Ulcers at the tip or apex of a toe are among the most difficult diabetic foot wounds to offload. Casts, boots, and insoles redistribute pressure across the forefoot and midfoot; none reliably unloads the end of a buckled toe pressing into a shoe. Because these lesions sit directly over bone with almost no soft-tissue padding, they progress quickly to infection and osteomyelitis, and they account for a disproportionate share of digital amputations. Over the past decade, a minimally invasive procedure — percutaneous flexor tendon tenotomy — has moved from a small case-series curiosity to a guideline-endorsed intervention.
The mechanical problem: flexible claw and hammertoe deformity
Motor neuropathy in diabetes weakens the intrinsic muscles of the foot, allowing the long flexor tendons to overpower them. The toe buckles at the interphalangeal joints and the tip is driven downward into the ground or the shoe insole. When the deformity is still flexible — passively correctable — the driver of the ulcer is tendon pull, not fixed bony architecture.
Percutaneous flexor tenotomy addresses exactly that. Through a needle puncture or a small blade entry at the base of the toe, the flexor digitorum longus tendon (and often brevis) is divided, releasing the deforming force. No implant is used, and the procedure is routinely performed in an outpatient clinic under local anaesthesia.
Measured pressure reduction
The biomechanical effect has now been quantified. In a randomized substudy of the Copenhagen tenotomy trial, Askø Andersen and colleagues measured barefoot peak plantar pressure before and three months after the procedure. Peak pressure in the toe regions fell from a median 205.6 kPa to 61.3 kPa in the tenotomy group, while the control group showed essentially no change (BMJ Open Diabetes Research & Care, 2024). An earlier observational series from Amsterdam UMC reported a mean reduction of 279 kPa alongside significant reductions in metatarsophalangeal, proximal interphalangeal, and distal interphalangeal joint angles (Mens et al., Diabetic Medicine, 2021).
What the clinical evidence shows
The strongest data come from a multicentre randomized controlled trial conducted at Steno Diabetes Center Copenhagen and North Zealand Hospital. Ninety-five participants with diabetes and hammertoe deformity were randomized to needle tenotomy plus standard non-surgical care, or standard care alone, and stratified by whether they presented with an active ulcer or an impending (pre-ulcerative) lesion. Among those with active ulcers, healing occurred in 100% of tenotomy patients versus 37.5% of controls. Among those with pre-ulcerative lesions, progression to an open ulcer occurred in 1 tenotomy patient versus 7 controls, and ulcer-free days were significantly higher after tenotomy. No serious adverse events were recorded (Askø Andersen et al., Diabetes Care, 2022).
Observational evidence points the same direction. A 2023 systematic review of 11 studies reported healing rates of 92–100% with a mean healing time of two to four weeks, few complications, and low recurrence (Calvo-Wright et al., Journal of Clinical Medicine). An earlier systematic review by Scott and colleagues found comparable healing figures across five case series but graded the evidence as level 4, cautioning that uncontrolled designs limited confidence (Journal of Foot and Ankle Research, 2016). A prospective outpatient case series of 76 procedures reported mean healing at 10.2 days with a per-episode infection rate of 2.8% and uniformly high patient satisfaction (Smith and Miller, Foot & Ankle Specialist, 2019).
Limitations, transfer lesions, and long-term outcomes
Two caveats recur across the literature. The first is transfer lesions: releasing one toe shifts load to its neighbours, and reported rates range from roughly 13% to 15%. Several authors suggest that tenotomy of all lesser toes in the same sitting largely eliminates this risk. The second is patient selection. Tenotomy assumes a flexible deformity driven by flexor pull; in a cross-sectional analysis of digital deformities, roughly a third of feet showed extensor substitution patterns in which tenotomy may worsen rather than correct the toe posture, arguing for dynamic assessment before surgery (Sanz-Corbalán et al., Journal of Foot and Ankle Surgery, 2019).
