Centre Hospitalo-Universitaire de Bordeaux, Service de Pathologie du la Colonne Vertébrale, Bordeaux, France.

Assessment of cervical lordosis using a standardised digital acquisition procedure in the normal population

Three independent reviewers measured static lordosis. The EOS¯ system, which utilises low dose radiation and provides reliable standardized digital 2D acquisition with 3D reconstruction was employed. Measurements were carried out twice by every examiner on two different occasions.

Cohort of the general public of 180 subjects divided into 4 groups (both sexes individually, age less than 40 and greater than 50 individually). None had any previous history of spinal disorders or sagittal imbalance. General cervical lordosis (C2 to C7) as well as upper and lower cervical lordosis were assessed.

Cervical lordosis in the general population has a very wide range in both sexes. Overall cervical lordosis was 37 degrees. Lower cervical lordosis (superior endplate of C4 to inferior endplate of C7) demonstrated an average of 16 degrees, and upper cervical lordosis was found to be 21 degrees.

No particular age group or sex was more prone to having lesser/greater lordosis.

Current literature is sparse and provides large ranges, different standards and variable methods for assessing standard cervical lordosis. Overall cervical lordosis is very variable amongst the sexes and age groups. We provide a standard set of values which help to provide the spinal surgeon with values to aim for when seeking to restore cervical lordosis.

Purpose of the study: Revision surgery for scoliosis in adults is a technical challenge. Indications include flat back, non-union, and syndromes adjacent to the instrumentation The purpose of this work was to evaluate the pertinence of the transforaminal lumbar interbody fusion (TLIF) method for revision surgery for scoliosis in adults.

Material and methods: In our spinal surgery unit, 23 patients underwent revision surgery for thoracolumbar and lumbar scoliosis. A unique posterior approach was used. The TLIF was performed systematically at the lumbosacral level, at the non-union when it was present, and at the level of the Smith-Petersen osteotomies, as well as the levels above and below a transpedicular osteotomy. Seventeen patients presented flat back, ten non-union, five degenerative disease distal to the instrumentation and one degeneration proximal to the instrumentation. Nine patients had several indications for surgical revision. Five transpedicular osteotomies were performed in five patients.

Results: Mean follow-up was 30 months (range 18–48). On average 2.3 levels (range 1–4) were involved in the TLIF. The fusion was extended to the sacrum in 22 patients. The mean operative time was 5h50m (range 3–8 hours). Mean blood loss was 2100ml (400–4500). Postoperative lumbar lordosis (L1S1) was 53.5°, giving an improvement of 23° copared with the preoperative lordosis. Among the postoperative complications, there was one neurological complications which recovered partially at last follow-up one case of deep infection of the operative site which require partial removal of the implants and one case of recurrent non-union. There was no loss of correction in the frontal or sagittal planes with the exception of one patient who developed an infection. None of the patients in the series required complementary anterior surgery.

Conclusion: For revision surgery of scoliosis in the adult, a circumferential arthrodeis is needed to maintain the fusion. The TLIF method has the advantage of allowing intersomatic fusion via the posterior approach alone without opening the spinal canal. We consider that the TLIF technique is an alternative to two-phase procedures for revision surgery for scoliosis in adults. This method has given a good percentage of fusion in our series with little loss of correction.

Purpose of the study: Multisegmentary pedicle screws are becoming increasingly popular for idiopathic scoliosis in adolescents. For several years correction of the axial deformity has been achieved by vertebral rotation. Use of the EOS radiographic system and the sterEOS software enables a precise calculation of the vertebral rotation in the different plans while exposing the patient to reduced radiation doses. The purpose of this study was to determine the efficacy of the vertebral rotation technique for the correction of axial rotation of the apical vertebra (ARAV).

Material and method: This was a comparative prospective study. Two groups of ten patients underwent surgery for idiopathic scoliosis of the thoracic spine (Lenke 1 and 3). A posterior procedure was performed in all cases to achieve insertion of multiple level pedicle screws. In group 1, the correction was achieved by rotation of the rod and in group 2 by translation and veterbral rotation using the vertebral column manipulation (VCM) technique. Preoperative and 3-month postoperative EOS images were analysed by a radiologist and the spinal surgeon, both blinded to the operative technique. Two radiological parameters were analysed and compared. ARAV was calculated using the pelvic reference; any position error at image acquisition was thus automatically corrected.

Results: Mean age at surgery was 14 years (range 11–19); the two groups were not significantly different for epidemiological parameters, duration of hospital stay, type of curvature, preoperative radiological parameters, axial rotation of the apical vertebra preoperatively, and number of vertebrae instrumented or correction of the curvatures. The postoperative ARAV was significantly greater in group 1 (12.4 vs 4.3, p=0.0005) and the ARAV correction was significantly greater in group 2 (13.7 vs 4.5, p=1.9E-5). There were no early postoperative complications in either group.

