Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-014-2947-z
KNEE
Prevalence and consequences of delayed diagnosis of anterior cruciate ligament ruptures M. H. Arastu • S. Grange • R. Twyman
Received: 19 March 2013 / Accepted: 11 March 2014 Ó Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Rupture of the anterior cruciate ligament (ACL) is a common injury, often presenting with a typical injury pattern. Historically, the literature indicates that the accuracy of diagnosis of ACL ruptures is poor at the initial medical consultation. The aims of this study were to determine: the mechanism of injury; changes in accuracy of diagnosis of ACL ruptures at initial presentation over the last decade; and the effect of subsequent delay in diagnosis and definitive treatment. Methods A prospective cohort of one hundred and thirtytwo consecutive patients who underwent ACL reconstruction between 2005 and 2009 were analysed. The median age of the patients was 18 years (12–57). Sixteen patients were excluded due to chronic ACL injury. Results One hundred and sixteen patients (117 ACL ruptures) were included in the analysis. A typical injury pattern was documented in 87 (74.4 %) of cases. The most common sporting activities associated with an ACL injury were football (35.3 %), skiing (21.6 %) and rugby (10.3 %). The majority of patients (67.5 %) sought medical attention within 1 week from time of injury. The correct diagnosis of an ACL rupture was made in 33 cases (28.2 %) at the initial medical consultation. The diagnosis was made following medical consultation in 13 (11.1 %) of
M. H. Arastu (&) Queens Medical Centre, Nottingham, UK e-mail: [email protected] S. Grange Alberta Bone & Joint Health Institute, University of Calgary, Calgary, AB, Canada R. Twyman Epsom and St Helier Hospitals NHS Trust, Surrey, UK
cases with the use of magnetic resonance imaging and 6 (5.1 %) cases at arthroscopy. The median time to diagnosis was 6 weeks (0–192), and the median time to ACL reconstruction was 24 weeks (1–240). A delay in diagnosis of [6 months was associated with a medial meniscal tear rate of 72.2 % compared to 23.1 % if the diagnosis was made within 4 months of the injury (p \ 0.05). Conclusions Despite a ‘typical’ mechanism of injury leading to ACL rupture, the rate of initial diagnosis in the UK still remains poor. This often leads to an unnecessary delay in the diagnosis and subsequent treatment and increases the risk of secondary injury to the knee. A delay in diagnosis of [6 months was associated with an increased medial meniscal tear rate. Patients who present with a ‘typical’ injury pattern should therefore be referred for further assessment by a knee specialist within 6 weeks. Level of evidence IV. Keywords Knee Injury Anterior cruciate ligament Meniscus Diagnosis Delay
Introduction Rupture of the anterior cruciate ligament (ACL) is a common injury [5]. The ‘typical’ pattern of injury commonly indicative of an ACL injury is a low-velocity twisting injury or valgus/external rotation strain; with or without an audible ‘pop’ or ‘snap’; with immediate pain and swelling (within 4 h) implying a haemarthrosis [3]. Within 1–2 weeks, a feeling of subjective improvement and recommencement of the ability to bear weight through the injured knee occurs. The patient often realizes that they have sustained a significant injury and often seek medical attention early (Fig. 1). Historically, the
123
Knee Surg Sports Traumatol Arthrosc
Fig. 1 Typical pattern of injury indicative of ACL rupture
accuracy of diagnosis has been poor despite many patients reporting a ‘typical’ injury pattern and having unequivocal physical signs [3]. At initial medical consultation, the rate of correctly diagnosing an ACL injury between 1980 and 2008 has varied from 6.8 to 25.9 %, respectively [3, 9, 11, 12, 17]. ACL ruptures and knee instability have been associated with an increased risk of developing secondary osteoarthritis [14]. The ability of ACL reconstructive surgery to prevent secondary osteoarthritis is still unknown; however, greater stability from reconstruction may be protective [4]. The delay in diagnosis of an ACL rupture increases the risk of secondary damage to the knee [6–8, 15, 20]. Failure of accurate diagnosis has obvious consequences for the patient who may require repeated medical consultations, attempt return to sports resulting in further damage to the knee and the associated economic burden of this. The primary aim of this study was to re-evaluate the accuracy of diagnosis of ACL ruptures at initial medical consultation with the hypothesis that this has not significantly changed over the last decade. The secondary aims were to determine the mechanism of injury (‘typical’ or ‘atypical’) and whether early diagnosis can minimize the risk of secondary damage to the knee.
