Treatment & Rehabilitation of Grade II Medial Collateral Ligament (MCL) Injury

Introduction
The superficial medial collateral ligament (MCL), and other medial knee stabilisers (most notably the deep medial collateral ligament and the posterior oblique ligament) are the most commonly injured ligamentous structures of the knee (Grood, et al., 1981; Hughston, 1981; Phisitkul, et al., 2006; van der Esch, et al., 2006).
The majority of MCL tears are isolated and predominantly occur in young people participating in sports activities. Typically, the mechanism of injury involves valgus knee loading, external rotation or a combined force vector- particularly prevalent in sports such as football and skiing which involve these type of forces and repetitive knee flexion (Peterson, et al., 2000).

In the United States, occurence of these types of injuries to the knee has been reported to be 0.24 per 1000 during any given 12 month cycle and to be twice as high in males – 0.36 compared with 0.18 in females (Daniel, et al., 2003). In actual fact, the incidence of these types of injury is probably much higher than reported as many minor MCL injuries are never even assessed or treated by medical personnel.
In terms of treatment, the approach to medial knee injuries has changed dramatically over recent years. As the understanding of the anatomy, biomechanics, and causes of medial knee injuries has evolved, as has the treatment. Whilst in the 1970’s and 1980’s surgical treatment for MCL injuries was common place, today most MCL injuries are treated conservatively with early rehabilitation (Phisitkul, et al., 2006). In general, all isolated Grade I and II tears and even the majority of Grade III tears can be treated non-operatively with a supervised, functional, rehabilitation program. Excellent results can be expected with return to full pre-injury activity level being the norm (Bradley, et al., 2006).
This paper will research and interpret some of the relevant literature that is available to us, with the aim of developing and implementing a functional rehabilitation plan (in keeping with the principles of soft tissue healing) that is suitable for the treatment of a Grade II MCL injury of a 33-year-old, male, semi-professional footballer (the patient).
General Knee Anatomy
The knee joint, is the largest and most complex synovial joint of the human body (Bradley, et al., 2006).
Figure 1: Anterior view of the patellofemoral joint. Hawkins (2009)
The patella, patella ligament and femur combine to form the patellofemoral joint (Saladin, 2001). The patella itself is a triangular-shaped sesamoid bone that is attached to the quadriceps tendon. This tendon inserts into the trochlear groove on the femur and primarily acts to increase the ‘mechanical advantage’ of the quadriceps muscle group (Hamill & Knutzen, 1995).
The lateral and posterior aspects of the knee joint are encapsulated by a joint capsule whilst the anterior section of the knee is protected by the patella ligament (and its retinacula). The quadriceps and the hamstrings are the prime movers of the knee joint – knee ‘extensors’ and ‘flexors’ respectively.
The quadricep group of muscles are located on the anterior part of the thigh and comprise of the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. They converge on the patella tendon, travel over the patella and insert onto the tibial tuberosity. In addition to knee extension, the quadriceps group of muscles (in combination with the iliopsoas) are also responsible for flexion of the hip (Saladin, 2001). The hamstring muscles are found on the posterior section of the thigh and comprise of the biceps femoris, semimembranosus, and semitendinosus. They are responsible for the flexion of the knee joint and (together with the gluteus maximus) the extension of the hip joint (Saladin, 2001).
The main stabilisers of the knee are the quadriceps tendon (to front of the thigh) and the semimembranosus tendon (at the back of the thigh) (Saladin, 2001). The medial and lateral collateral ligaments are primarily responsible for preventing the knee from rotating during extension (Saladin, 2001). The anterior cruciate ligament and the posterior cruciate ligament stop anterior and posterior translation of the tibia relative to the femur (Saladin, 2001).
Specific Medial Collateral Ligament Anatomy
Medial knee stability is provided, for the most part, by its ‘medial static’ and its ‘dynamic’ stabilisers. The medial static stabilisers, which work as an integrated unit, are the superficial MCL, the posterior oblique ligament and the middle third of the deep MCL. The dynamic stabilisers are the per anserinus tendons – most notably the semimembranosus tendon (Peterson & Renstrom, 2001).
