Exclusion of Ossified Ligaments Behind C2 Vertebra Combined with Anterior Controllable Antedisplacement and Fusion for Cervical Ossification of the Posterior Longitudinal Ligament Extending to C2 Segment.

OBJECTIVE: We sought to introduce an anterior surgical technique for cervical ossification of posterior longitudinal ligament (OPLL) extending to C2. METHODS: A total of 29 patients with multilevel OPLL extending to C2 underwent surgery from January 2016 to January 2019. The rationale of our surgical technique is to transect the ossified ligament at the level of C2/3, dividing OPLL into 2 parts. OPLL behind the C2 vertebra is reserved as "focus exclusion," and OPLL below C2 is performed anterior controllable antedisplacement and fusion. Neurologic condition was evaluated using the Japanese Orthopaedic Association scoring system and its improvement ratio. Radiologic assessment included type and extent of OPLL, occupying rate, thickness and length of ossified mass, and curvature of spinal cord. Surgery- and implant-related complications were recorded. RESULTS: The mean Japanese Orthopaedic Association score increased from 9.4 to 15.8 points at last follow-up, with a significant improvement (P < 0.01). The mean preoperative length of the ossified mass behind C2 was 15.4 mm, and its thickness was 2.2 mm, with no significant progression at last follow-up (15.3 mm and 2.2 mm, P > 0.05). There was also no statistical difference in OPLL thickness at the largest occupying rate level between preoperation and last follow-up (7.4 mm vs. 7.3 mm, P > 0.05). Four patients presented with cerebrospinal fluid leakage, 1 with screw displacement, and 1 with dysphagia. CONCLUSIONS: For patients with cervical OPLL extending to C2, exclusion of ossified ligaments behind C2 combined with anterior controllable antedisplacement and fusion below C2 is an effective and alternative technique.

Skip corpectomy and fusion (SCF) versus anterior controllable antedisplacement and fusion (ACAF): which is better for patients with multilevel cervical OPLL?

BACKGROUND: The aim of this study was to compare the clinical efficacy and radiological outcomes of skip corpectomy and fusion (SCF) with anterior controllable antedisplacement and fusion (ACAF) for treating multilevel ossification of the posterior longitudinal ligament (OPLL). METHODS: 62 patients with multilevel OPLL who had undergone SCF or ACAF were analyzed retrospectively. Types of OPLL, occupying ratio (OR), Japanese Orthopaedic Association (JOA) score, Recovery Rate (RR), Neck Disability Index (NDI) score, Cobb's angles of C2-C7, operation time, blood loss, hospital stay, ratings for fusion assessment and complications were recorded and assessed. RESULTS: Postoperative C2-C7 Cobb's angle (11.1 ± 3.2° vs. 13.7 ± 2.5°; P < 0.05), NDI scores at final follow-up (14.3 ± 1.6 vs. 13.3 ± 1.3; P < 0.05), and rate of cerebral fluid (CSF) leakage (5, 16.7% vs. 0,0%; P < 0.05) were significantly better in the ACAF group. At 6 months, bone graft fusion rate was significantly greater in the ACAF group (24.75% vs. 15.50%; P < 0.05). CONCLUSIONS: Surgical treatment of multilevel OPLL by SCF or ACAF showed no significant differences in clinical outcomes, with the exception of better NDI scores at final follow-up in ACAF. In addition, ACAF is better than SCF in terms of early bone graft fusion rate, lordotic curvature improvement, risk of CSF leakage.

Anterior Controllable Antedisplacement Fusion for Multilevel Cervical Spondylotic Myelopathy with Spinal Stenosis: Comparison with Anterior Cervical Corpectomy and Fusion.

