A Prospective, Multicenter Observational Study on MAST™ (Minimal Access Spinal Technologies) Fusion Procedures for the Treatment of the Degenerative Lumbar Spine

The aim of the study is to observe and document surgical practice and evaluate patients' outcomes following a MAST™ single or double level instrumented fusion procedure using PLIF (Posterior Lumbar Interbody Fusion) or TLIF (Transforaminal Lumbar Interbody Fusion) techniques for the treatment of the degenerative lumbar spine in a "real-world" patient population.

Instrumented lumbar fusion is usually done through an open procedure which involves an excessive intraoperative dissection and retraction of the paraspinal musculature leading, in a short term basis, to a prolonged recovery time from the surgery. This open approach is frequently associated with significant blood loss and need of transfusion, produces the majority of the perioperative pain, increases hospital stay and the chances of infection and delays the return to normal activities and to work. In a long term basis, the open procedure leads to denervation, atrophy and loss of the muscles independent function, resulting in an increased risk of "fusion disease", a term that has been coined to describe its occurrence.

The minimally invasive spinal surgery was developed as a potential solution to the above-mentioned problems by reducing the amount of iatrogenic soft tissue injury while reaching the same traditional goals of the open procedures. Besides minimizing the long-term effects of exposure-related muscle injury, minimally invasive lumbar fusion techniques hold the promise of immediate short-term advantages. Patients undergoing minimally invasive procedures are reported to recover earlier from the surgery. Shorter time to first ambulation, less pain medication consumption, less blood loss, less required transfusion, shorter hospital stay and earlier return to work are generally associated with the minimally invasive procedure as compared to the standard open surgeries. The minimally invasive access requires a surgical corridor targeted on the disease which is accomplished by using a series of tubular muscle dilators allowing a clear intraoperative visualization to perform these procedures together with the parallel use of image guided percutaneous insertion of pedicle screws and instrumentation.

The purpose of this study is to observe and document surgical practice and evaluate patients' outcomes following a MAST™ single or double level instrumented fusion procedure using PLIF or TLIF techniques for the treatment of the degenerative lumbar spine in a "real-world" patient population.

Eligibility Criteria:
Inclusion Criteria:

* Patient is \>18 years of age (or minimum age as required by local regulations).
* Patient has indication for a single or double level instrumented lumbar fusion for the treatment of the degenerative lumbar spine.
* Patient agrees to participate in the study and is able to sign the Data Release Form/Informed Consent.
* The procedure planned for the patient complies with the labeling of the Devices that may be used in the surgical procedure as described in the section B.2 Device Information.
* Patient is planned to be submitted to the fusion procedure using PLIF or TLIF techniques and to receive a CD HORIZON® Spinal System via a MAST™ approach.
* The patient is willing and is able to cooperate with study procedures and required follow-up visits.

Exclusion Criteria:

* Patient that has already undergone an open lumbar spine surgery other than microdiscectomy.
* Indications for the procedure other than degenerative spine disease like Osteoporotic vertebral fractures, Spine trauma fractures and Spine tumor.

In order to reduce as much as possible bias in this observational study, the study centers should propose the study to all consecutive individuals who meet these in and exclusion criteria to participate in the study in order to comply with the 'real world' population concept. This observational study does not require any specific test or procedure that falls outside a standard surgical procedure and patient follow-up as routinely done in the hospital. Some data was collected only for centers that applied such procedures as standard of care.