Our study revealed that at one year following injury, activity levels were nearly similar to preinjury levels, and no reruptures were observed at subsequent follow-up visits (except for one patient who reinjured).
One of the most critical concerns during knee ACLR surgery is the choice of autograft. We found a statistically significant difference in graft diameter between the two groups, with a 1.28 mm mean difference in favor of the PLT. Previous research has shown a 1.7% revision rate for grafts 8.5 mm in diameter. Furthermore, for grafts between 7 and 9 mm in diameter, every 0.5 mm increase in diameter reduces the likelihood of revision by 0.82 times. 9
The impact of the autograft diameter and the possibility of re-rupture and revision have been widely investigated. Several studies have shown that a decrease in hamstring graft diameter is related to a greater rate of revision. [10]
Another study revealed an improvement in the IKDC score for each 1 mm increase in diameter and a greater revision rate for grafts less than 8 mm in diameter. [11]
Previous biomechanical research investigating the tensile strength of the same cross-sectional surface area among four-strand HTs revealed that the PLT did not significantly differ, with values of 405.8 ± 202.9 and 446.1 ± 233.2, respectively. Further investigations revealed that the PLT peak tensile strength was 2500 N, while that of the native ACL was 1725 N. [12]
The functional scores of patients in the two groups were similar across all follow-up assessments.
At the end of the 1-year period, the IKDC score was 95.22 ± 4.81 for the PLT group and 94.2 ± 2.05 for the HT group. Similarly, according to the Lysholm score, the PLT group had a score of 98.06 ± 4.62, while the HT group had a score of 97.63 ± 1.99. According to the modified Cincinnati scoring system, the PLT group scored 96.13 ± 4.78, and the HT group scored 95.75 ± 1.78. These findings suggest comparable outcomes between the two groups.
No patient in any group experienced flexion or extension loss at the end of one year.
Research conducted by Rhatomy S et al. revealed nonsignificant differences in functional scores (IKDC, Lysholm, and modified Cincinnati scores) among the groups. [13]
In their study, He, J., Tang et al. reported increased Lysholm scores in the PLT group. [14]
Angthong et al. evaluated ankle morbidity following PLT harvesting and reported potential dysfunction and concerns regarding stability. [15]
We assessed ankle function by the AOFAS-Hindfoot Scale, the FADI and the VAS-FA. The mean scores of the donor side for the AOFAS, FADI, and VAS-FA were 98.28 ± 1.61, 98.45 ± 1.4, and 99.16 ± 0.79, respectively. The contralateral side exhibited scores of 98.62 ± 1.19 for the AOFAS score, 98.74 ± 1 for the FADI score, and 99.32 ± 0.74 for the VAS-FA score. Our results showed excellent function of the donor ankle after harvesting the PLT.
Some studies have suggested that the key issue at the donor site (ankle) is ankle instability and eversion deficits during the stance phase of gait. [16]
No patient in our study expressed such issues. This is probably due to the dominant role of the peroneus brevis in ankle eversion, as well as the regeneration capacity of the harvested graft. This implies that harvesting of the peroneus longus tendon causes negligible morbidity to the ankle, and its removal has little to no impact on the joint. [17]
We assessed the thigh circumference of the affected limb before surgery and compared it to that of the healthy limb. The PLT group patients showed greater improvements concerning their preoperative values, with a 0.24 cm average difference at one year from 1.52 cm (preoperative), while the HT group had a 0.89 cm average difference at one year from 1.57 cm (preoperative). Rhatomy S et al. reported similar findings, with significantly less thigh hypotrophy in the PLT group after one year of follow-up. [13]
Harvesting of the hamstring tendons led to thigh hypotrophy, strength reduction, an imbalance in knee dynamic stability and quadriceps-hamstring asymmetry. [18]
Hence, it is clear that the PLT group had a longer recovery period, with less thigh hypotrophy.