A fusion device for fusing a joint of a human or animal patient is provided, wherein the joint is a synovial joint comprising two articular surfaces and a gap therebetween, and wherein the device comprises: at least one anchorage portion (1) and at least one stabilization portion (2), wherein the anchorage portion(s) and the stabilization portion(s) constitute separate parts wherein the fusion device has an overall depth (D) parallel to an implantation direction (I), the overall depth extending from a proximal face (4) to a distal end of the fusion device, an overall width (W) and a thickness profile (T1 and T2) perpendicular to the implantation direction (I), wherein the at least one anchorage portion (1) comprises a thermoplastic liquefiable material being arranged on a surface of the anchorage portion (1) or inside a perforated sheath (52) constituting a part of the anchorage portion (1), and wherein the anchorage portions are configured to be positioned and anchored between the articular surfaces in the joint first, and the stabilization portion is capable of being mounted on the proximal ends of the anchorage portions or wherein the stabilization portion is configured to be positioned between the articular surfaces first, and the anchorage portions are capable of being pushed through or past the stabilization portion and anchored in the bone tissue beside and/or beyond the stabilization portion.ヒトまたは動物の患者の滑膜関節、特にヒトの椎間関節、指関節またはつま先関節を融合させるための融合装置は、ピン形状の２つの固定部分（１）とその間に配置された安定化部分（２）とを含む。固定部分（１）は機械的振動によって液化可能な熱可塑性材料を含む。安定化部分（２）は好ましくは骨結合を強化する機能を備えた表面を有する。固定部分（１）の厚み（Ｔ１）および深さ（Ｄ）は安定化部分（２）よりも大きい。融合装置を移植するために、融合させる関節の関節面に溝を設け、２つの対向する溝が合わさって固定部分（１）のうち一方を収容するための開口を形成する。次に、融合装置を関節面の間に押込み、機械的振動、特に超音波振動を融合装置の近位面（４）に与える。これにより、液化可能な材料は、骨組織と接触する場所で液化して骨組織に浸透し、再度凝固した後、融合装置と骨組織との間に押込嵌合接続を構成する。
