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Diagnosis of Patellar Tendon Rupture by Emergency Ultrasound
The Journal of Emergency Medicine, Vol. -, No. -, pp. 1–3, 2014 Copyright Ó 2014 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter
http://dx.doi.org/10.1016/j.jemermed.2014.02.012
Visual Diagnosis in Emergency Medicine
DIAGNOSIS OF PATELLAR TENDON RUPTURE BY EMERGENCY ULTRASOUND Kylee Phillips, MD, MBA and Thomas G. Costantino, MD Department of Emergency Medicine, Temple University Hospital, Philadelphia, Pennsylvania Reprint Address: Kylee Phillips, MD, MBA, Department of Emergency Medicine, Temple University Hospital, 3401 N Broad St, Philadelphia, PA 19140
in a straight leg cylinder cast and successfully completed a long course of rehabilitation.
A 46-year-old man presented to the Emergency Department (ED) with left knee pain after being assaulted and landing on a flexed knee. On physical examination, the patient had a large effusion of his left knee and the patella was retracted proximally. He was unable to bear weight on his left leg, range his knee, or hold his leg up against gravity due to pain. The left extremity was neurovascularly intact. X-ray studies of the knee and femur showed infrapatellar soft tissue swelling but no fracture. A disruption of the extensor mechanism of the knee was suspected, but due to patient discomfort, could not be certainly diagnosed. An ultrasound scan was performed by the emergency physician to evaluate for patellar tendon disruption. It demonstrated a hypoechoic area within the proximal patellar tendon that transversed the entire tendon. Dynamic ultrasound performed while the knee was passively flexed showed a separation of the proximal and distal parts of the patellar tendon with anechoic fluid filling the gap. These findings were consistent with a complete patellar tendon rupture, and Orthopedic Surgery was consulted. Surgery was recommended, and in the operating room, the patella tendon was found to be ruptured near the insertion site on the inferior pole of the patella. After surgical repair, the patient was placed
DISCUSSION The patella tendon originates at the inferior pole of the patella and inserts at the tibial tuberosity. The patella tendon is critical for knee extension along with the quadriceps, medial and lateral retinaculum, and tibia. Patella tendon ruptures often occur at the inferior pole of the patella because this is the site of origin (1). Ruptures of the patella tendon are rare, as the tendon is able to handle very high tensile loads. Rupture requires a force of 17.5 times body weight in a healthy adult (2). Risk for rupture increases in chronic medical conditions such as hyperparathyroidism, rheumatoid arthritis, immunosuppression, systemic lupus erythematosus, and with the use of steroids and fluoroquinolones (3–6). Patella tendon ruptures are more common in patients < 40 years old participating in athletics where the extensor mechanism is overloaded (7). Patients with patella tendon rupture present with sudden onset of pain, swelling, a high-riding patella, and inability to actively extend the leg (1). Diagnosis can be made by physical examination if a complete rupture is present. However, even in complete ruptures, some retinacular fibers may still be intact, allowing extension of the knee (8). In these cases, and in partial tendon ruptures, additional imaging is needed—including radiographs,
Streaming video: One brief real-time video clip that accompanies this article is available in streaming video at www.journals.elsevierhealth.com/periodicals/jem. Click on Video Clip 1.
RECEIVED: 11 September 2013; FINAL SUBMISSION RECEIVED: 11 January 2014; ACCEPTED: 10 February 2014 1
2
K. Phillips and T. G. Costantino
ultrasound, or magnetic resonance imaging (MRI). An anteroposterior and lateral radiograph should be obtained and will demonstrate a high-riding patella as seen in Figure 1 (9). Radiographs also effectively rule out fracture. MRI can be used for diagnosing patella tendon ruptures; however, MRI is not often used in the ED setting due to high cost, lack of availability, and length of time to complete the imaging (10). Ultrasound has proven to be useful in the diagnosis of patella tendon rupture. If a complete rupture is present, hypoechogenicity will be seen over the entire thickness of the tendon, as in
Figure 2. Ultrasound of the Patella Tendon and patella (P) showing hypoechoic fluid (arrow) between the proximal patella tendon (*) and the distal patella tendon (**).