Discussion: For posterior surgical correction of thoracic or double major idiopathic scoliosis, the VCM technique allows better correction of the ARAV compared with the rod rotation technique. Use of the EOS and the sterEOS software enabled a better evaluation and comprehension of the 3D correction while exposing the patients to a smaller radiation dose.

Purpose of the study: Discectomy-anterior fusion has proven efficacy for many diseases of the cervical spine. Nevertheless, the loss of motion and the over-solicitation of adjacent levels are arguments in favor of disc replacement. This prospective study examined the early clinical and radiological results obtained in the first 41 patients treated with a new cervical disc prosthesis, Mobi-C.

Material and methods: A prospective multicentric clinical and radiological study is being conducted to analyze the safety and efficacy of Mobi-C for degenerative disease. Indications are radiculopathies due to discal herniation or foraminal osteophytic stenosis involving one or two levels from C3 to T1. An independent observer reviewed the patients. SF36, the Neck Disability Index, and a visual analogue scale for pain as well as radiographic mobility were noted.

Results: Mean age was 42 years (range 31–56 years). There were 23 men and 18 women. Eight patients had two disc replacements. Mean follow-up was six months (range 3–10 months). Mean operative time was 65 min, similar to operative time for fusion. Blood loss was 90 ml. NSAID were prescribed for the first 15 days. There were no intraopeartive complications and no revisions. Postoperative complications were minimal. There were no specific complications related to the prosthesis, its insertion or its function. The function and quality-of-life scores showed a significant improvement at last follow-up. Radiographically, motion was also improved in most patients.

Discussion: The early results on the safety and efficacy of this new cervical prosthesis are promising. Primary stability has been excellent and there have been no specific prosthesis-related complications. Furthermore, several operators have mentioned how easy it is to insert the Mobi-C.

Conclusion: The clinical results in terms of pain and function as well as the radiological results have been satisfactory both at the early and at the later assessments. Insertion of this prosthesis is a simple process, similar to insertion of an intersomatic cage, elements arguing in favor of a cervical disc prosthesis. Further follow-up will be needed to assess the long-term efficacy and possible effect on prevention of accelerated degeneration of the adjacent discs.

Purpose: We examined our preliminary results in a series of nine patients treated for thoracolumbar callus deformitis using a technique associating simultaneous anterior and posterior approaches and in situ contourning.

Material and methods: The series included seven women and two men, mean age 42 years operated on after January 2001. The patients had deformed callus after fractures (n=8) or spondylodiscitis (n=1). Surgical treatment was used initially for five of the fracture patients. The deformed callus involved the thoracolumbar junction in 56% of the patients. Mean follow-up was 14 months (6–22). The same surgical technique was used in all nine patients by two surgery teams. The patient was positioned in lateral decubitus. After posterior arthrectomy and anterior osteotomy, the correction was obtained by combined anterior distraction and lordosis contourning of the posterior material. An intercorporeal graft was encastrated anteriorly.

Results: Preoperative regional kyphosis was 30°. It was 4° postoperatively and 5° at last follow-up. Kyphosis improved in 87% of patients. There was no neurological aggravation. The main complication was posterior infection with aggravation of the regional kyphosis to 10° in one patient.

Discussion: Posterior or anterior spinal approach, alone or in combination have been proposed for callus deformitis of the spine. Results in the literature have shown moderate and incomplete correction of the kyphosis.

Conclusion: The proposed technique allows good reduction of the deformed callus with results that appear to persist with time.

Purpose: Calcified thoracic discal herniation is an uncommon entity. The purpose of this study was to analyse the population concerned to search for radiological signs of sequellar Scheuermann disease and the characteristic features of hernias in this context and to compare computed tomography (CT) and magnetic resonance imaging (MRI) findings with intraoperative and histological findings.

Material and methods: A retrospective series of 13 patients with symptomatic calcified thoracic discal herniation (CTDH) who underwent surgery from 1996 to 2001 was analysed. Mean age was 50.7 years. The population included ten men and three women. CT was performed in all cases, with myelography in two. MRI was performed in eleven cases with DTPA-gadolinium injection in six. Two neuroradiologists blinded to intraoperative findings reviewed the images independently to search for radiological signs predictive of dural adherence and/or penetration and the presence of Scheuermann squellae. Pathology data were available for five patients.

Results: All herniations occurred in the mid to lower thoracic level in patients in their fourth or fifth decade. The disk was calcified at the zone of herniation in all cases. The hernia occupied more than half of the spinal canal in 70% of patients. The nature of the lesion was analysed on axial CT and T1/T2 weighted MRI sequences with fat suppression. Images confirmed the pathological findings: the majority of the calcified herniations were composed of mature haversian bone. In ten of the eleven cases, the radiological interpretation of the hernia/dural interface was found to correspond to the intraoperative observation.

