Surgical technique

A lateral position and posterior lateral approach were used for THA. While a supine position and patellar medial approach were used for TKA. For a certain patient, the same type of prosthesis was used for both sides, and the incisions on the 2 sides were closed by the same 2 assistants. Both assistants had experience using barbed sutures in at least 50 cases. Four layers needed to be closed for each patient, including the fascia (hip)/joint capsular(knee), fat, subcutaneous and skin. Wound closure of the knee was performed with the patient in a 30° flexion position.

For the barbed group, we used running knotless #2 Quill for the fascia (hip)/joint capsular (knee). After finishing this layer, we did not cut the suture; on the contrary, we made a “U turn”, suturing back towards the middle of the deep fat layer (Figure 2). After reaching the middle of the deep fat layer, we cut the suture and then used #2-0 Vicryl for 2 or 3 interrupted sutures. If the length of the #2 Quill was insufficient, more interrupted #2-0 Vicryl was used to fill up the blank. Interrupted suturing (#2-0 Vicryl) was performed in the subcutaneous layer, and we sutured this layer combined with the superficial fat layer (approximately 0.5 cm). Finally, we used skin staples (Table 1).

Suturing method for the barbed group. (A) We used running knotless #2 Quill for the fascia (hip)/joint capsular(knee) from the center to the sides. (B) After finishing the final layer, we did not cut the suture; on the contrary, we made a “U turn”, suturing back towards the middle of the deep fat layer. (C) After reaching the middle of the deep fat layer, we cut the suture and then used #2-0 Vicryl for 2 or 3 interrupted sutures. (D) Ready to use staples after performing interrupted suturing (#2-0 Vicryl) in the subcutaneous layer.

Suturing strategy.

For the control group, we used the traditional method, #1 Vicryl for successive chain-shaped suturing in the fascia (hip)/joint capsular(knee). We used #2-0 Vicryl for inverted interrupted suturing in the fat and subcutaneous layers. Then, staples were used for the skin (Table 1).