Comparison of laminoplasty versus laminectomy and fusion in the treatment of multilevel cervical ossification of the posterior longitudinal ligament: A systematic review and meta-analysis

BACKGROUND

Laminoplasty (LP) and laminectomy with fusion (LF) were recognized as two reliable and effective way in treating multilevel cervical ossification of the posterior longitudinal ligament (OPLL). However, there was no clear conclusion on which method is better. A meta-analysis was conducted to evaluate the clinical results between LP and LF in the treatment of multilevel cervical OPLL.

METHODS

An extensive search of literature was performed in PubMed, Embase, the Cochrane library, CNKI (Chinese database), and WANFANG (Chinese database). The following outcomes were extracted: the Japanese Orthopedic Association (JOA) scores, visual analog scale (VAS), cervical lordosis, cervical range of motion (ROM), complications, blood loss, and operation time. Data analysis was conducted with RevMan 5.3.

RESULTS

A total of 11 studies were included in the final analysis. The results indicated that no significant differences between LP and LF group in terms of preoperative JOA scores (P = .58), postoperative JOA scores (P = .60), JOA scores improvement rate (P = 0.64), preoperative VAS (P = .34), postoperative VAS (P=.20), preoperative range of motion (ROM) (P = .10), postoperative ROM (P = .18), preoperative cervical lordosis (P = .56), C5 palsy (P = .16), and axial pain (P = .21). LF group showed larger postoperative cervical lordosis than LP group [standardized mean difference (SMD) = 1.13 (2.03, 0.24), P = .01]. However, LP group showed lower operation time [mean difference (MD) = 19.42 (26.87, 11.97), P < .001] and blood loss [MD = 94.78 (179.05, 10.51), P = .03] than LF group.

CONCLUSION

Both LP and LF can achieve clinical improvement in the treatment of multilevel cervical OPLL. LF was superior to LP in maintaining cervical lordosis. However, LP showed lower surgical trauma than LF. Kyphosis line (K-line) may be a good criterion in the selection of posterior surgery. LP was performed for the patients with K-line (+) and LF for K-line (-).

Factors associated with surgical outcomes of cervical ossification of the posterior longitudinal ligament

To investigate factors associated with surgical outcomes of cervical ossification of the posterior longitudinal ligament (OPLL). This retrospective study included patients (662 males and 251 females; mean age 55.8 years) with symptomatic OPLL. All patients had been diagnosed with OPLL based on cervical magnetic resonance imaging and computed tomography scans. Demographic, surgical outcome was measured using visual analog scale (VAS) and Japanese Orthopedic Association (JOA) scale scores. The results of our study indicated radicular pain was more common in segmental and circumscribe OPLL subtypes (P < 0.05). An anterior approach was favored in patients with less than 3 involved vertebral levels (P < 0.05). All surgical methods showed good outcomes (P < 0.05). Continuous and mixed OPLL subtypes showed worse surgical outcome with higher VAS and JOA scores (P < 0.05). Laminoplasty and anterior cervical discectomy and fusion were significantly associated with a higher recovery rate (P < 0.05). Among these patients, there were more complications with the anterior approach (P < 0.05). Male gender, open door laminoplasty ipsilateral, and ipsilateral-to-symptom-side opening were associated with postoperative C5 palsy (P < 0.05). Cervical OPLL may cause myelopathy, surgery is a safe and effective treatment for OPLL. There were no differences in clinical outcome according to surgical type, but complication rates varied depending on sex and surgical approach to symptom.

Assessment of Myelopathy in Cervical Ossification of the Posterior Longitudinal Ligament by Magnetic Resonance Imaging-Assisted 3-Dimensional Measurement

BACKGROUND

Ossification of the posterior longitudinal ligament (OPLL) is a 3-dimensional (3D) disease that causes cervical myelopathy. The conventional 2-dimensional (2D) measurement of OPLL has limitations in estimating cord compression and myelopathy. In this study, we attempted to use 3D computed tomography (CT) and magnetic resonance imaging (MRI) to measure the 3D occupying ratio of OPLL and investigate its significance in the assessment of spinal cord myelopathy.

METHODS

Three-dimensional CT and MRI were performed in 50 patients with cervical OPLL at a neutral position before surgery. MRI was done to determine the extent of spinal cord compression. The CT data were saved in DICOM format and analyzed using Mimics 17.0. Then a 3D model of OPLL was semiautomatically segmented at a specific threshold. The following data were measured: diameter of the spinal canal, thickness of the OPLL, and 3D volume of the OPLL and spinal canal. The Japanese Orthopedic Association (JOA) score was used to assess the cervical spinal cord function.

RESULTS

Pearson correlation analysis showed that both the occupying ratio and the 3D occupying ratio were significantly and negatively correlated with the JOA score. Multiple linear regression analysis indicated that only the 3D occupying ratio showed a significantly negative correlation with the JOA score, whereas age, sex, and the occupying ratio were insignificantly associated with the JOA score.

CONCLUSIONS

The 3D occupying ratio of OPLL is a reliable indicator for assessing the severity of spinal cord myelopathy. MRI provides more details about cord compression, making the measurement more accurate and objective.

