Anterior cruciate ligament (ACL) injuries represent one of the most common and debilitating conditions encountered in orthopedic and sports medicine. The ACL plays a crucial role in maintaining knee joint stability, and its rupture often necessitates surgical reconstruction to restore normal function and prevent long-term complications, such as osteoarthritis and meniscus damage ^[1]. Over the past few decades, various autograft options have been explored for ACL reconstruction, including the bone-patellar tendon-bone graft and hamstring tendon (HT) graft. While these grafts have demonstrated favorable outcomes, concerns regarding donor site morbidity, such as anterior knee pain and muscle weakness, have driven the search for alternative graft sources ^[2]. The peroneus longus tendon (PLT) has emerged as a promising autograft option for ACL reconstruction. Several studies have highlighted the biomechanical strength of the PLT, noting its comparable tensile properties to the native ACL and other commonly used grafts ^[3,4]. In addition, the PLT offers the advantage of minimal donor site morbidity and reduced risk of quadriceps or hamstring muscle weakness ^[5]. Recent clinical studies and systematic reviews have demonstrated that ACL reconstruction using PLT results in satisfactory knee stability and functional outcomes, comparable to or exceeding those achieved with traditional autografts ^[6,7]. Research by Agarwal et al. and He et al. has shown that patients undergoing PLT-based ACL reconstruction experience significant improvements in international knee documentation committee and Lysholm scores, with no significant differences in donor site pain or functional deficits ^[3,4]. Furthermore, comparative studies have indicated that PLT grafts provide larger graft diameters, which may contribute to enhanced graft strength and longevity ^[8,9]. This attribute makes the PLT particularly suitable for patients with larger body frames or those undergoing revision ACL reconstruction ^[10]. Despite these promising findings, some studies have reported minor ankle-related complications, such as reduced eversion and plantarflexion strength at the donor site ^[11,12]. However, these effects are generally transient and do not significantly impact overall patient satisfaction or return to physical activity ^[13]. In light of the growing body of evidence, the PLT is increasingly being recognized as a viable and effective alternative for ACL reconstruction, offering comparable outcomes to traditional autografts while mitigating the risk of donor site complications ^[12,13]. The objective of the study is to assess the clinical and functional assessment of donor site ankle morbidity after harvesting PLT graft for arthroscopic ACL reconstruction.

The retrospective observational study was conducted at the Department of Orthopaedics of a Government Medical College and Hospital in India between February 2023 and October 2024. The study aimed to evaluate the donor site ankle morbidity in patients undergoing arthroscopic ACL reconstruction using PLT graft.

Ethical considerations

The study protocol was reviewed and approved by the Institutional Research Committee. The study included 56 patients with symptomatic partial or complete ACL tears requiring arthroscopic reconstruction who underwent surgery in the specified duration. Patients were selected based on specific inclusion criteria: They were ages between 18 and 50 years and whose follow up data was available. Exclusion criteria included pre-existing ankle deformity, professional athletes, history of ankle or foot pathology, prior ankle surgeries, and patients with systemic illnesses that could affect healing or rehabilitation. Informed consent was obtained from all participants, who were fully briefed on the study’s objectives, procedures, risks, and benefits. The methodology involved preoperative, intraoperative, and postoperative assessments to evaluate donor site ankle morbidity. Clinical evaluation included the use of the visual analogue scale for foot and ankle (VAS-FA) score to assess pain and functional status, and the American orthopaedic foot and ankle society (AOFAS) score for a comprehensive ankle function evaluation. All patients underwent arthroscopic ACL reconstruction using a PLT graft (Fig. 1).

