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Clinical and arthroscopic outcomes of hamstring autograft ACL reconstruction in patients aged 60 Years and older compared with middle-aged patients
⁎Corresponding author: Tsuneari Takahashi. tsuneari9@jichi.ac.jp
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Received: ,
Accepted: ,
This article was originally published by Reed Elsevier India Pvt. Ltd. and was migrated to Scientific Scholar after the change of Publisher.
Abstract
Abstract
Although Anterior cruciate ligament reconstruction (ACLR) in elderly patients has traditionally been avoided, the clinical demand for ACLR in individuals aged ≥60 years is growing recently. Nevertheless, few studies have directly compared outcomes of ACLR between elderly and middle-aged patients, especially using second-look arthroscopy. Furthermore, prior comparative studies have focused on allograft or bone–patellar tendon–bone grafts; evidence specific to hamstring autograft ACLR remains limited.
To compare clinical and arthroscopic outcomes of hamstring autograft ACLR in patients aged ≥60 years versus 40–59 years.
In this retrospective cohort, 56 patients aged ≥40 years underwent primary hamstring autograft ACLR between 2018 and 2024. Patients were grouped as middle-aged (40–59 years, n = 34) or older (≥60 years, n = 22). Outcomes included Lysholm score, Tegner activity score, anterior tibial translation, and arthroscopic cartilage status.
There were no significant differences in Lysholm score at 1 year postoperatively (82.1 ± 14.4 vs. 83.4 ± 10.9; p = 0.721) or in ΔLysholm score (27.6 ± 19.0 vs. 28.6 ± 22.7; p = 0.865) between middle-aged and older groups. Postoperative Tegner activity score also did not differ between groups (4.00 [1.00–7.00] vs. 3.00 [2.00–5.00]; p = 0.156). Second-look arthroscopic evaluations revealed no significant group differences in cartilage degeneration across all compartments. No complications or graft failures were observed in either group.
Patients aged ≥60 years demonstrated comparable clinical and arthroscopic outcomes to those of middle-aged patients following hamstring autograft ACLR. With appropriate patient selection, advanced age alone should not limit the indication for ACLR.
Keywords
Anterior cruciate ligament reconstruction
Hamstring autograft
Elderly patients
Second-look arthroscopy
Cartilage degeneration
Clinical outcomes
1 Introduction
Anterior cruciate ligament (ACL) injuries are common among young, active individuals; however, the demographic of affected patients is expanding due to the increasing participation of older adults in recreational sports and physical activity.1 As life expectancy continues to rise worldwide, orthopedic surgeons are encountering a growing number of elderly patients presenting with ACL tears. While conservative management has traditionally been favored in this population due to concerns about comorbidities, slower recovery, and potential cartilage degeneration,2 recent studies have challenged this notion by demonstrating favorable outcomes of ACL reconstruction (ACLR) in select elderly individuals.
Several reports have shown that patients over 50 years of age can achieve postoperative knee stability, functional improvement, and high satisfaction following ACLR, comparable to those seen in younger cohorts.3–5 Nevertheless, the literature remains limited regarding outcomes specifically in patients over 60 years of age,6–11 who may present distinct biological and functional characteristics compared to the middle-aged population. Moreover, few studies have incorporated objective assessments such as second-look arthroscopy or quantitative cartilage evaluation in this subgroup. Importantly, comparative studies between elderly and middle-aged patients have largely involved allograft or BTB grafts, leaving a gap regarding hamstring autograft reconstructions.
Understanding the clinical efficacy and safety of ACLR in older patients is crucial for establishing evidence-based indications and surgical decision-making. This study, therefore, aimed to evaluate the postoperative clinical and arthroscopic outcomes of ACLR in patients aged 60 years and older, compared with those aged 40–59 years. By focusing exclusively on hamstring autograft reconstructions and incorporating second-look arthroscopy, we aimed to address this evidentiary gap. We hypothesized that elderly patients would demonstrate comparable improvements in subjective scores, objective knee stability, and cartilage status without increased complication rates or graft failure.
2 Materials and methods
2.1 Patient selection
This retrospective study was conducted in the University Hospital and its affiliated institutions. The study protocol was approved by the Institutional Review Board of the hospital (Approval ID: 25‐NO.13). Since the study was retrospective, the requirement for informed consent from individual participants was waived.