Relationship of actual laminoplasty opening size and increment of the cross-sectional area based on single-door cervical laminoplasy

BACKGROUND

Amounts of clinic research have been performed to investigate the increment of cross-sectional area in single-door cervical laminoplasty (SDCL). However, no one has taken the effects of surgery drill into consideration.

METHODS

A mathematical model was built to investigate the relation of actual laminoplasty opening size (LOS), the transverse canal diameter (TCD), and the increment of cross-sectional area in SDCL). The model was based on geometric analysis on deformation of spinal canal; the relation was derived and characterized as: (Equation is included in full-text article.), where a is the TCD, b the actual LOS, c the size of mini-plate, and d is diameter of the surgery drill bit. In the equation, the related variables would be measured to estimate the increment of cross-sectional area before the surgery. In the current research, 25 patients authorized to use their CT scans of C3∼C7 as the subject samples.

RESULTS

The effects of surgery SDCL were very significant; for each patient, the cross-sectional area was enlarged dramatically after the surgery (P < .01). On the contrary, the difference between the cross-sectional area obtained by the equation and that measured by software was statistically negligible (P > .05), which confirmed the reliability of the modeling equation.

CONCLUSIONS

Before the SDCL, increment of the cross-sectional area can be estimated by the above-mentioned modeling equation with a high-level reliability. This method ensures the optimum selection of mini-plate before operation for each patient.

A Novel Anterior Revision Surgery for the Treatment of Cervical Ossification of Posterior Longitudinal Ligament: Case Report and Review of the Literature

PURPOSE

A 62-year-old blind man with severe ossification of the posterior longitudinal ligament was presented. The patient underwent posterior laminectomy and fixation. After surgery, the patient was not satisfied with the recovery of his upper limbs although his Japanese Orthopedic Association (JOA) score had increased from 9 to 12 points. Because the tactile sensation of his hands was especially important to his daily life, the patient asked for further treatment after 6 months. This report describes the novel revision surgery we invented and the outcome in the patient after the surgery.

METHODS

We performed the revision surgery using an anterior approach from C3 to C7 with a novel technique, anterior controllable antedisplacement and fusion (ACAF). The patient was followed up for 6 months. The clinical data, including JOA score and radiologic images, were collected and analyzed.

RESULTS

After the revision surgery, the patient had improved sensation in both hands, and his JOA score increased to 14 points. Satisfactory decompression was assessed by magnetic resonance imaging after operation. Bone fusion was confirmed by computed tomography 3 months after operation. No specific complications related to this surgery were observed.

CONCLUSIONS

The application of such an operative procedure in revision surgery for OPLL has not been reported earlier and might be an alternative choice for patients with an unsatisfactory outcome from previous posterior surgery.

Radiological manifestations and surgical outcome of combined upper cervical cord compression and cervical ossification of the posterior longitudinal ligament with a minimum 2-year follow-up

Combined upper cervical cord compression associated with cervical ossification of the posterior longitudinal ligament (OPLL) is a rare and under-recognized disorder. The aim of this study was to investigate the radiological manifestations and surgical outcome of this combined disease.Between May 2011 and July 2015, patients who underwent surgery for combined upper cervical cord compression and cervical OPLL in our institution were included in this study. After a minimum 2-year follow-up, radiological and clinical data were collected. The etiology of upper cervical cord compression and radiological features of cervical OPLL was determined. Surgical outcome was evaluated with Visual Analogue Scale (VAS), Japanese Orthopedic Association score (JOA), space available for the spinal cord (SAC) at the cephalad adjacent level, occupying ratio of OPLL and cervical lordosis.In total, 24 patients (11 men and 13 women) with a mean age of 57.9 years old were included. The etiology of upper cervical cord compression included craniovertebral junction deformity (n = 10), atlantoaxial subluxation (n = 5), and OPLL extending to C2 level (n = 9). The extent, type, and thickest level of cervical OPLL varied among the patients. Significant improvement of VAS and JOA score was noted postoperatively and at a minimum 2-year follow-up. The result was satisfactory in SAC at the cephalad level and occupying ratio of OPLL. There were no significant differences in C2/C7 lordotic angle at the preoperative, postoperative and the last follow-up examination.In conclusion, the radiological manifestations of combined upper cervical cord compression and cervical OPLL varied among the patients. Satisfied results can be achieved with adequate surgical treatment a minimum 2-year follow-up.

Clinical outcome of laminoplasty for cervical ossification of the posterior longitudinal ligament with K-line (-) in the neck neutral position but K-line (+) in the neck extension position: A retrospective observational study

