Intraoperative monitoring of somatosensory (SSEPs) and transcranial electric motor-evoked potentials (tce-MEPs) during surgical correction of neuromuscular scoliosis in patients with central or peripheral nervous system diseases.

PURPOSE: Combined intraoperative monitoring (IOM) of transcranial electric motor-evoked potentials (tce-MEPs) and somatosensory-evoked potentials (SSEPs) is safe and effective for spinal cord monitoring during scoliosis surgery. However, the literature data regarding the reliability of spinal cord monitoring in patients with neuromuscular scoliosis are conflicting and need to be confirmed. METHODS: We reviewed IOM records of 40 consecutive patients with neuromuscular scoliosis related to central nervous system (CNS) (29 pts) or peripheral nervous system (PNS) (11 patients) diseases, who underwent posterior fusion with instrumentation surgery for spinal deformity. Multimodalitary IOM with SSEPs and tce-MEPs was performed. RESULTS: Spinal cord monitoring using at least one modality was attempted in 38/40 (95 %) patients. No false-negative results were present in either group, but a relatively high incidence of false-positive cases (4/29, 13.8 %) was noted in the CNS group. Two patients in the CNS group and one patient in the PNS group presented transient postoperative motor deficits (true positive), related to surgical manoeuvres in two cases and to malposition in the other one. CONCLUSIONS: Multimodalitary IOM is safe and effective to detect impending spinal cord and peripheral nerves dysfunction in neuromuscular scoliosis surgery. However, the interpretation of neurophysiological data may be challenging in such patients, and the rate of false-positive results is high when pre-operatory motor deficits are severe.

Less invasive surgery in idiopathic scoliosis: a case report.

BACKGROUND: Minimally invasive spine surgery (MISS) has become popular during the last decade due to continuous evidence in favor of lesser soft tissue damage, faster recovery, higher patient satisfaction and reduced health costs. During the last years, surgical ambition for better results as well as most detailed knowledge of spinal anatomy, have resulted in the continuous and successful expansion of indications of MISS, covering already successfully a wide range of degenerative spinal pathologies as well as adult spinal deformities. AIM: We describe here a case report of a patient with adolescent idiopathic scoliosis (AIS) treated by minimally invasive posterior pedicle screw instrumentation. MATERIALS AND METHODS: We report the case of an 18 years old female patient affected by AIS, Lenke type 1AN, with a 65 degree right thoracic curve and severe rib hump. Posterior pedicle screw instrumentation as well as corrective manoeuvres were performed exclusively by minimally invasive procedure, through three small midline skin incisions. RESULTS: We obtained a good clinical and radiographical correction of scoliosis, which was maintained during the follow-up period. We also observed a limited intra-operative blood loss, a limited operative time, limited pain, earlier mobilization and limited hospital stay. CONCLUSIONS: A minimally invasive technique can be used for the surgical treatment of AIS, showing satisfying deformity correction and multiple perceived advantages, although long-term data are needed before this kind of surgery can be recommended for routine use.

Surgical treatment of neuromuscular scoliosis: current techniques.

41 consecutive patients surgically treated at Our Department by posterior only instrumented fusion from January 1995 to January 2009 were reviewed. There were 20 females and 21 males with a mean age of 15.8 years (range, 10 to 38). Diagnosis was: cerebral palsy (13 cases), Duchenne muscular dystrophy (7), spinal amyotrophy (7), myelomeningocele (5), poliomyelitis (3), Friedreich's ataxia (2), Escobar syndrome (2), Steinert's disease (1), Charcot Marie Tooth disease (1). Main scoliosis Cobb angle averaged 94.05° (range, 34° to 165°), the curve was thoracic in 19 cases, thoracolumbar or lumbar in 22 cases. Kyphosis (T5-T12) averaged 42.86° (range, 7° to 90°), lordosis was 33.57°. The fusion was extended to the lumbar tract in 23 patients, to the sacrum in the other 18. Our results showed that, in patients with neuromuscular scoliosis, posterior instrumented fusion is a safe and effective procedure and is the treatment of choice for patients with limited respiratory function, as in Duchenne muscular dystrophy and spinal muscular atrophy. The surgery should be performed as early as possible, and the extension of the fusion to the sacrum should be avoided in patients with residual walking ability.

