Chopart amputation

Understanding Chopart Amputation

Chopart amputation is a surgical procedure involving disarticulation at the talonavicular and calcaneocuboid joints. This technique offers significant advantages over below-knee amputation, including better walking ability thanks to preserved limb length. Patients can also walk short distances without a prosthesis because direct weight-bearing on the residual limb is possible.

Surgical Steps for Chopart Amputation

To prevent contamination, begin with an incision on the back and inner side of the foot, then transect the Achilles tendon. Remove a 2 cm section of the tendon while preserving the tendon sheath. Handle soft tissues gently.
Preoperatively, mark the incision site on the skin, creating a “fish-mouth” shape on the sole. Start the incision at the inner and outer transverse tarsal joints. Pull the flaps upward and downward to ensure adequate skin coverage. Continue the incision through the skin and subcutaneous tissue.
Carefully locate superficial sensory nerves, pull them toward the toes, then cut and allow them to retract.
Identify the anterior tibial tendon and the extensor hallucis longus tendon. Cut them at a distance from their attachment points and prepare them for transfer.
Identify the transverse tarsal joints (calcaneocuboid and talonavicular) and separate them by releasing the ligaments above and below.
Transfer the anterior tibial tendon to the lateral side of the talar neck. This can be done through a bone tunnel secured with a biotenodesis screw, or by creating a groove in the talus and using a suture anchor or staple. Some experts suggest a single tendon transfer may not be enough to balance the foot. In addition to transferring the anterior tibial tendon to the talar neck, you can also transfer the peroneus brevis or extensor hallucis longus to the anterior calcaneal process. The anterior tibial and extensor hallucis longus tendons can be tenodesed and transferred to the talar neck, while the extensor digitorum longus tendon can be transferred to the front of the calcaneus.
Close the wound by aligning the connective tissue layers on the sole and top of the foot, then suture the skin without tension. Insert a drain if necessary after achieving hemostasis and thoroughly irrigating the wound.
Finally, apply a well-padded rigid dressing that maintains dorsiflexion.

Postoperative Care

The rigid dorsiflexion dressing is changed at intervals to check the wound. Sutures are left in place for 4 to 6 weeks to allow adequate healing.
To prevent equinus contracture of the hindfoot, the splint must be worn for 6 to 8 weeks.
For mobility, the patient requires an ankle-foot orthosis in a shoe with a rocker sole (e.g., a walking shoe).

Modified Chopart Amputation

A modified Chopart amputation was developed to overcome complications of the traditional procedure, such as plantarflexion and skin damage over the anterior talus and calcaneus. The modifications include:

Contouring of the talus and calcaneus.
Transfer of the anterior and posterior tibialis tendons, as well as the extensor communis and hallucis tendons, to the talar neck and sustentaculum tali.
Advancement of the plantar flap.
Achilles tendon lengthening.

Outcomes and Considerations

A systematic review study concludes that the need for re-amputation due to wound healing issues appears to be common, especially after conventional Chopart amputation. When considering a Chopart amputation, the modified technique shows a trend toward better outcomes in terms of wound healing and re-amputation rates compared to the traditional approach. Although the total number of patients studied is small, the Lisfranc amputation seems to favor both forms of Chopart amputation. With Lisfranc and both Chopart procedures, patients gain a functional stump with the remaining ability to walk short distances without a prosthesis.

References and Further Reading

van der Wal GE, Dijkstra PU, Geertzen JHB. Lisfranc and Chopart amputation: A systematic review. Medicine (Baltimore). 2023 Mar 10;102(10):e33188. doi: 10.1097/MD.0000000000033188. PMID: 36897730; PMCID: PMC9997832.
Letts M, Pyper A. The modified Chopart amputation. Clin Orthop Relat Res. 1990 Jul;(256):44-9. PMID: 2364621.
Campbell’s Operative Orthopaedics, 12th Edition.