Patients with cervical ossification of the posterior longitudinal ligament (OPLL) who are K-line (-) are thought to have poor clinical outcomes after laminoplasty. The aim of this study is to compare the clinical results of patients with OPLL who were K-line (-) in the neck neutral position but K-line (+) in the neck extension position (NEP group) with patients with OPLL who were K-line (+) in the neck neutral position (NNP group).Retrospectively, 42 patients who underwent cervical laminoplasty for OPLL by our surgical group during 2012 and 2013 were reviewed and were followed for at least 2 years. The patients were divided into 2 groups according to K-line status. Standing plain radiographs of the cervical spine were obtained pre- and postoperatively. Cervical spine alignment parameters included the C2-7 Cobb angle and range of motion (ROM) measured on lateral radiographs. Clinical evaluation included pre- and postoperative JOA, NDI, and VAS scores.Ten patients were classified in the NEP group, and 32 patients were classified in the NNP group. Preoperatively, the OPLL involved segments were 4.10 ± 1.66 in the NEP group and 2.53 ± 1.16 in the NNP group (P = .005). The canal-occupying ratios were 58.40 ± 11.11% in the NEP group and 29.08 ± 11.38% in the NNP group (P < .001). The mean Cobb angle of both the groups had not changed significantly at the last follow-up. The mean cervical ROM of both the groups had decreased at the last follow-up. The mean JOA score of the NEP group improved significantly from 9.70 ± 2.16 to 12.50 ± 2.27 (P = .014). The mean JOA score of the NNP group improved significantly from 11.91 ± 1.69 to 14.93 ± 1.58 (P < .001). The mean JOA recovery rate was 32.71 ± 40.45% in the NEP group and 59.00 ± 33.80% in the NNP group (P = .036). The NDI scores of both groups were significantly decreased, and the VAS scores of both groups had not changed significantly at the last follow-up.Laminoplasty is a relatively effective and safe procedure for patients with K-line (-) in the neck neutral position but K-line (+) in the neck extension position. Instead of anterior surgery, we recommend laminoplasty for those patients with OPLL extending to 3 or more segments.

Anterior Cervical Corpectomy and Fusion Using a Synthetic Hydroxyapatite Graft for Ossification of the Posterior Longitudinal Ligament

The significant complication rate associated with harvesting autologous iliac bone or fibula has encouraged development of alternative graft substitutes. In this study, the authors investigated the efficacy and safety of synthetic porous hydroxyapatite (HA) combined with local vertebral bone graft for use in anterior cervical corpectomy and fusion (ACCF) for the treatment of patients with ossification of the posterior longitudinal ligament (OPLL). Since 2006, twenty-five OPLL patients underwent ACCF using HA blocks (HA group). Hydroxyapatite blocks with 40% porosity were used for the 1-level ACCFs, and HA blocks with 15% porosity were used for the 2-level ACCFs. Clinical and radiological evaluation was performed with a minimum of 2-year follow-up. Outcomes were compared with those of 25 OPLL patients who underwent ACCFs using auto-fibula grafts at the authors' institution before 2006 (FBG group). Patients' demographic data were similar in the HA and FBG groups. Both groups demonstrated significant neurological improvements postoperatively. No difference was observed in operating time, whereas the intraoperative blood loss was significantly less in the HA group. The fusion rates in the HA group were comparable to those in the FBG group. The incidences of general complications were similar in the 2 groups; however, prolonged donor-site pain was observed in 9 (36.0%) cases in the FBG group. Based on the results of this study, ACCF using HA is a safe and efficacious method for the treatment of patients with OPLL as an alternative to conventional ACCF using autologous fibula bone grafting. [Orthopedics. 2017; 40(2):e334-e339.].

Segmental Subtotal Corpectomy and Reconstruction With Titanium Cage and Anterior Plate for Multilevel Ossification of the Posterior Longitudinal Ligament

This retrospective study assessed the outcomes of segmental subtotal corpectomy with titanium cage reconstruction and anterior plate fixation for multilevel ossification of the posterior longitudinal ligament. The study included 34 patients with multilevel ossification of the posterior longitudinal ligament who underwent segmental subtotal corpectomy with titanium cage reconstruction and anterior plate fixation from June 2005 to May 2011. Clinical and radiologic data were obtained. Neurologic function was evaluated by Japanese Orthopedic Association scores before and after surgery. No death, paralysis, or other surgically associated injuries occurred. After surgery, the bone graft fusion was firm, with no cases of lack of postoperative bone fusion, broken or loose titanium plate and screws, dislodged titanium cage, or injury to the vertebral artery, nerve root, or spinal cord. Cerebrospinal fluid leakage occurred in 2 cases. Japanese Orthopedic Association scores improved from 6.74±1.82 preoperatively to 11.33±3.5 postoperatively (P<.05). Neurologic outcomes were excellent or good in 84.21% of patients at follow-up of 1 to 6 years. No postoperative cerebrospinal fluid leakage occurred. Reasonable and skilled operation of the pneumatic drill is the key to successful surgery. Anterior corpectomy with titanium cage reconstruction and plate fixation and drilling applications can directly remove the hypertrophy and ossification of the posterior longitudinal ligament and relieve spinal cord compression. This technique retained the integrity of the vertebrae, increasing the possibility of bone graft healing. Segmental subtotal corpectomy with titanium cage reconstruction and anterior plate fixation can be used for the treatment of multilevel ossification of the posterior longitudinal ligament. [Orthopedics. 2016; 39(6):e1140-e1146.].

[EFFECT OF SPINAL DURAL RELEASE ON TREATMENT OF MULTI-SEGMENTAL CERVICAL MYELOPATHY WITH OSSIFICATION OF POSTERIOR LONGITUDINAL LIGAMENT BY CERVICAL LAMINOPLASTY]

OBJECTIVE

To explore the effect of spinal dural release on the effectiveness of expansive cervical laminoplasty for treating multi-segmental cervical myelopathy with ossification of posterior longitudinal ligament.

