Successful Surgical Repair of Acute Quadriceps Tendon Rupture Utilizing Cortical Button Fixation: A Case Report

Background

Quadriceps tendon rupture can be a debilitating injury that results in loss of the extensor mechanism [1,2]. It commonly affects men older than 40 years of age, usually in the fifth or sixth decade of life [3]. Predisposition to the site of the tear in this age group has been documented to be at the tendon-bone junction [1]. This occurs during an eccentric loading of the extensor mechanism with the foot planted [1]. Furthermore, degenerative changes, microtrauma, diabetes, renal failure, and steroid use contribute to the acute quadriceps tendon rupture [1]. A prompt diagnosis with early surgical management is required to optimize function and restore the extensor mechanism [4].

Various surgical techniques have been described for the treatment of acute quadriceps tendon rupture [4,5]. Regardless of the surgical method, overall outcomes are satisfactory [4]. In contrast to acute repair, chronic quadriceps tendon ruptures are more challenging and may require allografts [1]. Traditionally, repair of acute quadriceps tendon rupture has been by transosseous bone tunnels [6]. However, suture anchor repair has been increasing in use [7].

There is reported literature regarding reconstruction of chronic quadriceps tendon rupture using Endobuttons [8]. However, to the best of our knowledge, there is limited literature documenting cortical button fixation for acute quadriceps tendon rupture. Cortical button fixation, or the use of an adjustable cortical fixation device, is a local and biomechanically strong internal brace technique used to treat ligament and tendon injuries [9]. This report is of a 69-year-old man who experienced a quadriceps tendon rupture while golfing and underwent a successful surgical repair using cortical button fixation.

Case Report

TREATMENT:

The patient was taken to the operating theater, where he was placed supine on a radiolucent table and placed under general anesthesia. A non-sterile tourniquet was applied over the proximal thigh, and the operative extremity was prepped and draped in usual sterile fashion. The operative extremity was exsanguinated, and the tourniquet was inflated to 250 mmHg. A 6-cm incision centered over the superior patellar pole was made, extending from 2 cm proximal to the superior pole to just below the inferior patellar pole. Blunt dissection was performed to identify the quadriceps tendon. As the tendon rupture was close to the patella, a transosseous technique was used [10]. The tendon was mobilized adequately to allow for repair. A #2 Fibertape suture was passed through the lateral aspect of the tendon via a Krackow-type stitch extending 4–5 cm into the proximal portion of the tendon. This was repeated with a second #2 Fibertape suture on the medial aspect of the quadriceps tendon. The lateral and medial suture ends were each passed through 2 Arthrex 12-mm cortical buttons, respectively. An Endobutton 3.2-mm drill bit was used to create a bicortical tunnel that extends inferiorly and medially from the super patellar pole to the inferior one. The medial Fibertape sutures and Endobutton were then passed through the tunnel via the Endobutton insertion device to engage the medial Endobutton at the inferior patellar pole. In similar fashion, a bicorctical tunnel was drilled inferiorly and laterally, and lateral Fibertape sutures and Endobutton were placed. The sutures were toggled on each side to tension the tendon down to its insertion. Surgical knots were tied over the Endobuttons both medially and laterally. The knee was then ranged to 90 degrees without gapping of the quadriceps tendon from the repair site. The tourniquet was released and hemostasis obtained with electrocautery. The wound was copiously irrigated with sterile saline and closed in layered fashion. A dry dressing was applied over the incision as well as an elastic bandage and hinged knee brace locked in extension. The patient was allowed to be weight bearing as tolerated on the operative extremity with knee in full extension in the hinged knee brace.

Postoperatively, the patient was placed in a hinged knee brace and was able to bear weight as tolerated with the knee locked in extension. He was able to gently flex his knee to 45 degrees. He was enrolled in a physical therapy program for quadriceps tendon strengthening but with no active knee extension. At 2 weeks postoperatively, patient was doing well, with a well-healed incision. At the 6-week postoperative visit, the repair was doing well, and the patient had full active extension of his left knee with flexion to 60 degrees. He was noted to have quadriceps atrophy. He was instructed to continue quadriceps strengthening exercises and the brace was removed. At his 3-month postoperative visit, he had progressed well with a 10-degree extension lag and active flexion to 120 degrees and mild quadriceps atrophy. Five months postoperatively, the patient continued to do well and had restored full extension of his left knee with flexion to 110 degrees. He was ambulating without any assistive devices. At this time, the patient had no activity restrictions, and no further follow-up appointments were requested.

