Revisiting the management of Manske Type 3B and 4 thumb hypoplasia

Abstract

The traditional management of Manske 3B and 4 thumbs is index finger pollicization. Recently, the transfer of composite tissues from the foot to reconstruct the thumb or the carpometacarpal joint has allowed the preservation of a five-digit hand. Concerns remained about the donor site and also the limited functional and cosmetic outcomes that could be achieved. This article challenges the existing dogma in the management of hypoplastic thumbs, that pollicization should always be the reference standard. We describe the evolution of techniques with free vascularized metatarsal transfer, our refinements and our proposal for a new classification system that accommodates these modifications. With increased experience, acceptable outcomes that are comparable with pollicization can be achieved.

On the classification of thumb hypoplasia and assessment of management outcomes

“…Granted, there may be some residual metacarpal head in radiographs, but this is minimal, is confined to the floating digit and the metacarpophalangeal joint is non-functional. Liu et al (2021) offer elegant reconstructive procedures for Grades 3 and 4, as have others previously. However, management options for their subgroups 3B, C and D are similar despite some alteration in weight of preference for specific procedures.…”

“…Grade 3 thumbs have no CMC joint and were subdivided by Buck-Gramcko in 1993 according to the amount of metacarpal absent (Figure 1) (Buck-Gramcko, 2002;Tonkin, 2014). Liu et al (2021) have followed the advice of Manske and McCarroll (1992) and have persisted with their subgroup of Grade 3A with an intact CMC joint. I think that this is unfortunate.…”

“…The desire to maintain five digits is powerful indeed and correctly so. Subjective opinions of patients, parents and medical staff are very helpful in determining optimal procedures and in assessing outcomes of surgical management, as are the objective measurements used by Liu et al (2021) and others.…”

Donor site reconstruction by adjacent half-width metatarsal after full-width metatarsal transfer for metacarpal reconstruction in severe thumb hypoplasia

“…According to the modified classification (JST classification) we proposed, there were three, eight, four, and five thumbs classified as type IIIB, type IIIC, type IIID, and type IV, respectively. [6] Fifteen NF4MT grafts (eight left and seven right) and five VF2MFT grafts (three left and two right) were harvested in the first metacarpal reconstruction procedures [Supplementary Table 1, http://links.lww.com/CM9/B398]. Abnormal toes were observed in four patients [Supplementary Table 1, http://links.lww.com/CM9/B398 and Supplementary Figure 3, http://links.lww.com/CM9/B398].…”

“…Thirteen, five, and two parents respectively answered very satisfied, somewhat satisfied, and fair to the function of donor foot; the mean score was MT for reconstruction of the severely hypoplastic thumb is an increasingly popular option. [6] A minimal donor site may provide a stronger impetus for parents to choose metatarsal reconstruction over a pollicization. However, few studies have specifically examined the outcome and parental satisfaction of the donor foot.…”