ADJACENT LEVEL DEGENERATION AND POST-TRAUMATIC DEFORMITY AFTER THORACOLUMBAR FRACTURES

ABSTRACT Objectives: To evaluate thoracolumbar fractures and the complications such as adjacent disc degeneration (ADD) and post-traumatic deformity. Methods: We evaluated 32 patients divided into two equal groups, 16 in the case group (removal of the synthesis material) and 16 in the control group (not submitted to removal of the synthesis material) in order to verify if there was difference between the incidence of these complications. Results: There were no statistically significant differences between the groups regarding the progression of the ADD and the post-traumatic deformity, but both progressed during the 2-year follow-up. Conclusion: It was concluded that the removal of the synthesis material was not effective in preventing these complications after surgical fractures of the thoracolumbar spine.

Treatment of Degenerative Disc Disease with the ProDisc-C Cervical Disc Prosthesis: Literature Review, Interdisciplinary Aspects and Personal Experience

Cervical disc herniations represent the most frequent cervical-level pathology in patients aged 40 and above. Symptoms usually include C6-C7 radiculopathy, which has a prevalence of 3.3/1000 individuals. There still is a debate on whether any gender is more frequently affected, as some authors report women are more frequently affected [2, 3] while others claim both genders are equally affected. Ever since the 1950s the standard treatment for such patients was represented by Anterior Cervical Discectomy and Fusion (ACDF), however, concern for the development of adjacent level degeneration after the fusion of mobile vertebral segments has increased the interest in developing new dynamic disc prostheses designed to mimic the functions and natural motion of the spine. The purpose of this paper is to summarize, in a comprehensive literature-review-type article, the existing data regarding the ProDisc-C spinal implant within the OVID, SCOPUS and MEDLINE databases while at the same time presenting the personal experience of the authors using the above-mentioned implant.

Five-year adjacent-level degenerative changes in patients with single-level disease treated using lumbar total disc replacement with ProDisc-L versus circumferential fusion

Object The authors report the 5-year results for radiographically demonstrated adjacent-level degenerative changes from a prospective multicenter study in which patients were randomized to either total disc replacement (TDR) or circumferential fusion for single-level lumbar degenerative disc disease (DDD). Methods Two hundred thirty-six patients with single-level lumbar DDD were enrolled and randomly assigned to 2 treatment groups: 161 patients in the TDR group were treated using the ProDisc-L (Synthes Spine, Inc.), and 75 patients were treated with circumferential fusion. Radiographic follow-up data 5 years after treatment were available for 123 TDR patients and 43 fusion patients. To characterize adjacent-level degeneration (ALD), radiologists at an independent facility read the radiographic films. Adjacent-level degeneration was characterized by a composite score including disc height loss, endplate sclerosis, osteophytes, and spondylolisthesis. At 5 years, changes in ALD (ΔALDs) compared with the preoperative assessment were reported. Results Changes in ALD at 5 years were observed in 9.2% of TDR patients and 28.6% of fusion patients (p = 0.004). Among the patients without adjacent-level disease preoperatively, new findings of ALD at 5 years posttreatment were apparent in only 6.7% of TDR patients and 23.8% of fusion patients (p = 0.008). Adjacent-level surgery leading to secondary surgery was reported for 1.9% of TDR patients and 4.0% of fusion patients (p = 0.6819). The TDR patients had a mean preoperative index-level range of motion ([ROM] of 7.3°) that decreased slightly (to 6.0°) at 5 years after treatment (p = 0.0198). Neither treatment group had significant changes in either ROM or translation at the superior adjacent level at 5 years posttreatment compared with baseline. Conclusions At 5 years after the index surgery, ProDisc-L maintained ROM and was associated with a significantly lower rate of ΔALDs than in the patients treated with circumferential fusion. In fact, the fusion patients were greater than 3 times more likely to experience ΔALDs than were the TDR patients. Clinical trial registration no.: NCT00295009.

Biomechanics of Disc Degeneration

Disc degeneration and associated disorders are among the most debated topics in the orthopedic literature over the past few decades. These may be attributed to interrelated mechanical, biochemical, and environmental factors. The treatment options vary from conservative approaches to surgery, depending on the severity of degeneration and response to conservative therapies. Spinal fusion is considered to be the “gold standard” in surgical methods till date. However, the association of adjacent level degeneration has led to the evolution of motion preservation technologies like spinal arthroplasty and posterior dynamic stabilization systems. These new technologies are aimed to address pain and preserve motion while maintaining a proper load sharing among various spinal elements. This paper provides an elaborative biomechanical review of the technologies aimed to address the disc degeneration and reiterates the point that biomechanical efficacy followed by long-term clinical success will allow these nonfusion technologies as alternatives to fusion, at least in certain patient population.