Table 1 Mechanism of injury
Materials and methods
Statistical analysis
One hundred and thirty-two consecutive patients who underwent ACL reconstruction between 2005 and 2009 were analysed using prospectively collected data. The median age of the patients was 18 years (12–57). There were 78 (67 %) males and 38 (33 %) females. Sixteen patients were excluded due to chronic ACL injury (defined by delayed presentation following initial correct diagnosis being made and elected non-surgical management pursued) leaving 116 patients (117 knees) for inclusion in the study. Patients with other ligamentous injuries requiring surgical intervention were excluded. The mechanism of injury, associated activity, an audible ‘pop or snap’ and whether this fitted a ‘typical’ or
Statistical analysis was conducted using a paired t test (SPSS v19, SPSS Inc., Chicago, Illinois, and EXCEL, MicrosoftTM, WA). Significance was demonstrated by a p value B0.05.
123
Mechanism of injury
N (%)
Twisting
84 (72)
Direct blow
13 (11)
Hyperextension
5 (4)
Valgus/external rotation force
2 (2)
Not available
13 (11)
‘atypical’ injury pattern was recorded. The time period between injury and initial medical consultation and the accuracy of diagnosis were determined. The grade of medical practitioner was recorded at the initial medical consultation, and what diagnostic tests were used in order to diagnose an ACL rupture. The time interval between injury, accurate diagnosis and ACL reconstruction was also recorded. If patients had either received a magnetic resonance imaging (MRI) scan or undergone knee arthroscopy prior to ACL reconstruction, the findings were recorded and a comparison made to arthroscopic findings at the time of ACL reconstruction. At the time of ACL reconstruction, injury patterns including meniscal tears and chondral damage were recorded. Ethical approval was obtained from the London Surrey Borders Research Ethics Committee.
Results The mechanism of injury (Table 1) and associated activity recorded with injury was football (35 %), rugby (33 %) and skiing (10 %). An audible ‘pop or snap’ was recorded in 40 (34.2 %), not in 69 (60 %) and unknown in 8 (6.8 %) of cases. A ‘typical’ injury pattern was recorded in 87
Knee Surg Sports Traumatol Arthrosc
(74.4 %), ‘atypical’ in 27 (23.1 %) and unknown in 3 (2.6 %) of cases. The time to initial medical consultation following the injury was between immediate and 72 weeks Table 2 Diagnosis made at initial medical consultation following ACL rupture
4(3.4)
5(4.3)
Pivot shift
97 (82.9)
6(5.1)
14(12)
ACL rupture
33
No diagnosis
39
Positive (?ve) and negative (-ve) results of the Lachman and pivot shift test were recorded. In some cases, the tests could not be performed due to the patient not being able to tolerate them
Medial meniscal tear
12
Medial collateral ligament
12
Lateral collateral ligament
3 7 11
Patients (N)
Correct diagnosis (%)
58
12
Primary care physician Primary care physician and physiotherapist
16 4
19 25
Physiotherapist
11
36
4
50
Table 4 The clinical tests performed by the different grade of medical practitioner at time of initial medical consultation following injury. The mean time interval between injury and medical consultation and also the mean time to correct diagnosis of ACL injury is shown
Not possible N (%)
108 (92.3)
Emergency department practitioner
Orthopaedic consultant
-ve N (%)
Lachman
Table 3 Grade of medical practitioner at initial medical consultation and accuracy of diagnosis of ACL rupture
Ski resort doctor
?ve N (%)
Cases (N)
Not available
Orthopaedic resident
Test
Injury
Other
Grade
Table 5 The use of the Lachman and pivot shift tests in ACL deficient knees
11
73
7
100
(median = 0 weeks) and 79 (67.5 %) sought medical attention within 1 week of injury. The correct diagnosis of ACL rupture was made in 33 (28.2 %) of cases at initial consultation. If the diagnosis of an ACL rupture had not been made, the other diagnoses made at the initial medical consultation are shown in Table 2. The median number of medical consultations before the correct diagnosis of an ACL rupture was made in this series was 3 (1–6). The grade of medical practitioner and accuracy of diagnosing ACL rupture is shown in Table 3. The accuracy of diagnosis between the typical and atypical injury groups was 33.3 and 11.1 %, respectively (non-significant). Table 4 shows the clinical tests recorded by different medical practitioners, the time interval between injury and seeking medical attention and also the time interval from injury to diagnosis. Table 5 shows the use of the Lachman and pivot shift tests to correctly diagnose ACL rupture. The diagnosis was made in 13 (11.1 %) of cases with the use of MRI and 6 (5.1 %) cases at arthroscopy. In the cases where an MRI scan/arthroscopy was performed
Clinical test performed None documented Orthopaedic consultant (N = 7) Emergency department physician (N = 55)
Anterior drawer
Lachman
Pivot shift
Median time to 1st medical consultation (weeks, range)
Median time to diagnosis (weeks, range)
0
0
7
6
0 (0–4)
1 (0–4)
45
10
0
0
0 (0–8)
5 (0–156)
3
3
0
0
1 (0–4)
8 (1–20)
9
0
2
0
0 (0–52)
5 (1–20)
Primary care physician (N = 20)
17
0
3
0
5 (0–72)
20 (2–192)
Ski resort doctor (N = 11)
11
0
0
0
0 (0)
Emergency department (nurse practitioner), (N = 3) Physiotherapist (N = 11)
5 (0–32)
123
Knee Surg Sports Traumatol Arthrosc Table 6 Associated injuries found at time of ACL reconstruction compared to time interval from injury Delay in diagnosis (months)
Medial meniscal tear (%)
Lateral meniscal tear (%)
Chondral injury (%)
0–4 (N = 52)
23.1
32.7
11.5
72.2
7.7
16.7
–
–
[6 (N = 18) p value
\0.05
before the ACL reconstruction, there were no significant differences between the MRI scan/arthroscopy findings and at the time of ACL reconstruction. The median time to diagnosis was 6 weeks (0–192), and the median time to ACL reconstruction was 24 weeks (1–240). Associated injuries recorded at the time of ACL reconstruction included medial meniscal tear (N = 46, 39.3 %), lateral meniscal tear (N = 36, 30.8 %) and chondral damage (N = 37, 31.6 %). The effect of timing of surgery on injury pattern identified is shown in Table 6.
