A prospective study to evaluate the functional and clinical outcome of anterior cruciate ligament reconstruction with standard hamstring autograft

Abstract

Background: 

The anterior cruciate ligament (ACL) is the primary stabilizer of the knee and prevents the knee against anterior translation. It is also important in counteracting rotational and valgus stress. The arthroscopically aided approach has the advantages of smaller skin and capsular incisions, improved viewing of the intercondylar notch for placement of the tunnel and attachment sites, less postoperative pain, fewer adhesions, earlier motion, and easier rehabilitation. The advantages with semitendinosus grafts are the availability of a greater sectional area and the unaffected integrity of the extensor mechanism. Moreover, the tensile strength of quadrupled hamstring is found to be even better than a normal ACL. The rate of complications such as extension loss, anterior knee pain, and surgical site infections was also lower than in other procedures such as in BPTB grafts. Cortical suspension devices have the necessary biomechanical properties with regard to ultimate failure strength, displacement, and stiffness for the initial fixation of soft tissue in the femoral tunnel for ACL reconstruction. The aperture fixation methods such as the interference screws allow for early firm fixation and heal with a tight bone–tendon interface.

Objective: 

A prospective study to evaluate the functional and clinical outcome of ACL reconstruction with standard hamstring autograft.

Materials and Methods: 

The study results included 30 patients admitted with clinical and radiological deficiency of ACL from September 2019 to March 2021 using endobutton and bioabsorbable interference screw in terms of range of motion, postoperative knee stability, subjective knee functions, and prospective assessment of functional outcome using Tegner Lysholm knee scoring system.

Results: 

Sports injuries were the most common mode of injury (n = 17, 56.7%). The mean size of graft used was 8.2 ± 0.39 mm. Postoperatively at 2-year follow-up, 30 cases (100%) had 0 grade pivot-shift test, 0 grade Lachman test, and anterior drawer test. The mean postoperative Lysholm score improved from preoperative score of 62.83 ± 5.2–91.0 ± 5.54. The overall satisfactory result (excellent + good) at 6-month follow-up was (excellent – 30 and good – 70) 100%. Out of this, 27 (90%) patients had returned to preinjury level of activity in 1 year. In this study, one patient had superficial infection and two patients had knee pain.

Conclusion: 

Arthroscopy-assisted ACL reconstruction using hamstring tendon autograft provides a stable knee, reduces postoperative morbidity, and enables early rehabilitation.

INTRODUCTION

The anterior cruciate ligament (ACL) is the primary stabilizer of the knee and prevents the knee against anterior translation. It is also important in counteracting rotational and valgus stress.[¹] ACL rupture is the most common serious injury of the knee.[²] ACL reconstruction is an established and widely practiced surgical procedure with proven efficacy and a low morbidity profile.[³] ACL reconstruction with soft parts (hamstring autograft) is a method more frequently used nowadays.[⁴] Moreover, the tensile strength of quadrupled hamstring is found to be even better than a normal ACL.[⁵]

MATERIALS AND METHODS

The study was conducted on 50 patients admitted with clinical and radiological deficiency of ACL from September 2019 to March 2021, in the Department of Orthopedics, Indira Gandhi Institute of Medical Sciences, Patna. Twenty patients were excluded from the study. The study results included 30 patients with minimum of 6-month follow-up.

Inclusion criteria:

1. Age between 18 and 40 years with isolated ACL tear
2. Standard arthroscopic ACLR using hamstring tendon autograft
3. Suspensory fixation on the femoral side by both fixed and adjustable loops was included in the study.

Exclusion criteria:

1. Associated injuries with ACLR (menisci/collaterals injury)
2. Allograft, bone–patellar tendon graft, quadriceps tendon, or synthetic grafts
3. Nonarthroscopic ACLR
4. Previous injured knee and arthritic knee
5. Patient not giving consent
6. Septic knee
7. Congenital deformity of knee.

Clinical assessment

On admission of the patient, a careful history was taken from the patient to reveal the mechanism of injury and the severity of the trauma. The patients were then evaluated clinically for laxity by Lachman, ant drawer, and pivot-shift test in an operation theater under spinal anesthesia and assessed by the Lysholm Tegner knee scoring system [Table 1].[⁶]

Table 1: Lysholm Tegner knee score at 6^th-month follow-up

Radiographic assessment

Standard guidelines were followed to get radiographs. AP and Lateral Xray of affected knee. All the patients were also evaluated by MRI of knee preoperatively.

Preoperative evaluation

All the patients were explained the aims of the study and the methods involved and informed written consent was obtained before being included in the study. All patients with clinical and radiological deficiency of ACL were initially evaluated with diagnostic arthroscopy of knee. Patients meeting the inclusion and exclusion criteria were selected for the study.

