Based on science. Works like magic.

Abundant Medical Literature – A Review

Medical literature shows that even the most expert surgeons are not perfect in their clinical diagnoses.1-6 It is also reported that use of various single physical exam tests will not produce 100% clinical accuracy.7,8 Even extensive physical examination findings for a single diagnosis were not very accurate.9 It may be surprising to learn that even the very sensitive MRI may not be better than the surgeon’s clinical impression.10,11It’s also important to note that it’s rare that there is only one problem in the knee. For instance, the patient may have an injury that resulted not only in a torn cartilage, but a torn ligament. If there were previous injuries, then arthritis of variable magnitude would complicate the issue.12  So taking multiple factors into consideration is more accurate in determining a diagnosis.13


Traditionally, the diagnostic process is initiated with a physician taking a medical history by questioning and examining the patient. The physician forms what is called a clinical impression following the initial patient encounter. The clinical impression is speculative. The physician then selects one or more additional tests to better define the diagnosis. He/she must choose the tests that have the greatest predictive value for any given patient’s condition. This again requires judgment since predictive values of various tests are either not known or provide little direction.9

Human Error…

X-rays, arthrogram (dye injection into the joint), CAT scans, bone scans, and more recently MRI – all of these diagnostic methods are subject to human error, equipment failure and/or misinterpretation. Inaccuracy may accompany every method. For instance, the patient may not be an accurate historian. They may forget or even withhold information. The physician may not ask a uniform set of questions, let alone knowing whether the questions have predictive value. The physician often relies only on anecdotal evidence based upon experience or lack thereof.

Laboratory tests are subject to interpretation. The imaging documents are subject to human error in creation or by interpretation. Even arthroscopy providing for direct inspection of the joint may be limited by the physician’s technical ability or instrumentation. There can be many factors that lead to uncertainty in making a diagnosis and the subsequent treatment plan.

It is apparent that new means of determining the diagnosis would be welcome. Hence, the introduction of

The information age brings such a new and powerful tool to assist in making a knee joint diagnosis. It is based upon the power of data. Utilizing massive databases from clinical practices, it is now possible to select questions that have scientifically established predictive power to make a diagnosis.14 The differentiation was possible in that a comparison could be made to a cohort of men and women who had always considered their knees normal.15 A random set of patients in the database was used in the analysis. The remaining patients were used to validate the method and establish the reliability. The method was further validated by applying it to similar databases from other surgeons. This is all accomplished by computer computation.

Customized Reports Developed By True Experts

Unlike most Internet site diagnostic methods that provide general information, provides a personalized report concerning your knee problem. This is accomplished by assessing your responses to a set of uniform questions, each selected for its predictive value in determining a known knee joint diagnosis. For your convenience we offer links to Internet sites with general information on knee problems. was developed by Information Health Network—a small medical software research and development company founded by Lanny L. Johnson, MD, of East Lansing, Michigan, in 1982. Dr. Johnson, a pioneer in arthroscopic surgery, initially developed a proprietary computerized medical record to better communicate with his patients and to facilitate his clinical research. Andrew W. Pittsley, an electrical engineer by training, has been the Chief Software Architect. Information Health Network’s software and various information systems facilitated the development of an extensive clinical database unlikely to exist elsewhere. This database provided the material for many scientific publications, some of which are listed under References.

A young woman massaging her painful knee

A young woman massaging her painful knee

In a 1996 pilot study based on the database, the authors confirmed their hypothesis that a differential diagnosis could be made from medical history data alone.14 An analysis was made of the data to select the fewest possible questions with strong predictive value that would produce consistently reliable results for making a differential diagnosis of a knee problem.14


The following scientific publications serve as background for comparing this new diagnostic instrument,, with reports in the medical literature on the accuracy of the orthopedic surgeons’ opinions as well as reports on MRI evaluations for determining the cause of knee problems.

1. Impact of diagnostic arthroscopy on the clinical judgment of an experienced arthroscopist
Johnson LL.
Clin Orthop Relat Res 1982; 167:75-83.

This article pointed out the diagnostic accuracy of one experienced surgeon in 1000 consecutive knee patients. Patients underwent a verbal medical history interview, a physician’s physical examination, and plain film x-rays.

