Delayed-iatrogenic injury of the thoracic aorta by an anterior spinal instrumentation.

We present a case of a 15-year-old girl who presented to us with an unusual low back pain. About 7 years ago, this patient had corrective surgery for her idiopathic left thoracolumbar scoliosis. Recent surgery revealed a laceration of the posterior wall of the thoracic aorta by an impending screw thread. This injury was repaired by the vascular surgeons and, subsequently, the patient had full recovery without any complications.

Resection arthrodesis of the ankle for aggressive tumors of the distal tibia in children.

BACKGROUND: There is no consensus on the ideal treatment for malignant tumors of the distal tibia. Many favor amputation. METHODS: Thirteen children, at an average age of 12 years (8 to 16 y) sustained conservative surgical treatment for a tumor of the distal tibia. All patients had "en bloc" resection of the tumor with ankle arthrodesis achieved by nail or plate accompanied by autograft. RESULTS: The results were assessed retrospectively with an average follow-up of 8.8 years. Nine patients were in complete remission. Two patients had died. Two patients were lost to follow-up. Two patients had a local recurrence, which required amputation. There were 4 infections, which responded well to therapy. Four patients required additional bone grafting because of nonunion. Three patients required osteotomy for malalignment. Bone healing was achieved for the 9 patients seen at last follow-up. All were able to walk with an average functional score of 24.7/30 (23 to 26) on the Musculoskeletal Tumor Society score. CONCLUSIONS: Several reconstructive techniques are available: mega prosthesis of distal tibia and ankle, reconstruction by vascularized fibula or by autograft. All series reported significant rates of infections, cutaneous necrosis, and nonunion. DISCUSSION: Conservative treatment with ankle arthrodesis is a possible alternative to amputation for the management of malignant tumors of the distal tibia in selected patients. Survival results and functional outcome were good despite initial complications. LEVEL OF EVIDENCE: This is a retrospectively therapeutic study graded level 2 as level of evidence.

Analysis of the mechanisms of idiopathic scoliosis progression using finite element simulation.

The mechanisms of idiopathic scoliosis progression are still not fully understood. The aim of this study is to explore, using finite element simulation, effect of the combination of gravity and anterior spinal overgrowth on scoliosis progression. 14 adolescents (10 girls, 4 boys) with an average age of 10.8 years [range 9; 13] were divided in three groups: thoraco-lumbar scoliosis (TL), lumbar scoliosis (L), asymptomatic patients (A). Accurate 3D reconstructions of the spine have been built using bi-planar X-rays. A patient specific validated finite element model has been used. Simulations have been launched with simulation of the combined effect of gravity and growth. The progression during the simulation was defined by a maximal axial rotation movement greater or equal than 4 degrees and a maximal lateral displacement greater or equal than 5 mm ("first order progression" for one criterion, "second order" for the both criteria). In the group TL, we notice an aggravation for 4 patients (Cobb angle increase at least by 4 degrees , mean at 5.9 degrees ). Only three patients of the group L show a progression with a smaller Cobb angle increase (mean 3.9 degrees ). For the group A, no progression is found for 3 and a progression is found for 1. An anterior spinal overgrowth combined with gravity and a pre-existent curve in the spine could lead to a progression of scoliosis. It seems necessary to consider differently lumbar curves from other curves. Numerical simulation with a patient specific model appears as a useful tool to investigate mechanisms of scoliosis aggravation.

[Surgical treatment of stiff massive knee endoprosthesis for bone tumors in children and adolescents]. / Traitement chirurgical de la raideur après prothèse massive du genou pour tumeur osseuse chez l'enfant et l'adolescent.

PURPOSE OF THE STUDY: Improved oncologic outcome and technical advances in limb salvage surgery have made limb salvage therapy a feasible and valuable treatment option. Nevertheless, resection of a bone tumor followed by a reconstruction knee endoprosthesis can create gait abnormalities, of which one of the most frequent is knee stiffness. The aim of this retrospective study was to assess the outcomes of revision surgery for a stiff knee following reconstruction of a segmental long bone defect. PATIENTS AND METHODS: Between 1983 and 2005, 19 patients who had undergone wide resection of a tumor close to the knee followed by reconstruction with a massive endoprosthesis were revised for a diagnosis of stiffness. RESULTS: The mean age of the patients was 12 years (range: 7-19 years). Patients were followed for a mean five years (range: 1-21 years). Three patients were not assessed at the last follow up (two patients died, one patient was amputated for a local recurrence). The mean range of motion improved 80+/-24 degrees preoperatively to postoperatively. The Enneking score improved from 15+/-0.5 to 23+/-3 points at three months follow-up, and to 22+/-5 at last follow-up. Recurrent stiffness occurred three times and required a second operative release with a good final result. DISCUSSION: Outcome depends on the cause of the stiffness of the reconstruction knee arthroplasty. Stiffness can be caused by complications (trauma, implant failure, infection), and patient-related factors (lack of physiotherapy). Open arthrolysis is indicated for chronic stiffness in a motivated patient with an identified cause because failure to identify the cause of stiffness may result in recurrence of the problem.

