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Patellar Tendon Rupture with Underlying Systemic Lupus Erythematosus: A Case Report
The Journal of Emergency Medicine, Vol. 43, No. 1, pp. e35– e38, 2012 Copyright © 2012 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$–see front matter
http://dx.doi.org/10.1016/j.jemermed.2009.08.054
Clinical Communications: Adults
PATELLAR TENDON RUPTURE WITH UNDERLYING SYSTEMIC LUPUS ERYTHEMATOSUS: A CASE REPORT Michael Lu,
MD,*
Sandeep Johar,
DO,*
Kenneth Veenema,
MD, MBA,*†
and John Goldblatt,
MD†
*Department of Emergency Medicine and †Department of Orthopaedics, University of Rochester Medical Center, Rochester, New York Reprint Address: Michael Lu, MD, Department of Emergency Medicine, University of Rochester Medical Center, 601 Elmwood Ave, Box 655, Rochester, NY 14642
e Abstract—Background: There have been few case reports of patellar tendon rupture in patients with underlying systemic lupus erythematosus (SLE). Objectives: We present a unique case to discuss the importance of recognizing patellar tendon rupture in the emergency department (ED). Case Report: An 18-year-old man with SLE presented to the ED with pain, swelling, and inability to extend his left knee after a fall. Physical examination demonstrated a palpable defect over the patellar tendon, and plain radiographs showed patella alta. Patellar tendon rupture was diagnosed, and the patient underwent open surgical repair. Conclusion: In low-energy patellar tendon rupture, the effects of the pathophysiology and the treatment for SLE, which includes systemic corticosteroids, are currently unclear. However, it is important to establish prompt diagnosis and appropriate treatment in the ED to maximize recovery and minimize long-term disability. © 2012 Elsevier Inc.
other types of injuries involving the knee joint. Patellar tendon ruptures are less common than quadriceps tendon ruptures and patella fractures. The patellar tendon is extremely resistant to tensile stresses and does not rupture under normal physiologic conditions. Typically, the patellar tendon tends to separate from its insertion point on the inferior pole of the patella in young athletes. However, chronic systemic conditions such as systemic lupus erythematosus (SLE) may render the tendon more vulnerable to rupture. We describe a case of atraumatic patellar tendon rupture in a patient with underlying SLE presenting to the Emergency Department (ED).
CASE REPORT An 18-year-old man presented to our ED complaining of left knee pain and swelling after almost slipping while walking down a flight of stairs, and bracing himself with a flexed left knee. He felt a pop and noticed immediate left knee pain and swelling. He did not sustain any other injuries. His past medical history was significant for SLE with associated chronic kidney disease, arthralgias, and gastroesophageal reflux. He did not have any surgical history. His medications included mycophenolate mofetil, tacrolimus, prednisone, hydroxychloroquine, meloxicam, and omeprazole. He had no known allergies. There was a family history of coronary artery disease, hypertension, and diabetes mellitus, but it was
e Keywords— patellar tendon rupture; systemic lupus erythematosus; patella alta
INTRODUCTION The extensor mechanism of the knee involves the quadriceps muscle, quadriceps tendon, medial and lateral retinacula, patella, patellar tendon, and tibial tubercle. The surrounding soft-tissue structures further stabilize the patella, both passively and dynamically. Disruptions in this extensor mechanism are infrequent compared to
RECEIVED: 7 May 2009; FINAL ACCEPTED: 8 August 2009
SUBMISSION RECEIVED:
4 July 2009; e35
e36
not otherwise significant for SLE or other autoimmune or connective tissue diseases. He was a high school graduate, was living with his family at the time of injury, and denied any tobacco, alcohol, or illicit drug use. The review of systems was negative other than his left knee injury. Physical examination revealed a well-developed young man in no acute distress. His vital signs on ED arrival were the following: blood pressure 137/87 mm Hg, pulse 76 beats/min, respirations 16 breaths/min, temperature 36.9°C, and pain score of 2 on a scale of 10. He was unable to bear weight on his left leg. Examination of the left lower extremity revealed large anterior swelling of the left knee. He was unable to actively extend or keep his leg extended against gravity. There was pain with passive range of motion. A palpable defect was noted over the patellar tendon. There was no joint line tenderness. The ligaments were stable to valgus and varus stress, posterior and anterior drawer tests, and Lachman’s maneuver. Distal neurovascular examination was normal. There were no other signs of injury, and the remainder of his physical examination was normal. Plain radiographs of the left knee were obtained in the ED. The lateral view (Figure 1) demonstrated a highriding patella, anterior swelling, and no other osseous injuries. He was diagnosed with left knee strain and discharged from the ED with a knee immobilizer, crutches, and instructions to avoid weight bearing on his left leg and to follow-up with the Sports Medicine clinic.
