Anterior decompressive microsurgery and osteosynthesis for the treatment of multi-segmental cervical spondylosis. Pathophysiological considerations, surgical indication, results and complications: a survey

Noninstrumented Free Fibula Flap for Cervical Osteomyelitis

BACKGROUND AND IMPORTANCE

Severe cases of cervical vertebral osteomyelitis can pose a challenge regarding reconstruction, stability/alignment, and infection eradication. Here we describe the application of vascularized free fibula (FF) flaps to reconstruct the cervical spine without instrumentation in the setting of severe osteomyelitis.

CLINICAL PRESENTATION

Two patients presented with symptomatic multilevel cervical osteomyelitis. Both patients were treated with corpectomy and FF flap without instrumentation using a novel wedging and distraction technique to secure the flap into position. Clinical outcomes were based on neurological recovery and infection management. Computed tomography (CT) and CT angiography with 3-dimensional reconstruction were used to measure fusion status and patency of the anastomoses. CT of the cervical spine completed 8 weeks postoperatively demonstrated robust fusion of the fibula flaps to adjacent cervical vertebrae. In both patients, CT angiography demonstrated patency of the arterial anastomoses. Both flaps maintained persistent deformity correction. Both patients made full neurological recovery.

DISCUSSION

This reconstructive approach represents a salvage technique that offers advantages in cases of prior hardware failure or unfavorable host factors with rapid fusion and definitive treatment with a single surgery.

CONCLUSION

The use of FF flap without instrumentation seems to be a safe and effective option for cervical spine reconstruction in the setting of severe osteomyelitis.

[PEEK cage fusion after anterior cervical corpectomy : Clinical and radiological results in patients with spondylotic myelopathy]

BACKGROUND

Anterior cervical corpectomy and fusion (ACCF) has become a standard procedure for patients with spondylotic myelopathy due to multisegmental stenosis of the cervical canal. In addition to the fusion technique using autogenous bone grafts and titanium implants, synthetic polyetheretherketone (PEEK) cages have been used increasingly during the last years. However, limited evidence on the clinical and radiological results of PEEK cages for ACCF exists in the literature. The study presented here is the largest series to date reporting clinical and radiological outcome as well as complication rates after one to three-level ACCF using PEEK cages augmented by an anterior plate-screw osteosynthesis.

MATERIALS AND METHODS

Retrospective study on 101 patients after stand-alone PEEK cage-ACCF with a minimum follow-up of 6 months. The number of hardware failures and implant-related surgical revisions were determined. The rate of subsidence and fusion and the course of lordotic alignment were analysed. The neck disability index (NDI) and the European myelopathy score (EMS) were assessed.

RESULTS

Screw complications were detected in 8/101 cases and 3 cases of cage dislocation occurred, resulting in an overall implant related revision rate of 2.9 % (all revision cases showed cage dislocation). The rate of cage subsidence >3 mm was 12 % and solid fusion was achieved in 82 % of the patients. NDI, EMS and lordotic alignment improved significantly.

CONCLUSIONS

PEEK cages are a safe and effective alternative to titanium cages or autogenous bone graft for ACCF. Further randomized evaluation of different fusion techniques in ACCF is still necessary.

Operative techniques for cervical radiculopathy and myelopathy

The surgical treatment of cervical spondylosis and resulting cervical radiculopathy or myelopathy has evolved over the past century. Surgical options for dorsal decompression of the cervical spine includes the traditional laminectomy and laminoplasty, first described in Asia in the 1970's. More recently the dorsal approch has been explored in terms of minimally invasive options including foraminotomies for nerve root descompression. Ventral decompression and fusion techniques are also described in the article, including traditional anterior cervical discectomy and fusion, strut grafting and cervical disc arthroplasty. Overall, the outcome from surgery is determined by choosing the correct surgery for the correct patient and pathology and this is what we hope to explain in this brief review.

Intervertebral disc replacement for cervical degenerative disease--clinical results and functional outcome at two years in patients implanted with the Bryan cervical disc prosthesis

BACKGROUND

This is a prospective study of patients with degenerative cervical disease who underwent ventral discectomy and disc replacement with the Bryan((R)) cervical disc prosthesis. The objective was to investigate clinical outcome at 2 years of patients implanted with the Bryan disc and to evaluate function of the implant itself.

