Effect of tibial remnant preservation on clinical, radiological and surgical outcomes in anterior cruciate ligament reconstruction: a retrospective single-center comparative study

Abstract

Background

Preserving the tibial remnant of a torn anterior cruciate ligament (ACL) during reconstruction is thought to enhance graft revascularisation, proprioception, and tunnel healing. However, evidence of clinical benefit remains inconsistent, and any effect size may be small. We retrospectively compared outcomes of ACL reconstruction with versus without tibial remnant preservation, explicitly accounting for potential confounders.

Methods

Between January 2018 and June 2023, 211 consecutive patients (mean age ~ 29 years) underwent primary single-bundle hamstring ACL reconstruction at our center. Group 1 (n = 79) had tibial remnant preservation determined intra-operatively based on remnant quality, and Group 2 (n = 132) underwent conventional reconstruction with complete remnant excision. Inclusion required ≥ 24 months of follow-up (mean follow-up 46 ± 17 months, range 24–72). Baseline age and sex distributions were comparable, but the injury-to-surgery interval was markedly shorter in Group 1 (4.6 ± 1.2 months) than in Group 2 (8.4 ± 2.2 months). We compared demographic, surgical, and clinical outcomes. Primary outcomes included knee stability (Lachman and pivot-shift tests), functional scores (Lysholm knee score), radiographic tibial/femoral tunnel widening, graft failure requiring revision, and graft survival. Continuous variables were analyzed with independent t-tests or Mann–Whitney U tests and are reported as mean differences with 95% confidence intervals (CIs). Categorical variables were compared with chi-square or Fisher’s exact tests and reported as risk differences with 95% CIs.

Results

Age (28.9 ± 6.4 vs. 29.3 ± 6.1 years) and follow-up duration (46.2 ± 16.8 vs. 45.3 ± 17.4 months) were similar between groups. The time from injury to surgery differed by − 3.8 months (95% CI − 4.3 to − 3.3), reflecting earlier surgery in the remnant-preserved group. Postoperative Lysholm scores were high in both groups and did not differ (mean difference = 1.4 points, 95% CI − 0.18 to 2.98; p = 0.083). At final follow-up (mean ~ 46 months), negative Lachman tests were more frequent in Group 1 (89.9%) than in Group 2 (74.2%), an absolute difference of 15.6% points (95% CI 5.6 to 25.6; p = 0.007). Similarly, the pivot-shift test was negative in 94.9% of Group 1 versus 83.8% of Group 2 (difference = 10.8% points, 95% CI 3.0 to 18.7; p = 0.026). Mean tibial tunnel widening was 0.30 mm less in Group 1 (difference = − 0.30 mm, 95% CI − 0.42 to − 0.18; p < 0.001), and the risk of > 2 mm tibial widening was 5.1% in Group 1 versus 15.2% in Group 2 (difference = − 10.1% points, 95% CI − 17.9 to − 2.3; p = 0.026). Revision ACL surgery was required in 2 patients (2.5%) in Group 1 and 14 patients (10.6%) in Group 2 (risk difference = − 8.1% points, 95% CI − 14.4 to − 1.8; p = 0.034). At final follow-up, Kaplan–Meier analysis showed higher revision-free survival in Group 1 than Group 2 (97.4% vs. 89.4%; log-rank p = 0.031). In a Cox regression model, tibial remnant preservation had a hazard ratio of 0.30 (95% CI 0.06–1.47), suggesting a lower revision risk; however, the confidence interval included 1, indicating this trend did not reach statistical significance.

Conclusions

Preservation of a well-quality tibial ACL remnant was associated with better objective knee stability and a lower early revision rate compared with complete remnant excision, while subjective functional scores were similar. Because the study was retrospective and the remnant-preserved group underwent earlier surgery, these findings should be interpreted with caution. Remnant preservation may be a useful adjunct when feasible, but prospective randomized studies controlling for confounders are required to determine causality.

