Patellar Fracture Fixation Using Suture Tape Cerclage.

Transverse patellar fractures are a relatively common injury and typically require surgical fixation. An adequate restoration of patella integrity is essential for proper functioning of the extensor mechanism of the knee and for the prevention of patellofemoral osteoarthritis. Currently, the treatment of transverse fractures of the patellar bone involves several surgical techniques, most of which involve the use of metallic implants. Despite good clinical results following surgery, numerous complications exist, including primarily symptomatic hardware following surgical treatment. The purpose of this article is to describe the technique for treatment of a transverse patellar fracture using a high-resistance tape (FiberTape; Arthrex) and a tensioner (Arthrex) instead of traditional metallic implants.

Patellar fracture is a common injury for all ages of patients, constituting approximately 1% of all skeletal injuries,, with 70% to 90% of these having a transverse fracture pattern., Most are transverse fractures involving the middle third of the patella in patients aged from 20 to 50 years and affect almost twice as many men as women. Generally accepted indications for surgery are articular step-off of greater than 1 to 2 mm or 2 to 3 mm of diastasis of extra-articular fragments with loss of active knee extension. Although the surgical procedure for patellar fractures appears quite simple, it is, in fact, technically demanding; moreover, wire breakage and migration, painful hardware, and loss of fixation are frequent issues that lead to high reoperation rates because of the need to remove the internal implants.7, 8, 9 Mobilization performed too early may cause re-displacement of the fracture, whereas prolonged immobilization may cause postoperative stiffness and arthrofibrosis. In the present paper, we describe a technique in which we use a high-strength synthetic material and a specific tensioning device in place of the stainless-steel monofilament wire cerclage.

Technique (With Video Illustration)

On initial presentation in the emergency department, radiographic examination of the left knee including both anteroposterior and lateral views (Fig 1 A and B) are obtained. After obtaining informed consent from the patient, the operating room is prepared for the surgical procedure of open reduction and internal fixation of a transverse patellar fracture of the left knee (Video 1). Under spinal anaesthesia and positioning of a tourniquet at the left lower limb, the patient is placed in the supine position on a radiolucent flat top operating table with the left knee in full extension position to facilitate easy access for the C-arm of an image intensifier. The fracture is exposed through a longitudinal or transverse incision of 10 cm on the fracture site (as an alternative it is possible to make a longitudinal incision). After the dieresis of the surgical plane including subcutaneous tissue and the prepatellar bursa, curettage of the fracture is performed. Temporary reduction is performed of the fracture fragments, and confirmation of acceptable reduction is performed with image intensifier. Using a drill, 2.4-mm eyelet Kirschner wire (K-wire) is passed into the base of the patellar bone.

Fig 1

(A) Preoperative radiographic examination of the left knee in extended position showing the transverse fracture of the patella (∗) on coronal view. (B) Preoperative radiographic examination of the left knee in extended position showing the transverse fracture of the patella (∗) on sagittal view.

Once stability of the reduction has been tested, a straight blunt Deschamps needle (Cerclage Passing Hook Large, Reusable; Arthrex, Naples, FL) is placed immediately below the patellar tendon, the suture tape is first passed under the patellar tendon (Fig 2), and then driven through the patellar bone with the aid of the eyelet K-Wire (Fig 3). The high-resistance tape (FiberTape; Arthrex) is assembled and passed circumferentially around the patella tight around the bone (Fig 4). Using the tensioner (Arthrex), the suture tape is tensioned at 80 pound-force (lbf) of applied force (Fig 5). After the tensioning, the reduction is checked by intraoperative fluoroscopy (Fig 6). Once satisfactory reduction has been achieved, 3 simple knots are made, applying 80 lbf force to tighten them through the aforementioned tensioning device. The tensioning values expressed in pound-force (lbf) are visible on a portion of the instrument and it is therefore possible for the surgeon to apply the same value of tensioning to all the nodes that are subsequently tightened. The stability of the reduction and fixation is intraoperatively checked by flexing and extending the knee. The remaining suture tape is cut and the final radiographic postoperative check is performed (Fig 7, A and B). After the closure of peritenoneon and subcutaneous tissue with absorbable sutures the skin is closed with metal staples. The main steps of the surgical procedure described are summarized in Table 1.

Fig 2

Left knee. Cerclage placement step. A straight blunt Deschamps needle (>) is placed immediately below the patellar tendon (∗) and used to pass the high resistance tape under the patellar tendon.

Fig 3

Left knee. Cerclage placement step. The high-resistance tape is driven through the proximal pole of the patella (∗) by the medial to the lateral side with the aid of the eyelet K-wire (<).