METHODS

Fifty-four consecutive patients with cervical disc herniation and/or spondylosis with preserved mobility in the affected spinal segments were enrolled. Patients presented clinically with cervical radiculopathy and/or myelopathy with or without neck pain. A standard anterior cervical discectomy was carried out and a Bryan disc was implanted in the affected levels. A total of 59 prosthetic discs were implanted, in 49 patients at a single level and in 5 at two adjacent levels. The neurological status was evaluated pre-operatively and at one and two years thereafter. Plain X-rays, CT, and MRI were used for pre-operative diagnostics. Post-operative follow-up was done by X-rays.

FINDINGS

All patients had an excellent or good neurological outcome according to the Odom criteria. Loss of function (motion range <3 degrees) was found in 7 (12%) out of 59 Bryan discs at two years after surgery. Heterotopic ossification (HO) of the McAffee grades 1-4 was seen in a total of 17 (29%) segments. There were no implant dislocations or migrations.

CONCLUSIONS

Implantation of the Bryan disc resulted in excellent or good neurological outcome in all patients. The surgical technique was safe and without complications. Twelve percent of the implanted Bryan discs lost mobility at two years, mainly due to HO. A trend was seen towards development of HO in the operated segments. Further investigations with longer follow-up periods and with a control group (e.g. fusion with intervertebral cage) will be necessary for a definitive assessment of the long-term functionality and benefits of artificial cervical discs.

Cervical corpectomy and strut grafting

Cervical corpectomy and strut grafting is a deceptively simple procedure that has been performed for many years for a variety of cervical spine disorders (infection, neoplastic disease, and trauma) but most commonly for cervical spondylosis. The procedure requires attention to detail to ensure adequate decompression of the neural structures and avoiding injury to the soft tissues of the neck and the vertebral artery in the transverse foramina. The following description of the technique is one we have successfully used for cervical corpectomy and strut grafting. We also discuss patient selection criteria, avoidance of common complications, and postoperative management.

Expandable cylindrical cages in the cervical spine: a review of 22 cases

Object

Expandable cylindrical cages (ECCs) have been utilized successfully to reconstruct the thoracic and lumbar spine. Their advantages include ease of insertion, reduced endplate trauma, direct application/maintenance of interbody distraction force, and one-step kyphosis correction. The authors present their experience with ECCs in the reconstruction of the cervical spine in patients with various pathological conditions.

Methods

Data obtained in 22 patients were reviewed retrospectively. A standard anterior cervical corpectomy was performed in all cases. Local vertebral body bone was harvested for use as graft material. Patients underwent pre- and postoperative assessment involving the visual analog scale (VAS), Nurick grading system for determining myelopathy disability, and radiographic studies to determine cervical kyphosis/lordosis and cage subsidence. Fusion was defined as the absence of motion on flexion–extension x-ray films.

Sixteen patients presented with spondylotic myelopathy, two with osteomyelitis, two with fracture, one with tumor metastasis, and one with severe stenosis. Fourteen patients underwent supplemental posterior spinal fusion, seven underwent single-level corpectomy, and 15 patients underwent multilevel corpectomy. No perioperative complications occurred. The mean follow-up period was 22 months. In 11 patients with preexisting kyphosis (mean deformity +19°), the mean correction was 22°. There was no statistically significant difference in subsidence between single- and multilevel corpectomy or between 360º fusion and anterior fusion alone. The VAS scores improved by 35%, and the Nurick grade improved by 31%. The fusion rate was 100%.

Conclusions

The preliminary results support the use of ECCs in the cervical spine in the treatment of patients with various disease processes. No significant subsidence was noted, and pain and functional scores improved in all cases. Expandable cylindrical cages appear to be well suited for cervical reconstruction and for correcting sagittal malalignment.

