The anterior cruciate ligament (ACL) is well known for its primary restraint on the anterior translation of tibia on femur. It also prevents hyperextension of knee during full extension. It is a secondary stabilizer of the knee against rotational and varus and valgus stress. The ACL injury is one of the most common serious ligament injuries of the knee due to its primary role in knee stabilization and its role in knee biomechanics ^[1]. The ACL rupture being the one of the most common cause for visit to the orthopedic clinic and its reconstruction is strongly recommended for an active patient as it prevents any knee instability, further knee injuries, meniscal damage, and early osteoarthritis ^[2]. The arthroscopic approach has advantages such as smaller skin and capsular incisions, improved viewing of the intercondylar notch for placement of tunnel and attachment sites, fewer adhesions, lesser postoperative pain, early motion, and easier rehabilitation ^[3]. ACL injuries are more common among active young people where road traffic accident (RTA) and sports injuries predominate as the most common methods of injury ACL reconstruction with peroneus longus graft method have used more frequently nowadays. (Fig. 1). The advantages of peroneus longus graft are as follows:

• Adequate graft length of minimum of 25–30 cm
• Adequate thickness of minimum 8.5–9 mm
• Less incidence of graft thinning
• Lesser hamstring and quadriceps weakness.

• Minimal donor site morbidity
• Minimal restriction of ankle movements

The current gold-standard treatment for ACL tear is arthroscopic reconstruction, and the most commonly used autografts for primary ACL reconstruction are bone-patellar tendon-bone and four-strand hamstring tendon graft.

A prospective study of 25 patients with injured ACL without meniscal injury within the age group of 18–55 years managed with arthroscopic reconstruction of ACL with peroneus longus graft and fixed loop endobutton at femoral side and interference screw at tibial side. Sample size was calculated using Cochran’s sample size formula.

Inclusion criteria

1.   Age 15–55 years

2.   ACL injury with or without meniscal injury

3.   Associated with symptoms of instability.

Exclusion criteria

1. ACL avulsion fractures and multiligament injuries
2. Fractures in the ipsilateral or contralateral limb

3. Revision ACL surgery

Functional outcome was assessed using clinical examination, international knee documentation committee, Lysholm knee scoring scale, and foot and ankle disability index score (FADI score). Patients were followed up at 2, 4, 8, 12 weeks and 6, 8 months post-operatively.

Maneuver

All surgeries were done with a pneumatic tourniquet. Surgeries were performed in supine position with the operating knee flexed to 60–70° with the help of a bolster and a thigh support with standard anteromedial and anterolateral portals. Diagnostic arthroscopy was done to assess the internal derangement of the knee and confirm an ACL tear. Peroneus longus was harvested using a 5 cm vertical incision placed proximal to lateral malleolus. Graft was doubled and prepared on the graft master board. Average thickness of the graft was measured to be 8.1 ± 0.7–0.9 mm and average length of the graft was measured to be 22 cm. (Fig. 2). Femoral and tibial tunnel was prepared using appropriate size drills and instruments. Prepared graft was mounted on a fixed-loop endobutton and fixed to the femoral side. Tibial side was secured using an interference screw. Post-operative physiotherapy was followed as per standard ACL rehabilitation protocol. (Fig. 3).

Successful clinical outcomes following ACL reconstruction with a peroneus longus graft has been reported by many authors with the primary goal of ACL reconstruction being restoring the stability of the knee [4-9]. All patients in our study underwent arthroscopy-assisted ACL reconstruction with doubled peroneus longus autograft from ipsilateral limb using fixed-loop endobutton, cortical suspensary fixation method for femoral side and non-absorbable titanium interference screw, and aperture fixation method for tibial side. [10-14]. (Fig. 4 and 5).

Mode of injury

A study conducted by Chaudhary et al. ^[13] opined that 66.7% injuries were caused by sporting activities, followed by motor vehicle accident accounted for 30.8%. Another study conducted by Patond et al. found sports activities to be the predominant cause of ACL injuries. In our study, 15 (60%) participants had sports related injuries, 7 (28.34%) were due to RTAs, and 3 (12%) were other modes of injury such as skid and fall and atraumatic degenerations suggesting comparable modes of injuries.

Age distribution

The mean age of patients (in years) in our study was 28.48 ± 6.65 years. The results of our study are comparable to the results of other studies such as the ones conducted by Chaudhary et al. ^[13] (mean age of 26.8 years) and Specchiulli et al. ^[12] (mean age of 27 years).

Functional outcome

The mean post-operative FADI score showed no change in pre-operative score of 99.6–98.6% in our study. The mean post-operative IKDC score improved from pre-operative score of 64–99% in our study. In Cirstoiu et al., there was early recovery with minimum post-interventional pain, increased mobility of the knee as early as 1^st 2-week post-operation, and significant reduction of duration of hospitalization and costs when arthroscopic ACL reconstruction was performed with peroneus longus autografts. In Rhatomy et al., ACL reconstruction with peroneus longus autograft has excellent functional score in IKDC, modified Cincinnati, Tegner–Lysholm score at 2-year follow-up with the advantages of greater graft diameter, less thigh hypotrophy, good serial hop test result, and excellent ankle function based on AOFAS and FADI score.

Limitations of the study

It is not a comparative study done with hamstring graft.

This study consists of 25 cases of ACL injury. ACL rupture was common in second and third decade of life. In our study, 18 (63.34%) were sports-related injuries, 5 (26.66%) were due to RTAs, and 2 (10%) were atraumatic degenerations. 22 (80%) showed excellent results and 3 (20%) showed good results. As per the IKDC scores, the post-operative average of 95.6 ± 5.277% was found to have a P < 0.05 compared to pre-operative average of 46.4 ± 10.612 making it statistically significant. As per the Lysholm scores, 23 patients (80%) had excellent results whereas 2 patients (20%) had good results. As per the FADI, the post-operative average of 98.6 ± 2.277% was found to have change in P-value compared to pre-operative average of 99.6 ± 8.712 making it statistically insignificant.

Arthroscopic ACL reconstruction using peroneus longus graft and fixed-loop endobutton and interference screws provided excellent post-operative clinical outcome in terms of knee stability, subjective knee and ankle function, and range of movements of the knee and ankle in our study.

Improvement in the functional outcome noted related to the graft and implant peroneus longus graft has an advantage in terms of adequate graft thickness and length compared to the other autografts.