The Knee

Practical Questions

 

Can I rule-out fracture without radiographs?

There are probably 30 or more tests for the knee. Many seem to be minor variations on a theme. Which ones have been tested and shown to be of value?

Are there conservative approaches that work for knee problems? At what point do I refer?

Should I Order Radiographs?

That depends, of course, on the history. First, consider radiographs when ruling out fracture (if indicated from the history) using the Ottawa Guidelines:

Radiographs should be ordered after acute knee injury if any of the following are true:
• The patient is over the age of 55
• There is isolated tenderness at the patella
• There is isolated tenderness at the fibular head
• The patient is unable to flex the knee 90 degrees
• The patient is unable to bear weight immediately after the injury or take four steps in the emergency department

Stiell IG, Wells GA, Hoag RH et al. Implementation of the Ottawa Knee Rule for the use of radiography in acute knee injuries. JAMA 1997;278:2075-2079.

What tests should I perform?

Anterior Cruciate Tears

A meta-analysis by Benjaminse et al. agrees with past reviews that indicate that:

• The Lachman test has a pooled sensitivity of 85%; pooled specificity of 94%.
• The Pivot-Shift test is very specific with a pooled specificity of 98% but only 24% sensitivity
• The Anterior Drawer test is poor in acute settings but with chronic ACL conditions it has very good pooled sensitivity (92%) and specificity (91%)

Meniscus Tears

Shellbourne et al^. attempted to determine the correlation of joint line tenderness to meniscal lesions in patients with acute ACL tears determined by surgery.

• 51% of all patients had medial joint line tenderness (JLT) but only 45% had a medial meniscus tear

• 49% had no medial JLT but 35% of these had a medial meniscus tear

• 34% had lateral JLT and 58% had a lateral meniscus tear

• 66% had no lateral JLT but 49% had a lateral meniscus tear

• Medial JLT was 45% sensitive, 35% specific for a medial meniscus injury

• Lateral JLT was 58% sensitive and 49% specific for a lateral meniscus injury

This study suggests that joint line tenderness is often not likely to detect an associated meniscal tear with an acute ACL tear.

Benjaminse A, Gokeler A, van der Schans CP. Clinical diagnosis of an anterior cruciate ligament rupture: a meta-analysis. J Orthop Sports Phys Ther. May 2006;36(5):267-288.

Shelbourne KD, Martini DJ, McCarroll JR, VanMeter CD. Correlation of joint line tenderness and meniscal lesions in patients with acute anterior cruciate ligament tears. Am J Sports Med. Mar-Apr 1995;23(2):166-169.

 

Overall Accuracy of the Clinical Examination

Structures/Tests	Sensitivity	Specificity	LR for + Test	LR for - Test
ACL (Overall Exam)	82%	94%	25.0 (95% CI, 2.1-306.0)	0.04 (95% CI, 0.01-0.48)
Anterior Drawer	9%-93%; mean SD of 62%	Not reported	Not reported	Not reported
Lachmans	60%-100%; mean SD of 84%	Not reported	42.0 (95% CI, 2.7-651.0)	0.1 CI, 0.0-0.4)
Lateral pivot shift	27%-95%; mean SD of 38%	Not reported	Not reported	Not reported
PCL (Overall Exam)	91%	98%	21.0 (95% CI, 2.1-205.0)	0.05 (95% CI, 0.01-0.50)
Posterior Drawer	51%-86%; mean of 55%	Not reported	Not reported	Not reported
Meniscus (Overall Exam)	77%; SD of 7%	91%; SD of 3%	Not reported	Not reported
Joint line tenderness	79%; SD of 4%	15%; SD of 22%	0.9 (95% CI, 0.8-1.0)	1.1 (95% CI, 1.0-1.3)
McMurray	53%; SD of 15%	59%; SD 36%	Not reported	Not reported
Apley compression	16%	Not reported	Not reported	Not reported
Medial-lateral grind	69%	86%	Not reported	Not reported
Joint effusion	35%	100%	Not reported	Not reported

Legend: LR = likelihood ratio, SD = standard deviation, CI = confidence intervals, ACL = anterior cruciate ligament, PCL = posterior cruciate ligament, MCL = medial collateral ligament

LR for + test = sensitivity divided by 1 minus specificity

LR for – test = 1 minus sensitivity divided by specificity

Solomon DH, Simel DI, Bates DW, et al. Does this patient have a torn meniscus or ligament of the knee? Value of the physical examination. JAMA 2001;286:1610-1620.

