This study was a prospective, randomized controlled trial conducted at Kasr Al-Ainy Medical School Hospital, Cairo University, Egypt between February 2020 and March 2022. Ethical approval was obtained from the Research Ethics Committee, Faculty of Medicine, Cairo University (Approval No CU-ORTHO-2020–043, dated January 20, 2020). A written informed consent was obtained from all patients prior to participation in the study. This study was not prospectively registered because institutional policy at the time of study initiation did not mandate registration for single-center investigator-initiated trials. Nevertheless, the trial was conducted according to CONSORT 2010 guidelines and all procedures followed the Declaration of Helsinki [20].

Randomization was performed in a 1:1 ratio using a computer-generated block sequence (block size = 4) created by an independent statistician.

Opaque, sequentially numbered sealed envelopes prepared by a study coordinator not involved in enrollment were opened intra-operatively immediately before graft harvest. Because the graft types differ, neither surgeons nor rehabilitation staff were blinded. All postoperative assessments were conducted by a senior physiotherapist blinded to group allocation and without access to operative notes. Objective outcome measures (Rolimeter, IKDC, hop test) minimized observer bias.

A total of 40 patients presenting with isolated ACL rupture were assessed for eligibility. After applying inclusion and exclusion criteria, 38 patients were enrolled to the study and randomized equally into two groups: 19 patients underwent ACLR using HT autografts, and 19 patients received BTB autografts. Baseline demographic and clinical data collected included age, sex, height, weight (used to calculate body mass index, BMI), dominant limb, symptom duration, sport type, and pre-injury activity level (Table 1).

Our inclusion criteria were, patient age between 18 and 55 years, symptomatic, MRI-confirmed complete ACL tear, no radiological evidence of osteoarthritis > grade II (Kellgren-Lawrence), normal contralateral knee, and lastly patient willingness and ability to comply with rehabilitation and follow-up

Our exclusion criteria were, patients with multiligamentous knee injury, complex meniscal root avulsions requiring additional major procedures, Previous surgery on the affected knee, contralateral knee pathology, systemic disease affecting healing (e.g., diabetes, rheumatoid arthritis), and active infection or open wounds.

Meniscal lesions identified at diagnostic arthroscopy were managed as follows: small, stable tears not requiring treatment were left in situ; tears requiring intervention (repair or partial meniscectomy) were treated at the time of ACLR and these patients were included in the study provided no other exclusion criteria were met. Patients with complex meniscal root avulsions requiring additional major procedures (e.g., root reconstruction) or multiligamentous injuries were excluded.

All procedures were performed arthroscopically under spinal or general anesthesia by senior orthopedic consultants trained in sports surgery. Standard diagnostic arthroscopy was first conducted to confirm ACL rupture and rule out any additional intra-articular injuries.

The semitendinosus and gracilis tendons were harvested through a small oblique incision over the pes anserinus. After tendons debridement and preparation, tendons were quadrupled and secured using whipstitch sutures. Anatomic single-bundle ACLR was performed. The femoral tunnel was drilled through the anteromedial portal with the knee in deep flexion (120°). Tunnel diameters were measured intraoperatively and recorded in millimetres. For hamstring grafts, the final graft diameter (quadrupled construct) was measured using a graft-sizing block and recorded. Both femoral and tibial fixation were achieved using BioComposite interference screw, Arthrex (Naples, FL, USA). The average screw diameters used were 7–8 mm; sizes were adjusted to match graft and tunnel diameters (Table 2).

A central-third BTB graft measuring approximately 10 mm wide and 25 mm long, with tibial and patellar bone plugs, was harvested through a longitudinal midline incision. Bone ends were shaped into trapezoids for anatomical fit. Tunnel placement was done similar to the HT group. Tunnel diameters were measured intraoperatively and recorded in millimeters. For BTB grafts, the minimum cross-sectional dimension of the tendon was recorded. Bone-to-bone fixation was achieved using BioComposite interference screw, Arthrex (Naples, FL, USA) of appropriate diameter. The average screw diameters used were 8–10 mm; sizes were adjusted to match graft and tunnel diameters. Special care was taken to minimize donor site morbidity.

