Anatomy

Meniscus.jpg
The knee joint is comprised of four bones the femur, tibia, fibula and patella. The joint also contains two menisci: medial and lateral. The menisci are pieces of cartilage that sit between the femur and tibia and provide shock absorption, stability and increases joint depth. The medial meniscus is c-shaped and is more stable due to its attachment to the medial collateral ligament. The medial meniscus is more prone to injury due to a higher incidence of medial knee injuries while the lateral meniscus is o-shaped and less prone to injury.

Blood Supply
The outer 1/3 of the meniscus is called the red zone due to its rich blood supply. If an injury occurs in this area it has the potential to heal on its own or it can be repaired with surgery via sutures. The inner 2/3 is called the white zone because it lacks blood supply. Tears in this zone must be surgically removed because the meniscus is unable to heal itself without nutrients and blood supply.

external image Meniscal%20tear.jpg

Biomechanics
The closed pack position of the knee is full extension. The loose pack position is 30 degrees of knee flexion. The capsular pattern of restriction is greater loss of flexion over extension.

Arthrokinematics
  • During flexion (open chain) the concave surface of the tibia rolls and glides posteriorly on the convex femoral condyles.
  • During extension (open chain) the concave surface of the tibia rolls and glides anteriorly on the convex femoral condlyes.

Mechanism of Injury
1. Compression
  • Overweight and obese individuals are often more susceptible to this
2. Deterioration
  • Often occurs in older individuals
3. Rotation
  • Often the knee is somewhat flexed and then rotated. An example of this would be when cutting during sports

Types of Tears
Tears are named for the shape and location of the tear:
1. Longitudinal (can progress into a bucket handle)
2. Bucket Handle
3. Radial (can progress into a parrot beak)
4. Parrot beak
5. Horizontal (can progress into a flap)
6. Flap
7. Mixed/complex
A sport related meniscal tear can often times occur with other injuries to the knee such as an ACL or MCL tear.

Netter_Meniscus.png
Meniscal Repair
Repairs of meniscus injuries are very effective for patients between the ages of 20-50 years old. Tears can be referred to as red-red, red-white, or white-white; with the name indicating which vascular zone the tear extends through. Surgical repair of the meniscus is indicated if the patient is active and younger than 60 years old and if the tear is of the red-red or red-white type. If the tear is in the white-white region, if the patient is over 60, sedentary, or if the tear is due to chronic degeneration then the tear is treated with a partial resection.

Signs/Symptoms
Common signs and symptoms of meniscal tear include: pop or tearing sensation, pain (increases with weight bearing activities), stiffness, swelling, weakness/ "giving out" of the knee, and decreased range of motion. If a piece of the mensicus breaks loose after the tear, an individual may experience locking/catching of the knee. Often times, athletes will still play on their injury and then the symptoms will increase in intensity in the days following.

Practical Presentation
Along with the above symptoms, certain special tests will also be positive for a patient with a meniscal injury. Special tests are positive if pain, clicking, or catching is present and include:
  • Tenderness and pain upon palpation along the joint line.
  • McMurray's test
  • Apley's compression and distraction test. Distraction will cause a relief in symptoms in the presence of meniscal injury. If this portion of the test is positive, it may indicate a ligamentous tear.
  • Ege's test and Thessaly's test

EGE'S TEST


THESSALY'S TEST

meniscus_normal.jpg meniscus_torn.jpg

Treatment

Duration
According to the protocol by Lowe, rehabilitation for meniscal injury can extend up to 36 weeks. However, the Palomar protocol listed return to sport with no restrictions can occur as early as 6 months. In the article by Shiraev et al., it states that a patient will be seen for 2x/week for 8 weeks. The Lowe protocol states that this goal will be met between weeks 4-12. The duration will then be decreased to once a week throughout the duration of treatment to progress towards more functional activities such as running, squatting and sport specific activities as the protocol allows. A running program is typically not initiated until at least month 3.

Conservative Treatment
For tears located in the red zone of the meniscus, conservative treatment may be used. This includes RICE, NSAIDS, possible weight-bearing precautions, strengthening, stretching, and modality usage. There is little research regarding specific protocol regimes for conservative treatment.

