Clinical outcomes in anterior cruciate ligament reconstruction using peroneus longus tendon autograft versus hamstring tendon autograft

INTRODUCTION

The anterior cruciate ligament (ACL) is one of the knee’s most commonly injured components. ACL injuries lead to enduring and significant impairments due to their vital role in knee function.^[1] Each year, over 200,000 people in the USA suffer ACL tears, which account for more than 50% of all knee injuries.^[2] At present, ACL reconstruction (ACLR) is the most widely accepted and effective approach to restoring knee stability and reducing the likelihood of future meniscal tears and clinical osteoarthritis. This procedure necessitates using one of three options: an allograft, synthetic graft, or autograft.^[3] Several autograft options are currently utilized in ACLR, which include the quadriceps tendon, bone-patellar tendon-bone, and hamstring tendon (HT). These autografts each have positive and negative aspects. Surgeons consider graft strength and dimensions, as well as the ease and safety of graft retrieval, all while minimizing complications at the donor site.^[4,5]

Based on the latest research, bone-patellar tendon-bone stands out as the optimal graft choice due to its bone-to-bone healing, which enables efficient tunnel and graft assimilation, resulting in a faster return to functionality and athletic activity. However, due to the invasive method, defined length, large incision, and weaker than natural ACL, it entails a risk of patellar fracture, which is not suited for the double-bundle reconstruction and has a high incidence of anterior knee discomfort.^[6] A HT autograft has the same strength as a native ACL, and it is easy to take with minor donor site morbidity. Since it has an unknown graft diameter and may cause the loss of hamstring power, it is crucial for certain athletes who need significant hamstring strength^[7] or are affected negatively by other disadvantages such as quadriceps-hamstring imbalance, knee laxity, and various ligament injuries.

Considering the disadvantages of the autografts, an alternative graft material is needed. The peroneus longus tendon (PLT) is of an appropriate size, and biomechanical analysis of its characteristics showed that it has enough strength for knee ACLR.^[8] PLT autografts are frequently employed in several orthopedic procedures, such as repairing the medial patellofemoral ligament, the spring ligament, and the deltoid ligament.^[9] This is feasible due to peroneus brevis and PLT, each having a distinct function. According to some studies, the peroneus brevis is an even more potent ankle evertor, rationalizing the possibility of using PLT as an autograft when needed.^[10]

Only a few comparative studies have been conducted between the PLT autograft and the other grafts. The main purpose of this study was to evaluate the clinical results of patients who had ACLR using HT autograft against patients who had ACLR using PLT autograft.

MATERIALS AND METHODS

This quasi-experimental study was performed at the Orthopedic Department of Pakistan Atomic Energy Commission, General Hospital, Islamabad, from July 2021 to July 2023. Sampling was done using a non-probability consecutive sampling technique. All the available samples during the study duration fulfilling inclusion criteria were included in the study.

RESULTS

Sixty-one patients who underwent ACLR surgery were enrolled in this study; 26 received ACLR using the HT (quadrupled gracilis and semitendinosus), whereas 35 received a PLT. Of the total patients, 55 (90.1%) were male, and 6 (9.9%) were female. The mean age of the patients was 26.51 ± 6.78 years. The HT group had severe pain at six weeks and three months compared to the PLT group (P < 0.05). After six months, patients of both groups had mild pain with P = 0.337. A comparison of the patient’s pain around the knee in the sixth week, third month, and sixth month is shown in Table 1.

There was a statistically significant difference in the ROM between both groups at knee joints at six weeks, three months, and six months, that is, P < 0.05. The comparison of the knee joint ROM (flexion and extension) to a contralateral side at the sixth week, third month, and sixth month is shown in Table 2.

A statistically significant difference was found among the groups in MRC muscle power at the knee joint in the sixth week, third month, and sixth month as P < 0.05 shown in Table 3.

In the sixth month, 21 (80.8%) patients from the HT group and 34 (97.1%) patients from the PLT group could jog without discomfort. After six months, 5 (19.2%) from the HT group and only 1 (2.9%) from the PLT group were able to jog without discomfort (P = 0.034), shown in Table 4.

