hinges classified as “fractured or secondarily healed” related to postoperative axial neck pain with respect to the 1-year visual analog scale for the neck and the Neck Disability Index. ConclusionsAlthough plate-only, open-door laminoplasty is a safe and reliable surgery for decompression of multilevel cervical disease, the fixation that it provides on the open side may not be sufficiently stable to allow successful primary healing. Additional attention should be paid to the hinged side to prevent delayed fracture in the early postoperative period and to reduce postoperative axial pain.

Risk factors associated with upper extremity palsy after expansive open-door laminoplasty for cervical myelopathy

Background contextPostoperative paresis, so-called C5 palsy, of the upper extremities is a common complication of cervical surgery. There have been several reports about upper extremity palsy after cervical laminoplasty for patients with cervical myelopathy. However, the possible risk factors remain unclear. PurposeTo investigate the factors associated with the development of upper extremity palsy after expansive open-door laminoplasty for cervical myelopathy. Study designA retrospective review of medical records. Patient sampleA total of 102 patients (76 men and 26 women) were eligible for analysis in this study. The mean age of the patients was 58.7 years (range 35–81 years). Sixteen patients (13 men and 3 women, average age 62.8 years) with palsy were categorized as Group P, and eighty-six patients (63 men and 23 women, average age 57.8 years) without palsy as Group C. Outcome measuresThe demographic data collected from both groups were age, sex, duration of symptoms, disease, and type of surgical procedure. Cervical curvature index, width of the intervertebral foramen (WIF) at C5, anterior protrusion of the superior articular process (APSAP), number of compressed segments, high–signal intensity zone at the level corresponding to C3–C5 (HIZ:C3–C5), and posterior shift of the spinal cord (PSSC) were also evaluated. MethodsUpper extremity palsy was defined as weakness of Grade 4 or less of the key muscles in the upper extremity by manual muscle test without any deterioration of myelopathic symptoms after surgery. Comparisons were made with screen for the parameters with significant differences, and then we further analyzed these parameters by logistic regression analysis (the forward method) to verify the risk factors of the upper extremity palsy. ResultsSignificant differences in diagnosis, the type of procedure, WIF, APSAP, and HIZ:C3–C5 were observed between the two groups. No statistical difference in PSSC between the groups was noted (2.06 vs. 2.53 mm, p=.247). In logistic regression analysis, ossification of the posterior longitudinal ligament (OPLL), cervical open-door laminoplasty together with posterior instrumented fusion (CLP+PIF), and WIF were found to be significant risk factors for postoperative upper extremity palsy. ConclusionsPatients with preoperative foraminal stenosis, OPLL, and additional iatrogenic foraminal stenosis because of CLP+PIF were more likely to develop postoperative upper extremity palsy. Attention should be given to the WIF determined on preoperative computed tomography of the C5 root. To prevent iatrogenic foraminal stenosis, appropriate distraction between spine segments should be provided during placement of the rod.

Analysis of C5 Palsy After Cervical Open-door Laminoplasty

A retrospective study. To determine the clinical and imaging characteristics of postoperative C5 palsy after cervical open-door laminoplasty. Postoperative C5 palsy is a common complication of cervical laminoplasty, and although there are several hypotheses regarding its etiology, the pathogenesis and preventive measures remain unidentified and many controversies remain. A total of 141 consecutive patients (100 men and 41 women) who had undergone open-door laminoplasty for cervical myelopathy between 2006 and 2009 were included in this study. Postoperative C5 palsy was defined as deltoid muscle weakness of a grade <3 in manual muscle test. The patients were divided into 2 groups: 1 that had experienced C5 palsy (PG; the palsy group) and the other that had not (NPG; the nonpalsy group). The parameters evaluated were the incidence of C5 palsy, the level at which spinal cord compression appeared preoperatively, the spinal cord level showing a T2 high-signal intensity lesion on magnetic resonance imaging, T2 high-signal intensity lesions newly appearing postoperatively, and the diameters of the C4/5 and C5/6 foramens. The incidence of C5 palsy was 6.4% (9/141 cases). There were no significant differences between the 2 groups in sex, age, diagnosis, operation time, blood loss, level of spinal cord compression, level of T2 high-signal lesion, or new T2 high-signal lesions. The average diameter of the C4/5 foramen was 1.99 mm in the PG and 2.76 mm in the NPG (P<0.005). In contrast, the average diameter of the C5/6 foramen was 2.35 mm in PG and 2.50 mm in the NPG. There was a significant difference in the diameter of the C4/5 foramen between the PG and the NPG. The results suggest that the main etiology of C5 palsy is impairment of the C5 nerve root induced by preexisting C4/5 foraminal stenosis.