METHODS

A retrospective analysis was made on the clinical data of 32 patients with multi-segmental cervical myelopathy with cervical ossification of posterior longitudinal ligament who underwent expansive cervical laminoplasty and spinal dural release between February 2011 and October 2013 (group A); and 36 patients undergoing simple expansive cervical laminoplasty between January 2010 and January 2011 served as controls (group B). There was no significant difference in gender, age, disease duration, affected segments, combined internal disease, preoperative cervical curvature, Japanese Orthopaedic Association (JOA) score, and visual analogue scale (VAS) score between 2 groups (P>0.05). Postoperative JOA score and improvement rate, VAS score, posterior displacement of the spinal cord, and the change of cervical curvature were compared between 2 groups.

RESULTS

Spinal dural tear occurred in 3 cases (2 cases in group A and 1 case in group B) during operation. Cerebrospinal fluid leakage occurred in 3 cases (2 cases in group A and 1 case in group B) after operation. The patients were followed up 12-46 months (mean, 18.7 months). At last follow-up, the JOA score and VAS score were significantly improved in 2 groups when compared with preoperative scores (P<0.05). JOA score and improvement rate of group A were significantly higher than those of group B (P<0.05), but VAS score of group A was significantly lower than that of group B (P<0.05). At last follow-up, no significant difference in cervical curvature was found between 2 groups (P>0.05); posterior displacement of the spinal cord of group A was significantly larger than that of group B (P<0.05). No reclosed open-door was observed during follow-up.

CONCLUSION

For patients with multi-segmental cervical myelopathy with ossification of posterior longitudinal ligament, full spinal dural release during expansive cervical laminoplasty can increase the posterior displacement of spinal cord, and significantly improve the effectiveness.

[Application of 360 degree circular decompression and transpedicle screw fixation in the treatment of ossification of thoracic posterior longitudinal ligament by posterior approach]

OBJECTIVE

To investigate the clinical effects of 360 degree circular decompression and transpedicle screw fixation to treat the ossification of thoracic posterior longitudinal ligament by posterior approach.

METHODS

From December 2009 to November 2013, 18 patients with ossification of thoracic posterior longitudinal ligament ossification were treated with 360 degree circle decompression and transpedicle screw fixation by posterior approach. There were 8 males and 10 females,ranging in age from 32 to 67 years old, with an average of 51 years old. Four patients were accompanied with ligamentum flavum ossification. Longitudinal ossifications in 5 cases were located in the upper thoracic vertebra and 13 cases in the middle and lower thoracic vertebra. Five cases were typical type, 4 cases were segmental type, 6 cases were continuous type and 3 cases were mixed type. All the patients had the posterior spinal canal decompression combined with longitudinal ligament resection, interbody fusion with bone graft and internal fixation surgeries. The operation time,blood loss and complications were recorded. JOA score were applied to evaluate the neurological function recovery pre-surgery, 2 days post-surgery and the latest follow-up. The surgery effects were evaluated by Epstein-Schwall method.

RESULTS

The operation time ranged from 3 to 6 hours (mean, 4.2 hours). The blood loss ranged from 800 to 4 000 ml (mean, 1 800 ml). All the patients were followed up, and the duration ranged from 6 months to 3 years, with a mean of 1.8 years. The JOA score increased from preoperative 4.30 ± 2.60 to 7.60 ± 2.40 2 days after surgery, and 7.80 ± 1.90 at the latest follow-up (t = 4.61, P < 0.001). The JOA scores between 2 days after surgery and the latest follow-up had no significant differences (t = 0.28,P = 0.78). The neurological recovery rate was 74% 2 days after surgery and 71% at the latest follow-up. There were 4 cases got an excellent result,10 good,3 fair and 1 poor according to Epstein-Schwall evaluation method. Four patients had cerebrospinal fluid leakage, 3 patients had intercostal nerve paralysis or pain, and 1 patient had superficial incision infection. The neurological function in 3 patients became worse in the second day posteratively , and among them, 2 patients were recovered at the latest follow-up and 1 patient had no changes. All the patients got fusion of bone graft and no internal fixation loosening and fractures occurred.

CONCLUSION

360 degree circular decompression and transpedicle screw fixation can resect different types of thoracic longitudinal ligament ossification, and can achieve a good clinical effect.

