Reconstructive techniques study after anterior decompression of multilevel cervical spondylotic myelopathy

Safety of anterior cervical corpectomy and fusion (ACCF) for the treatment of subaxial cervical spine injuries, a single center comparative matched analysis

INTRODUCTION

Anterior Cervical Discectomy and Fusion (ACDF) and Anterior Cervical Corpectomy and Fusion (ACCF) are both common surgical procedures in the management of pathologies of the subaxial cervical spine. While recent reviews have demonstrated ACCF to provide better decompression results compared to ACDF, the procedure has been associated with increased surgical risks. Nonetheless, the use of ACCF in a traumatic context has been poorly described. The aim of this study was to assess the safety of ACCF as compared to the more commonly performed ACDF.

METHODS

All patients undergoing ACCF or ACDF for subaxial cervical spine injuries spanning over 2 disc-spaces and 3 vertebral-levels, between 2006 and 2018, at the study center, were eligible for inclusion. Patients were matched based on age and preoperative ASIA score.

RESULTS

After matching, 60 patients were included in the matched analysis, where 30 underwent ACDF and ACCF, respectively. Vertebral body injury was significantly more common in the ACCF group (p = 0.002), while traumatic disc rupture was more frequent in the ACDF group (p = 0.032). There were no statistically significant differences in the rates of surgical complications, including implant failure, wound infection, dysphagia, CSF leakage between the groups (p ≥ 0.05). The rates of revision surgeries (p > 0.999), mortality (p = 0.222), and long-term ASIA scores (p = 0.081) were also similar.

CONCLUSION

Results of both unmatched and matched analyses indicate that ACCF has comparable outcomes and no additional risks compared to ACDF. It is thus a safe approach and should be considered for patients with extensive anterior column injury.

Myth or fact: 3D-printed off-the-shelf prosthesis is superior to titanium mesh cage in anterior cervical corpectomy and fusion?

BACKGROUND

To find out if three-dimensional printing (3DP) off-the-shelf (OTS) prosthesis is superior to titanium mesh cages in anterior cervical corpectomy and fusion (ACCF) when treating single-segment degenerative cervical spondylotic myelopathy (DCSM).

METHODS

DCSM patients underwent ACCF from January 2016 to January 2019 in a single center were included. Patients were divided into the 3DP group (28) and the TMC group (23). The hospital stays, operation time, intraoperative blood loss, and the cost of hospitalization were compared. The Japanese Orthopedic Association (JOA) scores and Neck Disability Index (NDI) were recorded pre-operatively, 1 day, 3, 6, 12, and 24 months post-operatively. Radiological data was measured to evaluate fusion, subsidence, and cervical lordosis. Patients were sent with SF-36 to assess their health-related quality of life (HRQoL).

RESULTS

The differences in operative time, intraoperative blood loss, and hospital stay were not statistically significant between groups (p > 0.05). Postoperative dysphagia occurred in 2 cases in the 3DP group and 3 cases in the TMC group, which all relieved one week later. The difference in improvement of JOA and NDI between the two groups was not statistically significant (p > 0.05). No hardware failure was found and bony fusion was achieved in all cases except one in the 3DP group. The difference in cervical lordosis (CL), fused segmental angle (FSA), mean vertebral height (MVH), and subsidence rates between groups at each follow-up time point was not statistically significant and the results of the SF-36 were similar (p > 0.05). The total cost was higher in the 3DP group with its higher graft cost (p < 0.05).

CONCLUSION

In treating single-segment DCSM with ACCF, both 3DP OTS prosthesis and TMC achieved satisfactory outcomes. However, the more costly 3DP OTS prosthesis was not able to reduce subsidence as it claimed.

Interbody Cage Placement Without Plate Supplementation Adjacent to Plated Segments in Multilevel Anterior Cervical Decompression and Fusion

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To evaluate the clinical efficacy and safety of hybrid anterior cervical fixation, focusing on stand-alone segments.

SUMMARY OF BACKGROUND DATA

In the treatment of multilevel cervical stenosis, the number of segments fixed using a plate is limited by placing an interbody cage without plate supplementation at one end of the surgical segment to reduce long plate-related problems. However, the stand-alone segment may experience cage extrusion, subsidence, cervical alignment deterioration, and nonunion.

METHODS

Patients who underwent three-segment or four-segment fixation for cervical degenerative disease and completed one-year follow-up were included in this study. Patients were divided into two groups: a cranial group, with stand-alone segments located at the cranial end adjacent to plated segments, and a caudal group, with stand-alone segments located at the caudal end. Differences in radiographic outcomes between the groups were evaluated. Fusion was defined using dynamic radiographs or computed tomography. To identify factors associated with nonunion in stand-alone segments, multivariable logistic regression analyses were performed. To identify factors associated with cage subsidence, multiple regression analyses were performed.

RESULTS

A total of 116 patients (mean age, 59±11 y; 72% male; mean fixed segments, 3.7±0.5 segments) were included in this study. No case showed cage extrusion or plate dislodgement. In stand-alone segments, the fusion rate was significantly lower in the caudal group than in the cranial group (76% vs. 93%, P =0.019). Change in the cervical sagittal vertical axis was worse in the caudal group than in the cranial group (2.7±12.3 mm vs. -2.7±8.1 mm, P =0.006). One caudal group patient required additional surgery because of nonunion at the stand-alone segment. Multivariable logistic regression indicated factors associated with nonunion included the location of the stand-alone segment (caudal end: OR 4.67, 95% CI, 1.29-16.90), larger pre-disk space range of motion (OR 1.15, 95% CI, 1.04-1.27), and lower preoperative disk space height (OR 0.57, 95% CI, 0.37-0.87). Multiple regression analysis indicated that higher cage height and lower pre-disk space height were associated with cage subsidence.

CONCLUSION

Hybrid anterior cervical fixation with stand-alone interbody cage placement adjacent to plated segments may avoid long plate-related problems. Our results suggest that the cranial end of the construct may be more suitable for the stand-alone segment than the caudal end.

Evaluation of enlarged laminectomy with lateral mass screw fixation in relieving nerve root symptoms and correcting kyphosis for cervical myelopathy and radiculopathy

Purpose

This study aimed to compare the surgical efficacy of enlarged laminectomy with lateral mass screw fixation (EL-LMSF) and anterior cervical decompression and fusion (ACDF) for multilevel cervical myelopathy and radiculopathy (CMR) related to kyphosis.

Methods

75 patients were retrospectively reviewed and divided into ACDF and EL-LMSF group. Clinical results including operative time, blood loss, and postoperative complications were compared. The JOA scoring system was used to evaluate spinal cord function and the VAS score evaluate nerve root pain severity. Cervical alignment a C2-C7 was measured with Cobb method and compared to confirm the reconstruction effect.

Results

Data on 75 patients (M/F: 41:34; EL-LMSF/ACDF:42/33) with the mean age of 57.5 years (range 43-72 year old) were reviewed retrospectively. Discectomy and/or sub-toal corpectomy in ACDF group was performed with a mean of 3.24 levels (range, 3-4). Enlarged laminectomy in EL-LMSF group was performed with a mean of 3.89 enlarged levels (range, 3-5). The procedure of ACDF group showed a shorter operation time (103 ± 22 min vs. 125 ± 37 min, P = 0.000) and less blood loss (78 ± 15 ml vs. 226 ± 31 ml, P = 0.000) compared than that of the EL-LMSF group. Patients treated with EL-LMSF indicated lower VAS for upper extremity (1.3 ± 1.7 vs. 3.3 ± 1.3, P = 0.003) and better curvature corrected (10.7 ± 4.2° vs. 8.5 ± 3.5°, P = 0.013). The difference were of statistical significance. No statistical difference was found after surgery in the JOA score (14.1 ± 1.7 vs. 13.5 ± 2.1, P = 0.222). During the follow-up period, 15.2% of patients in the ACDF group had complications including 2 cases with transient dysphagia, 1 case with C5 palsy, 1 case with axial pain, and 1 case with screw pullout 3 month after surgery. However, only 9.5% of cases in the EL-LMSF group experienced complications, including 3 cases of axial pain and 1 case of epidural hematoma.

