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.

Background: Long-term results after fusion for cervical disc disease show evidence of adjacent segment disease, mainly in young and active population. This led to the development of new techniques, i.e. cervical mobile prostheses. 8yr-follow-up of Cervidisc^® semi-constrained prosthesis documented motion preservation, but its design required minor adjustments to assess optimal outcome leading to an optimized version – Discocerv^® Cervidisc Evolution.

Purpose: To evaluate the intermediate outcome in patients operated with Discocerv^®.

Study design: Multicenter prospective non comparative study.

Patient sample: Since April 2006, 77 consecutive patients (41m/36w: mean age 45.2[27–65]) were enrolled in the study so far in 7 centers in France and Switzerland. Mean follow up was 6(0–12) months.

Outcome measures: Clinical evaluation criteria: VAS 1 to 100mm self-reported cervical and radicular pain, NDI (1–50 scale), symptoms evolution (ODOM score), work status, patient satisfaction were recorded pre–and post-operatively. Radiographic criteria: operated levels’ flexion-extension mobility.

Methods: Patients underwent one (C3C4 n=2, C4C5 n= 7, C5C6 n=37, C6C7 n= 28) or multiple level (C5C6/ C6C7 n=2; C4C5/C5C6/C6C7 n=1) cervical arthroplasty with Discocerv for degenerative disc diseases (disc hernia, stenosis, discopathy).

Results: Per-operative complications occurred in 4 patients (5%) without further consequences. No post operative complications were reported. 67% of active patients resumed their previous work within the first 6 months after surgery. The ODOM score showed 100% excellent and good results at 6 to 12mths follow-up.

Mean cervical and radicular VAS-reported pain decreased from 60 [4–84] and 65 [2–96] pre-operatively to 21[0–45] and 21[0–36] at 0–6 months and to 15 [0–40] and 16 [0–40] respectively at 6–12 months. Similarly mean NDI decreased from 25 [9–45] to 10 [0–35] at 0–6 months and to 6[0–36] at 6–12mths. All patients were satisfied with the results so far.

Quantitative radiographic analysis showed satisfactory restoration of cervical mobility at the operated levels with mean flexion-extension mobility 6.4°[1–11°] at 0–3mths and 7.1°[4–12°] at 6–12mths respectively. The adjacent level mobility was found within normal ranges at 6–12mths post-operatively. At the same follow-up period, the regional lordosis was within physiological ranges for 65% of patients at the last follow-up.

Discusssion and conclusion: Our results with Discocerv^® Cervidisc Evolution prosthesis confirm the long term 96% mobility obtained at 7 years follow-up with the first generation of the device, i.e. Cervidisc^®.

Both clinical and radiological findings in this study support the effectiveness of the Discocerv^® Cervidisc Evolution prosthesis at mid-term. However further follow-up at long term is necessary in order to confirm these findings.

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: 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: Access to the cervicothoracic junction is difficult both via a posterior and via an anterior approach. Tumour localisations or more rarely trauma however require access. Using the posterior approach, anterior decompression is limited by the narrow access and the vulnerability of the cord. Anterior reconstruction is impossible. Using the pure anterior approach, fixation and decompression of the caudal component is limited. Preoperative MRI shows the respective position of the manubrium sternal and the diseased vertebra, allowing a clear surgical strategy. To avoid sternotomy or even partial cleidectomy, both causes of postoperative pain and complications, we developed a medial sternal resection maintaining the stability of the sternoclavicular joints and allowing spinal decompression by corporectomy to T3 and fixation to T4.

Material and methods: A left anterolateral cervical approach was used to avoid injury to the recurrent nerve. This is a classical cervical approach generally used for access to C7-T1. It is prolonged caudally a few centimetres on the mid line to reach the anterior aspect of the sternum. After section of the sternohyoid, sternothyroid and scapulohyoid muscles, the three upper centimetres of the sternum are resected with a microdrill over a width of two centimetres. This give direct access to the anterior walls of T3 and T4. The lower limit of the exposure is described by the aortic arch (except in patients with severe kyphosis). The left brachiocephalic venous trunk is the crucial element situated just horizontally behind the sternum and protected by fat and fibrous tissue. It is important to release this trunk precautiously because injury at this level is difficult to suture and would require ligature (this is still possible if necessary but would lead to oedema of the left arm by defective drainage). After releasing the vein, the resection of the posterior wall of the sternum is completed with a Kerrison gouge. This gives a U-shaped groove that does not destabilise the sternoclavicular articulations and allows retraction of the vessels to expose the vertebral bodies. Screw fixation of T4 is possible, generally with slightly descending screws. The classical closure method is used.

Results: We have operated 13 patients with tumours or fractures using this approach (five T4, seven T3, one T2). Corporectomy was performed above T4. This approach did not lead to any direct complications. Postoperative pain was considered to be less than with sternotomy or cleidectomy, approaches we have now abandoned. Use of the endoscope improves visibility but the incision cannot be smaller because of the axe required for screwing. The important features of this method are the correct analysis of the preoperative relation between the target vertebra and the manubrium sternal and the dissection of the left brachiocephalic venous trunk.

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.