MetaMet: Bone Cutter Versus Bone Saw for Ray Amputation (MetaMet)

March 26, 2023 updated by: Megan Power Foley, University College Hospital Galway

Randomised Controlled Trial Comparing Metatarsal Method of Transection Using Bone Cutters or Bone Saw on Outcomes After Ray Amputation (MetaMet)

Toe amputation is a commonly performed operation for infection and/or ischaemia (tissue death due to lack of blood flow). However, a large number of patients having this surgery ultimately require further amputation due to poor wound healing, new infections and/or new ulcers. Research to date has focused on patient-related factors associated with poor wound healing (e.g. diabetes, lack of blood flow, poor kidney function). However, there is no research looking at the technical surgical aspects of the procedure, specifically how the toe bone is cut.

For this feasibility study, we will recruit forty patients whom a consultant vascular surgeon has decided requires amputation of one-to-two adjacent toes. The participants will be randomised by a computer model into one of the two metatarsal transection methods (bone cutters or bone saw) and the rest of the procedure will be carried out in the standard fashion. Patients and assessors will be blinded to which transection method is chosen.

Patients will undergo a post-operative foot x-ray to assess for bone fragments within 48 hours of surgery and another at six months to assess for bone healing. Patients will be asked to rate their pain in the post-operative period using the verbal rating score. Patients will be followed after discharge from hospital by their public health nurse, as is standard practice, with regular follow-up in the surgical outpatients to assess wound progress. Patients will be asked to rate their quality of life at six weeks and six months post-operatively. These assessments will be coordinated with their routine post-operative follow-up clinic appointments, so as not to inconvenience patients with supernumerary visits.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Toe amputation is a common minor vascular procedure and is increasingly performed in the context of irretrievable diabetic foot infection, with and without concurrent ischaemia. Approximately 422 million people worldwide have diabetes mellitus and peripheral arterial disease (PAD) affects approximately 200 million people(1). The intersection between diabetes, neuro-ischaemic foot ulceration and lower limb amputations is well established(2). Recently published data from the United States reported overall rates of lower limb amputations in diabetic patients rose between 2000 and 2015, in part due to a 62% increase in the rate of minor (foot and toe) amputations(3). It is estimated that 6% of Irish adults are diabetic; from this, we can extrapolate the burden of managing diabetic foot complications(4). Resource utilisation notwithstanding, the financial costs of managing diabetic foot complications are estimated to outstrip some cancers(5). As the prevalence of diabetes mellitus rises amongst an ageing Irish population, the importance of achieving durable functional outcomes after partial foot amputation is paramount.

Re-ulceration, re-infection, re-amputation and hospital re-admission after partial foot amputation for digital gangrene is well documented in the literature in both diabetic and PAD cohorts(6). Across the literature, rates of re-amputation at five years post-index surgery for diabetic foot complications range from 45-65% (6, 7). A recent study by Collins et al reported that, out of 146 Irish patients undergoing minor amputations, 43% (n=63) required further ipsilateral amputation, 21 (14.4%) of which were trans-tibial or trans-femoral(8). Chronic kidney disease, diabetes with or without poor gylcaemic control, peripheral neuropathy, peripheral arterial disease, ongoing tobacco smoking, obesity (BMI >30), concurrent sepsis at the time of index operation have all been identified as independent risk factors for amputation failure and the need for revision(9-11). While numerous studies have investigated patient-dependent factors predictive of amputation failure, there is a dearth of evidence examining the impact of surgical technique on this commonly performed procedure.

An exhaustive search of the literature surrounding surgical technique and outcomes after ray amputation yielded several papers on the benefits of various soft tissue flaps for covering wound defects but just one detailing a particular methods of bone transection. However, Moodley et al focused on the use of a Gigli saw, which is beyond the scope of this feasibility study(12). There have been no randomised controlled trials evaluating the impact of metatarsal transection method on outcomes after ray amputation, specifically whether a manual bone cutter or an electric/oscillating/pneumatic bone saw were used. We hypothesise that utilising a manual bone cutter is more subject to inter-user variability, as it depends on the physical strength of the operating surgeon; improperly applied forces are liable to fracture the remaining bone, leaving small comminuted fragments that may become necrotic and act as a nidus for further infection within the wound bed. Furthermore, using an oscillating microsaw has the advantage of providing a clean bony transection regardless of the physical strength of the operator, however it may cause more damage to the surrounding connective tissues and disturb microvascular periosteal supply, which could also lead to osteonecrosis. We propose a pilot randomised controlled trial to test the feasibility and to generate sufficient data to permit sample size calculation for a trial designed to evaluate the outcomes after ray amputation using either a bone cutter or a bone saw.