[Orthopedic treatment of spinal deformities in infancy and early childhood]. / Le traitement orthopédique dans la pathologie vertébrale du petit enfant.

Surgical treatment of spinal deformities in infancy and early childhood (before age 6) is often very useful if the lesion is localized and curable by one unique surgery, such as hemivertebra resection and fusion. On the contrary, if the lesion, whether idiopathic or paralytic, is extended to a large part of the spine, early surgical treatment in infancy gives very disappointing results and often worsens the status of the child, especially respiratory function if the lesion is mainly thoracic. The goal of this paper is to explain in detail indications and management of non-surgical treatment of such lesions. These are variable according to localization, etiology, and associated anomalies, and are mainly based on proper casting (often repeated), bracing (often intermittent between casting) and proper respiratory equipment. From time to time, a surgical treatment is locally indicated, but most of the time results are disappointing and the best is to repeat non-surgical treatment until proper definitive arthrodesis can be performed. This approach is not very rewarding for the child and family, but is clearly better than sudden extensive surgery in early childhood with very severe and disastrous results in adulthood. It is our hope that the recommendations and thoughts presented in this paper will help readers to manage young children using the most efficient, non-aggressive, but long-lasting therapy.

No benefit of ifosfamide in Ewing's sarcoma: a nonrandomized study of the French Society of Pediatric Oncology.

PURPOSE: To undertake a new protocol with the goals of improving the chemotherapeutic treatment of pediatric Ewing's sarcoma by introducing ifosfamide, and to widen the indications for surgical resection of Ewing's tumor to obtain better local control and to reduce radiation doses. PATIENTS AND METHODS: The French Society of Pediatric Oncology initiated its first cooperative Ewing's sarcoma study in 1978, using a four-drug regimen (cyclophosphamide, dactinomycin, Adriamycin [doxorubicin; Farmitalia Carlo Erba, Rueil-Malmaison, France], and vincristine). Ninety-five patients were included, and, at 5 years, the disease-free survival reached a plateau of 51%. After encouraging responses of recurrent soft tissue or bone sarcomas to ifosfamide, a second study began in 1984 using a new chemotherapy regimen in which cyclophosphamide was replaced by ifosfamide. Sixty-five patients were treated. RESULTS: By February 1992, the median follow-up was 5.8 years. The estimated 5-year disease-free survival was 52%. We observed unexpected cardiac toxicity. Three patients experienced acute cardiac failure that was lethal in two cases. The acute toxicity of ifosfamide prompted us to stop the protocol. Retrospectively, the lack of efficacy reinforced our decision. CONCLUSION: We conclude that ifosfamide did not improve the outcome of the patients despite the fact that these two treatment regimens were not randomized.

[Surgical treatment of lumbosacral spondylolisthesis with major displacement in children and adolescents: a continuous series of 20 patients with mean 5-year follow-up]. / Le traitement chirurgical du spondylolisthésis lombo-sacré à grand déplacement de l'enfant et de l'adolescent.

