Anterior Longitudinal Ligament Reconstruction to Reduce Hypermobility of Cervical and Lumbar Disc Arthroplasty

STUDY DESIGN: Retrospective case series PURPOSE: This study aims to present the early clinical and radiological outcomes of anterior longitudinal ligament (ALL) reconstruction following disc arthroplasty. OVERVIEW OF LITERATURE: Although cervical and lumbar disc arthroplasty have entered the clinical setting, there are still concerns regarding the short and long term complications arising from hypermobility of current prosthesis designs. Reconstruction of the ALL is a potential solution to disc arthroplasty hypermobility. METHODS: ALL reconstruction following disc arthroplasty have been performed by the senior author over a 24 month period. Ligament replacements used include allograft and synthetic, ligament advanced reinforcement system (LARS) ligaments. Methods of fixation used include titanium staples, bone anchors and suture fixation. Radiological follow-up pre- and postoperative Oswestry disability index, Neck Disability Index, Patient Satisfaction index scores were recorded on all patients. RESULTS: A total of 18 ALL reconstructions were performed. There have been no cases of early complications, revision surgery for recurrent symptoms or implant failure. Of the 6 patients receiving a minimum of 15 months follow-up, 4 patients received an allograft, 2 patients received the LARS ligament. Favourable, postoperative clinical and radiographic outcomes have been demonstrated. CONCLUSIONS: ALL reconstruction following cervical and lumbar disc arthroplasty is a promising solution to addressing non-physiological kinematics of current disc arthroplasty devices. Randomized, controlled studies with larger study samples and long-term follow-up are required to establish these conclusions.

Long-Term Objective Physical Activity Measurements using a Wireless Accelerometer Following Minimally Invasive Transforaminal Interbody Fusion Surgery

We report on a case of a patient who underwent minimally invasive transforaminal lumbar interbody fusion (mi-TLIF) with objective physical activity measurements performed preoperatively and postoperatively at up to 12-months using wireless accelerometer technology. In the first postoperative month following surgery, the patient had reduced mobility, taking 2,397 steps over a distance of 1.8 km per day. However, the number of steps taken and distance travelled per day had returned to baseline levels by the second postoperative month. At one-year follow-up, the patient averaged 5,095 steps per day in the month over a distance of 3.8 km; this was a 60% improvement in both steps taken and distance travelled compared to the preoperative status. The use of wireless accelerometers is feasible in obtaining objective physical activity measurements before and after lumbar interbody fusion and may be applicable to other related spinal surgeries as well.