Prospective evaluation of the McMurray test PETER J. EVANS,*† MD, PhD, G. DOUGLAS BELL,‡ MD, FRCS(C), AND CY FRANK,‡ MD, FRCS(C)

From the ‡Division of Orthopaedic Surgery and Sport Medicine Centre,University of Calgary, Calgary, Alberta, and the *Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada

ABSTRACT accurate means of diagnosing meniscal injury; however, in their comparisons with clinical diagnoses, they did not com- The and interexaminer of the Mc- accuracy reliability ment on the McMurray test specifically.4,5,9 test for the of meniscal tears were Murray diagnosis In a prospective study in 1980, Noble and Erat12 found with in a compared arthroscopic findings prospective that the McMurray test was positive in 62.1% of vertical or of 104 consecutive elective study patients awaiting tears, in 63% of horizontal tears, and in 41.7% of The found oblique arthroscopy. only significant McMurray sign normal menisci. They noted the &dquo;absence of any reliable to correlate with meniscal was a "thud" elicited injury clinical pattern differentiating between the patients with a on the medial line with a medial meniscal tear joint torn and those without. 1112 = that had a fair interexaminer (P 0.05) reliability (kappa Medlar et al.11 and Barry et a1.3 found that the McMurray = 0.35). The sensitivity of a medial thud was 16%, and test was positive in only 45% to 50% of patients with a the was 98% with a positive predictive value specificity suspected meniscal tear. In 1986, Anderson and Lipscomb’ of 83%. Examiner experience had little effect on the reported on 100 patients with suspected meniscal tears accuracy of diagnosis of medial meniscal tears. This scheduled A test was the continued but limited on undergoing arthroscopy. McMurray study supports emphasis in 58% and in the McMurray test in the clinical diagnosis of meniscal positive false-negative 38%. False-negatives tears. were attributed to locked and to those with flexion limited by pain. Collectively, these reports suggest a low sensitivity and for the but to date no of T. P. Mcmurray&dquo; described a test for meniscal tears of the specificity McMurray test, analysis in his lecture, entitled &dquo;The Semilunar Cartilages,&dquo; to the interobserver reliability has been performed. the Royal College of Surgeons of England in 1940. Since The method of performing the McMurray test has been revised some most As that time, the McMurray test has been used as one of the by authors, notably Hoppenfeld.’ primary diagnostic tests in the surgical decision-making originally described by Mcmurray,&dquo; the &dquo;simplest routine is to the flexion to a process for meniscal tears. bring leg from its position of acute right The validity of the McMurray test and its modifications angle, whilst the foot is retained first in full internal, and then in full To the have been questioned previously. Many articles have as- external rotation.&dquo; examine right knee, sessed the accuracy of a clinical diagnosis of meniscal tears. the left hand is placed on the knee with the thumb over the Apley2 reported on his test for meniscal tears using the lateral joint line and with the first and second fingers over prone position with knee joint compression or distraction the medial joint line while the right hand maintains the with rotation. Apley compared the results of this &dquo;grind test&dquo; rotation of the tibia. The opposite is true for the left leg. and &dquo;distraction test&dquo; with &dquo;orthodox methods&dquo; that in- Note that at no time is a valgus or varus stress applied to cluded the McMurray test. His test was shown to be useful the knee. when false-negative orthodox methods were obtained, but McMurray described a &dquo;thud,&dquo; palpable and produced by he did not specify his statistical methods of comparison. the loose fragment of meniscus caught between the femur Jackson and Abe,9 DeHaven and Collins,’ Daniel et a1.,4 and tibia during rotation. He also noted a &dquo;sensation&dquo; that and others7,14,15 have reported that arthroscopy is the most was described by patients as reproducing their clinical symp- toms. McMurray stated that most medial meniscal tears could be detected a thud or sensation t Address correspondence and repnnt requests to: Peter J. Evans, MD, 262 by eliciting during Wobum Avenue, Toronto, Ontano, Canada, M5M 1 K9 manipulation of the knee in external rotation from full 604 605 flexion to 90°. Conversely, lateral meniscal tears could be our series; however, we did not consider the test as being detected by eliciting a thud or sensation during manipulation positive with pain alone. of the knee in internal rotation from flexion to 90°/° The operative group underwent arthroscopic surgery by McMurray also stated that by &dquo;altering the position of one surgeon (GDB) and the type (longitudinal, horizontal, flexion of the joint the whole of the posterior segment of the and radial) and position (posterior third, posterior two cartilages can be examined from the middle of their posterior thirds, anterior two thirds, and anterior third) of a tear were attachments.