Perineural dexamethasone attenuates liposomal bupivacaine-induced delayed neural inflammation in mice in vivo.

BACKGROUND: Liposomal bupivacaine (Exparel®) is a sustained-release formulation of bupivacaine for use in surgical infiltration anaesthesia. We analysed the histological nerve toxicity and clinical effectiveness of perineural Exparel® alone or with added dexamethasone in a mouse model. METHODS: We assigned 98 mice receiving a perineural sciatic nerve injection into seven groups: sham (n=14, perineural saline), B (n=14, perineural bupivacaine), BDIP (n=14, perineural bupivacaine + intraperitoneal dexamethasone), BDPN (n=14, perineural bupivacaine + perineural dexamethasone), E (n=14, perineural Exparel®), EDIP (n=14, perineural Exparel® + intraperitoneal dexamethasone), and EDPN (n=14, perineural Exparel® + perineural dexamethasone). The duration of thermoalgesic and motor block was evaluated in 49 mice (seven mice randomly selected by group) every 30 min until recovery. Mice were killed for sciatic nerve histological assessment at 14 or 28 days. RESULTS: The median duration of motor block was 90, 120, 120, 120, 180, and 180 min and the duration of thermoalgesic block was 240, 300, 360, 360, 360, and 420 min for groups B, BDIP, BDPN, E, EDIP, and EDPN, respectively. The B group mice showed mild neural inflammation at 14 days and the E group mice showed mild neural inflammation at 28 days. Addition (intraperitoneal or perineural) of dexamethasone reduced neural inflammation induced by bupivacaine, whereas only perineural dexamethasone reduced neural inflammation induced by Exparel®. CONCLUSIONS: Perineural or systemic dexamethasone had a protective effect against the neural inflammation induced by bupivacaine, and perineural dexamethasone attenuated delayed inflammation induced by perineural Exparel®.

Results of scaphocapitate arthrodesis with lunate excision in advanced Kienböck disease at 10.7-year mean follow-up.

Scaphocapitate arthrodesis with lunate excision was performed for treatment of advanced Kienböck disease in 17 patients (18 wrists). Ten were women and seven men. Five were Lichtmann Stage IIIA, 12 Stage IIIB, and one Stage IV. Minimum follow-up period was 24 months; mean follow-up was 10.7 years (range 2.3 to 22 years, SD 7.1). At the latest follow-up, six patients were very satisfied, nine were satisfied and two were disappointed. Pain was significantly decreased in all cases. Wrist mobility was unchanged. Grip strength was significantly increased. Consolidation of the arthrodesis was confirmed in 17 wrists. We encountered a scaphocapitate nonunion at 12 years follow-up and two cases of styloscaphoid arthritis at 17 and 22 years. Scaphocapitate arthrodesis with lunate excision performed in an advanced stage of Kienböck disease significantly alleviates pain, while preserving functional mobility and satisfactory grip strength in the long term. LEVEL OF EVIDENCE: IV.