A Blauth IIIB hypoplastic thumb reconstructed with a vascularised metatarso-phalangeal joint transfer: a case report with 28 years of follow up.

We reconstructed the Blauth-IIIB hypoplastic right thumb of a 16-year-old girl with a vascularised metatarso-phalangeal (MTP) joint from her second toe combined with a dorsalis-pedis flap. Abduction was provided with an abductor policis long tendon advancement, and adduction, with an extensor indicis proprius tendon transfer. Opponoplasty was performed one year later using the flexor sublimis (IV) tendon. The transferred joint remained functional and non-osteoarthritic 28 years later. Radial and palmar abduction of the reconstructed thumb was 45 degrees and 75 degrees respectively. The index, middle, and ring fingers could oppose the thumb, however she grasped small objects between her index and middle fingertips. If a pollicisation using the index finger is not accepted, the reconstruction described here is one of the surgical options. However donor-foot morbidity is not negligible. Currently, we use a proximal-interphalangeal joint transfer with an opponoplasty using an abductor digiti minimi as a first choice, when planning a reconstruction of preserved hypoplasic thumb.