Conclusion

The EL-LMSF procedure requires a longer operation time and more blood loss because of the incision of the stenosed foramen. However, the procedure has obvious advantages in relieving nerve root symptoms and correcting cervical curvature with fewer postoperative complications.

Anterior Cervical Corpectomy with Fusion versus Anterior Hybrid Fusion Surgery for Patients with Severe Ossification of the Posterior Longitudinal Ligament Involving Three or More Levels: A Retrospective Comparative Study

Various studies have found a high incidence of early graft dislodgement after multilevel corpectomy. Although a hybrid fusion technique was developed to resolve implant failure, the hybrid and conventional techniques have not been clearly compared in terms of perioperative complications in patients with severe ossification of the posterior longitudinal ligament (OPLL) involving three or more levels. The purpose of this study was to compare clinical and radiologic outcomes between anterior cervical corpectomy with fusion (ACCF) and anterior hybrid fusion for the treatment of multilevel cervical OPLL. We therefore retrospectively reviewed the clinical and radiologic data of 53 consecutive patients who underwent anterior fusion to treat cervical OPLL: 30 underwent ACCF and 23 underwent anterior hybrid fusion. All patients completed 2 years of follow-ups. Implant migration was defined as subsidence > 3 mm. There were no significant differences in demographics or clinical characteristics between the ACCF and hybrid groups. Early implant failure occurred significantly more frequently in the ACCF group (5 cases, 16.7%) compared with the hybrid group (0 cases, 0%). The fusion rate was 80% in the ACCF group and 100% in the hybrid group. Although both procedures can achieve satisfactory neurologic outcomes for multilevel OPLL patients, hybrid fusion likely provides better biomechanical stability than the conventional ACCF technique.

Anterior Cervical Corpectomy and Fusion for Degenerative and Traumatic Spine Disorders, Single-Center Experience of a Case Series of 119 Patients

BACKGROUND

Anterior cervical corpectomy and fusion (ACCF) is a treatment option for several cervical pathologies. Various graft materials such as autografts, titanium mesh cages (TMC), or poly-ether-ether-ketone (PEEK) cages are used. Additional posterior fixation (PF) to provide extra support and improve stability is sometimes performed initially, or later as supplementary treatment.

OBJECTIVE

To describe our retrospective study of 119 consecutive cases of ACCF with synthetic grafts, in 3 cohorts of cervical spondylotic myelopathy (CSM), infectious and neoplastic processes, and trauma, with special focus on need for supplementary PF.

METHODS

A total of 135 adult patients treated with ACCF between January 2005 and January 2018 were identified. Patients lost to follow-up were excluded, and 119 remaining patients were included for retrospective clinical and radiological assessment.

RESULTS

Synthetic grafts were used in 116 (97%) cases. Only 9 (8%) ACCF cases required later supplementary PF, where 7 (78%) cases were multilevel. There was a statistically significant difference in revision rate with PF for single-level compared to multilevel ACCFs (P = .001). Revision rates with PF were 2%, 29%, and 7% in CSM, infectious and neoplastic processes, and trauma cohorts, respectively.

CONCLUSION

The results indicate that ACCF is a safe and effective treatment for degenerative and traumatic cervical spine disorders, with low complication and revision rates. Single-level ACCF can be performed without additional PF. Multilevel ACCF (n > 2) and pathologies affecting bone quality seem to be risk factors for material subsidence and instability. In these cases, additional PF should be considered.

A biomechanical analysis of four anterior cervical techniques to treating multilevel cervical spondylotic myelopathy: a finite element study

BACKGROUND

The decision to treat multilevel cervical spondylotic myelopathy (MCSM) remains controversial. The purpose of this study is to compare the biomechanical characteristics of the intervertebral discs at the adjacent segments and internal fixation, and to provide scientific experimental evidence for surgical treatment of MCSM.

METHODS

An intact C2-C7 cervical spine model was developed and validated. Four additional models were developed from the fusion model, including multilevel anterior cervical discectomy and fusion (mACDF), anterior cervical corpectomy and fusion (ACCF), hybrid decompression and fusion (HDF), and mACDF with cage alone (mACDF-CA). Biomechanical characteristics on the plate and the disc of adjacent levels (C2/3, C6/7) were comparatively analyzed.

RESULTS

Of the four models, stress on the upper (C2/3) adjacent intervertebral disc was the lowest in the mACDF-CA group and highest in the ACCF group. Stress on the intervertebral discs at adjacent segments was higher for the upper C2/3 than the lower C6/7 intervertebral disc. In all models, the mACDF-CA group had the lowest stress on the intervertebral disc, while the ACCF group had the highest stress. In the three surgical models with titanium plate fixation (mACDF, ACCF, and HDF), the ACCF group had the highest stress at the titanium plate-screw interface, while the mACDF group had the lowest stress.

CONCLUSION

Among the four anterior cervical reconstructive techniques for MCSM, mACDF-CA makes little effect on the adjacent disc stress, which might reduce the incidence of adjacent segment degeneration (ASD) after fusion. However, the accompanying risk of the increased incidence of cage subsidence should never be neglected.

Determining the Difference in Clinical and Radiologic Outcomes Between Expandable and Nonexpandable Titanium Cages in Cervical Fusion Procedures: A Systematic Review and Meta-Analysis

BACKGROUND

Expandable cages have been increasingly used in cervical and lumbar reconstructions; however, there is a paucity in the literature on how they compare with traditional nonexpandable cages in the cervical spine. We present a systematic review and meta-analysis, comparing the clinical and radiologic outcomes of expandable versus nonexpandable corpectomy cage use in the cervical spine.

METHODS

A database search identified studies detailing the outcomes of expandable and nonexpandable titanium cage use in the cervical spine. These studies were screened using the PRISMA protocol. Fixed-effects and random-effects models were used with a 95% confidence interval. Two analyses were carried out for each outcome: one including all studies and the other including only studies reporting on exclusively 1-level and 2-level cases.

RESULTS

Forty-one studies were included. The mean change in segmental lordosis was significantly greater in expandable cages (all, 6.72 vs. 3.69°, P < 0.001; 1-level and 2-level, 6.81° vs. 4.31°, P < 0.001). The mean change in cervical lordosis was also significantly greater in expandable cages (all, 5.71° vs. 3.11°, P = 0.027; 1-level and 2-level, 5.71° vs. 2.07°, P = 0.002). No significant difference was found between the complication rates (all, P = 0.43; 1-level and 2-level, P = 0.94); however, the proportion of revisions was significantly greater in expandable cages (all, 0.06 vs. 0.02, P = 0.03; 1-level and 2-level, 0.08 vs. 0.01, P = 0.017).

CONCLUSIONS

The use of expandable cages may carry a modest improvement in radiologic outcomes compared with nonexpandable cages in the cervical spine; however, they may also lead to a higher rate of revisions based on our analyses.