Discussion The most important finding of the present study was that the mechanism of injury that results in rupture of the ACL often follows a ‘typical pattern’ and patients present with unequivocal physical signs, but despite this, the accuracy of diagnosis has been, and remains poor [3]. In this series, the accuracy of diagnosis was 28.2 % of cases at the initial medical consultation despite 74.4 % of patients describing a ‘typical’ injury pattern and 67.5 % seeking medical attention within a week following the injury. This supports the hypothesis that the accuracy of diagnosis has not significantly changed significantly in the last decade. The ‘typical’ injury pattern, which should prompt early referral to a knee specialist or for further investigation, includes reporting of points listed in Fig. 1. The median number of outpatient attendances leading to the correct diagnosis being made was 3 (1–6), which inevitably delays appropriate treatment. The delay in diagnosis has obvious consequences for the patient in terms of both sustaining secondary damage to the knee due to instability, socioeconomic burden and delay in return to work and also health economic cost savings. In the current economic, climate trying to deliver health care as efficiently as possible is an obvious priority. A recent study by Ball and Haddad has shown that an open access ‘Acute Knee Clinic’ can reduce the time interval to diagnosis of various soft tissue knee injuries and improve the efficiency of treatment with particular reference to ACL injuries [1]. The grade of medical practitioner who initially assesses patients with an acute ACL rupture will often be junior
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medical staff in the emergency department. The examination of an acutely injured knee is difficult due to pain and haemarthrosis. Performing specialist tests in order to accurately diagnose, an ACL rupture takes experience. The importance of the history is therefore paramount in making the diagnosis of an ACL rupture. Guillodo et al. [11] has shown that a substantial proportion of ACL ruptures were missed by emergency department doctors compared to sports physicians. In our study, the majority 89 (76.1 %) of patients were either first seen by an emergency department practitioner, primary care doctor or physiotherapist. The documentation of the special tests performed in order to ascertain ACL injuries was poorly recorded. However, where it was documented, the anterior drawer test was almost exclusively used by non-specialists. The poor diagnostic rate recorded in this study is multifactorial. Possible contributing factors to this may be a ‘lack of awareness’ or a low index of suspicion of the possible diagnosis. The difficulty with clinical examination, in the acute stage post injury, will improve over a few weeks and the reliance on further investigations in order to make the diagnosis. Rose and Gold reported that there was no significant difference in diagnostic accuracy between MRI and clinical examination performed by a knee specialist in complete ACL deficient knees [19]. Kocabey et al. [13] stated that, ‘a well trained, qualified surgeon can rely on clinical examination’ in order to diagnose an ACL rupture. The anterior drawer test is less useful in the acute ACL deficient knee (sensitivity 49 %, specificity 58 %) than the Lachman test, which is the most valid clinical test (sensitivity 85 %, specificity 94 %), and the pivot shift test, which is the most specific (98 %) but lacks sensitivity (24 %) [2]. In the outpatient clinic setting, the Lachman test has been shown to have the highest sensitivity for diagnosing an acute, complete ACL rupture but when the examination was performed under anaesthesia, the Lachman test still obtained the highest sensitivity, but the pivot shift test was the most specific illustrating the difficulty of performing the pivot shift test on an awake patient [21]. The Lachman and pivot shift test were possible to perform by an experienced orthopaedic surgeon in the majority of the cases in this study and were positive in 92.3 and 82.9 %, respectively. The Lachman and pivot shift tests could not be performed in 4.3 and 12 %, respectively, in the outpatient clinic due to pain. Church and Keating have shown that delays in reconstructive surgery of 12 months or greater increases the incidence of both meniscal tears and degenerative change compared to patients who have reconstructive surgery \12 months from injury [7]. O’Connor et al. [18] performed a retrospective analysis of 1,375 patients with an ACL rupture and the risk of meniscal injury and chondral damage increased with a delay of 6 months or more and 12 months or more, respectively. Sri-Ram et al. [20]
