Risk of Ipsilateral Reamputation Following an Incident Toe Amputation Among U.S. Military Veterans With Diabetes, 2005-2016

Association of remoteness and ethnicity with major amputation following minor amputation to treat diabetes-related foot disease

INTRODUCTION

Minor amputation is commonly needed to treat diabetes-related foot disease (DFD). Remoteness of residence is known to limit access to healthcare and has previously been associated with poor outcomes. The primary aim of this study was to examine the associations between ethnicity and remoteness of residency with the risk of major amputation and death following initial treatment of DFD by minor amputation. A secondary aim was to identify risk factors for major amputation and death following minor amputation to treat DFD.

RESEARCH DESIGN AND METHODS

This was a retrospective analysis of data from patients who required a minor amputation to treat DFD between 2000 and 2019 at a regional tertiary hospital in Queensland, Australia. Baseline characteristics were collected together with remoteness of residence and ethnicity. Remoteness was classified according to the 2019 Modified Monash Model (MMM) system. Ethnicity was based on self-identification as an Aboriginal and Torres Strait Islander or non-Indigenous person. The outcomes of major amputation, repeat minor amputation and death were examined using Cox-proportional hazard analyses.

RESULTS

A total of 534 participants were included, with 306 (57.3%) residing in metropolitan or regional centres, 228 (42.7%) in rural and remote communities and 144 (27.0%) were Aboriginal or Torres Strait Islander people. During a median (inter quartile range) follow-up of 4.0 (2.1-7.6) years, 103 participants (19.3%) had major amputation, 230 (43.1%) had repeat minor amputation and 250 (46.8%) died. The risks (hazard ratio [95% CI]) of major amputation and death were not significantly higher in participants residing in rural and remote areas (0.97, 0.67-1.47; and 0.98, 0.76-1.26) or in Aboriginal or Torres Strait Islander people (HR 1.44, 95% CI 0.96, 2.16 and HR 0.89, 95% CI 0.67, 1.18). Ischemic heart disease (IHD), peripheral artery disease (PAD), osteomyelitis and foot ulceration (p<0.001 in all instances) were independent risk factors for major amputation.

CONCLUSION

Major amputation and death are common following minor amputation to treat DFD and people with IHD, PAD and osteomyelitis have an increased risk of major amputation. Aboriginal and Torres Strait Islander People and residents of remote areas were not at excess risk of major amputation.

Comparison of Two Techniques for Proximal Margin Analysis of Toe Amputations: A Retrospective Review

Toe amputations are a common podiatric procedure for treatment of osteomyelitis. Whether or not the surgeon obtains a surgical cure, thus resolving the infection, can be difficult to assess. Obtaining a proximal bone margin can assist the treatment team in deciding the duration of postoperative antibiotics, need for reoperation, and postoperative care. The two senior surgeons use different methods to analyze proximal bone margins. The first surgeon obtains a microbiologic culture from the remaining bone, either at the proximal phalanx or metatarsal head, following the removal of the toe to be reviewed for osteomyelitis. Per the second surgeon's technique, the pathologist only analyzes the proximal aspect of the amputated toe for presence of osteomyelitis. Our goal is to analyze the reoperation and reamputation rates between the techniques in which the proximal margin specimens are obtained. A retrospective chart review was performed on all isolated toe or partial toe amputations from March 2017 to September 2022. There were 115 patients who met inclusion criteria. Reoperation and reamputation rates were analyzed for positive and negative infection margins from intraoperative cultures. Our study found an overall 28% reoperation rate and 26% reamputation rate for the negative margins group. In the positive proximal margin group, there was an overall 48% reoperation rate and 44% reamputation rate. Our analysis did not find a statistically significant difference between the reamputation rate in the negative margins group and the reamputation rate in the positive margins group. In conclusion, our study found that a positive proximal margin for osteomyelitis exhibited a nearly double reoperation and reamputation rate compared to patients with a negative margin, and that one margin analysis technique was not inferior to the other in regards to the need for additional surgeries.

