Quality of Life Improvement Following Reconstruction of Midtarsal Charcot Foot Deformity: A Five Year Follow-Up

Abstract

Background

There is increasing interest in reconstruction of diabetes-associated Charcot foot arthropathy with the goal of improving quality of life.

Methods

Twenty-four patients who completed the Short Musculoskeletal Function Assessment (SMFA) at baseline and one year following Charcot foot reconstruction were contacted and asked to complete the survey at five years following surgery.

Results

Fourteen of the 24 patients completed the SMFA preoperatively, one year following surgery and five years postoperatively. Two patients underwent below knee amputation in the interim. Improvement was noted in all domains measured by the SMFA, with a statistically significant improvement in difficulty with daily activities at five years.

Conclusion

Correction of non-plantigrade Charcot foot arthropathy results in clinically meaningful improvement in health-related quality of life at both one and five years postoperatively, including independence with daily activities. The improvement is maintained when reevaluated at five years. This supports the modern paradigm shift towards reconstruction of this deformity.

Level of Evidence: III

Introduction

A three-year observational study performed by the American Orthopaedic Foot and Ankle Society (AOFAS) Charcot Study Group demonstrated that patients with diabetes-associated Charcot foot arthropathy reported a severe negative impact on their health-related quality of life (HRQOL). The reported impairment was not improved with the then accepted accommodative bracing.¹ Several subsequent investigations concluded that bracing (i.e. Charcot Restraint Orthotic Walker, CROW) of the acquired deformity led to very unfavorable outcomes.^2-5 This finding led to the current interest in surgical correction of the acquired deformity with the goal of eliminating accommodative bracing and allowing affected patients to walk with commercially available diabetic footwear.^6-12 Most recently, reconstructive-minded surgeons in North America have strongly advocated for limb salvage procedures via surgical reconstruction of the acquired deformities.⁷

Despite the encouraging outcomes reported in the literature, there is a paucity of data examining long-term outcomes of deformity correction in this population. Specifically, few authors have reported on HRQOL or patient reported outcome measures (PROMs) after surgical reconstruction. Data published in 2018 demonstrated a quantitative improvement in HRQOL correction of deformity associated with Charcot foot arthropathy is associated with improved function and quality of life at one-year follow-up using the well accepted Short Musculoskeletal Assessment Examination (SMFA).^8,13 The goal of this investigation is to determine if these observed improvements are maintained over time.

Methods

Following approval by the Institutional Review Board, 24 patients were identified that had previously completed the SMFA instrument prior to and one year after undergoing surgical reconstruction for diabetes-associated Charcot foot arthropathy. One patient who was not able to complete the one year follow-up survey died from unrelated medical comorbidities.^3,8 Patients were contacted via mail and phone and asked to complete the SMFA at a period of five years following surgery. Informed consent was obtained. A minimum of four attempts were made to contact patients using contact information listed in the electronic medical record.

All of the patients were classified as having nonplantigrade midfoot deformities using the classification of either Schon or Brodsky.^12,14 None of the patients had either clinical or radiographic abnormalities at the level of the tibiotalar joint. Surgical correction included correction of the deformity, resection of osteomyelitis when present, and maintenance of the correction for twelve weeks with a statically applied circular external fixator.^9,15 Figure 1 shows preoperative radiographs and clinical photos as well as postoperative photographs of a representative patient.

Figure 1.

Preoperative and postoperative clinical photos and radiographs of a patient that underwent surgical reconstruction of a non-plantigrade, midtarsal Charcot foot deformity.

The SMFA has been previously utilized with reported consistency in a similar patient population.¹⁵ The SMFA is a 2-part, 46-item, self-reported health status questionnaire that can be completed by most individuals in 10 minutes. It consists of 2 indices (dysfunction and bother index) and 4 subscales (daily activities, emotional status, arm and hand function, and mobility). The dysfunction index assesses patients’ perceptions of their functional performance of various tasks on a scale of 1 (not at all difficult) to 5 (unable to do). The bother index allows patients to assess how much they are bothered by problems in broad functional areas (i.e. how much are you bothered by problems with feeling dependent on others?) on a scale of 1 (not at all bothered) to 5 (extremely bothered).¹³

Statistical Analysis

The SMFA survey raw scores were calculated using the published scoring criteria. The response to items were summated to establish scores on the dysfunction and bother indices. The scores were then standardized to range from 0 to 100 with use of the published scoring formula. Poorer function is indicated by higher scores.¹³ Descriptive statistics were utilized to analyze the differences between the preoperative and five year data for the group.

A paired t test was used to estimate the mean change in each standardized SMFA index from baseline to follow-up. Because of the small sample sizes, all conclusions were confirmed using an exact version of the nonparametric Wilcoxon signed rank test.

Results

Twenty-four patients had previously completed the SMFA survey both preoperatively and at one year following correction of Charcot foot arthropathy. One patient died in the first year due to unrelated medical comorbidities. Sixteen of the initial study patients (66.6%) were successfully contacted and completed the SMFA survey at five years postoperatively; two of the 16 had subsequently undergone amputation between one and five years postoperatively and were thus not included in this analysis. Eight patients were unable to be contacted despite multiple attempts. At the time of surgery, the average age of the initial study population was 59.7. The average hemoglobin A1c was 8.1 and the average body mass index (BMI) of the population was 37.4.