PURPOSE OF THE STUDY: This retrospective analysis involved a continuous series of twenty cases of lumbosacral spondylolisthesis with major displacement treated before maturity. We compared our experience using a non-instrumented lumbosacral fusion technique with the results of other techniques proposed in the literature. MATERIAL AND METHODS: We reviewed the cases of twenty children and adolescents who underwent surgery in our unit. For each case, we recorded the clinical history and course to last follow-up. X-rays were studied and manual measurements taken of the different parameters used to analyze the spine. Data were recorded in a database for statistical analysis. Sixteen of the twenty cases showed spinal deformation causing lumbalgia, generally associated with radiculalgia. Mean age at surgical treatment was 13 years 3 months, range 7 years 2 months to 17 years 6 months. All of the children has Meyerding stage 3 or 4 displacement associated with lumbosacral kyphosis. Surgical treatment followed a period of progressive reduction by traction and suspension in lordosis using a hammock. All twenty patients underwent posterolateral arthordesis using a cancellous graft between L4 and the sacrum. The fusion was performed after fashioning a thoraco-lumbo-pelvic cast including both thighs in the position of reduction. A complementary time for anterior arthodesis was needed for eight patients. RESULTS: The postoperative period was uneventful in twelve patients. Two children developed intestinal obstruction with a peritoneal bridle. Three children had an L5 radicular deficit and three sphincter disorders. All neurological disorders resolved in a few months. At mean postoperative follow-up of 5 years 3 months, the arthrodesis appeared to be fused in 19/20 cases. Only one patient presented a lucent line in the zone of the bone graft suggesting possible fibrous nonunion. Eighteen patients were symptom free and led a normal life. Two patients complained of moderately bothersome lower back pain. DISCUSSION: Many of the children in our series had major lumbosacral dysplasia with a verticalized sacrum, aggravating the lumbosacral kyphosis. This led to an increased pelvic tilt and decreased sacral slope. Progressive preoperative reduction of the lumbosacral kyphosis allowed conducting the lumbosacral fusion under favorable conditions. We did not open the spinal canal and avoided the mid line in order to protect as much as possible posterior spinal stability and preserve all the bone surfaces receiving the posterolateral graft. We reserved indications for complementary anterior lumbosacral arthrodesis to the most exaggerated cases of lumbosacral kyphosis. The therapeutic program is long due to the progressive preoperative reduction and the strict period of immobilization after surgery. In our experience, this approach allows quality lumbosacral fusion with good correction of the lumbosacral kyphosis. Neurological complications remain frequent and can occur during even slow progressive reduction.

Non-metastatic Ewing's sarcoma of the ribs: the French Society of Pediatric Oncology Experience.

From 1984 to 1997, 57 consecutive patients with non-metastatic Ewing's sarcoma of the ribs were treated according to multimodal French Society of Pediatric Oncology (SFOP) protocols EW 84, EW 88 and EW 93. The results of treatment were reviewed and analysed. Median age was 12 years. 34 patients had large tumours (greatest tumour dimension > or = 8 cm); pleural effusion was noted in 26. A tumour-positive margin after surgery was noted in 15 patients. Histological response after chemotherapy was assessed in 34 patients. 34 patients received radiation therapy. With a median follow-up of 5 years, the projected overall and relapse-free survival rates were 69 and 62%, respectively. The major site of relapse was local. None of the following was significant in predicting relapse: tumour size, gender, age at diagnosis, existence of pleural effusion, level of rib tumour, rib component, type of local control, surgical margin (positive or negative). Response to chemotherapy was the sole significant prognostic factor (P=0.004). Patients with pleural effusion had a higher percentage of relapse if they were treated without local radiation therapy. Our study confirms the prognostic significance of response to initial chemotherapy. Radiation therapy may be withheld in selected cases, but seems necessary in patients with pleural effusion.

Torticollis in children caused by congenital anomalies of the atlas.

Hemi-atlas is a rare congenital anomaly in the formation of the first cervical vertebra. It may cause a rather severe and progressive torticollis. When a child is young, the neck, despite the deformity, is flexible and the torticollis can be passively corrected. However, in some patients it becomes increasingly severe and fixed. I describe the findings in seventeen patients, seven of whom were operated on between 1975 and 1983. Treatment with a brace was shown to be ineffective. In patients with severe deformities, fusion of the upper part of the cervical spine is recommended. Fusion was obtained in all seven patients in whom it was attempted, and there was good postural correction in all. Early operation is recommended if the deformity is increasing. Gradual correction in a halo cast followed by posterior fusion is recommended as the treatment of choice in patients with severe torticollis.

Explicit calibration method and specific device designed for stereoradiography.

The three-dimensional geometry of the human spine is noteworthy information that can be obtained by stereoradiographic methods. These methods are based on the identification of anatomical structures in several views which are obtained by rotation of a patient standing on a turntable. Calibration algorithms for computer vision or photogrammetry are well documented, but they generally yield calibration devices which are cumbersome for the use in clinical stereoradiography. This paper presents a calibration method adapted to a two-view stereoradiography calibration (frontal and lateral incidences) and based on a simplified geometric modeling of the radiological environment. The a priori knowledge yields four calibration equations related to the vertical and horizontal planes of both views, leading to a specific calibration procedure and device. Moreover this device is attached to the stereoradiographic system (directly integrated on the turntable) in order to facilitate clinical applications. A validation was performed on 26 dried lumbar vertebrae in order to evaluate clinical situation. The mean accuracy of the stereoradiographic reconstruction was 1.2mm.