Background

Anterior cruciate ligament (ACL) injuries are common among young, active individuals and may lead to chronic knee instability and early osteoarthritis [1]. Standard arthroscopic reconstruction restores knee stability and allows return to sport, yet some patients experience residual laxity or graft failure [1, 2]. Consequently, surgical modifications aimed at promoting graft healing and stability have been proposed [3]. One such modification involves preserving the tibial stump of the torn ACL. The remnant contains vascular channels and mechanoreceptors [4]; its synovial envelope may facilitate graft revascularisation [5], early ligamentisation [6], proprioceptive feedback [7], and bone tunnel healing [8]. However, remnant preservation increases technical complexity, can impair visualization, and carries a risk of cyclops lesion if bulky tissue is left behind [9, 10]. Reported clinical benefits of remnant preservation are variable [11–13], perhaps reflecting heterogeneity in remnant quality, surgical technique, and patient selection [3]. We sought to clarify the effect of tibial remnant preservation on clinical, radiological, and surgical outcomes in a contemporary cohort.

Objective and hypothesis

We hypothesized that, compared with complete remnant excision, preservation of a robust tibial remnant would be associated with improved objective knee stability and reduced graft failure, without compromising patient-reported outcomes. Because our study was retrospective and allocation depended on intra-operative remnant quality, we anticipated that baseline differences (e.g. injury-to-surgery interval) could confound the observed effects; therefore, findings were interpreted cautiously.

Methods

Study design and patient selection

This single-center retrospective cohort study was approved by the Ethics Committee of SBU Gazi Yaşargil Training and Research Hospital (Decision No. 66; Date: 24/05/2024) and conducted in accordance with the Declaration of Helsinki. The study was not registered as a clinical trial (registration not applicable). We reviewed medical records of patients who underwent primary arthroscopic ACL reconstruction between January 2018 and June 2023. Inclusion criteria were: age ≥ 18 years, primary (first-time) ACL reconstruction, and at least 24 months of post-operative follow-up. Patients with concomitant meniscal pathology were included only if they had simple longitudinal or horizontal tears (including ramp lesions) amenable to arthroscopic repair. Exclusion criteria were: concomitant multi-ligament injury (involving collateral ligaments, posterolateral corner, or posterior cruciate ligament), advanced chondral damage (Outerbridge grade II–IV) [14], systemic connective tissue disease, complex or irreparable meniscal tears, insufficient follow-up, and postoperative deep infection. Of 318 eligible cases, 107 were excluded, leaving 211 participants for analysis. We did not perform an a priori sample size calculation; the study cohort represents a consecutive convenience sample of all eligible patients in the timeframe.

Group allocation and surgical technique

Group 1 (remnant-preserved) comprised patients in whom intra-operative assessment identified a continuous tibial remnant of adequate volume (≥ 30% of the original stump, corresponding to Crain classification type 1–2 [15]) with intact synovial coverage (Fig. 1). In these cases, the remnant tissue was preserved by carefully trimming only loose fiber strands that might cause intercondylar impingement, and drilling the tibial tunnel centrally through the remnant at low speed to avoid disrupting the remnant sheath (Fig. 2). The graft was then passed through the synovial sleeve formed by the remnant (Fig. 3), and full knee extension was confirmed arthroscopically at the end of surgery (Fig. 4). Group 2 (remnant-removed) consisted of patients in whom the remnant was absent or was deemed non-viable and thus completely debrided. All patients underwent single-bundle ACL reconstruction using a quadrupled ipsilateral semitendinosus–gracilis autograft fixed with a cortical suspension device on the femoral side and a bioabsorbable interference screw on the tibial side. An additional tibial staple was used at the surgeon’s discretion. The choice to preserve the remnant was subjective and could introduce selection bias. No attempts were made to balance groups via randomization or statistical adjustment, because the necessary data on potential confounders were not routinely collected.

Fig. 1.

Intraoperative arthroscopic view of the preserved tibial stump

Fig. 2.

Tibial tunnel drilling through the remnant

Fig. 3.

Graft passage through synovial remnant sleeve

Fig. 4.