Anterior cervical corpectomy for cervical spondylotic myelopathy: Experience and surgical results in a series of 70 consecutive patients

Recently the debate over the management of cervical spondylotic myelopathy (CSM) has regained interest; more specifically whether treatment should be operative versus non-operative, raising the question about the real effectiveness of surgery in influencing the natural history of this pathology and about the choice of the most appropriate approach (anterior vs. posterior). The authors report a retrospective review of 70 consecutive patients who underwent elective anterior cervical corpectomy and fusion with iliac crest autograft or titanium mesh and placement of an anterior cervical plate for the treatment of CSM. The patients underwent pre-and postoperative evaluation, including history, and physical and neurological examination. Patients were also evaluated pre-and postoperatively using a modified version of the Japanese Orthopedics Association Scale (mJOA), which provides a fine semi-quantitative graded evaluation of overall function. Upon discharge home, patients were followed for an average of 42 months (range, 12-63 months). Following an anterior cervical decompression of the spinal cord, 94.2% of patients improved their functional status and 5.8% were unchanged; the mean preoperative mJOA score of all patients was 12.2, the postoperative was 15.4 and the amelioration was also documented by neurophysiological studies which showed an increase in amplitude and decrease in latency of somatosensory evoked potentials and motor evoked potential in 47 patients (67%). Older age and longer duration of preoperative symptoms both were not associated with a lower postoperative mJOA score (p < 0.47, p < 0.29, respectively). Single versus multiple level decompression was not predictive of a lower postoperative mJOA score (p < 0.18). Preoperative spinal cord low signal intensity changes on T1-weighted MRI were related to a lower postoperative mJOA score (p < 0.05), whereas spinal cord high-signal intensity changes on T2-weighted MRI were related to a higher postoperative mJOA score (p < 0.01); finally a lower preoperative mJOA score was highly predictive of a lower postoperative mJOA score (p < 0.0005). Anterior cervical corpectomy and fusion for CSM appears to be an effective procedure with a more favorable neurological improvement when compared to posterior decompressive laminectomy, minimally invasive procedures or non-surgical treatment. It is also a safe procedure even in the elderly population, with low morbidity and the potential for permanent spinal cord decompression and excellent bone stability.

Anterior decompression for cervical spondylotic myelopathy

Cervical spondylotic myelopathy is a clinical entity that manifests itself due to compression and ischemia of the spinal cord. The goal of treatment is to decompress the spinal cord and stabilize the spine in neutral, anatomical position. Since the obstruction and compression of the cord are localized in front of the cord, it is obvious that an anterior surgical approach is the preferred one. The different surgical procedures, complications, and outcome are discussed here.

Surgery for postarthrodesis adjacent–cervical segment degeneration

Anterior cervical decompression and fusion has gained popularity because of its applicability to a variety of cervical spine disorders. The authors of long-term follow-up studies have demonstrated the development of degenerative changes in segments adjacent to fusion. So-called adjacent-segment disease causes symptomatic deterioration in up to 25% of the patients who have undergone anterior cervical decompression and fusion for cervical spondylotic myelopathy. The causes of this condition are debated in the literature. The authors provide a review of the available literature on the pathogenesis, prevention, and treatment of postarthrodesis adjacent-segment degenerative disease.

Treatment of multilevel cervical spondylotic myeloradiculopathy with posterior decompression and fusion with lateral mass plate fixation and local bone graft

This is a retrospective review of 32 patients with multilevel cervical myelopathy treated by laminectomy and lateral mass plate fusion. The prognosis of surgically treated myelopathy is evaluated as well as prognostic factors for recovery of myelopathy. Diagnoses included cervical spondylosis or ossification of the posterior longitudinal ligament. Final follow-up was at 15.2 months (mean) postoperatively. Myelopathy was graded preoperatively and postoperatively by the system of Nurick. All patients had preoperative radiographs and magnetic resonance imaging (MRI). The presence of abnormal T2-weighted MRI signal (myelomalacia) was noted. Postoperative studies included flexion-extension radiographs to assess fusion and MRI to evaluate decompression of neural elements and resolution of myelomalacia. Severity of preoperative Nurick myelopathy, presence of myelomalacia, and age were evaluated as potential prognostic indicators for surgically treated myelopathy. Mean Nurick score improved from 2.6 (range 1-4) to 1.8 (range 0-3) postoperatively (p < 0.0001). Twenty-two patients (71%) had improvement in Nurick grade of at least one point, and nine showed no improvement. No patients had deterioration of Nurick grade. Preoperative myelomalacia was noted in 15 (47%) patients, and all 15 had residual myelomalacia postoperatively. Severe myelopathy, age, and myelomalacia had no prognostic value for improvement of myelopathy. Complications included pseudarthrosis (3%), wound infection (9%), and transient C5 palsy (6%). This study demonstrates excellent outcomes from laminectomy and fusion in multilevel cervical myelopathy. A high rate of improvement of myelopathy was observed, neurologic deterioration did not occur, and complication rates were low. Severe myelopathy and myelomalacia on preoperative MRI had no prognostic value.

