Percutaneous Stenoscopic Lumbar Decompression with Paramedian Approach for Foraminal/Extraforaminal Lesions

The lumbar foramen is affected by different degenerative diseases, including extraforaminal disc herniation, foraminal stenosis (FS), and degenerative or spondylolytic spondylolisthesis. The purpose of this study was to describe percutaneous stenoscopic lumbar decompression with a paramedian approach (para-PSLD) for foraminal/extraforaminal lesions. All operative procedures were performed using a complete uniportal endoscopic instrument system. The para-PSLD can be easily applied to patients with FS and narrow disc space or facet joint hypertrophy. The anatomical view of a para-PSLD is similar to that of a conventional open surgery and allows for good visualization of the foraminal/extraforaminal areas. We suggest that para-PSLD is an alternative and minimally invasive procedure to treat degenerative lumbar foraminal/extraforaminal stenoses.

Placa infrapectínea para reparación con mínima invasión de fracturas de lámina cuadrilátera acetabular: descripción de un nuevo implante y acceso paramedial / Infrapectineal Plate for repair with minimal invasion of quadrilateral blade acetabular fractures: description new implant and paramedial access

Resumen: Introducción: Las fracturas de la lámina cuadrilátera del acetábulo son las más difíciles de reducir y fijar. Se han desarrollado diferentes técnicas para la osteosíntesis de la lámina cuadrilátera. El objetivo de este trabajo fue crear implantes y un nuevo acceso quirúrgico para simplificar y mejorar la osteosíntesis de fracturas del acetábulo. Material y métodos: Un total de 83 pacientes fueron estudiados mediante la tomografía axial computarizada de ambos acetábulos, siendo medidos a nivel de columna posterior alta y baja con el fin de determinar longitud y diámetro de los implantes, a través del análisis de normalidad de variables, dónde p es > 0.05, usando la prueba Kolmogorov-Smirnov (Lilliefors). Las características anatómicas del nuevo acceso quirúrgico también se describen. La incisión se practicó en espécimen cadavérico para determinar la seguridad de todo el acceso. Resultados: El par de tornillos macho-hembra midió 20 x 6 x 8 mm (longitud, diámetro interno y de la cabeza), mientras que las placas fueron de 10 mm de ancho y 3 mm de espesor, con longitud correspondiente al número de orificios. Se desarrollaron instrumentos apropiados para su aplicación. Discusión: Este método puede facilitar la osteosíntesis del acetábulo. Se requieren estudios cadavéricos y clínicos para corroborarlo. Puede ser que se mejoren los resultados de osteosíntesis del acetábulo, con menor riesgo.

Abstract: Introduction: Quadrilateral plate fractures are the most difficult to reduce and fix. Different techniques have been developed for quadrilateral plate osteosynthesis. The objective of this work was to create an implant and a novel approach to simplify and improve acetabular fracture osteosynthesis. Material and methods: A total of 83 patients were studied. Pelvic CT scan images of both acetabula were measured at the proximal and distal posterior column. Implant length, diameters and morphological characteristics were determined. The anatomical features of a novel surgical approach are described. The paramedian approach was performed on a cadaveric specimen to determine its anatomical safety. Results: The screws measured 20 × 6 × 8 mm (length × core diameter x head diameter), with internal threads of 4.5 mm. The Kolmogorov-Smirnov (Lilliefors) test was used, where p had to be > 0.05. Plates were previously determined to be 10 mm wide and 3 mm thick, of variable length. Instruments were developed to surmount difficulties. Discussion: This new procedure and implant could make the repair of acetabular fractures easier and offers several advantages. Clinical trials are needed to assess the benefits of this proposal. The newly described method can allow acetabular fracture osteosynthesis to be performed safely, avoid iatrogenic injury to anatomical structures and achieve better results.

Postoperative Changes in Paraspinal Muscle Volume: Comparison between Paramedian Interfascial and Midline Approaches for Lumbar Fusion

In this study, we compared the paramedian interfascial approach (PIA) and the traditional midline approach (MA) for lumbar fusion to determine which approach resulted in the least amount of postoperative back muscle atrophy. We performed unilateral transforaminal posterior lumbar interbody fusion via MA on the symptomatic side and pedicle screw fixation via PIA on the other side in the same patient. We evaluated the damage to the paraspinal muscle after MA and PIA by measuring the preoperative and postoperative paraspinal muscle volume in 26 patients. The preoperative and postoperative cross-sectional area, thickness, and width of the multifidus muscle were measured by computed tomography. The degree of postoperative paraspinal muscle atrophy was significantly greater on the MA side than on the contralateral PIA side (-20.7% and -4.8%, respectively, p<0.01). In conclusion, the PIA for lumbar fusion yielded successful outcomes for the preservation of paraspinal muscle in these 26 patients. We suggest that the success of PIA is due to less manipulation and retraction of the paraspinal muscle and further studies on this technique may help confirm whether less muscle injury has positive effects on the long-term clinical outcome.