Mid- to long-term outcomes of posterior decompression with instrumented fusion for thoracic ossification of the posterior longitudinal ligament

Posterior decompression with instrumented fusion (PDF) surgery has been previously reported as a relatively safe surgical procedure for any type of thoracic ossification of the longitudinal ligament (OPLL). However, mid- to long-term outcomes are still unclear. The aim of the present study was to elucidate the mid- to long-term clinical outcome of PDF surgery for thoracic OPLL patients. The present study included 20 patients who had undergone PDF for thoracic OPLL and were followed for at least 5years. Increment change and recovery rate of the Japanese Orthopaedic Association (JOA) score were assessed. Revision surgery during the follow-up period was also recorded. Average JOA scores were 3.5 preoperatively and 7.1 at final follow-up. The average improvement in JOA score was 3.8 points and the average recovery rate was 47.0%. The JOA score showed gradual increase after surgery, and took 9months to reach peak recovery. As for neurological complications, two patients suffered postoperative paralysis, but both recovered without intervention. Six revision surgeries in four patients were related to OPLL. Additional anterior thoracic decompression for remaining ossification at the same level of PDF surgery was performed in one patient. Decompression surgery for deterioration of symptoms of pre-existing cervical OPLL was performed in three patients. One patient had undergone lumbar and cervical PDF surgery for de novo ossification foci of the lumbar and cervical spine. PDF surgery for thoracic OPLL is thus considered a relatively safe and stable surgical procedure considering the mid- to long-term outcomes.

A circumferential decompression-based surgical strategy for multilevel ossification of thoracic posterior longitudinal ligament

BACKGROUND CONTEXT

Multilevel ossification of posterior longitudinal ligament (OPLL) at thoracic spine can be simultaneously symptomatic. Different approaches for thoracic decompression have been reported, among which circumferential decompression (CD) seems promising but is invasive, so methods to find approaches indicating levels for CD are also important.

PURPOSE

This study aimed to introduce a CD-based surgical strategy for multilevel thoracic OPLL and describe its clinical outcomes.

STUDY DESIGN

A retrospective clinical study was used.

PATIENT SAMPLE

A cohort of 26 patients were recruited, whose average age was 51.2±9.1 years old.

OUTCOME MEASURES

A modified Japanese Orthopedic Association (JOA) scale for thoracic spine was used to evaluate neurologic status, and final recovery rates were assessed according to Hirabayashi system.

METHODS

Posterior decompression was initially performed for all compressive levels, whereas CD levels were decided through combined modalities, of which intraoperative ultrasound was an important determinant. All patients were regularly followed for more than 2 years.

RESULTS

The average operative duration and blood loss were 279.3±54.8 minutes and 2257.7±1443.9 mL, respectively. There were 17 patients (65.4%) who achieved instant improvement and 9 (34.6%) neurologically deteriorated. Cerebrospinal fluid leakage occurred in 10 patients (38.5%), but its occurrence did not affect the final neurologic recovery. Other complications included urinary infection, incision infection and disunion, lung infection, and subcutaneous fluid collection. Late events included death from cerebrovascular accident, pseudomeningocele, unremitted intercostal pain and continuing deterioration. The final JOA score and recovery rate were correlated with OPLL levels and preoperative JOA scores (p<.05). Eventually, the average JOA score was significantly elevated from 4.5±1.8 to 8.3±2.3 (p<.05), with the recovery rate of 11 patients rated as excellent, 7 as good, 6 as fair, and 2 as unchanged or deteriorated. The average recovery rate was 60.4%.

CONCLUSIONS

This CD-based surgical strategy was effective for multilevel thoracic OPLL and had fair late outcomes, but its postoperative courses were quite eventful. Intraoperative ultrasound was a reliable modality to determine CD levels.

Ossified Posterior Longitudinal Ligament With Massive Ossification of the Anterior Longitudinal Ligament Causing Dysphagia in a Diffuse Idiopathic Skeletal Hyperostosis Patient

Descriptive case report.To report a case of a diffuse idiopathic skeletal hyperostosis (DISH) patient with both massive ossification of the anterior longitudinal ligament (OALL) leading to severe dysphagia as well as ossification of the posterior longitudinal ligament (OPLL) causing mild cervical myelopathy, warranting not only an anterior approach but also a posterior one.Although DISH can cause massive OALL in the cervical spine, severe dysphagia resulting from DISH is a rare occurrence. OALLs are frequently associated with OPLL. Treatment for a DISH patient with OPLL in setting of OALL-caused dysphagia is largely unknown.A 70-year-old man presented with severe dysphagia with mild cervical myelopathy. Neurological examination showed mild spastic paralysis and hyper reflex in his lower extremities. Plane radiographs and computed tomography of the cervical spine revealed a discontinuous massive OALL at C4-5 and continuous type OPLL at C2-6. Magnetic resonance imaging revealed pronounced spinal cord compression due to OPLL at C4-5. Esophagram demonstrated extrinsic compression secondary to OALL at C4-5.We performed posterior decompressive laminectomy with posterior lateral mass screw fixation, as well as both resection of OALL and interbody fusion at C4-5 by the anterior approach. We performed posterior decompressive laminectomy with posterior lateral mass screw fixation, as well as both resection of OALL and interbody fusion at C4-5 by the anterior approach. Severe dysphagia markedly improved without any complications.We considered that this patient not only required osteophytectomy and fusion by the anterior approach but also required decompression and spinal fusion by the posterior approach to prevent both deterioration of cervical myelopathy and recurrence of OALL after surgery.

[A Case Report of the Postoperative Epidural Hematoma the Cause of Which Was Thought to Be the Spinal Abnormality]

Although an 84-year-old patient did not have any coagulopathy and there was no vascular injury at the time of epidural puncture, epidural hematoma developed late in onset Ossification of the posterior longitudinal ligament of the spine was suspected as a potential cause. The vascular hyperplasia in the epidural space is possible in a case of ossification of the posterior longitudinal ligament of the spine. A careful observation is necessary after the epidural catheter insertion in a patient with ossification of the posterior longitudinal ligament.