Can Prophylactic Bilateral C4/C5 Foraminotomy Prevent Postoperative C5 Palsy After Open-Door Laminoplasty?

A prospective study. To evaluate the effectiveness of prophylactic C4/C5 microforaminotomy with open-door laminoplasty for cervical myelopathy in preventing postoperative C5 palsy. Postoperative C5 palsy is a common complication of cervical laminoplasty. Although the etiology of C5 palsy and preventive measures remain unclear, we hypothesize that C5 palsy is caused by C5 nerve root impairment induced by potential C4/C5 foraminal stenosis and posterior shifting of the spinal cord after laminoplasty. The study included 141 consecutive patients with cervical myelopathy (103 men and 38 women) who underwent open-door laminoplasty with prophylactic bilateral C4/C5 foraminotomy between 2009 and 2010. These were designated as the foraminotomy group (FG). One hundred forty-one consecutive patients (100 men and 41 women) who underwent open-door laminoplasty without prophylactic foraminotomy during 2006 to 2008 served as a control group. This was the nonforaminotomy group (NFG). The incidence of C5 palsy, operation time, blood loss, and the number of decompressed disc levels were recorded. The incidence of C5 palsy was 1.4% (2 of 141 cases) in the FG, and 6.4% (9 of 141 cases) in the NFG. The mean operation times were 129 and 102 minutes, respectively. There were significant differences in the incidence of C5 palsy and operation time (both comparisons, P < 0.05). There were no significant differences in blood loss or the number of decompressed disc levels (both comparisons, P > 0.05). Prophylactic bilateral C4/C5 microforaminotomy significantly decreased the incidence of postoperative C5 palsy. These results suggest that the main etiology of C5 palsy was C5 root impairment. However, 2 patients experienced C5 palsy despite undergoing prophylactic foraminotomy, which indicated that other factors including spinal cord impairment after acute decompression against cervical canal stenosis may also be considered as minor etiologies of C5 palsy. We conclude that prophylactic C4/C5 foraminotomy was an effective preventive measure against postoperative C5 palsy after laminoplasty.

Clinical Application of a New Plate Fixation System in Open-door Laminoplasty

The purpose of this retrospective clinical series was to evaluate the benefits and complications of plate fixation for open-door laminoplasty in cervical spondylotic myelopathy with multilevel spinal stenosis compared with open-door laminoplasty without fixation. Forty-nine patients underwent open-door laminoplasty for cervical myelopathy with multilevel spinal stenosis with at least 13 months of follow-up. A plate was used as the sole method of fixation between the lateral mass and lamina with 3 screws. Computed tomography scans obtained pre- and postoperatively were assessed for plate complications and spinal canal enlargement. Pre- and postoperative neurological condition was assessed by the Japanese Orthopedic Association (JOA) myelopathy score. Overall cervical spine range of motion (ROM) was measured in full flexion and extension radiographs pre- and postoperatively. No restenosis due to door reclosure was noted, and no plates failed. No screws were backed out or broken. Almost all patients showed neurological improvement. The JOA score increased by 3.9±0.7 points in the suture group and 4.3±0.8 points in the plate group (P>.05). The postoperative increase in mean anteroposterior diameter of the spinal canal from C3 to C7 was 4.5±0.6 mm in the suture group and 5.1±0.5 mm in the plate group. The greater mean anteroposterior diameter increase in the plate group was statistically significant (P<.01). The mean cervical ROM decreased in the plate and suture groups postoperatively (P<.001). No significant difference was found in mean cervical ROM reduction between the groups (P>.05). No difference in axial symptoms was found between the 2 groups.