Hybrid decompression and reconstruction technique for cervical spondylotic myelopathy: case series and review of the literature

The primary treatment of choice for patients with cervical spondylotic myelopathy (CSM) is surgical decompression. The benefit of operative intervention has been well established but, the surgeons' decision of operative approach remains nuanced based on patient-specific variables and surgeon preference. Decompression can involve a cervical corpectomy or a discectomy. A hybrid construct is when both a cervical corpectomy and a discectomy are done in the same patient. The purpose of this study was to review the evidence on the clinical and biomechanical outcomes of hybrid decompression and reconstruction techniques in patients with multilevel CSM. A retrospective study was performed on consecutive patients who received hybrid anterior decompression and reconstruction at Rush University between 2013-2018. Preoperative clinical and radiographic variables were analyzed to characterize specific factors leading to the decision of the surgical approach. In addition, we performed a systematic review and meta-analysis to assess superiority in terms of operative time, blood loss, cervical lordosis, patient-reported outcomes (PRO), fusion rates, and complications. Hybrid surgery (HS) was utilized in cases where multilevel CSM was present in conjunction with stenosis posterior to the vertebral body or acute kyphotic deformity. Our meta-analysis highlighted comparable PRO, complications, and rate of success fusion between 3-level anterior cervical discectomy and fusion (ACDF) and hybrid technique. Furthermore, hybrid fusion led to increased postoperative cervical lordosis, higher fusion rate, lower total complication rate, lower implant failure/mesh subsidence rate, and lower blood loss than 2-level corpectomy. The cervical hybrid technique that combines cervical corpectomy and discectomy represents a balanced option with the benefits of two commonly utilized cervical spine procedures in patients with multilevel CSM. The literature on hybrid technique suggests in cases where multilevel ACDF is not feasible, combining discectomy and corpectomy is superior to two-level corpectomy with lower complication rates, improved clinical outcome, spinal alignment correction, and stronger biomechanical properties.

Prevalence and risk factors of axial neck pain in patients undergoing multilevel anterior cervical decompression with fusion surgery

Objectives

The aim of this study was to explore the prevalence and risk factors for axial neck pain in patients undergoing multilevel anterior cervical decompression with fusion surgery.

Methods

In this study, 88 patients, who underwent multilevel anterior cervical decompression with fusion surgery from January 2012 to January 2017, were retrospectively reviewed. Based on the postoperative axial neck pain, the patients were classified into two groups: axial pain group and no axial pain group. The patients were followed up 3 weeks, 3 months, and 1 year after cervical anterior surgery for the early- and long-term clinical evaluation. The possible effect factors included demographic variables (age, sex, BMI, smoking, drinking, heart disease, hypertension, diabetes, preoperative kyphosis, preoperative axial neck pain, preoperative JOA scores, and ODI) and surgery-related variables (surgical option, vertebral lesions, spinal canal stenosis rate, superior fusion segment, presence of intramedullary high signal intensity).

Results

The prevalence of axial neck pain was 27.3% (24 cases of 88). Our results showed that preoperative axial neck pain (62% vs 23%, P < 0.001) and preoperative kyphosis (42% vs 21.9%, P < 0.001) were risk factors for axial pain after multilevel anterior cervical surgery. Additionally, for patients with preoperative cervical kyphosis, compared to no axial pain group, the axial neck group was significantly more likely to exist a higher preoperative angle of C2–7 (13.31 ± 2.33 vs 7.33 ± 2.56, P < 0.001) and a higher correction range for kyphosis (20.24 ± 4.12 vs 12.34 ± 3.12, P < 0.001). However, for all the patients with postoperative axial symptoms, the improvement rate of axial pain was significantly higher for patients without cervical kyphosis at the early-term follow-up (3 weeks) (P = 0.032), no significant differences were found at the medium-term (P = 0.554) and long-term follow-up (P = 0.902), and improvements of clinical symptom have no obvious difference at the last follow-up.

Conclusions

Overall, preoperative axial neck pain and kyphosis could predict axial neck pain for patients undergoing multilevel anterior cervical decompression with fusion surgery, and recovery of cervical kyphosis may contribute to the long-term recovery of neural function, but may also suffer from risk of short-term axial pain, which could be reduced through moderate cervical curvature recovery.

Two-level cervical corpectomy-long-term follow-up reveals the high rate of material failure in patients, who received an anterior approach only

In contrast to a one-level cervical corpectomy, a multilevel corpectomy without posterior fusion is accompanied by a high material failure rate. So far, the adequate surgical technique for patients, who receive a two-level corpectomy, remains to be elucidated. The aim of this study was to determine the long-term clinical outcome of patients with cervical myelopathy, who underwent a two-level corpectomy. Outcome parameters of 21 patients, who received a two-level cervical corpectomy, were retrospectively analyzed concerning reoperations and outcome scores (VAS, Neck Disability Index (NDI), Nurick scale, modified Japanese Orthopaedic Association score (mJOAS), Short Form 36-item Health Survey Questionnaire (SF-36)). The failure rate was determined using postoperative radiographs. The choice over the surgical procedures was exercised by every surgeon individually. Therefore, a distinction between two groups was possible: (1) anterior group (ANT group) with a two-level corpectomy and a cervical plate, (2) anterior/posterior group (A/P group) with two-level corpectomy, cervical plate, and additional posterior fusion. Both groups benefitted from surgery concerning pain, disability, and myelopathy. While all patients of the A/P group showed no postoperative instability, one third of the patients of the ANT group exhibited instability and clinical deterioration. Thus, a revision surgery with secondary posterior fusion was needed. Furthermore, the ANT group had worse myelopathy scores (mJOAS_{ANT group} = 13.5 ± 2.5, mJOAS_{A/P group} = 15.7 ± 2.2). Patients with myelopathy, who receive a two-level cervical corpectomy, benefitted from surgical decompression. However, patients with a sole anterior approach demonstrated a very high rate of instability (33%) and clinical deterioration in a long-term follow-up. Therefore, we recommend to routinely perform an additional posterior fusion after two-level cervical corpectomy.

Anterior decompression and plate fixation in treatment of cervical myelopathy: A multicentric retrospective review

OBJECTIVES

The aim of this study was to evaluate the results on anterior decompression and fusion with titanium mesh or expanding cage and plate fixation in patients with cervical myelopathy.

METHODS

We conducted a retrospective multicentric review of 114 patients, 75 males and 39 females, with cervical myelopathy who underwent surgical treatment between July 2009 to December 2011. All surgeries were performed via a ventral approach. Based on the type of surgery the patients received, they were divided into 3 groups: group 1 consisted of 49 patients who received multilevel corpectomies and fusion with strut iliac bone graft and plates; group 2 consisted of 26 patients who received multilevel corpectomies and fusion with titanium expanding cage and plating; group 3 consisted of 39 patients who received multilevel corpectomies and fusion using titanium mesh with autologous bone graft and anterior plating.

RESULTS

Decompression of the cervical spinal cord and grafting with plate fixation via a ventral approach demonstrated a high rate of improvement in neurological function with minimal complications. Fusion was documented radiologically in all cases. Eighty-three patients experienced a partial improvement and 41 had a complete recovery according to Nurick's myelopathy grading. Sixty-two patients were ranked as excellent, 48 as good, 4 as fair; unsatisfactory outcome was related to donor site complications.

CONCLUSION

Spinal decompression and fusion with titanium cages and plates appears to be a safe and effective alternative in patients with cervical spinal myelopathy.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Ossification of the Posterior Longitudinal Ligament in Cervical Spine: Prevalence, Management, and Prognosis

Ossification of the posterior longitudinal ligament (OPLL) in the cervical spine and related neurological complications are not uncommon in East Asian countries. The estimated prevalence of cervical OPLL-related hospitalization is 7.7 per 100,000 person-years in Taiwan, and higher incidence rates have been observed in elderly and male patients. Although cervical OPLL is frequently insidious, it can eventually cause myelopathy and predispose patients to spinal cord injury (SCI). There are multiple options for managing cervical OPLL, ranging from observation to many kinds of surgical procedures, including posterior laminoplasty, laminectomy with or without fusion, anterior corpectomy with or without instrumentation, and circumferential decompression and fusion. None of these surgical approaches is free of complications. However, to date, there is still a lack of consensus regarding the choice of the surgical approach and the timing of surgical intervention. Cervical SCI and related neurological disabilities are more likely to occur in OPLL patients, who should therefore be cautioned regarding the possibility of a subsequent SCI if treated without surgery. This article aimed to review the prevalence, management strategies, and prognosis of cervical OPLL.

A Comparison of Multilevel Anterior Cervical Discectomy and Corpectomy in Patients With 4-level Cervical Spondylotic Myelopathy: a Minimum 2-year Follow-up Study: Multilevel Anterior Cervical Discectomy

STUDY DESIGN

Retrospective clinical series.

