Acute hemarthrosis: a histological, biochemical, and biomechanical correlation of early effects on the anterior cruciate ligament in a rabbit model

Intra-articular Administration of Tranexamic Acid Has No Effect in Reducing Intra-articular Hemarthrosis and Postoperative Pain After Primary ACL Reconstruction Using a Quadruple Hamstring Graft: A Randomized Controlled Trial

Background:

Insufficient data are available to support the routine use of tranexamic acid (TXA) in anterior cruciate ligament (ACL) surgeries with respect to administration method and frequency, exposure duration, dose, and adverse effects.

Purpose:

To investigate whether intra-articular (IA) administration of TXA could reduce hemarthrosis and postoperative pain in patients after ACL reconstruction.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 47 patients were included in this study, which was performed between July 2017 and May 2019. Single-bundle reconstructions using autologous hamstring tendon grafts were performed in all patients. The patients were randomized into 2 groups: the TXA group (received the index procedure with 100-mL IA injection of TXA [30 mg/mL]) and a control group (did not receive IA injection of TXA). No patients received a drain. Blood loss was calculated on the basis of hemoglobin balance at postoperative day (PD) 2. The visual analog scale (VAS) for pain score was assessed at PD 3. The midpatellar circumference was measured at PD 2 and PD 5. Knee range of motion (ROM) was evaluated 6 weeks after surgery.

Results:

The mean ± SD blood loss was 467 ± 242 mL in the TXA group and 558 ± 236 mL in the control group. No significant differences were found for blood loss (P = .20), VAS pain scores (P = .28), ROM at postoperative week 6 (P = .61), or patellar circumference at PD 2 (P = .75) and PD 5 (P = .84).

Conclusion:

This study showed that IA administration of 3.0 g of TXA had no effect in reducing blood loss and postoperative pain after primary anatomic single-bundle ACL reconstruction using quadruple hamstring autografts.

Registration:

NCT04042688 (ClinicalTrials.gov identifier).

Biotribological and biomechanical changes after experimental haemarthrosis in the rabbit knee

Changes in articular cartilage after haemarthrosis have not been completely elucidated in haemophilic arthropathy. Insights into the pathophysiological mechanisms of blood-induced joint damage mainly derived from histological, inflammatory and biochemical investigations. A structure-function relationship is another reasonable way to determine the joint overall health status. Cartilage, a viscoelastic connective tissue, is at least a biphasic material that should also work under minimal friction. Pendulum friction tester measures the mechanical aspects of joint lubrication and quantifies the biotribological properties of the joint. Indentation test is an in situ method characterizing the biomechanical properties of the cartilage. Gross, biotribological and biomechanical properties were determined in a rabbit model of experimental haemarthrosis. A sample of 1 mL of fresh autologous blood was injected in the left knee of rabbit's joint twice weekly for four consecutive weeks. The right knee and animals in the control group were left untreated. After 8 days, joint perimeter, biotribological and biomechanical tests were performed. In a consistent manner, all data showed detrimental effects of the blood on the overall cartilage function under loading. Non-weight bearing and early blood aspiration seem wise to be considered after haemarthrosis.

Bleeding from the bone marrow enhances remodeling of the in situ frozen-thawed anterior cruciate ligament

BACKGROUND

The purpose of this study is to biomechanically and histologically evaluate the effect of bleeding from bone marrow on remodeling of the in situ frozen-thawed anterior cruciate ligament.

METHODS

Forty-four rabbits were used. Eight rabbits were used to evaluate the amount of bleeding at days 1-4. Thirty-six rabbits were divided into two groups, after the right anterior cruciate ligament underwent the freeze-thaw treatment. In Group I, no treatments were applied. In Group II, a tunnel was drilled into the bone marrow the femoral intercondylar notch. Each rabbit was sacrificed at 6 or 12 weeks. We examined the mechanical properties, and the histology of the anterior cruciate ligament.

FINDINGS

A small amount of blood clot was observed only on the first day in Group I, while a large amount of blood clot was seen around the anterior cruciate ligament for 3 days after surgery in Group II. In the midsubstance, a number of cells were scattered in Group II, no cells were seen in Group I at 6 weeks. The tangent modulus showed some tendency of difference between Groups I and II at each period.

INTERPRETATION

Bleeding from the bone marrow obviously enhanced extrinsic cell infiltration into the in situ frozen-thawed anterior cruciate ligament at 6 weeks, and showed some effects on its mechanical properties. This study implied that, in anterior cruciate ligament reconstruction, the blood from a bone tunnel play an important role in graft remodeling.

Mechanical properties of the anterior cruciate ligament chronically relaxed by elevation of the tibial insertion

The effects of stress deprivation on the mechanical properties of the anterior cruciate ligament were studied in a canine model. Fifty-eight mature mongrel dogs were divided into two groups. In the relaxed group (n = 30), the tibial insertion of the anterior cruciate ligament in each right knee was surgically elevated proximally 3 mm from the tibia; the elevation was anatomically reduced in the sham group (n = 28). In order to obtain control data, the left knee in each dog was left untreated. A femur-anterior cruciate ligament-tibia complex was excised from each knee for biomechanical tests at 6 or 12 weeks after surgery. To simplify data analysis, the treat/nontreat ratio (the ratio of the data obtained from the treated knee to that from the nontreated knee) was used. The cross-sectional area of the ligament increased significantly in both groups; the area in the relaxed group (average treat/nontreat ratio = 1.37) was significantly larger than that in the sham group (1.16) at 6 weeks but not at 12 weeks. The treat/nontreat ratio of tensile strength in the relaxed group significantly decreased to 0.67 and 0.58 at 6 and 12 weeks, respectively; in the sham group, it significantly decreased to 0.79 at 6 weeks but subsequently increased to 0.87 at 12 weeks. Only at 12 weeks was a significant difference observed between the two groups. This study demonstrated that, in the anterior cruciate ligament, stress deprivation results in a rapid increase in the cross-sectional area, although this effect disappears by 12 weeks, and in a decrease in mechanical strength, although a relatively long period of more than 6 weeks is required for the deterioration.