Knee Surg Sports Traumatol Arthrosc
reviewed 5,086 patients in order to determine the incidence of secondary pathology with respect to the time between injury and reconstruction and concluded that ideally, and particularly in younger patients, ACL reconstruction should not be delayed more than 5 months from injury. A similar time-dependent delay to reconstructive surgery has been shown to increase the incidence of secondary damage to the paediatric population also [16]. Frobell et al. [10] reported in young, active adults with acute ACL ruptures, a strategy of rehabilitation plus early ACL reconstruction was not superior to a strategy of rehabilitation plus optional delayed ACL reconstruction. Interestingly, the fact that the ACL rupture was diagnosed early and supervised rehabilitation initiated may explain the lack of secondary knee damage observed in this prospective randomized controlled trial. In this study, the incidence of meniscal injury and chondral damage appeared greater in patients having ACL reconstruction after 6 months following injury compared to those within 4 months following injury. This may be an indirect result of delay in diagnosis. Patients who are told that there is no significant knee injury will attempt return to activities that could result in further secondary damage to the knee. Interestingly, patients who underwent either an MRI scan or arthroscopy prior to ACL reconstruction were found not to have further meniscal or chondral damage to the knee. This supports the theory that interim activity modification between diagnosis and treatment may have an important role in preventing further knee damage. The limitations of this study were that only patients who had ACL reconstruction were included so there may be selection bias. The number of patients studied was small. Conclusions This study highlights that the diagnostic accuracy of ACL ruptures is still low. In order to improve this, the education of emergency department, primary care and physiotherapy practitioners may be beneficial in terms of recognizing the history of a ‘typical’ injury pattern. Improving diagnostic accuracy with the use of the Lachman and pivot shift test performed by non-specialists may not be successful as these tests can be difficult to perform in the acutely injured knee.
References 1. Ball S, Haddad FS (2010) The impact of an acute knee clinic. Ann R Coll Surg Engl 92(8):685–688 2. Benjaminse A, Gokeler A, van der Schans CP (2006) Clinical diagnosis of an anterior cruciate ligament rupture: a meta-analysis. J Orthop Sports Phys Ther 36(5):267–288 3. Bollen SR, Scott BW (1996) Rupture of the anterior cruciate ligament–a quiet epidemic? Injury 27(6):407–409
4. Bourke HE, Gordon DJ, Salmon LJ, Waller A, Linklater J, Pinczewski LA (2012) The outcome at 15 years of endoscopic anterior cruciate ligament reconstruction using hamstring tendon autograft for ‘isolated’ anterior cruciate ligament rupture. J Bone Joint Surg Br 94(5):630–637 5. Brophy RH, Wright RW, Matava MJ (2009) Cost analysis of converting from single-bundle to double-bundle anterior cruciate ligament reconstruction. Am J Sports Med 37(4):683–687 6. Chhadia AM, Inacio MC, Maletis GB, Csintalan RP, Davis BR, Funahashi TT (2011) Are meniscus and cartilage injuries related to time to anterior cruciate ligament reconstruction? Am J Sports Med 39(9):1894–1899 7. Church S, Keating JF (2005) Reconstruction of the anterior cruciate ligament: timing of surgery and the incidence of meniscal tears and degenerative change. J Bone Joint Surg Br 87(12):1639–1642 8. Foster A, Butcher C, Turner PG (2005) Changes in arthroscopic findings in the anterior cruciate ligament deficient knee prior to reconstructive surgery. Knee 12(1):33–35 9. Fowler PJ, Regan WD (1987) The patient with symptomatic chronic anterior cruciate ligament insufficiency. Results of minimal arthroscopic surgery and rehabilitation. Am J Sports Med 15(4):321–325 10. Frobell RB, Roos EM, Roos HP, Ranstam J, Lohmander LS (2010) A randomized trial of treatment for acute anterior cruciate ligament tears. N Engl J Med 363(4):331–342 11. Guillodo Y, Rannou