Surgical treatment for scoliosis associated with rare disease.

This is a retrospective study of 11 patients, 7 females and 4 males, treated at Our Department for an early onset scoliosis (EOS) associated with rare syndromes with growing spinal implants (Growing Rod or VEPTR-like) from 2006 to 2011. Mean follow-up was 24 months (range, 12 to 36). The mean age at surgery was 7. Patients were affected by Escobar's syndrome (1), scoliosis associated to congenital heart disease (1), Arnold Chiari type 1 (1), syringomyelia (1), NF 1 (2), Prader-Willi syndrome (1), trisomy 8 (1), arthrogryposis (2) and spondylo-rib dysplasia (1). Each patient was studied from the genetic point of view, and were performed: brain-spine MRI, pulmonary function tests, Cardio-US and abdominal US, neuropsychiatric and neurological evaluation, C0-C2 CT scan. After first implant and lengthening procedures (11), the correction of the thoracic curve averaged 50%. Unfortunately, a little loss of correction of the lumbar curve occurred during the follow up. There were 8 post-operative complications, that required revision surgery in 2 cases. Our results confirmed the effectiveness and safety of growing spinal implants in the treatment of early-onset scoliosis in rare syndromes.

Complications incidence in the treatment of early onset scoliosis with growing spinal implants.

Early onset scoliosis (EOS) surgery based on growing spinal implants can lead to several complications. Aim of the study was to identify strategies to prevent those complications. A retrospective review was conducted to identify all pediatric patients affected by EOS surgically treated with growing rod or Vertical Expandable Prosthetic Titanium Rib (VEPTR) at our division between 2006 and 2011. Nineteen consecutive patients (8 males, 11 females; mean age 6.8 years) were included. The scoliosis was: idiopathic in 7 cases, congenital in 5, associated with congenital heart disease in 2, with syringomyelia and Arnold Chiari syndrome in 1, with neurofibromatosis type 1 (NF1) in 1, with Prader Willi syndrome in 1, with trisomy 8 in 1, with arthrogryposis in 1. Instrumentation used was: growing rod in 9 patients (dual rod construct in 8 cases, single rod in 1), VEPTR in 10 (always rib to spine construct). At a mean follow-up of 28 months (range, 12 to 55) 12 mechanical complications occurred in 8 of 19 patients treated (42.1%). Among cases treated with growing rod (9) 6 complications occurred in 4 patients (44.4%): revision was performed in 4 cases due to proximal anchors migration, in 2 cases due to a rod breakage. Among cases treated with VEPTR (10) 6 complications occurred in 4 patients (40%): revision was performed in 4 cases due to rib fracture with anchors migration, in 1 case due to vertebral anchor migration and in 1 case due to proximal and distal anchor migration. So, in our series mechanical complications rate was 42.1%. Our strategy to prevent these complications is to use hooks as proximal anchors, to avoid single rod construct and to use a brace as external support until final surgery is performed. If it's possible, is better to substitute VEPTR with a dual Growing Rod implant when patient's age and anatomy permits this.

The prevention of neural complications in the surgical treatment of scoliosis: the role of the neurophysiological intraoperative monitoring.