All patients underwent the same arthroscopic technique for femoral and tibial tunnel preparation, graft passage, and tensioning (Table 2).

A standardized rehabilitation protocol was followed in both groups, designed in accordance with current evidence-based guidelines [2,3]: Day 1–7: Isometric quadriceps activation, cryotherapy, and passive ROM 0–90°, week 2–6: Progressive weight bearing with crutches; closed-chain exercises; proprioception training, month 3: Jogging and low-impact sports-specific drills if quadriceps strength ≥ 80 % of contralateral limb, month 6–8: Return to full sport allowed if hop test and strength assessments ≥ 90 % symmetric

Patients were reviewed at 1, 3, 6, and 12 months postoperatively. Primary and secondary outcomes were recorded at baseline and final 12-month follow-up for analysis.

Sample size was calculated using Power Analysis and Sample Size (PASS) software, version 15.0.5 for Windows (2017). The calculation was based on a minimal clinically important difference (MCID) of 10 points in the IKDC score [21]. as the primary outcome. Patients were allocated into two groups: Group I: BTB group, Group II: HT group. The null hypothesis assumed no difference between the two treatment modalities regarding the total postoperative IKDC score (non-inferiority design). A sample size of 17 patients per group was required to achieve 90 % power (1-β) using a one-sided two-sample unequal-variance t-test, with a margin of non-inferiority of 10 points and a significance level (α) of 0.05. To account for potential dropouts, 19 patients were enrolled per group, ensuring adequate statistical power.

Data analysis was performed by SPSS software, version 25 (SPSS Inc., PASW statistics for Windows version 25. Chicago: SPSS Inc.). Qualitative data were described using number and percent. Quantitative data were described using median (minimum and maximum) for non- normally distributed data and mean± Standard deviation for normally distributed data after testing normality using Kolmogrov-Smirnov test. Significance of the obtained results was judged at the (≤0.05) level.

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  Chi-Square, Fischer exact test were used to compare qualitative data between groups as appropriate

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  Mann Whitney U test were used to compare between 2 studied groups for non-normally distributed data.

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  Student t-test was used to compare 2 independent groups for normally distributed data.

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  Paired t-test was used to compare 2 paired readings for normally distributed data.

The primary outcome was the International Knee Documentation Committee (IKDC) subjective score at 12 months.

Secondary outcomes were ATT measured with a Rolimeter, Lachman test grade, single-hop test, Tegner activity score, and donor-site morbidity.

Anterior knee pain was assessed at each visit and documented as present or absent; no visual analogue scale (VAS) was used.

A total of 38 patients meeting inclusion criteria were randomized equally into two groups (19 HT and 19 BTB). All patients completed the minimum 12-month follow-up (100 % retention). There were no significant baseline differences in age, sex, BMI, symptom duration, or activity level between the groups (Table 1).

Mean graft diameter was 8.4 ± 0.5 mm in the HT group and 10.0 ± 0.0 mm in the BTB group (p < 0.001).Femoral and tibial tunnels averaged 8.5 ± 0.6 mm and 8.6 ± 0.5 mm for HT versus 9.9 ± 0.3 mm and 10.0 ± 0.0 mm for BTB, respectively (both p < 0.001).

All fixations used BioComposite interference screws (Arthrex, Naples, FL, USA) of matching size (Table 2).

Pre-operative ATT averaged 7.8 ± 1.2 mm (HT) and 8.0 ± 1.1 mm (BTB) (p = 0.54) (Fig. 1).

Fig. 1.

Anterior knee laxity (Rolimeter test).

Comparison of pre- and postoperative anterior tibial translation (ATT) between the hamstring tendon (HT) and bone–patellar tendon–bone (BTB) groups. Both groups demonstrated significant postoperative reduction with no statistical difference.