Study Type

Interventional

Enrollment (Anticipated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Megan Power Foley, MRCS
  • Phone Number: 00353 871312557
  • Email: foleymp@tcd.ie

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Consenting patients, aged 18 and over, undergoing transmetatarsal amputation of one-to-two adjacent toes

Exclusion Criteria:

  • Significant peripheral arterial disease, as defined by ABPI <0.4 or digital pressures of <50mmHg, not undergoing concurrent revascularisation;
  • Patients undergoing amputation of three of more adjacent toes
  • Patients unfit for surgery;
  • Patients unable to provide informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Bone Saw
In the "intervention" arm, the metatarsal bone will be transected using an oscillating microsaw. This is an accepted surgical method.
Procedure: Bone Saw
The surgeon will use an oscillating microsaw to transect the metatarsal shaft
Other: Bone Cutter
In the "control" arm, the metatarsal bone will be transected using a manual bone cutters. This is also an accepted surgical method
Procedure: Bone Cutter
The surgeon will use a manual bone cutter to transect the metatarsal shaft

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Power Calculation for Definitive RTC
Time Frame: Six months
collect sufficient data to enable an accurate power calculation for a future randomised controlled trial
Six months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Rate of Surgical Re-Intervention
Time Frame: Six months
To determine the effect of microsaw compared to bone cutters for toe amputation on rates of surgical reintervention at the index procedure site
Six months
Rate of Hospital Re-Admissions
Time Frame: Six months
To determine the effect of microsaw compared to bone cutters for toe amputation on rates of hospital re-admissions directly related to the index surgical procedure
Six months
Time to Wound Healing
Time Frame: Six months
To determine the effect of microsaw compared to bone cutters for toe amputation on time to healing of the index surgical wound
Six months
Rate of Index Ulcer Healing
Time Frame: Six months
To determine the effect of microsaw compared to bone cutters for toe amputation on healing of the index ulcer
Six months
Rate of Re-Infection
Time Frame: six months
To determine the effect of microsaw compared to bone cutters for toe amputation on rates of re-infection at the index procedure site
six months
Rate of Ulcer Recurrence
Time Frame: Six months
To determine the effect of microsaw compared to bone cutters for toe amputation on ulcer recurrence or further ulceration
Six months
Rate of Recurrent Osteomyelitis
Time Frame: Six months
To determine the effect of microsaw compared to bone cutters for toe amputation on osteomyelitis recurrence adjacent to the index surgical site
Six months
Rate of Resection Margin Positive Culture
Time Frame: Six months
To determine the effect of microsaw compared to bone cutters for toe amputation on resection margin culture positivity
Six months
Patient-Reported Post-Operation Pain
Time Frame: Six Months
To determine the effect of microsaw compared to bone cutters for toe amputation on patient-reported post-operative pain, as measured by the Verbal Rating Scale (VRS)
Six Months
Patient-Reported Quality of Life
Time Frame: Six Months
To determine the effect of microsaw compared to bone cutters for toe amputation on patient-reported health-related quality of life at six weeks and six months, as measured by the EQ-5D-5L tool
Six Months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University College Hospital Galway

Investigators

  • Principal Investigator: Stewart R Walsh, FRCS, University College Hospital Galway

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2023

Primary Completion (Anticipated)

December 31, 2023

Study Completion (Anticipated)

June 30, 2024

Study Registration Dates

First Submitted

March 26, 2023

First Submitted That Met QC Criteria

March 26, 2023

First Posted (Actual)

April 7, 2023

Study Record Updates

Last Update Posted (Actual)

April 7, 2023

Last Update Submitted That Met QC Criteria

March 26, 2023

Last Verified

March 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 122/12

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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