Figure 2 (6). Dynamic ultrasound is even more useful in a complete rupture, showing the two tendon ends separating from each other with echogenic or echolucent fluid filling the space as in Video 1 (11). In partial tendon ruptures, a linear hypoechoic line is seen extending through the tendon that may have wedge-shaped separation on dynamic ultrasound with knee flexion (12). Emergency physicians have demonstrated the ability to accurately diagnose tendon ruptures in other parts of the body (13). Treatment for a ruptured patella tendon is surgical reattachment. Quick diagnosis and prompt surgical treatment greatly improves patient outcomes (9). Furthermore, delays in surgical repair lead to scar tissue formation (14). Nonsurgical management with knee immobilization is not effective for full rupture (6). Surgical repair is required to reestablish the extensor mechanisms of the knee (15). However, if only a partial patellar tendon tear is present, the treatment of choice is knee immobilization in full extension for 4–6 weeks (16). After surgery, patients are placed in a long leg cast for knee immobilization. Eventually, range-of-motion and weight-bearing exercises are implemented (6). REFERENCES
Figure 1. Lateral X-ray of knee demonstrating a high riding patella (arrow) in patellar tendon rupture.
1. Rose PS, Frassica FJ. Atraumatic bilateral patellar tendon rupture, a case report and review of the literature. J Bone Joint Surg Am 2001; 83-A:1382–6. 2. Zernicke RF, Garhammer J, Jobe FW. Human patellar-tendon rupture. J Bone Joint Surg Am 1977;59:179–83. 3. Chen CH, Niu CC, Yang WE, Chen WJ, Shih CH. Spontaneous bilateral patellar tendon rupture in primary hyperparathyroidism. Orthopedics 1999;22:1177–9. 4. Peiro A, Ferrandis R, Garcia L, Alcazar E. Simultaneous and spontaneous bilateral rupture of the patellar tendon in rheumatoid arthritis. A case report. Acta Orthop Scand 1975;46:700–3. 5. Morgan J, McCarty DJ. Tendon ruptures in patients with systemic lupus erythematosus treated with corticosteroids. Arthritis Rheum 1974;17:1033–6. 6. Maffulli N, Wong J. Rupture of the Achilles and patellar tendons. Clin Sports Med 2003;22:761–76.
Diagnosis of Patellar Tendon Rupture by Emergency Ultrasound 7. Enad JG. Patellar tendon ruptures. South Med J 1999;92:563–6. 8. Matava MJ. Patellar tendon ruptures. J Am Acad Orthop Surg 1996; 4:287–96. 9. Levine RJ. Patellar tendon rupture. The importance of timely recognition and repair. Postgrad Med 1996;100:241–2:5–6. 10. Lee MJ, Chow K. Ultrasound of the knee. Seminars Musculoskelet Radiol 2007;11:137–48. 11. Bianchi S, Zwass A, Abdelwahab IF, Banderali A. Diagnosis of tears of the quadriceps tendon of the knee: value of sonography. AJR Am J Roentgenol 1994;162:1137–40. 12. Lian O, Holen KJ, Engebretsen L, Bahr R. Relationship between symptoms of jumper’s knee and the ultrasound characteristics of the patellar tendon among high level male volleyball players. Scand J Med Sci Sports 1996;6:291–6. 13. Wu TS, Roque PJ, Green J, et al. Bedside ultrasound evaluation of tendon injuries. Am J Emerg Med 2012;30:1617–21.
3 14. Siwek CW, Rao JP. Ruptures of the extensor mechanism of the knee joint. J Bone Joint Surg Am 1981;63:932–7. 15. Mehta SV, Lomasney LM, Demos TC, Freedman KB. Radiologic case study. Patellar tendon rupture. Orthopedics 2004;27:438: 522–5. 16. Cooper ME, Selesnick FH. Partial rupture of the distal insertion of the patellar tendon. A report of two cases in professional athletes. Am J Sports Med 2000;28:402–6.
SUPPLEMENTARY DATA Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10. 1016/j.jemermed.2014.02.012.