Efficacy of Modified Expansive Open-Door Laminoplasty for Cervical Myelopathy

Objectives: Expansive open-door laminoplasty is used widely for the treatment of cervical spondylosis and Ossification of the Posterior Longitudinal Ligament (OPLL). We have developed a unique modification of the surgical procedure to keep the lamina expanded, with the aim of preventing reclosure of the vertebral arch. To examine the effectiveness of and problems associated with the modified expansive open-door laminoplasty technique developed at our institution by evaluating the surgical outcomes. Methods and Materials: Fifty-six patients (46 men and 10 women) underwent the modified expansive open-door laminoplasty and were followed up for at least 1 year. Thirty-eight had Cervical Spondylotic Myelopathy (CSM) and 18 had OPLL. The patients were 34 to 89 years of age (mean: 60.9 years). The severity of myelopathy was evaluated according to the Japanese Orthopaedic Association’s scoring system. Surgical outcomes were evaluated using Hirabayashi’s system for determining recovery rate. In the radiographic analysis, the following angles were measured before and after surgery: lordosis angle and Range of Motion (ROM) at C2 - C7 on lateral radiographs, and opening angle on computerized tomography (CT). The presence and absence of axial pain and postoperative C5 palsy were also evaluated. Results: The rate of JOA score improvement was about 60%, the lordosis angle observed on lateral radiographs was maintained. ROM decreased after surgery in both the CSM and OPLL groups, and the extent of the decrease was similar to that in previous reports. The opening angle of the lamina was 62°- 65° on post-operative CT. Axial pain was reported by 34% of patients. Conclusions: Our modified procedure produced satisfactory postoperative outcomes based on the clinical data and imaging findings for both CSM and OPLL. The advantage of this procedure is that it avoids potential complications associated with bone grafts or implants.

Features of Axial Neck Pain after Open-Door Laminoplasty for Cervical Myelopathy

Features of Axial Neck Pain after Open-Door Laminoplasty for Cervical Myelopathy

Long-term Results of Expansive Open-Door Laminoplasty for Cervical Myelopathy−Average 14-Year Follow-up Study

Retrospective case series on long-term follow-up results of original expansive open-door laminoplasty for cervical myelopathy due to cervical spondylosis (CSM) and ossification of posterior longitudinal ligament (OPLL). To elucidate efficacy and problems of original open-door laminoplasty to improve future surgical outcomes. Little information is available on long-term outcomes of original open-door laminoplasty without grafts, implants, or instruments. The study group included 80 patients who underwent original open-door laminoplasty and were followed for minimum 10 years. Clinical results, including Japanese Orthopedic Association scores, recovery rates, occurrences of complications, and long-term deterioration were investigated. Cervical alignments, type of OPLL, cervical range of motion, anteroposterior diameter of spinal canal, and progression of OPLL were assessed on plain radiographs. Spinal cord decompression was verified on magnetic resonance imaging. Average Japanese Orthopedic Association score and recovery rate improved significantly until 3 years after surgery and remained at an acceptable level in both cervical spondylosis and OPLL patients with slight deterioration after 5 years. Segmental motor palsy developed in 8 patients. Late deterioration, mainly lower extremity motor score decline, developed in 8 CSM and 16 OPLL patients. Overall cervical range of motion decreased by 36%. Patients with cervical lordosis decreased gradually in both patient groups. Such changes in alignments did not affect surgical results in CSM patients, while OPLL patients with preoperative kyphosis had lower recovery rates than those with straight and lordotic alignments. OPLL progression that was detected in 66% of patients did not affect clinical results. Although infrequent, magnetic resonance imaging revealed atrophy of spinal cord, spinal cord compression at adjacent segments due to degenerative changes and OPLL progression. Long-term results of open-door laminoplasty without bone graft, graft substitutes, or instruments were satisfactory. However, segmental motor paralysis, kyphosis, established before and after surgery, OPLL progression, and late deterioration due to age-related degeneration remain challenging problems.

