Translaminar microsurgical approach for lumbar herniated nucleus pulposus (HNP) in the "hidden zone" - Clinical and radiologic results in a series of 24 patients

Study Design. Clinical series. Objective. To describe an alternative surgical approach for disc herniations in the "hidden zone." Summary of Background Data. Many spine surgeons have suggested different surgical approaches for symptomatic preforaminal and foraminal disc herniations. However, almost every surgical approach has certain shortcomings when it comes to exposing the "hidden zone" without causing some degree of spinal instability. Methods. Twenty-four patients with preforaminal and foraminal disc herniation underwent surgical treatment via a translaminar microsurgical approach. Results. Excellent results were obtained in all patients in terms of pain relief, and all had improvement in motor strength except for 1 patient. No spinal instability was seen at the latest follow-up. Conclusions. A classic interlaminar interspace approach combined with a very limited translaminar fenestration seem to be an acceptable surgical method for accessing a preforaminal disc herniation, and this technique has proven to be safe and did not cause any instability at the latest follow-up.