Progressive rotational dislocation in kyphoscoliotic deformities: presentation and treatment.

STUDY DESIGN: Progressive rotational dislocation of the spine has been described as the most serious evolutive risk of kyphoscoliosis. A retrospective chart review was conducted on 11 patients with this deformity. OBJECTIVES: To delineate the clinical and radiologic characteristics of this entity to facilitate early diagnosis and treatment. The outcome after treatment was analyzed to point out the rationale for appropriate treatment. METHODS: The characteristic radiologic feature was a short sharp angled kyphosis (average 112) at the junction of two lordoscoliotic curvatures. The etiology of the spinal deformity was neurofibromatosis in four patients and various dysplastic conditions in seven patients. Two patients had congenital vertebral defects. Structural weakness of the bone was therefore a basic feature. Neurologic impairment was identified in three patients (one complete, two incomplete). Four patients had a nonunion after a previous attempt at spinal fusion: two after a combined anterior and posterior fusion with an anterior approach from the convexity and two after a posterior fusion alone. All patients underwent complete circumferential stabilization through anterior strut-grafting and posterior fusion. An anterior approach from the concavity was performed systematically with tibial strut grafts inserted in a palisade fashion. Preoperative correction of the deformity was performed by progressive controlled elongation in a Stagnara elongation cast. Cotrel-Dubousset instrumentation was used in two patients, Harrington instrumentation was used in two patients, and cast immobilization alone was used in seven patients. RESULTS: The average follow-up period was 5 years 5 months. All but one patient achieved successful spinal fusion. Loss of correction at the latest follow-up evaluation was less than 3 degrees in nine patients. The two patients with incomplete neurologic deficits were improved, but the patient with the complete deficit remained unchanged after surgery. CONCLUSIONS: Awareness of the possibility of a progressive rotational dislocation in dystrophic forms of kyphoscoliosis should allow for an early diagnosis and stabilization. The percentage of patients having a neurologic deficit in this series was significantly less important than in the initial report. Early anterior strut grafting from the concavity of the scoliotic curvature and posterior fusion is recommended.

Histiocytosis X in the juvenile spine.

The authors studied 54 lesions, caused by histiocytosis X, that affected the spines of 28 children. The clinical, radiologic, biologic, and therapeutic aspects are described. The orthopaedic surgeon has a role to play in confirming the diagnosis, treating the lesion, and in following up.

A biomechanical analysis of short segment spinal fixation using a three-dimensional geometric and mechanical model.

Vertebral stabilization using spinal fixation devices is a widely used technique. A three-dimensional geometric and mechanical finite element model has been used as a simulation tool for the evaluation of the mechanical behavior of spinal devices. The geometry of lumbar vertebrae was parameterized, which allows the construction of the geometric model for a given lumbar segment from the digitization of two roentgenographs. This procedure was used to construct a finite element model for a three-vertebra segment with simulation of fractures in the middle vertebra, and with simulation of a restoration using an osteosynthesis device, implemented in a frame fashion with four screws and two rods linked by two transverse rods, and/or an anterior bone graft. Compression force and torsion moment were considered, and different cases were investigated, by varying the severity of the fracture, the geometric characteristics of the device, and the mechanical characteristics of the material joining the two intact vertebral bodies. Results were analyzed considering the mobility of the vertebral segment, which indicates the ability of the restoration system to stabilize the vertebral segment, and considering the forces and moments distribution in the device, which gives information on part of the forces that pass through the device in each situation. Results show that maximum values of forces and moments in the device are more important in compression than in torsion. Adding an anterior bone graft has an effect mainly for compression, whereas in torsion its effect is negligible. For a rigid fixation device, no significant difference was found between different fracture models, indicating that the posterior arch does not play an important role for an instrumented segment. For compression, a rigid posterior wall, or the presence of a bone graft, reduces greatly the mobility of the instrumented segment. For torsion, suppressing the two transverse rods in the device greatly increases the mobility of the instrumented segment. Using a finite element model of a lumbar vertebral segment appears to be an interesting tool to analyze the behavior of an instrumented spine and to compare between different stabilization systems.

The congenital dislocated spine.

