Abstract：
We studied the pathological anatomical structures of atypical Wassel Type VI thumb duplication to provide a theoretical basis for surgical treatment. Forty-seven patients with atypical Wassel Type VI thumb duplication were treated. We found that some of cases had an ulnar thumb without an extensor tendon, or without a flexor tendon, or without both. All the ulnar metacarpal bones were abnormal to variable degrees. On-top-plasty is currently the best procedure for the treatment of this type of anomaly. Flexor tendon reconstruction is an important factor in functional reconstruction of the thumb, and keeping the pulley and sheath intact is a key step in flexor tendon reconstruction. Placing the on-top-plasty level at the distal end of the metacarpal or at the proximal phalanx depends on the presence of the flexor tendon. According to the condition of the flexor tendon, the atypical Wassel Type IV duplication can be divided into two types: the absent type and the intact type.Level of evidence: VI.
摘要：
我们研究了非典型WasselVI型拇指重复的病理解剖结构，为手术治疗提供理论依据。治疗了47例非典型WasselVI型拇指重复的患者。我们发现有些病例的尺骨拇指没有伸肌腱，或者没有屈肌腱，或者两者都没有。所有尺骨掌骨均有不同程度的异常。顶部成形术是目前治疗这种异常的最佳方法。屈指肌腱重建是拇指功能重建的重要因素,保持滑轮和护套的完整是屈肌腱重建的关键步骤。将顶部成形术水平放置在掌骨远端或近端指骨取决于屈肌腱的存在。根据屈肌腱的情况，非典型WasselIV型复制可分为两种类型：缺失型和完整型。证据级别：IV。