&dquo; The degree of flexion was thought to correlate recorded. These findings were then compared with the pre- with the position of the tear in the anterior-posterior plane. operative McMurray test findings. Extending the knee beyond 90° to look for signs of tears in the anterior of the was believed to be segment cartilages Statistical inaccurate. analysis The of this was purpose study to determine prospectively Analysis of the McMurray test was done by a two-tailed the and sensitivity specificity of the McMurray test in analysis using the chi-square test (with the Yates’ correc- predicting and localizing meniscal tears, as well as to deter- tion) and the Fisher’s exact test, where appropriate. The mine its interexaminer reliability, using arthroscopic diag- interexaminer reliability was analyzed by the kappa test.13 nosis as the designated standard. The frequency of a positive The clinical findings of thud and sensation were first com- test in apparent normal controls was also studied. pared with arthroscopic findings for each examiner. Subse- quently, only when both examiners elicited a positive sign was this considered to be a and was com- MATERIALS AND METHODS positive finding pared with meniscal injury. Only when both did not elicit a sign was the finding considered to be negative. From this Patient selection second analysis, the overall accuracy of the test was derived. Two populations were studied. The first population (normal controls) consisted of 60 medical students who did not RESULTS undergo arthroscopic surgery, giving a total of 120 knees examined. Of these 120 knees examined, 25 knees with Control results previous injuries were eliminated from the study. Ninety- five knees had no history of a previous injury and had no Of the assumed normal knees, five knees were found to have symptoms present at the time of examination. a positive McMurray sign by only one examiner (PJE) and The second population consisted of 104 consecutive pa- eight knees by only the second examiner (GDB). Only three tients awaiting elective arthroscopic surgery, giving a total knees were found to have a positive McMurray sign by both of 104 knees examined. All patients had been booked for examiners. arthroscopy for a variety of reasons based on a previous history and examination. Conditions other than physical Arthroscopy results just the suspected meniscal tears were included for insight into the true sensitivity and specificity of the test in symp- In the 104 knees undergoing arthroscopy, meniscal injury tomatic . was found in 59 patients (56%), and it was localized to the medial meniscus in 47 (80%), and to the lateral meniscus in 12 (20%). Some menisci had tears Patient examination and surgery multiple present, making a total of 69 individual tears. The types of tears on the Each patient had a McMurray test that was performed medial meniscus included 81% longitudinal, 7% radial, and independently by two examiners before a repeat history was 11 % horizontal tears, while on the lateral meniscus these taken on admission to eliminate the influence of the history were 33%, 47%, and 20%, respectively. on the interpretation of each test. Examiners included the senior author (GDB), who has been in clinical practice for McMurray test for detection of actual tear sites 10 years, and a medical student (PJE), who was taught the McMurray test specifically and who had ample opportunity Of the 69 tears, the site was localized arthroscopically to the before this investigation to practice it according to Mc- posterior third in 29 cases (42%), spanning the posterior two Murray’s descriptions. thirds in 27 cases (39%), the middle third alone in 9 cases In this study, therefore, each knee was assessed by both (13%), spanning the anterior two thirds in 3 cases (4%), and examiners in the fashion originally described by McMurray. the anterior alone in 1 case. Similarly, 92% of the McMurray If a thud or a sensation was elicited, it was recorded accord- signs were elicited predominantly from the posterior seg- ing to side, degree of flexion, and direction of rotation of the ment (full flexion to 120°), while only 6% were in the middle tibia. segment (60° to 120° of flexion), and 2% were in the anterior While pain is not part of the McMurray sign, it has been segment (0° to 60° of flexion). This indicates that most commonly interpreted as part of meniscal testing,’ and McMurray signs and actual injuries occurred at the posterior hence its production by the maneuver was also recorded in portion of the meniscus. 606