Iatrogenic spinal cord injury is the most feared complication of scoliosis surgery. The importance of combined somatosensory evoked potentials (SEP) and motor evoked potentials (MEP) monitoring during spine surgery is well known. The current authors retrospectively evaluated the results of neurophysiological intraoperative monitoring (IOM) in a large population of patients who underwent surgical treatment for spinal deformity. Intraoperative monitoring of SEPs and transcranial electrical stimulation MEPs (TES-MEP) was performed in 172 successive patients who underwent surgical treatment of idiopathic (128 pts), congenital (15 pts) or syndromic (29 pts) scoliosis. The first 106 patients (Group 1) underwent only SEP monitoring, while the other 66 patients (Group 2) underwent combined SEP and TES-MEP monitoring, when the technique was introduced in the current authors' institution. Halogenate anaesthesia (Sevoflurane, MAC 0.6-1.2) was performed in Group 1 cases, total intravenous anaesthesia (Propofol infusion, 6-10 mg/kg/h) in Group 2 patients. A neurophysiological "alert" was defined as a reduction in amplitude (unilateral or bilateral) of at least 50% for SEPs and of 65% for TES-MEPs compared with baseline. In Group 1, two patients (1.9%) developed postoperative neurologic deficits following surgical correction of spinal deformity, consisting of permanent paraparesis in one case and transient paraparesis secondary to spinal cord ischaemia in the other. Twelve patients presented intraoperative significant changes of neurophysiological parameters that improved following corrective actions by surgeons and anaesthesiologists, and did not show any postoperative neurologic deficits. In ten cases the alert was apparently unrelated to surgical manoeuvres or to pharmacological interventions and no postoperative neurologic deficits were noted. Considering the patients of Group 2, two patients (3.0%) presented transient postoperative neurologic deficits preceded by significant intraoperative changes in SEPs and TES-MEPs. In five cases a transient reduction in the amplitudes of SEPs (1 patient) and/or TES-MEPs (5 patients) was recorded intraoperatively with no postoperative neurologic deficits. In conclusion, in the current series of 172 patients the overall prevalence of postoperative neurologic deficit was 2.3% (4 patients). When combined SEP and TES-MEP monitoring was performed, the sensitivity and specificity of IOM for sensory-motor impairment was 100 and 98%, respectively. Combined SEP and TES-MEP monitoring must be regarded as the neurophysiological standard for intraoperative detection of emerging spinal cord injury during corrective spinal deformity surgery. Early detection affords the surgical team an opportunity to perform rapid intervention to prevent injury progression or possibly to reverse impending neurologic sequelae.

An innovative diagnostic procedure of vertebral deformities without exposure to X-rays.

The objective of the study was to compare standard manual X-ray measurements of vertebral deformities and values obtained from the Ortelius 800. 52 Patients (41 females and 11 males: mean age 20.35 years) with adolescent vertebral deformities, was studied. The patients were evaluated with standard radiographic views and the Ortelius 800. The parameters considered for the comparison were the angles of scoliosis and kyphosis and the values of global axial deformity, shoulder asymmetry and pelvic tilt. We also evaluated the modification of pelvic/shoulder angle after surgery (this parameter allows to evaluate vertebral rotation and can be derived only from the Ortelius 800). This study allowed us to conclude that there is a perfect agreement between measurements with the Ortelius 800 and those resulting from standard x-rays. The system has also proved to have the capability of quantifying changes in vertebral rotation.

Biological assessment of the bone-screw interface after insertion of uncoated and hydroxyapatite-coated pedicular screws in the osteopenic sheep.

The sheep seems to be a promising model of osteoporosis and biomaterial osteointegration in osteopenic bone. The long-term ovariectomized sheep model was used for the biological investigation of bone healing around uncoated and hydroxyapatite (HA)-coated pedicle screws in osteopenic bone. Four sheep were ovariectomized and four sheep were sham-operated. Twenty-four months after surgery, the animals were implanted with uncoated and HA-coated stainless steel screws in the lumbar vertebral pedicles. Four months later, bone-to-implant contact, bone ingrowth, and bone hardness were measured around screws. Uncoated stainless steel presented significantly (p < 0.0005) lower bone-to-implant contact in healthy and osteopenic bone compared with HA-coated stainless steel. HA significantly improved bone ingrowth in healthy bone (p < 0.05) compared with uncoated stainless steel. Osteopenia significantly (p < 0.05) reduced the area of bone ingrowth around the screw threads for both types of implants. In the inner thread area, bone microhardness significantly increased (p < 0.05) in HA-coated surface versus uncoated for healthy and osteopenic bone. HA coating significantly enhances bone-to-implant contact also in osteopenic bone in comparison with uncoated stainless steel surfaces. Bone ingrowth and mineralization are ameliorated by the osteoconductive HA coating. However, osteopenia seems to greatly influence bone ingrowth processes around the implanted screws regardless of the characteristics of the material surface.