As shown in Table 3 in the article, the surgeon’s clinical diagnosis was correct in 21% of patients. The diagnosis listed by the surgeon was found, but was not the primary diagnosis, in an additional 23% of patients, for a total of 44% reliability. In other words, the clinical diagnosis was wrong in 56% of patients. It should be noted that the method of choosing only one preoperative diagnosis adversely affects diagnostic accuracy, which still reached only 44% with secondary diagnoses being considered. Ironically, the clinical method used in this report had a 70% accuracy rate for torn lateral meniscus, whereas the data and software are not able to diagnose torn lateral meniscus.

One of the conclusions reached in this study was that because there are often multiple lesions in the knee, it is difficult to make a single correct diagnosis. Another observation was that the surgeon’s diagnostic accuracy varied with the nature of the problem. It was high when no findings were anticipated and low for the common torn medial meniscus.

2. Diagnosis of internal derangements of the knee
DeHaven KE, Collins HR.
J Bone Joint Surg 1975; 57A:802-810.

This prospective study used physician interviews, physical examination, and plain film x-rays for the evaluation. Accuracy was determined to be 72%, partial accuracy 10%, and inaccuracy 18%.

3. The accuracy of the clinical examination documented by arthroscopy
Oberlander MA, Shalvoy RM, Hughston JC.
Am J Sports Med 1993; 21:773-778.

In this report of 306 knee patients, the correct diagnosis was made in only 56% of patients; the diagnosis was incomplete in 31%. With multiple lesions in the knee, the percentage of accuracy dropped to 30%.

Multiple surgeons participated in the study, which affects uniformity even with pre- and postoperative forms. MRI and arthrogram, which were performed on some patients, can be assumed to have increased accuracy. It was not clear whether a single clinical diagnosis or lead diagnosis was used as the benchmark. If this method was used, it would lower the rate of accuracy.

4. Reliability of the clinical assessment in predicting the cause of internal derangements of the knee
Terry GC, Tagert BE, Young MJ.
Arthroscopy 1995; 11:568-576.

In this report of 206 knee patients, the senior author’s diagnosis was correct in 81% of patients. Rate of accuracy was highest for torn medial meniscus (85%) and lowest for torn lateral meniscus (58%).

Predictive accuracy was increased by the use of multiple diagnoses in this study—with surgeons calling themselves correct if one of their predictions was present. The study included use of clinical examination and x-rays.

5. The diagnostic accuracy of history, physical examination, and radiographs in the evaluation of traumatic knee disorders
O’Shea KJ, Murphy KP, Heekin RD, Herzwurm PJ.
Am J Sports Med 1996; 24:164-167.

The authors reported on 156 military personnel who were examined and x-rayed. Their method included making a single primary diagnosis related to the patient’s chief complaint, and a secondary diagnosis that could exist with the primary diagnosis. A secondary diagnosis was not made in all patients. There were three surgeons with one to three years of practice experience. They were 83% correct on the primary diagnosis and 54% correct on the secondary diagnosis. They compared their results with those of others who used MRI and concluded that routine use of MRI to diagnose knee problems is probably not indicated.

6. Accuracy of clinical diagnosis in Knee Arthroscopy
Brooks S, Morgan M.
Ann R Coll Surg Engl. 2002 (84):265-268.

7. A review of the McMurray test: definition, interpretation and clinical usefulness
Stratford PW, Binkley J.
J Orthop Sports Phys Ther. 1995 Sep;22(3):116-20.

This report compares one specific diagnostic physical exam test with the likelihood or unlikelihood of the suspected diagnosis by medical history. It points out the importance of balancing the clinical impression from the medical history with the extent of the physical examination. It would appear that the impression gained from the medical history information did not have any predictive value, perhaps due to the questions asked or the thought process of the physician.

8. Diagnostic accuracy of a new clinical test (the Thessaly Test) for early detection of meniscal tears
Karachalios T, Hantes M, Zibis AH, Zachos V, Karantanas AH, Malizos KN.
J Bone Joint Surg 2005;87A:955-962.

The authors report a single physical exam test has 94% diagnostic accuracy for a single knee joint condition, torn medial meniscus. However, as valuable as this test might be, the conditions are often multiple and their was not consideration given to the diagnostic accuracy of a torn meniscus in presence of a torn anterior cruciate ligament or degenerative arthritis.

9. The accuracy of physical diagnostic tests for assessing meniscal lesions of the knee: a meta-analysis
Scholten RJ, Deville WL, Opstelten W, et al.
J Fam Pract 2001;50:938-44.

After a review of 13 studies in the literature with total of 2231 patients, the authors concluded that physical examination tests and findings had low diagnostic accuracy for making diagnosis of meniscal lesions of the knee when compared to the evidence seen at arthroscopy or MRI.