Open-Door Laminoplasty for Cervical Myelopathy Resulting From Adjacent-Segment Disease in Patients With Previous Anterior Cervical Decompression and Fusion

This is a retrospective study of patients with cervical myelopathy resulting from adjacent-segment disease who were treated by open-door expansive laminoplasty. The purpose of this study was to evaluate the effectiveness of laminoplasty for cervical myelopathy resulting from adjacent-segment disease. Adjacent-segment disease is one of the problems associated with anterior cervical decompression and fusion. However, the optimal surgical management strategy is still controversial. Thirty-one patients who underwent open-door expansive laminoplasty for cervical myelopathy resulting from adjacent-segment disease and age- and sex-matched 31 patients with myelopathy who underwent laminoplasty as the initial surgery were enrolled in the study. The pre- and postoperative Japanese Orthopedic Association scores (JOA scores) and the recovery rate were compared between the two groups. The average JOA scores in the patients with adjacent-segment disease and the controls were 9.2 +/- 2.6 and 9.4 +/- 2.3 before the expansive laminoplasty and 11.9 +/- 2.8 and 13.3 +/- 1.7 at the follow-up examination, respectively; the average recovery rates in the two groups were 37.1 +/- 22.4% and 50.0 +/- 21.3%, respectively (P = 0.04). The mean number of segments covered by the high-intensity lesions on the T2-weighted magnetic resonance images was 1.87 and 0.9, respectively (P = 0.001). Moderate neurologic recovery was obtained after open-door laminoplasty in patients with cervical myelopathy resulting from adjacent-segment disc disease, although the results were not as satisfactory as those in the control group. This may be attributed to the irreversible damage of the spinal cord caused by persistent compression at the adjacent segments.

P53. Surgical outcomes of open-door laminoplasty for cervical myelopathy due to adjacent segment disease in patients with previous anterior cervical decompression and fusion

BACKGROUND CONTEXT: Adjacent segment disease is one of the problems associated with anterior cervical decompression and fusion. The choice of an optimal surgical management for cervical myelopathy due to adjacent segment disease is still controversial.

Lordotic alignment of the spine and spinal cord following en bloc open-door laminoplasty for cervical myelopathy

Lordotic alignment of the spine and spinal cord following en bloc open-door laminoplasty for cervical myelopathy

Multiple regression analysis of the factors influencing the results of expansive open-door laminoplasty for cervical myelopathy due to ossification of the posterior longitudinal ligament.

We conducted a multiple regression analysis on the surgical results (minimum follow-up of 5 years) of 55 patients who underwent expansive open-door laminoplasty (open-door ELAP) for cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL) in order to determine statistically the impact of factors influencing the results. Duration of myelopathy was found to be a significant factor indicating poor results, while progression of ossification and age at the time of surgery were significant factors indicating deterioration. Three other factors (preoperative severity of myelopathy, degree of spinal canal expansion and changes of the curve indices before and after surgery) did not have a significant influence on the results. To improve the surgical results, it is thus essential to operate on patients as soon as they develop symptoms of myelopathy. There exists a certain limitation in posterior decompression for OPLL including open-door ELAP until prevention of the progression of ossification becomes possible.

Lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy: a magnetic resonance imaging study.

We investigated lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy. Fifty-five patients (32 men and 23 women) were studied, with an average follow-up of 2.4 years. Radiological examination included evaluation of lordosis of the cervical spine and spinal cord, degree of enlargement of bony spinal canal, and the magnitude of posterior cord migration. We also correlated these changes with neurological improvement. Postoperatively, there was an average of 5% loss of cervical spine lordosis (P > 0.01) on radiographs and 12% reduction in the lordotic alignment of the spinal cord (P > 0.05) on magnetic resonance imaging. Postoperatively, the size of the bony spinal canal increased by 48%. Posterior cord migration showed a significant correlation with the preoperative cervical spine and spinal cord lordosis (P < 0.05). Thirty-seven (67%) patients with neurological improvement exceeding 50% showed significant posterior cord migration following laminoplasty compared with those demonstrating less than 50% improvement (P = 0.01). Our results suggest that a significant neurological improvement is associated with posterior cord migration after cervical laminoplasty.