Analysis of Standard Versus Barbed Sutures in Primary Total Knee Arthroplasty.

Knotted suture have traditionally been used for surgical closures. The technique of closing a surgical incision with sutures tied with knots has been the standard for wound closure without any other alternative until recently. Knotted suture technique is a reliable and safe method for wound closure. However, knotted sutures do present several possible disadvantages. Knots take a long time to tie and may place difficult demands on tissue. The bulk of knots may cause tissue inflammation during the process of being absorbed and possibly an area for infection as well as a chance for scaring. Knotted sutures can push out through skin weeks after surgery allowing a site of incision infection. Also, repetitive needle handling during knot tying puts the surgeon at inherent risk.

Barbed sutures are self-anchoring and require no knots for wound closure. The lack of knots may provide several benefits. After surgery tissue strain may be decreased, potentially lowering the risk of reduced blood supply to local tissue. The absence of knots may lead to decreased skin irritation and superficial infections as the knots do not need to be absorbed. Additionally, speed of closure might be better with knot-less suture, allowing increased operative day efficiency and productivity. On the other hand, barbed sutures may have disadvantages. Suture pullout and breakage are both possible causes of suture failure with potentially more consequence due to lack of interrupted suture technique. In theory, if the barbed suture breaks near the midpoint, the angled barbs could allow pullout and wound breakdown. In a recent large review of total joint wound closures, barbed sutures were found to be safe. They have been used in a large number of patients for the past few years here at our center as well as many other centers without significant complications. Of note, all surgeons participating in this study have successfully used both of the above mentioned closure techniques for their patients in the recent past.

Reducing postoperative wound complications and improving cosmetic outcomes are important reasons to optimize multilayered closure in a median parapatellar approach to total knee arthroplasty. With decreasing reimbursement and rapidly increasing surgical demand, closure time may be one of the largest targets to reduce operative time and cost while increasing operative productivity.1, 2 Running knotless suture technique utilizing barbed suture technology has been described to facilitate closure and repair of soft-tissues in the plastic-surgery literature.3, 8 Prior studies have looked at use in tendinous repairs of flexor tendons with encouraging results.5, 7 While the plastics literature has reported favorable efficiency and clinical outcomes for dermal closure3, and separately, plication of abdominoplasty flaps to the underlying abdominal wall8, no studies have reported on the use of barbed suture for multi-layered closures.

While knotted suture have traditionally been used for surgical closures they present several potential disadvantages3. Knots are tedious to tie and may place ischemic demands on tissue. Bulky knots may cause location tissue inflammation during the process of being absorbed and therefore be a nidus for infection and create an environment for increased scaring. Occasionally, sutures extrude through skin weeks after surgery allowing a potential pathway for infection. Additionally, needle handling during knot tying predisposes the surgeon to inherent risk.

In contrast, barbed sutures are self-anchoring, requiring no knots for wound closure, which may have several advantages over knotted technique. Tissue tension may also be more optimal, lowering risks for local tissue ischemia and elimination of knot tying may have advantages for the above reasons. Additionally, speed of closure might be better with knot-less suture, enabling increased operative day efficiency and productivity.

With barbed suture there are several potential drawbacks; suture pullout and breakage are both possible causes of suture failure with potentially more dramatic consequences due to lack of interrupted suture technique. Theoretically, if the barbed suture breaks near the midpoint, the unilaterally angled barbs could allow pullout and yield dehiscence.

Several biomechanical studies have evaluated barbed suture in the repair of flexor tendons. Trocchia et. al compared repair of flexor tendons in cadavers using standard suture technique with 3-0 Ethibond to 2-0 Quill.7 Biomechanical testing determined that load to failure significantly favored Ethibond but found no statistical difference with tensile load at 2-mm gapping.

Parikh et al. demonstrated satisfactory strength at failure in barbed suture compared to knotted technique in cadavers with less bunching of the tendons, greater load to failure.5 Additionally, mechanism of failure in the barbed suture group differed from the knotted group as it failed by suture breakage rather than pullout or knot failure.

O'Reilly et al. compared barbed suture to interrupted knotted suture for closure of parapatellar arthrotomies in cadaver knees and found that both methods maintained closure with cyclical loading.4 With sequential cutting of center sutures and repeat cycling, the barbed suture survived significantly more cuts (range 3-7 cuts) before gapping of 2 millimeters occurred compared to the interrupted technique (1-3 cuts).

Several studies have evaluated barbed suture in wound closure. Warner et. al evaluated use of barbed suture technique in abdominoplasty surgery to plicate the flap to the underlying abdominal fascia via progressive tension closure.8 Barbed suture was found to markedly reduce closure times and was not associated with any increase in complications compared to the standard suture technique.

Murtha et al. performed a prospective, randomized, controlled trial evaluating the use of barbed suture in dermal closure of the Pfannenstiel incisions after elective caesarian delivery.3 At 5 wks in 188 women there was no difference in cosmesis scores, adverse events, closure time, and pain scores between the groups.

No studies have yet reported on the use of barbed suture for closure in orthopaedics. We have recently performed a retrospective case controlled study to determine if there were differences in clinical outcome and cost when comparing barbed suture to standard knotted suture in layered closure in primary total knee arthroplasty (TKA). From this study, currently in submission for publication, we found that use of barbed suture is associated with significantly shorter closure times and similar overall cost for closure, with no difference in postoperative complications in primary TKA. Based on our data from nearly 200 patients, we feel that layered closure with barbed suture in total knee arthroplasty is a safe technique. A multicenter prospective randomized study comparing standard closure to barbed suture closure in primary total knee arthroplasty would provide a necessary answer to clinical questions in terms of outcomes and cost of this new technique compared to more traditional knotted suture closure.

The study and control groups will be made up of consecutive patients undergoing a median parapatellar approach primary total knee arthroplasty at the University of Utah Hospital and Clinics,The control group will undergo two-layer closure utilizing a standard interrupted, knotted suture technique. The closures will be performed by 2 members of the team (attending surgeon, resident, fellow, or PA) in ALL closures so as to limit the possible confounder of closure time variation due to different numbers of people closing the incision. This will specifically consist of arthrotomy closure using interrupted #1 Ethibond™ in figure of eight fashion and sudermal closure using 2-0 Monocryl™ in interrupted buried fashion.

• Barbed sutures
  barbed sutures are self-anchoring, requiring no knots for wound closure, which may have several advantages over knotted technique.
• knotted sutures
  Knotted sutures used for traditional surgical closures.

Inclusion Criteria:

• Inclusion Criteria:
• Patients greater than 18 years of age diagnosed with arthritis of the knee that have elected to proceed with primary total knee arthroplasty respectively.

Exclusion Criteria:

• - Patients less than 18 years of age
• Prior open knee surgery in close proximity (<2cm) to the proposed incision for the primary total knee arthroplasty (prior arthroscopic surgery does not exclude a patient from the study)
• Wound or Scar in close proximity (<2cm) to the proposed incision for the primary total knee arthroplasty