In 2003, more than 400,000 total knee replacements were performed in the United States. This number is expected to increase in the coming decades to 3 million by the year 2030.1 The surgical approach to knee arthroplasty always involves a capsular incision that needs to be repaired after implantation of the components. The capsular incision repair should be strong enough to allow for immediate range of motion.
Traditionally, repair of the arthrotomy is performed using interrupted sutures. Recently, a running technique using barbed suture has been demonstrated to enable faster closure times.2-6 In addition, a running suture technique using barbed suture provides a superior watertight closure compared with an interrupted suture.7 It has been reported that the barbed suture has the same safety profile as that of interrupted sutures,2,3,4 although extensor mechanism repair failure8 and wound complications9,10 have been reported.
This study proposes a novel technique for arthrotomy closure in total knee arthroplasty (TKA). It is a double continuous interlocking stitch, termed the “Flint Lock.” Based on our clinical experience using this method, this technique has been found to be safe and effective.
TECHNIQUE
The Flint Lock was developed for closure in TKA, which was performed through a standard medial parapatellar approach. Before creating the arthrotomy, a horizontal line is drawn along the medial side of the patella to ensure anatomic alignment of the extensor mechanism during closure of the capsule.
The Flint Lock is performed by 2 people working simultaneously. Closure begins at the proximal end of the arthrotomy using 2 No. 1 Vicryl (Ethicon) sutures. Each suture is thrown a single time at the most proximal extent of the arthrotomy with the knee in 30° to 40° of flexion. These sutures are tied off independently from each other (Figure 1). At this point, the knee is flexed to 90° and the sutures are thrown alternately, with the first operator passing medial to lateral through the capsule and the second operator passing lateral to medial. While 1 operator is passing a suture, the other operator holds the other suture tight to maintain tension on the closure. The alternating throws create an interlocking weave as the pattern is repeated and progressively moves distally (Figure 2). This technique results in 2 continuous sutures running in opposing directions. Each No. 1 Vicryl suture is specific to each operator. Therefore, each operator uses the same suture for the entirety of the closure.
When the superior pole of the patella is reached, the 2 sutures are tied together, thus creating a segmental closure (Figure 3). Following this tie off, the closure is continued in a similar manner until the inferior pole of the patella is reached. The sutures are then tied off to each other again, creating another segmental closure (Figure 4). The remainder of the arthrotomy is closed continuing the Flint Lock technique, and the 2 sutures are tied off to each other at the distal end of the arthrotomy and cut (Figure 5).
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