Morphometric Evaluation of the Palmaris Longus Tendon and Its Adequacy for Tendon Grafting in a Turkish Cadaveric Population

AbstractObjective The Palmaris Longus (PL) tendon is a commonly used autograft in tendon reconstruction; however, the consistency of its anatomical length remains debated. This study aimed to evaluate the morphometric characteristics of the PL tendon in a Turkish cadaveric population and to determine whether it reliably meets the clinically critical graft length threshold of 120 mm (12 cm) required for delayed flexor and extensor tendon reconstructions.Methods This morphometric study included 20 adult cadaveric upper extremities. The lengths of the PL tendon and muscle belly were measured, and tendon adequacy was assessed against a predefined minimum graft length of 120 mm using a one-sample t-test. The association between muscle belly length and tendon length was analyzed using Pearson correlation.Results The mean PL tendon length was 147.58 ± 5.49 mm (range: 136.53–155.49 mm), with all specimens (100%) exceeding the 120 mm threshold. Mean tendon length was significantly greater than the reference value (p < 0.001), with a very large effect size (Cohen’s d = 5.03). The mean muscle belly length was 122.54 ± 5.02 mm. No significant correlation was observed between muscle belly length and tendon length (r = 0.010, p = 0.968).Conclusion In this cadaveric cohort, the Palmaris Longus tendon consistently provides sufficient length for standard tendon grafting procedures requiring grafts up to 12 cm. However, the absence of correlation between muscle belly size and tendon length indicates that surface anatomy is an unreliable predictor of graft adequacy. When precise graft length is critical, objective preoperative imaging should be considered.