RESUMO
INTRODUCTION: Patients diagnosed with a lumbar disc hernia and nerve root compression, in which conservative treatment failed are candidates for lumbar discectomy. This technique often results in failed spine surgery syndrome which includes different complications such as arachnoiditis, discitis, and sac tears resulting in pain and neurological deficit. This has led to research of minimally invasive surgery in which the medullary canal is not involved and is performed under local anesthesia. In order to perform this technique, the anatomical and radiological identification of the intervertebral foramina is necessary. Kambin's triangle is an anatomical safe place for percutaneous procedures. OBJECTIVES: (1) To identify Kambin's triangle in the cadaver and its anatomical elements. (2) To describe the relationship between cutaneous lines traced on the patient with the anatomic elements in the cadaver by using guide needles. (3) To describe the position of the surgical instruments used in a posterolateral discectomy approach to identify the triangle. METHODS: (1) Dissection through a standard approach to L1-L5 foramina. (2) Observation of the anatomic planes that the guide needle follows. (3) Radiological study of the foramen. (4) Positioning of the surgical instruments on the foramen to establish the size and space. RESULTS: (1) The intervertebral foramina were dissected and the anatomical components of Kambin's triangle were identified, also we compared size of this triangle (10 mm) and compared it with surgical instruments (7 mm). (2) Skin lines were tested as reliable and safe routes to identify foramina. (3) We proved safety of endoscopic surgery instruments by a posterolateral approach. (4) A visual aid was developed for adequate placement of the guide needle through the foramen. CONCLUSIONS: (1) Foramina need to be perfectly identified with image techniques so that the surgical instruments can be placed safely. (2) Skin lines are a safe and reliable guide. (3) The technique is safe if performed through Kambin's triangle.
Assuntos
Vértebras Lombares/anatomia & histologia , Pinos Ortopédicos , Cadáver , Discotomia/métodos , Humanos , Deslocamento do Disco Intervertebral/cirurgiaRESUMO
UNLABELLED: Even though lumbar discography was described in 1948 by Lind Bloom as a useful diagnostic method to identify ruptures of the anulus fibrosus of the intervertebral disc, it was neglected for many years as an unreliable method. This happened especially after a publication by Holt, who in 1968 reported a 37% false-positive rate in a study done among inmates, with a very irritating contrast medium (hypaque) that was administered intrathecally. OBJECTIVE: To show that lumbar discography is a dynamic and safe method and even more reliable than magnetic resonance imaging to detect intervertebral disc ruptures. MATERIAL AND METHODS: Thirty-three patients with a clinical history of lumbosciatic pain lasting more than 6 months and an MRI-proven diagnosis of herniated disc were studied. Fifty discographies were performed at the L3-4, L4-5, L5-S1 spaces. They were considered as negative: (1) When the contrast had an oval or cotton-ball shape. (2) When the disc admitted 2-2.5 cm of contrast medium without causing any pain. They were considered as positive: When the contrast dye diffused with an irregular pattern. (2) When the administration of the contrast dye was painful. All negative discographies were followed-up for 6 months. RESULTS: Thirty-three patients; 22 males, 11 females; 50 discographies as follows: 5 at L3-4; 27 at L4-5; and 18 at L5-S1. Five discographies were negative, At six months, the patients were asymptomatic. The discography detected 5 patients, equivalent to a 10% false/positive rate for the magnetic resonance imaging. Two patients developed diskitis. CONCLUSIONS: Discography is more effective than magnetic resonance imaging for detecting intervertebral disc ruptures. Patients with diskitis were related with minimally invasive surgery, probably more due to the infectious process than to discography.