Figure 1. Lateral radiograph of the left knee, demonstrating patella alta (Insall-Salvati ratio ⴝ 0.58). LP ⴝ length of the patella; LT ⴝ expected length of the patellar tendon.
M. Lu et al.
The patient appeared in clinic 10 days after his initial ED evaluation. He continued to have persistent swelling, weakness, and inability to bear weight. His physical examination again revealed a significantly swollen left knee, inability to actively extend his knee, and a palpable defect over the patellar tendon. A patellar tendon rupture was diagnosed. He was referred to Orthopedics on the same clinic day for evaluation for open surgical repair. Given the fact that 10 days had passed since the original injury, the decision was made to surgically repair the ruptured patellar tendon the following day. In the operating room, the surgeons found a complete rupture of the mid-substance of the patellar tendon. A direct repair was performed, with secondary reconstruction and augmentation using semitendinosus and gracilis tendon autografts.
DISCUSSION Patellar tendon rupture is an infrequent event, and the true incidence is not known. Among the different causes of disruption of the extensor mechanism of the knee, patellar fracture and quadriceps tendon rupture are more common. Aside from a direct blow, laceration, or posterior knee dislocation, disruption of the knee extensor mechanism occurs as a result of the quadriceps muscle vigorously contracting while the knee is in a flexed position. Patellar tendon rupture usually occurs in athletes and individuals younger than 40 years of age. However, this type of injury may occur under lowerenergy stress in the setting of local corticosteroid injections, systemic inflammatory or rheumatologic disease, chronic renal failure, metabolic disorders, and fluoroquinolone use (1– 4). Atraumatic patellar tendon ruptures in patients with SLE, though extremely rare, have been described in the literature (5–18). One study attempted to characterize the clinical features that might predict rupture (15). Of 180 patients with SLE who were followed within a 10-year period, only 4 patients had a patellar tendon rupture. The authors concluded that tendon rupture in SLE seemed to be associated with extended disease duration (7–20 years), chronic corticosteroid therapy (7–15 years) with evidence of steroid-induced musculoskeletal complications, minimal or no disease activity at the time of rupture, and deforming hand arthropathy. However, it is difficult to determine whether these features represent specific risk factors for patellar tendon rupture in the setting of SLE given the small number of reported cases. The patellar tendon is predisposed to rupture in the setting of SLE due to chronic degenerative and reparative changes and chronic inflammation (18). Histologic findings at the rupture site have shown inflammatory
Patellar Tendon Rupture in Lupus
changes (9). The patellar tendon tends to rupture through the substance of the tendon, as in our case presented here, suggesting that the inflammation weakens the tendon itself. However, a more recent review of the literature shows that most atraumatic patellar tendon ruptures are torn at the inferior pole of the patella or osseotendinous junction, as typically found in acute traumatic injury (16). The role of systemic corticosteroids in patellar tendon rupture is unclear. Despite their anti-inflammatory effects, glucocorticoids may inhibit collagen synthesis or compromise blood supply, thus weakening tendons. However, there are no known reports of patellar tendon rupture in patients taking systemic corticosteroids for conditions like asthma. On the other hand, no cases have been reported in which spontaneous patellar tendon rupture occurred in SLE patients without current or prior systemic corticosteroid use (13). The diagnosis of patellar tendon rupture can be made based on the history and physical