Comorbidity and risk factors of subsequent lower extremity amputation in patients diagnosed with diabetes in Saskatchewan, Canada

OBJECTIVE

Subsequent limb amputation (SLA) may be necessary due to disease progression, infection, or to aid prosthesis fit. SLA in Saskatchewan has increased 3.2% from 2006 to 2019 with minor SLA increasing 9.6% during that period. Diabetes affects a large proportion of patients who require SLA; however, the impact of additional comorbidities is not clear.

METHODS

First-episode subsequent lower extremity limb amputation (SLEA) cases with the presence/absence of diabetes, other comorbidities, and demographic characteristics from 2006-2019 were retrieved from Saskatchewan's Discharge Abstract Database. Logistic regression was performed to examine the magnitude of the odds of SLEA.

RESULTS

Among the 956 first-episode SLEA patients investigated, 78.8% were diagnosed with diabetes. Of these, 76.1% were male and 83.0% were aged 50 + years. Three comorbidities: renal failure (AOR = 1.9, 95% Cl 1.1 - 3.0), hypertension (AOR = 3.0, 95% Cl 2.0 - 4.5), and congestive heart failure (AOR = 2.0, 95% CI 1.2 - 3.2), conferred the highest odds of SLEA. The odds of SLEA is greatest for those aged 50-69 years, males, Registered Indians, and associated with a prolonged hospital stay.

DISCUSSION

These data are important as they may help medical providers identify patients at the highest risk of SLEA and target interventions to optimize outcomes.

Compensatory gait mechanics in person with multiple toe amputation: A single case report

This case highlights the biomechanical influence of toe amputation on contralateral limb force elevation, possibly through reduced ipsilateral plantar flexor torque production. These findings provide insight into toe amputation-related compensatory gait mechanics with greater inter-limb asymmetry, which may increase the risk of musculoskeletal comorbidities, including osteoarthritis in contralateral limb.

AMPREDICT PROsthetics-Predicting Prosthesis Mobility to Aid in Prosthetic Prescription and Rehabilitation Planning

OBJECTIVE

To develop and validate a patient-specific multivariable prediction model that uses variables readily available in the electronic medical record to predict 12-month mobility at the time of initial post-amputation prosthetic prescription. The prediction model is designed for patients who have undergone their initial transtibial (TT) or transfemoral (TF) amputation because of complications of diabetes and/or peripheral artery disease.

DESIGN

Multi-methodology cohort study that identified patients retrospectively through a large Veteran's Affairs (VA) dataset then prospectively collected their patient-reported mobility.

SETTING

The VA Corporate Data Warehouse, the National Prosthetics Patient Database, participant mailings, and phone calls.

PARTICIPANTS

Three-hundred fifty-seven veterans who underwent an incident dysvascular TT or TF amputation and received a qualifying lower limb prosthesis between March 1, 2018, and November 30, 2020 (N=357).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The Amputee Single Item Mobility Measure (AMPSIMM) was divided into a 4-category outcome to predict wheelchair mobility (0-2), and household (3), basic community (4), or advanced community ambulation (5-6).

RESULTS

Multinomial logistic lasso regression, a machine learning methodology designed to select variables that most contribute to prediction while controlling for overfitting, led to a final model including 23 predictors of the 4-category AMPSIMM outcome that effectively discriminates household ambulation from basic community ambulation and from advanced community ambulation-levels of key clinical importance when estimating future prosthetic demands. The overall model performance was modest as it did not discriminate wheelchair from household mobility as effectively.

CONCLUSIONS

The AMPREDICT PROsthetics model can assist providers in estimating individual patients' future mobility at the time of prosthetic prescription, thereby aiding in the formulation of appropriate mobility goals, as well as facilitating the prescription of a prosthetic device that is most appropriate for anticipated functional goals.

Does a shorter residual first metatarsal length after first ray amputation in diabetic patients leads to poorer outcomes - A risk factor study

BACKGROUND

The first ray plays a vital role in the normal function of the foot and the gait cycle where in its absence can lead to abnormal changes in weight distribution to the residual first metatarsal stump and lesser metatarsals with predisposition to developing lesser toe deformities reulcerations and reamputations particularly in diabetic patients. This study aims to characterise the outcomes after first ray amputation and its associated risk factors with focus on the impact of residual first metatarsal length.

