Can a transmetatarsal (below the ball of the foot) amputation and a partial calcanectomy (partial removal of the calcaneus bone) be performed on the same foot?

Transmetatarsal Amputation with Partial Calcanectomy on the Same Foot

Yes, a transmetatarsal amputation and partial calcanectomy can be performed on the same foot when clinically indicated, though this combined approach should be reserved for specific clinical scenarios where both procedures are necessary for limb salvage.

Clinical Indications for Combined Procedure

Primary Indications

• Concurrent pathology in different foot regions:
  • Forefoot infection/gangrene requiring transmetatarsal amputation
  • Calcaneal osteomyelitis or heel ulceration requiring partial calcanectomy
• Limb salvage strategy to avoid more proximal amputation (e.g., below-knee amputation) 1
• Failed previous isolated procedures with persistent or recurrent infection

Biomechanical Considerations

• The procedures address different functional areas of the foot:
  • Transmetatarsal amputation: Removes forefoot at metatarsal level
  • Partial calcanectomy: Removes infected/necrotic portion of calcaneus while preserving hindfoot function

Evidence Supporting Combined Approach

Research shows that partial foot amputations, including both transmetatarsal amputations and calcanectomies, can be viable alternatives to transtibial (below-knee) amputations 2:

• Transmetatarsal amputations demonstrate:

  • Lower 5-year mortality rates (30%) compared to transtibial amputations (45%)
  • Better functional outcomes (ambulatory score 4.3 vs 2.8)
  • Lower reamputation rates

• Partial calcanectomy outcomes:

  • Approximately 85% of patients maintain or improve ambulatory status 3
  • Only about 10% require subsequent major lower extremity amputation
  • Can effectively address calcaneal osteomyelitis while preserving limb function

Surgical Planning Considerations

Pre-operative Assessment

1. Vascular status evaluation:

   • Palpation of pedal pulses
   • Ankle-brachial index (ABI) and toe-brachial index (TBI) measurements
   • Vascular imaging if signs of inadequate perfusion 4

2. Infection assessment:

   • Evaluate extent of infection in both forefoot and hindfoot
   • Determine if osteomyelitis is present in both locations
   • Consider MRI to delineate extent of bone involvement

3. Functional goals:

   • Assess potential for ambulation post-procedure
   • Consider pre-existing mobility status

Surgical Technique

• Staging options:

  1. Simultaneous procedure: Both transmetatarsal amputation and partial calcanectomy performed in one operation
  2. Staged approach: Address more urgent pathology first, followed by secondary procedure

• Technical considerations:

  • Ensure adequate soft tissue coverage for both surgical sites
  • Consider vertical contour calcanectomy technique for better soft tissue closure 5
  • Preserve as much viable bone and soft tissue as possible

Post-operative Management

Wound Care

• Assess for signs of infection including erythema, warmth, tenderness, pain, induration, and purulent secretions 4
• Evaluate wound size, depth, and undermining
• Consider non-removable knee-high device once infection is controlled 4

Rehabilitation

• Early mobilization with appropriate offloading devices
• Custom orthotic devices to accommodate both forefoot and hindfoot alterations
• Physical therapy focused on gait training with altered foot biomechanics

Outcomes and Prognosis

Expected Outcomes

• Limb preservation in cases that would otherwise require transtibial amputation
• Functional ambulation with appropriate orthotic support
• Potential complications:
  • Higher risk of delayed wound healing in diabetic patients 6
  • Possible need for additional procedures (11-24% of cases) 3, 6

Risk Factors for Poor Outcomes

• Diabetes increases risk of complications and need for further amputation 3
• Poor vascular status
• Extensive infection or osteomyelitis
• Inability to comply with offloading and rehabilitation protocols

Conclusion

While technically challenging, the combination of transmetatarsal amputation and partial calcanectomy on the same foot represents a viable limb salvage strategy in appropriately selected patients. This approach preserves more limb length and function compared to transtibial amputation, potentially offering better functional outcomes and quality of life 2. However, careful patient selection, meticulous surgical technique, and comprehensive post-operative care are essential for successful outcomes.