examination. The patient may describe a mechanism in which the quadriceps forcefully contracts against a flexed knee, such as when trying to brace against a fall. Physical findings include the inability to extend the knee, swelling, and a palpable defect in the patellar tendon. Plain radiographs will show a superiorly displaced patella, also known as patella alta. The patella position cannot be accurately described relative to the tibiofemoral joint space, which varies based on the amount of flexion or extension in the knee. Instead, the position of the patella may be evaluated with the Insall-Salvati ratio (Figure 2), or the ratio of the greatest length of the patella to the expected length of the
e37
patellar tendon on lateral radiographs (16,19). The patella length (LP) is measured by drawing a straight line from the superior tip to the inferior tip. The expected length of the patellar tendon (LT) is measured from the inferior border of the patella to the tibial tubercle. In a series of 150 normal knees, the LT/LP ratio averaged 1.04, with variations ranging from 0.8 to 1.38 (20). In general, a ratio of ⬍ 0.8 indicates patella alta. Magnetic resonance imaging or ultrasonography may be helpful when the diagnosis is unclear (10,21). A delay in the diagnosis of patellar tendon rupture also has been reported several times in the literature (6,7,17,22,23). In one review, 10 out of 36 ruptures (28%) were misdiagnosed on initial examination and 7 (19%) were repaired more than 2 weeks after the injury (22). In another series involving 11 cases of patellar tendon rupture, all of the cases were misdiagnosed in the ED (23). It is important to consider the possibility of a patellar tendon rupture in any patient who presents with knee swelling, inability to stand or walk, inability to actively extend the knee, or has a palpable defect. Knee examination is often difficult during the acutely injured phase. Having the patient try to lift the heel off the bed may be easier than attempting full extension to 180°. A patient with a partially ruptured tendon still may be able to lift the heel, and is still at risk for complete rupture later on if a partial rupture is not suspected or followedup. Comparing physical and radiographic findings to the contralateral limb also can be very helpful. In the series by Siwek and Rao, 20 (80%) out of 25 patients who underwent immediate surgical repair
Figure 2. The Insall-Salvati ratio in (A) a normal knee and (B) a knee with patella alta. LP ⴝ length of the patella; LT ⴝ expected length of the patellar tendon.
e38
M. Lu et al.
(within 7 days) had excellent post-operative results, whereas 4 (16%) had good results; in contrast, out of the 6 patients who underwent delayed repair (more than 2 weeks after injury), only 2 had excellent results and 1 had an unsatisfactory outcome (22). There are no large series that describe delayed reconstruction of neglected or undiagnosed rupture, although there are a few isolated case reports (24 –26). Prompt diagnosis and surgical repair are important because delayed treatment results in proximal retraction of the patella, scarring, complicated repair, quadriceps atrophy, prolonged recovery time, and diminished long-term function (16).
6. 7. 8. 9. 10. 11. 12.
CONCLUSIONS 13.
The diagnosis of patellar tendon rupture is suggested in patients presenting with the inability to walk or stand, the inability to actively bring the knee joint to full extension, and the lack of osseous injuries on radiographic evaluation. It is also important to be mindful that patients with chronic systemic conditions such as SLE may rupture the patellar tendon under normal physiologic stresses. The role of the underlying chronic inflammation in SLE or the use of chronic systemic corticosteroids remains unclear. Prompt diagnosis, orthopedic referral, and open surgical repair will result in improved patient outcome.
14.
15. 16. 17. 18. 19.