Discussion: The sensitivity and specificity of T2 weighted MRI with gadolinium injection of the hernia/dural interface is superior, enabling prediction of dural penetration. Sequellae of Scheuermann disease found in five patients confirmed a probably non-fortuitous association.

Conclusion: The natural history of CTDH starts with discal calcification in a degenerative spine during posterior migration, followed by bone metaplasia which can involve neighbouring structures such as the longitudinal ligament and lead to penetration of the dura by the mature ossified lesion.

Purpose: The biomechanical behaviour of the cervical spine was studied in vitro with an optoelectronic system in order to better understand its physiology.

Material: Twenty fresh cervical spines (occiput-D1) from fourteen men and six women, mean age 66.5 years, were sterilised with ß radiation (2.5 Mrad) and stored at −24°C then studied after slow thawing and excision of the paraspinal muscles.

Methods: Three-point reflecting markers were rapidly attached to each vertebral segment (4 or 5 vertebrae). The inferior vertebra was blocked. Six pure moment couples (2 N.m maximum, 10 increments) were applied in the three anatomic planes using a loading device lodged on the superior vertebra. Displacements were measured with the VICON 140 using a kinematic software.

Results: The three-dimensional behaviour curves of each functional unit (FU) were recorded for each solicitation to analyse the principal movement and coupled movements (maximum mobility, neutral zones, rigid zones, rigidity). Mean maximal flexion-extension movements were C0/C1= 28.7°; C1/C2 = 22.3°; C2/C3 = 7.3°; C3/C4 = 10.6°; C4/C5 = 13.8°; C5/C6 = 13.4°; C6/C7 = 10.8°; C7/T1 = 6.4°. Maximum overall lateral inclinations were: C0/C1= 8.7°; C1/C2 = 9.3°; C2/C3 = 8.7°; C3/C4 = 6.7°; C4/C5 = 10.5°; C5/C6 = 12.2°; C6/C7 = 8.6°; C7/T1 = 5.7°. Maximal overall axial rotations were: C0/C1= 11°; C1/C2 = 71°; C2/C3 = 9.5°; C3/C4 = 10.8°; C4/C5 = 12.3°; C5/C6 = 9°; C6/C7 = 5.6°; C7/T1 = 5.7°. All the FU exhibited flexion-extension movement. Lateral inclination coupled important controlateral rotation for C1/C2 and minimal ipsilateral rotation (< 10°) in the lower FU of the cervical spine. Axial rotation of the C1/T1 functional unit was coupled with homolateral rotation (< 10°).

Discussion: Our experimental protocol provided precision of < 1° and good reproducibility allowing simultaneous three-dimensional analysis of the spinal functional units. Making measurements without direct contact is particularly useful for the cervical spine. Our results are within the experimental corridor defined by Goel, Panjabi and Wen.

Conclusion: This work on a large number of functional units adds further support to data in the literature concerning the biomechanical behaviour of the cervical spine. Our protocol could be applied to analyse the impact of surgical procedures used for the cervical spine, particularly for the evaluation of new fixation systems or prostheses.

Purpose: A retrospective study of 17 fractures of the cervical spine in patients with ankylosing spondylitis is reported. The purpose of this study was to search for risk factors of fracture in ankylosing spondylitis an to assess treatment outcome.

Material and methods: Seventeen patients treated between 1982 and 2201 were reviewed with a mean follow-up of five years. There were three women and fourteen men, mean age 60 years at trauma. Fifteen patients underwent surgery and two were treated orthopaedically.

Results: This group of patients with ankylosing spondylitis with fracture of the cervical spine was homogeneous: age 60 years, disease duration 30 years, fracture due to fall. The fracture was at the C6/C7 level in 47% of the patients where the lever arm is the greatest and also a level that is difficult to explore, explaining the late diagnosis in 35% of the patients. Sixty percent of the patients were in Frankel classes D or E and 23% in classes A or B. Anterior fixation was used for 14 patients, posterior fixation in one. A long osteosynthesis involving several levels was used in all cases. Major kyphosis had developed in three patients after fracture which was not recognised initially; at fixation, an anterior wedge graft was inserted in the fracture line for correction. Mean correction was 20° with good restoration of the lordosis and rehorizontalization. Bone healing was achieved in all operated patients without loss of the reduction of the kyphosis at last follow-up. The neurological status did not worsen in any patient. Anterior fixation was insufficient to reduced an old fracture-dislocation in one patient who required posterior decompensation. Orthopaedic treatment was used in two patients: the first (Frankel A) died at two months and the second healed with a 10° aggravation of the cervical kyphosis. All the Frankel A and B patients in this series died.