OBJECTIVE: To introduce anterior controllable antedisplacement fusion (ACAF), a new surgical technique, to treat multilevel cervical spondylotic myelopathy with spinal stenosis and compare ACAF with anterior cervical corpectomy and fusion (ACCF). METHODS: Patients with multilevel cervical spondylotic myelopathy with spinal stenosis who underwent ACAF (36 cases) and ACCF (45 cases) from January 2016 to June 2017 were enrolled in this study. Japanese Orthopaedic Association score was analyzed before the operation and at each scheduled follow-up during the follow-up period after surgery to evaluate neurologic function. Clinical and radiologic outcomes and perioperative complications were analyzed. RESULTS: At the final follow-up, mean Japanese Orthopaedic Association scores of the 2 groups were significantly improved compared with preoperatively (P < 0.01 and P < 0.01). However, mean Japanese Orthopaedic Association scores between the 2 groups were not statistically significant (13.7 ± 1.9 vs. 13.5 ± 1.8, P = 0.66). Operative duration was longer and blood loss was greater in the ACAF group compared with the ACCF group. Overall occurrence of complications in the ACAF group was significantly lower compared with the ACCF group (P < 0.05). CONCLUSIONS: ACAF has similar clinical and radiologic outcomes and fewer complications compared with ACCF in treatment of multilevel cervical spondylotic myelopathy with spinal stenosis. ACAF can be used as an alternative treatment for cervical stenosis.

Anterior controllable antedisplacement fusion as a choice for 28 patients of cervical ossification of the posterior longitudinal ligament with dura ossification: the risk of cerebrospinal fluid leakage compared with anterior cervical corpectomy and fusion.

PURPOSE: To compare the incidence rate of cerebrospinal fluid (CSF) leakage between anterior controllable antedisplacement fusion (ACAF) and anterior cervical corpectomy and fusion (ACCF) in the treatment of ossification of the posterior longitudinal ligament (OPLL) with dura ossification (DO). METHODS: In the period from June 2015 to June 2017, ACAF and ACCF were performed on patients with OPLL with DO. Double-layer sign was observed on axial bone window of CT images. The operation duration, blood loss, and hospital stay were measured. Radiologic assessment included occupying rate, type and extent of OPLL, decompression width, postoperative area of the spinal canal, and anteroposterior diameter of the spinal cord. The JOA scoring system was used to evaluate the neurological status. Surgery-related complications such as CSF leakage and spinal cord or nerve injury were all recorded. RESULTS: There were 28 patients in ACAF group and 31 in ACCF group. On cross-sectional CT, decompression width and postoperative spinal canal area were both significantly larger in the ACAF group than that in the ACCF group (P < 0.01). The anteroposterior diameter of the spinal cord was significantly larger in the ACAF group (P < 0.05). Mean JOA score was better in the ACAF group (P < 0.05). In the ACCF group, seven (22.6%) patients had CSF leakage. However, only one (3.6%) presented with CSF leakage in the ACAF group. The difference of incidence rate of CSF leakage was significant (P < 0.01). CONCLUSIONS: ACAF, which can significantly reduce CSF leakage and achieve good neurological recovery, is a good option to treat cervical OPLL with DO. These slides can be retrieved under Electronic Supplementary Material.

Anterior Controllable Antedisplacement Fusion as a Choice for Ossification of Posterior Longitudinal Ligament and Degenerative Kyphosis and Stenosis: Postoperative Morphology of Dura Mater and Probability Analysis of Epidural Hematoma Based on 63 Patients.

OBJECTIVE: We studied the postoperative morphology of the dura mater and analyzed the probability of epidural hematoma (EH) after anterior controllable antedisplacement and fusion (ACAF). METHODS: A total of 63 patients with a diagnosis of ossification of the posterior longitudinal ligament (OPLL) and degenerative kyphosis and stenosis (DKS) had undergone ACAF from 2016 to 2017. All these patients had undergone cervical plain films, computed tomography, and magnetic resonance imaging (MRI). The operation duration, blood loss, and hospital stay were estimated. Radiological assessments included the occupying rate, OPLL type and extent, kyphotic angle, decompression width, and postoperative area of the spinal canal. On sagittal MRI, the postoperative morphology of dura mater was observed. The Japanese Orthopaedic Association scoring system was used to evaluate neurological status. EH and other surgery-related complications were recorded. RESULTS: Of the 63 patients, 39 had OPLL and 24 had DKS. All the patients were followed up for 3-18 months (average, 12.5). The mean decompression width and postoperative spinal canal area were 18.7 ± 1.1 mm and 167.7 ± 34.6 mm2 in the OPLL group and 17.9 ± 0.9 mm and 263.1 ± 46.9 mm2 in the DKS group, respectively. On sagittal MRI, the dura mater was classified into 4 types according to its morphology (dune, ladder, wave, and mixed type), protecting the spinal cord as would a suspensory tent. No patient presented with EH. The mean postoperative Japanese Orthopaedic Association score at the last follow-up examination was significantly better than preoperatively. CONCLUSIONS: The dura mater can protect the spinal cord like a suspensory tent after ACAF. The occurrence of EH is rare when ACAF is used to treat OPLL and DKS.

