RESUMEN
OBJECTIVE There has been a transition from long- to short-segment instrumentation for unstable burst fractures to preserve motion segments. Circumferential fixation allows a stable short-segment construct, but the associated morbidity and complications are high. Posterior short-segment fixation spanning one level above and below the fractured vertebra has led to clinical failures. Augmentation of this method by including the fractured level in the posterior instrumentation has given promising clinical results. The purpose of this study is to compare the biomechanical stability of short-segment posterior fixation including the fractured level (SSPI) to circumferential fixation in thoracolumbar burst fractures. METHODS An unstable burst fracture was created in 10 fresh-frozen bovine thoracolumbar spine specimens, which were grouped into a Group A and a Group B. Group A specimens were instrumented with SSPI and Group B with circumferential fixation. Biomechanical characteristics including range of motion (ROM) and load-displacement curves were recorded for the intact and instrumented specimens using Universal Testing Device and stereophotogrammetry. RESULTS In Group A, ROM in flexion, extension, lateral flexion, and axial rotation was reduced by 46.9%, 52%, 49.3%, and 45.5%, respectively, compared with 58.1%, 46.5%, 66.6%, and 32.6% in Group B. Stiffness of the construct was increased by 77.8%, 59.8%, 67.8%, and 258.9% in flexion, extension, lateral flexion, and axial rotation, respectively, in Group A compared with 80.6%, 56.1%, 82.6%, and 121.2% in Group B; no statistical difference between the two groups was observed. CONCLUSIONS SSPI has comparable stiffness to that of circumferential fixation.
Asunto(s)
Fijación Interna de Fracturas/métodos , Vértebras Lumbares/cirugía , Fracturas de la Columna Vertebral/cirugía , Animales , Fenómenos Biomecánicos , Bovinos , Imagenología Tridimensional , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/fisiopatología , Movimiento (Física) , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fracturas de la Columna Vertebral/fisiopatología , Vértebras Torácicas/diagnóstico por imagen , Vértebras Torácicas/fisiopatología , Vértebras Torácicas/cirugía , Tomografía Computarizada por Rayos XRESUMEN
STUDY DESIGN: Calf spine model study. PURPOSE: To describe a technique of creating thoracolumbar burst fractures in calf spine model by low weight drop weight. OVERVIEW OF LITERATURE: Burst fractures are one of the commonest types of thoracolumbar fractures and their treatment is controversial. Biomechanical studies aid in the decision of treatment of these fractures. A simple method of creation of burst fractures would help these biomechanical studies. METHODS: Ten specimens of thoracolumbar spines harvested from 6-8 week old calves were weakened at the target vertebra by standardized osteotomy cuts. Burst fractures were created by dropping a 5-kg of weight from a height of 1.2 m using an in-house device. An accelerometer attached to the weight measured the acceleration at the point of impact. RESULTS: Average weight and bone mineral density of the specimens was 390 g and 0.67 g/cm(2), respectively. Computed tomography scan analysis of the fractures revealed McCormack grade 2 and grade 3 fractures in 5 and 3 specimens, respectively, Dennis type 2B in 4, type 2A burst fractures in 5 specimens and fracture dislocation in 1 specimen, AO type A3.1.1 in 4 specimens, type A3.2.2 in 4 and type A3.3.3 in 2 specimens. Vertical laminar split fracture was seen in 6 specimens. Average acceleration and energy at impact was 9.04 m/sec and 54.24 Nm, respectively. CONCLUSIONS: We describe a technique to create thoracolumbar burst fractures in calf spine by a drop weight method using a device that is simple to operate and easy to construct. The method is consistent and produces fractures similar to those occurring naturally, and can be considered as an alternative method for creating burst fractures in biomechanical studies.
RESUMEN
STUDY DESIGN: Retrospective analysis of radiological images. PURPOSE: To determine the prevalence of lumbosacral transition vertebra (LSTV) and to study its significance with respect to clinically significant spinal symptoms, disc degeneration and herniation. OVERVIEW OF LITERATURE: LSTV is the most common congenital anomaly of the lumbosacral spine. The prevalence has been debated to vary between 7% and 30%, and its relationship to back pain, disc degeneration and herniation has also not been established. METHODS: The study involved examining the radiological images of 3 groups of patients. Group A consisted of kidney urinary bladder (KUB) X-rays of patients attending urology outpatient clinic. Group B consisted of X-rays with or without magnetic resonance images (MRIs) of patients at-tending a spine outpatient clinic, and group C consisted of X-rays and MRI of patients who had undergone surgery for lumbar disc herniation. One thousand patients meeting the inclusion criteria were selected to be in each group. LSTV was classified by Castellvi's classification and disc degeneration was assessed by Pfirrmann's grading on MRI scans. RESULTS: The prevalence of LSTV among urology outpatients, spine outpatients and discectomy patients was 8.1%, 14%, and 16.9% respectively. LSTV patients showed a higher Pfirrmann's grade of degeneration of the last mobile disc. Results were found to be significant statistically. CONCLUSIONS: The prevalence of LSTV in spinal outpatients and discectomy patients was significantly higher as compared to those attending the urology outpatient clinic. There was a definite causal relationship between the transitional vertebra and the degeneration of the disc immediately cephalad to it.