Streaming video: One brief real-time video clip that accompanies this article is available in streaming video at www.journals.elsevierhealth.com/periodicals/jem. Click on Video Clip 1.
http://dx.doi.org/10.1016/j.jemermed.2014.02.012
Visual Diagnosis in Emergency Medicine
DIAGNOSIS OF PATELLAR TENDON RUPTURE BY EMERGENCY ULTRASOUND Kylee Phillips, MD, MBA and Thomas G. Costantino, MD Department of Emergency Medicine, Temple University Hospital, Philadelphia, Pennsylvania Reprint Address: Kylee Phillips, MD, MBA, Department of Emergency Medicine, Temple University Hospital, 3401 N Broad St, Philadelphia, PA 19140
in a straight leg cylinder cast and successfully completed a long course of rehabilitation.
A 46-year-old man presented to the Emergency Department (ED) with left knee pain after being assaulted and landing on a flexed knee. On physical examination, the patient had a large effusion of his left knee and the patella was retracted proximally. He was unable to bear weight on his left leg, range his knee, or hold his leg up against gravity due to pain. The left extremity was neurovascularly intact. X-ray studies of the knee and femur showed infrapatellar soft tissue swelling but no fracture. A disruption of the extensor mechanism of the knee was suspected, but due to patient discomfort, could not be certainly diagnosed. An ultrasound scan was performed by the emergency physician to evaluate for patellar tendon disruption. It demonstrated a hypoechoic area within the proximal patellar tendon that transversed the entire tendon. Dynamic ultrasound performed while the knee was passively flexed showed a separation of the proximal and distal parts of the patellar tendon with anechoic fluid filling the gap. These findings were consistent with a complete patellar tendon rupture, and Orthopedic Surgery was consulted. Surgery was recommended, and in the operating room, the patella tendon was found to be ruptured near the insertion site on the inferior pole of the patella. After surgical repair, the patient was placed
DISCUSSION The patella tendon originates at the inferior pole of the patella and inserts at the tibial tuberosity. The patella tendon is critical for knee extension along with the quadriceps, medial and lateral retinaculum, and tibia. Patella tendon ruptures often occur at the inferior pole of the patella because this is the site of origin (1). Ruptures of the patella tendon are rare, as the tendon is able to handle very high tensile loads. Rupture requires a force of 17.5 times body weight in a healthy adult (2). Risk for rupture increases in chronic medical conditions such as hyperparathyroidism, rheumatoid arthritis, immunosuppression, systemic lupus erythematosus, and with the use of steroids and fluoroquinolones (3–6). Patella tendon ruptures are more common in patients < 40 years old participating in athletics where the extensor mechanism is overloaded (7). Patients with patella tendon rupture present with sudden onset of pain, swelling, a high-riding patella, and inability to actively extend the leg (1). Diagnosis can be made by physical examination if a complete rupture is present. However, even in complete ruptures, some retinacular fibers may still be intact, allowing extension of the knee (8). In these cases, and in partial tendon ruptures, additional imaging is needed—including radiographs,
Streaming video: One brief real-time video clip that accompanies this article is available in streaming video at www.journals.elsevierhealth.com/periodicals/jem. Click on Video Clip 1.
RECEIVED: 11 September 2013; FINAL SUBMISSION RECEIVED: 11 January 2014; ACCEPTED: 10 February 2014 1
2
K. Phillips and T. G. Costantino
ultrasound, or magnetic resonance imaging (MRI). An anteroposterior and lateral radiograph should be obtained and will demonstrate a high-riding patella as seen in Figure 1 (9). Radiographs also effectively rule out fracture. MRI can be used for diagnosing patella tendon ruptures; however, MRI is not often used in the ED setting due to high cost, lack of availability, and length of time to complete the imaging (10). Ultrasound has proven to be useful in the diagnosis of patella tendon rupture. If a complete rupture is present, hypoechogenicity will be seen over the entire thickness of the tendon, as in
Figure 2. Ultrasound of the Patella Tendon and patella (P) showing hypoechoic fluid (arrow) between the proximal patella tendon (*) and the distal patella tendon (**).