McMurray test results lateral joint line. The degree of agreement for sensation was poor on both joint lines and fair for pain on both joint lines. Of the 104 knees having subsequent arthroscopy, there were Table 3 demonstrates the effect that clinical experience has 51 with a either positive McMurray sign (either sign, side, on the accuracy of diagnosing medial meniscal tears with either examiner), 46 with a positive McMurray thud, 29 with the McMurray test. A medial thud elicited by the McMurray a and 24 with both sensation, signs present (either side, maneuver was associated significantly with medial meniscal either examiner); 9 had a positive McMurray test by 1 tears by the less experienced examiner only, whereas medial examiner alone 20 the second examiner alone (GDB), by sensation and pain were associated significantly with medial (PJE), and 20 by both examiners. meniscal tears by the experienced examiner only. Which is best? Tables 1 and 2 demonstrate the sign degree Accuracy of the McMurray test. The clinical accuracy of of association between a thud or sensation and a eliciting the McMurray test was assessed only for a medial joint line tear on either the medial or lateral meniscus. With the knee thud because sensation on both joint lines and thud on the in the rotated a thud elicited on externally position, only lateral joint line were not significant. Table 4 illustrates that was with medial the medial joint line associated significantly when a medial thud is elicited the likelihood afterward of meniscal tears = Table With the knee in the (P 0.05; 1). the presence of a medial meniscal tear is 83% (positive rotated a lateral thud was not associated internally position, predictive value); however, when a medial meniscal tear was with lateral meniscal Sensa- significantly injury (Table 2). present a medial thud was elicited only 16% of the time tion was not on either line. significant joint (sensitivity). When a medial thud was not present, the Rotation and described the detec- laterality. McMurrayl0 likelihood afterward of the presence of a medial meniscal tion of medial tears medial line with the tibia by joint signs tear was 65% (negative predictive value). When no medial rotated as we have externally presented (Table 1); however, tear was present, no medial thud was elicited (specificity) no mention was made of other possibilities. In this study, 98% of the time. the signs elicited on the lateral joint line with the tibia externally rotated were too few to be associated significantly. Similarly, with the tibia internally rotated, neither medial nor lateral joint line signs were significantly associated with DISCUSSION medial tears (data not shown). McMurray detected lateral tears by lateral joint line signs elicited with the tibia inter- This is the first study to correlate prospectively and system- the medial and lateral line elicited the nally rotated. In the current study, this association was not atically joint signs by shown (Table 2). In addition, significant association between McMurray maneuver with meniscal injury and determine the interexaminer of the test. The of the medial joint line signs and lateral tears when the tibia was reliability findings the continued but limited held and internally rotated was not found. Similarly, with present study support emphasis on the test in the clinical of meniscal the tibia externally rotated, neither medial nor lateral signs McMurray diagnosis tears. Examination of our of 95 normal knees revealed were significantly associated with lateral tears (data not group shown). only 3 cases that both examiners agreed had a positive test. Particular concern would be re- Interexaminer reliability. The reliability between exam- McMurray expressed iners using the McMurray test is shown in Tables 1 and 2. garding the McMurray test if false-positive findings of The kappa test consists of six levels of agreement, ranging TABLE 3 in from poor to almost perfect. The degree of agreement Effect of examiner experience on diagnosis of medial meniscus detecting a thud was fair on the medial and slight on the injury&dquo;

TABLE 1 Signs elicited in external rotation with medial meniscus injury&dquo;

° Includes horizontal, longitudinal, and radial tears.

° Includes horizontal, longitudinal, and radial tears. TABLE 4 Accuracy of medial thud elicited in external rotation and lateral pain elicited in internal rotation TABLE 2 Signs elicited in internal rotation with lateral meniscus injury&dquo;