Fig 4

Left knee. Cerclage placement step. The high resistance tape is assembled (>) and passed circumferentially around the patella tight around the bone (∗).

Fig 5

Left knee. Cerclage tensioning step. Using the tensioner (∗), the high-resistance tape is tensioned at 80 pound-force (>).

Fig 6

Intraoperative check with image intensifier of the left knee on the sagittal view showing the reduction of the transverse patellar fracture obtained after the tensioning.

Fig 7

(A) Postoperative radiographic examination of the left knee in extended position showing the reduction of the fracture on coronal view. (B) Postoperative radiographic examination of the left knee in extended position showing the reduction of the fracture on sagittal view.

Table 1

Surgical Procedure Main Steps

Patient positioning	Patient is placed supine on a radiolucent flat top operating table with the left knee in full extension; a tourniquet is placed high on the left thigh.
Superficial dissectionExposure of the patellar bursa	Transverse incision is made centered over the patella extended for about 10 cm to the medial and lateral side of the knee.After dieresis of the subcutaneous tissue, the patellar bursa is identified and opened.
Fracture preparation	Hematoma from the fracture site is identified and cleared using curettes and irrigation (identify and remove loose bodies or devitalized fragments).
Fracture reductionIntraoperative reduction check	Fracture reduction using a patellar reduction clamp or a large Weber clamp.Temporary reduction bis confirmed by fluoroscopy intraoperative check in sagittal view of the left knee and by palpating the medial and lateral edges of the patella (congruence of fracture fragments must be acceptable).
Advance the K-wire	2.4-mm eyelet Kirschner wire (K-wire) is passed into the base of the patellar bone from lateral to medial using a conventional drill.
Cerclage placement	A straight blunt Deschamps needle (Cerclage Passing Hook Large, Reusable; Arthrex) is placed immediately below the patellar tendon; it is used to guide the FiberTape (Arthrex) deeply through the patellar tendon.The FiberTape (Arthrex) is then driven through the proximal pole of the patella by pulling out by the medial side the eyelet K-wire with a conventional squared pliers.The high-resistance tape (FiberTape) is passed circumferentially around the patella and assembled tight around the bone as described to follow:♦ Load the tail of the cerclage suture through the suture shuttle (see #1 on the card). ♦ Hold the card at the bullseye (see #2 on the card) and shuttle the cerclage suture through the pretied knot by pulling on the opposite loop (#3 on the card). ♦ Remove the card and discard the suture shuttle.
Cerclage tensioningIntraoperative reduction check	Using the tensioner, (FiberTape Cerclage Tensioner, Reusable; Arthrex) the suture tape is tensioned at 80 pound-force (lbf) of applied force.The obtained reduction is checked by intraoperative fluoroscopy in sagittal view of the left knee.Three simple knots are made and tensioned applying 80 lbf by using the tensioner, (FiberTape Cerclage Tensioner, Reusable; Arthrex).Remaining suture tape is cut and the final radiographic postoperative check is performed.
Wound closure	Closure of peritenoneon with 2-0 VICRYL;Subcutaneous closure with 2-0 VICRYL;Skin closure with metal staples.

Immediately after surgery, the left knee is immobilized in complete extended position with a brace for 4 weeks and skin staples are removed after 14 days. Full weight bearing with assisted device is allowed at 2 weeks using crutches. The patient is followed up biweekly in the first month, both clinically and with conventional radiographs (including lateral and anteroposterior radiographs of the knee). The patient is re-examined at 3 (Fig 8 A and B), 6, and 12 months after surgery. Full range of motion and specific exercises for the recovery of full active flexion of the left knee is allowed at 8 weeks. The patient follows a rehabilitation protocol (Table 2), including isometric exercises for the quadriceps strength recovery, hamstrings stretching exercises, and starts formal physical therapy consisting in progressive and controlled active flexion movements 5 weeks postoperatively with complete range of motion and completion of care at 12 weeks postoperatively.

Fig 8

(A) Twelve weeks postoperative radiographic examination of the left knee showing the fracture healing on coronal view. (B) Twelve weeks postoperative radiographic examination of the left knee showing the fracture healing on sagittal view.

