Is sequestrectomy a viable alternative to microdiscectomy? A systematic review of the literature.

BACKGROUND: Traditionally, lumbar discectomy involves removal of the free disc fragment followed by aggressive or conservative excision of the intervertebral disc. In selected patients, however, it is possible to remove only the free fragment or sequester without clearing the intervertebral disc space. However, there is some controversy about whether that approach is sufficient to prevent recurrent symptoms and to provide adequate pain relief. QUESTIONS/PURPOSES: This systematic review was designed to pose two questions: (1) Does performing a sequestrectomy only without conventional microdiscectomy lead to an increased reherniation rate; and (2) is there a difference in the patient-reported levels of radicular pain? METHODS: Systematic MEDLINE and EMBASE searches were carried out to identify all articles published in peer-reviewed journals reporting the outcomes of interest for conventional microdiscectomy versus sequestrectomy for lumbar disc herniation from L2 to the sacrum (Level III evidence and above); hand-searching of bibliographies was also performed. A minimum of Level II evidence was required with a followup rate of greater than 75%. Followup in all studies was from 18 to 86 months. Seven studies met the inclusion criteria for this review. The studies were analyzed for operating time, hospital stay, pre- and postoperative visual analog scale, and reherniation rate. RESULTS: Patients in both the microdiscectomy and sequestrectomy groups showed comparable improvement of visual analog scale (VAS) score for leg pain. VAS score improvement ranged from 5.6 to 6.5 points in the microdiscectomy groups and 5.5 to 6.6 in the sequestrectomy group. The reherniation rate in the microdiscectomy group ranged from 2.3% to 11.8% and in the sequestrectomy groups from 2% to 12.5%. CONCLUSIONS: This review of the available literature suggests that, compared with conventional microdiscectomy, microsurgical lumbar sequestrectomy can achieve comparable reherniation rates and reduction in radicular pain when a small breach in the posterior fibrous ring is found intraoperatively.

Precision of periprosthetic bone mineral density measurements using Hologic Windows versus DOS-based analysis software.

Dual energy X-ray absorptiometry (DXA) is a precise tool for measuring bone mineral density (BMD) around total joint prostheses. The Hologic "metal-removal hip" analysis package (Hologic Inc., Waltham, MA) is a Microsoft DOS-based analysis platform that has undergone a change in the operating platform to a Microsoft Windows-based system that has also incorporated changes to DXA image manipulation on-screen. We evaluated the impact of these changes on instrument precision by analysis of sequential DXA scans taken on the same day using the Hologic QDR-4500A fan beam densitometer (Hologic Inc.) in 29 subjects after total hip arthroplasty. The coefficient of variation percentage (CV%) for the net pelvic region was 3.04 for Windows versus 2.36 for DOS (p>0.05). The CV% for the net femoral region was 1.75 for Windows versus 1.51 for DOS (p>0.05). Absolute BMD values for the net pelvic and net femoral regions were similar (Bland-Altman, Windows minus DOS; pelvic region mean=-1.0%; femoral region mean=1.3%; p>0.05 for both comparisons). Our results suggest that scans analyzed using each platform may be used interchangeably without the need for a calibration correction.