Clinical Evaluation of the Access Socket Flexible Socket for Transtibial Prosthesis (AS-TT)
Transtibial amputation significantly impacts patient autonomy and quality of life, primarily due to the limitations of conventional rigid sockets, which restrict comfort and joint range of motion. The Access Socket (AS) is an innovative prosthetic socket combining a rigid carbon-fiber structure in key load-bearing areas with flexible urethane-resin (ProtheFLEX®) zones in regions typically rigid in conventional sockets. This hybrid design aims to improve comfort and pressure distribution while preserving the mechanical properties required for ambulation.
The AS has already demonstrated benefits in transfemoral amputees and is now reimbursed in France for that population. A preliminary uncontrolled study in 12 transtibial amputees suggested significant improvements in perceived function, comfort, satisfaction, and mobility.
This multicenter, randomized, open-label, two-arm crossover study aims to compare the (AS) with the standard rigid socket (RS) in 25 adults with transtibial amputation. Participants will wear each socket for approximately 4 weeks (after a 1-2 week adaptation period) in a randomized order. The primary outcome is the Patient Specific Functional Scale (PSFS). Secondary outcomes include comfort (SCS), satisfaction (OPUS), psychosocial adjustment (TAPES-R), mobility (PLUS-M), prosthesis utility (PEQ-U), and the proportion of patients electing to keep the AS at study completion.
調査の概要
詳細な説明
Background. Lower-limb amputation affects more than 7,500 people annually in France, with approximately 50% at the transtibial level. The socket is the critical interface between the residual limb and the prosthesis, transmitting mechanical forces while needing to remain comfortable. Currently, only RS (carbon or resin) are listed on the French reimbursable products list (LPPR) for transtibial amputation. Documented limitations of rigid sockets include restricted knee flexion, walking discomfort in challenging environments, donning difficulties, and suboptimal pressure distribution that does not adapt to residual-limb volume changes.
Investigational device. The AS follows the same molding and shaping principles as the standard RS but differs in two manufacturing steps: (1) carbon fibers are placed only on lateral, postero-inferior, and inferior areas to provide structural rigidity; (2) stratification uses urethane resin (ProtheFLEX®, already used in medical-device manufacturing) instead of epoxy or acrylic resin, creating soft zones in regions typically rigid in conventional sockets.
Comparator. Both sockets are manufactured from the same plaster mold to ensure strictly identical internal geometry. Only the material structure (carbon/urethane distribution) differs; all other prosthetic components (intermediate piece, prosthetic foot) are identical.
Design rationale. A double-blind design is not feasible because participants can perceive differences in socket rigidity and prosthesis weight. The crossover design controls for between-subject variability and order effects.
Sample size. Based on the preliminary study (Patient Specific Functional Scale (PSFS) standard deviation 1.74), to detect a difference of 1.3 points (the PSFS MDC₉₀ for 3 items) with 80% power and α=0.05, 19 participants are required. 25 will be enrolled to account for dropouts and to provide a more representative sample for secondary endpoints.
Visits. Four study visits over approximately 14-21 weeks per participant: inclusion (V0), evaluation after first socket period (V1), evaluation after second socket period (V2), and an optional follow-up visit (V3) one month later if the participant elects to keep the AS.
研究の種類
入学 (推定)
段階
- 適用できない
連絡先と場所
研究連絡先
- 名前：Isabelle Loiret, MD
- 電話番号：+33383529950
- メール：isabelle.loiretpro@gmail.com
研究連絡先のバックアップ
- 名前：Jonathan Pierret, PhD
- メール：jonathan.pierret@ugecam.assurance-maladie.fr
研究場所
-
-
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Clamart、フランス、92140
- 募集
- Hôpital National d'Instruction des Armées (HNIA) Percy
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主任研究者：
- Marie Thomas-Pohl, MD
-
コンタクト：
- Marie Thomas-Pohl, MD
- 電話番号：+33 1.41.46.62.82
- メール：marie.thomas@intradef.gouv.fr
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Freyming-Merlebach、フランス、57804
- 募集
- Hôpital Filieris de Freyming-Merlebach
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コンタクト：
- Catherine Achour, MD
- 電話番号：+33 3 83 52 98 61
- メール：catherine.achour@filieris.fr
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主任研究者：
- Catherine Achour
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Grenoble、フランス、38434
- 募集
- CHU Grenoble Alpes - Hôpital Sud
-
コンタクト：
- Solène Maret, MD
- 電話番号：+33 4 76 76 60 25
- メール：smaret2@chu-grenoble.fr
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主任研究者：
- Solène MAret, MD
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副調査官：
- Phillipe Escobar, MD
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Nancy、フランス、54000
- 募集
- Institut Régional de Médecine Physique et de Réadaptation (IRR) - Filière Locomoteur
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主任研究者：
- Isabelle Loiret, MD
-
コンタクト：
- Jonathan Pierret, PhD
- メール：jonathan.pierret@ugecam.assurance-maladie.fr
-
コンタクト：
- Christelle REQUENA
- 電話番号：+33 3 83 52 98 61
- メール：christelle.requena@ugecam.assurance-maladie.fr
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Paris、フランス、75007
- 募集
- Insititution Nationale des Invalides
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コンタクト：
- Joseph Bascou, PhD
- 電話番号：+33 3 87 51 30 30
- メール：joseph.bascou@invalides.fr
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-
参加基準
適格基準
就学可能な年齢
- 大人
- 高齢者
健康ボランティアの受け入れ
説明
Inclusion Criteria:
- Unilateral or bilateral transtibial amputation
- Currently fitted with a definitive carbon rigid socket
- Any residual-limb shape
- Any etiology
- Able to understand simple instructions, read, write, and provide informed consent - or able to be accompanied by a trusted person in case of inability to read/write autonomously
- Provided free written informed consent
- Aged 18 years or older
- Affiliated to a social security system
Exclusion Criteria:
- Use of hydroalcoholic solution (HAS) for socket donning
- Currently fitted with a provisional socket
- Neurological pathology limiting capacity to participate in activities
- Orthopedic pathology limiting capacity to participate in activities
- Pregnant or breastfeeding women
- Minors
- Persons not under legal protection or unable to express consent
- Persons under guardianship or curatorship
- Persons under judicial protection
研究計画
研究はどのように設計されていますか？
デザインの詳細
- 主な目的：処理
- 割り当て：ランダム化
- 介入モデル：クロスオーバー割り当て
- マスキング：なし（オープンラベル）
武器と介入
参加者グループ / アーム |
介入・治療 |
|---|---|
|
アクティブコンパレータ：Group 1 (RS -> AS)
Participants wear their standard rigid socket (RS) for 4 weeks, complete evaluation, then switch to the Access Socket (AS) for 1-2 weeks of adaptation followed by 4 weeks of wear, with a second evaluation.
