gms | German Medical Science

Objective: Chronic pain of the knee is common. In Germany, more than 220 000 knee operations were performed annually during the last three years. The rate of chronic pain is reported between 10% and 34% after these operations [1].

Dorsal root ganglion stimulation (DRGS) can treat knee pain selectively with high energy levels. But there are only a few long term results available so far. We studied the long-term outcome of DRGS used in the treatment of chronic neuropathic knee pain. This is a prospective, longitudinal single center investigation.

Methods: Patients (age >18 years) with chronic neuropathic pain in the knees were prospectively examined. After a successful test-trial (duration of 3–14 days, pain decrease >50%), a permanent generator was implanted. The patients were re-examined after 1 year, 2 years, 3 years, 4 years and 5 years. We used the Visual Analogue Scale (VAS), the Pain Disability Index (PDI), the Pain Catastrophizing Scale (PCS), the Brief Pain Inventory (BPI), and, the Beck Depression Inventory (BDI) for our assessments.

Results: We included 42 consecutive patients (18 female, 24 male, mean age 68.8 years, with an age range from 42–82 years, 42/37 to permanent conversion) during the time period from March 2013 until March 2018. Thirty seven patients had a successful test-trial and a generator was implanted subsequently. Results after 5 years: the VAS dropped from Mdn=8 to Mdn=4 (p=0.0001). The PDI decreased from Mdn=47 to Mdn=21 (p=0.003). The PCS decreased from Mdn=37 to Mdn=24 (p=0.001). The BPI dropped from Mdn=77 to Mdn=34 (p=0.003). The BDI decreased from Mdn=38 to Mdn=24 (p=0.010). Ten patients showed complications (23.8%).

Conclusion: DRGS may be an effective long-term method of treating discrete, localized areas of chronic neuropathic pain. We would recommend DRGS for the treatment of chronic neuropathic pain in the knee.