Medial Collateral Ligament Tear
Medial Collateral Ligament Tear
Claudia Dal Molin
Delmas J. Bolin
Basics
-
Superficial component is primary restraint to valgus stress.
-
Deep portion has tight connection to medial meniscus.
-
Medial collateral ligament (MCL) connects with the posteriomedial corner structures and is a secondary stabilizer in resisting external rotation and anterior-posterior translation of the knee.
Description
-
Tension injury to the MCL occurs most commonly with a valgus stress (ie, a blow to the lateral knee).
-
Grade of injury classified by symptoms and physical exam by degree of joint opening with applied valgus stress at 0° and 30° of knee flexion:
-
Grade I: minimal fiber tearing, localized tenderness, no instability (0–5 mm of laxity)
-
Grade II: greater degree of ligamentous tearing, slight-to-moderate abnormal motion (6–10 mm of laxity)
-
Grade III: complete tear, demonstrable instability (>10 mm of laxity)
-
Epidemiology
Incidence
MCL is most frequently injured ligament of the knee (1).
General Prevention
Prophylactic knee bracing is controversial; most studies demonstrate bracing protects MCL and increases force required to produce failure. Some studies suggest athletes perceive decreased performance while using brace (1,2).
Commonly Associated Conditions
-
Medial meniscus tear, commonly in the posterior horn
-
Anterior cruciate ligament (ACL) tear
-
Posterior oblique ligament injury; anteromedial rotatory instability
-
Dislocation of the knee (rare)
Diagnosis
History
-
In contact/collision sports, an acute blow to the lateral aspect of the knee when the foot is planted results in a valgus stress:
-
The medial joint line is under tension and can open, producing “buckling” and an injury to the MCL (closed-chain injury).
-
-
The injury may be seen in soccer players who are struck on the instep while passing the ball (open-chain injury).
-
Skiers can injure MCL by noncontact valgus external rotation injury.
-
Overuse injuries to the MCL have been reported in breaststroke swimmers.
-
History of a “pop” should suggest associated meniscus or ACL injury.
Physical Exam
-
Observe for antalgic gait; inquire about a sense of the knee being “loose.”
-
Inspect the knee for ecchymosis, swelling, effusion, and presence of deformity. Presence suggests greater extent of injury. In pediatric patients, ecchymosis and swelling necessitate evaluation for physeal injury.
-
Palpate for localized tenderness over medial joint line and course of MCL, including adductor tubercle and proximal medial tibia.
-
Assess range of motion for deficit at full extension (MCL) or flexion (MCL and joint effusion).
-
Perform valgus stress at full extension and 30° of knee flexion. Valgus laxity at 30° alone indicates an isolated MCL injury. Laxity at both 0° and 30° indicates injury to the MCL and posterior oblique ligament, knee capsule, and/or anterior cruciate ligaments. Always compare the exam to the unaffected knee.
-
Degree of injury (as opposed to grade) assessed by findings: 1st degree, pain but no laxity; 2nd degree, pain and laxity but firm endpoint present on valgus stress test at 30°; 3rd degree, no end point is present on valgus stress test at 30°.
-
Determine the amount of joint line opening. If >10 mm, coexisting intra-articular pathology (torn ACL or meniscus) will be present 80% of the time.
-
Posterior oblique ligament injury can lead to anteromedial rotatory instability and posterior horn medial meniscus tears. Anterior drawer testing with the foot in external rotation can assess anteromedial translation, but may be difficult to perform in acute injury.
-
Lachman's exam to evaluate a concomitant ACL tear; McMurray's exam to evaluate the menisci for injury
-
Assess neurovascular status of the extremity; popliteal nerve and artery injuries associated with instability can be limb-threatening and should not be missed.
Diagnostic Tests & Interpretation
Imaging
-
Standard radiographic knee series (45-degree flexion weight-bearing, lateral, and sunrise views) usually normal, but used to identify avulsions or osteochondral fragments
-
Stress radiographs are useful in adolescents to exclude Salter-Harris (physeal) injuries; used when tenderness presents completely around physis.