METHODS

All diabetic patients with first ray amputations from January 2012 to December 2016 were reviewed. Residual first metatarsal length was measured using postoperative radiographs. Risk factors for outcomes such as readmission, reulceration and/or reamputation, transfer ulceration and/or amputation of lesser toes, proximal amputations, ulcer-free duration (UFD) and mortality were analysed using bivariate logistic/linear regression followed by multiple logistic/linear regression models adjusting for confounding factors.

RESULTS

Among 89 patients with first ray amputations, 65.3 % needed readmission for further treatment. Although only 10.1 % had reulceration at the first ray which all led to reamputation, there were 56.2 % with transfer ulceration and 40.4 % with transfer amputation of the lesser toes in this cohort. The prevalence of transmetatarsal amputation was 18 % and proximal amputations at 12.4 % while the average UFD was 27 months. Mortality rate was 31.5 % with an average of 3-year survival. Preservation of the first metatarsal length via metatarsophalangeal joint disarticulation independently reduced likelihood of readmissions and residual metatarsal length of > one third when compared to < one third after first ray amputations had lower likelihood of transfer amputation of lesser toes.

CONCLUSION

First ray amputation in diabetic patients leads to significant morbidities and mortality. Preservation of the residual first metatarsal length independently reduced the likelihood of readmissions and transfer amputation to the lesser toes.

Analysis of repeated lesions after diabetic forefoot amputation

AIM

This study was performed to analyze the clinical characteristics, related factors, and prognosis of repeated lesions after diabetic forefoot amputation.

METHODS

The medical records of 998 patients who underwent forefoot amputation because of their diabetic feet from March 2002 to February 2021 were retrospectively analyzed. Of the 508 selected patients with a follow-up period of at least 6 months, 288 had repeated lesions in the forefoot, and 220 did not have repeated lesions. The related factors of repeated lesions were compared and analyzed. Of the patients with repeated lesions, 142 and 104 on the ipsilateral and contralateral sides, respectively were also compared and examined.

RESULTS

Repeated lesions were statistically significant in diabetic polyneuropathy, vascular calcification, and dialysis. However, the anatomical positions of diabetic foot lesions, causes of lesions, anatomical amputation levels, number of surgeries, and management duration had no significant differences. Contralateral lesions occurred 8 months later than ipsilateral lesions, but reamputation above the Lisfranc joint was more frequent and prognosis was poorer.

CONCLUSIONS

Repeated lesions were affected by general conditions, and the contralateral side must be carefully examined after diabetic forefoot amputation.

Reoperation, reamputation, and new ulceration following complete or partial toe amputation among diabetic and non-diabetic patients

AIMS

To compare the number of reoperations, reamputations, and new ulcers following toe amputation in diabetic and non-diabetic patients with sub-group analysis on index amputation level.

METHODS

One-hundred sixteen patients with a complete (CTA) or partial (PTA) toe amputation and minimum of 12-month (12 M) follow-up were identified in electronic medical records. The number of reoperations and reamputations, number and location of new ulcers, and final amputation level of the ipsilateral extremity were compared between diabetic and non-diabetic patients and between those with CTA and PTA at 12 M and final follow-up (FFU).

RESULTS

Diabetic patients had significantly more reoperations, reamputations, and new ulcers than non-diabetic patients at 12 M and FFU. There were no differences in reoperations, reamputations, or new ulcer location between CTA and PTA; however, patients with PTA developed more new ulcers at 12 M and FFU and were more likely to have a distal final amputation level compared to those with CTA.

CONCLUSIONS

Diabetic patients required significantly more reoperations and reamputations following a toe amputation and developed more new ulcers than non-diabetic patients regardless of index amputation level. These high rates among diabetic patients highlight the complications encountered following toe amputation and emphasize the need for close, multi-disciplinary care.