Figure 2 (6). Dynamic ultrasound is even more useful in a complete rupture, showing the two tendon ends separating from each other with echogenic or echolucent fluid filling the space as in Video 1 (11). In partial tendon ruptures, a linear hypoechoic line is seen extending through the tendon that may have wedge-shaped separation on dynamic ultrasound with knee flexion (12). Emergency physicians have demonstrated the ability to accurately diagnose tendon ruptures in other parts of the body (13). Treatment for a ruptured patella tendon is surgical reattachment. Quick diagnosis and prompt surgical treatment greatly improves patient outcomes (9). Furthermore, delays in surgical repair lead to scar tissue formation (14). Nonsurgical management with knee immobilization is not effective for full rupture (6). Surgical repair is required to reestablish the extensor mechanisms of the knee (15). However, if only a partial patellar tendon tear is present, the treatment of choice is knee immobilization in full extension for 4–6 weeks (16). After surgery, patients are placed in a long leg cast for knee immobilization. Eventually, range-of-motion and weight-bearing exercises are implemented (6). REFERENCES
Figure 1. Lateral X-ray of knee demonstrating a high riding patella (arrow) in patellar tendon rupture.
1. Rose PS, Frassica FJ. Atraumatic bilateral patellar tendon rupture, a case report and review of the literature. J Bone Joint Surg Am 2001; 83-A:1382–6. 2. Zernicke RF, Garhammer J, Jobe FW. Human patellar-tendon rupture. J Bone Joint Surg Am 1977;59:179–83. 3. Chen CH, Niu CC, Yang WE, Chen WJ, Shih CH. Spontaneous bilateral patellar tendon rupture in primary hyperparathyroidism. Orthopedics 1999;22:1177–9. 4. Peiro A, Ferrandis R, Garcia L, Alcazar E. Simultaneous and spontaneous bilateral rupture of the patellar tendon in rheumatoid arthritis. A case report. Acta Orthop Scand 1975;46:700–3. 5. Morgan J, McCarty DJ. Tendon ruptures in patients with systemic lupus erythematosus treated with corticosteroids. Arthritis Rheum 1974;17:1033–6. 6. Maffulli N, Wong J. Rupture of the Achilles and patellar tendons. Clin Sports Med 2003;22:761–76.
Diagnosis of Patellar Tendon Rupture by Emergency Ultrasound 7. Enad JG. Patellar tendon ruptures. South Med J 1999;92:563–6. 8. Matava MJ. Patellar tendon ruptures. J Am Acad Orthop Surg 1996; 4:287–96. 9. Levine RJ. Patellar tendon rupture. The importance of timely recognition and repair. Postgrad Med 1996;100:241–2:5–6. 10. Lee MJ, Chow K. Ultrasound of the knee. Seminars Musculoskelet Radiol 2007;11:137–48. 11. Bianchi S, Zwass A, Abdelwahab IF, Banderali A. Diagnosis of tears of the quadriceps tendon of the knee: value of sonography. AJR Am J Roentgenol 1994;162:1137–40. 12. Lian O, Holen KJ, Engebretsen L, Bahr R. Relationship between symptoms of jumper’s knee and the ultrasound characteristics of the patellar tendon among high level male volleyball players. Scand J Med Sci Sports 1996;6:291–6. 13. Wu TS, Roque PJ, Green J, et al. Bedside ultrasound evaluation of tendon injuries. Am J Emerg Med 2012;30:1617–21.
3 14. Siwek CW, Rao JP. Ruptures of the extensor mechanism of the knee joint. J Bone Joint Surg Am 1981;63:932–7. 15. Mehta SV, Lomasney LM, Demos TC, Freedman KB. Radiologic case study. Patellar tendon rupture. Orthopedics 2004;27:438: 522–5. 16. Cooper ME, Selesnick FH. Partial rupture of the distal insertion of the patellar tendon. A report of two cases in professional athletes. Am J Sports Med 2000;28:402–6.
SUPPLEMENTARY DATA Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10. 1016/j.jemermed.2014.02.012.
Streaming video: One brief real-time video clip that accompanies this article is available in streaming video at www.journals.elsevierhealth.com/periodicals/jem. Click on Video Clip 1.