OBJECTIVES

To compare perioperative parameters, clinical outcomes, radiographic parameters, and complication rates of segmental anterior cervical corpectomy and fusion (sACCF) plus preservation of middle vertebrae with those of multilevel anterior cervical discectomy and fusion (mACDF) in 70 patients with 4-level cervical spondylotic myelopathy (CSM).

METHODS

Between July 2006 and May 2011, 70 consecutive patients [49 males and 21 females; mean age 56.8 y (range, 38-72 years)] with 4-level CSM were enrolled in this study and divided into sACCF (n=39) group and mACDF (n=31) group. The study compared perioperative parameters, complication rates, clinical parameters, and radiologic parameters.

RESULTS

No significant differences between the groups were found in demographic, baseline disease characteristics, operation time, hospital stay, and follow-up time. Significant improvements of clinical outcome were seen from preoperative to postoperative in both groups. Satisfaction was rated as excellent or good by 79.5% of the sACCF group and 80.6% of the mACDF group, which was not a significant difference. Mean postoperative cervical lordosis was significantly greater in the mACDF group than in the sACCF group. Blood loss was significantly greater in the sACCF group than in the mACDF group and instrumentation-related and/or graft-related complication rate significantly lower for the mACDF group. Both sACCF and mACDF groups achieved solid fusion rates (87.1% and 90.3%, respectively).

CONCLUSIONS

Both mACDF and sACCF provide satisfactory clinical outcomes and fusion rates for 4-level CSM. However, mACDF is associated with better radiologic parameter, less blood loss, and lower instrumentation-related and/or graft-related complication rate.

Comparison of Three Reconstructive Techniques in the Surgical Management of Patients With Four-Level Cervical Spondylotic Myelopathy

STUDY DESIGN

Retrospective clinical series.

OBJECTIVE

To compare perioperative parameters, clinical outcomes, radiographic parameters, and complication rates of three reconstructive techniques after the anterior decompression of four-level cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

At present, the decision to treat multilevel CSM, especially four-level CSM, remains controversial. No one compares multilevel anterior cervical discectomy and fusion (mACDF), segmental anterior cervical corpectomy and fusion (sACCF) to multilevel anterior cervical discectomy and fusion with cage alone (mACDF-CA) in four-level constructs.

METHODS

Between July 2006 and February 2014, 97 consecutive patients with four-level CSM were enrolled in this study and divided into sACCF (n = 39) group, mACDF (n = 31) group, and mACDF-CA (n = 27) group. The study compared perioperative parameters, complication rates, clinical and radiologic parameters of three reconstructive techniques after the anterior decompression of four-level CSM.

RESULTS

The mACDF-CA group had the least bleeding and cost of index surgery compared with the sACCF group having the most bleeding and cost. Although significant pain relief and functional activity improvement have been achieved in the three groups at the final follow-up, there was no significant difference in the Japanese Orthopedic Association, SF-36 and NDI scores among the three groups (P >0.05). The mACDF group maintained the best cervical lordosis at the final follow-up, compared with the sACCF group maintained the worst cervical lordosis. Solid fusion was achieved in 87.1% of subjects in sACCF group, 90.3% in mACDF, and in 88.9% in mACDF-CA. The mACDF-CA group had a higher rate of subsidence and lower rate of dysphagia than other two groups.

CONCLUSION

mACDF-CA can be considered an effective and safe alternative procedure in the treatment of the four-level CSM.

LEVEL OF EVIDENCE

4.

Anterior decompression and hybrid reconstruction with titanium mesh cage plus plate and self-locking stand-alone cage for the treatment of three-level cervical spondylotic myelopathy

It has been reported that anterior cervical decompression has good clinical outcomes for the treatment of adjacent three-level cervical spondylotic myelopathy (CSM). However, the application of a long plate in the anterior cervical spine poses substantial risks of soft tissue damage. In this retrospective study, we aimed to analyze the clinical and radiological results of the hybrid construction with titanium mesh cage (TMC) plus plate and self-locking stand-alone cage for treatment of adjacent three-level CSM. A total of 28 consecutive patients with adjacent three-level CSM were treated by anterior decompression and hybrid reconstruction with TMC plus plate and self-locking stand-alone cage. Clinical outcomes, complications, fusion rate and time, cage subsidence and spinal curvature were assessed. The mean follow-up period was 22.8months. The average operative time was 103±18.5min, and the average blood loss was 115±13.3mL. The JOA score and degree of spinal curvature were significantly increased at the final follow-up compared with preoperatively (P<0.05). Twenty-seven cases finally achieved a solid fusion, and the average time to achieve a solid fusion was 6.2months. Postoperative complications included one case of cerebrospinal fluid leakage (3.57%), one case of temporary sore throat (3.57%) and two cases of TMC subsidence (7.1%). No dysphagia and hoarseness were observed. Anterior decompression and hybrid reconstruction with TMC plus plate and self-locking stand-alone cage could be used safely and effectively for the treatment of adjacent three-level CSM. It could effectively restore cervical lordosis, reduce the complications related to long plate fixation, and lead to satisfactory outcomes.

Anterior cervical discectomy and fusion versus anterior cervical corpectomy and fusion in multilevel cervical spondylotic myelopathy: A meta-analysis

BACKGROUND

Both anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) are used to treat multilevel cervical spondylotic myelopathy (mCSM); however, which one is better treatment for mCSM remains considerable controversy. A meta-analysis was performed to compare clinical outcomes, radiographic outcomes, and surgical outcomes between ACDF and ACCF in treatment for mCSM.

METHODS

An extensive search of literature was performed in Pubmed/MEDLINE, Embase, the Cochrane library, CNKI, and WANFANG databases on ACDF versus ACCF treatment for mCSM from January 2011 to August 2016. The following variables were extracted: length of hospital stay, blood loss, operation time, Japanese Orthopedic Association (JOA) scores, Neck Disability Index (NDI) score, fusion rate, Cobb angles of C2 to C7, dysphagia, hoarseness, C5 palsy, infection, cerebral fluid leakage, donor site pain, epidural hematoma, graft subsidence, graft dislodgment, pseudoarthrosis, and total complications. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

RESULTS

A total of 8 studies containing 878 patients were included in our study. The results showed that ACDF is better than ACCF in the angle of C2 to C7 at the final follow-up (P < 0.00001, standardized mean difference = 4.76 [3.48, 6.03]; heterogeneity: P = 0.17, I = 43%), C5 plasy (P = 0.02, odds ratio [OR] 0.42, 95% confidence interval [CI] 0.21, 0.86; heterogeneity: P = 0.52, I = 0%), blood loss (P < 0.00001, standardized mean difference = -53.12, 95% CI -64.61, -41.64; heterogeneity: P = 0.29, I = 20%), fusion rate (P = 0.04, OR 2.54, 95% CI 1.05, 6.11; heterogeneity: P = 0.29, I = 20%), graft subsidence (P = 0.004, OR 0.11, 95% CI 0.02, 0.48; heterogeneity: P = 0.94, I = 0%), and total complications (P = 0.0009, OR 0.56, 95% CI 0.40, 0.79; heterogeneity: P = 0.29, I = 18%).However, there are no significant differences in length of hospital stay, operation time, JOA scores, NDI scores, preoperative angle of C2 to C7, dysphagia, hoarseness, infection, cerebral fluid leakage, donor site pain, epidural hematoma, graft dislodgment, and pseudoarthrosis (all P > 0.05).

CONCLUSIONS

Based on our meta-analysis, our results suggest that both ACDF and ACCF are good plans in clinical outcomes; however, ACDF is a better choice in radiographic outcomes and total complications for the treatment of multilevel CSM.

The application of a new type of titanium mesh cage in hybrid anterior decompression and fusion technique for the treatment of continuously three-level cervical spondylotic myelopathy

PURPOSE

To evaluate the efficacy and safety of a new type of titanium mesh cage (NTMC) in hybrid anterior decompression and fusion method (HDF) in treating continuously three-level cervical spondylotic myelopathy (TCSM).

