Exercise as it relates to Disease/Exercise prescription post hospitalization for minor diabetes-related amputations to avoid re-amputation

This Wikibooks page is a critical appraisal of the journal article "Re-amputation in patients with diabetes-related minor amputations who underwent physical therapy during their hospitalization" by Imaoka et al., (2021).

What is the background to this research?
The rapid increase in diabetes is a world-wide problem. Unmanaged diabetes rapidly leads to a cascade of multi-system pathological processes frequently resulting in foot lesions and in the worst-case amputation. A foot lesion alters a person’s ability to participate in activities which are meaningful to them as well as the levels of physical activity needed to manage the condition. Currently there is little research into the risk factors for re-amputation for patients who participated in physiotherapy after their amputation. Imaoka et al., aimed to add knowledge around modifiable risk factors to guide physiotherapy management to reduce the risk of further re-amputation, ie. another amputation of digit or foot bone, and maintain patient quality of life as high as possible.

Where is the research from?
This research was conducted in Japan and published in the well-respected Journal of Foot and Ankle Research in 2021. In this research team, Koji Sato has the most publications, translated into multiple respected journals.

Rates of Type 2 diabetes and impaired glucose tolerance were approximately 13.5% in 2009 in Japan and Australian rates were 8.2%. Australian numbers could be underestimated by as much as 30% indicating both countries are facing large numbers of people with increased risk of limb-loss if left unmanaged.

The research group reported no conflicts of interest.

What kind of research was this?
Imaoka et al., conducted a single-centre retrospective cohort study, recruiting 245 consecutive in-patients coming through the Wound Care Centre of Oita Oka Hospital between 2015 and 2018. Patients received physiotherapy during their hospital stay after revascularization or minor amputations. After exclusion criteria were met, 129 patients were enrolled. Retrospective cohort studies, while commonly used for risk-factor analysis for medical conditions, have disadvantages including lacking ability to pose new research questions, relying on already collected data, possibly with large variability in measurement. Participants were consecutively selected minimizing the risk of selection bias.

What did the research involve?
All diabetic patients who were hospitalized for damage to the sole of their foot requiring amputation of toes or other foot bones, were included in the study. These patients received physiotherapy after their amputation and had regular follow-ups at 1,3, 6 or 12 months in the 1 year following discharge from hospital.

Prior to discharge multiple measures were collected, including patient’s physical function as measured by thigh strength, ankle range, sensation at the foot and the patient’s ability to walk.

Patients were excluded from the study if they fit any of the following categories; post-amputation infection, major amputation (below or above the knee), did not return to appointments, limited cognition or use of wheelchair prior to amputation. High exclusion criteria aim to limit factors which might confound the study's results. For instance, participants with increasing dementia were excluded from the study as they might forget weightbearing instructions or wound care guidelines, therefore the conclusions from the study can be applied with caution to a person with dementia.

What were the basic results?
32.5% of the patients required re-amputation within one of year of discharge from hospital which is similar to previous studies in Japanese populations. Three factors were found to significantly increase the risk of re-amputation.

-      Need for haemodialysis increased risk, hazard risk (HR) of re-amputation by 2.2 times.

-      A higher Functional Independence Measure (FIM), HR of 3.85

-      Reduced dorsiflexion, HR of 5.82.

In their discussion Imaoka et al debate the reasons behind those modifiable risk factors and their increased risk of re-amputation, concluding by acknowledging limitations and need for further research.

What conclusions can we take from this research?
Previous recommendations for weightbearing status for diabetic foot, exercise and risk factors for further foot lesions have changed significantly over the past 10 years. Until recently, diabetic foot guidelines discouraged any activities increasing pressure through the foot. Physical activity levels are known to be lower in diabetic populations than non-diabetic, and decrease further after the first amputation. Clinicians become more risk-averse regarding activity recommendations perpetuating low levels of physical activity. This study offers quick and practical measures for clinicians, both during their hospital stay and after discharge.

Physical activity and exercise are now cornerstones in diabetes management and the ability to complete a risk-analysis for tailored advice and exercise prescription is crucial. Measuring ankle range and ability to walk are simple and validated tests health professionals can complete without expensive equipment.

A higher FIM score was associated with increased risk of re-amputation. Walking with limited dorsiflexion increases plantar tissue stress, an independent risk factor for re-amputation.

Practical advice
Regular range of motion screening post-discharge should be a mainstay in diabetic populations due to the strong link between limited dorsiflexion and abnormal gait. In this study change in range between groups occurred around the 65-day post discharge mark. As such, regular range of motion screening post discharge has the potential to facilitate ongoing gait, normalising pressures through the foot. This would control one modifiable risk factor for ulceration and consequently re-amputation.

During a period when a diabetic has reduced ankle range modification of weightbearing lower limb activity to cycling and open chain lower limb strength training can maintain glycaemic control, counter catabolic changes and reduce load on the renal system while reducing ulceration risk. Targeted physiotherapy around the ankle can increase range concurrently. Rapid changes in activity intensity and volume have been found to increase risk of foot ulcerations. Therefore it is essential to program using progressive overload principles to ensure increases the health of the tissue are done safely.

Weightbearing exercise in a diabetic populations is feasible and efficacious while non-weightbearing exercise add value through improving HbA1c levels to a greater degree. There is strong evidence to guide exercise professionals working with diabetic clients’ regarding importance of different exercise, both resistance and aerobic and the utility of both weightbearing and non-weightbearing modalities. Additionally, evidence emphasises the importance of monitoring training volume and distribution over time to avoid compromising skin integrity.

When lesions occur, it is essential to avoid activity pressuring or stretching the area. It is always the professional's responsibility to ensure the patient understands skin integrity is crucial and exercise must be modified during a period of healing. Non-weightbearing exercise has been found to improve healing rates in diabetic populations compared to no exercise. Enhanced healing effects are attributed primarily to increased blood flow.

Excellent communication skills are required for education to be meaningfully received by the client. This includes the importance of keeping active in a safe way during the healing period of any lesion.

Further information/resources
Resources directed at the professional

ADA Position Statement of Physical Activity and Exercise

2019 IWGDF Guidelines

Burden of Diabetes in Australia 2018

Resources to help you manage your diabetes

Diabetes Feet Australia

FootForward Program