N, Dubrana F, Lefevre C, Saraux A (2008) Diagnosis of anterior cruciate ligament rupture in an emergency department. J Trauma 65(5):1078–1082 12. Hartnett N, Tregonning RJ (2001) Delay in diagnosis of anterior cruciate ligament injury in sport. N Z Med J 114(1124):11–13 13. Kocabey Y, Tetik O, Isbell WM, Atay OA, Johnson DL (2004) The value of clinical examination versus magnetic resonance imaging in the diagnosis of meniscal tears and anterior cruciate ligament rupture. Arthroscopy 20(7):696–700 14. Lohmander LS, Englund PM, Dahl LL, Roos EM (2007) The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis. Am J Sports Med 35(10):1756–1769 15. Michalitsis S, Vlychou M, Malizos KN, Thriskos P, Hantes ME (2013) Meniscal and articular cartilage lesions in the anterior cruciate ligament-deficient knee: correlation between time from injury and knee scores. Knee Surg Sports Traumatol Arthrosc. doi:10.1007/s00167-013-2497-9 16. Millett PJ, Willis AA, Warren RF (2002) Associated injuries in pediatric and adolescent anterior cruciate ligament tears: does a delay in treatment increase the risk of meniscal tear? Arthroscopy 18(9):955–959 17. Noyes FR, Paulos L, Mooar LA, Signer B (1980) Knee sprains and acute knee hemarthrosis: misdiagnosis of anterior cruciate ligament tears. Phys Ther 60(12):1596–1601 18. O’Connor KM, Monteiro SK, Hoelker IA (2009) Comparison of selected lateral cutting activities used to assess ACL injury risk. J Appl Biomech 25(1):9–21 19. Rose NE, Gold SM (1996) A comparison of accuracy between clinical examination and magnetic resonance imaging in the diagnosis of meniscal and anterior cruciate ligament tears. Arthroscopy 12(4):398–405 20. Sri-Ram K, Salmon LJ, Pinczewski LA, Roe JP (2013) The incidence of secondary pathology after anterior cruciate ligament rupture in 5,086 patients requiring ligament reconstruction. Bone Joint J 95-B(1):59–64 21. van Eck CF, van den Bekerom MP, Fu FH, Poolman RW, Kerkhoffs GM (2013) Methods to diagnose acute anterior cruciate ligament rupture: a meta-analysis of physical examinations with and without anaesthesia. Knee Surg Sports Traumatol Arthrosc 21(8):1895–1903
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KNEE
Prevalence and consequences of delayed diagnosis of anterior cruciate ligament ruptures M. H. Arastu • S. Grange • R. Twyman
Received: 19 March 2013 / Accepted: 11 March 2014 Ó Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Rupture of the anterior cruciate ligament (ACL) is a common injury, often presenting with a typical injury pattern. Historically, the literature indicates that the accuracy of diagnosis of ACL ruptures is poor at the initial medical consultation. The aims of this study were to determine: the mechanism of injury; changes in accuracy of diagnosis of ACL ruptures at initial presentation over the last decade; and the effect of subsequent delay in diagnosis and definitive treatment. Methods A prospective cohort of one hundred and thirtytwo consecutive patients who underwent ACL reconstruction between 2005 and 2009 were analysed. The median age of the patients was 18 years (12–57). Sixteen patients were excluded due to chronic ACL injury. Results One hundred and sixteen patients (117 ACL ruptures) were included in the analysis. A typical injury pattern was documented in 87 (74.4 %) of cases. The most common sporting activities associated with an ACL injury were football (35.3 %), skiing (21.6 %) and rugby (10.3 %). The majority of patients (67.5 %) sought medical attention within 1 week from time of injury. The correct diagnosis of an ACL rupture was made in 33 cases (28.2 %) at the initial medical consultation. The diagnosis was made following medical consultation in 13 (11.1 %) of
M. H. Arastu (&) Queens Medical Centre, Nottingham, UK e-mail: [email protected] S. Grange Alberta Bone & Joint Health Institute, University of Calgary, Calgary, AB, Canada R. Twyman Epsom and St Helier Hospitals NHS Trust, Surrey, UK