Post-Surgical Rehab Protocol


http://www.drwaltlowe.com/attachments/wysiwyg/File/MeniscusRepairProtocol.pdf

Exercises and Modalities

Week 1-2
Exercises
  • quad set
  • straight leg raise (SLR) in four planes
  • short arc quad (SAQ)
  • seated marching
  • heel slides
  • ankle pumps
  • gastroc/soleus stretch
  • hamstring/ITB stretch
  • Low Load Long Duration (LLLD) to facilitate extension
Modalities
  • E-stim
  • Biofeedback
  • Cryotherapy
Goals of Phase
  • Control pain, inflammation, and effusion
  • Adequate quad/VMO contraction
  • Independent in HEP

Week 2-4
Exercises
  • continue stretching and LLLD
  • multi-angle isometrics (0-60 degrees)
  • knee Extension ROM
  • heel/toe raises
  • leg press
  • wall squats
  • weight shifting
  • bicycle
  • continue modalities as needed
Goals of Phase
  • ROM 0 - 120 degrees
  • control pain, inflammation, and effusion
  • partial weight bearing (PWB) to full weight bearing (FWB) with good quad control

Week 4-12
Exercises
  • continue stretches and LLLD extension exercise
  • continue bicycle or elliptical
  • mini squat
  • hamstring curl
  • lateral/forward step/step down
  • lunges
  • balance training
    • single leg balance with plyotoss
    • sports cord agility work
    • wobble board
    • 1/2 foam roller work
  • continue modalities as needed
Goals of Phase
  • ROM 0 - 135 degrees
  • increase lower extremity strength and endurance
  • improve proprioception, balance, and coordination
  • readiness for sport specific activity

Week 12-36
Exercises
  • continue stretches and LLLD
  • running program
    • water walking
    • swimming (kicking)
    • backward run
  • cutting program
    • lateral shuffle
    • carioca, figure 8's
  • functional training
    • light plyometric program
    • sport specific drills
  • continue modalities as needed
Goals of Phase
  • enhance neuromuscular control
  • progress skill training
  • sport specific activity - unrestricted activity
  • achieve maximal strength and endurance
(Note: For more detail, please reference the protocol by Dr. Lowe)

Palomar Protocol
http://www.palomarortho.com/protocols/meniscusrepair.pdf

Adjunct Therapy

Chiropractic: The article by Polkinghorn is a case study examining a 54 year old woman who presented with a meniscal tear. According Polkinghorn, chiropractic can be used as a successful conservative treatment for meniscal injury via mechanical force to the knee. A chiropractic specific tool was used to make adjustments to the knee. This treatment along with homeopathic therapy resulted in complete resolution of the patient's functional limitations. The patient had full return to function with no symptoms associated.

Another chiropractic article by Jorosz and Ames is a case report examining a 60-year-old woman who presented to a chiropractic clinic with a meniscal tear. The chiropractor used a conservative form of treatment for the patient, which included therapeutic ultrasound, RICE, soft tissue massage and mechanically assisted adjustment techniques to the knee. The patient also underwent an athletic taping and strength program to facilitate strengthening of the vastus lateralis obliquus. After treatment, the patient was able to perform most activities without symptoms and also demonstrated large decreases of pain in self reported scales.

A case study by Jun Xu M.D. and Hong Su C.M.D. explain how acupunture can be used as an alternative treatment for meniscus injuries. These treatments are based on traditional Chinese medicine techniques. Multiple sites can be used depending on the condition of the injury. Different sites are used for acute versus chronic stages which are classified as either Wind hot or Wind cold. A case study of a 45 year old male had 2-3 treatments before all swelling had subsided and pain gradually decreased over the course of 6 sessions.

Neuromuscular electrical stimulation (NMES) can be used as an adjunct treatment for a meniscal tear to help re-educate the quadriceps. NMES can help to educate the muscle in what the "normal" pattern / action of the muscle is. It can also be used for edema reduction, contracture management, and muscle strengthening. The use of NMES is indicated after surgery or injury that causes muscular weakness or poor activation patterns. It helps to increase sensory input to the muscle and re-establish control. The goal is to elicit mid-tetany. Recommended settings are: pulse duration 300-600 microseconds, pulse rate 35-45 pulse per seconds, ramp time 2-3 seconds, and on/off ratio 1:1 – 1:5. Treatment time usually lasts around 15-20 minutes and can be repeated several times a day. (Vanhoose)

Surgical Outcomes
In the article by Noyes et al they discussed the importance of preserving the meniscus after injury in order for optimal joint function and patient outcomes. The authors discussed how menisectomy can often lead to more joint deterioration. The menisectomy option is often used when the tears are large and extend into the avascular regions. This article found that there has been a good success rate with suturing longitudinal tears that are large and extend partially into the white zone of the meniscus. These types of tears are referred to as “red-white” tears and are repairable due to part of the tear receiving blood supply. The authors further go one to discuss the use of joint line tenderness, positive McMurray’s test, and MRI imaging for diagnosing meniscus injuries.

