Strategies to reduce post op pain in amputation. Candidates for limb amputation Risk of developing post-operative pain and phantom limb pain. Willing and able to participate in post-operative rehabilitation and physical therapy. Informed consent for the procedure and understand the potential risks and benefits. Adequate muscle function to allow for TMR surgery to be performed. Suitable for TMR surgery as per a surgeon's assessment.

1. Innovating limb
amputations in
Singapore
Targeted muscle reinnervation

2. Background
Riandini, Tet al 2022.
6 656 diabetic lower limb
minor amputations
4 724 diabetic major lower
limb amputations
571 non-diabetes
associated toe/ray
amputations
582 non-diabetes
associated major
amputation

3. Challenges
Pain
Sensory feedback
Precise control of myoelectric
prosthesis

4. Pain
phantom limb pain (PLP) ,neuropathic pain (NP), post amputation pain (PAP) and residual limb pain (RLP)
•PLP reported as 25% (Sin et al., 2013)
• 61% post op pain and 53% PLP with RLP at
32% (Schwinger et al., 2021)

5. Targeted Muscle reinnervation in limb amputation
•improving control and function of prosthesis (Kuiken
et al., 2017)
•potential to reduce phantom limb
•neuropathic pain by providing more normal
sensations (Peters et al., 2020).

6. Mechanism
• identifying the
nerves that
controlled the limb
• rerouting them to
new locations in
residual limb
• central sensitization
and maladaptive
neuronal
remodelling

7. BKA TMR

8. Tibial Nerve Nerve to soleus
Post Tibial Artery

9. Deep Peroneal
Br to tibialis anterior

10. Evidence
TMR at amputation to prevent post amputation pain
• primary intervention (Chappell et al., 2020; Dumanian et al., 2019;
O’Brien et al., 2021; Valerio et al., 2019).
• performed at time of amputation -prophylactic intervention
(McNamara and Iorio, 2020)
• reduce pathologic PLP and symptomatic neuroma-related RLP (Valerio
et al., 2019)

13. Clinical Pathway for Targeted Muscle Reinnervation (TMR)
an Intervention for Reducing Post-Operative Limb Pain in Limb Amputations
Clinically Indicated
Limb amputation
Fulfils inclusion
criteria
Recruited into
pathway
Primary surgeon
schedules surgery
Nerve surgeon
assists with nerve
identification and
transfer
Followed up
regularly (0w,
6w,3m,6m,12m)

14. Inclusion criteria
1. Candidates for limb amputation
2. Risk of developing post-operative pain and phantom limb pain.
3. Willing and able to participate in post-operative rehabilitation and physical therapy.
4. Informed consent for the procedure and understand the potential risks and benefits.
5. Adequate muscle function to allow for TMR surgery to be performed.
6. Suitable for TMR surgery as per a surgeon's assessment.

15. Exclusion criteria
1. Unable or unwilling to participate in post-operative rehabilitation and physical therapy.
2. No informed consent for the procedure or do not understand the potential risks and benefits.
3. Insufficient muscle function to allow for TMR surgery to be performed.
4. Contraindication for TMR surgery as per nerve surgeon's assessment.
5. History of severe mental illness, which may affect their ability to comply with the rehabilitation process.
6. Presence of active infection at the amputation site
7. History of poor wound healing, which may increase the risk of complications during and after the surgery.

16. Outcome measures Visual analogue scale (VAS)
DN4 for neuropathic pain
Phantom limb pain Phantom
Limb Pain Scale (PLPS)
Quality of life: EQ5D
Medical Research Council
(MRC) scale.
Patient satisfaction
questionnaire

17. Next steps
• Consensus
• Team members
• DSRB application
• Commencement date