This report illustrates that traditional physical examination observations like joint tenderness or swelling or physical examination findings of a positive McMurray alone are not predictive of a torn meniscus.

10. Correlation of Arthroscopic and clinical examinations with magnetic resonance imaging findings of injured knees in children and adolescents
Stanitski CL.
Am J Sports Med. 1998;26:2-6.

This report evaluated the correlation among clinical diagnosis (really impression), magnetic resonance imaging reports, and arthroscopic findings in 28 patients, aged 8 to 17 years. The conclusion was that the clinical impression of the experienced surgeon was more accurate, greater positive predictive value, better negative predictive value, more sensitive, and more specific than that gained from the MRI reports. Overall, magnetic resonance imaging diagnoses added little guidance to patient management and at time provide spurious information.

The emphasis herein was upon the strength of this experienced surgeon’s use of the MRI in patient management.

11. Accuracy of clinical diagnosis in knee arthroscopy
Brooks S, Morgan M.
Ann R. Coll Surg Engl. 2002;84(4):265-268.

The authors compared clinical impression of 9 different orthopedic consultants with MRI for diagnostic accuracy. They used the arthroscopic findings as the benchmark for the definitive diagnosis. They report that in 238 patients that their clinical impression (79%) was as accurate as MRI(77%), but neither perfect alone. Unfortunately, no factors were reported that assisted in formulating the clinical impressions.

12. A prospective study of the accuracy of clinical examination evaluated by arthroscopy of the knee
Yoon YS, Rah JH, Park HJ.
International Orthopaedics. 1997;21(4):223-227.

The clinical diagnosis was correct in 52%, incomplete in 35%, and incorrect in 13%. When more than 3 lesions were discovered, the accuracy was 28%. The results were independent of age, sex, MRI and the surgeon who was evaluating.

This report points up the difficulty in ascertaining an exact knee joint diagnosis, especially when there are multiple lesions. Multiple lesions is most often the case.

13. Does this patient have a torn meniscus or ligament of the Knee?
Solomon DH, Simel DL, Bates DW, Katz JN, Schaffer JL.
JAMA 2001;286(13):1610-1620.

The authors reviewed the literature to evaluate what information most likely would make a correct diagnosis between a torn meniscus and a torn anterior cruciate ligament in the knee. They concluded that the composite examination for specific meniscal or ligamentous injuries of the knee performed much better than specific maneuvers. They suggested that the synthesis of a group of examination maneuvers and medical historical evidence may be required for an adequate diagnosis.

Their wording, including “suggested” and “may”, were typical of such reports, but the use is also not helpful in coming to a definitive clinical judgment. Their report did support the necessity that multiple of data points are imperative to correct conclusions.

14. Is it possible to make an accurate diagnosis based only on a medical history? A pilot study on women’s knee joints
Johnson LL, Johnson AL, Colquitt JA, Simmering MJ, Pittsley AW.
Arthroscopy 1996; 12:709-714.

This pilot study demonstrated 98% accuracy with 100 questions and 85% accuracy with 30 questions in making a differential diagnosis. It also demonstrated that the medical history factors with statistical predictive value are not those typically chosen by experts or consensus panels. This article was the inspiration to take the method further for all diagnoses of the knee, hence

15. Clinical assessment of asymptomatic knees: Comparison of men and women
Johnson LL, van Dyk GE, Green JR, Pittsley AW, Bays B, Gully SM, Phillips JM.
Arthroscopy 1998; 14:347-359.

This report demonstrated that there are many common clinical findings in people with “normal” knees that otherwise would be considered surgical indications. In addition there was a gender difference in findings. Some of the differences were unexpected (e.g. the men had higher measured lateral patellar position than women). This report identified a list of common surgical indications that exist in otherwise normal people. It also provided data to identify pathologic findings, which are never found in “normals” (bottom right on page 357 of the publication).

16. MRI efficacy in diagnosing internal lesions of the knee: a retrospective analysis
Vassilios S Nikolaou, Efstathios Chronopoulos, Christianna Savvidou, Spyros Plessas, Peter Giannoudis, Nicolas Efstathopoulos, Georgios Papachristou
Journal of Trauma Management & Outcomes 2008, 2:4 (2 June 2008)

Note: The report is intended to be used in consultation with your physician’s judgment in determining diagnostic and/or treatment options using all the potential available means.