Anterior Controllable Antedisplacement Fusion as a Choice for Degenerative Cervical Kyphosis with Stenosis: Preliminary Clinical and Radiologic Results.

OBJECTIVE: The optimal surgical procedure for degenerative cervical kyphosis with stenosis (DCKS) remains controversial. The purpose of this study is to describe the preliminary clinical and radiologic results of anterior controllable antedisplacement fusion (ACAF) as a surgical technique for DCKS. METHODS: In the period from 2016 through 2017, a consecutive cohort of adults with degenerative cervical kyphosis (30° ≥ Cobb angles ≥5°) and stenosis (anteroposterior diameter of the spinal canal <12 mm) underwent ACAF, a technique making the vertebrae move forward in a hoisting manner. We retrospectively reviewed these patients, and primary outcomes of interest included operation duration, blood loss, hospital stay, kyphosis correction, decompression width, anteroposterior diameter of the spinal canal, morphology of the spinal cord, Japanese Orthopaedic Association (JOA) scores, and complications. RESULTS: Thirty patients were included in the study. All patients were followed for a mean of 12 months. Mean operation duration and estimated blood loss were 104.8 minutes and 221.6 mL, respectively, and the mean length of hospital stay was 5.6 days. The decompression width reached 17.7 mm. The postoperative anteroposterior diameter of the spinal canal was 14.8 mm, with a significant improvement compared with preoperation (P < 0.01). There was also significant kyphosis correction after operation (20.4° vs. 4.8°, P < 0.01). The mean JOA score was significantly better than preoperation (15.0 vs. 9.3 points; P < 0.01). There were no surgery-related complications. CONCLUSIONS: ACAF, correcting cervical kyphosis and simultaneously enlarging the volume of the spinal canal, is a good choice for DCKS.

Surgical results and complications of anterior controllable antedisplacement fusion as a revision surgery after initial posterior surgery for cervical myelopathy due to ossification of the posterior longitudinal ligament.

Posterior surgery has been widely used as an initial surgery for cervical ossification of the posterior longitudinal ligament (OPLL). However, some patients require revision surgery because of failure of symptom relief or late neurological deterioration after posterior surgery. The aim of this study is to retrospectively investigated the surgical results and complications of anterior controllable antedisplacement fusion (ACAF) as a revision surgical technique after initial posterior surgery for OPLL. The present study concluded 13 patients. The operation duration, blood loss and hospital stay was estimated. Radiologic assessment included type and extent of OPLL, decompression width and antero-posterior (AP) diameter of the spinal cord. The JOA scoring system was used to evaluate the neurological status. Surgery- and implant-related complications such as cerebrospinal fluid (CSF) leakage, spinal cord or nerve injury, subsidence and pseudoarthrosis were all recorded. The results showed that nine patients undergoing revision ACAF because of residual stenosis after initial posterior surgery, two because of OPLL progression, one because of lamina closure, one because of a blind man requiring better neurological function of both hands. The mean decompression width and AP diameter of the spinal cord was 20.3 ±â€¯2.1 mm and 5.8 ±â€¯1.1 mm respectively. The mean postoperative JOA score at last follow-up was significantly better than preoperation (14.8 ±â€¯2.5 vs. 8.5 ±â€¯2.7 points, P < 0.01), with a mean improvement rate of 75.3% ±â€¯12.2%. No complication such as CSF leakage, spinal cord or nerve injury, subsidence and pseudoarthrosis occurred. In conclusion, ACAF is a well choice for revision surgery after initial posterior surgery for OPLL.