Osteorticular amyloidosis in a patient under dialysis treated by total hip arthroplasty: case report and review of the literature.

The authors present the case of a patient affected by kidney failure, who had been undergoing dialysis for several years when areas of osteolysis and bone resorption in the proximal femur and pathologic fracture appeared. She was treated surgically by hybrid total hip arthroplasty. The patient also complained of pains in other joints. The bone tissue taken from the osteolytic area was examined histologically. The test showed the presence of an amyloid substance. Microradiography and X-ray diffractometry carried out on the same samples confirmed the lack of mineralisation due to the presence of aluminum ions, presumably derived from dialysis. The high concentration of this element was confirmed by resum assay with spectrophometry in atomic absorption. Considering the results of the aforementioned tests, the patient was put on dialysis using a polymethylmethacrylate filter.

Lumbar disc excision in children and adolescents.

STUDY DESIGN: The authors examined a case series of patients under the age of 18 years treated for lumbar intervertebral disc herniation. OBJECTIVES: To evaluate postoperative and long-term results of surgery in patients younger than 18 years. SUMMARY OF BACKGROUND DATA: There are only a few series, with controversial results, available on the surgical treatment of disc herniation in growing patients. METHODS: Between 1975 and 1991, a consecutive series of 129 patients 9-18 years of age (average age, 16.2 years) underwent surgery for lumbar intervertebral disc herniation. Low back pain associated with leg pain was the main clinical symptom in 106 subjects (82%), back pain in 17 (13%), and leg pain in 6 (5%). RESULTS: Short-term results were excellent or good for 123 cases (95%), with complete pain relief in 97 (75%) and moderate but incomplete relief in 26 (20%). A total of 98 (76%) long-term responses obtained at a mean follow-up of 12.4 years revealed excellent outcomes in 40% of the cases, good in 47%, and poor in 13%. Ten patients (10%) underwent reintervention after 9 years on average (2 fusions and 8 re-explorations for herniated disc). CONCLUSIONS: Results have confirmed a tendency for outcomes to deteriorate between the short-term and long-term follow-up in young patients treated by discectomy: this tendency and the rate of reintervention (10%) confirmed the need for long-term follow-up of children and adolescents treated for disc herniation.

Circumferential fusion by posterior approach in lumbosacral instability with or without pedicle screw fixation: a comparison of methods.

Lumbosacral circumferential fusion, a method which is widely adopted for the treatment of the different causes of lumbar pain, may be carried out in a single stage by posterior approach, associating interbody fusion with cages with posterolateral fusion. During the same operation, pedicle screw fixation may also be performed. In order to evaluate the need for this final surgical stage represented by pedicle screws, a comparison was conducted in 2 groups of patients affected with lumbosacral instability, treated at the Division of Vertebral Surgery at the Rizzoli Orthopaedic Institute between May 1995 and May 1997. The best clinical results were obtained in the first group (where pedicle fixation was associated). Because of the persistance of pain symptoms, successive pedicle fixation was instead required in a high percentage of patients (45%) in the second group (without pedicle fixation).

Lumbar disc herniation in the elderly patient.