The superficial MCL is, on average, 11cm long and 0.5cm wide. It originates from the medial femoral condyle (anterior to the tubercle) and travels, distally, to insert 5-7cm below the joint line on the anteromedial tibia (just below the insertion of pes anserinus tendons). The anterior fibres of the superficial MCL tense during knee flexion whilst its posterior fibres slacken. The superficial MCL is tight during external rotation of the knee (Peterson & Renstrom, 2001).
The middle third of the deep MCL is a short structure – about 2-3cm long – and is attached to the meniscus underlying the MCL. This part of the ligament is relatively ‘slack’ to facilitate knee motion whilst short enough to hold the meniscus firmly in position. In terms of injury, the deep MCL can be ruptured both proximally and distally to the meniscal attachment (regardless of the location of the tear of the superficial MCL). The posterior oblique ligament is a thick capsular ligament originating just behind the superficial MCL (at the condyle just below the joint line). The posterior oblique ligament becomes ‘slack’ during knee flexion (Peterson & Renstrom, 2001).
Biomechanics
Biomechanical studies show that the MCL’s main function is to resist valgus (outward side motion of the leg) and external rotation forces of the tibia in relation to the femur .
The superficial MCL has been found to be responsible for 57% of medial stability at 5? of knee flexion and up to 78% at 30? knee flexion. The deep MCL accounted for 8% at 5? and 4% at 30? whilst the posterior oblique accounted for 18% and 4% respectively.
Mechanism of Injury
The player reported to the clinic approximately 24 hours after the injury occurred. The player was able to weight bear. When asked how the injury occurred the player stated that he was running at pace to ‘close down an opposing player’ and then described performing a ‘change of direction’ or ‘cutting’ manoeuvre. He stated that as he planted and pushed off his right leg, he experienced a sudden excruciating localised pain and an immediate lack of stability in his right knee. This caused him to collapse.
As stated, the primary mechanism of injury to the MCL is most commonly a valgus stress (Fetto, et al., 1978). However, due to the position of the knee and the force vectors involved, a combined flexion/valgus/external rotation injury is usually the end result (Hayes, et al., 2000). The vast majority of MCL injuries are from a lateral force to the distal femur with the foot being fixed to the ground, although non-contact valgus external rotation injuries are common – the latter being particularly prevalent in sports such as football and skiing (Perryman, et al., 2002; Pressman, et al., 2003).
Because of the complexities of knee injuries, it is important to perform a complete knee examination in order to rule out other potential problems such as fractures, cruciate ligament tears, menisci ruptures or chondral cartilage damage (Bradley, et al., 2006).
Physical Examination/Clinical Assessment
The best time for examination of the knee is immediately after the injury before muscle spasm occurs (Phisitkul, et al., 2006). Unfortunately, as in this case, that is not always feasible. However, a 24 hour period of rest and immobilisation (which the patient undertook) is usually sufficient for muscle spasm to subside and relaxation to occur (Hughston, et al., 1976). This allows an effective examination and assessment of the injury.
The injury was examined and assessed through a combination of subjective and objective approaches.
Important initial information obtained through speaking with the patient and preliminary observations included the location of pain, the ability to ambulate after the injury, time and onset of swelling, the presence of deformity, and the immediate site of tenderness (Indelicato & Linton, 2003).
The location of oedema and tenderness can accurately identify the injury site of the superficial collateral ligaments in 64% and 76% of cases respectively (Hughston, et al., 1976). The exact location of injuries of the deep MCL and the posterior oblique ligament are more difficult to palpate because of their deep-seated position, but pain and tenderness in this area can at least indicate the presence of injury to these posteromedial structures (Sims & Jacobsen, 2004)
On asking the patient to indicate the most painful spot, he pointed to the medial aspect of the right knee joint. The area indicated by the patient suggested injury to the MCL. Contralateral comparison of the knees was carried out in order to identify areas of oedema and/or deformity. Significant swelling and slight discolouration was observed on the medial aspect of the right knee joint. Upon palpation of both knee joints, a noticeable heat differential was felt in the affected area.