METHODS

Ninety-four cases who had TCSM and accepted the HDF from Jan 2007 to Jan 2010 were included. Clinical and radiological outcomes were compared between cases who had the NTMC (Group A, n = 45) and traditional titanium mesh cage (TTMC, Group B, n = 49) after corpectomies. Each case accepted one polyetheretherketone cage (PEEK) after discectomy.

RESULTS

Mean follow-up were 74.4 and 77.3 months in Group A and B, respectively (p > 0.05). Differences in cervical lordosis (CL), segmental lordosis (SL), anterior segmental height (ASH) and posterior segmental height (PSH) between two groups were not significant preoperatively, 3-days postoperatively or at final visit. However, losses of the CL, SL, ASH and PSH were all significantly larger in Group B at the final visit, so did incidences of segmental subsidence and severe subsidence. Difference in preoperative Japanese Orthopedic Association (JOA), visual analog scale (VAS), neck disability index (NDI) or SF-36 between two groups was not significant. At the final visit, fusion rate, JOA, and SF-36 were all comparable between two groups, but the VAS and NDI were both significantly greater in Group B.

CONCLUSIONS

For cases with TCSM, HDF with the NTMC and TTMC can provide comparable radiological and clinical improvements. But application of the NTMC in HDF is of advantages in decreasing the subsidence incidence, losses of lordosis correction, VAS and NDI.

Hybrid Decompression and Fixation Technique Versus Plated 3-Vertebra Corpectomy for 4-Segment Cervical Myelopathy: Analysis of 81 Cases With a Minimum 2-Year Follow-Up

STUDY DESIGN

A retrospective comparative study.

OBJECTIVE

The purpose of this study was to compare the stability and outcomes of a hybrid technique with those of a 3-vertebra corpectomy in the management of 4-segment cervical myelopathy.

SUMMARY OF BACKGROUND DATA

Patients with primarily ventral disease and loss of cervical lordosis are considered good candidates for anterior surgery. Cervical corpectomy is commonly performed in patients with multilevel cervical myelopathy. Corpectomies including >3 vertebraes entail an extremely high risk of reconstruction failure. To avoid the need to perform a 3-vertebra corpectomy, we use a hybrid decompression and fixation technique. This hybrid technique is a technique to obtain optimum decompression and fixation in patients with multilevel cervical myelopathy.

METHODS

A total of 81 patients with multilevel cervical myelopathy who underwent 4-segment cervical fixation with a minimum 2-year follow-up were included.

RESULTS

The hybrid technique involved combining a plated 2-vertebra corpectomy and single-level discectomy with stand-alone cage fixation. This technique was performed in 39 patients, and the plated 3-vertebra corpectomy was performed in 42 patients. Nine patients (21%) who underwent the plated 3-vertebra corpectomy were treated with halo immobilization, but no patient in the hybrid group required this treatment (P=0.002). There were fewer instances of reconstruction failure in the hybrid group than in the 3-vertebra corpectomy group (0% vs. 10%, respectively; P=0.048) and fewer instances of C5 palsy (3% vs. 17%, respectively; P <0.0001). The incidence of postoperative C5 palsy was 25% for C3-C5 corpectomy, 19% for C4-C6 corpectomy, and 11% for C4-C5 corpectomy+C6-C7 discectomy.

CONCLUSIONS

The hybrid technique has the following advantages over 3-vertebra corpectomy for 4-segment cervical fixation: a shorter graft bone and plate are required; the fixed segment has greater initial stability; postoperative external immobilization is simplified; and the risk of reconstruction failure and postoperative C5 palsy is reduced markedly.

Expansion Open-door Laminoplasty With Foraminotomy Versus Anterior Cervical Discectomy and Fusion for Coexisting Multilevel Cervical Myelopathy and Unilateral Radiculopathy

STUDY DESIGN

This was a clinical prospective study.

OBJECTIVE

To assess whether clinical and radiologic outcomes differ between expansion open-door laminoplasty with foraminotomy (EOLF) and anterior cervical discectomy and fusion (ACDF) in the treatment of coexisting multilevel cervical myelopathy and unilateral radiculopathy (CMUR).

SUMMARY OF BACKGROUND DATA

No reports to date have compared clinical outcomes between anterior and posterior decompression for CMUR.

MATERIALS AND METHODS

We prospectively performed ACDF (n=59) in 2004, 2006, and 2008 and EOLF (n=62) in 2005, 2007, and 2009. The Japanese Orthopedic Association (JOA) score and recovery rate were evaluated. For radiographic evaluation, the lordotic angle and range of motion at C2-C7 were investigated.

RESULTS

Only 110 patients could be followed for >3 years (EOLF/ACDF: 56/54; follow-up rate, 90.9%). Demographics were similar between the 2 groups. Compared with ACDF, in EOLF group there were shorter operating time (144 vs. 178 min), less bleeding (175 vs. 192 mL), and fewer complications (P<0.05). Results of JOA score and recovery rate, at 3-year postoperative follow-up, showed no statistical difference for the 2 groups. Cervical lordosis of ACDF increased from 13.7 to 16.2 degrees, whereas that of EOLF group decreased from 14.6 to 13.3 degrees (P<0.05). The percentage of range of motion declined in the 2 groups (ACDF/EOLF), 57.4% versus 74.7% (P<0.05).

CONCLUSIONS

The 2 surgical procedures have similar clinical effects in treating multisegmental CMUR. However, the EOLF group demonstrated shorter operative time, less blood loss, and fewer complications; therefore, it proved to be a more effective and safer method.

Hybrid Decompression Technique Versus Anterior Cervical Corpectomy and Fusion for Treating Multilevel Cervical Spondylotic Myelopathy: Which One Is Better?

BACKGROUND

The hybrid decompression technique (corpectomy combined with discectomy) and anterior cervical corpectomy with fusion (ACCF) both provide good neurological recovery and disease stabilization for the treatment of multilevel cervical spondylotic myelopathy (CSM). However, no single study has been large enough to determine definitively which one is superior for this condition.

OBJECTIVE

A meta-analysis was conducted to compare the clinical efficacy and safety of the hybrid decompression technique versus ACCF for the treatment of multilevel CSM.

METHODS

Electronic databases such as PubMed, MEDLINE, EMBASE, Google Scholar, and the Cochrane Library were selected to search for potentially relevant trials up to April 2015 that compared the outcomes of the hybrid technique with ACCF for the treatment of multilevel CSM. Data extraction and quality assessment were performed according to Cochrane Collaboration guidelines. The outcome assessments were duration of surgery, blood loss, Cobb angle of C2-C7, segment angle, fusion rate, Japanese Orthopedics Association score, Neck Disability Index, and complications. The results were expressed as the odds ratio (OR) for dichotomous outcomes and the mean difference (MD) for continuous outcomes with a 95% confidence interval (CI).

RESULTS

Five controlled clinical trials published between 2009 and 2013, involving 356 patients (hybrid, 196; ACCF, 160) with 3- or 4-level CSM were retrieved in this study. Overall, there were significant differences between the 2 treatment groups for blood loss (MD = -38.69, 95% CI = -54.62 to -22.76, P < 0.01), fusion rate (OR = 2.56, 95% CI = 1.11 to 5.93, P = 0.03), and complications (OR = 0.25, 95% CI = 0.15 to 0.43, P < 0.01). However, no significant differences were found for duration of surgery (MD = -4.50, 95% CI = -22.902 to 13.91, P = 0.63), Cobb angle of C2-C7 after surgery (MD = 3.32, 95% CI = -3.72 to 10.37, P = 0.35), segment angle after surgery (MD = 2.87, 95% CI = -2.47 to 8.21, P = 0.29), Japanese Orthopedics Association score (MD = -0.07, 95% CI = -0.36 to 0.22, P = 0.62), or Neck Disability Index (MD = -0.86, 95% CI = -3.26 to 1.54, P = 0.48).