It was the purpose of this study to clinically follow-up 78 patients affected with lumbar disc herniation, aged from 60 to 81 years (mean 66 years), hospitalized in several wards at the Rizzoli Orthopaedic Hospital between 1987 and 1996, for surgical treatment. A minimum of 24 months after surgery (maximum 61 months), sciatic pain (present in all of the patients prior to surgery) had regressed in 90% of the patients and was reported to occur only occasionally in 10%. Low back lumbar pain was still present in 21%. Results concerning recovery of motor deficit (30%), deficit in reflexes (31%), and sensory deficit (24%) were good. Better results were obtained when the surgical findings were sequestered hernia and expulsed hernia, with excellent results observed in 70% and 60%, respectively (based on the Smiley-Webster scale), as compared to contained hernia, the results for which were excellent in 54% of patients. Complications were observed in 9 cases (11%); 5 of the cases (6%) after a period of time ranging from 20 to 45 days postsurgery required further surgery because of an error in level in 3 and a residual nerve root compression in 2.

Intra-operative spinal cord monitoring in orthopaedics.

The surgical correction of spinal deformities carries a small but significant risk of injury to the spinal cord. To detect the onset and possibly reverse the effects of surgical complication, a variety of neurophysiological monitoring procedures can be employed. The purpose of this review is to provide information regarding the various methodologies available for monitoring spinal cord and nerve root function during orthopaedic procedures. Intra-operative monitoring of cortically recorded somatosensory evoked potentials (SEPs) by peripheral nerve stimulation is of value during orthopaedic surgery and is the state-of-the-art in terms of non-invasiveness, versatility, time requirement, lateral discrimination, and ease of electrode placement. Monitoring of motor evoked potentials (MEPs) is useful particularly in combination with SEPs but is still considered investigational. Root function monitoring has limited application and requires more clinical research.

Surgical correction of dystrophic spinal curves in neurofibromatosis. A review of 56 patients.

STUDY DESIGN: A presentation of the results from 56 patients with dystrophic spinal deformities caused by neurofibromatosis surgically managed from 1971 to 1992. OBJECTIVES: To focus on the need for combined anterior and posterior fusion in the presence of severe spinal dystrophic changes. SUMMARY OF BACKGROUND DATA: It has been stated that the most effective management for dystrophic curves is early and aggressive surgery. METHODS: The patients were divided into two groups: Type I scoliosis (kyphosis < 50 degrees) and Type II kyphoscoliosis (kyphosis > 50 degrees). Results were evaluated in relation to the type of surgery performed: single posterior instrumented fusion or preplanned combined anterior and posterior fusion. RESULTS: At a mean follow-up period of 15 years (range, 5-22 years), all patients appeared to be stabilized, after a total of 120 surgical interventions. In Group I, the posterior instrumented fusion failed in nine patients (47%), and in Group II it failed in seven patients (63%). The preplanned combined anterior and posterior fusion failed in two patients (33%) in Group I and in four patients (20%) in Group II. The failure incidence of the posterior instrumented fusion alone and of the planned anterior and posterior fusion was 53% (16 patients) and 23% (6 patients), respectively. CONCLUSIONS: The severe dystrophic curve with anterior vertebral scalloping always requires combined anterior and posterior stabilization, particularly in younger patients, even if the sagittal curves have not become pathologic by the time of presentation.

Posterior surgery for the treatment of thoracolumbar pathologic fractures in metastatic patients.

A total of 25 pathologic fractures in patients affected with thoracolumbar vertebral metastases associated with neurologic deficit are reported. None of the pathologic fractures were stable, while 14 were unstable and 11 were very unstable. Decompression with intralesional excision of the neoplastic mass compressing the dural sac was performed in all of the cases. Posterior stabilization was performed in the first cases using systems of sublaminar segmental fixation, and thereafter using systems of pedicle fixation. Removal of the vertebral body followed by anterior fusion after preventive posterior stabilization was performed in 2 cases. Pain symptoms regressed in 85% of the cases and in more than 50% of the patients there was improvement in the neurologic findings and in vertebral deformity consequent to fracture. Mean survival rate was 12 months. Despite the limited number of cases posterior stabilization of pathological fractures is a good choice of treatment in patients with severe neurologic deficit.