RESUMEN
Osteochondromas are the most common benign tumors of the bone. They mostly arise from the appendicular skeleton and present clinically in the second or third decade of life. Ostechondromas arising from the subaxial cervical spine and presenting after the 5th decade of life are extremely rare. We report a 52-year-old male patient who presented with numbness and subjective weakness of left upper and lower limbs and neck pain, and had lobulated bony hard fixed swelling in the right lower cervical paraspinal region. Radiological images revealed a bony swelling arising from C4 and C5 lamina with a cartilaginous cap and intraspinal extension. Excision biopsy with stabilisation of the spine was performed. Histopathalogical examination of the specimen confirmed the diagnosis of osteochondroma. We conclude surgical excision of such rare tumors, including the cartilaginous cap as well as the intraspinal component can reliably produce a good clinical outcome.
RESUMEN
Gorham's disease is a rare disorder characterized by clinical and radiological disappearance of bone by proliferation of non-neoplastic vascular tissue. The disease was first reported by Jackson in 1838 in a boneless arm. The disease was then described in detail in 1955 by Gorham and Stout. Since then, about 200 cases have been reported in the literature, with only about 28 cases involving the spine. We report 2 cases of Gorham's disease involving the spine and review related literature to gain more understanding about this rare disease.
RESUMEN
Pseudomeningocele is an extradural cerebrospinal fluid collection arising from a dural defect, that may be congenital, traumatic, or more commonly as a result of postoperative complication. Majority of the postoperative pseudomeningoceles occurring after lumbar spine surgeries are small and resolve spontaneously. However, large pseudomeningoceles are rare and spontaneous resolution of such pseudomeningoceles has not been described. We report four cases of postoperative large lumbar pseudomeningoceles that presented as asymptomatic soft fluctuant swelling over the back which resolved spontaneously. We also reviewed the related literatures and operative records of these patients to find the possible mechanism of occurrence, their management, prevention, and reasons for spontaneous resolution. We conclude that nonoperative management under close observation can be employed for asymptomatic postoperative large lumbar pseudomeningoceles. Surgical exploration and repair should be reserved for symptomatic cases presenting with clinical features of intracranial hypotension, worsening neurology, external fistula or infection, thereby avoiding morbidity and potential complications associated with surgical treatment.
RESUMEN
INTRODUCTION: A series of 12 patients in our centre following single level instrumented posterior lumbar interbody fusion at L4-L5 developed unexplainable motor weakness in the proximal lumbar nerve roots (L2, L3) and numbness of the whole limb, a clinical picture resembling lumbar plexopathy. Even though lumbar plexopathy has been reported following gynaecological procedures and in transpsoas interbody fusion surgeries, there is no literature reporting this complication following conventional instrumented posterior lumbar interbody fusions. STUDY DESIGN: Retrospective observational study. OBJECTIVE: To find the possible mechanism of development of lumbar plexopathy in patients who underwent posterior lumbar interbody fusion surgeries in our centre. MATERIAL AND METHODS: We analyzed retrospectively the medical records, electrophysiological reports of the patients, literatures on the anatomy of lumbar plexus and other literature reporting similar complications. We also dissected lumbar plexus of three cadavers and simulated surgical technique on them to find the mechanism of development of this unusual complication. RESULTS: We found injury to lumbar plexus that probably occurred intraoperatively with Hohmann's retractor that was used for retraction of the paraspinal muscles. This theory was favoured by many clinical factors and further confirmed by cadaveric dissections. CONCLUSION: We conclude that surgical technique with improper use of Hohmann's retractor causes traction and compression injury to the lumbar plexus resulting in this complication. We propose proper technique of insertion of Hohmann's retractor and also recommend use of modified Hohmann's retractor with shorter tips for spinal procedures to prevent such complication.