REFERENCES 20. 1. Chen CH, Niu CC, Yang WE, Chen WJ, Shih CH. Spontaneous bilateral patellar tendon rupture in primary hyperparathyroidism. Orthopedics 1999;22:1177–9. 2. Clark SC, Jones MW, Choudhury RR, Smith E. Bilateral patellar tendon rupture secondary to repeated local steroid injections. J Accid Emerg Med 1995;12:300 –1. 3. Kalantar-Zadeh K, Singh K, Kleiner M, Jarrett MP, Luft FC. Nontraumatic bilateral rupture of patellar tendons in a diabetic dialysis patient with secondary hyperparathyroidism. Nephrol Dial Transplant 1997;12:1988 –90. 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. Babini SM, Arturi A, Marcos JC, Babini JC, Iniguez AM, Morteo OG. Laxity and rupture of the patellar tendon in systemic lupus
21. 22. 23. 24. 25. 26.
erythematosus. Association with secondary hyperparathyroidism. J Rheumatol 1988;15:1162–5. Cooney LM, Aversa JM, Newman JH. Insidious bilateral infrapatellar tendon rupture in a patient with systemic lupus erythematosus. Ann Rheum Dis 1980;39:592–5. Cree C, Pillai A, Jones B, Blyth M. Bilateral patellar tendon ruptures: a missed diagnosis: case report and literature review. Knee Surg Sports Traumatol Arthrosc 2007;15:1350 – 4. Formiga F, Moga I, Pac M, Valverde J, Fiter J, Palom X. Spontaneous tendinous rupture in systemic lupus erythematosus. Presentation of two cases. Rev Clin Esp 1993;192:175–7. Furie RA, Chartash EK. Tendon rupture in systemic lupus erythematosus. Semin Arthritis Rheum 1988;18:127–33. Gould ES, Taylor S, Naidich JB, Furie R, Lane L. MR appearance of bilateral, spontaneous patellar tendon rupture in systemic lupus erythematosus. J Comput Assist Tomogr 1987;11:1096 –7. Mayer J, Ilic S, DeHoratius RJ, Messner RP, Hidalgo R. Sequential tendon rupture. Systemic lupus erythematosus. Rocky Mt Med J 1976;73:264. Morgan J, McCarty DJ. Tendon ruptures in patients with systemic lupus erythematosus treated with corticosteroids. Arthritis Rheum 1974;17:1033– 6. Papanikolaou A, Charalambides C, Thanassas C. Letter to the editor: spontaneous simultaneous bilateral patellar tendon rupture in a systemic lupus erythematosus patient. Lupus 2007;16:915–7. Prasad S, Lee A, Clarnette R, Faull R. Spontaneous, bilateral patellar tendon rupture in a woman with previous Achilles tendon rupture and systemic lupus erythematosus. Rheumatology 2003; 42:905– 6. Pritchard CH, Berney S. Patellar tendon rupture in systemic lupus erythematosus. J Rheumatol 1989;16:786 – 8. Rose PS, Frassica FJ. Atraumatic bilateral patellar tendon rupture: a case report and review of the literature. J Bone Joint Surg 2001;83:1382– 6. Strejcek J, Popelka S. Bilateral rupture of the patellar ligaments in systemic lupus erythematosus. Lancet 1969;2:743. Wener JA, Schein AJ. Simultaneous bilateral rupture of the patellar tendon and quadriceps expansions in systemic lupus erythematosus. A case report. J Bone Joint Surg 1974;56:823– 4. Carson WG, James SL, Larson RL, Singer KM, Winternitz WW. Patellofemoral disorders: physical and radiographic evaluation. Part II: Radiographic examination. Clin Orthop 1984;185:178 – 86. Aglietti P, Insall JN, Cerulli G. Patellar pain and incongruence. I: Measurements of incongruence. Clin Orthop Relat Res 1983;176: 217–24. Sochart DH, Shravat BP. Bilateral patellar tendon disruption—a professional predisposition? J Accid Emerg Med 1994;11:255– 6. Siwek CW, Rao JP. Ruptures of the extensor mechanism of the knee joint. J Bone Joint Surg 1981;63:932–7. Bhargava SP, Hynes MC, Dowell JK. Traumatic patella tendon rupture: early mobilization following surgical repair. Injury 2004; 35:76 –9. Takebe K, Hirohata K. Old rupture of the patellar tendon: a case report. Clin Orthop 1985;196:253–5. Ecker ML, Lotke PA, Glazer RM. Late reconstruction of the patellar tendon. J Bone Joint Surg Am 1979;61:884 – 6. Burks RT, Edelson RH. Allograft reconstruction of the patellar ligament: a case report. J Bone Joint Surg Am 1994;76:1077–9.