Long-term follow-up also tempers enthusiasm. Fifteen patients from an original 2006–2009 tenotomy cohort were re-examined at a mean of 12.5 years. Deformity had recurred in 22.7% of treated toes, 93% of patients had sustained at least one new ulcer somewhere on the foot, 53% had undergone an amputation, and 55% of the original cohort had died during follow-up (Andersen et al., Clinical Medicine Insights: Endocrinology and Diabetes, 2025). Tenotomy resolves one mechanical problem; it does not alter the underlying neuropathy, vascular disease, or systemic risk.
Where guidelines stand
The 2023 IWGDF offloading guideline recommends digital flexor tendon tenotomy for healing a neuropathic plantar or apex lesser-digit ulcer secondary to flexible toe deformity. The companion prevention guideline suggests considering tenotomy in people with non-rigid hammertoe and a pre-ulcerative lesion, and the underlying systematic review classified the supporting evidence as low certainty — one randomized trial plus seven non-controlled studies (Bus et al., 2023; van Netten et al., 2023).
Summary
Percutaneous flexor tenotomy is a low-burden procedure with a clear mechanical rationale, consistent evidence of rapid healing for apex toe ulcers, and randomized support for both healing and prevention in flexible hammertoe deformity. Its limits are equally clear: it is inappropriate for rigid or extensor-driven deformities, it carries a modest risk of transfer lesions unless adjacent toes are addressed, and it does not change the long-term trajectory of a high-risk foot. It belongs within comprehensive diabetic foot care, not as a substitute for it.
References
- 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. doi:10.2337/dc22-0085
- Askø Andersen J, Rasmussen A, Engberg S, et al. Effect of flexor tendon tenotomy of the diabetic hammertoe on plantar pressure: a randomized controlled trial. BMJ Open Diabetes Research & Care. 2024;12(6):e004398. doi:10.1136/bmjdrc-2024-004398
- Bus SA, Armstrong DG, Crews RT, et al. Guidelines on offloading foot ulcers in persons with diabetes (IWGDF 2023 update). Diabetes/Metabolism Research and Reviews. 2024;40(3):e3647. doi:10.1002/dmrr.3647
- van Netten JJ, Raspovic A, Lavery LA, et al. Prevention of foot ulcers in persons with diabetes at risk of ulceration: A systematic review and meta-analysis. Diabetes/Metabolism Research and Reviews. 2024;40(3):e3652. doi:10.1002/dmrr.3652
- Calvo-Wright MM, López-Moral M, García-Álvarez Y, et al. Effectiveness of Percutaneous Flexor Tenotomies for the Prevention and Management of Toe-Related Diabetic Foot Ulcers: A Systematic Review. Journal of Clinical Medicine. 2023;12(8):2835. doi:10.3390/jcm12082835
- Mens MA, van Netten JJ, Busch-Westbroek TE, et al. Biomechanical and musculoskeletal changes after flexor tenotomy to reduce the risk of diabetic neuropathic toe ulcer recurrence. Diabetic Medicine. 2022;39(4):e14761. doi:10.1111/dme.14761
- Scott JE, Hendry GJ, Locke J. Effectiveness of percutaneous flexor tenotomies for the management and prevention of recurrence of diabetic toe ulcers: a systematic review. Journal of Foot and Ankle Research. 2016;9:25. doi:10.1186/s13047-016-0159-0
- Smith SE, Miller J. The Safety and Effectiveness of the Percutaneous Flexor Tenotomy in Healing Neuropathic Apical Toe Ulcers in the Outpatient Setting. Foot & Ankle Specialist. 2020;13(2):123–131. doi:10.1177/1938640019843314
- Sanz-Corbalán I, Lázaro-Martínez JL, García-Álvarez Y, et al. Digital Deformity Assessment Prior to Percutaneous Flexor Tenotomy for Managing Diabetic Foot Ulcers on the Toes. Journal of Foot and Ankle Surgery. 2019;58(3):453–457. doi:10.1053/j.jfas.2018.09.015
- Andersen JA, Rasmussen A, Frimodt-Møller M, et al. Long Term Outcomes After Flexor Tendon Tenotomy of the Diabetic Foot. Clinical Medicine Insights: Endocrinology and Diabetes. 2025;18:11795514251314787. doi:10.1177/11795514251314787
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