-
Calcification of the MCL (Pellegrini-Stieda lesion) is seen in chronic MCL injury (3).
-
T2 MRI is gold standard and demonstrates acute intrasubstance edema and fiber discontinuity with acute MCL tears, and identifies associated bone contusions (45% of MCL injuries) and associated injuries, including ACL and meniscal tears (1).
Differential Diagnosis
-
Medial meniscus tear
-
Medial knee contusion
-
Patellar instability, subluxation, or dislocation
-
Fracture of the distal femoral physis
Treatment
-
Grade I injuries:
-
Ice applied 20 min every 3–4 hr; avoid lateral knee, as more vigorous icing has led to cryoinjury of common peroneal nerve
-
Weight-bearing as tolerated, with or without assistive device, when able to walk without limp
-
Active range of motion (ROM) exercises and achievement of full ROM as soon as tolerated
-
Strengthening exercises (open- and closed-chain) as tolerated
-
Progression towards agility, proprioceptive, and sport-related drills as tolerated
-
In both grade I and II MCL injuries, PRICE (protection, rest, ice, compression, elevation) and NSAIDs are first-line treatments.
-
-
Grade II injuries:
-
Weight-bearing as tolerated with long-leg brace. Brace may be locked in extension for 1–2 wks, depending on comfort level and degree of valgus opening. Discontinuation of brace is dependent on pain, anatomic alignment, and degree of laxity present.
-
Active ROM exercises are started immediately.
-
Quadriceps strengthening and electrical stimulation, as well as straight leg raises, are started immediately. Stationary cycling and resistive exercises are initiated as tolerated.
-
Proprioception and agility drills can begin once full ROM and functional strength are achieved.
-
-
Grade III injuries:
-
Long-leg brace is worn and locked in extension for 3–6 wks, depending on anatomic alignment. Non-weight-bearing is recommended in patients with more severe valgus alignment for no more than 3 wks.
-
For patients with normal alignment, immediate ROM out of the brace 2–3 times/day is performed. For patients who are “knock-kneed,” ROM out of the brace begins at 3 wks. The brace should remain locked in extension for 6 wks.
-
Weight-bearing is determined by the degree of laxity. Progressive weight-bearing begins after the determined non-weight-bearing period as tolerated.
-
Strengthening of quadriceps is done with quad sets, straight leg raise, and electrical stimulation. Closed-chain exercises are initiated, depending on the patient's weight-bearing status.
-
Proprioception, agility drills, bracing, and return to sport are the same as in grade II injuries. Isolated grade III injuries with tolerable symptoms can be rehabilitated similarly.
-
There is no difference in outcome for immobilization, early mobilization, and surgery, although patients treated with early rehabilitation were able to return to sport faster and were slightly more unstable at follow-up.
-
-
Combined MCL/ACL injuries:
-
Early referral to orthopedics, especially if rotatory instability is suspected
-
MRI is helpful to delineate pathology.
-
Surgical approach remains controversial. Initial rehab mirrors that of grade III MCL injuries for the 1st 6 wks. ACL reconstruction is performed after 6 wks and when full ROM has been achieved. If excessive valgus laxity is present, combined ACL-MCL reconstruction may be recommended. ACL reconstruction alone: Weight-bearing as tolerated with long-leg brace locked in extension for 10–14 days. ROM exercises are permitted, and strengthening exercises are initiated. ACL-MCL reconstruction: Non-weight-bearing for 6 wks with brace locked in extension for 3 wks. Brace is unlocked at 3 wks, and ROM exercises are initiated as tolerated. Partial weight-bearing is initiated at the end of wk 6 and progressed to full by wk 10. Functional brace is used and strengthening exercises begun after wk 10, and proprioception is permitted once full weight-bearing is achieved. Return to sports is the same as in grade II injuries.
-
Aggressive rehabilitation is undertaken to restore knee motion and get through the inflammatory phase of the injury. Then the ACL is usually reconstructed and the MCL is permitted to scar down on its own. This approach has minimized postoperative arthrofibrosis.