http://dx.doi.org/10.1016/j.jemermed.2009.08.054
Clinical Communications: Adults
PATELLAR TENDON RUPTURE WITH UNDERLYING SYSTEMIC LUPUS ERYTHEMATOSUS: A CASE REPORT Michael Lu,
MD,*
Sandeep Johar,
DO,*
Kenneth Veenema,
MD, MBA,*†
and John Goldblatt,
MD†
*Department of Emergency Medicine and †Department of Orthopaedics, University of Rochester Medical Center, Rochester, New York Reprint Address: Michael Lu, MD, Department of Emergency Medicine, University of Rochester Medical Center, 601 Elmwood Ave, Box 655, Rochester, NY 14642
e Abstract—Background: There have been few case reports of patellar tendon rupture in patients with underlying systemic lupus erythematosus (SLE). Objectives: We present a unique case to discuss the importance of recognizing patellar tendon rupture in the emergency department (ED). Case Report: An 18-year-old man with SLE presented to the ED with pain, swelling, and inability to extend his left knee after a fall. Physical examination demonstrated a palpable defect over the patellar tendon, and plain radiographs showed patella alta. Patellar tendon rupture was diagnosed, and the patient underwent open surgical repair. Conclusion: In low-energy patellar tendon rupture, the effects of the pathophysiology and the treatment for SLE, which includes systemic corticosteroids, are currently unclear. However, it is important to establish prompt diagnosis and appropriate treatment in the ED to maximize recovery and minimize long-term disability. © 2012 Elsevier Inc.
other types of injuries involving the knee joint. Patellar tendon ruptures are less common than quadriceps tendon ruptures and patella fractures. The patellar tendon is extremely resistant to tensile stresses and does not rupture under normal physiologic conditions. Typically, the patellar tendon tends to separate from its insertion point on the inferior pole of the patella in young athletes. However, chronic systemic conditions such as systemic lupus erythematosus (SLE) may render the tendon more vulnerable to rupture. We describe a case of atraumatic patellar tendon rupture in a patient with underlying SLE presenting to the Emergency Department (ED).
CASE REPORT An 18-year-old man presented to our ED complaining of left knee pain and swelling after almost slipping while walking down a flight of stairs, and bracing himself with a flexed left knee. He felt a pop and noticed immediate left knee pain and swelling. He did not sustain any other injuries. His past medical history was significant for SLE with associated chronic kidney disease, arthralgias, and gastroesophageal reflux. He did not have any surgical history. His medications included mycophenolate mofetil, tacrolimus, prednisone, hydroxychloroquine, meloxicam, and omeprazole. He had no known allergies. There was a family history of coronary artery disease, hypertension, and diabetes mellitus, but it was
e Keywords— patellar tendon rupture; systemic lupus erythematosus; patella alta
INTRODUCTION The extensor mechanism of the knee involves the quadriceps muscle, quadriceps tendon, medial and lateral retinacula, patella, patellar tendon, and tibial tubercle. The surrounding soft-tissue structures further stabilize the patella, both passively and dynamically. Disruptions in this extensor mechanism are infrequent compared to
RECEIVED: 7 May 2009; FINAL ACCEPTED: 8 August 2009
SUBMISSION RECEIVED:
4 July 2009; e35
e36
not otherwise significant for SLE or other autoimmune or connective tissue diseases. He was a high school graduate, was living with his family at the time of injury, and denied any tobacco, alcohol, or illicit drug use. The review of systems was negative other than his left knee injury. Physical examination revealed a well-developed young man in no acute distress. His vital signs on ED arrival were the following: blood pressure 137/87 mm Hg, pulse 76 beats/min, respirations 16 breaths/min, temperature 36.9°C, and pain score of 2 on a scale of 10. He was unable to bear weight on his left leg. Examination of the left lower extremity revealed large anterior swelling of the left knee. He was unable to actively extend or keep his leg extended against gravity. There was pain with passive range of motion. A palpable defect was noted over the patellar tendon. There was no joint line tenderness. The ligaments were stable to valgus and varus stress, posterior and anterior drawer tests, and Lachman’s maneuver. Distal neurovascular examination was normal. There were no other signs of injury, and the remainder of his physical examination was normal. Plain radiographs of the left knee were obtained in the ED. The lateral view (Figure 1) demonstrated a highriding patella, anterior swelling, and no other osseous injuries. He was diagnosed with left knee strain and discharged from the ED with a knee immobilizer, crutches, and instructions to avoid weight bearing on his left leg and to follow-up with the Sports Medicine clinic.