Final graft positioning and control

Rehabilitation protocol and follow-up

All patients followed the same standardized, evidence-based rehabilitation protocol [16–19] under the supervision of a dedicated physiotherapy team. Immediate postoperative goals were to control pain and swelling, achieve full knee extension, and initiate quadriceps activation. Passive and assisted active range-of-motion exercises commenced on the first postoperative day. Partial weight-bearing with crutches was permitted for approximately 2–3 weeks, advancing to full weight-bearing as tolerated. Strengthening, neuromuscular training, and proprioceptive exercises were gradually introduced over the ensuing weeks. Light jogging and sport-specific drills were allowed after 3 months, and return to pivoting sports was generally permitted after 6 months, contingent on a normal stability examination and adequate muscle strength. Follow-up evaluations were scheduled at 6 weeks, 3 months, 6 months, 12 months, and then annually. At each follow-up, patients were assessed for reinjury and underwent a standardized knee examination (including Lachman test, pivot-shift test, and goniometric range-of-motion measurement) and completed the Lysholm knee score questionnaire. Standard anteroposterior and lateral knee radiographs were obtained in the immediate postoperative period and at final follow-up to measure femoral and tibial tunnel diameters. The same two fellowship-trained orthopaedic surgeons performed all clinical examinations. Radiographic tunnel measurements were performed twice by one investigator, and an intraclass correlation coefficient of 0.93 demonstrated excellent intra-observer reliability; inter-observer reliability was not assessed and is acknowledged as a limitation.

Outcome definitions

Primary outcomes were objective knee stability, functional recovery, tunnel widening, and graft failure. The Lachman test was graded as negative (≤ 3 mm side-to-side difference with a firm end-point) or positive (> 3 mm anterior translation or a soft end-point). The pivot-shift test was recorded as negative (no subluxation or giving way) or positive (palpable clunk or visible giving-way). Active knee flexion and extension were measured with a goniometer; any terminal extension deficit was noted. Functional outcome was assessed using the Lysholm Knee Score (0–100 points). Radiographic tunnel widening was defined as the increase in tunnel diameter (mm) between the immediate postoperative and final follow-up radiographs; clinically significant tunnel widening was defined a priori as > 2 mm [10]. Graft failure was defined as symptomatic knee instability with clinical findings consistent with ACL rupture and/or MRI evidence of graft disruption, in a patient who proceeded to revision ACL surgery. Complications such as cyclops lesion, deep infection, deep venous thrombosis, and neurovascular injury were recorded.

Statistical analysis

All statistical analyses were performed using IBM SPSS Statistics (Version 25; IBM Corp., Armonk, NY, USA). Continuous variables are reported as mean ± standard deviation (SD) and were compared between groups using independent-samples t-tests (if normally distributed) or the Mann–Whitney U test (if distributional assumptions were violated). For key continuous outcomes, mean differences with 95% CIs were calculated using pooled SDs. Categorical variables are presented as counts and percentages; group comparisons used the chi-square test or Fisher’s exact test, as appropriate. Risk differences (Group 1 minus Group 2) with 95% CIs were calculated for categorical outcomes using the standard error of a proportion. Revision-free graft survival was estimated using the Kaplan–Meier method (censoring each patient at their last follow-up contact) and compared between groups with the log-rank test. A Cox proportional hazards model was used to evaluate the association between remnant preservation and revision risk; the result is presented as a hazard ratio (HR) with a 95% CI. Statistical significance was defined as p < 0.05. Because the study was non-randomized and potential confounders (e.g. generalized joint hypermobility, activity level, return-to-sport timing) were not systematically recorded, no multivariable adjustment was performed.

Results

Patient characteristics

A total of 211 patients met the inclusion criteria, with 79 patients in Group 1 and 132 in Group 2. Baseline characteristics are summarized in Table 1. The groups were comparable in age and sex distribution: the majority of patients were male (84.8% in Group 1 and 85.6% in Group 2). The mean follow-up duration was approximately 46 months in both groups (46.2 ± 16.8 months for Group 1 vs. 45.3 ± 17.4 months for Group 2; mean difference 0.9 months, 95% CI − 3.9 to 5.7; p = 0.75). Notably, the time from injury to surgery was markedly shorter in Group 1 (mean 4.6 ± 1.2 months) than in Group 2 (8.4 ± 2.2 months), with a mean between-group difference of − 3.8 months (95% CI − 4.26 to − 3.34; p < 0.001). Meniscal tears requiring repair (simple longitudinal or horizontal tears, including ramp lesions) were present in roughly one-third of patients in each group (32.7% vs. 31.1%; risk difference 1.6% points, 95% CI − 11.2 to 14.9; p = 0.78). All patients in both groups received semitendinosus + gracilis hamstring autografts (no graft type variation).

Table 1.