The ACL injuries were diagnosed by an experienced knee surgeon based on physical examination findings, such as a positive Lachman test, or characteristic findings on magnetic resonance imaging (MRI). The following were the inclusion criteria: (1) patients with unilateral ACL injury, (2) those who underwent ACL reconstruction between April 2018 and May 2024, and (3) those who were over 40 years of age at the time of surgery. The exclusion criteria were: (1) patients who underwent revision ACL reconstruction, (2) those who had reconstruction for concomitant injury of other knee ligaments, including the medial collateral ligament, lateral collateral ligament, or posterior cruciate ligament, (3) those who underwent double-bundle ACL reconstruction, (4) those who underwent ACL reconstruction using a bone–patellar tendon–bone (BTB) graft, and (5) those who were followed up for less than one year after ACL reconstruction.
According to their age at the time of surgery, patients were divided into the Middle-aged group (M; 40–59 years) and the Older group (O; ≥60 years).
2.2 Surgical procedure
All reconstructions used hamstring autografts (semitendinosus with or without gracilis). Harvest of the ipsilateral semitendinosus tendon (ST) was performed with a tendon harvester (Smith & Nephew Endoscopy, Andover, MA). When necessary, the gracilis (GR) tendon was additionally harvested to augment the graft. The prepared graft was shaped into four strands after trimming, and each end was reinforced with tight sutures. The length of the femoral tunnel was first measured. Then, suspensory fixation devices (EndoButton CL, Smith & Nephew Endoscopy, Andover, MA) were applied to ensure insertion of at least 10 mm of the tendon bundle into the femoral tunnel. Then, polyester tape (Endobutton Tape, Smith & Nephew Endoscopy, Andover, MA) was passed through the chain-like junction and used to mechanically connect the structures.
Creation of the femoral bone tunnel was achieved through debriding the proximal end of the femoral stump with a shaver and thermal device. The anatomical footprints of the anteromedial bundle (AMB) and posterolateral bundle (PLB) were observed just posterior to the resident's ridge. Remnant tissue of ACL was debrided on the tibial side, and the tibial ACL guide was placed at the AMB footprint from the lateral to medial tibial spine. The center of the tibial insertion was determined using three surrounding landmarks—the anterior ridge, lateral groove, and intertubercular fossa—described by Tensho et al.12 A tibial tunnel measuring 8.5–9 mm in diameter was then created.
Measurements of the femoral tunnel length were obtained using both a depth gauge and the suspensory fixation device, and these values were documented. The femoral bone tunnel insertion was positioned inferior to the “over-the-top” position. To prevent posterior wall blowout, the 6-mm femoral aimer (Smith & Nephew Endoscopy, Andover, MA) was inserted through the tibial tunnel with the tibia held in varus and internal rotation (the so-called figure-four position),13 allowing creation of the femoral bone tunnel in a lower and deeper location, just posterior to the resident's ridge. A 2.4-mm guide pin was introduced through the AM portal, followed by 4.5-mm drilling and subsequent 8 mm overdrilling, thereby creating a socket-shaped femoral tunnel.
The graft was fixed to the femoral cortex by flipping the EndoButton and using a turnbuckle stapling technique. With the knee positioned at 10 degrees of flexion, the graft was tensioned to 40 N to complete fixation.14
2.3 Postoperative rehabilitation
A hinged knee brace restricting extension to minus 10° is applied for 12 weeks postoperatively. A continuous passive motion (CPM) device was used by all patients for 2 days after surgery. Partial weight-bearing is permitted for the first two weeks postoperatively. Full weight-bearing is gradually permitted up to four weeks after surgery.