Figure 1. Lateral radiograph of the left knee, demonstrating patella alta (Insall-Salvati ratio ⴝ 0.58). LP ⴝ length of the patella; LT ⴝ expected length of the patellar tendon.
M. Lu et al.
The patient appeared in clinic 10 days after his initial ED evaluation. He continued to have persistent swelling, weakness, and inability to bear weight. His physical examination again revealed a significantly swollen left knee, inability to actively extend his knee, and a palpable defect over the patellar tendon. A patellar tendon rupture was diagnosed. He was referred to Orthopedics on the same clinic day for evaluation for open surgical repair. Given the fact that 10 days had passed since the original injury, the decision was made to surgically repair the ruptured patellar tendon the following day. In the operating room, the surgeons found a complete rupture of the mid-substance of the patellar tendon. A direct repair was performed, with secondary reconstruction and augmentation using semitendinosus and gracilis tendon autografts.
DISCUSSION Patellar tendon rupture is an infrequent event, and the true incidence is not known. Among the different causes of disruption of the extensor mechanism of the knee, patellar fracture and quadriceps tendon rupture are more common. Aside from a direct blow, laceration, or posterior knee dislocation, disruption of the knee extensor mechanism occurs as a result of the quadriceps muscle vigorously contracting while the knee is in a flexed position. Patellar tendon rupture usually occurs in athletes and individuals younger than 40 years of age. However, this type of injury may occur under lowerenergy stress in the setting of local corticosteroid injections, systemic inflammatory or rheumatologic disease, chronic renal failure, metabolic disorders, and fluoroquinolone use (1– 4). Atraumatic patellar tendon ruptures in patients with SLE, though extremely rare, have been described in the literature (5–18). One study attempted to characterize the clinical features that might predict rupture (15). Of 180 patients with SLE who were followed within a 10-year period, only 4 patients had a patellar tendon rupture. The authors concluded that tendon rupture in SLE seemed to be associated with extended disease duration (7–20 years), chronic corticosteroid therapy (7–15 years) with evidence of steroid-induced musculoskeletal complications, minimal or no disease activity at the time of rupture, and deforming hand arthropathy. However, it is difficult to determine whether these features represent specific risk factors for patellar tendon rupture in the setting of SLE given the small number of reported cases. The patellar tendon is predisposed to rupture in the setting of SLE due to chronic degenerative and reparative changes and chronic inflammation (18). Histologic findings at the rupture site have shown inflammatory
Patellar Tendon Rupture in Lupus
changes (9). The patellar tendon tends to rupture through the substance of the tendon, as in our case presented here, suggesting that the inflammation weakens the tendon itself. However, a more recent review of the literature shows that most atraumatic patellar tendon ruptures are torn at the inferior pole of the patella or osseotendinous junction, as typically found in acute traumatic injury (16). The role of systemic corticosteroids in patellar tendon rupture is unclear. Despite their anti-inflammatory effects, glucocorticoids may inhibit collagen synthesis or compromise blood supply, thus weakening tendons. However, there are no known reports of patellar tendon rupture in patients taking systemic corticosteroids for conditions like asthma. On the other hand, no cases have been reported in which spontaneous patellar tendon rupture occurred in SLE patients without current or prior systemic corticosteroid use (13). The diagnosis of patellar tendon rupture can be made based on the history and physical examination. The patient may describe a mechanism in which the quadriceps forcefully contracts against a flexed knee, such as when trying to brace against a fall. Physical findings include the inability to extend the knee, swelling, and a palpable defect in the patellar tendon. Plain radiographs will show a superiorly displaced patella, also known as patella alta. The patella position cannot be accurately described relative to the tibiofemoral joint space, which varies based on the amount of flexion or extension in the knee. Instead, the position of the patella may be evaluated with the Insall-Salvati ratio (Figure 2), or the ratio of the greatest length of the patella to the expected length of the
