Knee arthrotomy closure with barbed suture in flexion versus extension: a porcine study

Comparison of Standard Suture vs Barbed Suture for Closing the Porcine Knee Joint: Evaluation of Biomechanical Integrity and Permeability

BACKGROUND

This study aimed to compare the biomechanical strength and permeability of barbed vs traditional suture for closure of the porcine knee joint.

METHODS

This study used Duroc pig knee joints. For each specimen, a 5-cm medial parapatellar arthrotomy was performed with the knee at 30° of flexion. We closed the arthrotomy wound using barbed suture (size 1/0 V-Loc 180) or traditional suture (size 1/0 PDS II). Specimens were divided into a PDS II (n = 9) and a V-Loc group (n = 9) for biomechanical testing, and a PDS II (n = 9) and a V-Loc group (n = 9) for permeability testing. In biomechanical testing, a continuous load was applied and the wound was pulled apart at 50 mm/min. We compared the maximum load under which each suture type could maintain wound closure. In permeability testing, the knee joints were flexed and extended for 200 cycles at 0.5 Hz from 0° to 120° of flexion. A tube was fixed in the articular cavity of the specimen and connected to a 1.5-m high water capsule. The time taken to wound effusion was compared.

RESULTS

There was no significant difference between the mean load at initial failure for PDS II (424 ± 192 N) vs V-Loc (471 ± 100 N, P = .529), or between the mean time until effusion for PDS II (6.8 ± 3.4 seconds) vs V-Loc (5.5 ± 2.5 seconds, P = .390).

CONCLUSION

Standard and barbed suture had similar wound holding strength and permeability. The barbed suture was as stable as traditional suture.

What are the important surgical factors affecting the wound healing after primary total knee arthroplasty?

Background

Wound condition after primary total knee arthroplasty (TKA) is an important issue to avoid any postoperative adverse events. Our purpose was to investigate and to clarify the important surgical factors affecting wound score after TKA.

Methods

A total of 139 knees in 128 patients (mean 73 years) without severe comorbidity were enrolled in the present study. All primary unilateral or bilateral TKAs were done using the same skin incision line, measured resection technique, and wound closure technique using unidirectional barbed suture. In terms of the wound healing, Hollander Wound Evaluation Score (HWES) was assessed on postoperative day 14. We performed multiple regression analysis using stepwise method to identify the factors affecting HWES. Variables considered in the analysis were age, sex, body mass index (kg/m²), HbA1C (%), femorotibial angle (degrees) on plain radiographs, intraoperative patella eversion during the cutting phase of the femur and the tibia in knee flexion, intraoperative anterior translation of the tibia, patella resurfacing, surgical time (min), tourniquet time (min), length of skin incision (cm), postoperative drainage (ml), patellar height on postoperative lateral radiographs, and HWES. HWES was treated as a dependent variable, and others were as independent variables.

Results

The average HWES was 5.0 ± 0.8 point. According to stepwise forward regression test, patella eversion during the cutting phase of the femur and the tibia in knee flexion and anterior translation of the tibia were entered in this model, while other factors were not entered. Standardized partial regression coefficient was as follows: 0.57 in anterior translation of the tibia and 0.38 in patella eversion.

Conclusions

Fortunately, in the present study using the unidirectional barbed suture, major wound healing problem did not occur. As to the surgical technique, intraoperative patella eversion and anterior translation of the tibia should be avoided for quality cosmesis in primary TKA.