Furthermore, most patients were satisfied with the treatment; yet, the PLT group patients were more satisfied than the HT group, that is, P = 0.003. The details of patient satisfaction at six months for both groups are shown in Table 5.

DISCUSSION

Knee injuries are often caused by ACL damage, which requires careful reconstruction. Autografts are frequently used because they have a minimal chance of causing negative reactions and zero risk of transmitting diseases. When used as a biological graft, an autograft experiences a process of recollagenation and revascularization, which can result in a 50% loss of strength in the initial stages of implantation.^[14] When considering a replacement for the ACL, choosing a stronger graft substitute than the ACL itself is important. This is due to the native ACL’s maximal tensile load of 2020 ± 264 N.^[15] Over the past few years, the HT has become a popular choice as an autograft for ACLR. However, there is a considerable range in HT diameter, and using a very small graft could increase the risk of failure in ACLR.^[16]

According to previous research, functional outcomes and knee stability have been reported as positive outcomes following ACLR using PLT autograft.^[17,18] In terms of knee function evaluation, the outcomes of ACLR utilizing PLT were considered satisfactory by Angthong et al.^[19] However, clinical examinations conducted at an average follow-up time of 13 months showed that 8.4% of all patients had laxity in the varus talar tilt tests. In addition, 16.7% of patients had grade IV deterioration in eversion and first-ray plantar flexion, and 100% had grade IV+ deterioration in these areas. This study’s American Orthopedic Foot and Ankle Society (AOFAS) Hindfoot Score and the Foot and Ankle Disability Index score shows that the donor’s ankle functioned perfectly after removing the PLT.

Numerous authors have reported positive results of PLT autografts and recommended its use as a substitute for other autografts. Yu et al.^[20] conducted a study involving 35 participants with an average age of 43.4 years. These individuals underwent a procedure where an ipsilateral PLT autograft was administered. Following a 14.2-month follow-up period, it was observed that all patients displayed negative outcomes in the anterior drawer test, Lachman test, and pivot shift test. Evaluating the functional outcome through the Knee Injury and Osteoarthritis Score, International Knee Documents Committee (IKDC), and Lysholm score, a notable improvement (P < 0.05) was observed in the 3^rd, 6^th, and 12^th months in comparison of pre-surgical condition.

According to the study conducted by Kerimoglu et al.,^[17] PLT can serve as a suitable autograft source for ACLR, thereby avoiding potential complications that may arise from autografts obtained from the knee region. Importantly, no patients reported experiencing ankle joint dysfunction or difficulty in sports activities following PLT graft transfer. These results are similar to our study.

Phatama et al.^[21] examined the outcomes of 15 recipients with PLT and 16 individuals with HT. At a 2-year follow-up, the two groups had no significant difference in pain and crepitus. However, according to Phatama et al.^[21] score, the functional outcome was significantly better (P < 0.0001) in the PLT group than in the HT group. These findings are inconsistent with the results of our own study. Cao et al.^[22] demonstrated that PLT autograft was used on 35 patients with a mean age of 31.8 years. After 15 months, the mean Lysholm score was found to be 97.2, with 25 patients having excellent scores. Most patients (88.6%) had outstanding acceptable KT-3000 arthrometer assessments, with a mean AOFAS score of 96.3. Based on the results, the authors recommended PLT as a safe and effective method substitute for ACL without having any donor site morbidity. Kumar et al.^[23] used PLT as an autograft method for ACLR in 25 patients, having a mean graft thickness of 8.74 mm. Post-surgery evaluations showed a mean IKDC score of 98.53 and an MRC grading of 5. Results indicated excellent functional outcomes without adverse effects on ankle stability or movement.

CONCLUSION

According to the study results, patients who underwent ACLR with a PLT autograft had significantly better clinical and functional outcomes than those who received an HT autograft. Therefore, the study suggests that the PLT autograft could be considered an appropriate alternative graft choice outside the knee for patients undergoing ACLR.