Table 2

Postoperative Rehabilitation Protocol Phases

Phase I: early postoperative0 to 30 days
Recommendation for strictly using a Knee Immobilizer in Extension for 30 days
Day 14	Skin staples are removedProgressive full weight bearing with assisted device is allowed using crutches and maintaining the knee immobilizer in extension
Day 30	The patient's knee immobilizer is removed and a conventional radiographic control is performed (including lateral and anteroposterior radiographs of the knee)

Complete range of motion recovery (complete flexion and extension of the knee);

isometric exercises for the quadriceps strength recovery;

hamstrings stretching exercises; and

start of progressive and controlled active flexion/extension movements

Discussion

The use of the suture tape and the tensioner for the surgical treatment of transverse patellar fractures has proven to be effective both in terms of consolidation of the fracture and functional knee recovery.3, 4, 5, 6, 7, 8, 9, 10 The benefits of using suture tape augmentation include the theoretically reduction in postoperative complications, including wound healing and hardware pain. Over the years, new techniques have been tried out using various non-metallic implants that could reduce the rate of complications related to the synthesis media., The suture tape, as reported by the patients at follow-up controls, does not seem to cause any discomfort due to its presence, unlike metal implants, which in some cases cause pain and discomfort such as to motivate the patient to request a second surgery for removal (Table 3). The tensioning device allows an exact tension to be applied to the suture tape and to the knots, to uniformly cerclage around the patellar bone, giving resistance to the reduction and optimal compression to the fracture fragments (Table 3) in comparison with twisting the stainless-steel wire. Firm fixation of the fracture reduction with controlled tensioning of the high-resistance tape allows early functional exercise and weight bearing, which contributes to excellent-good result in short-term and long-term recovery. Suture tape radiolucency properties allows better sight of the fracture reduction radiographic intra- and postoperative control compared to metallic hardware due to their possible interposition and artifacts (Table 3). During the surgical procedure, after the suture tape closure and tensioning, intraoperative fluoroscopy control of the reduction is required; in case the reduction obtained is not acceptable suture tape has to be loosened, then the fracture has to be re-reduce adequately and the closing and tensioning procedure of the cerclage, intraoperative radiographic fracture reduction control included, has to be repeated from the beginning. The circumferential peripatellar cerclage is the limit of this technique because it is a static conformation and therefore it is not possible to obtain the compression of the fracture during knee flexion. Hence, our recommendation for using a knee immobilizer in extension for 4 weeks after surgery. In terms of patient comfort, it can be considered a limitation of this technique; in fact, to obtain the fracture consolidation, for all the early postoperative period (phase I) the rehabilitative protocol (Table 2) recommendation is knee immobilization in extension for at least 30 days after surgery to avoid the active knee flexion, which can cause a secondary displacement of the reduction due to the tensioning forces of the quadricep transmitted to the patella. In addition, to the detriment of its use compared with the traditional metallic wire cerclage, the suture tape and the special tensioner device are more expensive than the stainless-steel wire. This surgical technique is be technically feasible for the treatment of transverse pattern fractures 34C1 – 34C2 according to the Orthopaedic Trauma Association fracture classification (AO/OTA) system. Even in these cases, the risks of the procedure potentially include knots slippage that could lead to implant loosening or breakage with consequent fixation failure. This risk can be minimized when tensioning step is correctly performed by tightening the knots through the tensioner to proper value of applied force. In conclusion, the use of high-resistance tape (FiberTape; Arthrex) and the tensioner (Arthrex) eliminates the use of metallic hardware, consequently reducing related complications and therefore the need for a second intervention. The treatment of transverse patella fractures can be performed with non-metallic implants advantageously also to reduce health care costs because they reduce the risk of having to perform a second surgery to remove them. In this Technical Note, we have described the surgical technique for treatment of a transverse patellar fracture using a high-resistance tape (FiberTape; Arthrex) and a tensioner (Arthrex) instead of traditional metallic implants.

Table 3

Pearls and Pitfalls

Criteria	Pearls	Pitfalls
Patient comfort	As reported by the patients, the tape suture does not seem to cause any discomfort due to its presence, so they not request a second surgery for its removal.	Immobilization of the knee in extended position is required for at least 4 weeks.A removable knee immobilizer can be used, but lack of both education and compliance on the use of the brace could increase the risk of fracture displacement.
Cerclage tensioning	The tensioner guaranties the correct cerclage tensioning and to intraoperatively check the amount of applied force to the suture tape giving resistance to the reduction and optimal compression to the fracture fragments.	The peripatellar circumferential cerclage technique is a rigid fixation conformation and so does not allow compression of the fracture during the knee flexion.
Radiographic evaluation	Suture tape radiolucency properties allows better sight of the fracture reduction on radiographs compared with metallic hardware due to their interposition and possible artifacts.	After suture tape closure and tensioning, intraoperative fluoroscopy control of the reduction is required; in case the reduction is not acceptable, the suture tape has to be loosened, then re-reduce the fracture adequately and repeat from the beginning the closing and tensioning procedure of the cerclage, intraoperative radiographic fracture reduction control included.