e37
patellar tendon on lateral radiographs (16,19). The patella length (LP) is measured by drawing a straight line from the superior tip to the inferior tip. The expected length of the patellar tendon (LT) is measured from the inferior border of the patella to the tibial tubercle. In a series of 150 normal knees, the LT/LP ratio averaged 1.04, with variations ranging from 0.8 to 1.38 (20). In general, a ratio of ⬍ 0.8 indicates patella alta. Magnetic resonance imaging or ultrasonography may be helpful when the diagnosis is unclear (10,21). A delay in the diagnosis of patellar tendon rupture also has been reported several times in the literature (6,7,17,22,23). In one review, 10 out of 36 ruptures (28%) were misdiagnosed on initial examination and 7 (19%) were repaired more than 2 weeks after the injury (22). In another series involving 11 cases of patellar tendon rupture, all of the cases were misdiagnosed in the ED (23). It is important to consider the possibility of a patellar tendon rupture in any patient who presents with knee swelling, inability to stand or walk, inability to actively extend the knee, or has a palpable defect. Knee examination is often difficult during the acutely injured phase. Having the patient try to lift the heel off the bed may be easier than attempting full extension to 180°. A patient with a partially ruptured tendon still may be able to lift the heel, and is still at risk for complete rupture later on if a partial rupture is not suspected or followedup. Comparing physical and radiographic findings to the contralateral limb also can be very helpful. In the series by Siwek and Rao, 20 (80%) out of 25 patients who underwent immediate surgical repair
Figure 2. The Insall-Salvati ratio in (A) a normal knee and (B) a knee with patella alta. LP ⴝ length of the patella; LT ⴝ expected length of the patellar tendon.
e38
M. Lu et al.
(within 7 days) had excellent post-operative results, whereas 4 (16%) had good results; in contrast, out of the 6 patients who underwent delayed repair (more than 2 weeks after injury), only 2 had excellent results and 1 had an unsatisfactory outcome (22). There are no large series that describe delayed reconstruction of neglected or undiagnosed rupture, although there are a few isolated case reports (24 –26). Prompt diagnosis and surgical repair are important because delayed treatment results in proximal retraction of the patella, scarring, complicated repair, quadriceps atrophy, prolonged recovery time, and diminished long-term function (16).
6. 7. 8. 9. 10. 11. 12.
CONCLUSIONS 13.
The diagnosis of patellar tendon rupture is suggested in patients presenting with the inability to walk or stand, the inability to actively bring the knee joint to full extension, and the lack of osseous injuries on radiographic evaluation. It is also important to be mindful that patients with chronic systemic conditions such as SLE may rupture the patellar tendon under normal physiologic stresses. The role of the underlying chronic inflammation in SLE or the use of chronic systemic corticosteroids remains unclear. Prompt diagnosis, orthopedic referral, and open surgical repair will result in improved patient outcome.
14.
15. 16. 17. 18. 19.
REFERENCES 20. 1. Chen CH, Niu CC, Yang WE, Chen WJ, Shih CH. Spontaneous bilateral patellar tendon rupture in primary hyperparathyroidism. Orthopedics 1999;22:1177–9. 2. Clark SC, Jones MW, Choudhury RR, Smith E. Bilateral patellar tendon rupture secondary to repeated local steroid injections. J Accid Emerg Med 1995;12:300 –1. 3. Kalantar-Zadeh K, Singh K, Kleiner M, Jarrett MP, Luft FC. Nontraumatic bilateral rupture of patellar tendons in a diabetic dialysis patient with secondary hyperparathyroidism. Nephrol Dial Transplant 1997;12:1988 –90. 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. Babini SM, Arturi A, Marcos JC, Babini JC, Iniguez AM, Morteo OG. Laxity and rupture of the patellar tendon in systemic lupus
21. 22. 23. 24. 25. 26.