Jogging is permitted at 3 months postoperatively. Return to sprinting and strenuous competitive activities are permitted at 6 months postoperatively, provided that the muscle strength of the treated knee has recovered to at least the same level as the contralateral side.15
2.4 Clinical and arthroscopic evaluations
Age, sex, affected side, body height, body weight, body mass index (BMI), pre- and postoperative Lysholm Score, pre and postoperative Tegner Activity Score were evaluated. The postoperative Tegner activity Score was recorded at the outpatient visit immediately prior to second-look arthroscopy (hereafter, the pre–second-look outpatient visit). Preoperative Lysholm Score and Lysholm score at 1 year postoperatively, and ΔLysholm score (the difference between pre- and postoperative Lysholm score) were compared between the M group and the O group. Anterior tibial translation was assessed using a KneeLax arthrometer with the knee positioned at 30° of flexion under a load of 132 N. The side-to-side difference between the uninjured and injured knees was recorded in millimeters. To reduce potential observer bias, all measurements were carried out by a single examiner who was not involved in the surgical procedure. Arthroscopic evaluation of the articular cartilage was performed at the time of the primary and second-look surgeries. These findings were categorized according to the Outerbridge classification.
2.5 Statistical analysis
Continuous variables were presented as the mean and standard deviation, whereas ordinal data were presented as the median and range. The Mann–Whitney U test was used to compare continuous and ordinal variables between groups, and Fisher's exact test was used to compare categorical variables. The Wilcoxon signed-rank test was used to compare Lysholm scores between the preoperative and 1-year postoperative evaluations, as well as the Outerbridge classification findings between the primary and second-look assesment. All statistical analyses were performed using EZR software (Saitama Medical Center, Jichi Medical University, Saitama, Japan). Statistical significance was defined as p < 0.05. A priori sample size calculation was performed using G∗Power 3.1 (Franz Paul, Kiel, Germany) to estimate the minimum number of patients for comparing ΔLysholm scores between groups. Accordingly, the minimum sample size was calculated to be 54 for α error of 0.05, β error of 0.20, and Cohen's effect size of 0.8. In the present study, 56 patients (34 in group M and 22 in group O) were included, and A post hoc analysis demonstrated a power of 80.0 % with Cohen's effect size of 0.8.
3 Results
A total of 91 patients were initially enrolled in this study. 5 patients who underwent revision ACL reconstruction, 7 patients who had concomitant reconstruction for other knee ligaments, 4 patients who underwent double-bundle ACL reconstruction, 1 patient who underwent ACL reconstruction with a bone-patellar tendon-bone graft, and 18 patients with a follow-up period of less than one year were excluded. No cases experienced postoperative complications or reoperation. Consequently, 56 patients were included in the final analysis and divided into two groups: group M (middle-aged, 40–59 years; n = 34) and group O (older, ≥60 years; n = 22).
Patient characteristics are summarized in Table 1. The mean ages of groups M and O were 48.4 ± 5.4 and 67.1 ± 3.9 years, respectively. Body height was significantly greater in group M than in group O (165.7 ± 9.8 cm in group M and 160.2 ± 7.9 cm in group O, p = 0.030). Body weight was also significantly greater in group M than in group O (66.0 ± 13.6 kg in group M and 58.1 ± 11.6 kg in group O, p = 0.028). There were no significant differences between groups in sex, laterality, BMI, preoperative Tegner activity score, time from injury to surgery, or follow-up period. Regarding injury mechanisms, sports-related injuries were more common in group M, whereas falls were more frequent in group O, without a significant difference (p = 0.154) (Table 1).
| Group M (n = 34) | Group O (n = 22) | p value | |
| Age (years) | 48.4 ± 5.4 | 67.1 ± 3.9 | <0.001 |
| Sex (male/female) | 18/16 | 8/14 | 0.279 |
| Laterality (right/left) | 23/11 | 13/9 | 0.575 |
| Body Height (cm) | 165.7 ± 9.8 | 160.2 ± 7.9 | 0.03 |
| Body Weight (kg) | 66.0 ± 13.6 | 58.1 ± 11.6 | 0.028 |
| Body Mass index | 24.1 ± 4.9 | 22.5 ± 3.6 | 0.203 |
| Preoperative Tegner Activity Score | 3.0 [1.0, 7.0] | 2.5 [0.0, 6.0] | 0.059 |
| Period from injury to surgery (month) | 6.0 [1.0, 480.0] | 5.0 [2.0, 84.0] | 0.400 |
| Follow-up period (month) | 26.0 [12.0, 72.0] | 29.0 [12.0, 72.0] | 0.893 |
| Mechanism of injury | 0.154 | ||
| -Sports | 10 | 4 | |
| -Fall | 8 | 8 | |
| -Traffic accidents | 6 | 1 | |
| -Others | 10 | 9 |
Table 2 showed surgical data. All cases underwent hamstring autograft ACL reconstruction. In both groups, the ST alone was the most commonly used graft, followed by the combined semitendinosus and gracilis tendons (ST + GR). For the medial meniscus, repair was performed in 18 cases in group M and 11 cases in group O, partial resection in 1 and 2 cases, and no procedure in 15 and 8 cases, respectively (p = 0.506). For the lateral meniscus, repair was performed in 30 cases in group M and 20 cases in group O, while resection was performed in 1 case in group M and none in group O (p = 1.00).
