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?
A: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.
What offloading modalities have you found to be successful in facilitating the healing of difficult post-op amputation wounds?
A:For Dr. Suzuki, the answer depends on the amputation level. If the patient has a simple toe amputation, he says a surgical shoe is sufficient. For a TMA, he often performs a tendo-Achilles lengthening at the same time since the patient will need to be in an immobilizing device such as a posterior splint or fiberglass cast. Dr. Suzuki follows this with a long-leg controlled ankle motion (CAM) walker for minimum non-weightbearing for four to six weeks until the incision and the Achilles tendon heal fully. Once the TMA heals completely, Dr. Suzuki prescribes an extra-depth shoe with a custom-molded insole and a forefoot filler. Some of his frugal patients have used a balled-up sock in the forefoot area so their foot does not slide back and forth in a regular shoe. Dr. Rice says there are a multitude of devices to help reduce foot load and facilitate healing. He prefers the following devices: OrthoWedge (Darco International); PegAssist postsurgical shoe with diabetic peg insole (Darco International); a diabetic Aircast CAM walker (DJO); old fashioned crutches; and Roll-A-Bout.
In your experience, what are the keys to fostering optimal healing for TMA procedures?
A:Dr. Bevilacqua supports having a comprehensive pre-op evaluation and multidisciplinary approach to ensure adequate blood flow as keys for healing a TMA. Likewise, blood flow is the most important factor for Dr. Suzuki. Dr. Bevilacqua also emphasizes elimination of all infected tissue at the time of closure and a meticulous surgical technique. He notes common pitfalls include excessive undermining, harsh handling of tissue, inadequate removal of infected bone or nonviable tissue, and inadequate hemostasis. Drs. Rice and Suzuki also cite the importance of good surgical techniques with Dr. Rice emphasizing meticulous hemostasis. During the TMA surgery, Dr. Suzuki makes sure to attain a proper parabola shape after ostectomy of all the metatarsals. He stresses the importance of cutting the fifth metatarsal shaft as proximal as possible as he has seen skin breakdown at the fifth metatarsal shaft to be the most common failure of TMA, closely followed by sub-first metatarsal ulcer. Drs. Bevilacqua and Rice also suggest employing tendo-Achilles lengthening along with TMA in patients with an equinus deformity along with other necessary soft tissue balancing procedures. Dr. Suzuki says tendo-Achilles lengthening is necessary as one may see wound breakdown in the distal stump, even after the incision is fully healed. In addition, Dr. Rice stresses non-weightbearing of the affected extremity as well as a detailed understanding of angiosomes and their blood supply to aid preoperative planning. Dr. Suzuki will also counsel patients on their nutrition, asking them about their appetite and blood glucose control at home. Ideally, he says patients should have high protein intake without fluctuating blood glucose levels if they have diabetes. He gives out handouts on proper nutrition as well as samples and coupons for Ensure, Glucerna and Juven (Abbott Laboratories). Dr. Suzuki notes that many of his elderly patients have poor appetites and/or dental problems that keep them from getting an adequate amount of protein. For postoperative patients, Dr. Suzuki says most nutritionists agree that they should have protein intake as high as 1.5 to 2 grams of protein per their body weight in kilograms every day. “In general, TMA is certainly the workhorse in our limb preservation practice,” says Dr. Suzuki. “When done properly, it creates a very stable and durable foot that can be walked on for many decades without problems. I personally know a double TMA amputee who plays golf almost every day.” Dr. Bevilacqua is a foot and ankle surgeon with North Jersey Orthopaedic Specialists in Teaneck, New Jersey. He is board certified in both foot surgery and reconstructive rearfoot and ankle surgery. He is a Fellow of the American College of Foot and Ankle Surgeons. Dr. Rice is an Assistant Clinical Professor in the Department of Orthopedics and Rehabilitation at Yale University School of Medicine. He is in private practice at Fairfield County Foot Surgeons in Norwalk, Conn. Dr. Rice is a Fellow of the American College of Foot and Ankle Surgeons. Dr. Suzuki is the Medical Director of the Tower Wound Care Center at the Cedars-Sinai Medical Towers. He is also on the medical staff of the Cedars-Sinai Medical Center in Los Angeles and is a Visiting Professor at the Tokyo Medical and Dental University in Tokyo. Dr. Suzuki can be reached via e-mail at Kazu.Suzuki@CSHS.org .
Wound Care Q&A