Surgical procedure

The surgical procedure involves harvesting the autogenous PLT through a vertical incision near the distal fibula. The tendon is exposed, and the distal portion is sutured to the peroneus brevis tendon. The proximal end is sutured with a non-absorbable suture, then harvested using a tendon stripper. The graft is pre-tensioned, tripled for thickness, and sized for the femoral and tibial tunnels. Arthroscopic portals (anterolateral, anteromedial, posteromedial, and superolateral) are used for visualization and preparation of the femoral and tibial tunnels. The graft is passed through the tunnels and fixed with Endobutton and interference screw. Postoperative rehabilitation included physiotherapy and strengthening exercises, with weight-bearing restrictions for the first 2 weeks, followed by progressive loading. Follow-up evaluations were conducted at 14 days, 4 weeks, 12 weeks, and 6 months postoperatively, during which VAS-FA and AOFAS scores were recorded to assess functional outcomes and donor site morbidity. Outcome assessments were conducted by independent evaluators who were blinded to the surgical details and patient grouping. This blinding was maintained throughout the follow-up period to minimize observer and performance bias, particularly during the assessment of subjective outcome measures such as VAS-FA and AOFAS scores. Descriptive statistics were used to summarize baseline characteristics, and repeated measures analysis of variance (ANOVA) was performed to assess changes in VAS-FA and AOFAS scores over time. A P < 0.05 was considered statistically significant. Wilcoxon signed-rank tests were used for paired non-parametric comparisons between timepoints, while repeated measures ANOVA was applied to assess overall trends across multiple timepoints with approximately normal distributions.

The study included participants with a mean age of 36.8 years (± 6.98) and an average injury duration of 13.3 months (± 4.35). Full weight-bearing was attained at an average of 6.43 weeks (± 0.87), with a mean graft size of 8.34 mm (± 0.695). Males constituted 51.8% of the study cohort. A total of thirty-seven participants (66.1%) reported experiencing complications following tendon harvesting, with twenty-seven individuals indicating mild pain and others reporting swelling at the donor site. Table 1 presents the preoperative visual analog scale for functional assessment (VAS-FA) scores, which averaged 7.52 ± 0.84, indicating a considerable level of discomfort at the donor site. Postoperative scores demonstrated improvement at all follow-up intervals: 4.87 ± 0.76 at 14 days, 4.51 ± 0.63 at 4 weeks, 3.41 ± 0.37 at 12 weeks, and 2.05 ± 0.41 at 6 months. Wilcoxon signed-rank tests revealed statistically significant improvements at each time point (P < 0.001), thereby reflecting a reduction in donor site morbidity.

As presented in Table 2, the average preoperative AOFAS scores were 54.8 ± 3.28, which suggests the presence of functional limitations in the donor ankle. Postoperative assessments demonstrated significant improvements at all evaluated time points: 14 days (61.0 ± 4.76), 4 weeks (68.0 ± 3.79), 12 weeks (74.8 ± 2.95), and 6 months (80.0 ± 2.78). All observed changes were statistically significant (P < 0.001). As indicated in Table 3, the postoperative Visual Analog Scale for Functional Assessment (VAS-FA) at 12 weeks (β = 13.6036, P = 0.047) serves as a significant predictor of recovery. This finding underscores the importance of pain management and functional improvement at 12 weeks post-surgery as strong indicators of long-term recovery following tendon graft harvesting. The duration of the injury, particularly when exceeding 16 months (β = −15.2463, P = 0.015), significantly influences the outcome, with longer injury durations associated with poorer recovery. This suggests that the chronicity of the injury may adversely affect the healing process and overall recovery. Conversely, preoperative pain (VAS-FA) (β = −2.9075, P = 0.318) and preoperative function (AOFAS) (β = −0.1217, P = 0.794) were not identified as significant predictors, indicating that early assessments of pain and function may have less impact on recovery compared to later postoperative evaluations. In addition, gender (β = 0.9228, P = 0.746), time to full weight-bearing (β = −2.6802–4.9904, P = 0.892–0.778), and graft size (β = 2.6901–5.8218, P = 0.590–0.226) were also found to be non-significant predictors, suggesting that these factors do not substantially affect the recovery process following ACL reconstruction utilizing PLT graft harvesting.