|
Hybrid prosthetic socket combining a rigid carbon-fiber structure in load-bearing areas (lateral, postero-inferior, inferior) with flexible urethane-resin (ProtheFLEX®) zones in regions typically rigid in conventional sockets.
Manufactured from the same plaster mold as the rigid socket to ensure identical internal geometry.
Conventional definitive carbon-fiber rigid socket, currently the only socket type reimbursed in France for transtibial amputation (LPPR-listed).
Standard of care comparator.
|
|
アクティブコンパレータ：Group 2 (AS -> RS)
Participants receive the Access Socket (AS) first, with 1-2 weeks of adaptation followed by 4 weeks of wear and evaluation.
They then switch to the standard rigid socket (RS) for 1-2 weeks of adaptation and 4 weeks of wear, with a second evaluation.
|
Hybrid prosthetic socket combining a rigid carbon-fiber structure in load-bearing areas (lateral, postero-inferior, inferior) with flexible urethane-resin (ProtheFLEX®) zones in regions typically rigid in conventional sockets.
Manufactured from the same plaster mold as the rigid socket to ensure identical internal geometry.
Conventional definitive carbon-fiber rigid socket, currently the only socket type reimbursed in France for transtibial amputation (LPPR-listed).
Standard of care comparator.
|
この研究は何を測定していますか？
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Patient Specific Functional Scale (PSFS) score
時間枠：One time at the end of each 4-week wear period (V1, V2 and V3)
|
Patient-centered self-report tool.
The patient identifies 3-5 specific activities they have difficulty performing, then rates their ability on a 0-10 scale (0 = unable to perform, 10 = able to perform at pre-injury level).
The final score is the mean of the ratings
|
One time at the end of each 4-week wear period (V1, V2 and V3)
|
二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Socket Comfort Scale (SCS) score
時間枠：One time at the end of each 4-week wear period (V1, V2 and V3)
|
0-10 numerical rating of socket comfort (0 = least comfortable imaginable, 10 = most comfortable imaginable)
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One time at the end of each 4-week wear period (V1, V2 and V3)
|
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Orthotics Prosthetics Users Survey (OPUS) score
時間枠：One time at the end of each 4-week wear period (V1, V2 and V3)
|
Self-report instrument evaluating functional outcomes and quality of life specifically for orthosis and prosthesis users.
Assesses lower-limb functional status, health-related quality of life, satisfaction with the device, and satisfaction with services.
The higher the score, the more favorable the result for the device
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One time at the end of each 4-week wear period (V1, V2 and V3)
|
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Trinity Amputation and Prosthesis Experience Scale - Revised (TAPES-R) score
時間枠：One time at the end of each 4-week wear period (V1, V2 and V3)
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33-item multidimensional questionnaire evaluating psychosocial adjustment to amputation and prosthesis use, including general adjustment, social adjustment, activity restriction, and prosthesis satisfaction.
The higher the global score, the more favorable the result for the device
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One time at the end of each 4-week wear period (V1, V2 and V3)
|
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Prosthesis Evaluation Questionnaire - Utility subscale (PEQ-U) score
時間枠：One time at the end of each 4-week wear period (V1, V2 and V3)
|
The score is calculated as the mean of the 8 items in the subscale.
Each item is rated on a Visual Analogue Scale (VAS) from 0 to 100.
The total score ranges from 0 to 100, where higher scores indicate a better outcome (greater satisfaction and prosthesis utility)
|
One time at the end of each 4-week wear period (V1, V2 and V3)
|
|
Proportion of participants electing to keep the Access Socket at study completion
時間枠：Through study completion, an average of 10 weeks
|
Percentage of participants who choose the AS over the RS at the end of the study, reported with 95% confidence interval.
Participants are not informed of this option until the end of the study to avoid judgment bias
|
Through study completion, an average of 10 weeks
|
協力者と研究者
協力者
捜査官
- 主任研究者：Isabelle Loiret, MD、Institut Régional de Médecine Physique et de Réadaptation (IRR), Nancy, France
研究記録日
主要日程の研究
研究開始 (実際)
一次修了 (推定)
研究の完了 (推定)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (実際)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
本研究に関する用語
キーワード
その他の研究ID番号
- 2026-A00019-42
個々の参加者データ (IPD) の計画
個々の参加者データ (IPD) を共有する予定はありますか?
IPD プランの説明
医薬品およびデバイス情報、研究文書
米国FDA規制医薬品の研究
米国FDA規制機器製品の研究
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