Diastematomyelia in congenital scoliosis. A review of the literature and description of one clinical case.

The authors present a case of diastematomyelia, a malformation of the neurospinal axis, frequently associated with congenital vertebral deformities. Often asymptomatic, its site different from that of the vertebral deformity, it may go unrecognized if specific imaging diagnosis is not used, thus exposing the patient who is then submitted to surgery for the correction of vertebral deformity to a high risk of neurological complications.

The surgical treatment of vertebral deformities in achondroplastic dwarfism.

The authors analyzed 15 patients affected with achondroplastic dwarfism with vertebral deformity treated surgically between 1976 and 1994. The forms represented were: achondroplasia; diastrophic dwarfism; spondyloepiphyseal achondroplasia. The types of vertebral deformity were: kyphosis: 12 (angular: 6; regular: 6); scoliosis: 1; kyphoscoliosis: 2. Neurological symptoms were present in 10 patients. Treatment was as follows: laminectomy: 8; posterior fusion with instrumentation: 2; anterior fusion: 2; anterior fusion with laminectomy and posterior fusion: 3. There were postoperative neurological complications in 4 cases (27%). Fusion must be performed early in angular kyphosis in the adult in order to prevent neurological symptoms. Wide laminectomies do not require associated fusion because they do not cause late vertebral instability.

Intraoperative ultrasonography imaging in spinal surgery (technique and indications).

Intraoperative ultrasonography was conducted in 20 patients; the technique of intraoperative ultrasonography for use in spinal surgery is described. The authors emphasize that this non-invasive method obtains real time images of considerable diagnostic importance, allowing for a significantly minor use of image intensifier, with a consequent reduction in doses for both the patient and the staff.

Anatomical ceramic arthroplasty (AN.C.A.): preliminary experience with a new cementless prosthesis.

The study reports the results obtained in 100 hips operated with a new cementless arthroplasty (AN.C.A.) characterized by the anatomical shape of a stem coated with Al2O3 and by a spherical acetabulum in ceramic-titanium, stabilized to the acetabulum first by screwing of the titanium ring and then by bony ingrowth in the cupola covered with porous ceramic. The patients were followed-up after an average of 17.4 months (+/- 8 SD). The patients were clinically evaluated using on the Merle d'Aubigné system, with the following average values +/- SD: pain 5.51 +/- 1, walking 5.01 +/- 1.1, and range of motion 5.38 +/- 0.9. The radiographic stabilization of the prosthesis (considering the worst results of the acetabulum and/or of the stem) was bony (BS) in 83% of the case and fibrous (FS) in 11%; 6 cases (5 acetabulums and 1 stem) showed signs of radiographic instability. Of these, 2 were submitted to further surgery to substitute the acetabulum. Two other patients were also submitted to a second operation: 1 involved substitution of the fractured ceramic head, and the other involved substitution of the stem in a patient with progressive coxalgia and no radiographic signs of loosening. The method of radiographic evaluation was significantly correlated with pain (p = 0.0001) and with walking (p = 0.0095). Instead, there were no significant correlations between stabilization of the prosthesis and precision of the femoral fit (press-fit) of the stem, age, evaluation of preoperative mineralization of the bone, and length of the stem. 8% of the cases presented important radiographic signs of stress-shielding; while 16% presented hypertrophy of the femoral cortex. These radiographic findings were not correlated to clinical ones.

Intramuscular hemangioma in infancy: diagnostic and therapeutic considerations.

Two cases of intramuscular hemangioma occurring in infancy are reported. These lesions require skillful preoperative evaluation, as they must be differentiated from soft tissue malignancies. If possible, surgical treatment should be delayed to a later age.