**Arthroplasty of Spine and Upper Extremity**

496 Recent Advances in Arthroplasty

[26] Vichinsky EP, Neumayr LD, Earles AN, Williams R, Lennette ET, Dean D, Nickerson B,

Study Group. N Engl J Med, 2000;342:1855–1865.

Orringer E, McKie V, Bellevue R, Daeschner C, Manci EA. Causes and outcomes of the acute chest syndrome in sickle cell disease. National Acute Chest Syndrome

**23** 

*USA* 

Bruce V. Darden

**Cervical Disc Arthroplasty** 

For more than 50 years, anterior cervical discectomy and fusion (ACDF) has been the workhorse procedure for cervical degenerative pathology. (Bailey & Badgely, 1960; Cloward, 1961; Robinson & Smith, 1955) The procedure has yielded successful results clinically in multiple large series. (Bohlman et al, 1993; Gore & Sepic, 1984) Advances in allograft and cage techniques as well as the use of anterior plating systems have diminished complications in ACDF. However, concerns about adjacent segment degeneration (ASD) have tempered some enthusiasm for the procedure. Gore et al (Gore & Sepic, 1998) reviewed a series of 50 ACDF patients followed long term. Almost universally, the patients developed ASD. One-third of the cohort developed recurrent pain with half of the symptomatic group requiring additional surgery. Hilibrand et al (Hilibrand et al, 1999) evaluated a group of 374 patients undergoing ACDF. They showed a 2.9% per year risk of development of symptomatic ASD, with two thirds of the symptomatic patients requiring additional surgery. Goffin et al (Goffin et al, 1995) prospectively followed a series of ACDF patients who underwent the procedure for either a degenerative or traumatic condition. Follow-up was for five to nine years. Sixty percent of the patients developed ASD, equally distributed between the older degenerative population and the younger traumatic population, providing evidence that fusion may accelerate degenerative changes. Goffin et al (Goffin et al, 2004) reviewed a larger series of ACDF patients followed for an average of 8.3 years. In this group, 92% of the patients developed ASD, though they had a much lower rate of additional surgical procedures, 6.1% for the entire length of follow-up, distinctly lower than Hilibrand et al. Numerous cadaveric biomechanical studies (Eck et al, 2002; Pospiech et al, 1999) evaluating adjacent level intradiscal pressures and range of motion in simulated fusion models have shown that both increase after fusion. These altered biomechanics may

Against this background, centers began experimenting with cervical disc arthroplasty in the 1980s. Cummins and collaborators at the Frenchay Hospital, Bristol, England developed a metal-on-metal ball and socket arthroplasty and implanted it on a small series of patients in the 1990s. (Cummins et al, 1998) The arthroplasty underwent a number of design changes and is now known as Prestige. Bryan, in the US, developed a one piece metal-on-polymer device called the Bryan Cervical Disc Replacement, initially evaluated clinically in Europe. (Goffin et al, 2002) ProDisc-C arthroplasty is a metal-on-polyethylene implant adopted from the ProDisc-L lumbar disc arthroplasty developed by Thierry Marnay. (Delamarter & Pradhan, 2004) Since

**1. Introduction** 

thus accelerate ASD.

 *OrthoCarolina Spine Center, Charlotte* 
