Abstract
Introduction
The implantation of DIAM in interspinous space is believed to act as facet joints and provides stability to operated segment by shifting instantaneous axis of rotation forward in lordotic disorders. In this retrospective study, the patients who underwent lumbar surgery with DIAM (Medtronic Sofamor, Danek) spacer implants were followed up with an aim to evaluate the clinical outcomes. To our knowledge, this is the largest series with longest follow up.
Material Methods
Patients who underwent lumbar surgery (discectomy and decompression) with concomitant placement of DIAM spacer within a 36-months period were included. A total of 52 patients including equal number of male (n=26) and female (n=26), were followed up for 12 to 45 months (Mean: 22 months).
Results
Total of 77 DIAM implanted; L1/2 (n=1), L3/4 (n=9), L4/5 (n=31), L5/S1 (n=26). 27 patients received DIAM at one level and 25 at 2-levels. Patients experienced significant pain reduction and functional improvement at final follow up. In single level surgery, mean ODI improved from 50.03 pre-operatively to 31.23 post-operatively. The mean pre op VAS-BP & VAS-LP scores were 7.66 & 7.03, which were reduced to 4.29 & 3.55 respectively. In two level surgery mean pre op ODI, VAS-BP VAS-LP were 45.71, 6.71 & 6.42 pre-operatively which improved to 32.20, 3.97 and 3.82 at follow up respectively.
Conclusion
Significant improvement of pain and function have been noted following the use of DIAM. Furthermore, DIAM interspinous implantation is less invasive and preserves much of the deep posterior structures compared to semi rigid instrumented dynamic stabilisation devices. Our long-term results of the cohort demonstrate that DIAM spacer implantation is effective in relieving pain and improving functional outcome.