Our study included participants with a mean age of 36.8 years and an average injury duration of 13.3 months. Full weight-bearing was achieved in 6.43 weeks, with a mean graft size of 8.34 mm. Donor-site morbidity was reported by 66.1% of participants, primarily as mild pain and swelling. Postoperative improvements in VAS-FA and AOFAS scores indicated reduced discomfort and functional limitations. The VAS-FA at 12 weeks strongly predicted recovery, while chronic injuries (over 16 months) negatively affected outcomes. Gender, weight-bearing duration, and graft size were not significant recovery predictors. A study on donor site morbidity after harvesting the PLT for ACL reconstruction found reduced postoperative ankle range of motion compared to preoperative levels and the contralateral side, but no significant impact on ankle strength or functional outcomes, indicating minimal donor-site morbidity ^[14]. Another study showed that PLT grafts had a larger diameter and shorter harvesting time than HT grafts, with patients returning to sports earlier and reporting better knee outcomes at 6 months. However, there were no significant differences in graft rupture or long-term outcomes at 24 months, suggesting PLT supports early recovery without compromising long-term success ^[15]. A long-term study on HT grafts indicated good clinical stability and low failure rates at a median follow-up of 21 years, but nearly half of the patients showed radiographic signs of osteoarthritis, particularly those with meniscectomy ^[16]. Research on postural control after ACL reconstruction with PLT showed significant improvements in balance 6 months post-surgery, concluding that PLT grafts do not negatively affect postural control ^[17]. A randomized study by Dwidmuthe et al. ^[18] found that PLT grafts had longer lengths and shorter surgery times than HT grafts, with similar functional outcomes. PLT grafts had fewer donor-site complications, while HT grafts had more muscle atrophy and sensory changes. Acharya et al. ^[19] found that while the PLT group had a larger graft diameter and fewer complications, the HT group experienced more persistent thigh pain and paraesthesia, suggesting PLT may offer advantages in donor site complications, though tailored rehabilitation is necessary for optimal recovery. Rajani et al. ^[20] found that peroneus longus autograft used in ACL reconstruction resulted in excellent functional outcomes and clinical stability, with 90.27% of patients showing no laxity, a mean foot and ankle disability index of 94.8, and good graft uptake on magnetic resonance imaging after 3 years, with minimal donor site morbidity. However, this study has several limitations. Follow-up period in this study was limited to 6 months. Although early functional recovery was well documented, potential late complications such as residual weakness, ankle instability, or degenerative changes could not be assessed. Longer-term follow-up studies are warranted to fully evaluate the durability of functional outcomes and donor site morbidity. The absence of a comparator group, such as patients undergoing ACL reconstruction with hamstring or patellar tendon autografts, restricts the ability to directly compare donor site morbidity and graft efficacy. Future randomized controlled studies comparing PLT grafts with other autograft options would strengthen the comparative evidence. No objective measurements of ankle strength (such as isokinetic dynamometry) were employed. Objective biomechanical assessments would have provided a more precise evaluation of functional impairments following PLT harvesting.

Our study highlights that harvesting the PLT for ACL reconstruction results in minimal donor site morbidity, with 66.1% of participants reporting mild pain and swelling that significantly improved over time. Functional assessments using the VAS-FA and AOFAS scores showed considerable recovery by 12 weeks, with continued improvement at 6 months. Factors such as preoperative pain and function were not significant predictors of recovery, but chronic injuries (lasting more than 16 months) negatively affected outcomes. Gender, time to full weight-bearing, and graft size also had no significant impact on recovery. These findings suggest that PLT grafts provide a promising alternative to traditional autografts for ACL reconstruction, offering comparable functional outcomes while reducing donor site complications. Further research with larger sample sizes and longer follow-up is needed to confirm these results and assess long-term outcomes, but overall, PLT harvesting is an effective and viable option for ACL reconstruction with minimal impact on donor ankle function and recovery.

PLT grafts offer a reliable and safe alternative for ACL reconstruction, with minimal donor site morbidity. Although mild ankle pain and swelling are common early postoperative complications, they tend to resolve significantly by 6 months, without affecting functional outcomes. PLT harvesting can be considered a viable autograft option, particularly in patients requiring larger grafts or those undergoing revision ACL surgery.