Baseline characteristics of the study groups (mean ± SD or count and percentage, with between-group differences and 95% CIs)

Characteristic	Remnant-preserved (n = 79)	Remnant-removed (n = 132)	Between-group difference (95% CI)	p-value
Age (years)	28.9 ± 6.4	29.3 ± 6.1	–0.4 (–2.15 to 1.35)	0.63
Sex (male/female)	67/12 (84.8% male)	113/19 (85.6% male)	–0.8% points (–9.2 to 7.6)	0.89
Follow-up duration (months)	46.2 ± 16.8	45.3 ± 17.4	0.9 (–3.85 to 5.65)	0.75
Injury-to-surgery interval (months)	4.6 ± 1.2	8.4 ± 2.2	–3.8 (–4.26 to − 3.34)	< 0.001
Meniscal tear repaired	26/79 (32.7%)	41/132 (31.1%)	1.6% points (–11.2 to 14.9)	0.78

Clinical and radiological outcomes

The final follow-up evaluation occurred at a mean of approximately 46 months post-surgery (range 24–72 months). Table 2 presents the key functional and objective stability outcomes. Mean Lysholm knee scores at final follow-up were high in both cohorts (91.6 ± 5.4 in Group 1 vs. 90.2 ± 6.1 in Group 2) and did not differ significantly (mean difference = 1.4 points, 95% CI − 0.18 to 2.98; p = 0.083). In contrast, objective knee stability favored the remnant-preservation group. A normal Lachman test (grade 0, indicating ≤ 3 mm translation) was observed in 89.9% of Group 1 compared with 74.2% of Group 2, an absolute risk difference of 15.6% points (95% CI 5.6 to 25.6; p = 0.007). Similarly, a negative pivot-shift test was noted in 94.9% of Group 1 versus 83.8% of Group 2 (difference = 10.8% points, 95% CI 3.0 to 18.7; p = 0.026). Active knee range of motion was excellent in both groups: mean maximal flexion was 132.4° ± 4.7° in Group 1 and 131.7° ± 5.2° in Group 2 (mean difference = 0.7°, 95% CI − 0.66 to 2.06; p = 0.34). All patients achieved full knee extension at final follow-up, except for one case in Group 1 who had a slight extension loss due to a cyclops lesion. No significant arthrofibrosis or chronic extension deficits were observed in either group.

Table 2.

Postoperative functional, stability, and radiographic outcomes at final follow-up (mean ± SD or % of patients, with between-group differences and 95% CIs)

Outcome	Remnant-preserved (n = 79)	Remnant-removed (n = 132)	Between-group difference (95% CI)	p-value
Lysholm score (points)	91.6 ± 5.4	90.2 ± 6.1	1.4 (–0.18 to 2.98)	0.083
Lachman test negative	71/79 (89.9%)	98/132 (74.2%)	15.6% points (5.6 to 25.6)	0.007
Pivot-shift test negative	75/79 (94.9%)	111/132 (83.8%)	10.8% points (3.0 to 18.7)	0.026
Active flexion (degrees)	132.4° ± 4.7°	131.7° ± 5.2°	0.7° (–0.66 to 2.06)	0.34
Tibial tunnel widening (mm)	1.0 ± 0.4	1.3 ± 0.5	–0.30 mm (–0.42 to − 0.18)	< 0.001
Tibial widening > 2 mm	4/79 (5.1%)	20/132 (15.2%)	–10.1% points (–17.9 to − 2.3)	0.026
Femoral tunnel widening (mm)	1.3 ± 0.5	1.4 ± 0.6	–0.1 mm (–0.26 to 0.06)	0.19
Revision ACL surgery	2/79 (2.5%)	14/132 (10.6%)	–8.1% points (–14.4 to − 1.8)	0.034

Radiographically, tibial tunnel widening was significantly less pronounced in the remnant-preserved group. Mean tibial tunnel enlargement from immediately post-op to final follow-up was 1.0 ± 0.4 mm in Group 1 versus 1.3 ± 0.5 mm in Group 2, with a mean difference of − 0.30 mm (95% CI − 0.42 to − 0.18; p < 0.001). Moreover, clinically significant tibial tunnel widening (> 2 mm) occurred in 5.1% of Group 1 (4 of 79 patients) compared to 15.2% of Group 2 (20 of 132 patients), yielding an absolute risk difference of − 10.1% points (95% CI − 17.9 to − 2.3; p = 0.026). Femoral tunnel widening did not differ between the techniques (mean 1.3 ± 0.5 mm in Group 1 vs. 1.4 ± 0.6 mm in Group 2; p = 0.19).