Discussion

Acute quadriceps tendon rupture is commonly treated with transosseous suture repair and suture anchor repair [10]. This case report demonstrated successful treatment with cortical button fixation that achieved good outcomes, restored range of motion, and allowed early return to function. The patient presented acutely following an injury while golfing. The diagnosis was suspected clinically due to the loss of the extensor mechanism and the presence of a palpable defect in the area of the quadriceps tendon. Radiographs and magnetic resonance imaging confirmed the diagnosis. Although cortical button fixation is typically used for chronic quadriceps ruptures, this acute rupture was treated with this internal brace technique due to its favorable biomechanical properties [8,9]. This allowed early range of motion postoperatively and prompt resumption of activity. The patient had completed his physical therapy course by his 5-month follow-up. This is in line with other surgical techniques and postoperative rehabilitation, which can take up to 22 weeks for patients to return to pre-injury activity, and the favorable clinical outcomes were similar to what has been reported previously [6,8].

Quadriceps tendon rupture is an uncommon injury, with an incidence of 1.37/100 000 patients per year [11]. Generally, contraction of the extensor mechanism with sudden axial load of a flexed knee will lead to an acute quadriceps tendon rupture [3]. Young patients tend to sustain a midsubstance rupture, and older patients tend to have an osteotendinous junction rupture [12]. A complete tendon rupture will result in the loss of the extensor mechanism, which subsequently leads to long-term knee disability if not promptly addressed [12].

Quadriceps tendon ruptures are seen in male patients typically over 40 years of age and are associated with multiple medical comorbidities [1]. Several systemic conditions are associated with this injury [4,13]. These include systemic lupus erythematosus, rheumatoid arthritis, connective tissue disorders, diabetes, obesity, and chronic renal disease [4,13]. Similarly, systemic steroid use and fluoroquinolones are linked with quadriceps tendon ruptures [4,14]. In addition to surgical repair, postoperative rehabilitation is important for patients to achieve recovery and return to pre-injury function [4,6]. Rehabilitation not only helps with pain control and muscle strengthening but also protects the integrity of the surgical repair [6]. Postoperative rehabilitation regimens may be prolonged and require up to 22 weeks [6]. Our patient had achieved adequate muscle strength and range of motion by his 5-month follow-up visit.

Cortical button fixation has commonly been employed in the repair of distal biceps tendons, anterior cruciate ligament (ACL) reconstruction, suspensionplasty, and proximal bicep tenodesis [16,17]. Cortical button fixation has been compared to different techniques in the context of repairing distal biceps tendon ruptures [18–20]. This construct was shown to be biomechanically superior over traditional bone-tunnel repair, suture anchors, and tenodesis screws regarding pullout strength [18]. The other techniques place stress on the sutures in various ways [18,19]. The bone tunnel places stress on the sutures against sharp cortical bone, allowing for suture failure at the edges [18,19]. The suture button allowed for greater return of strength due the suture being pulled against rounded edges [18,19]. Gould et al compared use of cortical button fixation devices to suture anchor repair in cadaveric knees, which showed superior biomechanical properties in cyclic displacement testing at all testing intervals [9]. Similarly, Ode et al determined that cortical button fixation for patellar tendon repairs had a more favorable biomechanical profile as compared to suture anchor repair [21]. Another advantage of using cortical button fixation has been demonstrated by a 2020 meta-analysis [22], in which the authors compared ACL reconstruction with cortical button fixation versus interference screws and concluded that the former caused a narrower tibial tunnel [22]. The favorable biomechanics of cortical button fixation can lead to earlier mobilization and quicker return to function [9]. This was demonstrated in the present case. The use of cortical button fixation also eliminates the disadvantage of the 3-bone-tunnel technique [23,24]. The placement of 2 tunnels can decrease operative time and weakening of the bone [23,24].

Tendons have the potential to heal with reasonable approximation [1]. The process is initiated with the inflammatory phase to stimulate fibroblast migration [1]. Granulation tissue progresses and proliferates around the tear to lay collagen fibrils in random orientation [1]. Over time, the fibroblast continues to increase and produce more collagen, strengthening the repair. The collagen continues to proliferate and remodel to organize longitudinally-oriented fibrils [1]. Early controlled motion of the tendon stimulates organization and remodeling of the collagen fibers utilizing tensile stress [1]. The early motion decreases scar tissue and increases strength of the tendon, thus resulting in improved clinical outcomes [1]. Early motion with cortical button fixation is another possible advantage of this technique, and this does not seem to negatively impact outcomes, as demonstrated by our patient.

Conclusions

Although acute quadriceps tendon rupture is commonly treated with transosseous suture repair and suture anchor repair, this report demonstrated that cortical button fixation was a successful procedure with strong biomechanical properties, resulting in the early return of function and range of motion.