Operative procedure

Supine position under spinal anesthesia was an operative procedure.

Diagnostic arthroscopy

Before the harvesting of graft, diagnostic arthroscopy is done to assess suprapatellar pouch, patellofemoral joint, medial gutter, medial meniscus, intercondylar notch, lateral meniscus, lateral gutter, and posterolateral compartment.

Hamstring graft harvest and graft preparation

A 3-cm oblique skin incision is made starting 5 cm below the medial joint line and 1 cm medial to the tibial tuberosity.

The superior border of the pes anserinus is identified using the fingers. This superior border is lifted and fascia incised. The tendons can be felt with fingers running from above downwards. The lowest one felt is the semitendinosus tendon. With the help of right-angled artery forceps, the gracilis and then the semitendinosus are hooked out and further taken out with help of tendon stripper.

The harvested graft is then placed on Graft Master Board. The tendons are removed of any residual muscle fibers with the help of blunt end of the blade.

A whipstitch is placed at both ends of the tendons. Around 3–4 cm of both ends of the tendon were stitched together. The composite graft is then passed through the graft sizer to measure the diameter at the femoral and tibial end.

Intra-articular preparation

The arthroscope was introduced through the anterolateral portal and the joint cavity was visualized. The shaver blade is inserted through the anteromedial portal and the joint is debrided of ligamentum plicae, fat pads, and synovial reflections.

Femoral tunnel preparation

The ACL footprint is visualized on the medial surface of the lateral femoral condyle in 90° of knee flexion and the entry point is marked. Then, with the femoral offset aimer device inserted through the anteromedial port, the entry point is drilled with a guidewire in 120° of knee flexion. The drilling is continued till the tip of the guidewire emerges on the lateral side of the distal thigh at the level of the epicondyle of the femur.

Then, using the 4.5-mm cannulated drill bit, the femoral tunnel was made by drilling both the near and far cortices. Then, the length of the tunnel is measured using a depth gauge. Then, the femoral tunnel is reamed with a reamer corresponding to the diameter of the graft. The reaming stopped 15–20 mm from the lateral cortex depending on the length of the graft. After the femoral tunnel is made, the beath pin with ethibond at its end is passed through the femoral tunnel to aid in easy passage of the prepared graft.

Tibial tunnel preparation

The tibial tunnel is made with the help of the tibial guide. With the knee in 70°–90° of knee flexion, the tip of the tibial guide is placed 2–3 mm anterior to the (posterior margin of) anterior horn of lateral meniscus and slightly medial to the midline of the ACL tibial attachment area. Then, the tibial tunnel is made by reaming over the guide pin using cannulated drill bit with diameter equal to the diameter of the graft.

Graft preparation, passage, and fixation

After the graft had been prepared, based on the length, the graft is quadrupled, the loop part of the quadrupled graft is attached to the endobutton with loop (the length of the loop in the endobutton depends on the graft length and the length of the unreamed femoral tunnel). The ethibond suture already presents within the joint is pulled out through the tibial tunnel. Then, the passing sutures for the ACL graft are passed through the suture loop and are taken out of the lateral thigh. With the help of these sutures, the graft is pulled through the tibial tunnel into the joint and then into the femoral tunnel. Once the estimated length of the graft is within the tunnel, the endobutton is flipped.

Then, cyclical tensioning of the graft is done by repeated knee flexion and extension (around 20–30 times) with sustained pull on the graft through the tibial tunnel. Then, the arthroscopic visualization of the graft is done to look for any signs of graft impingement, alignment, etc. The tibial side of the graft is fixed with an interference screw (titanium or bioscrew) of appropriate length.

The ports and the graft harvest site wound are closed in layers. Sterile compressive dressing is then applied. The limb is immobilized with the use of knee brace.

Postoperative period

Immediate postoperative complications such as postoperative swelling, compartment syndrome, neurological damage, and vascular injury are looked for. Patients were hospitalized for 5 days postoperatively.

RESULTS

Age distribution

Most of the patients (46%) were in the age group of 18–25 years, mean age of 24.5 ± 3.3 years, followed by 26% in the age group of 36–40 years and (14%) each in group 26–30 years and 31–35 years.

Side of injury

In this study, the right and left sides were equally involved.

Duration from injury to surgery

In this study, maximum of patient 13 (43%) got operated within 3 months of injury mean time 3 ± 0.5 months, within 4–6 months 10 patients (33%).

Mode of injury

The most common mode of injury in our study was sports injury 17 (56.7%) and road traffic accident (RTA) (7) (23.3%%), followed by others 6 (20%).