Vertebral autograft used as bone transplant for anterior cervical corpectomy: technical note

OBJECTIVE

In this prospective patient study, we used a surgical technique for autograft bone fusion during anterior cervical corpectomy (ACC) in patients experiencing cervical spondylotic myelopathy. We packed the resected bone material of the corpectomy into a titanium mesh cage. To evaluate the efficacy of our autograft technique, we analyzed the results according to neurological outcome, radiological outcome, and complications.

METHODS

Between 1995 and 1998, 27 ACC operations were performed for cervical spondylotic myelopathy caused by multisegmental cervical spondylosis. In all patients, decompression of the cervical canal and/or spinal nerve roots was performed by a median cervical corpectomy by an anterior approach. After the ACC was completed, a titanium mesh cage, which was variable in diameter and length, was filled with morselized and impacted bone material from the cervical corpectomy and was then implanted. An anterior cervical plate was placed in all patients to achieve primary stability of the cervical vertebral column. Age, sex, pre- and postoperative myelopathy, number of decompressed levels, radiological results, and complications were assessed. The severity of myelopathy was graded according to the scoring system of the Japanese Orthopaedic Association.

RESULTS

Symptomatic improvement of neurological deficits was achieved in 80% of the patients. The mean preoperative Japanese Orthopaedic Association score improved from 13.1 to 15.2 postoperatively (P < 0.05). No patient demonstrated worsening of myelopathic symptoms. Radiological follow-up studies demonstrated complete bony fusion in all patients. A vertical movement of 2.25 +/- 0.43 mm of the titanium cage into the adjacent vertebral bodies was observed in 24 patients. In patients with either a lordotic or neutral cervical spinal axis postoperatively, the axis remained unchanged during the entire follow-up period.

CONCLUSION

The results of this study demonstrate that transplantation of autograft bone material harvested during the ACC integrated well in the cage and in the adjacent vertebral bodies. Thus, complications associated with explantation of autograft material from other donor sites, e.g., the iliac crest, could be avoided. The early postoperative and midterm follow-up periods provided no evidence of morphological or functional instability of the operated cervical segments when this autograft technique was used in combination with cervical instrumentation.

Anterior cervical corpectomy and strut graft fusion using a different method

BACKGROUND CONTEXT

Strut graft fusion after corpectomy is frequently indicated for certain pathologies in the cervical spine. The "key-hole" technique and "dove-tail" technique are the popular methods used to insert the strut graft at present. Segmental collapse secondary to seating of the graft on cancellous bone and cord injury from placement or dislodgement the graft are our concerns. Our method was designed to solve these possible problems without affecting the arthrodesis.

PURPOSE

To evaluate the results of this method that allows the graft to seat on both the hard end plate and cancellous bone of the upper and lower contacting vertebrae in a easy and safe way after varying levels of corpectomy in the cervical spine.

STUDY DESIGN

A retrospective clinical and radiographic study conducted by an independent observer was performed on 23 patients treated with this different strut grafting method after cervical corpectomy, with at least 2 years of follow-up.

PATIENT SAMPLE

A total of 23 patients from 1983 to 1994 underwent fusion using our strut grafting method with fibular allograft packed with autogenous bone. No augmented internal instrumentation was used in all these patients. The patients with an incomplete record or less than 2 years of follow-up were excluded beforehand.

OUTCOME MEASURES

Clinical outcome was assessed by a score based on three factors: neck pain, dependence on medicine and ability to return to work. The total score of these factors was seven. A score from 0 to 3 was defined as satisfactory, and a score from 4 to 7 was defined as unsatisfactory. The result of graft fusion, collapse of interbody height and loss of lordotic angle corrected by the graft were evaluated through the radiographic studies.