CONCLUSION

Based on this meta-analysis, both the hybrid technique and ACCF can achieve good results for CSM. However, the hybrid technique is associated with significantly less blood loss, complications, and a higher fusion rate than ACCF.

Anterior approaches for cervical spondylotic myelopathy: which? When? How?

Cervical spondylotic myelopathy is a degenerative disorder with an unfavorable natural history. Surgical treatment options have evolved substantially over time, with both anterior and posterior methods proving successful for certain patients with specific characteristics. Anterior decompression of the spinal canal plus fusion techniques for stabilization has several advantages and some disadvantages when compared to posterior options. Understanding the pros and cons of the approaches and techniques is critical for the surgeon to select the best operative treatment strategy for any given patient to achieve the best outcome. Multiple decision-making factors are involved, such as sagittal alignment, number of levels, shape of the pathoanatomy, age and comorbidities, instability, and pre-operative pain levels. Any or all of these factors may be relevant for a given patient, and to varying degrees of importance. Choice of operative approach will therefore be dependent on patient presentation, risks of that approach for a given patient, and to some degree surgeon experience.

A cadaveric analysis of cervical fixation: the effect of intermediate fixation points and dynamization in multilevel cervical fusions

OBJECT

The authors conducted a study to compare biomechanical effects on the cervical spine of bridging fixation and intermediate fixation techniques, in both fixed and dynamic modes.

METHODS

A biaxial, servohydraulic machine biomechanically tested 23 human cervical spines for stiffness and strain in compression, extension, flexion, and lateral bending through 3 specimen states: 1) intact, 2) defect (corpectomy and discectomy), and 3) grafting with plate application in 1 of 4 constructs: C3-7 dynamized long strut (DLS), C3-7 fixed long strut (FLS), C3-5-7 dynamized multisegment (DMS), and C3-5-7 fixed multisegment (FMS).

RESULTS

Compared with FMS, FLS had significantly greater strain in extension (at C-3 and at the rostral and caudal parts of the graft) and in lateral bending (at C-3 and at the caudal part of the graft). Fixed (FLS and FMS) constructs had greater flexion stiffness than did dynamized (DLS and DMS) constructs and showed a trend toward greater lateral bending stiffness. Instrumentation revealed greater extension strain with the long fixed (FLS and DLS) constructs than with the multifixed (FMS and FMS) constructs at the rostral and caudal parts of the graft but no significant differences between the dynamized (DLS and DMS) and fixed (FLS and FMS) constructs.

CONCLUSIONS

Multisegmental fixation provided greater stabilizing forces than did bridging constructs for both dynamized and fixed plates. Use of multisegmental fixation can potentially decrease strain at the screw-plate interface and reduce the rate of hardware failure.

Comparison of anterior surgical options for the treatment of multilevel cervical spondylotic myelopathy: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

The primary objectives of this review were to compare the effectiveness and safety of various anterior cervical decompressive and reconstructive procedures for diffuse or multifocal cervical spondylotic myelopathy (CSM). An additional objective was to describe the most common ancillary stabilization techniques used with the different anterior decompressive procedures.

SUMMARY OF BACKGROUND DATA

Surgical management of CSM provides for neurological recovery and disease stabilization in a cost-effective way. Although both retrospective and prospective data support management of CSM by anterior cervical decompression and fusion, the choice decision between various anterior surgical options remains unclear.

METHODS

We conducted a systematic search in MEDLINE and the Cochrane Collaboration Library for human studies in the English-language literature published through September 2012. We included studies comparing multiple discectomies with single or multiple corpectomy, multiple discectomies with discectomy-corpectomy hybrid, and multiple corpectomies with discectomy-corpectomy hybrid, comparing effectiveness and safety outcomes of each procedure, and defining the ancillary stabilization techniques used. Exclusion criteria included patients with degenerative disc disease or degenerative joint disease without CSM, single-level CSM, ossified posterior longitudinal ligament (OPLL), spinal tumor, concomitant infection, and ankylozing spondylitis. Case series, case reports, data not reported separately for each comparison group, or studies that consisted of an N less than 10 for either comparison group were excluded. The evidence strength was rated using the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) criteria.

RESULTS

Of the 49 citations identified from our search, 10 studies were initially found suitable for inclusion. Patients undergoing any of the 3 procedures generally experienced improvements in clinical outcomes (neck disability index, Japanese Orthopaedic Association score, and Visual Analogue Scale score for pain) as well as overall sagittal alignment, with minimal perioperative morbidity. There is moderate evidence supporting selection of multiple discectomies compared with corpectomy or discectomy-corpectomy hybrid procedures with regard to superior clinical outcomes and postoperative sagittal alignment. Furthermore, if more extensive operation is needed, there is evidence to support the selection of discectomy-corpectomy hybrid procedures compared with multiple corpectomies if it is technically feasible to accomplish the requisite decompression. The multiple discectomies approach also may have a lower incidence of C5 palsy than corpectomy or discectomy-corpectomy hybrid approaches.

CONCLUSION

All 3 operative approaches are effective strategies for the anterior surgical management of CSM. When the patient pathoanatomy permits, selection of multiple discectomies is favored compared with corpectomy or discectomy-corpectomy hybrid approaches. EVIDENCE-BASED CLINICAL RECOMMENDATIONS:

RECOMMENDATION 1

When pathoanatomically appropriate with minimal retrovertebral disease, we recommend the selection of multiple discectomy over corpectomy or discectomy-corpectomy hybrid procedures.

OVERALL STRENGTH OF EVIDENCE

Low.

STRENGTH OF RECOMMENDATION

Strong.

RECOMMENDATION 2

When retrovertebral disease is significant, we recommend, when possible, that discectomy-corpectomy hybrid procedures be performed instead of multiple corpectomies.

OVERALL STRENGTH OF EVIDENCE

Moderate.

STRENGTH OF RECOMMENDATION

Strong. SUMMARY STATEMENTS: There is no evidence to guide choice of ancillary external immobilization techniques following multilevel anterior decompression and fusion procedures for CSM.

Comparison of 3 reconstructive techniques in the surgical management of multilevel cervical spondylotic myelopathy

STUDY DESIGN

A retrospective comparative study was performed in patients with 3-level cervical spondylotic myelopathy (CSM).

OBJECTIVE

To compare the clinical outcomes, radiological parameters, and complication incidence of 3 reconstructive techniques after the anterior decompression of multilevel CSM.

SUMMARY OF BACKGROUND DATA

There has been growing interest in combination of anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) for the treatment of multilevel CSM in recent years. However, the clinical efficacy and radiological outcomes of the hybrid decompression and fusion (HDF) have rarely been investigated.

METHODS

A total of 180 consecutive patients with 3-level CSM undergoing the anterior decompression and fusion procedures from January 2003 to July 2010 were retrospectively investigated. According to various reconstructive techniques, the patients were divided into 3 groups: HDF, ACDF, and ACCF groups. The clinical effects and improvements of cervical and segmental lordosis in each group were assessed. In addition, the fusion rate, postoperative complications, and radiographical adjacent-level changes regarding each group were also evaluated.

RESULTS

No statistical differences in clinical effects, restoration of cervical lordosis, and incidences of postoperative complications were found between the HDF and ACDF groups (P > 0.05). The ACCF group has achieved clinical effects similar to the ACDF or HDF group (P > 0.05), but it had more bleeding, lower fusion rate, and higher incidences of postoperative complications compared with the ACDF or HDF group (P < 0.05). The improvements of the cervical and segmental lordosis in the ACCF group were significantly less than the ACDF or HDF group (P < 0.05). There was no significant difference in radiographical adjacent-level changes among the 3 groups (P > 0.05).

CONCLUSION

The HDF can be considered an effective and safe alternative procedure compared with ACDF in the treatment of the multilevel CSM, and ACCF should be the last option.