Conclusion: All patients with severe neurological involvement died. The anterior approach, used alone, provided good stabilisation of the cervical spine. For the patients without neurological involvement, reduction of the cervical kyphosis should be associated with a stabilisation procedure in case of fracture with kyphosis.

Purpose: There is growing concern about the effect of anterior fusion of the cervical spine on the adjacent levels. Long-term assessment is indispensable to understand the mechanisms involved in the degradation observed and to support the development of materials preserving discal mobility.

Material: Three hundred patients who underwent cervical arthrodesis were reviewed in 1996 forty months after the procedure for physical examination and an x-ray work-up including stress views. Cervical spine and radicular pain were assessed on a visual analogue scale.

Methods: A complete data set was available for 136 patients and a partial set for 34. Twenty-two patients only accepted a phone interview. The clinical outcomes in these three groups were not significantly different and the mean scores for these three groups were in the general average in 1996. Eight patients had died.

Results: Patients were divided into three groups by type of disease diagnosed preoperatively (trauma, degenerative spine, myelopathy). Mean follow-up was 102.5 months (range 84 – 180 months).

Trauma: Among the 42 patient reviewed again in 2001, mean deterioration in the subjacent segment increased from 21% in 1996 to 69% in 2001. Deterioration of the supraja-cent segment increased from 26% to 47.6%. Cervical pain remained moderate (20/100 in 1996 and 27/100 in 2001). Degenerative spine (root compression requiring simple discectomy or with arthrodesis or single-level corporectomy): Among the 42 patients reviewed again in 2001, deterioration of the subjacent segment increased from 57% in 1996 to 89% in 2001. Deterioration of the suprajacent segment increased from 22% to 41%. Cervical pain increased from 14/100 in 1996 to 41/100 in 2001.

Myelopathy: Among the 52 patients reviewed again in 2001, deterioration of the subjacent segment increased from 54% in 1996 to 81% in 2001 when there had been one or two corporectomies and from 40% to 70% beyond two. Deterioration of the suprajacent segment increased from 26% to 50%. Cervical pain remained moderate (18/100 in 1996 and 23/100 in 2001).

Conclusion: Although a statistical analysis was not possible because of the small number of patients and the large percentage lost to follow-up, these results confirm that fusion of the cervical spine accelerates the degradation of adjacent levels. Longer follow-up demonstrates that the trauma group “catches up” with the degenerative group.

Use of mobile materials should enable differentiating between effects related to the degenerative process and those induced by the arthrodesis.

Purpose: The long Arnold nerve can be compressed at several sites. We analysed retrospectively eight patients who underwent surgery for Arnold’s neuralgia between January 1998 and June 2000. The purpose of our analysis was to determine the results of the neurolysis technique.

Material and methods: There were seven women and one man, mean age 52 years. Pain had progressed for more than one year (mean 3.5 years) and all patients had participated in long rehabilitation programmes. All had had at least one radioguided posterior injection at the C1–C2 level. Bilateral neurolysis was performed for patients with bilateral pain. The same surgical technique was used for all patients: desinsertion of the inferior oblique muscle from the lateral aspect of C2 and neurolysis of the posterior branch of C2 to the lower border of the inferior oblique muscle. When needed because of major osteoarthritis, C1–C2 fusion was achieved by posterior lacing.

Results: There were no per or postoperative complications. Neuralgia improved in all patients (70/100 to 20/100 on visual analogue scale). Pain relief was considerable for one female patient who had associated C1–C2 osteoarthritis. One patient complained of posterior joint pain at last follow-up. an anatomic cause of the compression was identified in three cases: osteophyte on the posterior part of the C1-C2 articulation, hypertrophy of the periradicular venous plexus, and passage of the Arnold nerve within the inferior oblique muscle with compression in a fibromuscular sheath.

Discussion: Several methods have been proposed to relieve Arnold’s neuralgia. Rehabilitation exercises and injections should, in our opinion, be attempted first. The Sturniolo procedure (unique desinsertion of the inferior oblique muscle) would be insufficient. We prefer to associate neurolysis at the C2 level because of the frequently associated anatomic anomalies.

Conclusion: Different sites can be involved in the compression of the Arnold nerve, warranting associated neurolysis.

Purpose of the study: We report a case of type 1 neurofibromatosis (von Recklinghausen’s disease) of the lower cervical spine in a 13-year-old girl.

Case report: There was no neurological deficit. Plain films showed dysplastic 82° kyphosis centered on the C4–C5 disc. Surgical treatment consisted in anterior multilevel interbody grafting and plate osteosynthesis combined with posterior arthrodesis. Good bone fusion was obtained with acceptable cervical mobility. The residual cervical kyphosis was 18°.

Discussion: An evaluation of the cervical spine should be proposed for patients with neurofibromatosis even if there is no thoracic scoliosis. Severe cervical deformities can lead to serious neurological complications. Circumferential arthrodesis appears to provide optimum results.