METHODS

The operative technique creates a notch in the anterior cortex and end plate of the respective superior and inferior vertebraes. Cylinder allograft filled with autogenous cancellous bone was used as bone graft for all patients. The bone graft is cut with corresponding pegs at both ends. The graft is inserted into the corpectomy space with the pegs inserted into the notches and the remainder of the graft placed onto the preserved superior and inferior bony end plates.

RESULTS

Twenty patients achieved successful fusion (87%). On average, the loss of anterior and posterior interbody height was 2.79 mm and 2.93 mm, respectively. The average loss of lordotic correction was 2.83 degrees. Eighty-three percent achieved satisfactory clinical outcomes. There were no neurologic injuries encountered during the operation. Partial graft dislodgment occurred in two patients (8.7%).

CONCLUSIONS

This different method of strut grafting after cervical corpectomy has proven its safety and efficacy in its fusion and clinical results.

Recurrent laryngeal nerve injury with anterior cervical spine surgery risk with laterality of surgical approach

STUDY DESIGN

A detailed review of anterior cervical fusion procedures from a university-based spine specialty service was completed. Noted were the laterality of approach, number of levels, discectomy or corpectomy, use of instrumentation, and cases of reoperation.

OBJECTIVES

The primary purpose of the study is to determine whether there is in fact a greater risk of recurrent laryngeal nerve (RLN) injury with approach on the right or left side. Also evaluated is the risk with corpectomy, reoperative procedures, and instrumentation.

BACKGROUND

Anatomic considerations have been used as justification to determine the side of surgical approach. However, few clinical studies have delineated the side of surgical approach in their results.

METHODS

A total of 328 anterior cervical spine fusion procedures completed between 1989 and 1999 were reviewed. All speech changes reported were noted throughout follow-up.

RESULTS

There were 187 anterior discectomy and 141 corpectomy procedures. There were 21 reoperative anterior fusions. There were 173 procedures completed from the right side and 155 from the left. There were nine patients documented to have dysphonia after surgery. Five had a left-sided approach and four had a right-sided approach.

CONCLUSIONS

The incidence of RLN symptoms after surgery was 2.7% (9 of 328). The incidence of RLN symptoms was 2.1% with anterior cervical discectomy, 3.5% with corpectomy (5 of 141), 3% with instrumentation (8 of 237), and 9.5% with reoperative anterior surgery (2 of 21). There was a significant increase in the rate of injury with reoperative anterior fusion. There was no association between the side of approach and the incidence of RLN symptoms.

Anterior cervical fusion with the Orion locking plate system

STUDY DESIGN

This study was conducted to evaluate an anterior cervical fusion plate system, the Orion locking plate, regarding its surgical handling, hardware-related failures, and short-term and long-term results.

OBJECTIVES

A comprehensive evaluation of the implant in a broad range of patients with cervical spine diseases.

SUMMARY OF BACKGROUND DATA

Locking plates are the most recent devices for achieving anterior cervical spinal fusion and offer considerable advantages such as faster and easier implantation and fewer implant-related failures than older plate systems.

METHODS

Ninety-six patients were investigated. All underwent anterior cervical plate fusion as a component of the surgical treatment for symptomatic degenerative cervical spinal disease or for vertebral destruction caused by trauma, tumor, or inflammation. Besides plate fixation, 6 of the 96 patients had a combined ventrodorsal fusion. In 28 cases, one or more vertebral bodies were removed and replaced with titanium place-holders. The remaining 62 patients were first treated by intervertebral inlay placement, and the fused segments were subsequently plated. Neurologic signs and symptoms were evaluated before and after surgery and during a follow-up period of at least 1 year.

RESULTS

The rate of neurologic improvement was highest in radiculopathy patients and lowest in patients with severe myelopathy. In all cases, control radiographs demonstrated a solid bony fusion. Clinical deterioration after surgery was seen in four cases of severe myelopathy in which considerable neurologic deficits existed before surgery, possible because of rapid decompression of the cord and associated microvascular alterations. In two of these cases, there was long-term improvement. Additional general complications caused by surgical retraction included temporary swallowing disturbance in seven patients and a large wound hematoma in one. Hardware failures were encountered in three cases, all of them caused by improper implantation technique and not material failure, per se.

CONCLUSION

In the study group, the Orion locking plate was easy to use, failure-free if properly implanted, safe for the patient and supported solid bony fusion in every case.