Healing Post-Op Amputation Wounds
Following amputation, patients can sometimes experience difficulty in healing their wounds. These expert panelists explore what leads to delayed amputation wound healing, successful offloading strategies and how to facilitate the healing of transmetatarsal amputations.
In your experience, what are the most difficult post-op amputation wounds to heal and why? What are the factors that contribute to delayed healing with these wounds?
Andrew Rice, DPM, FACFAS, has found the most difficult wounds to heal are open digital/partial metatarsal amputations of the fifth or first rays, particularly when no flap or advancement options are available and negative pressure wound therapies are the only options for attempting wound closure. As he says, this situation becomes even more challenging when the wound involves the weightbearing surface of the medial or lateral foot.
“Preserving function in both weightbearing and propulsion requires a close relationship with assistive devices, particularly with complete resection of the fifth ray, and distal and proximal first ray resection procedures,” notes Dr. Rice.
For Kazu Suzuki, DPM, CWS, it all depends on the patient’s overall status rather than the amputation level. As he points out, even a simple toe amputation at the metatarsophalangeal joint (MPJ) level can become a total disaster and turn gangrenous if one neglects to check the blood flow and control the infection adequately prior to performing the amputation. Dr. Suzuki emphasizes that good glucose control for patients with diabetes and smoking cessation are also important for adequate wound healing.
“I have witnessed so many surgical patients heal poorly after amputation procedures were done and they were discharged from the hospital because they have resumed smoking at home,” says Dr. Suzuki. “For that matter, it is important to educate them (smokers) on the importance of smoking cessation and how it could ruin the surgical outcome.”
In terms of blood flow assessment, he uses a laser Doppler device, SensiLase PAD-IQ (Vasamed), to measure skin perfusion pressure (SPP) near the amputation site. Ideally, Dr. Suzuki says the SPP level should be higher than 40 mmHg. If not, the patient needs a referral to a vascular specialist to increase the blood flow to the foot with angioplasty and/or surgical bypass procedures. He stresses the importance of this step in performing adequate vascular assessment for the sake of a better outcome as well as from a medicolegal perspective.
Surrounding soft tissue infection and osteomyelitis of a lesser MPJ often result in amputation of the digit and partial metatarsal resection, notes Nicholas Bevilacqua, DPM, FACFAS. He says this often results in a difficult to heal cleft wound.
After appropriate debridement, Dr. Bevilacqua says one manually compresses the forefoot (forefoot narrowing) and applies an external fixator to hold the position. He explains this technique allows for immediate closure and reduces tension at the incision site, facilitating primary closure of such difficult-to-heal cleft wounds.
Dr. Suzuki prefers transmetatarsal amputations (TMAs) in comparison to most partial ray amputation procedures. When surgeons perform TMAs properly, Dr. Suzuki says these procedures create an inherently stable and durable foot for ambulation while removing necrotic and infected tissues from the toes and forefoot. However, he tries to avoid performing more proximal foot amputations, such as a Chopart or Syme’s amputation. Dr. Suzuki notes more proximal amputations are fairly unstable in terms of biomechanics, are hard to “shoe and brace,” and hard for patients to walk on due to their instability.
Dr. Suzuki always performs tendo-Achilles lengthening along with all Chopart amputations as well as most TMAs, saying the calf muscle tends to overpower and pull on the stump. Without a tendo-Achilles lengthening, he warns patients could end up with a dislocated foot stump, especially in Chopart amputations.