STUDY DESIGN: The congenital dislocated spine has been defined as the potentially most serious form of congenital kyphosis with an abrupt single-level displacement of the spinal canal. A retrospective chart review was conducted on 19 patients with this deformity. OBJECTIVES: To delineate the clinical and radiologic characteristics of this entity, and to analyze the outcome after treatment. SUMMARY OF BACKGROUND DATA: An anterior failure of formation was the basic feature. Kyphosis was variable. Vertebral displacement in the frontal plane was present in seven patients, and sagittal displacement was constant. Mechanical instability was seen in 17 patients. Neurologic impairment was identified in 12 patients, and congenital paraplegia was seen in eight patients. An acute paraplegia occurred after minor trauma in one patient. METHODS: Seventeen patients were treated surgically. Thirteen patients underwent complete circumferential stabilization through anterior strut grafting and posterior fusion without instrumentation, usually before age 3 years. Neurosurgical decompression was done in four patients. RESULTS: The average follow-up period was 8 years, 6 months. Nonunion of the posterior fusion mass was detected and successfully treated in five patients. A solid fusion seemed to be obtained in all patients at last follow-up evaluation. The neurologic status after neurosurgical decompression remained unchanged in three patients and was improved temporarily in one patient. CONCLUSIONS: Avoidance of neurologic morbidity requires early diagnosis and stabilization. The authors recommend early anterior strut grafting and posterior fusion. Exploration of the posterior fusion mass should be done systematically.

Operative treatment of scoliosis with Cotrel-Dubousset-Hopf instrumentation. New anterior spinal device.

STUDY DESIGN: This study analyzes the effects of a new anterior spinal instrumentation system and the results of use in 50 patients with scoliosis. OBJECTIVES: Anterior spine systems are reviewed. The principles of a new anterior spinal instrumentation system allowing for postoperative care without external support are discussed. SUMMARY OF BACKGROUND DATA: Numerous different implants have been presented in the literature for anterior spinal surgery. Nevertheless a primary stable anterior instrumentation was not available for multisegmental procedures until now, and the restoration of lordosis in the lumbar spine was very difficult with the common devices. The development of more stable devices that also allow a restoration of lordosis in combination with derotation and compression is discussed. METHODS: Fifty patients with scoliosis of different etiologies (neuromuscular: n = 33; idiopathic: n = 16; congenital: n = 1) underwent anterior spinal surgery at the thoracic, thoracolumbar, and lumbar spine. During follow-up, no revision operation was necessary after the monosegmental and multisegmental application of this method, and there were no vessel complications. The results were controlled with a mean follow-up of 26.6 (range 12-41) months. RESULTS: Clinical and radiologic follow-up and complications are reported. Statistical data obtained show a different average blood loss and operation time depending on the different etiology of the scoliotic deformity. The mean corrections for the scolioses by etiology are as follows: myelomeningocele (MMC) (mean preoperative angle 89 degrees, mean correction 54%); neuromuscular (81 degrees, 46%); and idiopathic (55 degrees, 69%). The mean lordosis of the lumbar spine was 29.2 degrees (measured between T12-S1) and could be corrected to 45.2 degrees depending on the etiology of the curvature, whereas the angle of the thoracic kyphosis did not show an essential change. The segmental measurement in idiopathic scoliosis did not show a kyphosization in the lumbar spine. Derotation of the apical vertebra in 15 patients in relation to the sagittal plane was 37%. CONCLUSIONS: The study shows the effect of a new anterior device allowing the application of three-dimensional correction forces to the spine. Particularly in scoliosis derotation, compression and restoration of lordosis are possible. Primary stability is obtained by anchoring the implants with a new wedge-locking technique, which makes postoperative external support unnecessary.

Characterization of bone forming cells in posttraumatic myositis ossificans by lectins.

Lectins were used to characterize bone forming cells in posttraumatic myositis ossificans. The lectins applied were as follows: Arachis hypogaea (PNA): specific for beta-D-galactose (1,3)N-acetyl-D-galactosamine (Gal-1,3 GalNac), Canavalia ensiformis (Con A): specific for alpha-D-glucose (D-Glc) and alpha-D-mannose (D-Man) and Wheat germ (WGA): specific for N-acetyl(1,4)D-glucosamine (Glc-NaC) and neuraminic acid. The development of myositis ossificans was characterized by the appearance of a WGA binding cell population. The lectin-binding sites appeared as a cluster in the supranuclear cytoplasm, corresponding to the Golgi-complex. However, the WGA lectin-binding sites disappeared in the mature form of myositis ossificans. We assume that these lectin binding cells may be the bone marrow derived precursors of myofibroblast-like cells which are responsible for bone formation within the damaged muscle.