cases with the use of magnetic resonance imaging and 6 (5.1 %) cases at arthroscopy. The median time to diagnosis was 6 weeks (0–192), and the median time to ACL reconstruction was 24 weeks (1–240). A delay in diagnosis of [6 months was associated with a medial meniscal tear rate of 72.2 % compared to 23.1 % if the diagnosis was made within 4 months of the injury (p \ 0.05). Conclusions Despite a ‘typical’ mechanism of injury leading to ACL rupture, the rate of initial diagnosis in the UK still remains poor. This often leads to an unnecessary delay in the diagnosis and subsequent treatment and increases the risk of secondary injury to the knee. A delay in diagnosis of [6 months was associated with an increased medial meniscal tear rate. Patients who present with a ‘typical’ injury pattern should therefore be referred for further assessment by a knee specialist within 6 weeks. Level of evidence IV. Keywords Knee Injury Anterior cruciate ligament Meniscus Diagnosis Delay
Introduction Rupture of the anterior cruciate ligament (ACL) is a common injury [5]. The ‘typical’ pattern of injury commonly indicative of an ACL injury is a low-velocity twisting injury or valgus/external rotation strain; with or without an audible ‘pop’ or ‘snap’; with immediate pain and swelling (within 4 h) implying a haemarthrosis [3]. Within 1–2 weeks, a feeling of subjective improvement and recommencement of the ability to bear weight through the injured knee occurs. The patient often realizes that they have sustained a significant injury and often seek medical attention early (Fig. 1). Historically, the
123
Knee Surg Sports Traumatol Arthrosc
Fig. 1 Typical pattern of injury indicative of ACL rupture
accuracy of diagnosis has been poor despite many patients reporting a ‘typical’ injury pattern and having unequivocal physical signs [3]. At initial medical consultation, the rate of correctly diagnosing an ACL injury between 1980 and 2008 has varied from 6.8 to 25.9 %, respectively [3, 9, 11, 12, 17]. ACL ruptures and knee instability have been associated with an increased risk of developing secondary osteoarthritis [14]. The ability of ACL reconstructive surgery to prevent secondary osteoarthritis is still unknown; however, greater stability from reconstruction may be protective [4]. The delay in diagnosis of an ACL rupture increases the risk of secondary damage to the knee [6–8, 15, 20]. Failure of accurate diagnosis has obvious consequences for the patient who may require repeated medical consultations, attempt return to sports resulting in further damage to the knee and the associated economic burden of this. The primary aim of this study was to re-evaluate the accuracy of diagnosis of ACL ruptures at initial medical consultation with the hypothesis that this has not significantly changed over the last decade. The secondary aims were to determine the mechanism of injury (‘typical’ or ‘atypical’) and whether early diagnosis can minimize the risk of secondary damage to the knee.
Table 1 Mechanism of injury
Materials and methods
Statistical analysis
One hundred and thirty-two consecutive patients who underwent ACL reconstruction between 2005 and 2009 were analysed using prospectively collected data. The median age of the patients was 18 years (12–57). There were 78 (67 %) males and 38 (33 %) females. Sixteen patients were excluded due to chronic ACL injury (defined by delayed presentation following initial correct diagnosis being made and elected non-surgical management pursued) leaving 116 patients (117 knees) for inclusion in the study. Patients with other ligamentous injuries requiring surgical intervention were excluded. The mechanism of injury, associated activity, an audible ‘pop or snap’ and whether this fitted a ‘typical’ or
Statistical analysis was conducted using a paired t test (SPSS v19, SPSS Inc., Chicago, Illinois, and EXCEL, MicrosoftTM, WA). Significance was demonstrated by a p value B0.05.
123
Mechanism of injury
N (%)
Twisting
84 (72)
Direct blow
13 (11)
Hyperextension
5 (4)
Valgus/external rotation force
2 (2)
Not available
13 (11)
‘atypical’ injury pattern was recorded. The time period between injury and initial medical consultation and the accuracy of diagnosis were determined. The grade of medical practitioner was recorded at the initial medical consultation, and what diagnostic tests were used in order to diagnose an ACL rupture. The time interval between injury, accurate diagnosis and ACL reconstruction was also recorded. If patients had either received a magnetic resonance imaging (MRI) scan or undergone knee arthroscopy prior to ACL reconstruction, the findings were recorded and a comparison made to arthroscopic findings at the time of ACL reconstruction. At the time of ACL reconstruction, injury patterns including meniscal tears and chondral damage were recorded. Ethical approval was obtained from the London Surrey Borders Research Ethics Committee.