Anterior corpectomy versus posterior laminoplasty: is the risk of postoperative C-5 palsy different?

OBJECT

Both anterior cervical corpectomy and fusion (ACCF) and laminoplasty are effective treatments for selected cases of cervical stenosis. Postoperative C-5 palsies may occur with either anterior or posterior decompressive procedures; however, a direct comparison of C-5 palsy rates between the 2 approaches is not present in the literature. The authors sought to compare the C-5 palsy rate of ACCF versus laminoplasty.

METHODS

The authors conducted a retrospective review of 31 ACCF (at C-4 or C-5) and 31 instrumented laminoplasty cases performed to treat cervical stenosis. The demographics of the groups were similar except for age (ACCF group mean age 53 years vs laminoplasty group mean age 62 years, p = 0.002). The mean number of levels treated was greater in the laminoplasty cohort (3.87 levels) than in the ACCF cohort (2.74 levels, p < 0.001). The mean preoperative Nurick grade of the laminoplasty cohort (2.61) was higher than the mean preoperative Nurick grade of the ACCF cohort (1.10, p < 0.001).

RESULTS

The overall clinical follow-up rate was 100%. The mean overall clinical follow-up was 15 months. There were no significant differences in the estimated blood loss or length of stay between the 2 groups (p > 0.05). There was no statistical difference between the complication or reoperation rates between the 2 groups (p = 0.184 and p = 0.238). There were 2 C-5 nerve root pareses in each group. Three of the 4 patients recovered full deltoid function, and the fourth patient recovered nearly full deltoid function at final follow-up. There was no statistical difference in the rate of deltoid paresis (6.5%) between the 2 groups (p = 1).

CONCLUSIONS

Both ACCF and laminoplasty are effective treatments for patients with cervical stenosis. The authors found no difference in the rate of deltoid paresis between ACCF and laminoplasty to treat cervical stenosis.

Comparative analysis of complications of different reconstructive techniques following anterior decompression for multilevel cervical spondylotic myelopathy

PURPOSE

Anterior approach was extensively used in surgical treatment of multilevel cervical spondylotic myelopathy. Following anterior decompression, many different reconstructive techniques (multilevel ACDF, hybrid construct and long corpectomy) all had satisfied outcomes. However, there are few studies focusing on the comparison of these three reconstructed techniques. The aim of this retrospective study was to analyze the complications of these three different methods.

METHODS

This study retrospectively reviewed the complications in 286 consecutive patients with multilevel CSM who underwent anterior cervical surgery from 2005 to 2010. This case series had 166 men and 120 women whose mean age at surgery was 53.8 years (range from 33 to 74 years). Radiographic evaluation was taken the day after surgery, and the flexion-extension X-rays were added 3, 12 and 24 months postoperatively to evaluate the fusion condition. Preoperative versus postoperative neurologic function and clinical outcome were evaluated using scoring systems such as the Japanese Orthopedic Association (JOA score), Neck Disability Index (NDI score) and 36-Item Short-Form Health Survey (SF-36 score).

RESULTS

There were no significant differences in JOA scores, NDI scores and SF-36 scores of the pairwise comparison among the three groups. The complications in our series included graft migration, collapse or displacement, hoarseness, dysphagia, C5 palsy, cerebral fluid leakage and wound infection. Sixty-one patients developed complications after surgery and the rate of complication was 21.33 %. Patients in the long corpectomy group had the highest rate of complications; the other two groups had a much lower rate of complications by the latest follow-up. The patients in the multilevel ACDF group had the highest fusion rate by the last follow-up. Patients who had C2-3 and C3-4 segments involved had a higher rate of postoperative hoarseness and dysphagia.

CONCLUSIONS

Most of the complications of the three reconstructive techniques subsided gradually after conservative treatment; none of them needed revision surgery. The multilevel ACDF approach has the lowest rate of non-union, but a slightly higher morbidity of the laryngeal nerve-related complication if proximal segments were involved. The long corpectomy approach should be selected prudently because of the high rate of complication.

Biomechanical comparison of anterior cervical spine instrumentation techniques with and without supplemental posterior fusion after different corpectomy and discectomy combinations: Laboratory investigation

OBJECT

The objective of this study was to compare the stiffness and range of motion (ROM) of 4 cervical spine constructs and the intact condition. The 4 constructs consisted of 3-level anterior cervical discectomy with anterior plating, 1-level discectomy and 1-level corpectomy with anterior plating, 2-level corpectomy with anterior plating, and 2-level corpectomy with anterior plating and posterior fixation.

METHODS

Eight human cadaveric fresh-frozen cervical spines from C2-T2 were used. Three-dimensional motion analysis with an optical tracking device was used to determine motion following various reconstruction methods. The specimens were tested in the following conditions: 1) intact; 2) segmental construct with discectomies at C4-5, C5-6, and C6-7, with polyetheretherketone (PEEK) interbody cage and anterior plate; 3) segmental construct with discectomy at C6-7 and corpectomy of C-5, with PEEK interbody graft at the discectomy level and a titanium cage at the corpectomy level; 4) corpectomy at C-5 and C-6, with titanium cage and an anterior cervical plate; and 5) corpectomy at C-5 and C-6, with titanium cage and an anterior cervical plate, and posterior lateral mass screw-rod system from C-4 to C-7. All specimens underwent a pure moment application of 2 Nm with regards to flexion-extension, lateral bending, and axial rotation.

RESULTS

In all tested motions the statistical comparison was significant between the intact condition and the 2-level corpectomy with anterior plating and posterior fixation construct. All other statistical comparisons between the instrumented constructs were not statistically significant except between the 3-level discectomy with anterior plating and the 2-level corpectomy with anterior plating in axial rotation. There were no statistically significant differences between the 1-level discectomy and 1-level corpectomy with anterior plating and the 2-level corpectomy with anterior plating in any tested motion. There was also no statistical significance between the 3-level discectomy with anterior plating and the 2-level corpectomy with anterior plating and posterior fixation.

CONCLUSIONS

This study demonstrates that segmental plate fixation (3-level discectomy) affords the same stiffness and ROM as circumferential fusion in 2-level cervical spine corpectomy in the immediate postoperative setting. This obviates the need for staged circumferential procedures for multilevel cervical spondylotic myelopathy. Given that the posterior segmental instrumentation confers significant stability to a multilevel cervical corpectomy, the surgeon should strongly consider the placement of segmental posterior instrumentation to significantly improve the overall stability of the fusion construct after a 2-level cervical corpectomy.

Five-year follow-up evaluation of surgical treatment for cervical myelopathy caused by ossification of the posterior longitudinal ligament: a prospective comparative study of anterior decompression and fusion with floating method versus laminoplasty

STUDY DESIGN

Prospective, comparative clinical study.

OBJECTIVE

To compare the clinical outcome of anterior decompression and fusion with floating method and laminoplasty in the treatment of cervical myelopathy caused by ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

There have been no reports that have accurately and prospectively compared surgical outcomes after anterior decompression and posterior decompression.

METHODS

For cervical myelopathy caused by OPLL, we performed anterior decompression and fusion with floating method (ADF) in 1997, 1999, 2001, 2003, and 2004 and French-door laminoplasty (LAMP) in 1996, 1998, 2000, and 2002 at one institution. Twenty patients in the ADF group and 22 patients in the LAMP group were evaluated for 5 years' follow-up. The following criteria were evaluated: operation time, blood loss, complications, and Japanese Orthopedic Association score. For radiographic evaluation, canal narrowing ratio of OPLL, lordotic angle at C2-C7, and postoperative progression of the ossified lesion were measured.

RESULTS

The operation time in the ADF group was longer than that in the LAMP group. The average blood loss showed no statistical difference between the 2 groups. Complications occurred in 5 cases in the ADF group, but none occurred in the LAMP group. The mean Japanese Orthopedic Association score system for cervical myelopathy and the recovery rate in the ADF group were superior to those in the LAMP group, especially for cases with greater than 50% of the spinal canal compromised by OPLL or kyphotic alignment of the cervical spine, preoperatively. Postoperative progression of OPLL was observed in 5% of the ADF group and 50% of the LAMP group.