A novel skull clamp positioning system and technique for posterior cervical surgery: clinical impact on cervical sagittal alignment

A prospective radiographic study.The purpose of this study was to analyze whether a novel skull clamp positioning system and technique is useful for obtaining good, quantitative cervical sagittal alignment during posterior cervical surgery.Different surgical procedures depend on cervical spine positioning. However, maneuver of the device and cervical position depends on the skill of the operator.This study included 21 male and 10 female patients with cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament of the cervical spine, undergoing posterior cervical surgery using the novel skull clamp positioning system. The average patient age was 68.6 years (range: 56-87 years). The novel system has a scale to adjust the neck position and to enable intended cervical sagittal alignment. First, the patient was placed on the operating table in the prone position with preplanned head-neck sagittal alignment (neutral position in general). The head was rotated sagittally, and the head was positioned in the military tuck position with the novel device that was used to widen the interlaminar space. After completing the decompression procedure, the head was rotated again back to the initial preplanned position. During this position change, the scale equipped with the device was useful in determining accurate positions. The C0-C1, C0-C2, C1-C2, C2-C7, and C0-C7 angles were measured on lateral radiographs taken pre-, intra-, and postoperatively.This novel system allowed us to obtain adequate, quantitative cervical sagittal alignment during posterior cervical surgery. There were no clinically significant differences observed between the pre- and postoperative angles for C1-C2 and C2-C7.Sagittal neck position was quantitatively changed during posterior cervical surgery using a novel skull clamp positioning system, enabling adequate final cervical sagittal alignment identical to the preplanned neck position.

Benefit of degenerative posterior longitudinal ligament removal during anterior decompression in cervical spondylotic myelopathy

It remains controversial whether degenerative posterior longitudinal ligaments should be removed during anterior decompression procedures for cervical spondylotic myelopathy. Few data are available from studies that have compared removing and retaining the degenerative posterior longitudinal ligament. The goal of this retrospective study was to evaluate the benefit of degenerative posterior longitudinal ligament removal during such operations. Clinical data on 130 patients with confirmed degenerative posterior longitudinal ligament who underwent anterior cervical decompression surgery were retrospectively reviewed. All procedures were performed by the same senior orthopedic surgeon at the authors' spinal surgery center. The degenerative posterior longitudinal ligament was removed in 62 patients (group A) and retained in 68 patients (group B). The 130 patients were followed for 36 months. The Japanese Orthopedic Association score improved from 9.0±2.7 to 14.7±1.5 in group A and from 9.4±2.6 to 14.1±1.7 in group B (P=.028). The recovery rate for spinal cord neurologic function was 66.7% in group A and 61.3% in group B (P=.031). Operating time was longer (P=.002) and the sagittal median diameter of the vertebral canal was enhanced in group A (P<.001). Narrowing of previously enlarged canals occurred at a significantly higher rate in group B (P=.044). No significant difference was found in the rates of common complications between groups. Removal of the degenerative posterior longitudinal ligament in anterior decompression procedures for cervical spondylotic myelopathy appeared to be beneficial and provided more complete decompression and better postoperative outcomes than surgery without removal of the ligament. Although this procedure was generally safe, it required longer operating times, was more technically challenging, and required more experienced surgeons than surgery without removal of the ligament.

Surgical results and prognostic factors of anterior cervical corpectomy and fusion for ossification of the posterior longitudinal ligament

Background

Mechanism of ossification of the posterior longitudinal ligament (OPLL) has not been elucidated clearly. Surgical decompression is usually necessary for the patients with neurological symptoms. Anterior decompression and resection of OPLL seems to be a radical surgical option, because the spinal cord is compressed from the anterior direction.

Methods

Among 229 patients who underwent ACF for OPLL between January 2001 and December 2007 in our hospital, a total of 133 patients responded to the invitation and made return visits, with a follow-up rate of 58.1%. For these patients, clinical data were collected from medical and operative records. Neurological status were evaluated by using the Japanese Orthopedic Association (JOA) scoring system. Radiological evaluations including C2-7 lordotic angle, sagittal vertical axis (SVA), occupying rate of OPLL, double-layer sign and high-intensity zone were obtained from all the patients. Complications and causes of revision surgery were also investigated. Correlations between the long-term surgical outcome and various prognostic factors were statistically analyzed.

Findings

Eighty-four males and forty-nine females completed the follow-up, with a mean age at operation of 56.8 years. The overall average JOA score significantly increased, with a mean recovery rate of 64.1%±14.2%. The mean C2-7 lordotic angle and SVA were also significantly improved, and fusion rate was satisfactory. The incidence of complications was consistent to the previous reports and most of them were controllable by suitable treatments. Multiple regression analysis showed that number of corpectmies and preoperative JOA score were important predictors of surgical outcome.

Conclusions

ACF is a reliable and effective method for treating OPLL patients in terms of neurological recovery, maintenance of radiological parameters, fusion rate and complications. Number of corpectomies and preoperative JOA score are important predictors for the clinical outcome when this procedure is used.