This article also discusses the use of possible strategies to enhance the healing of the avascular portions of the meniscus. The possible techniques discussed include cell based therapy where articular chondrocytes are implanted into the meniscus and platelet rich plasma therapies which contain growth factors and may stimulate cell proliferation. This article states that further studies need to be conducted to prove the efficacy of these techniques.

The clinical outcomes for 198 patients undergoing meniscal repair of tears that extended into the middle third region were analyzed 2 years post repair by Noyes et al. The authors found that 20% of patients required re-operative repairs; the incidence of re-operative repair was dependant upon the initial type of tear. Tears that were longitudinal had the highest incidence rate, with radial, horizontal, and flap all following respectively in re-operative rates. Thus, indicating that the type of tear and reapir will influence the overall patient outcomes. Overall the study found that preservation of the meniscus is highly important for maintaining knee function, especially in the young and/or active patient populations. (Noyes et al.)

References
Chris, Gabriel. “Functional Testing and Return to Sport.” OrthoCarolina Sports Performance. Web 16 Apr. 2012 http://www.hickoryortho.com/uploads/file/Functional%20Testing%20and%20Return%20to%20Sport%20-%20Chris%20Gabriel.pdf.

Denney, Linda. (2012, February 28). The Knee [powerpoint]. Musculoskeletal III. Kansas City, KS.


Dutton, M. (2008). Orthopaedic: examination, evaluation and intervention 2nd edition. United States of America: McGraw-Hill Companies Inc.
Jarosz, Brett S., and Rick A. Ames. "Chiropractic Management of a Medial Meniscus Tear in a Patient with Tibiofemoral Degeneration: A Case Report." Journal of Chiropractic Medicine 9.4 (2010): 200-08. PubMed. Web. 16 Apr. 2012. <http:www.ncbi.nlm.nih.gov/pmc/articles/PMC3206581/>.

"Meniscal Tears - OrthoInfo - AAOS." American Academy of Orthopedic Surgeons. AAOS, Feb. 2009. Web. 16 Apr. 2012. <http://orthoinfo.aaos.org/topic.cfm?topic=a00358>.

Noyes, Frank R., and Sue D. Barber-Westin. "Management of Meniscus Tears That Extend into the Avascular Region." Clinics in Sports Medicine 31.1 (2012): 65-90. Print.

O'Meara, Patrick. "Patrick O'Meara Orthopaedic Surgeon Escondido San Diego."Palomar Orthopaedic Specialists. Palomar Othopaedic Specialists. Web. 16 Apr. 2012. <http://www.palomarortho.com/orthopedic-doctors/meniscus-repair.htm>.

Polkinghron BS. "Conservative Treatment of Torn Medial Meniscus via Mechanical Force, Manually Assisted Short Lever Chiropractic Adjusting Procedures." Journal of Manipulative and Physiological Therapeutics 17.7 (1994): 474-84. PubMed. Web. 16 Apr. 2012. <http://www.ncbi.nlm.nih.gov/pubmed/7989881>.

Sharma, Neena. (2011, February 14). The Knee Joint [powerpoint]. Musculoskeletal I. Kansas City, KS.

Shiraev, Tim, Suzanne E. Anderson, and Nigel Hope. "The Royal Australian College of General Practitioners." RACGP. Australian Family Physician, Apr. 2012. Web. 16 Apr. 2012. <http://www.racgp.org.au/afp/201204/46219>.

Utech, Nora. (2011, February 14). Meniscal Injury [powerpoint]. Musculoskeletal I. Kansas City, KS.

Vanhoose, Lisa. (2011, February 2). Neuromuscular Electrical Stimulation [powerpoint]. Interventions II. Kansas City, KS.

Vorvick, Linda J., Benjamin Ma, and David Zieve. "Meniscus Tears: MedlinePlus Medical Encyclopedia." U.S National Library of Medicine. U.S. National Library of Medicine, 12 Mar. 2012. Web. 16 Apr. 2012. http://www.nlm.nih.gov/medlineplus/ency/article/001071.htm.

Xu, Jun, and Hong Su. "29. Acupuncture and Knee Pain and Meniscus Tear." 29. Acupuncture and Knee Pain and Meniscus Tear. Web. 16 Apr. 2012. <http://www.drxuacupuncture.com/?p=1490>.