Penthrox® (Methoxyflurane) as an Analgesic for Removal of Circular External Fixators and Minor Procedures during the COVID-19 Pandemic.

Introduction: Methoxyflurane has excellent analgesic properties and is approved for use in the United Kingdom and Ireland since 2015. It is currently used in emergency departments for analgesia during fracture reductions. During the COVID-19 pandemic, with theatre access severely restricted, Penthrox® had the potential to provide adequate pain relief to aid frame and wire removal in the clinic setting. Materials and methods: Patients presenting to the limb reconstruction service elective clinic and requiring frame removal or minor procedures were included in the study. Patients with renal, cardiac or hepatic disease, a history of sensitivity to fluorinated anaesthetic agents and those on any nephrotoxic or enzyme-inducing drugs were excluded. All procedures were performed in an appropriate isolated room in the clinic. Patient demographics, procedure details, visual analogue score, Richmond Agitation Scale and patient satisfaction were recorded. Results: A total of 39 patients were included in the study of which 17 had Ilizarov frames removed, 10 had hexapod removals, nine had heel rings removed and three had an external fixator removed. Eleven patients received additional pain relief in the form of oral analgesia. All patients were satisfied or very satisfied with the experience. One patient required a general anaesthetic for the removal of a wire that could not be removed in the clinic due to bony overgrowth. Conclusion: Patient satisfaction was very high (>95%), and it was possible to perform frame removals and minor procedures in the clinic environment during the COVID-19 pandemic. We see potential for regular use of Penthrox® in the future for the removal of external fixation outside of the operating theatre. Clinical significance: Penthrox as an analgesic for frame adjustments and removals is safe and has the potential for significant financial savings for the National Health Service (NHS). How to cite this article: Debuka E, Birkenhead P, Shah S, et al. Penthrox® (Methoxyflurane) as an Analgesic for Removal of Circular External Fixators and Minor Procedures during the COVID-19 Pandemic. Strategies Trauma Limb Reconstr 2023;18(2):82-86.

Circular frames without x-ray - lessons learned regarding radiation exposure during tibial deformity correction from Low & Middle Income Countries?

Circular frames are a successful way of treating difficult fractures and non-unions. At our institution (CSC) in Phnom Penh, Cambodia, our method differs from developed healthcare systems in that we do not use x-ray to site the frames. A retrospective cohort study was performed between CSC and a UK LRS unit. Demographics, diagnosis, frame type, pre- and post-op deformity, proximal and distal construct alignment comparative to the tibia, and time to union or failure. 70 patients in total were identified and were randomly selected from a hospital in UK. Demographics & deformity were similar and failed to reach significant difference on testing: union rate 70% v. 82%, time to union 9.8 v. 8.5 months, and radiation exposure mean 0 v. 74 cGy/cm2 (range 6.4-326.7). These are startlingly homogenous results considering the differing resources available. We believe that ring fixators are a viable treatment method in austere environments where image intensifiers are unavailable, and demand no unnecessary radiation exposure.

The role of fracture reduction and plate position in the aetiology of flexor pollicis longus tendon rupture after volar plate fixation of distal radius fractures.

BACKGROUND: Flexor pollicis longus (FPL) rupture has been described as complication following volar plating for distal radius fractures. It has been hypothesised that this is due to plate prominence. The aim of the study was to investigate the relationship between sub-optimal plate position and fracture reduction on plate prominence. METHODS: Plate prominence was measured in two experimental models. In the first, the effect of plate position was investigated using 18 fresh frozen cadavers with prominence being measured using a micrometer. In the second study, the effect of fracture reduction on plate prominence was investigated using similar methodology with simulated mal-reductions on dry bone models. RESULTS: The results of the first study showed a significant increase in lift-off for three plates (DVR, Synthes Universal and Acu-Loc), if the plates were moved distally or proximally from the anatomical position. Similar increases in prominence were also seen with rotational mal-positions. The results of the second study showed a statistically significant effect on plate prominence for even a 5° mal-reduction (p = 0.001) with worsening lift-off with increasing mal-reduction. These changes are significantly different from baseline and also significantly different to the lift-off recorded with mal-reductions 5° better and worse. Mal-reductions also necessitate more proximal placement of the plate to avoid screw penetration of the articular surface, and each 5° increment is significantly different from baseline. CONCLUSIONS: The results show a statistically and clinically significant effect of both plate position and fracture reduction on plate prominence and support the theory that both contribute to the aetiology of post-operative FPL rupture.