-
Rehabilitation protocols after surgery are similar to ACL protocols. If there is significant rotational instability, repair of the MCL is often performed as well.
-
P.377
Medication
Short-term use of NSAIDs is helpful in decreasing pain and swelling. The authors use piroxicam 20 mg daily for 2–3 wks because of its collagen-synthesis stimulation as well as NSAID properties (4).
Ongoing Care
-
Grade I injuries:
-
Bracing is preferable for contact-related sports; football lineman at the college and occasionally at the high school levels will wear prophylactic MCL braces (1,5)
-
Return to sport is acceptable when level of strength, agility, and proprioception is equivalent (usually 90% of) to the uninvolved extremity.
-
Grade I injuries may be able to return to play in as little as 10 days to 2 wks.
-
-
Grade II injuries:
-
Return to play based on functional ability similar to that of grade I injuries; a hinged or custom MCL brace may be used for comfort and confidence of the athlete.
-
Grade II usually return to play in 21–28 days.
-
-
Grade III: Conservative management:
-
May require more than 28 days to return to full function. Consider surgical consultation for those athletes who fail conservative management or who develop pain with chronic instability.
-
Follow-Up Recommendations
-
Referral is suggested when there is suspicion of ACL or meniscal injury.
-
Some clinicians have suggested arthroscopy for all complete MCL injuries with more than 6 mm of joint opening.
Complications
The Pellegrini-Stieda lesion can be seen on radiographs; represents calcification of the previously injured MCL.
References
1. Miyamoto RG, Bosco JA, Sherman OH. Treatment of medial collateral ligament injuries. J Am Acad Orthop Surg. 2009;17:152–161.
2. Chen L, Kim PD, Ahmad CS, et al. Medial collateral ligament injuries of the knee: current treatment concepts. Curr Rev Musculoskelet Med. 2008;1:108–113.
3. Reider B. Medial collateral ligament injuries in athletes. Sports Med. 1996;21:147–156.
4. Hanson CA, Weinhold PS, Afshari HM, et al. The effect of analgesic agents on the healing rat medial collateral ligament. Am J Sports Med. 2005;33:674–679.
5. Albright JP, Powell JW, Smith W, et al. Medial collateral ligament knee sprains in college football. Effectiveness of preventive braces. Am J Sports Med. 1994;22:12–18.
Additional Reading
Azar FM. Evaluation and treatment of chronic medial collateral ligament injuries of the knee. Sports Med Arthrosc. 2006;14:84–90.
Ballmer PM, Jakob RP. The non operative treatment of isolated complete tears of the medial collateral ligament of the knee. A prospective study. Arch Orthop Trauma Surg. 1988;107:273–276.
Edson CJ. Conservative and postoperative rehabilitation of isolated and combined injuries of the medial collateral ligament. Sports Med Arthrosc. 2006;14:105–110.
Schweitzer ME, Tran D, Deely DM, et al. Medial collateral ligament injuries: evaluation of multiple signs, prevalence and location of associated bone bruises, and assessment with MR imaging. Radiology. 1995;194:825–829.
Codes
ICD9
844.1 Sprain, medial collateral, knee
Clinical Pearls
-
How long until I can return to play? For most sports, athletes with grade I injuries return in an average of 10 days. Those with grade II sprains return in 2–3 wks. Those with grade III sprains return in 3–6 wks. Soccer players may require several more weeks because the use of the instep to kick and pass the ball exerts a valgus force that subjects the injured MCL to recurrent stress. Operative treatment of combined injuries can require 6–12 mos of rehabilitation prior to full return.
-
Bracing is recommended for all grades of MCL injury. Grade III injuries may require up to a full year of bracing, depending on residual laxity.
-
A 10-yr follow-up on isolated MCL injuries suggests that most patients have excellent function and no major radiographic evidence of arthritis.
-
After rehabilitation, most patients note only minor symptoms; 10-yr studies show most perform well with only minor decreases in physical ability.