While keeping the patient relaxed, a valgus stress test (MCL test) was performed with the knee in 30? of flexion (figure 1), and compared to the contralateral knee as a control. The examination was then repeated with the knee in 0? of flexion to recruit the function of remaining posteromedial structures (figure 2). The valgus stress test proved positive in contralateral comparison in 30? of flexion and negative in 0? of flexion. The absence of laxity in the second test reduced suspicions of any associated injuries to the secondary restraints such as the cruciate ligaments and the posterior capsule.
In addition, a number of other tests were carried out to assess whether any injuries, commonly associated with MCL injuries, were prevalent (bone bruises, ACL tears, lateral collateral ligament tears, medial meniscus tears, lateral meniscus tears, and posterior collateral ligament tears). Anteromedial rotatory instability (often present when there is evidence of anterior subluxation of the medial tibial plateau during a valgus stress test with the knee in 30? of flexion) was assessd by performing the anterior drawer test (figure 3) whilst holding the tibia in external rotation. This proved negative and therefore ruled out the possibility of a posterolateral knee injury rather than a medial knee injury. Lachman’s test (figure 4) and the Pivot shift test (figure 5) were also performed to negate the existence of any ACL rupture whilst Murray’s test (figure 6) was carried out to assess the integrity of the Meniscus cartilage. All these tests also proved negative.
The results of the assessment supported the initial belief that the patient was suffering a superficial MCL injury with the posterior oblique ligament still intact and no associated damage to either the cruciate ligaments or meniscus cartilage of the knee.
Radiograph
In accordance with the Ottawa knee rules (Stiell, et al., 1997) it was decided that radiographs were not required for this injury. More recent work has shown the Ottawa knee rules to be very successful in reducing unnecessary radiography, whilst ensuring a high level of recognition fractures (Bachman, 2003). The Ottawa knee rules state that a radiograph is required only in patients who have an acute knee injury with one or more of the following:
Age 55 years or older
Tenderness at head of fibula
Isolated tenderness of patella
Inability to flex to 90°
Inability to bear weight both immediately and in the emergency department
Classification of Injury
In 1976 (revised in 1994) Hughston standardised MCL injury classification into two related systems – the severity system (Grade I, II & III) and the laxity system (grade 1+, 2+ & 3+).
Under this combined classification system, Grade I involves a few damaged fibres resulting in localised tenderness but no instability or laxity. A Grade II injury involves a disruption to substantially more fibres, with more generalised tenderness but still no instability (although it is not uncommon for a degree of laxity with the knee in 30? flexion). A Grade III injury is a complete tear of the ligament with resultant instability and laxity. Grade III injuries are then sub-classified according to the extent of laxity (determined by the amount of absolute joint separation from valgus stress with the knee in 30? of flexion). Grade 1+, 2+, and 3+ laxities indicate 3-5 mm, 6-10 mm, and more than 10 mm of absolute medial separation respectively.
Fetto and Marshall (1978) defined Grade I injuries as those without valgus laxity in both 0? and 30? of flexion, Grade II injuries as those with valgus laxity in 30? of flexion but stable in 0? of flexion, and Grade III as those with valgus laxity in both 0? and 30? of flexion.
The injury was subsequently classified as an isolated Grade II MCL injury in accordance with Hughston (1976 & 1994) and Fetto & Marshall (1976).
Using a full return to sport as an indicator of a successful end point, Ellsasser et al (1974) treated 74 professional football players with incomplete tears of the MCL using a functional rehabilitation program. In this study, a success rate of 98% was found compared with a 74% success rate for a separate group treated surgically. In the non-operative group, return to play occurred between 3 and 8 weeks.
Return to play was even quicker in a study by Derscheid and Garrick (1981). They treated football players with Grade I and Grade II injuries with a specific rehabilitation programme. Players with Grade I MCL injuries returned to full play in an average of 10.6 days, whereas those with Grade II MCL injuries returned in an average of just 19.5 days, with neither group showing a propensity for injury reoccurrence.
Based on this research, a consensus on the time it would take for the patient to return to full sporting activeity would be 3-8 weeks.
