SLR - May 2018 - Garrett A. Melick

Mid-Term Follow-Up of Patients with Hindfoot Arthrodesis with Retrograde Compression Intramedullary Nail in Charcot Neuroarthropathy of the Hindfoot

Reference: Chraim M, Krenn S, Alrabai HM, Trnka H-J, Bock P. Mid-Term Follow-Up of Patients with Hindfoot Arthrodesis with Retrograde Compression Intramedullary Nail in Charcot Neuroarthropathy of the Hindfoot. The Bone & Joint Journal 2018 February;100-B (2), 190–196.

Scientific Literature Review

Reviewed By: Garrett A. Melick, DPM
Residency Program: Cambridge Health Alliance, Cambridge, MA

Podiatric Relevance: Charcot of the ankle and hindfoot presents an area of concern for foot and ankle surgeons, as failure to achieve adequate correction may result in limb loss. In a recent 2016 JFAS systematic review, Schneekloth et al have postulated that Charcot of the rearfoot is less amenable to conservative treatment than that of the midfoot. There are variable options for fixation, thus the authors of this study sought to delineate the midterm success of retrograde intramedullary (IM) compression nailing for rearfoot Charcot with regard to radiographic parameters, function and complication rate.

Methods: This study involved a retrospective review of 18 patients (19 feet) with rearfoot Charcot with or without associated ulceration who underwent IM nail tibiotalocalcaneal (TTC) fusion. These patients all had failure of conservative therapy. Revisional rearfoot surgery patients and those with osteomyelitis were excluded, but subjects with infected ulceration or acute Charcot were included, following casting and/or antibiotic therapy. Surgical intervention involved fibular osteotomy between the middle and distal third of the fibula and retrograde IM compression nail placement with the foot plantigrade, the rearfoot in 5 degrees of valgus and the foot externally rotated 5 to 10 degrees. In all but one case, the medial portion of the distal fibula was preserved to provide a lateral buttress for the TTC construct. Adjunctive procedures were performed as needed, including TN and/or CC joint fusion, talectomy, bone grafting and first ray elevation. Postoperative course involved four weeks of nonweightbearing, four weeks of partial weightbearing and four weeks of full weightbearing in a below-knee cast with transition to orthotic boots following cast removal. Outcome measures were assessed according to AOFAS-hindfoot scale, foot function index (FFI), foot and ankle outcome score (FAOS), VAS scale, a previously validated hindfoot alignment view angle to assess for frontal angulation and radiographic union.

Results: Significant improvement was demonstrated in all scoring systems except those related to sport in the FAOS system. Frontal plane correction of varus or valgus hindfoot deformity postoperatively was statistically significant. Postoperative complications included osteomyelitis requiring below-knee amputation in three patients, screw irritation requiring screw removal in two patients, TN joint nonunion in one patient, residual rearfoot varus in one patient requiring Chopart osteotomy and delayed union requiring dynamization in two patients.

Conclusions:
The integrity of TTC hardware was noted to be stable across subjects with complications resulting only from sources external to the construct. However, it is important to note that the TTC IM nail fusion was not adequate to achieve plantigrade foot attitude in a large number of subjects, with requirement of various concomitant procedures. While I believe this article demonstrates the power of TTC fusion, I did not find any novel information provided to the current literature base for Charcot reconstruction. Additionally, the lack of detail in methodology and results make this study difficult to reproduce or expand upon. A comparative study on different rearfoot Charcot construct designs with outcome measures, including rates of reulceration, would provide important information for foot and ankle surgeons.

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