Morphometric analysis and surgical adequacy of palmaris longus as a tendon graft. A systematic review of cadaveric studies.

INTRODUCTION: The tendon of the palmaris longus is commonly used as a tendon graft in many reconstructive surgeries. Easy to access and at proximity to the hand, the palmaris longus tendon is considered as the optimal tendon source for hand reconstructive surgery. However, and besides its inconsistency, the size of the palmaris longus tendon is reported to show variability. The aim of this study is to look for the surgical adequacy of the palmaris longus tendon by conducting a quantitative synthesis on its length and width in human populations and its correlation with the forearm length.
METHODS: Twenty-four studies met the inclusion criteria including 1761 cadaveric limbs.
RESULTS: The results were as following: (a) the mean palmaris longus tendon length was of 13.9 ± 2.6 cm, (b) the mean ratio palmaris longus tendon length/forearm length was of 0.545 ± 0.06, (c) the weighted correlation value was of 0.686, and (d) the mean palmaris longus tendon width was of 4.0 ± 1.7 mm. Only five studies reported a palmaris longus tendon length of more than 15 cm. The palmaris longus tendon length was shown to vary between ancestries; the Japanese had the shortest while Malaysian the longest palmaris longus tendons. All studies but one reported a palmaris longus tendon mean width of more than 3 mm where the minimal mean palmaris longus tendon width was of 2.5 mm.
CONCLUSION: While the requested length depends on the recipient site and/or type of reconstructive surgery, the palmaris longus tendon often met the required diameter for grafting. Our review demonstrated that while palmaris longus length varies between ancestries, its width is often adequate for grafting. In addition, the forearm length could be a good predictor of palmaris longus tendon length; such correlation could assist surgeons when planning to use palmaris longus tendon as a graft source.