erythematosus. Association with secondary hyperparathyroidism. J Rheumatol 1988;15:1162–5. Cooney LM, Aversa JM, Newman JH. Insidious bilateral infrapatellar tendon rupture in a patient with systemic lupus erythematosus. Ann Rheum Dis 1980;39:592–5. Cree C, Pillai A, Jones B, Blyth M. Bilateral patellar tendon ruptures: a missed diagnosis: case report and literature review. Knee Surg Sports Traumatol Arthrosc 2007;15:1350 – 4. Formiga F, Moga I, Pac M, Valverde J, Fiter J, Palom X. Spontaneous tendinous rupture in systemic lupus erythematosus. Presentation of two cases. Rev Clin Esp 1993;192:175–7. Furie RA, Chartash EK. Tendon rupture in systemic lupus erythematosus. Semin Arthritis Rheum 1988;18:127–33. Gould ES, Taylor S, Naidich JB, Furie R, Lane L. MR appearance of bilateral, spontaneous patellar tendon rupture in systemic lupus erythematosus. J Comput Assist Tomogr 1987;11:1096 –7. Mayer J, Ilic S, DeHoratius RJ, Messner RP, Hidalgo R. Sequential tendon rupture. Systemic lupus erythematosus. Rocky Mt Med J 1976;73:264. Morgan J, McCarty DJ. Tendon ruptures in patients with systemic lupus erythematosus treated with corticosteroids. Arthritis Rheum 1974;17:1033– 6. Papanikolaou A, Charalambides C, Thanassas C. Letter to the editor: spontaneous simultaneous bilateral patellar tendon rupture in a systemic lupus erythematosus patient. Lupus 2007;16:915–7. Prasad S, Lee A, Clarnette R, Faull R. Spontaneous, bilateral patellar tendon rupture in a woman with previous Achilles tendon rupture and systemic lupus erythematosus. Rheumatology 2003; 42:905– 6. Pritchard CH, Berney S. Patellar tendon rupture in systemic lupus erythematosus. J Rheumatol 1989;16:786 – 8. Rose PS, Frassica FJ. Atraumatic bilateral patellar tendon rupture: a case report and review of the literature. J Bone Joint Surg 2001;83:1382– 6. Strejcek J, Popelka S. Bilateral rupture of the patellar ligaments in systemic lupus erythematosus. Lancet 1969;2:743. Wener JA, Schein AJ. Simultaneous bilateral rupture of the patellar tendon and quadriceps expansions in systemic lupus erythematosus. A case report. J Bone Joint Surg 1974;56:823– 4. Carson WG, James SL, Larson RL, Singer KM, Winternitz WW. Patellofemoral disorders: physical and radiographic evaluation. Part II: Radiographic examination. Clin Orthop 1984;185:178 – 86. Aglietti P, Insall JN, Cerulli G. Patellar pain and incongruence. I: Measurements of incongruence. Clin Orthop Relat Res 1983;176: 217–24. Sochart DH, Shravat BP. Bilateral patellar tendon disruption—a professional predisposition? J Accid Emerg Med 1994;11:255– 6. Siwek CW, Rao JP. Ruptures of the extensor mechanism of the knee joint. J Bone Joint Surg 1981;63:932–7. Bhargava SP, Hynes MC, Dowell JK. Traumatic patella tendon rupture: early mobilization following surgical repair. Injury 2004; 35:76 –9. Takebe K, Hirohata K. Old rupture of the patellar tendon: a case report. Clin Orthop 1985;196:253–5. Ecker ML, Lotke PA, Glazer RM. Late reconstruction of the patellar tendon. J Bone Joint Surg Am 1979;61:884 – 6. Burks RT, Edelson RH. Allograft reconstruction of the patellar ligament: a case report. J Bone Joint Surg Am 1994;76:1077–9.