Incomplete rupture of the quadriceps tendon with complete rupture of the vastus intermedius: Case report and brief review of relevant literature

Abstract

Introduction: Rupture of the quadriceps tendon is an uncommon injury with an incidence of 1.37/100000. Incomplete rupture is characterized as having an intact extensor mechanism while complete rupture presents with an inability to extend the knee. Incomplete ruptures are typically treated non-operatively whereas complete ruptures require surgical intervention. Existing literature reporting partial tears of the tendon is limited. Specifically, isolated vastus intermedius tendon injury has been reported in two case reports thus far. The purpose of this report is to outline the rare case of an incomplete quadriceps tendon rupture with complete rupture of the vastus intermedius, treated with early surgical repair that resulted in an excellent patient outcome. Methods: A 35-year-old male truck driver presented with right knee pain, joint effusion, and decreased range of motion following an injury while jumping in a basketball game. Ultrasonography revealed a partial-thickness tear of the quadriceps tendon with complete rupture of the vastus intermedius. MRI confirmed the diagnosis of a high-grade partial-thickness complete tear involving 60% of the quadriceps tendon with significant retraction of the vastus musculature. It is the opinion of the senior author (JA) that this injury pattern combined with his known extensor lag was unlikely to improve without surgical intervention. This was discussed with the patient and they underwent successful quadriceps tendon repair.Results: Six months post-operatively, the patient had no pain with rest or walking. He had returned to work without limitation. On examination, his gait was normal and knee range of motion was full. There was no tenderness to palpation over the quadriceps tendon and no crepitus with movement. Straight leg raise and single-leg squatting were performed without difficulty. The patient’s quadriceps muscle bulk was approximately 80% of the contralateral side and his power was 5/5.Discussion: This report outlines the rare case of complete vastus intermedius avulsion from the quadriceps tendon, with partial tendon rupture. Similar injuries have traditionally been managed non-operatively. We illustrate how surgical repair can be performed successfully with an excellent clinical outcome. An understanding of predisposing factors for partial tears can also be gained through review of the literature.