| Group M (n = 34) | Group O (n = 22) | p value | |
| Graft choice | 0.540 | ||
| ST alone | 25 | 15 | |
| ST + GR | 9 | 7 | |
| MM procedure | 0.596 | ||
| Repair | 17 | 12 | |
| Partial resection | 1 | 2 | |
| None | 15 | 8 | |
| LM procedure | 1.00 | ||
| Repair | 30 | 20 | |
| Resection | 1 | 0 | |
| None | 3 | 2 | |
| Preoperative SSD (mm) | 3.1 ± 3.5 | 4.3 ± 1.4 | 0.213 |
| Second-look SSD (mm) | 0.7 ± 2.5 | −0.1 ± 2.4 | 0.343 |
The side-to-side difference of anterior tibial translation was measured using a Kneelax arthrometer. No significant differences were found between groups either preoperatively (3.1 ± 3.5 mm in group M vs. 4.3 ± 1.4 mm in group O, p = 0.213) or at the time of second-look arthroscopy (0.7 ± 2.5 mm in group M vs. −0.1 ± 2.4 mm in group O, p = 0.255).
Table 3 summarizes the arthroscopic cartilage evaluation. Arthroscopic evaluation of articular cartilage with the Outerbridge classification revealed no significant differences between groups at baseline or at the time of second-look arthroscopy across all assessed compartments (Table 3).
| Variable | Group M (n = 34) | Group O (n = 22) | p value |
| Outerbridge classification – Preoperative | |||
| Patellofemoral joint | 0.0 [0.0–2.0] | 0.0 [0.0–2.0] | 0.986 |
| Medial femoral condyle | 0.0 [0.0–3.0] | 0.0 [0.0–4.0] | 0.911 |
| Lateral femoral condyle | 0.0 [0.0–4.0] | 0.0 [0.0–1.0] | 0.287 |
| Medial tibial plateau | 0.0 [0.0–1.0] | 0.0 [0.0–4.0] | 0.068 |
| Lateral tibial plateau | 0.0 [0.0–4.0] | 0.0 [0.0–1.0] | 0.380 |
| Outerbridge classification – Second-look | |||
| Patellofemoral joint | 0.0 [0.0–2.0] | 0.0 [0.0–2.0] | 0.689 |
| Medial femoral condyle | 0.0 [0.0–3.0] | 0.0 [0.0–4.0] | 0.305 |
| Lateral femoral condyle | 0.0 [0.0–3.0] | 0.0 [0.0–1.0] | 0684 |
| Medial tibial plateau | 0.0 [0.0–2.0] | 0.0 [0.0–4.0] | 0.281 |
| Lateral tibial plateau | 0.0 [0.0–2.0] | 0.0 [0.0–3.0] | 0.940 |
Table 4 summarizes the clinical outcomes. The Lysholm scores did not differ significantly between groups either preoperatively (54.5 ± 19.4 in group M and 54.9 ± 22.2 in group O, p = 0.953) or at 1 year postoperatively (82.1 ± 14.4 in group M and 83.4 ± 10.9 in group O, p = 0.721). The changes in Lysholm scores (ΔLysholm: 27.6 ± 19.0 in group M and 28.6 ± 22.7 in group O) were also comparable between groups (p = 0.865). Both groups showed significant improvement from preoperative to postoperative evaluations, with comparable degrees of improvement. Similarly, the Tegner activity score at the pre–second-look outpatient visit did not differ significantly between groups (4.00 [1.00–7.00] in group M and 3.00 [2.00–5.00] in group O; p = 0.156) (Table 4).
