Treatment
Offloading surgery: Achilles lengthening and tendon release for ulcers
Operations on the calf, Achilles or toe tendons (and sometimes a metatarsal bone) that take pressure off an ulcer so it heals and is less likely to come back.
Medically reviewed by Dr. Efe Ozturk · Last reviewed
Why a healed ulcer can open again
Lost feeling and high pressure on the sole both play a part in diabetic foot ulcers.[2] To heal an ulcer under the forefoot or midfoot, the first choice is a knee-high device that can’t be taken off.[1] We fit total contact casts and other locked-on knee-high devices and show you how to get around safely; see total contact casting.
A device protects the foot only while it is on, though, and ulcers that heal in a cast often come back.[2] Offloading surgery changes the foot itself, so the relief no longer depends only on a device being worn.[1] You will still wear an offloading device until the ulcer heals, and prescribed footwear afterward.[1,6]
For the ulcers that need it, Dr. Ozturk performs these operations himself: Achilles lengthening, gastrocnemius recession, toe tendon release and metatarsal head resection. As a Foot and Ankle Surgeon who is also board certified in wound care (FAPWH), he follows the wound from the first visit through healing. See also limb salvage surgery, diabetic foot ulcers and ulcers from foot deformity.
Who it helps
- An ulcer under the ball of the foot, with a tight calf. Diabetes can stiffen the Achilles tendon,[7] and this tightness (equinus) is about three times as common in people with diabetes.[2] A tight ankle often makes you lift the heel early, which loads the ball of the foot.[7] Guideline experts favor Achilles lengthening for a metatarsal head ulcer with this tightness, or one that moved to another metatarsal head after earlier bone surgery there.[1]
- An ulcer on the tip or underside of a bent toe. When the second to fifth toe still straightens by hand, releasing its flexor tendon is the recommended treatment.[1] It can also be considered before an ulcer forms, when a callus or blister on the tip of that toe keeps coming back despite non-surgical care such as callus treatment and silicone toe devices.[6] The big toe is excluded: the guideline panel judged its ulcers more likely to come from other deformities or a stiff joint.[1]
- A stubborn ulcer under a metatarsal head, or infected bone beneath it. The metatarsal heads are the bone ends at the ball of the foot. If non-surgical offloading hasn’t healed an ulcer under one, removing that bone end is an option.[1] Removing it, or part of the joint, should also be considered when a probe reaches bone or joint, or an MRI shows infection there.[1] See bone infection in the foot, surgery to remove infected bone and removing bony prominences under ulcers.
Surgical offloading isn’t done when the foot’s blood supply is severely reduced, so circulation comes first.[1] We check it with noninvasive circulation testing at our practice; if it is too low to heal, we work with a vascular specialist to restore it first. We also measure how far your ankle bends with the knee straight and bent, to tell a tight muscle or tendon from bone blocking the joint,[7] and take X-rays at the practice.
How the operations work
Achilles tendon lengthening
Swipe sideways to see the whole drawing.
Lengthening the Achilles tendon lets the ankle bend upward further. In the main trial it was done through small skin cuts (percutaneously), with a total contact cast.[3] In a gait study of 10 people with diabetes and a past forefoot ulcer, ankle bend improved from 0° to 9° and peak forefoot pressure fell by about a quarter eight weeks after surgery.[8]
Gastrocnemius recession
A gastrocnemius recession releases the tight gastrocnemius, the main calf muscle that points the foot down.[9] Like Achilles lengthening, it increases ankle motion.[2] A review found some support for it in forefoot and midfoot ulcers, though the evidence is still limited.[9] Our Center for Lower Extremity Surgery explains gastrocnemius recession (external site).
Toe tendon release (flexor tenotomy)
The tendon that curls a flexible claw toe or hammertoe down is divided, which can be done with a needle.[1,10] The release may lower pressure at the ulcer site considerably, and it is a relatively simple outpatient procedure.[1] For a rigid toe, the Center explains hammertoe surgery (external site).
What the results show
- Achilles lengthening. In the randomized trial, ulcers came back within seven months in 15% after lengthening plus a cast, versus 59% after the cast alone.[3]
- Achilles or calf procedures, pooled. A meta-analysis of the two randomized trials found healing similar to casting alone, but less than half the risk of the ulcer coming back.[2]
- A larger surgical series. In people with diabetes whose forefoot or midfoot ulcers were closed surgically, recurrent ulcers needing another operation fell from 25% to 2% once Achilles lengthening was added. This compared two time periods, not randomized groups, and the authors warn against lengthening too much.[11]
- Toe tendon release. In a randomized trial, all eight toe ulcers treated with a release plus standard care healed, against three of eight with standard care alone. Among people with warning signs, one of 39 developed an ulcer after a release, against seven of 40 without one; no serious adverse events were recorded.[10] Across six studies, recurrence was 6%, and none of the 57 toes released before an ulcer formed went on to ulcerate.[4]
Recovery
After Achilles lengthening, the foot stays in a cast until the ulcer heals: 58 days on average in the trial. Push-off strength and barefoot forefoot pressure dropped after surgery and were back to baseline by seven months, while the gain in ankle motion lasted.[3] Toe releases in the guideline’s evidence were paired with a removable ankle-high device.[1] We keep seeing you while the wound closes. Surgery doesn’t restore feeling, so prescribed pressure-relieving footwear afterward helps keep the ulcer from returning.[6] We fit therapeutic shoes and custom inserts; see protective footwear, keeping your foot in remission and recovery after limb salvage surgery.
