Treatment strategies for generator pocket pain.

OBJECTIVE Generator site pain is a relatively common phenomenon in patients undergoing spinal cord stimulation (SCS) that complicates management and effective pain relief. This pain may be managed conservatively, with repositioning of the battery and in some cases with explant. Here we explore our experience with management of generator site pain ('pocket pain') in a large single-center study. METHODS All SCS permanent implants and implantable pulse generator (IPG) placements over 9 years were reviewed. Of 785 cases, we identified 43 patients with pocket pain (5.5%). Demographics and treatments of the pocket pain cohort were analyzed. RESULTS The mean age (± SEM) of the pocket pain cohort was 46.86 ± 1.06 and there were 10/33 males/females. Females were overrepresented in pocket pain cohort (76.7%) when compared to the total SCS cohort (59.0%) (X2 = 5.93, p = 0.015). Diagnosis included failed back surgery syndrome (51.2%), complex regional pain syndrome (23.3%), and chronic neuropathic pain (25.5%). No patients improved with conservative therapy. All patients either went on to revision (n = 23) or explant (n = 20). Time from initial surgery to development of pocket pain was 7.5 months (range: 0.3-88) and from pocket pain to revision surgery was 4.5 months (range: 0.4-26). In addition, significantly more pocket pain patients (65.1%) had workers' compensation (WC) insurance compared to patients without pocket pain (24.9%) (X2 = 33.3, p < 0.001). CONCLUSION In our institutional experience, pocket pain was inadequately managed with conservative treatments. Being female and having SCS filed under WC increased risk of pocket pain. Future work will explore the nuances in device placement based on body shape and manual activity responsibilities.