| Variable | Group M (n = 34) | Group O (n = 22) | p value |
| Preoperative Lysholm score | 54.5 ± 19.4 | 54.9 ± 22.2 | 0.953 |
| 1 year postoperative Lysholm score | 82.1 ± 14.4 | 83.4 ± 10.9 | 0.721 |
| ΔLysholm score | 27.6 ± 19.0 | 28.6 ± 22.7 | 0.865 |
| Postoperative Tegner Activity Score | 4.0 [1.0, 7.0] | 3.0 [2.00, 5.0] | 0.156 |
4 Discussion
This study compared clinical and arthroscopic outcomes after ACL reconstruction (ACLR) between patients aged ≥60 years and those aged 40–59 years. Both groups demonstrated significant improvement in Lysholm scores and similar levels of anterior knee stability, with no significant differences in graft integrity or cartilage degeneration at second-look arthroscopy. These findings suggest that ACLR in older adults can yield comparable results to those observed in middle-aged patients.
Several studies have reported favorable outcomes after ACLR in patients aged ≥50 years. Panisset et al. and Weng et al. demonstrated that patients over 50 showed similar postoperative function and stability compared to younger cohorts.4,5 Tan et al. in a systematic review, confirmed comparable outcomes in elderly individuals, including those over 60 3. Cao et al. further showed that radiographic osteoarthritis severity did not negatively affect clinical results.11
Importantly, Miyamoto et al. and Kurokawa et al. have documented low complication rates and no increase in graft failure among elderly patients.7,10 Our results align with these reports, as no re-ruptures or revisions occurred during follow-up. Unlike prior comparative studies that primarily used allograft or BTB grafts, our cohort included only hamstring autograft reconstructions. With second-look arthroscopy, this approach allowed for specific evaluation of hamstring autograft outcomes and enabled more precise attribution of those outcomes to this graft choice in elderly patients.
Additionally, we observed no significant differences in cartilage degeneration based on Outerbridge grading between groups, which supports the notion that ACLR does not necessarily accelerate intra-articular deterioration in elderly patients.
Another noteworthy finding is the comparable improvement in Tegner activity scores. While older patients may not return to high-impact sports, achieving preinjury activity levels remains a realistic goal. This is consistent with findings by Pohl et al. who reported sustained functional outcomes in older adults engaged in moderate physical activity.6
This study has several limitations. Its retrospective design introduces the potential for selection bias, and the follow-up period may not be sufficient to evaluate long-term outcomes such as osteoarthritis progression. In addition, the sample size was modest, although post hoc power analysis confirmed adequate statistical power. Furthermore, because all reconstructions used hamstring autografts, generalizability to other graft types (e.g., BTB or allograft) may be limited despite improved internal validity. Despite these limitations, our findings support the efficacy and safety of ACLR in selected elderly patients.
5 Conclusion
ACL reconstruction in patients aged 60 years and older resulted in significant clinical improvement and graft healing, with outcomes comparable to those in middle-aged patients. Objective knee stability, second-look arthroscopic findings, and cartilage status did not differ significantly between age groups, with no increase in complications or graft failure. These findings support the safety and effectiveness of ACL reconstruction in selected elderly patients, challenging the notion that advanced age alone should be a contraindication for surgery.
Guardian/patient's consent
Individual patient's consent was waived due to retrospective nature of this study.
Ethical approval
This study was conducted in accordance with the principles of the Declaration of Helsinki. Our Institute's Bioethics Committee for Ishibashi General Hospital Medical Research approved the study (Approval ID:2025–13) and waived the requirement for informed consent from individual participants given the retrospective study design. All patients received standard treatment.
Credit author statement
Masashi Kubota; Data curation; Formal analysis; Investigation; Roles/Writing – original draft; Writing – review & editing.
Tsuneari Takahashi; Conceptualization; Data curation; Formal analysis; Investigation; Methodology; Project administration; Supervision; Validation; Visualization; Roles/Writing – original draft; Writing – review & editing.
Mitsuharu Nakashima; Conceptualization; Data curation; Methodology; Project administration; Supervision; Validation; Writing – review & editing.
Satomi Ugawa; Conceptualization; Data curation.
Katsushi Takeshita; Conceptualization; Project administration; Writing – review & editing.
Funding statement
Not applicable.
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