A study of patients undergoing arthroscopic ACL reconstruction found a clear difference in reported sensory disturbance depending on how much hamstring tendon was harvested. Among 60 patients who had the semitendinosus tendon harvested alone, 17, or 28.3%, had altered sensation at follow-up. In the group of 60 who had both the semitendinosus and gracilis tendons harvested, 32, or 53.3%, reported the problem. The comparison produced a reported p-value of 0.005. The finding is an association from an observational study, so it does not show that removing the second tendon caused the nerve-related symptoms.
A difference in reported sensation
The researchers asked whether sensory disturbance in the saphenous-nerve distribution differed between isolated semitendinosus harvest and combined semitendinosus-plus-gracilis harvest. They had expected the isolated procedure to produce fewer sensory disturbances. The sample contained 120 patients, divided evenly between the two groups, and the study was prospective and observational.
The graft choice was not assigned at random. It was made during the operation according to the available length and girth of the semitendinosus tendon. That detail matters because the group receiving both tendons may have differed from the group receiving one for reasons tied to graft adequacy. The comparison therefore reflects outcomes between two surgical choices, rather than a randomly assigned test.
How the comparison was made
After the operation, patients answered a questionnaire and marked the areas of altered skin sensation. Evaluators who were blinded to graft details then categorized the pattern by branch involvement. At follow-up, 49 of the 120 patients, or 40.8%, had some sensory disturbance across the two groups. The results were therefore based on patient-reported symptoms and marked skin areas.
At the six-month assessment, the researchers also sorted the reported changes by which named nerve branch appeared to be involved. IPBSN alone accounted for 10% of the sample, SBSN alone for 5.8%, and involvement of both branches for 25%. The combined pattern was the most frequent of the three. The study also recorded postoperative infections and stiffness. No painful neuroma or complex regional pain syndrome was reported.
The symptoms were not all disabling
Although altered sensation was reported by 49 patients, only nine, or 7.5% of the full sample, said numbness or paraesthesia interfered with daily activities. The two figures measure different outcomes: reported sensory disturbance overall and reported interference with daily activity.
The study reported comparable baseline variables, and a single surgeon used standardized surgical technique, incision placement and tendon harvesting. However, the analysis did not use multivariable adjustment, so it did not statistically account for additional factors beyond the reported comparison.
Why the finding needs caution
The main limitation is selection. Because the gracilis decision was made intraoperatively according to semitendinosus length and girth, the non-randomized design may have introduced selection bias. In plain terms, the higher rate in the combined-harvest group cannot be attributed confidently to the extra tendon alone. The result should be read as a difference observed between groups, not as proof of a causal nerve injury.
Precision is also limited by the setting and follow-up. This was a single-centre study, and the sensory outcomes were patient-reported using questionnaires and marked skin areas. Follow-up was limited, so the study cannot say whether symptoms later resolved, persisted or changed. These limits also make it harder to know how closely the findings would apply in other settings.
Taken together, the findings point to an observed difference between the two harvest groups, while leaving causation and longer-term recovery unresolved. The study does not establish that combined harvest causes saphenous-nerve injury or show whether the reported symptoms persist beyond the six-month follow-up.
Paper data and sources
Original title: Saphenous nerve injury in ACL reconstruction: higher risk with dual hamstring harvest – an observational study
Authors: Kunheen K, Subramaniyan V, Karuppal R et al.
Journal/Repository: SICOT-J
Status: Peer-reviewed
First online: 2026-10-19
DOI: Not available
Original paper · Full text