Stanitski CL. Correlation of Arthroscopic and Clinical Examinations with Magnetic Resonance Imaging Findings of Injured Knees in Children and Adolescents. Am J Sports Med 1998, 26:1;2-6.
As previously reported in other studies comparing clinical examination of the knee, MRI, and arthroscopic evaluation, it appears that the clinical examination is often underestimated in its ability to detect significant injury. This article follows on the heels of other articles that demonstrate how our love affair with advanced technology has caused us to mistrust our own human skills. Yet in the advancing wave of managed care, a search for cost-effectiveness has led to a reappraisal of the value of the clinical examination.
What is unique about this small study is that it uses a child/adolescent population. The results indicate that the positive correlation between clinical exam and arthroscopic findings was 78.5 percent. When judging the positive predictive value for ACL or meniscal injuries, the clinical exam value as 96.2 percent, and the negative predictive value was 93.3 percent. Compare this to the MRI values, which had a positive predictive value of 71.4 percent, and a negative predictive value of 72.4 percent. Although a small study, it supports previous studies that suggest a premature referral for MRI may result in no added diagnostic value beyond the clinical exam, but will increase health care costs.
Demirdjian AM, Petrie SG, Guanche CA, Thomas KA. The Outcomes of Two Knee Scoring Questionnaires in a Normal Population. Am J Sports Med 1998, 26:1;46-51.
Today's focus on outcome-based research and patient management has led to the use of a plethora of questionnaires, both as screening tools and measurements of functional outcome following rehabilitation or surgery. Many decisions regarding the best management of a condition are based on these tools if they have been rigorously tested for reliability and validity. Yet it appears that many questionnaires that are in common use have never passed the obvious test. Can a patient with no problem or complaint in the area being evaluated score a perfect score?
If a patient has no knee complaint, has had no prior significant trauma, and is young and athletic, would they attain a perfect score on a questionnaire that is attempting to measure functional limitations in patients with knee problems? It appears not! Using two commonly employed knee questionnaires (Noyes and Lysholm), the researchers screened over 400 young athletes who had no knee complaints or past history of knee problems. Although they all scored high, no one scored a perfect 100. Additionally, the female athletes, on average, scored lower than males. The researchers suggest that these questionnaires need to be modified to identify "normal" asymptomatic knees first; if not, the scores for postsurgical or postrehabilitation patients will be artificially lower due to the flaw in the instrument's design.
Fleming BC, Beynnon BD, Renstrom PA, et al. The Strain Behavior of the Anterior Cruciate Ligament During Bicycling. Am J Sports Med 1998, 26:1;109-118.
Bicycle riding is often prescribed as an early rehabilitation strategy with many knee problems, or after surgery. Past studies indicate that too low a seat may aggravate patellar problems, and too high a seat may adversely affect ACL deficient knees. This current study attempted to determine whether changes in power or cadence affect the strain on the ACL (in patients with normal ACLs). A transducer was surgically applied to the anteromedial bundle of the ACL in a group of patients. Different power levels (75, 125 and 175 W) and cadences (60 and 90 rpm) were used.
There appears to be no difference in strain on the ACL with any of the above variables. This is important information when prescribing bicycle exercises for ACL-deficient patients. It generally means that there are enough compensations made muscularly to negate any effects from an increase in power or cadence. During the pedaling cycle, past studies have indicated that the quadriceps are most active when the knee is flexed. This would cause more of a posteriorly directed force to the tibia. Also, hamstring activity is strong throughout the remainder of the crank cycle, providing a strong posterior force reducing strain on the ACL. ACL strain appeared to be greatest between about 120 to 200 degrees (0 degrees with pedal at top; 180 degrees with pedal at bottom). Interestingly, this correlates with a high EMG activity for the gastrocnemius muscles. As the attachment of the gastrocnemius is on the femur, an anteriorly directed force may occur with contraction.
McMaster WC, Roberts A, Stoddard T. A Correlation Between Shoulder Laxity and Interfering Pain in Competitive Swimmers. Am J Sports Med 1998, 26:1;83-86.
Forty athletes who met the criteria for U.S. Swimming Senior National time standards (some previous Olympians) were evaluated. A questionnaire was used to determine if pain interfered with their performance. They were clinically evaluated for shoulder laxity using the sulcus sign, and anterior and posterior provocation tests (apprehension tests) in the seated and recumbent position. There was a strong correlation between clinical evidence of laxity and pain interference with performance. The authors suggest that there is a spectrum of normal shoulder laxity. At some point, this physiologic laxity may become clinically unstable, producing pain with provocative maneuvers. The authors caution swimmers, their trainers and doctors to critically examine how much passive stretching should be done with the shoulder (especially if uncomfortable); avoid the use of hand paddles; and avoid the use of heavy resistance overhead weight training. During periods of pain, the recommendation is to increase body roll, maintain a high elbow at recovery, and avoid excessive elbow extension prior to the hand insweep portion of the stroke. Emphasis on rotator cuff training is again recommended.
Thomas Souza, DC, DACBSP
San Jose, California
arrwes-aol.com