Postoperative complications were recorded to ensure thorough safety reporting. One patient in Group 1 developed a cyclops lesion (fibrous nodule in the intercondylar notch causing extension loss), which was successfully treated with arthroscopic debridement. One patient in each group experienced a deep surgical site infection in the early postoperative period; these two patients required graft removal and antibiotic therapy and were excluded from the final outcome analysis (as infection-related graft failure could confound revision risk assessment). Deep venous thrombosis (DVT) occurred in three patients (1 in Group 1, 2 in Group 2); all DVTs were managed effectively with medical anticoagulation, and none of these patients required surgical intervention. No neurovascular injuries were observed in either group.

Graft failures and survival analysis

In total, 2 patients (2.5%) in Group 1 and 14 patients (10.6%) in Group 2 experienced graft failure leading to revision ACL surgery. This corresponds to an absolute risk reduction of 8.1% points for the remnant-preservation technique (95% CI − 14.4 to − 1.8; p = 0.034 by Fisher’s exact test). Among the failed cases, the mean time to revision was 13.4 ± 6.2 months (range 8–20 months) in Group 1 and 15.2 ± 5.6 months (range 7–25 months) in Group 2. Using all available follow-up data with appropriate censoring, the Kaplan–Meier survival analysis demonstrated that revision-free survival remained higher in Group 1 than in Group 2 by the end of the follow-up period. At final follow-up, the estimated cumulative graft survival rate was 97.4% in the remnant-preserved group versus 89.4% in the remnant-removed group (p = 0.031 by log-rank test). In an unadjusted Cox proportional hazards model, tibial remnant preservation was associated with a hazard ratio of 0.30 (95% CI 0.06–1.47) for revision, indicating a trend toward lower graft failure risk. However, the wide confidence interval crossing unity suggests that this difference did not reach statistical significance and should be interpreted with caution. No multivariable survival analysis was performed, as data on potential confounding variables (such as return-to-sport timing, patient activity level, and generalized joint laxity) were not available.

Discussion

This retrospective analysis suggests that preserving a substantial tibial ACL remnant during reconstruction may confer certain mechanical advantages without compromising patient-reported outcomes. We observed clinically meaningful improvements in objective stability with remnant preservation: the rates of negative Lachman and pivot-shift tests were notably higher in Group 1. Tibial tunnel widening was also reduced by approximately 0.3 mm on average, and the proportion of patients with > 2 mm of tunnel enlargement was markedly lower in the remnant-preserved group. Furthermore, the revision surgery rate in Group 1 (2.5%) was less than one-quarter of that in Group 2 (10.6%) at mid-term follow-up.

Interpretation of key findings

The stability benefits we observed with remnant preservation align with findings from several prior investigations. A recent meta-analysis reported that ACL reconstructions with remnant-preserving technique were associated with improved anteroposterior laxity (smaller KT-1000 side-to-side differences) and fewer positive pivot-shift exams, without significant differences in patient-reported scores such as Lysholm or IKDC (International Knee Documentation Committee) [20–22]. Our results corroborate this pattern: objective knee stability was improved in the remnant group, whereas subjective Lysholm scores were comparable between techniques. The absolute between-group differences (approximately 15.6% more patients with a normal Lachman and 10.8% more with a normal pivot-shift in Group 1) are likely attributable to the mechanical support provided by the retained remnant. In vitro studies have suggested that residual ACL fibers can act as a biological scaffold or brace, helping to limit graft micromotion and shielding the healing graft from excessive strain in the early postoperative period [9, 10].

The reduction in tibial tunnel widening observed with remnant preservation is consistent with the notion that the synovial sheath of the remnant may protect the graft–bone interface from synovial fluid and inflammatory mediators [10]. A recent meta-analysis similarly found significantly less tibial tunnel enlargement when the remnant was preserved [23]. Less tunnel widening could translate into improved long-term graft incorporation and might partly explain the lower revision rate we observed in Group 1. It is conceivable that a better-preserved graft–bone interface and enhanced biological healing lower the risk of graft failure over time.