Anterior Controllable Antedisplacement Fusion (ACAF) for Severe Cervical Ossification of the Posterior Longitudinal Ligament: Comparison with Anterior Cervical Corpectomy with Fusion (ACCF).

OBJECTIVE: Anterior cervical corpectomy and fusion (ACCF), in which a ventral constriction is resected, can decompress myelopathy and is considered the optimal treatment for ossification of the posterior longitudinal ligament (OPLL) up to now. However, its disadvantages are incomplete decompression, high surgery- and implant-related complication rates, and extremely surgical technique demanding. Our object was to introduce anterior controllable antedisplacement fusion (ACAF), a new surgical technique to treat OPLL, and compare it with ACCF. METHODS: ACAF was performed on 34 patients with spinal stenosis with myelopathy due to severe (occupying rate ≥50%) OPLL. Pre- and postoperatively, we measured decompression width and spinal canal area on cross-sectional computed tomography and morphology and anteroposterior diameter of the spinal cord at the most severely affected segment on cross-sectional magnetic resonance imaging and cross-sectional computed tomography. Japanese Orthopedic Association scoring was used to evaluate neurologic status. The ACAF group and a control group of 36 patients with ACCF were compared. RESULTS: Postoperatively, decompression width (17.9 ± 1.0 vs. 15.1 ± 0.8 mm; P < 0.01), spinal canal area (150.4 ± 31.6 vs. 127.0 ± 27.0 mm2; P < 0.01), and anteroposterior spinal cord diameter (5.4 ± 0.6 vs. 5.0 ± 1.1 mm; P < 0.05) were significantly greater in the ACAF group. At 6 months, mean Japanese Orthopedic Association score was significantly better in the ACAF group (15.4 ± 0.9 vs. 14.5 ± 2.5 points; P = 0.04). CONCLUSIONS: ACAF, providing adequate decompression of the spinal cord and good outcomes, is a well choice in the treatment of spinal stenosis due to severe OPLL.

In Situ Decompression to Spinal Cord During Anterior Controllable Antedisplacement Fusion Treating Degenerative Kyphosis with Stenosis: Surgical Outcomes and Analysis of C5 Nerve Palsy Based on 49 Patients.

OBJECTIVE: To observe outcomes of anterior controllable antedisplacement fusion (ACAF) in treatment of degenerative kyphosis with stenosis (DKS) and analyze probability of C5 nerve palsy. METHODS: From 2016 to 2017, a consecutive cohort of adults with DKS underwent ACAF. All patients underwent cervical radiography, computed tomography, and magnetic resonance imaging. Operative duration, blood loss, and hospital stay were estimated. Radiologic assessment included kyphotic correction, decompression width, and spinal canal area. Postoperative curvature of spinal cord was observed on sagittal magnetic resonance imaging. Japanese Orthopaedic Association score was used to evaluate neurologic status. C5 nerve palsy and other complications were recorded. RESULTS: The study included 49 patients. There was significant kyphosis correction postoperatively (-19.4° vs. 3.5°, P < 0.01). On cross-sectional computed tomography, mean decompression width was 19.0 mm, and spinal canal area was 218.5 mm2. On sagittal magnetic resonance imaging, spinal cord curvature was classified into 5 types: type I, lordosis; type II, straight with no shifting; type III, straight with shifting; type IV, sigmoid; and type V, kyphosis. After ACAF, the spinal cord was maintained in good curvature with no shifting in all patients. No patient presented with C5 nerve palsy. Mean postoperative Japanese Orthopaedic Association score was significantly better than preoperatively (14.9 points vs. 9.0 points, P < 0.01), with mean improvement rate of 79.8%. CONCLUSIONS: ACAF provides in situ decompression and good curvature to the spinal cord. Good neurologic recovery is obtained with lower incidence of C5 nerve palsy when ACAF is used to treat DKS.