As a whole, the mean values for all variables measured in the SMFA were improved at five years when compared to the preoperative values (Table 1). On a cohort level, there was a 17-point decrease in the SMFA standardized functional index and a 3.6-point decrease in bother index between the preoperative and the five year postoperative values. Similarly, when looking at individual domains, there was a 8.7-point decrease in difficulty with daily activities, 4-point improvement in motion, and 5.7-point improvement in mobility. The arm/hand domain demonstrated minimal change, with a 1.7-point decrease at five years.

Table 1.

Short Musculoskeletal Functional Assessment Domain Scores at Baseline, One and Five Years Following Surgical Correction of Charcot Foot

	Preoperative		One Year Postoperative		Five Years Postoperative
Variables	Mean	Std. Dev.	Mean	Std. Dev.	Mean	Std. Dev.
Function Index	97.9	23.5	80.2	26.8	80.9	22.2
Bother Index	34.2	11.3	27.0	10.1	30.6	9.6
Daily Activities	35.7	11.1	27.3	11.2	27.0	10.0
Emotion	19.7	4.3	15.5	4.6	15.7	5.9
Mobility	28.6	7.0	24.6	8.0	22.9	7.5
Arm/ Hand	13.6	5.7	12.9	6.3	11.9	4.0

N = 24 at baseline and one year, N = 14 at five years

A Wilcoxon Rank Test was performed to evaluate differences between the SMFA domains at baseline and five years. There was a statistically significant difference between the Daily Activity index at baseline and 5-year follow-up (p = 0.037, 95% confidence interval 0.7 to 16.6). All other domains assessed by the SMFA demonstrated improvement between the two time periods as listed in table 1, but did not reach significance due to the limited sample size (Table 2).

Table 2.

Change Short Musculoskeletal Functional Assessment Domain Scores at Five Years Following Surgical Correction of Charcot Foot

Variable Difference	Mean Score Change	Standard Deviation	P Value	Confidence Interval
				Lower 95%	Upper 95%
Function	-11.6	30.7	0.182	-6.2	29.3
Bother	-1.1	11.2	0.709	-5.3	7.6
Activity	-8.6	13.8	0.037	0.7	16.6
Emotional	-2.3	7.5	0.273	-2.0	6.6
Mobility	-3.8	10.6	0.206	-2.4	9.9
Arm/Hand	0.4	4.3	0.716	-2.9	2.1

N = 14 for all pairwise associations; decreasing score associated with improved outcome

Discussion

Surgical reconstruction of the acquired deformity associated with diabetes-related Charcot foot arthropathy is now well accepted among reconstructive-minded Orthopaedic Foot and Ankle Surgeons. It appears that favorable clinical outcomes are achieved when patients are freed from encumbering accommodative orthoses and can safely walk with commercially available diabetic footwear.^6-12,15 We specifically chose patients with simple midfoot deformity as these are the patients that most commonly undergo corrective surgery and the most likely to achieve favorable clinical outcomes.¹⁶

Our population demonstrated a clinically significant improvement in all domains of the SMFA between baseline preoperative and five year postoperative measurements. There was a statistically significant improvement in difficulty with daily activities. This domain asks patients to rate their difficulty with tasks such as shopping, driving, housework, yardwork, and leaving home independently. In the pursuit of improving the quality of life in patients with Charcot foot arthropathy, the ability to perform these tasks is of immense importance to independent living.

There are several limitations to this investigation. The most obvious is the small sample size. We also were not able to contact eight of the original 24 patients. Two of the patients had subsequently undergone an amputation between one and five years postoperatively and thus were not included in this analysis. A portion of our patients included in the initial study were out-of-state and ultimately were lost to follow up. We did not have any record of additional deaths in the study population, however this must be considered given the complexity of medical comorbidities in this population. Given the small sample size, we were able to observe improvements in all domains of the SMFA but only the measure of daily activity was statistically significant. Finally, the SMFA relies on patient-reported outcomes which can be subject to bias. Comparing these outcomes over three separate time points does help to mitigate the subjective nature of PROMs.

Despite the rise in acceptance of this reconstructive procedure, there is a limited amount of data on clinical outcomes in these patients. A systematic review of surgical reconstruction in Charcot neuroarthropathy evaluated 1116 feet that were reconstructed using a variety of techniques over a 15-year period. Of these patients, bone fusion was reported at 86.1% and 91% had returned to ambulation. Only six of the 42 studies representing 0.07% of patients included in the review utilized patient reported outcome measures (PROMs).¹⁷ The results of this investigation add to the growing body of literature that supports a meaningful clinical improvement in this population following surgical reconstruction. More specifically, our results suggest that the reported improvement in HRQOL as assessed by the SMFA previously observed at one year postoperatively appears to be maintained over a period of five years.

The intent of the study is to evaluate whether the improvements noted at one year postoperatively were maintained at five years postoperatively. Our results suggest that these patients do experience a clinically meaningful improvement in their quality of life and independence after surgical reconstruction of a plantigrade foot. This information offers assistance in counseling this medically complex patient population on treatment options. Further investigation including more complex deformities involving the tibiotalar joint is warranted.