Presenting symptoms

In the study, the most common symptom at presentation was knee instability (88% of patients). The other presenting symptoms were pain (60%) and locking (15%), and the mean time of presentation to the hospital after injury was 36 ± 4.9 days.

Graft size

The graft size used consisted of grafts of 7 mm, 8 mm, and 9 mm. 8-mm graft was used in the majority (73.3%) of the patients, followed by 9 mm (6.6%) and 7 mm (20%) grafts. The mean size of the graft was 8.2 ± 0.39 mm.

Postoperative knee flexion (6 months postoperative)

In this study at 6-month follow-up, 22 (73.3%) patients achieved knee flexion from 0 to 140°, 06 (20%) patients achieved knee flexion from 0 to 130°, and 02 (6,6%) patients had knee flexion of <130°.

Manual laxity tests

Anterior drawer test

Preoperative grade 1 was 2 (6.6%), grade 2 4 (13.3%), and grade 3 24 (80%), and on 6-month follow-up, all 30 patients had grade 0 anterior drawertest.

Lachman test

Preoperative grade 2 was 4 (13.3%) patients and grade 3 was found in 26 (86.6%) patients. All 30 patients had grade 0 at 6-month follow-up.

Pivot-shift test

Preoperative 2 (6.6%) patients had grade 2 and 28 (93.3%) patients had grade 3, while at 6-month follow-up, 30 patients had grade 0 test.

Complications

In this study, one patient had superficial infection, two patients had knee pain, and zero patients had sense of giving away during exertional activities. Clinical images: [Figures 1 and 2] depicts preoperative and postoperative findings.

Figure 1: 23-year male with right ACL tear: (a) Preoperative MRI showing torn ACL, (b) On final F/U no extensor lag in knee, (c) Postoperative knee X-ray showing endobutton femoral fixation and bioscrew tibial side fixation, (d) patient ability to squat without much difficulty on final F/U. ACL: Anterior cruciate ligament, MRI: Magnetic resonance imaging

Figure 2: 40-year female with left ACL tear: (a) Preoperative knee MRI showing torn ACL, (b-d) showing complete range of painless knee movement ability to squat without much difficulty, no extensor lagar final F/U, (e) postoperative knee X-ray depicting endobutton femoral fixation and bioscrew tibial fixation. ACL: Anterior cruciate ligament, MRI: Magnetic resonance imaging

DISCUSSION

The primary goal of ACL reconstruction is to restore the stability of the knee. Successful clinical outcomes following ACL reconstruction with a semitendinosus graft have been reported by many authors.[⁶] The choice of fixation in ACL reconstruction is still evolving and the current fixation device which has been widely used is the endobutton and the biocomposite interference screws which has helped to render an improved rehabilitation program postoperatively.[⁷] All patients in our study underwent arthroscopy-assisted ACL reconstruction with double bundle quadrupled hamstring tendon autograft from ipsilateral limb using endobutton (Smith and Nephew), cortical suspensary fixation method for femoral side and bioabsorbable interference screw (Smith and Nephew), and aperture fixation method for tibial side.

Age distribution

The mean age of patients (in years) in our study was 24.2. The results of our study are comparable to the results of other studies [Table 2].

Table 2: Comparative analysis of variables and outcome of different studies with the present study

Side of injury

Brown et al.[¹³] studied the incidence of the sidedness of limb injury and sex incidence and stated that although their study pointed out that females are more prone to this injury, the incidence is yet, more in males due their increased exposure to work in a strenuous environment. They also hypothesized that limb-sidedness has no influence either during injury or the recovery period. In our study, 50% of patients had injuries on the right side and 50% of patients had injury on the left side [Table 3].

Table 3: Comparative analysis of side involvement with the present study

Mode of injury

Chaudhary et al.[¹⁰] in their study noted that injury caused by sporting activities accounted for 66.7% of the patients, whereas motor vehicle accident and household injuries accounted for 30.8% and 2.5%, respectively. Studies conducted by Patond et al.[¹⁴] found sports activities to be the predominant cause of ACL injuries. However, in another study, Subhash et al.[¹⁵] found motor vehicle accidents accounted similar incidence of ACL injury as sports activity. In our study, the most common mode of injury was sports (56.7%), followed by RTA (23.3%) and then others (20%) injuries.

CONCLUSION

From this study, it can be concluded that arthroscopy-assisted ACL reconstruction using hamstring autograft provides a stable knee, reduces postoperative morbidity, and enables early rehabilitation. The functional outcome is excellent to good and allows the patients to return to preinjury level of activity, allows the patient to squat, sit with crossed legs, and climb stairs without difficulty.

Limitation of the study

The limitation of the study was short period of follow-up and small sample size.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.