Limitations and potential confounding

Despite the apparent benefits noted, several important limitations temper our conclusions. First, the study design was retrospective and non-randomized. Surgeons decided intra-operatively whether to preserve the remnant based on subjective assessment, introducing potential selection bias. Patients in the remnant-preservation group had a significantly shorter injury-to-surgery interval, reflecting earlier surgical timing. Earlier surgery is known to be associated with better remnant tissue quality and potentially improved outcomes; thus, we cannot disentangle the effect of shorter time-to-surgery from the effect of remnant preservation itself. Second, we lacked data on many variables that might influence outcomes. Factors such as generalized joint hypermobility (e.g. Beighton score), graft diameter, patient activity level, post-operative rehabilitation adherence, and timing of return to sport were not systematically recorded. Without these data, no multivariable adjustment could be performed, and we cannot exclude the possibility that these unmeasured confounders contributed to the observed differences in stability or revision rates. Third, knee stability was assessed by manual clinical examination without instrumented laxity measurements (such as a KT-1000 arthrometer). Although the same experienced examiners performed all tests, the subjective grading of Lachman and pivot-shift introduces measurement uncertainty and potential intra-observer variability. Fourth, radiographic tunnel widening was measured by a single observer. We demonstrated excellent intra-observer reliability for these measurements, but inter-observer reliability was not evaluated, leaving room for measurement bias. Fifth, the follow-up duration (mean roughly 46 months, with a maximum of 72 months) may be insufficient to capture all potential late graft failures. A longer surveillance period might reveal additional failures that did not manifest within our follow-up window. Finally, no formal sample size or power calculation was conducted prior to the study. The analysis included all eligible patients available in our database, and while some differences (e.g. stability outcomes) were statistically significant and likely clinically meaningful, the study may still be underpowered to detect more subtle between-group differences, especially for relatively rare outcomes like graft failure.

Clinical implications

In light of these limitations, our findings should be interpreted as showing an association rather than proving a causal benefit of remnant preservation. Nevertheless, the results suggest that when a robust remnant is present, preserving it may offer real mechanical and biological advantages. Surgeons who opt for remnant-preserving ACL reconstruction should exercise meticulous technique: careful debridement of frayed or loose fibers is essential to minimize the risk of cyclops lesion (in our series, only one such lesion occurred out of 79 remnant-preserved cases). It should also be kept in mind that remnant tissue can sometimes obscure visualization and make precise tunnel placement more challenging. Thus, this technique may be best suited for experienced surgeons who are familiar with remnant anatomy and comfortable navigating around retained tissue. As remnant preservation gains interest, it is important that surgeons also collect data on potential confounding factors (patient activity levels, ligament laxity, etc.) and patient-reported outcome measures, to better contextualize the results in real-world settings.

Future directions

Prospective randomized controlled trials are needed to definitively assess the impact of tibial remnant preservation on ACL reconstruction outcomes. Future studies should stratify or randomize patients based on remnant quality and size, collect detailed baseline characteristics (e.g. Beighton scores for generalized laxity, pre-injury activity level), and incorporate objective laxity measurements. Extended longitudinal follow-up beyond five years will be important to determine whether the early stability advantages we observed translate into sustained graft survival benefits and lower long-term osteoarthritis risk. In addition, research into biological augmentations—such as quantifying graft revascularization or maturation via imaging or biomarkers—could illuminate the mechanisms by which remnant preservation might improve healing [24, 25].

Conclusions

In this retrospective single-center cohort study, preservation of a high-quality tibial ACL remnant was associated with better objective knee stability and a lower early revision rate compared with complete remnant excision, while subjective functional outcomes (Lysholm scores) were comparable between the techniques. Because allocation was non-randomized and the remnant-preserved group underwent surgery sooner after injury, residual confounding cannot be excluded. These findings therefore suggest, rather than conclusively demonstrate, that remnant preservation may be a beneficial adjunct when conditions are favorable. Randomized controlled trials with rigorous control of confounders are needed to confirm these associations and guide evidence-based practice.

Authors’ contributions

CA conceived the study, supervised data collection, and drafted the manuscript. AY and HY collected patient data and performed clinical assessments. HY conducted the statistical analysis. KD and MA assisted with surgical procedures and interpreted the radiological data. MŞ (M. Akif Şahin) critically revised the manuscript for important intellectual content. All authors read and approved the final version of the manuscript.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Data availability

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

Declarations

Ethics approval and consent to participate

This study was approved by the Ethics Committee of SBU Gazi Yaşargil Training and Research Hospital (Decision No. 66; Date 24/05/2024). The study was not registered as a clinical trial (registration not applicable). All patients provided written informed consent for their data to be included in an institutional outcomes database and for retrospective analysis.

Consent for publication

Not applicable. This study does not contain any individual person’s identifiable data.

Competing interests

The authors declare no competing interests.