Clinical Comparison of Internal Fixation Constructs in Midfoot Charcot Arthropathy

Abstract

Category: Diabetes; Midfoot/Forefoot Introduction/Purpose: Midfoot Charcot can lead to instability, deformity and ultimately ulceration that can be limb threatening. Previous authors have described a variety of surgical stabilization techniques and constructs including intramedullary fixation (“beaming”) across the midfoot in varying orientations. More recently, intramedullary compression nails (“IM nail”) have been introduced. In contrast with static screws, these devices provide compression across the joints of the midfoot by engaging a compression mechanism against a fixed interlock screw. To our knowledge no clinical comparison between traditional beaming techniques and modern compression nails for midfoot Charcot has been reported. We hypothesize that using IM nails will result in a higher union rate, and lower reoperation and hardware failure rates. Methods: Our electronic medical record was queried to identify patients from 2016-2021 who underwent midfoot reconstruction. Only patients with midfoot Charcot who underwent extended intramedullary fixation were included. Patients with active ulceration at the time of surgery, Charcot that included the ankle, or external fixation as part of the construct were excluded. IM nails were used exclusively for medial column constructs. Basic demographic information was collected. Radiographs and operative notes were evaluated and construct type and implants used were noted. Radiographs at final follow-up were evaluated for union and hardware complication. Clinical notes were evaluated for weightbearing status, plantigrade foot position, ulceration, and wound care requirements. Finally, all complications and reoperations were recorded. Chi-squared or Fisher’s Exact tests were used as appropriate to compare categorical variables and t-tests were used to compare numerical variables. Results: 48 feet (47 patients) with a median age of 58 years (IQR 50, 64) were included. Diabetes was the Charcot etiology in 34/48 (70.8%) feet. There were 19 beaming and 29 IM nail constructs. Basic demographics and Brodsky classification were equally distributed (p>0.05). Median follow-up time was 1.3 years (IQR 0.8, 2.9). Combined medial and lateral column fixation was performed in 39/48 (81.3%) patients. 52% (25/48) included subtalar arthrodesis. Beaming constructs had higher re-operation rates (57.9% versus 27.6%, p < 0.05), and higher hardware failure rates (57% versus 6.9%, p< 0.001). IM nail group had higher union rates (75.9% versus 31.6%, p = 0.001), and higher rates of full weight-bearing at final follow up (86.2% versus 68%, p < 0.05). Two (4.2%) patients required amputation. Conclusion: In a cohort of 48 feet undergoing midfoot Charcot reconstruction, the use of medial column IM nails was associated with lower reoperation rates, lower rates of hardware failure, higher union rates, and higher rates of full weightbearing at final follow-up compared with traditional screw fixation. Surgeons who treat midfoot Charcot may consider these results when planning their stabilization constructs in this high-risk patient population.