A new study published in Spine examines total disc replacement for patients with collapsed cervical discs.
The study examined data collected from a single-arm, multicenter study that included 30 patients who underwent operations at 48 implanted levels. All the patients received the Spinal Kinetics M6C disc prosthesis, a compressible cervical disc. The disc was 6 mm in height.
The study authors analyzed further a subset of patients who reported a preoperative disc height less than 3 mm. The researchers found:
1. The shorter discs were less mobile than the taller discs before surgery, and when the tall discs were less mobile preoperatively there was a smaller postoperative range of motion than the short discs.
2. There wasn't a significant difference in range of motion between the short and tall discs.
3. After surgery, the collapsed discs were more mobile when compared with all discs combined. Surgeons distracted the implanted discs more than two times over the preoperative height and reported greater range of motion in all combined discs.
4. The discs that were less than 3 mm before surgery "may be amenable to disc arthroplasty" with the compressible disc prosthesis, according to the report.
5. The study authors concluded, "We observed a significant interaction between preoperative index-level disc height and ROM in influencing postoperative ROM."