硬性ハンマートゥに対する経皮屈筋腱切開術と足底関節包剥離術の併用：屍体解剖学的研究

Rigid hammertoe deformities in diabetic patients present a therapeutic challenge: percutaneous tenotomy often fails to address capsular contractures, whereas arthrodesis carries an elevated risk of complications. We hypothesized that combining tenotomy with plantar capsule release would provide effective correction while preserving neurovascular structures. This study evaluates the feasibility correction magnitude and vascular safety of this technique through a cadaveric model.

We perfused 10 clinical-grade lower-limb cadaveric specimens, possessing 14 rigid hammertoes (N = 14), with an India ink-latex mixture to highlight vascular structures. Specimens with significant pathology or prior forefoot surgeries were excluded. The angle of the hammertoe deformity was measured using a goniometer preoperatively, after percutaneous flexor tenotomy, and again after releasing the plantar capsule. Standard dissection was then conducted to assess the common plantar digital arteries.

Mean preoperative contracture of 56.5 (range 15-86) degrees improved to 26.8 (range 0-60) degrees (47.4%) after tenotomy of the flexor digitorum brevis and longus tendons, with 1 toe releasing fully. In cases where full release was not achieved following tenotomy, plantar capsule release was performed. Full release was obtained in 92% of the cases undergoing plantar capsule release. Importantly, no iatrogenic injury occurred to the plantar medial and lateral digital arteries during the procedure.

In cadaveric specimens, partial release of the rigid hammertoe deformity was seen following flexor tenotomy in all but 1 toe. The addition of a proximal interphalangeal joint plantar capsule release was effective at obtaining full release, without evidence of vascular injury. As such, combining tenotomy with plantar capsule release showed effective correction in this cadaveric model and may represent a less invasive option for correcting rigid hammertoes in an outpatient setting.

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This technique may offer diabetic patients a lower-risk alternative to arthrodesis, potentially reducing ulcer-related amputations through earlier intervention in outpatient settings.