Beutel Bryan G., Wang Janice, Taqi Muhammad
Kansas City University
King Edward Medical University, Lahore, Pakistan
Finger joint dislocations are common hand injuries that may occur at the metacarpophalangeal (MCP), proximal interphalangeal (PIP), or distal interphalangeal (DIP) joints, with varying frequency. The complex and extensive anatomy of the finger permits coordinated digital function. Each digit has 3 primary joints: the MCP, PIP, and DIP. The MCP joint is a condyloid articulation between the metacarpal and proximal phalanx. The PIP joint is a hinge joint between the proximal and middle phalanges. The DIP is also a hinge joint between the middle and distal phalanges. The range of motion of these joints allows for flexion and extension, which provides grasping, pinching, clawing, and reaching functions of the fingers. The MCP joint typically achieves 90° of flexion; the PIP and DIP often reach 100° and 80°, respectively. While flexion and extension of the digit are possible at the MCP joint, this joint can also perform adduction, abduction, and circumduction. See First Metacarpophalangeal (MCP) Joint Dorsal Dislocation. The finger joints have important soft tissue stabilizers that provide necessary support during motion. These joint stabilizers are both static and dynamic. Static stabilizers consist of noncontractile tissues, including the radial and ulnar collateral ligaments, volar plate, dorsal capsule, and sagittal bands, which surround the MCP joint. The volar plate is a crucial stabilizer, as it reinforces the volar aspect of the joint capsule and maintains stability by preventing hyperextension of the finger joints. The collateral ligaments provide stabilization against radial and ulnar (lateral) deviation of the interphalangeal joints. Sagittal bands encircle the MCP joint to keep the extensor tendon centralized. Dynamic stabilizers include extrinsic and intrinsic tendons and muscles, and 3 important dynamic stabilizers are the central slip, terminal tendon, and flexor tendons. The central slip is found dorsally and allows for PIP joint extension, while the terminal tendon inserts at the dorsal base of the distal phalanx and facilitates DIP joint extension. The flexor digitorum profundus and flexor digitorum superficialis tendons serve as additional restraints against hyperextension of the DIP and PIP joints, respectively.
手指关节脱位是常见的手部损伤，可发生于掌指（MCP）关节、近端指间（PIP）关节或远端指间（DIP）关节，其发生频率各不相同。手指复杂而广泛的解剖结构使得手指具备协调的功能。每个手指有3个主要关节：掌指关节、近端指间关节和远端指间关节。掌指关节是掌骨与近端指骨之间的髁状关节。近端指间关节是近端指骨与中间指骨之间的铰链关节。远端指间关节也是中间指骨与远端指骨之间的铰链关节。这些关节的活动范围允许手指进行屈伸，从而实现抓握、捏取、钩取和伸展功能。掌指关节通常可实现90°的屈曲；近端指间关节和远端指间关节通常分别可达100°和80°。虽然手指在掌指关节处可进行屈伸，但该关节还能进行内收、外展和环转运动。参见第一掌指关节背侧脱位。手指关节有重要的软组织稳定结构，在运动过程中提供必要的支撑。这些关节稳定结构既有静态的，也有动态的。静态稳定结构由非收缩性组织组成，包括桡侧和尺侧副韧带、掌板、背侧关节囊和矢状带，它们围绕着掌指关节。掌板是一个关键的稳定结构，因为它加强了关节囊的掌侧部分，并通过防止手指关节过度伸展来维持稳定性。副韧带可防止指间关节向桡侧和尺侧（外侧）偏斜。矢状带环绕掌指关节以保持伸肌腱位于中心位置。动态稳定结构包括外在和内在肌腱及肌肉，3个重要的动态稳定结构是中央束、终末肌腱和屈肌腱。中央束位于背侧，可实现近端指间关节伸展，而终末肌腱附着于远端指骨的背侧基部，有助于远端指间关节伸展。指深屈肌腱和指浅屈肌腱分别作为额外的限制结构，防止远端指间关节和近端指间关节过度伸展。
