Trans Metatarsal Amputation (TMA)
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A colleague asked are there common biomechanical traits and needs for patients who have undergone a trans metatarsal amputation?
Yes. Patients who undergo a trans metatarsal amputation (TMA) commonly develop a recognizable set of biomechanical deficiencies and long-term functional needs that often require some form of prosthetic intervention.
Key biomechanical traits and needs include:
- Loss of forefoot leverage and propulsion during gait
- Reduced push-off power and shortened stride length
- Increased instability during stance and late gait phases
- Higher plantar pressures at the distal stump
- Risk of recurrent ulceration and skin breakdown
- Progressive deformities such as:
- Equinus
- Varus
- Cavus tendencies
- Muscle imbalance due to loss or compromise of:
- Digital extensors and flexors/pronators
- Peroneus brevis function, especially with infection
- Achilles tendon integrity (especially in diabetic patients)
- Altered gait mechanics leading to compensatory stress at the ankle, knee, hip, and contralateral limb
The patient’s needs depend heavily on:
- Whether the TMA is partial or complete
- Time elapsed since surgery
- Presence of infection, debridement, tendon loss, or neuropathy
- Current gait deficits and functional limitations
- Progression of deformity over time
Common orthotic/prosthetic goals include:
- Redistributing pressure away from the stump
- Preventing ulceration and further amputation
- Improving stability and balance
- Restoring rollover and propulsion
- Reducing energy expenditure during gait to reduce cardiopulmonary stress
- Improving mobility activities of daily living (mADL)
Typical devices may include:
- Custom toe fillers (L5000)
- Toe fillers with rigid rocker reinforcement (L2755)
- Carbon or laminated shank additions (L2755) to the toe filler.
- Rocker sole footwear or shank rocker sole added to footwear
- More proximal prosthetics for more advanced instability or deformity
A major clinical and reimbursement point is that documentation must go beyond physical findings and diagnosis alone. Providers should specifically document:
- The biomechanical deficit present
- How the prescribed device corrects or compensates for it
- Expected improvement in gait and mADL at the time of ordering.
- Functional outcomes after dispensing
This functional justification is especially important for Medicare coverage of lower-limb prosthetic and AFO devices.
Overall, TMA patients typically require lifelong biomechanical management, with orthotic/prosthetic needs evolving over time as the residual limb or contralateral limb changes.
Because toe fillers are incorporated into the lower limb prosthetic LCD and not therapeutic shoe LCD, there is no five year look back and no cumbersome paperwork associated with the Therapeutic Shoe Program. Replacements are based on medical necessity. Reimbursement for L5000 has a range from over $600-$900.
Whether the patient has a complete TMA or partial TMA, KevinRoot Medical is available to help connect you with experienced professionals who can assist with all of your enrollment needs, while also supporting practices with premium Root orthotics, custom solutions, and advanced lower-extremity biomechanical technologies designed for today’s modern podiatric practice.
Some patients may need more than the toe filler with a rigid shank. Some other options will be discussed in our next issue!
Disclaimer: CPT codes are copyrighted by the AMA, all rights reserved. HCPCS codes are the property of CMS