Re-amputation and survival following toe amputation: outcome data from a tertiary referral centre

PURPOSE

Toe amputation is a commonly performed procedure for irreversible foot sepsis. However, outcome and predictors of outcome are poorly understood. Our aim was to determine survival and rate of progression to further amputation following index toe amputation.

METHODS

Consecutive patients between 2010 and 2015 were included. Progression to further minor amputation, major amputation or death was recorded. Multivariable Cox regression analyses were undertaken to determine independent predictors of outcome and survival.

RESULTS

One hundred forty-six patients were included, with mean age of 65 years. Fifty-five (37.7%) patients underwent hallux amputation, while 91 (62.3%) underwent amputation of non-hallux digit(s). Following index toe amputation, 63 (43.2%) patients progressed to further minor or major ipsilateral amputation, median time to which was 36 months. Twenty-one patients (14.4%) progressed to major ipsilateral amputation. Patients undergoing index non-hallux amputation were significantly more likely to require further minor amputation (P = 0.050); however, the rate of major amputation between hallux (14.5%) and non-hallux (14.3%) groups was similar. Overall, 5-year ipsilateral amputation-free (iAFS) was 39.6 ± 4.1%, ipsilateral major amputation-free (iMAFS) was 55.9 ± 4.1% and overall survival (OS) was 64.3 ± 4.0% and did not differ between index amputation sites.

CONCLUSION

Almost half of patients undergoing toe amputation required further digital amputation. However, limb preservation rates are high, and a majority of patients are alive at 5-year follow-up. There was no significant difference in outcome between patients undergoing hallux and non-hallux primary procedures. Overall, increasing age remains the only independent predictor of iMAFS and OS.

Lower extremity reamputation in people with diabetes: a systematic review and meta-analysis

In this study, we determined the reamputation-free survival to both limbs and to the contralateral limb only following an index amputation of any-level and assessed whether reamputation rates have changed over time. We completed a systematic search using PubMed and screened a total of 205 articles for data on reamputation rates. We reported qualitative characteristics of 56 studies that included data on reamputation rates and completed a meta-analysis on 22 of the studies which enrolled exclusively participants with diabetes. The random-effects meta-analysis fit a parametric survival distribution to the data for reamputations to both limbs and to the contralateral limb only. We assessed whether there was a temporal trend in the reamputation rate using the Mann-Kendall test. Incidence rates were high for reamputation to both limbs and to the contralateral limb only. At 1 year, the reamputation rate for all contralateral and ipsilateral reamputations was found to be 19% (IQR=5.1%-31.6%), and at 5 years, it was found to be 37.1% (IQR=27.0%-47.2%). The contralateral reamputation rate at 5 years was found to be 20.5% (IQR=13.3%-27.2%). We found no evidence of a trend in the reamputation rates over more than two decades of literature analyzed. The incidence of lower extremity reamputation is high among patients with diabetes who have undergone initial amputations secondary to diabetes, and rates of reamputation have not changed over at least two decades.

How patients interpret early signs of foot problems and reasons for delays in care: Findings from interviews with patients who have undergone toe amputations

Aims

To describe how patients respond to early signs of foot problems and the factors that result in delays in care.

Methods

Semi-structured interviews were conducted with a large sample of Veterans from across the United States with diabetes mellitus who had undergone a toe amputation. Data were analyzed using inductive content analysis.

Results

We interviewed 61 male patients. Mean age was 66 years, 41% were married, and 37% had a high school education or less. The patient-level factors related to delayed care included: 1) not knowing something was wrong, 2) misinterpreting symptoms, 3) “sudden” and “unexpected” illness progression, and 4) competing priorities getting in the way of care-seeking. The system-level factors included: 5) asking patients to watch it, 6) difficulty getting the right type of care when needed, and 7) distance to care and other transportation barriers.

Conclusion

A confluence of patient factors (e.g., not examining their feet regularly or thoroughly and/or not acting quickly when they noticed something was wrong) and system factors (e.g., absence of a mechanism to support patient’s appraisal of symptoms, lack of access to timely and convenient-located appointments) delayed care. Identifying patient- and system-level interventions that can shorten or eliminate care delays could help reduce rates of limb loss.