Risks and limits
- Heel ulcers. Achilles lengthening likely increases new heel ulcers.[5] In the two randomized trials, seven of the people who had Achilles lengthening or calf recession (15%) developed one.[2] Over-lengthening can cause a heel-first gait (calcaneal gait), chronic heel ulcers or a torn tendon.[2]
- Pressure moving elsewhere. Toe releases may cause new transfer lesions.[5] Removing a metatarsal head may shift pressure to a neighboring bone, causing a new pressure spot, and problems are expected to be more likely at the big-toe joint than at the others.[1]
- Falls and infection. Achilles lengthening may increase falls and infections, though this evidence is of low certainty.[1]
- The evidence. Certainty of evidence for all offloading treatments is low to moderate.[5]
Questions to ask
- Is my ulcer caused by a tight calf, a bent toe, or a bone underneath?
- Has non-surgical offloading had a fair trial, and is my circulation good enough to heal?
- What is my risk of a heel ulcer or a new pressure spot?
- How will my foot be protected afterward, and which shoes will I need?
If you’ve been told you need an amputation, a limb salvage second opinion can help you weigh your choices.
When to seek care
See us within a day or two for any foot wound that isn’t healing, especially if you have diabetes.
References
- 1.Bus SA, Armstrong DG, Crews RT, Gooday C, Jarl G, Kirketerp-Moller K, et al. Guidelines on offloading foot ulcers in persons with diabetes (IWGDF 2023 update). Diabetes Metab Res Rev. 2024;40(3):e3647. PubMed 37226568 (external site)
- 2.Dallimore SM, Kaminski MR. Tendon lengthening and fascia release for healing and preventing diabetic foot ulcers: a systematic review and meta-analysis. J Foot Ankle Res. 2015;8:33. PubMed 26300980 (external site)
- 3.Mueller MJ, Sinacore DR, Hastings MK, et al. Effect of Achilles tendon lengthening on neuropathic plantar ulcers. A randomized clinical trial. J Bone Joint Surg Am. 2003;85(8):1436-45. PubMed 12925622 (external site)
- 4.Bonanno DR, Gillies EJ. Flexor Tenotomy Improves Healing and Prevention of Diabetes-Related Toe Ulcers: A Systematic Review. J Foot Ankle Surg. 2017;56(3):600-604. PubMed 28476394 (external site)
- 5.Lazzarini PA, Armstrong DG, Crews RT, et al. Effectiveness of offloading interventions for people with diabetes-related foot ulcers: A systematic review and meta-analysis. Diabetes Metab Res Rev. 2024;40(3):e3650. PubMed 37292021 (external site)
- 6.Bus SA, Sacco ICN, Monteiro-Soares M, Raspovic A, Paton J, Rasmussen A, et al. Guidelines on the prevention of foot ulcers in persons with diabetes (IWGDF 2023 update). Diabetes Metab Res Rev. 2024;40(3):e3651. PubMed 37302121 (external site)
- 7.American College of Foot and Ankle Surgeons. Equinus. FootHealthFacts. foothealthfacts.org (external site)
- 8.Armstrong DG, Stacpoole-Shea S, Nguyen H, et al. Lengthening of the Achilles tendon in diabetic patients who are at high risk for ulceration of the foot. J Bone Joint Surg Am. 1999;81(4):535-8. PubMed 10225799 (external site)
- 9.Cychosz CC, Phisitkul P, Belatti DA, et al. Gastrocnemius recession for foot and ankle conditions in adults: Evidence-based recommendations. Foot Ankle Surg. 2015;21(2):77-85. PubMed 25937405 (external site)
- 10.Askø Andersen J, Rasmussen A, Engberg S, et al. Flexor Tendon Tenotomy Treatment of the Diabetic Foot: A Multicenter Randomized Controlled Trial. Diabetes Care. 2022;45(11):2492-2500. PubMed 36151947 (external site)
- 11.Colen LB, Kim CJ, Grant WP, et al. Achilles tendon lengthening: friend or foe in the diabetic foot? Plast Reconstr Surg. 2013;131(1):37e-43e. PubMed 23271552 (external site)
This page is general health information and isn’t a substitute for advice from a clinician who knows your history. Read our medical disclaimer and how we review content.
Questions patients ask
Articles from our blog on healing a wound, protecting the foot and the surgery that saves it, with the sources listed.
Limb salvage surgery
Toe-Tip Ulcers and Flexor Tenotomy: A Small Procedure, a Big Benefit
An ulcer on the tip of a bent toe is usually a pressure problem with a small fix. How a flexor tenotomy works, who it suits, what the trials found and the trade-offs.
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Achilles Lengthening for Forefoot Ulcers That Keep Coming Back
A tight calf can keep an ulcer under the ball of the foot from healing or staying healed. Who the operation suits, what the trials found and the trade-offs.
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Ulcers & offloading
Life in a Total Contact Cast: What the First Weeks Are Like
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Related topics
Condition
Ulcers from foot deformity
Ulcers that form over bent toes, bunions and prominent bones on a foot with reduced feeling, and how offloading and surgery heal them.
Condition
Diabetic foot ulcers
Open sores on the feet of people with diabetes, and the step-by-step care, including surgery when it’s needed, that aims to heal them and keep them closed.
Treatment
Exostectomy
Removing the bump of bone under an ulcer that won’t heal, from a collapsed Charcot arch to the ball of the foot: who it suits, results and recovery.
Treatment
Total contact casting
A knee-high cast or locked walker you can’t take off, which spreads pressure away from a foot ulcer so it can heal.
Condition
After an ulcer heals
How to keep a healed diabetic foot ulcer from coming back, from protective shoes and daily checks to surgery that reduces the pressure behind it.