Anterior longitudinal decompression in the management of severe ossification of the posterior longitudinal ligament in the cervical spine

The advantages of anterior surgery for severe ossification of the posterior longitudinal ligament in the cervical spine have been reported. However, it is more technically demanding and associated with a high risk of surgery-related complications. The purpose of this study was to evaluate the feasibility of longitudinal decompression techniques in anterior surgery for severe ossification of the posterior longitudinal ligament in the cervical spine. Between June 2008 and December 2011, twenty-two patients (16 men and 6 women; average age, 58 years [range, 45-72 years]) who underwent anterior corpectomy and fusion for severe ossification of the posterior longitudinal ligament were studied retrospectively. The clinical efficacy, canal narrowing ratio, fused segment height, and complications were investigated. After a mean 25.4-month follow-up, mean Japanese Orthopaedic Association score increased from 8.8±1.4 preoperatively to 14.0±1.2 at final follow-up (P<.05), an improvement rate of 63.5%±12.5%. Mean canal narrowing ratio decreased from 62.0%±6.0% preoperatively to 8.2%±4.9% postoperatively (P<.05). Mean fused segment height increased 2.3±0.5 mm from pre- to postoperatively and decreased 2.8±0.4 mm from postoperatively to final follow-up (P>.05). Five patients developed cerebrospinal fluid leakage, and 1 patient experienced hematoma. No instrument failure was observed, and all patients had successful fusion. Anterior longitudinal decompression is a relatively effective procedure in the management of severe ossification of the posterior longitudinal ligament in the cervical spine. It can be applied to treat closed-base ossification of the posterior longitudinal ligament (defined as no space between the lateral margin of the ossified base and the spinal canal lateral wall), but it is associated with a high risk of cerebrospinal fluid leakage.

Circumferential decompression via the posterior approach for the surgical treatment of multilevel thoracic ossification of the posterior longitudinal ligaments: a single institution comparative study

BACKGROUND

The treatment strategies for multilevel thoracic ossification of the posterior longitudinal ligaments (T-OPLL) were rarely reported. The aim of this study was to investigate the clinical outcomes and complications of circumferential decompression for multilevel T-OPLL and compare two different methods in the management of the OPLL (resection or floating).

METHODS

Data of sequentially treated patients who received surgical treatment for thoracic spinal stenosis caused by multilevel T-OPLL from January 2005 to February 2012 were retrospectively reviewed. Based on the surgical approaches applied, the patients were divided into two groups. Group A consisted the patients who received posterior decompression and group B consisted the patients who received circumferential decompression via the posterior approach. Group B was further divided into two subgroups: subgroup 1 (the resection group) where the OPLL was completely resected and subgroup 2 (the floating group) where the OPLL was floated.

RESULTS

A total of 49 patients were included in the study. Fourteen patients with single posterior decompression were included in group A and 35 patients who received circumferential decompression were included in group B. In group B, 29 patients had complete resection of the ossified posterior longitudinal ligaments, while the other six underwent a flotation procedure. The follow-up data were available in 39 patients. Mean JOA scores improved from 5.4 ± 1.8 to 7.5 ± 2.8 in group A and from 3.7 ± 1.8 to 7.9 ± 2.4 in group B. The main complications included cerebrospinal fluid (CSF) leakage and postoperative neurologic deterioration (ND). Twenty-three of the 25 cases with postoperative CSF leakage achieved a complete recovery at the last follow-up and 12 of the 15 cases with ND achieved some neurological improvement at the last follow-up.

CONCLUSIONS

Circumferential decompression via the posterior approach is an effective surgical method for thoracic spinal stenosis caused by multilevel OPLL of the thoracic spine. Patients who receive complete resection of the ossified posterior longitudinal ligaments may have better recovery rate than the "floating" group.

Computer-assisted minimally invasive spine surgery for resection of ossification of the ligamentum flavum in the thoracic spine

BACKGROUND

Ossification of the ligamentum flavum (OLF) has been widely recognized as one of the main causes of thoracic spinal canal stenosis and thoracic myelopathy. Decompression is the only effective strategy for treating thoracic myelopathy caused by OLF. The purpose of this study was to describe the clinical outcomes of computer-assisted minimally invasive spine surgery (CAMISS) for posterior decompression in patients with thoracic myelopathy caused by OLF.

METHODS

In all cases, the surgical procedure was performed with the assistance of an intraoperative three-dimensional navigation system. Decompression of the spinal cord was performed with a high-speed drill; the supraspinal ligaments and spinous process were partially preserved. The outcomes were evaluated by a modified Japanese Orthopedic Association (JOA) scoring system and recovery rates.

RESULTS

The mean duration of follow-up for the 14 cases was 3.9 years. All patients experienced neurological recovery, the mean JOA score improving from 6.1 points preoperatively to 8.6 points at final follow-up and the mean rate of recovery being 52.7% (excellent in two cases, good in eight, fair in three, and unchanged in one).

CONCLUSION

CAMISS is a safe and effective procedure for resection of the OLF in the thoracic spine.

