Lumbar Single-Level Dynamic Stabilization with Semi-Rigid and Full Dynamic Systems: A Retrospective Clinical and Radiological Analysis of 71 Patients

BACKGROUND: This study compares the clinical and radiological results of three most commonly used dynamic stabilization systems in the field of orthopedic surgery. METHODS: A total of 71 patients underwent single-level posterior transpedicular dynamic stabilization between 2011 and 2014 due to lumbar degenerative disc disease. Three different dynamic systems used include: (1) the Dynesys system; (2) a dynamic screw with a PEEK rod; and (3) a full dynamic system (a dynamic screw with a dynamic rod; BalanC). The mean patient age was 45.8 years. The mean follow-up was 29.7 months. Clinical and radiological data were obtained for each patient preoperatively and at 6, 12, and 24 months of follow-up. RESULTS: Clinical outcomes were significantly improved in all patients. There were no significant differences in the radiological outcomes among the groups divided according to the system used. Screw loosening was detected in 2 patients, and 1 patient developed screw breakage. All patients with screw loosening or breakage underwent revision surgery. CONCLUSIONS: Each procedure offered satisfactory outcome regardless of which system was applied.

Disc Rehydration after Dynamic Stabilization: A Report of 59 Cases

STUDY DESIGN: A retrospective study investigating decrease in the nucleus pulposus signal intensity or disc height on magnetic resonance imaging (MRI) and disc degeneration. PURPOSE: Although a degenerated disc cannot self-regenerate, distraction or stabilization may provide suitable conditions for rehydration and possible regeneration. This study aimed to evaluate clinical outcomes and disc regeneration via MRI in a series of patients with degenerative disc disease (DDD) who underwent lumbar stabilization with a dynamic stabilization system (DSS). OVERVIEW OF LITERATURE: A dynamic system provides rehydration during early DDD. METHODS: Fifty-nine patients (mean age, 46.5 years) who undedwent stabilization with DSS for segmental instability (painful black disc) between 2004 and 2014 were retrospectively evaluated. All patients underwent MRI preoperatively and 12 months postoperatively. Intervertebral disc (IVD) degeneration grades at the implanted segment were categorized using the Pfirrmann classification system. Patients were followed for a mean of 6.4 years, and clinical outcomes were based on visual analog scale (VAS) and Oswestry disability index (ODI) scores. RESULTS: Significant improvements in back pain VAS and ODI scores from before surgery (7 and 68%, respectively) were reported at 6 (2.85 and 27.4%, respectively) and 12 months postoperatively (1.8 and 16.3%, respectively). Postoperative IVD changes were observed in 28 patients. Improvement was observed in 20 patients (34%), whereas progressive degeneration was observed in eight patients (13.5%). Thirty-one patients (52.5%) exhibited neither improvement nor progression. Single Pfirrmann grade improvements were observed in 29% of the patients and two-grade improvements were observed in 5%. CONCLUSIONS: Our observations support the theory that physiological movement and a balanced load distribution are necessary for disc regeneration. We conclude that DSS may decelerate the degeneration process and appears to facilitate regeneration.

Novel Foraminal Expansion Technique

The technique we describe was developed for cervical foraminal stenosis for cases in which a keyhole foraminotomy would not be effective. Many cervical stenosis cases are so severe that keyhole foraminotomy is not successful. However, the technique outlined in this study provides adequate enlargement of an entire cervical foraminal diameter. This study reports on a novel foraminal expansion technique. Linear drilling was performed in the middle of the facet joint. A small bone graft was placed between the divided lateral masses after distraction. A lateral mass stabilization was performed with screws and rods following the expansion procedure. A cervical foramen was linearly drilled medially to laterally, then expanded with small bone grafts, and a lateral mass instrumentation was added with surgery. The patient was well after the surgery. The novel foraminal expansion is an effective surgical method for severe foraminal stenosis.

Enlargement of Neural Foramina and Dynamic Stabilization in Spondylolisthesis without Restoring the Alignment: Technical Note

It is well known that the cause of radiculopathy is the compression of the nerve root within the foramina which is narrowed secondary to sliding of the corpus and reduced disc height. In some patients, unroofing the foramen does not resolve this problem. We described a new decompression technique using pedicle removal and transpedicular dynamic instrumentation to stabilization the spine. We performed this operation in 2 patients and achieved very good results.