CONCLUSION

ADF is considered especially suitable for cases with massive OPLL and preoperative kyphotic alignment of the cervical spine, although it leads to a higher incidence of surgery-related complications compared with LAMP.

Middle-term results of a prospective comparative study of anterior decompression with fusion and posterior decompression with laminoplasty for the treatment of cervical spondylotic myelopathy

STUDY DESIGN

A clinical prospective study.

OBJECTIVE

To assess whether clinical and radiologic outcomes differ between anterior decompression and fusion (ADF) and laminoplasty (LAMP) in the treatment of cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

No reports to date have accurately and prospectively compared middle-term clinical outcomes after anterior and posterior decompression for CSM.

METHODS

We prospectively performed LAMP (n = 50) in 1996, 1998, 2000, and 2002, and ADF (n = 45) in 1997, 1999, 2001, and 2003. The Japanese Orthopedic Association (JOA) score, recovery rate, and each item of the JOA score were evaluated. For radiographic evaluation, the lordotic angle and range of motion (ROM) at C2-C7 and residual anterior compression to the spinal cord (ACS) after LAMP on magnetic resonance imaging were investigated.

RESULTS

Eighty-six patients (ADF n = 39; LAMP n = 47) could be followed for more than 5 years (follow-up rate 91.5%). Demographics were similar between the two groups. The mean JOA score and recovery rate in the ADF group were superior to those in the LAMP group from 2-year data collected after surgery. However, LAMP was safer and less invasive than ADF with respect to physical status and complications in the perioperative period. For individual items of the JOA score, the ADF group showed significantly more improvement of upper extremity motor function than the LAMP group (P < 0.05). There was a significant difference in maintenance of the lordotic angle in the ADF group compared with the LAMP group despite no difference in ROM.The LAMP group was divided into two subgroups: (1) LAMP(+) (n = 16) comprising patients who had ACS at 2 years after surgery, and (2) LAMP(-) (n = 31) comprising patients without ACS. Recovery rate differed significantly between the LAMP(+) and LAMP(-) groups despite there being no difference between the LAMP(-) and ADF groups.

CONCLUSION

The recovery rate of the JOA score in the ADF group was better than that in the LAMP group. The clinical outcomes after LAMP could be influenced by ACS.

Anterior hybrid decompression and segmental fixation for adjacent three-level cervical spondylosis

OBJECTIVE

To evaluate the outcomes of anterior hybrid decompression and segmental fixation for adjacent three-level cervical spondylosis.

METHODS

53 patients with adjacent three-level cervical spondylosis underwent anterior hybrid decompression and segmental fixation. Titanium mesh and PEEK cage were used to span the defects due to decompression and anterior locking plate was placed over the entire construct. Japanese Orthopedic Association (JOA) scores, segmental and C2-C7 angles before and after operation were analyzed.

RESULTS

The average follow up was 37.3 ± 7.0 months. Bone fusions were observed in all patients at follow-up intervals. JOA scores improved from preoperative 8.1 ± 2.2 (range 4-13) to 13.1 ± 2.3 (range 7-16) at final follow-up (P = 0.000). Meanwhile, surgical segmental angle was significantly improved from preoperative 6.9 ± 8.3° (range -10.4° to 27.6°) to postoperative 16.3 ± 7.2° (range -2.0° to 37.6°)(P = 0.000), and C2-C7 angle from 9.7 ± 8.6° (range -9.9° to 27.4°) to 17.8 ± 7.7° (range -1.2° to 34.3°) (P = 0.000). Postoperative complications included C5 palsy, cerebrospinal fluid leakage, hematoma, and titanium mesh subsidence.

CONCLUSION

Anterior hybrid decompression and segmental fixation is a safe and effective procedure for adjacent three-level cervical spondylosis.

Outcomes of three anterior decompression and fusion techniques in the treatment of three-level cervical spondylosis

The purpose of this article is to compare the outcomes of three different anterior approaches for three-level cervical spondylosis. The records of 120 patients who underwent anterior approaches because of three-level cervical spondylosis between 2006 and 2008 were reviewed. Based on the type of surgery, the patients were divided into three groups: Group 1 was three-level anterior cervical discectomy and fusion (ACDF); Group 2 anterior cervical hybrid decompression and fusion (ACHDF, combination of ACDF and ACCF); and Group 3 two-level anterior cervical corpectomy and fusion (ACCF). The clinical outcomes including blood loss, operation time, complications, Japanese Orthopedic Association (JOA) scores, C2-C7 angle, segmental angle, and fusion rate were compared. There were no significant differences in JOA improvement and fusion rate among three groups. However, in terms of segmental angle and C2-C7 angle improvement, Group 2 was superior to Group 3 and inferior to Group 1 (all P < 0.01). Group 2 was less in operation time than Group 3 (P < 0.01) and more than Group 1 (P < 0.01). Group 3 had more blood loss than Group 1 and Group 2 (all P < 0.01) and had higher complication rate than Group 1 (P < 0.05). No significant differences in blood loss and complication rate were observed between Group 1 and Group 2 (P > 0.05). ACDF was superior in most outcomes to ACCF and ACHDF. If the compressive pathology could be resolved by discectomy, ACDF should be the treatment of choice. ACHDF was an ideal alternative procedure to ACDF if retro-vertebral pathology existed. ACCF was the last choice considered.

The stabilizing potential of anterior, posterior and combined techniques for the reconstruction of a 2-level cervical corpectomy model: biomechanical study and first results of ATPS prototyping

Clinical studies reported frequent failure with anterior instrumented multilevel cervical corpectomies. Hence, posterior augmentation was recommended but necessitates a second approach. Thus, an author group evaluated the feasibility, pull-out characteristics, and accuracy of anterior transpedicular screw (ATPS) fixation. Although first success with clinical application of ATPS has already been reported, no data exist on biomechanical characteristics of an ATPS-plate system enabling transpedicular end-level fixation in advanced instabilities. Therefore, we evaluated biomechanical qualities of an ATPS prototype C4-C7 for reduction of range of motion (ROM) and primary stability in a non-destructive setup among five constructs: anterior plate, posterior all-lateral mass screw construct, posterior construct with lateral mass screws C5 + C6 and end-level fixation using pedicle screws unilaterally or bilaterally, and a 360° construct. 12 human spines C3-T1 were divided into two groups. Four constructs were tested in group 1 and three in group 2; the ATPS prototypes were tested in both groups. Specimens were subjected to flexibility test in a spine motion tester at intact state and after 2-level corpectomy C5-C6 with subsequent reconstruction using a distractable cage and one of the osteosynthesis mentioned above. ROM in flexion-extension, axial rotation, and lateral bending was reported as normalized values. All instrumentations but the anterior plate showed significant reduction of ROM for all directions compared to the intact state. The 360° construct outperformed all others in terms of reducing ROM. While there were no significant differences between the 360° and posterior constructs in flexion-extension and lateral bending, the 360° constructs were significantly more stable in axial rotation. Concerning primary stability of ATPS prototypes, there were no significant differences compared to posterior-only constructs in flexion-extension and axial rotation. The 360° construct showed significant differences to the ATPS prototypes in flexion-extension, while no significant differences existed in axial rotation. But in lateral bending, the ATPS prototype and the anterior plate performed significantly worse than the posterior constructs. ATPS was shown to confer increased primary stability compared to the anterior plate in flexion-extension and axial rotation with the latter yielding significance. We showed that primary stability after 2-level corpectomy reconstruction using ATPS prototypes compared favorably to posterior systems and superior to anterior plates. From the biomechanical point, the 360° instrumentation was shown the most efficient for reconstruction of 2-level corpectomies. Further studies will elucidate whether fatigue testing will enhance the benefit of transpedicular anchorage with posterior constructs and ATPS.