 

Exercise for Management of Knee Disorders

Some basic principles for the use of exercise are as follows:

• Co-contraction isometrics are safe and effective initial exercises for hams & quads
• No exercise totally isolates the VMO (vastus medialis obliques); most isolation with medial rotation/extension
• VMO/VLO most active in terminal knee extension
• Open chain exercises are okay for patellofemoral problems; some risk for ACL deficient patients
• Closed chain exercises preferable for ACL-deficient patients
• Quad contraction is protective from 70 degrees of flexion through further flexion
• Bicycle riding - avoid too high of a seat for ACL and too low of a seat for PFA

Specifically, an eccentric program of rehabilitation for patellar tendinosis was found to be successful compared to a concentric program which left its participants seeking surgery or other approaches. The eccentric exercise group performed single-leg squats on a 25 degree decline board utilizing a typical Curwin-Stanish protocol of 3 sets, 10-15 repetition approach with moderate pain occurring in the last set. The downward or eccentric component was performed using the symptomatic leg with the upward or concentric component performed by the well-leg.

Jonsson P, Alfredson H. Superior results with eccentric compared to concentric quadriceps training in patients with jumper's knee: a prospective randomised study. Br J Sports Med. Nov 2005;39(11):847-850

Young MA, Cook JL, Purdam CR, Kiss ZS, Alfredson H. Eccentric decline squat protocol offers superior results at 12 months compared with traditional eccentric protocol for patellar

Manipulation for Knee Disorders

Most literature reports are small studies or case reports. Following are some interesting studies:

• SI manipulation may be of benefit for patients with anterior knee pain by decreasing muscle inhibition. A follow-up randomized controlled trial also confirmed an immediate effect on reducing knee extensor muscle inhibition.
• The results of a study by Moss et al. indicates that using accessory motion mobilization on osteoarthritic knees produces some immediate decreases in pain and a reduction in the “up and go” test for knee function.

Suter E, McMorland G, Herzog W, Bray R. Decrease in quadriceps inhibition after sacroiliac joint manipulation in patients with anterior knee pain. J Manipulative Physiol Ther. Mar-Apr 1999;22(3):149-153.

Suter E, McMorland G, Herzog W, Bray R. Conservative lower back treatment reduces inhibition in knee-extensor muscles: a randomized controlled trial. J Manipulative Physiol Ther. Feb 2000;23(2):76-80.

Moss P, Sluka K, Wright A. The initial effects of knee joint mobilization on osteoarthritic hyperalgesia. Man Ther. May 2007;12(2):109-118.

Surgery for OA and Osteochondritis

A Cochrane review evaluated the value of arthroscopic debridement for knee OA and found that there was no benefit especially over the long-term.

A study by Jurgensen et al. evaluated the rates of remission of arthroscopically versus non-surgical treated osteochondritis (as noted on MRI). They found partial or complete remission in 30% and no change in 63% of lesions managed non-surgically while with those treated arthoscopically there was remission in 37% and no change in 57%.


Laupattarakasem W, Laopaiboon M, Laupattarakasem P, Sumananont C. Arthroscopic debridement for knee osteoarthritis. Cochrane Database Syst Rev. 2008(1):CD005118.

Jurgensen I, Bachmann G, Schleicher I, Haas H. Arthroscopic versus conservative treatment of osteochondritis dissecans of the knee: value of magnetic resonance imaging in therapy planning and follow-up. Arthroscopy. Apr 2002;18(4):378-386.