Treatment and Rehabilitation Objectives
An appropriate treatment and rehabilitation plan is required to restore normal function to the knee joint and the surrounding soft tissues with a view to enabling the patient to return to his sport as early and effectively as possible – with no residual symptoms and a minimal risk of injury reoccurrence
All soft tissue injuries, regardless of their nature and severity, undergo the same three stages of healing – the inflammatory phase, proliferation phase and the remodelling phase. The time required to complete each healing stage is dependent up on the nature and severity of the injury. However, of note, numerous investigations comparing surgical and non-surgical treatment have reported no advantages of surgical intervention over non-surgical intervention (Quarles & Hosey, 2004; Phisitkul et al., 2006).
The following treatment and rehabilitation plan was designed and implemented to address the needs of the patient.
Inflammatory Phase (up to 72 hours post injury)
The inflammatory phase is characterised by heat, redness, swelling and pain – generally leading to a loss of movement and function. The goals of treatment at this stage were:
Protect injury
Control oedema
Prevent associated muscle atrophy
Regain range of motion
Increase weight bearing capacity
Maintain general fitness/strength
P.R.I.C.E (Protection, Rest, Ice, Compression and Elevation)
The P.R.I.C.E. regimen is employed following injury with a view to controlling the haemorrhage, decreasing inflammation, reducing tissue metabolism and minimising secondary hypoxic injury, cell debris and oedema. Research has suggested that the sooner after injury that cold therapy (cryotherapy) is started, then the more beneficial the reduction in metabolism will be (Knight et al., 2000). Elevation has been shown to have a significant effect on reducing effusion (O’Donohue, 1976).
The patient reported that he had already applied ice intermittently during the 24 hour period between injury occurrence and assessment – approximated to have fulfilled 4 x 20 minute applications of crushed ice at 2 hourly intervals with the knee in an elevated position in line with commonly agreed protocol. He also reprted that he had kept the injured limb elevated for sustained periods.
Measurement
On inspection the right knee was swollen over the lateral aspect with a small amount of visible bruising. At this time the patient was asked to indicate his level of pain using a visual analogue scale (VAS). Measurement of the girth of the knee was also taken using a tape measure whilst active flexion and was also assessed using a goniometer. These measurements would be continually reassessed throughout the rehabilitation process in order to assess progress and outcomes.
Continued active flexion was also encouraged at this time. Simple ‘knee bend and straighten’ exercises, with the patient lying in a supine position on an exercise mat – the movement repeated 10-20 times, 3 times a day, with a view to increasing active range of movement (figure 1) . The patient was also instructed in different exercises to maintain cardiovascular fitness and upper body conditioning.
The patient also received a massage to the upper and lower leg (particularly the quadriceps group of muscles) in an elevated position using effleurage techniques to aid removal of waste products via the lymphatic system – reflexive muscular inhibition of the quadriceps has been thought to be the result of the pain associated with MCL injury (Dixit, et al., 2007). The knee was then strapped.

Strapping
The knee was strapped to assist healing and reduce the risk of aggravating the injury. The knee was strapped in a position of 30? flexion with the lower leg partially rotated inwards (figure 1). A combination of ‘lower leg and thigh anchors’, ‘medial cross’ and ‘medial straight line’ taping techniques, using zinc oxide tape and elastic adhesive dressing, were employed to provide suitable support for the patient and reduce and valgus stress (figure 2).
Experience has shown that this type of strapping is preferable to the use of a knee braces in Grade II MCL injuries as the strapping can be re-applied whenever required with the correct level of compression and support required. There is some concern that functional braces may expose athletes to additional risk by imparting a false sense of confidence. It is reported that lower extremity muscle strengthening, flexibility improvements, and technique refinement are more important than functional bracing in treating ligamentous knee injuries (Christenson, 2010).
The patient was advised to continue elevating the limb, as much as possible, for the following 24 to 48 hours.
Anti-inflammatory medication
Non-steroidal anti-inflammatory medication (ibuprofen) was prescribed to the patient, via NHS Direct, two hours after injury.