What is the Optimal Angle of Needle Insertion in Korean Young Adult Male during Paramedian Spinal Puncture? A Radiological Study / 대한마취과학회지

BACKGROUND: The object of this study is to offer the optimal angle of needle insertion during L3-L4 paramedian approach using simple X-ray. METHODS: Twenty-five male patients were enrolled for this study. After placing a radio-opaque material (RO) on the point 1cm lateral and 1cm caudad to inferior edge of L3 spinous process in the sitting-flexion position, simple AP X-ray films in erect position and lateral films in sitting-flexion position were taken. The distance from RO (I) to the midline of vertebral column was measured on the AP film. On the lateral film, the optimal target point (T) was determined. When the real RO (I) appeared on lateral film, the point was named I'. The line perpendicular to the line tangential to skin on I' was drawn to the vertebral body. When another line perpendicular to that line was drawn from the target point (T), the two lines meet perpendicularly at the point C. Two triangles can be formed three-dimensionally with T, I', C and T, I, C. Medial insertion angle (alpha, angle I-C-I') and cephalad insertion angle (beta, angle T-I-C) were calculated. RESULTS: The mean angle of alpha was 10.7 +/- 2.3degrees and beta was 13.9 +/- 5.0degrees. The insertion based on the calculated angles was successfully achieved at the first trial in 24 patients and at the second in 1 patient. CONCLUSIONS: Spinal anesthesia with L3-L4 paramedian approach can be successfully performed using calculated angles measured by simple X-rays.

Prediction of the Distance from Skin to Mid-Thoracic Epidural Space by Computed Tomography / 대한마취과학회지

BACKGROUND: Although thoracic epidural analgesia is a common practice in neuroaxial blockade for effective post-operative pain relief especially in major abdominal or thoracic surgery, difficult access to the thoracic epidural space is a frequent problem and can cause neurological complications like spinal cord injury and total spinal block. To minimize complications, we should to guess the distance for thoracic epidural space before this procedure. METHODS: One hundred fifty patients having preoperative upper abdominal computed tomography (CT) for diagnosis of their disease presented to major abdominal operation requiring mid-thoracic epidural analgesia for postoperative pain relief. The patient was placed in the sitting position and the levels of T7 and T8 spinous processes were identified. Using a paramedian approach with loss of resistance technique, when the insertion angles of Tuohy needle was measured by a protractor; inward angle (alpha) to the sagittal plane and downward angle (beta) to the transverse section of the spine. Entry of the needle into the epidural space, actual length (A) of the needle was marked and then measured with a ruler. Reviewing the abdominal CT films using the Picture Archiving and Communication System (PACS), the distance (B) from epidural space to skin on the transverse CT plane was measured at the corresponding to T7-T8 seemed to the level of the lowest scapular. The estimated length (Ac) of the skin to the epidural space was calculated by principle of trigonometry with alpha, beta and B. RESULTS: Mean (SD) age, height, weight, BMI were 56 (11) yr, 164 (6.9) cm, 61 (11.5) kg, and 37 (6.2) kg/m2, respectively. The A, B, Ac value and alpha, beta were 5.4 (0.77), 4.3 (0.76), 5.4 (0.85), 12 (3.4)o, 33 (9.6)o. There were significant correlation of both actual length of the needle and the estimated distance on CT film. Actual length of the needle tended to have 1.25 times longer than the estimated distance on CT film. There were also significances both A and weight, BMI, but not age, height. CONCLUSIONS: The distance from epidural space to skin measured on the transverse CT plane may be helpful as a guide for mid-thoracic epidural catheter insertion.

Clinical Experiences in the Treatment of Far Lateral Lumbar Disc Herni

The authors present 12 cases of far lateral disc herniation(FLDH) diagnosed and treated in our institution from march, 1992 to February, 1994. In the author's series the incidence of far lateral disc herniation was 5% of all lumbar disc herniations. The average age of the patients was 4 years and there were 7 men and 5 women. The L4-5 intervertebral disc level was the most commonly involved level. All patients initially presented with symptoms of radiculopathy. Cases with double herniations at the same level and on the same side seemed to have the most potential source of misdiagnosis and mismanagement, and a careful surgical consideration was needed for such cases. In 4 cases, a combined intraspinal and extraforaminal approach was performed with preservation of facet joints and in 2 cases, paramedian muscle splitting approach was performed. Chemonucleolysis and the usual partial hemilaminectomy were undertaken in 5 cases and in 1 case, respectively. The combined approaches proved to be an effective means of treatment for cases with double herniations, but misdiagnosis of such lesion can lead to an inappropriate and an ineffective treatment and poor surgical results. Furthermore, in the diagnosis of far lateral disc herniation, differentiation must be made from symptoms of conjoined nerve root and congested epidural vein.

Far Lateral Lumbar disc Herniation

Far lateral disc herniation(FLDH) with compression of the nerve root as it exits through the foramen has been a recognized entity for a number of years. Failure to diagonose and precisely localize these herniations can lead to unsuccessful surgical exploration or exploration of the innocent interspace. If these herniation are diagnosed, they often cannot be adequately exposed by the classic minline hemilaminectomy approach. A partial or complete unilateral facetectomy to expose these herniations can lead to vertebral instability or contribute to continued postoperative back pain. The authors present 5 patients who were diagnosed as having far lateral lumbar disc herniations from 1988 to 1990. Two of these were at L4-5 level, two at L5-S1 level and one at L3-4 level and all were over 60 years old. High resolution CT scan appeared to be the best study and the paramedian muscle splitting microsurgical approach, done in 3 cases, was found to be the most direct and favorable anatomical route to FLDH for vertebral stability and minimal postoperative back pain.