Results The mechanism of injury (Table 1) and associated activity recorded with injury was football (35 %), rugby (33 %) and skiing (10 %). An audible ‘pop or snap’ was recorded in 40 (34.2 %), not in 69 (60 %) and unknown in 8 (6.8 %) of cases. A ‘typical’ injury pattern was recorded in 87
Knee Surg Sports Traumatol Arthrosc
(74.4 %), ‘atypical’ in 27 (23.1 %) and unknown in 3 (2.6 %) of cases. The time to initial medical consultation following the injury was between immediate and 72 weeks Table 2 Diagnosis made at initial medical consultation following ACL rupture
4(3.4)
5(4.3)
Pivot shift
97 (82.9)
6(5.1)
14(12)
ACL rupture
33
No diagnosis
39
Positive (?ve) and negative (-ve) results of the Lachman and pivot shift test were recorded. In some cases, the tests could not be performed due to the patient not being able to tolerate them
Medial meniscal tear
12
Medial collateral ligament
12
Lateral collateral ligament
3 7 11
Patients (N)
Correct diagnosis (%)
58
12
Primary care physician Primary care physician and physiotherapist
16 4
19 25
Physiotherapist
11
36
4
50
Table 4 The clinical tests performed by the different grade of medical practitioner at time of initial medical consultation following injury. The mean time interval between injury and medical consultation and also the mean time to correct diagnosis of ACL injury is shown
Not possible N (%)
108 (92.3)
Emergency department practitioner
Orthopaedic consultant
-ve N (%)
Lachman
Table 3 Grade of medical practitioner at initial medical consultation and accuracy of diagnosis of ACL rupture
Ski resort doctor
?ve N (%)
Cases (N)
Not available
Orthopaedic resident
Test
Injury
Other
Grade
Table 5 The use of the Lachman and pivot shift tests in ACL deficient knees
11
73
7
100
(median = 0 weeks) and 79 (67.5 %) sought medical attention within 1 week of injury. The correct diagnosis of ACL rupture was made in 33 (28.2 %) of cases at initial consultation. If the diagnosis of an ACL rupture had not been made, the other diagnoses made at the initial medical consultation are shown in Table 2. The median number of medical consultations before the correct diagnosis of an ACL rupture was made in this series was 3 (1–6). The grade of medical practitioner and accuracy of diagnosing ACL rupture is shown in Table 3. The accuracy of diagnosis between the typical and atypical injury groups was 33.3 and 11.1 %, respectively (non-significant). Table 4 shows the clinical tests recorded by different medical practitioners, the time interval between injury and seeking medical attention and also the time interval from injury to diagnosis. Table 5 shows the use of the Lachman and pivot shift tests to correctly diagnose ACL rupture. The diagnosis was made in 13 (11.1 %) of cases with the use of MRI and 6 (5.1 %) cases at arthroscopy. In the cases where an MRI scan/arthroscopy was performed
Clinical test performed None documented Orthopaedic consultant (N = 7) Emergency department physician (N = 55)
Anterior drawer
Lachman
Pivot shift
Median time to 1st medical consultation (weeks, range)
Median time to diagnosis (weeks, range)
0
0
7
6
0 (0–4)
1 (0–4)
45
10
0
0
0 (0–8)
5 (0–156)
3
3
0
0
1 (0–4)
8 (1–20)
9
0
2
0
0 (0–52)
5 (1–20)
Primary care physician (N = 20)
17
0
3
0
5 (0–72)
20 (2–192)
Ski resort doctor (N = 11)
11
0
0
0
0 (0)
Emergency department (nurse practitioner), (N = 3) Physiotherapist (N = 11)
5 (0–32)
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Knee Surg Sports Traumatol Arthrosc Table 6 Associated injuries found at time of ACL reconstruction compared to time interval from injury Delay in diagnosis (months)
Medial meniscal tear (%)
Lateral meniscal tear (%)
Chondral injury (%)
0–4 (N = 52)
23.1
32.7
11.5
72.2
7.7
16.7
–
–
[6 (N = 18) p value
\0.05
before the ACL reconstruction, there were no significant differences between the MRI scan/arthroscopy findings and at the time of ACL reconstruction. The median time to diagnosis was 6 weeks (0–192), and the median time to ACL reconstruction was 24 weeks (1–240). Associated injuries recorded at the time of ACL reconstruction included medial meniscal tear (N = 46, 39.3 %), lateral meniscal tear (N = 36, 30.8 %) and chondral damage (N = 37, 31.6 %). The effect of timing of surgery on injury pattern identified is shown in Table 6.