At 12 months, mean ATT improved to 2.3 ± 0.7 mm and 2.1 ± 0.8 mm, respectively, with no inter-group difference (mean Δ = 0.2 mm; 95 % CI −0.3 to 0.7; Cohen’s d = 0.27; p = 0.42) (Table 3).

Lachman test at final follow-up, grade 0–1 stability was observed in 94.7 % (HT) and 100 % (BTB) (p = 0.31) (Fig. 2). No patient exhibited grade 2 or 3 laxity (Table 4).

Fig. 2.

Lachman test grades.

Distribution of Lachman test grades (0–III) pre- and one-year postoperatively in both graft groups. Most patients achieved grade 0–I stability at follow-up, indicating excellent anterior stability.

Pivot Shift test (Grade 0/1):Negative/trace pivot shift: HT = 89 %, BTB = 95 %, P value = 0.3 (Table 4).

These results demonstrate equivalent graft stability at one-year follow-up (Figs. 2,3).

Fig. 3.

Pivot-shift test results.

Bar chart comparing pivot-shift grades before surgery and at one-year follow-up in the HT and BTB groups. Both grafts restored rotational stability effectively with minimal residual laxity.

The mean IKDC subjective score improved significantly within both groups (pre-op ≈ 44 → post-op ≈ 83; p < 0.001 each) ( Fig. 4).

Fig. 4.

IKDC score categories.

Comparison of International Knee Documentation Committee (IKDC) classifications pre- and postoperatively in both groups. The majority of patients improved from abnormal to normal or nearly normal categories.

At 12 months, HT = 82.6 ± 6.3 (95 % CI 78.9–86.3) vs BTB = 83.2 ± 5.9 (95 % CI 79.6–86.8) (Δ = −0.6 [95 % CI −4.9 to 3.7]; Cohen’s d = 0.10; p = 0.80).

Hop-test performance reached 94.6 ± 4.2 % (HT) and 95.2 ± 3.8 % (BTB; p = 0.67).

Median postoperative Tegner level was 6 [IQR 5–7] in both groups (p = 0.91).

Lysholm scores were not systematically recorded and are therefore not reported (Table 5).

Anterior knee pain occurred in 6 patients (31.6 %) of the BTB group and 2 (10.5 %) of the HT group (p = 0.11).

Kneeling pain was noted in 5 BTB and 1 HT patient (p = 0.08*).

There was 1 graft failure (BTB) and no infections or cyclops lesions.

Mean time to return to sport was 9.1 ± 1.6 months (BTB) and 8.8 ± 1.5 months (HT; p = 0.52).

Approximately 76 % of all patients resumed their pre-injury activity level (Fig. 5) (Table 6).

Fig. 5.

Return to sport and complications.

Summary of return-to-sport rates and postoperative complications (graft failure, infection, anterior knee pain) for the HT and BTB groups. Return-to-sport exceeded 70 % in both cohorts with low complication incidence.

No significant inter-group differences were detected for IKDC, ATT, hop test, Tegner level, or return-to-sport time.

Although anterior knee pain and kneeling discomfort were more frequent after BTB grafting, the differences did not reach statistical significance.

Both graft options achieved equivalent short-term clinical stability and functional recovery.

All clinical evaluations were performed by a blinded senior physiotherapist trained in orthopaedic outcome measurement.

This study confirms that ACLR with either HT or BTB autografts can yield excellent short-term outcomes. Given the comparable clinical performance, the choice of graft should be tailored to the patient’s lifestyle, professional demands (e.g., occupations requiring kneeling), and preference—an approach supported by systematic reviews and multi center databases [6–10,15–16,19].

This study was approved by the Research Ethics Committee of the Faculty of Medicine, Cairo University. Written informed consent was obtained from all participants prior to their inclusion in the study.

Not applicable.

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

AME: Conceptualization, Methodology, Project administration, Investigation, Supervision, Writing – original draft. WR: Investigation, Resources, Data curation. AMG: Formal analysis, Validation, Visualization. AES: Literature review (covered under Investigation), Writing – review & editing.All authors read and approved the final manuscript.