Repair of Thumb Defect by Using the Toe Nail Flap

Study Overview
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Brief Summary
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The thumb accounts for 50% of the total hand function. This study reports the functional outcomes and complications of people with traumatic thumb amputations who underwent toe-to-thumb reconstruction.From 2013-01 to 2018-01, 29 patients with second-degree thumb defect underwent thumb reconstruction with distal phalangeal braided toenail flap. The footscan foot pressure gait analysis system was used to measure the index changes of the same foot before and after one, three and six months. The contact area, peak pressure, impulse value, contact time of each gait phase, centre of gravity coordinate and foot balance were analysed statistically. Twenty-nine cases of thumb reconstruction recovered well. After following up for 6-15 months, the appearance of the reconstructed thumb was close to normal, and the sensation was restored to S3+. The two-point discrimination was 6-8 mm, and the function of the thumb was good. The function of the donor foot was well restored, and no skin ulceration, pain and claudication were noted during walking. Compared with that before operation, the biomechanical indices of the donor foot were basically restored to normal six months after operation. Only the stress and impulse values of the third metatarsal head were significantly increased, forming a stress concentration area centred on the third metatarsal head.This study confirmed that the toe nail flap with distal phalangeal bone restored the second-degree thumb defect without destroying the main functional structure of the sole. The biomechanical indices of the donor foot were basically restored to normal six months after operation. Only the stress concentration area centred on the third metatarsal head, and the pain on the forefoot was induced after the operation. Discomfort, callus formation, metatarsal fasciitis, etc. can lead to fatigue fracture of the third metatarsal bone in severe cases, which requires further follow-up and observation.

Official Title
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Repair of Thumb Defect by Using the Toe Nail Flap: Biomechanical Analysis of Donor Foot ,a Retrospective Cohort Study

Conditions
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Thumb Injury

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with second-degree thumb defect； without any foot disease or deformity before injury； Written informed consent to undergo the surgical procedure； Exclusion Criteria: Concomitant phalanx fractures or other injuries needing immobilization； Loss of skin substance requiring grafts or flaps Uncompensated diabetes, neoplasia, haemocoagulative alterations, psychic disorders Smokers

Ages Eligible for Study
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Minimum Age: 17 Years
Maximum Age: 46 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The contact area | According to the anatomical region, the plantar was divided into eight stress regions.The increase or decrease of contact area reflects the stress distribution of sole after operation. | Six months | 
| Peak pressure | Its increase indicates that the pressure in the unit area increases when the sole touches the ground. | Six months | 
| Impulse value | Impulse value refers to the product of touchdown time and pressure in each stress area of the foot in each cycle. The increase of impulse is more suggestive of fatigue damage and subsequent foot deformities. | Six months | 
| Contact time of each gait phase | The increase or decrease it reflects the stress distribution of sole after operation. | Six months | 
| Foot balance | Foot balance refers to the difference of compressive stress between the inside and the outside of the foot at a certain time. | Six months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Amputation, thumb reconstruction, toe transfer, foot morbidity, biomechanics