Chiari I malformation associated with syringomyelia and scoliosis.

STUDY DESIGN: A retrospective review of a series of 12 children who underwent suboccipital foraminotomy and duroplasty for Chiari I malformation. OBJECTIVE: To assess the effects of this surgery on associated syringomyelia and scoliosis. SUMMARY OF BACKGROUND DATA: Suboccipital foraminotomy for the treatment of syringomyelia associated with Chiari I malformation was greatly stimulated by Gardner's hydrodynamic theory, and its results proved to be encouraging. However, several authors reported improvement or stabilization of associated scoliosis after this surgery. METHODS: A retrospective review was conducted on 12 patients who underwent suboccipital foraminotomy for Chiari I malformation associated with syringomyelia. Neurologic Impairment, extent of syringomyelia, and severity of associated spinal deformity were assessed preoperatively and at a 4.5-year average follow-up (range, 2.1-12 years). Anomaly of superficial abdominal reflexes was found in all cases, and para or tetraparesis in three cases. Syringomyelia was of variable localization and extent. Scoliosis was present in 7 cases (greater than 40 degrees in 5 cases). RESULTS: Diminution or complete disappearance of syringomyelia was observed in 11 cases, 3 months to 1 year after surgery. Superficial abdominal reflexes anomaly improved in four cases. Minimal neurologic deficit persisted in one case. Scoliosis improved in one case, remained unchanged in one case, and progressed in the five cases with preoperative severe deformity, requiring instrumentation and fusion. CONCLUSIONS: Improvement of syringomyelia and neurologic deficit, observed with suboccipital foraminotomy, supports the theory that abnormal hydrodynamics of the cerebral spinal fluid is most likely to cause these deficits.

Posterior spinal fusion in neuromuscular scoliosis using a tibial strut graft. Results of a long-term follow-up.

STUDY DESIGN: Risks and benefits of using a tibial graft for posterior spinal fusion in neuromuscular scoliosis were evaluated in a long-term follow-up study. A consecutive series of 72 patients underwent posterior spinal fusion for neuromuscular scoliosis. OBJECTIVES: Radiologic outcome was assessed to evaluate the quality of the spinal fusion. Patients were followed serially to detect donor site complications. Mean follow-up was 17 years and 8 months (minimum: 6 years, 6 months). SUMMARY OF BACKGROUND DATA: Mean age of the patients at the time of surgery was 15 years. Progression of the curvature was minimal at last follow-up (mean progression at last follow-up: lumbar curve, 4.5 degrees; thoracic curve, 5.3 degrees). Concerning donor site complications, four patients had a leg length discrepancy of less than 2 cm at last follow-up. This complication was related to tibial overgrowth at the donor site. METHODS: Solid fusion was defined in this long-term study as the absence of modification of the radiologic aspect at last follow-up in addition to the presence of a massive contagious trabecular fusion mass. RESULTS: The fusion appeared to be solid in all patients. No obvious pseudarthrosis could be documented. The constant successful outcome differs significantly from spinal fusion that uses bank bone. The absence of stress fracture was correlated to the low level of constraint in this essentially nonambulatory population. CONCLUSION: This experience indicates that the tibial graft deserves consideration in posterior spinal fusion for neuromuscular scoliosis.

An experimental study in chickens for the pathogenesis of idiopathic scoliosis.

Experimentally induced scoliosis was investigated in pinealectomized chickens using pathologic and neurophysiologic means. A total of 90 chickens were tested; 30 served as a normal control, 30 received an autografted pineal body in the intramuscular tissue of the trunk, and 30 underwent pinealectomy without autograft. Scoliosis developed in all pinealectomized chickens within 2 weeks, showing gradual progression during the next 5 or 6 weeks. At 3 months, the three-dimensional spinal deformity consisted of lateral curvature and vertebral body rotation, resulting in a prominent lordoscoliosis at the thoracic level. In contrast, scoliosis developed in only 10% of the autografted chickens. Histologic examination revealed no pathologic change in the brain in either the pinealectomized scoliosis group or in the autografted nonscoliosis group. Cortical potentials in the scoliosis group were delayed, thus suggesting conduction disturbance rostral to the brain stem. Although the relationship between the cause and effect is uncertain, these findings implicate neurotransmitters or neurohormonal systems in the pineal body as a major contributing factor in this type of experimental scoliosis.