Discussion The most important finding of the present study was that the mechanism of injury that results in rupture of the ACL often follows a ‘typical pattern’ and patients present with unequivocal physical signs, but despite this, the accuracy of diagnosis has been, and remains poor [3]. In this series, the accuracy of diagnosis was 28.2 % of cases at the initial medical consultation despite 74.4 % of patients describing a ‘typical’ injury pattern and 67.5 % seeking medical attention within a week following the injury. This supports the hypothesis that the accuracy of diagnosis has not significantly changed significantly in the last decade. The ‘typical’ injury pattern, which should prompt early referral to a knee specialist or for further investigation, includes reporting of points listed in Fig. 1. The median number of outpatient attendances leading to the correct diagnosis being made was 3 (1–6), which inevitably delays appropriate treatment. The delay in diagnosis has obvious consequences for the patient in terms of both sustaining secondary damage to the knee due to instability, socioeconomic burden and delay in return to work and also health economic cost savings. In the current economic, climate trying to deliver health care as efficiently as possible is an obvious priority. A recent study by Ball and Haddad has shown that an open access ‘Acute Knee Clinic’ can reduce the time interval to diagnosis of various soft tissue knee injuries and improve the efficiency of treatment with particular reference to ACL injuries [1]. The grade of medical practitioner who initially assesses patients with an acute ACL rupture will often be junior
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medical staff in the emergency department. The examination of an acutely injured knee is difficult due to pain and haemarthrosis. Performing specialist tests in order to accurately diagnose, an ACL rupture takes experience. The importance of the history is therefore paramount in making the diagnosis of an ACL rupture. Guillodo et al. [11] has shown that a substantial proportion of ACL ruptures were missed by emergency department doctors compared to sports physicians. In our study, the majority 89 (76.1 %) of patients were either first seen by an emergency department practitioner, primary care doctor or physiotherapist. The documentation of the special tests performed in order to ascertain ACL injuries was poorly recorded. However, where it was documented, the anterior drawer test was almost exclusively used by non-specialists. The poor diagnostic rate recorded in this study is multifactorial. Possible contributing factors to this may be a ‘lack of awareness’ or a low index of suspicion of the possible diagnosis. The difficulty with clinical examination, in the acute stage post injury, will improve over a few weeks and the reliance on further investigations in order to make the diagnosis. Rose and Gold reported that there was no significant difference in diagnostic accuracy between MRI and clinical examination performed by a knee specialist in complete ACL deficient knees [19]. Kocabey et al. [13] stated that, ‘a well trained, qualified surgeon can rely on clinical examination’ in order to diagnose an ACL rupture. The anterior drawer test is less useful in the acute ACL deficient knee (sensitivity 49 %, specificity 58 %) than the Lachman test, which is the most valid clinical test (sensitivity 85 %, specificity 94 %), and the pivot shift test, which is the most specific (98 %) but lacks sensitivity (24 %) [2]. In the outpatient clinic setting, the Lachman test has been shown to have the highest sensitivity for diagnosing an acute, complete ACL rupture but when the examination was performed under anaesthesia, the Lachman test still obtained the highest sensitivity, but the pivot shift test was the most specific illustrating the difficulty of performing the pivot shift test on an awake patient [21]. The Lachman and pivot shift test were possible to perform by an experienced orthopaedic surgeon in the majority of the cases in this study and were positive in 92.3 and 82.9 %, respectively. The Lachman and pivot shift tests could not be performed in 4.3 and 12 %, respectively, in the outpatient clinic due to pain. Church and Keating have shown that delays in reconstructive surgery of 12 months or greater increases the incidence of both meniscal tears and degenerative change compared to patients who have reconstructive surgery \12 months from injury [7]. O’Connor et al. [18] performed a retrospective analysis of 1,375 patients with an ACL rupture and the risk of meniscal injury and chondral damage increased with a delay of 6 months or more and 12 months or more, respectively. Sri-Ram et al. [20]
Knee Surg Sports Traumatol Arthrosc
reviewed 5,086 patients in order to determine the incidence of secondary pathology with respect to the time between injury and reconstruction and concluded that ideally, and particularly in younger patients, ACL reconstruction should not be delayed more than 5 months from injury. A similar time-dependent delay to reconstructive surgery has been shown to increase the incidence of secondary damage to the paediatric population also [16]. Frobell et al. [10] reported in young, active adults with acute ACL ruptures, a strategy of rehabilitation plus early ACL reconstruction was not superior to a strategy of rehabilitation plus optional delayed ACL reconstruction. Interestingly, the fact that the ACL rupture was diagnosed early and supervised rehabilitation initiated may explain the lack of secondary knee damage observed in this prospective randomized controlled trial. In this study, the incidence of meniscal injury and chondral damage appeared greater in patients having ACL reconstruction after 6 months following injury compared to those within 4 months following injury. This may be an indirect result of delay in diagnosis. Patients who are told that there is no significant knee injury will attempt return to activities that could result in further secondary damage to the knee. Interestingly, patients who underwent either an MRI scan or arthroscopy prior to ACL reconstruction were found not to have further meniscal or chondral damage to the knee. This supports the theory that interim activity modification between diagnosis and treatment may have an important role in preventing further knee damage. The limitations of this study were that only patients who had ACL reconstruction were included so there may be selection bias. The number of patients studied was small. Conclusions This study highlights that the diagnostic accuracy of ACL ruptures is still low. In order to improve this, the education of emergency department, primary care and physiotherapy practitioners may be beneficial in terms of recognizing the history of a ‘typical’ injury pattern. Improving diagnostic accuracy with the use of the Lachman and pivot shift test performed by non-specialists may not be successful as these tests can be difficult to perform in the acutely injured knee.
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