Mobidisc® Lumbar Multicenter - 2 Yr 80 pts: 2008 Jun Euro.Fed.Nat.Assoc.Ortho.Traum.

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9th Congress of the European Federation of National Associations of Orthopaedics and Traumatology
Nice, France
29 May - 1 June 2008
Link

Poster: Nice PDF w/Tables & Graphs

Abstract: PDF, text only

P805

Mobidisc® Lumbar Arthroplasty:

Multicenter Study with 2-Years Follow-Up

Jerome Allain, Jacques Beaurain, Joel Delécrin, Jean Steib, Hervé Chataigner, Thierry Dufour, Lucie Abourg


Purpose:
Biomechanically, the Mobidisc® Lumbar Arthroplasty System was designed with a mobile nucleus to allow both rotation and translation during intersegmental vertebral motion in physiologic conditions. The following clinical results are from an ongoing prospective and multi-center study evaluating the first 80 patients with 2 years follow-up. Due to the biomechanical specificity of the Mobidisc prosthesis, the study also reports range of motion (ROM), center of rotation (CR) and mobility of the nucleus against the prosthesis endplates.

Methods:
Eighty consecutive patients who received 87 Mobidisc prostheses, implanted transperitoneal or retroperitoneal, have been followed-up prospectively for 2 years. In addition to the standard clinical assessments (VAS 0-10 scale for back and leg pain, Oswestry, and SF-36 scores), employment patterns and urinary and sexual functions were evaluated preoperatively and at 3, 6, 12, and 24 months after surgery. Calculation of the ROM and CR were performed with SpineView® Software. Mobility of the nucleus was assessed thanks to a marker inserted within the polyethylene.

Results:
The mean age of the 80 patients was 41±7.1 years; 68% were female. 91% of the patients received an implant at one-level and 9% were operated at two levels.

After two years, Oswestry and lumbar and leg VAS scores decreased significantly compared to pre-operative values from 50% to 23%, from 6.8 to 2.6, and from 6.7 to 3.4 respectively.

The SF-36 quality of life score was also significantly improved for both Physical and Mental Component Scales (mean improvement of 13.6 and 10.4pts compared with pre-op for PCS and MCS respectively).

After 2 years, 75% of the patients were satisfied regarding low back pain and 67% regarding leg pain. 84.8% of the patients experienced an improvement for VAS back pain of at least 2 points compared with pre-op value and 74.4% of the patients had an improvement of the Oswestry score of at least 15 points.

Clinical results at 1 and 2 years were equivalent. Preoperatively, 68.1% of patients were on sick-leave (from 2 to 72 months) and 26.4% were working. Among the patients who were preoperatively on sick-leave, 63.3% had returned to work after 1 year post surgery and 81.6% after 2 years, cumulating in full-time and part-time jobs. No mechanical failure of the implants or loosening was observed. After 2 years, 2 retrograde ejaculations, 1 vaginal dryness, and 6 pollakiuria persisted.

Concerning mobility, 83.1% of L5-S1 prostheses had a ROM superior or equal to 2° and 59.6% had a ROM superior or equal to 5°. For L4-L5 prostheses, 87% had a ROM superior or equal to 2° and 66.7% had a ROM superior or equal to ?5°. In the group with a ROM superior to 5°, 87% of the CR appeared physiologic.

ROM was significantly increased after 2 years compared to the pre-op values, with a ROM averaging 6.5° and 7.4° at L5-S1 and L4-L5 levels respectively.


Conclusion:
This study demonstrates a convincing profile for safety and efficacy of the Mobidisc device, with clinical improvements maintained after 2 years of followup. This younger patient population at 2 years follow-up had a high rate of employment that fulfills a key treatment goal of economic reintegration.

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Use of Analgesics
____ Pre-Op - Mn3 - Mn6 -- Yr1 -- Yr2
Never-- 10% _ 52% _ 54% _ 60% _ 63%
Somtim 24% _ 21% _ 24% _ 17% _ 13%
Contins 65% _ 27% _ 22% _ 23% _ 25%

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80 patients is a subset of an on-going trial. Average age of patients appears young.

Clinicaltrials.gov has an ongoing trial with MobiDisc in France. One of the document links above, the nice poster, is from the SIAD group, Italy, scratching my head, author names appear to be French and it's too late for a pubmed look-up / search for details. Siad Link


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