° Includes horizontal, longitudinal, and radial tears. 607 greater than 3% to 4% in normal knees had been found. We the sensitivity was very low (16%). Therefore, a torn medial believe that this is the lst report of the McMurray test in meniscus would be missed in many patients if one solely knees deemed normal by history-normal being a negative relied on the McMurray test. We found a lower sensitivity history of injury or symptoms or any other pathologic signs. (16%) than other reports in the literature, likely because our The 3 positive McMurray tests found may have been a result patient entry criteria included patients with various knee of a hypermobile but normal meniscus, an asymptomatic complaints, not just those with suspected or proven meniscal torn meniscus, or some other asymptomatic problem. tears as in most other studies. We believe this more fairly Noble and Erat12 statistically analyzed a myriad of symp- represents the use of the McMurray test in its clinical role toms and signs, including the McMurray test, and were of aiding in the diagnosis of meniscal tears in patients with unable to find a reliable way of clinically diagnosing meniscal knee complaints. Importantly, the specificity of the test was tears. They reported a 62.1% incidence of a positive Mc- high (98%), which indicates that false-negative signs from Murray sign in patients with a vertical or oblique tear, a other injuries of the knee, such as synovial plica, osteochon- 63% incidence in patients with a horizontal cleavage tear, dral articular flaps, inflammatory popliteal tendinitis, loose and a 41.7% incidence in patients with normal menisci at bodies, or clunks associated with iliopsoas or iliotibial band the time of surgery. Barry et al.3 looked at many signs and snapping, rarely occurred. symptoms as well as radiographic findings and preopera- Like many other examination techniques, the McMurray tively allocated patients into either a definitive or dubious test is quite subjective. The interexaminer reliability of tear group. They found a 40% incidence of a positive medial thud was only fair (kappa = 0.35), demonstrating the McMurray sign in their definite tear group, all of whom had low level of agreement between the two examiners. In addi- a tear present at surgery. The dubious tear group had a 28% tion, examiner experience did not have an effect as evidenced a but incidence of positive McMurray sign preoperatively, by the fact that only the less experienced examiner accu- only 7 had a tear present at surgery. Barry et al. did not rately diagnosed medial meniscal tears by eliciting a medial evaluate the of the statistically predictive power McMurray thud. It is of interest that the more experienced examiner test. Medlar et ail.&dquo; a of a reported preoperative finding accurately diagnosed medial meniscal tears by eliciting a in 11 of 26 children who underwent positive McMurray sign sensation and pain with the McMurray maneuver, again meniscectomy, but they did not comment on its accuracy in emphasizing the subjective nature of the test. It is possible the 15 tears found at predicting surgery. that the amount of force applied with the McMurray ma- Anderson and of a new Lipscomb’ compared the accuracy neuver may influence the pain and sensation response elic- medial-lateral grind test with the accuracy of the McMurray ited, thus further emphasizing the subjectiveness of the test. test. Of 100 examined patients preoperatively, they reported At best, the McMurray test will aid in the diagnosis of a a high yield of 93 meniscal tears found at arthroscopy. They medial meniscal tear, but, in view of the low sensitivity and found the McMurray test to be positive in 58%, and there fair interexaminer reliability of the test, it cannot be consid- were 5 and 38 There was no false-positives false-negatives. ered as the diagnostic standard in the decision for arthrot- statistical measure of the degree of association between the omy or arthroscopy. McMurray test and meniscal tears, nor was there any meas- Despite ever-increasing sophistication of noninvasive and ure of the of the test. In a recent predictive power prospective invasive diagnostic procedures, re- Fowler and the test was study by Lubiner,’ McMurray mains the first important test for a patient. We hope that demonstrated to have a of 28.8% and a sensitivity specificity the improved knowledge of the McMurray test’s accuracy of and to be correlated with a of 95.3%, negatively diagnosis will assist in putting physical examination on a more sci- chondromalacia patella. Unfortunately, there was no break- entific basis. Many other commonly used physical diagnostic down as to the test accuracy in diagnosing medial versus tests should be similarly evaluated. lateral tears. This study has demonstrated that the McMurray test was not useful in lateral meniscal tears. diagnosing Although REFERENCES lateral joint line pain that was elicited using the McMurray maneuver in internal rotation was associated significantly 1.Anderson AF, Lipscomb AB: Clinical diagnosis of meniscal tears. Descrip- with lateral meniscal tears (P = 0.03; Table 2), the positive tion of a new manipulative test. Am J Sports Med 14: 291-293, 1986 2 AG. The of meniscus J Bone Joint 29: 78- value was 29% (Table 4). This indicates that Apley diagnosis injuries. Surg predictive only 84,1947 pain is reproducible in but not predictive of meniscal injury. 3. Barry OCD, Smith H, McManus F, et al. 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