Whilst some studies have shown no early adverse affect of nonsteroidal anti-inflammatory drugs on the strength of healing torn MCL’s (Moorman, et al., 1999), it remains controversial as to whether inhibiting the inflammatory response is uniformly advantageous. Pain and disability following injury are in part due to the inflammatory response and, whist it is suggested that decreasing the inflammation decreases the symptoms (therefore allowing earlier rehabilitation) (Weiler, 1992), it is also important to consider that inflammatory cells are responsible for clearing away cell debris and necrotic fibres – and without this phagocytic function regeneration may not be able to begin (Reynolds et al., 1995, Almekinders et al., 1986, Jones 1999).
As the patient reported that the pain had subsided over the last 24 hours (measured using a visual analogue scale), he was advised to continue taking the non-steroidal anti-inflammatory medication only when necessary.
Proliferation Phase (3-21 days post injury)
The proliferation stage involves the repair and regeneration of the injured tissue (development of new blood vessels, fibrous tissue formation, re-epithelialisation and wound contraction) and begins approximately 72 hours after injury. The goals of this rehabilitation phase included:
? Decrease effusion
? Decrease pain
? Restore full range of motion
? Enhance joint strength
? Introduce proprioceptive exercise
?Achieve full pain free weight bearing statu
Maintain general fitness and strength levels
It has been stated that ligaments heal with a stronger and more organised collagen fibril architecture when early mobilisation and exercise is employed during the healing process (Osborne and Rizzo, 2003). Therefore, in addition to continuing the treatments introduced during the inflammatory phase (ice, intermittent compression, and massage), manual joint mobilisation techniques were also employed at this stage. Comprehensive zinc oxide and elastic adhesive strapping, removed and re-applied by the patient whenever necessary (particularly during active flexion exercises), was also continued. Pain scale assessment, ankle girth measurement and goniometer measurements were continually monitored throughout the proliferation phase.
As stated, n the proliferation phase, the goals are to continue re-establishing full range of motion, increase muscular strength/power/endurance, and adding in functional activities. Exercises include isotonic exercises to isolate and strengthen particular muscle groups, such as in the hip and thigh regions (knee extension, leg press, hamstring curls and hip exercises). In order to re-establish the dynamic stability of the knee joint, it is crucial to strengthen the hip and calf musculature, with an emphasis on progressive Closed Kinetic Chain exercises (such as wall squats, step-ups, lateral lunges and stair climbing) that foster proprioception (Wilk et al., 1996).
Range of Movement (RoM)
Range of movement exercises were significantly progressed from the inflammatory phase. Active and passive movements continued with the addition of manual mobilisation techniques for the knee joint. The following advanced knee stretches were utilised with a view to restoring movement to the joint and improve flexibility of muscles crossing the knee. The patient was advised to carry out each separate muscle group stretch 3 times daily (provided they do not cause or increase pain).
i. Quadriceps Stretch
Treatment couch was used for balance. Heel taken towards your bottom, keeping knees together and back straight until patient felt a stretch in the front of their thigh (figure 1). Held for 15 seconds and repeated 4 times at a mild to moderate stretch (pain free).
ii. Hamstring Stretch
Patient’s foot was placed on chair. With knee and back straight, patient leant forward at hips until he felt a stretch in the back of his thigh/knee (figure 2). Held for 15 seconds and repeated 4 times at a mild to moderate stretch (pain-free).
iii. Calf Stretch
With patient’s hands placed against the wall, his leg was stretched behind him as demonstrated in figure 3. Keeping his heel down, knee straight and feet pointing forwards, the patient gently lunged forwards until he felt a stretch in the back of his calf/knee. Held for 15 seconds and repeated 4 times at a mild to moderate stretch (pain-free).
iv. ITB Stretch
Patient’s leg was placed behind his other leg and taken as far away from him as was comfortably possible. Patient then pushed his hips to the side of his leg until he felt a stretch in the outer thigh/hip (figure 4). Back was kept straight throughout. Held for 15 seconds and repeated 4 times at a mild to moderate stretch (pain-free).
v. Adductor Stretch
Standing tall, and with back straight, pateint’s feet were placed approximately twice shoulder width apart. Patient then gently lunged to one side, keeping his other knee straight, until he felt a stretch in the groin of his straight leg (figure 5). Held for 15 seconds and repeated 4 times at a mild to moderate stretch (pain-free).
Increased range of motion was also enhanced by using a stationary bicycle (Wilk et al., 1996).