SLR - June 2015 - Nicole Byerley

Outcome of One-Stage Correction of Deformities of the Ankle and Hindfoot and Fusion in Charcot Neuroarthropathy Using a Retrograde Intramedullary Hindfoot Arthrodesis Nail

Reference: Siebachmeyer, M, Boddu K, Bilal A, Hester TW, Hardwick T, Fox TP, Edmonds M, Kavarthapu V. Outcome of one-stage correction of deformities of the ankle and hindfoot and fusion in Charcot neuroarthropathy using a retrograde intramedullary hindfoot arthrodesis nail. Bone Joint J. 2015 Jan;97-B(1): 76-82.

Scientific Literature Review

Reviewed By: Nicole Byerley, DPM
Residency Program: Southern Arizona VA Health Care Systems

Podiatric Relevance: Ulcers, loss of ability to ambulate and, ultimately loss of limb are common consequences of patients with deformity due to Charcot neuroarthropathy.  In dealing with neuropathic patients, it is important to develop knowledge of treatment options for patients with severe Charcot hindfoot deformity and the relative success of the procedure to return the foot to a plantigrade position.

Methods: Between January 2008 and April 2013, 20 patients (21 feet total) with Charcot Neuroarthropathy (CN) were identified that underwent ankle and hindfoot reconstruction. All patients were taken through a treatment algorithm that assessed the deformity’s stability, the presence of ulcers and infection, presence of PVD, level of deformity and acute/chronic disease state.  Acute CN was treated with total contact casts until the swelling and the temperature differences were normalized. Infected ulcers were treated with debridement, IV antibiotics and negative pressure therapy. Of the 20 patients, 13 were DM type II, one was DM type I, and one was non diabetic. Hemoglobin A1c ranges were from 5.2 percent to 11.3 percent. Ulcerations (chronic and recurrent) were noted in 15 patients total with 11 of the patients having ulceration at the time of surgery.

All patients in the study were surgically treated using a hindfoot arthrodesis nail by a single surgeon using a standard surgical technique. The deformity was corrected by resecting a wedge of bone through a single incision on the convex side of the deformity. Standard screws were replaced by hydroxyapatite- (HA) screws during the early portion of the study due to migration of the standard screws in two patients.  The concept of a “superconstruct” was used for fixation with care taken for the hardware to extend beyond the levels of the Charcot deformity. Patients with a midfoot deformity were also treated with a coinciding midfoot fusion with bolt and/or locking plate.  Patients were required to be non-weightbearing for at least three months initially and then transitioned to partial weightbearing for three months. Radiographic assessment was utilized to assess transition to weightbearing with removable bracing and then ambulation with lace-up shoes or custom foot gear. The study also assessed placement of screws immediately post-op versus six months post-op to determine screw migration. Pre and post operatively, patient satisfaction was evaluated with three questionnaires including: the American Academy of Orthopedic Surgeons Foot and Ankle Outcomes (AAOS-FAQ), Short Form (SF)- 36 Health Surgery, and the Euroqol EQ-5D-5L. Additionally, limb salvage rates, full weightbearing ability, ulcer status, fusion, and need for surgical revisions were recorded for assessment.

Results: All 21 feet in the study underwent hindfoot deformity correction and tibiocalcaneal fusion using the IM hindfoot fusion nail with seven patients additionally requiring a midfoot fusion and two patients undergoing 1st MTPJ fusion. The mean follow up to the study was 26 months (8-54 months). All patients (100 percent) had limb salvage at follow up. All three questionnaires revealed improvement in patient satisfaction and function. Of the 15 patients with ulcers, 12 patients demonstrated total healing with the procedure. All patients but one achieved full weightbearing status with proper shoe gear (four feet required custom AFOs and two feet required pneumatic walking brace). Fusion was noted radiographically in 19 out of 21 of feet. Of the other two patients, one fusion failed and another patient had a stable, painless pseudoarthrosis. Two patients required removal of the nail due to complications with the nail failing and breaking in one patient and the other requiring removal due to ulceration on the plantar foot in close proximity to the nail. It was noted that three patients required the proximal locking screws to be removed to increase dynamics of the nail and enhance fusion. Four of 22 standard distal locking screws (in two patients) migrated while none of the 34 HA coated locking screws had noted migration.

Conclusions: The current study’s single-stage reconstruction and internal fixation in patients with severe Charcot ankle and hindfoot deformity can achieve healing of chronic ulceration, ambulation with proper shoe gear, limb salvation and improve patient’s measure of satisfaction and function.

Previous studies addressing surgical reconstruction have noted 100 percent limb salvage rates and a 77.8 percent fusion rate in CN patients without ulceration. Prior studies addressing similar patients with chronic ulceration have demonstrated poorer results with limb salvage (82.0 percent to 95.2 percent) and fusion rates (90.5 percent).The current study’s results demonstrate 100 percent limb salvage in a subject population that 71 percent of patients had chronic ulceration and 52 percent of the patients had ulcers at the time of reconstruction. The questionnaire results and the weightbearing status of the patients demonstrate satisfactory function. Ulceration at time of surgery with the technique cited in the article does not seem to be a contraindication for reconstruction with IM nail.

In the study, correction of deformity with proper wound management and offloading offered an 80 percent rate of ulcer healing. External fixation is another method in the literature noted as an alternative to IM fixation.  Recent studies have reported healing of ulcerations at a rate of 62 percent, limb salvage at a rate of 89.0 percent to 95.7 percent, and a 73 percent rate of boney fusion. The current study demonstrates similar or better results than those rates reported with use of external fixation. Additionally, the one stage correction avoids the complications that are reported with external fixation such as pin tract infections, poor compliance, psychological impact and need for multiple surgeries.

Durability of fixation in CN reconstruction is at the utmost importance. In this study, the HA coated locking screws were used to replace the standard locking screws after analysis of migration that was demonstrated by the standard screws at six months post-op. The superior fixation of HA locking screws demonstrated in the study should be considered when choosing surgical fixation for CN reconstruction.

There were several limitations to the study including no randomized control group and a relatively small patient population. However, the results of the study support performing a one stage reconstruction of the hindfoot and ankle in patients with Charcot deformity with chronic ulceration. The technique can be considered as another option for surgical intervention offering patients a future ability for ambulation, increased satisfaction, and limb salvage. 

Educational Opportunities