Clinical results and intramedullary signal changes of posterior decompression with transforaminal interbody fusion for thoracic myelopathy caused by combined ossification of the posterior longitudinal ligament and ligamentum flavum

BACKGROUND

Surgical treatment of thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF) is technically demanding, and the results tend to be unfavorable. Various operative approaches and treatment strategies have been attempted, and posterior decompression with transforaminal thoracic interbody fusion (PTTIF) may be the optimal method with which the anterior-posterior compression was removed in one step. It is comparatively less traumatic with fewer serious complications.

METHODS

Sixteen patients with thoracic myelopathy due to concurrent OLF and OPLL at the same level underwent PTTIF. We investigated clinical outcomes and neurological improvements. Magnetic resonance imaging (MRI) was performed on all patients preoperatively and postoperatively, and intramedullary signal changes were evaluated.

RESULTS

The mean operating time was 275 minutes, and the mean operative bleeding amount was 1031 ml. Cerebrospinal fluid leakage occurred in three patients and healed well after repair. Neurological symptom deterioration occurred in one patient, but the patient recovered to nearly the preoperative level after methylprednisolone treatment. The follow-up period ranged from 28 to 47 months. The mean score on the Japanese Orthopedic Association scale improved from 4.3±1.2 preoperatively to 7.3±1.7 at 3 months postoperatively to 8.5±1.5 at the final follow-up (P < 0.01), with a recovery rate of (63.6±20.0)%. Postoperative images showed a significant improvement in local kyphosis (P < 0.01). Eleven patients (68.8%) showed increased signal intensity (ISI) on preoperative T2-weighted MRI. At the final follow-up, the intramedullary ISI totally recovered in five patients. Neurological improvement was worse in patients with persistent ISI than in the other patients (P < 0.05).

CONCLUSIONS

PTTIF is an effective therapeutic option for combined OPLL and OLF and provides satisfactory neurological recovery and stabilized thoracic fusion through a single posterior approach. Intramedullary signal changes do not always indicate a poor prognosis; only irreversible ISI is correlated with a poor clinical result.

[Discussion of surgical indications for posterior expansive open-door laminoplasty extended to C1 level]

OBJECTIVE

To determine the surgical indications for posterior expansive open-door laminoplasty (EOLP) extended to the C1 level.

METHODS

Seventeen patients undergoing C3-7 or C2-7 open-door laminoplasty were included as the case group between September 2005 and January 2010, whose spinal cord injury symptoms were not alleviated or aggravated again because of the cervical stenosis at C-4 level, and the causes of the surgery itself were eliminated, all of these patients underwent reoperation with decompress upward to C1 level. Fifteen patients with cervical stenosis who underwent C2-7 laminoplasty and C1 laminectomy were selected as the control group. There was no significant difference in gender, age, and disease duration between 2 groups (P > 0.05). The pre- and post-operative cervical curvature and spinal cord compression were evaluated according to the patients' imaging data; the pre- and post-operative neurological recovery situation was evaluated by Japanese Orthopaedic Association (JOA) 17 score and spinal cord function Frankel grade; the neurological recovery rate (according to Hirabayashi et al. method) was used to assess the postoperative neurological recovery situation.

RESULTS

In the case group, 8 patients underwent primary C37 laminoplasty. In 3 of these patients, there was a cervical stenosis at C1, 2 level, and discontinuous cerebrospinal fluid around the spinal cord was observed; 5 of them with a compression mass which diameter was exceed 7.0 mm in the C2-4 segments. The remaining 9 patients in the case group underwent primary C2-7 laminoplasty, and the diameter of the compression mass was exceed 7.0 mm in the C2-4 segments. In all 17 patients of the case group, reoperation was performed with the decompression range extended to the C1 level, and the follow-up time was 35-61 months with an average of 45.6 months. Cervical curvature: there were 11 cases of cervical lordosis, 4 cases of straight spine, and 2 cases of cervical kyphosis before operation; but after operation, 2 cases of cervical lordosis became straight spine and 1 straight case became kyphosis. The postoperative neurological improvement was excellent in 8 cases, good in 7, and fair in 2. In the control group, all the patients had a compression mass which anteroposterior diameter was exceed 7.0 mm in the C2-4 segments before operation. The follow-up time was 30-58 months with an average of 38.7 months. Cervical curvature: there were 13 cases of cervical lordosis and 2 cases of straight spine before operation; but after operation, 1 case of cervical lordosis became straight spine. The postoperative neurological improvement was excellent in 8 cases, good in 6, and fair in 1. No significant difference was found in the JOA score at pre- and post-operation between 2 groups (P > 0.05); however, there were significant differences (P < 0.05) in the JOA score between at last follow-up and at preoperation.

CONCLUSION

The initially surgical indications which can be used as a reference for EOLP extended to C1 are as follows: (1) Upper cervical (C1, 2) spinal stenosis: C1 posterior arch above the lower edge part of cerebrospinal fluid around the spinal cord signal is not continuous, and the anteroposterior diameter of the spinal canal actual is less than 8.0 mm as judgment standard. (2) There is a huge compression at the lower edge of C2-4 vertebrae, and the most prominent part of the diameter is exceed 7.0 mm, which can not be removed through the anterior cervical surgery, or the operation is high-risk.