Knee collateral ligament injuries

Diagnosis is made on clinical history and examination. If there is no history of injury other structures should be considered as the more likely cause of symptoms.

On observation there may be heat, swelling and deformity with pain at end range of flexion and extension. In severe injuries testing ligamentous integrity may have to be delayed until the subacute phase when swelling and bleeding are under control. Both lateral and medial ligament are under tension when a lateral rotation strain is placed on the knee but varus and valgus tests in extension or inner range will help differentiate. Palpation of the suspected ligament structure may be painful.

Posterolateral Corner (PLC)

Posterolateral Complex is defined as the fibular collateral ligament, popliteofibular ligament and popliteus tendon and are the most important structures for posterolateral knee stability. Injuries to the posterolateral complex are potentially disabling. Specialist referral is necessary for appropriate assessment and management and to ensure optimal functional outcomes for people.

Because these injuries are relatively rare and complex (usually combined with ACL/PCL tears), and the interpretation of diagnostic tests for these injuries difficult, people with these injuries should be referred for specialist assessment.

Anterior Cruciate Ligament Injuries

Patient reported symptoms: immediate pain and tense swelling following trauma (usually after non-contact situation e.g. landing from jump, pivoting or decelerating suddenly), often accompanied by an audible pop, crack or feeling of something going out/popping back. Subsequent instability and locking is common (Brukner et al., 2007).

Clinical signs: a tense effusion, restricted range of movement, widespread tenderness on palpation, laxity on testing the affected cruciate ligament and or collaterals, and a positive McMurrays test (Brukner et al., 2007).

Posterior Cruciate Ligament injuries

Acute presentation: effusion, stiffness, mild to moderate pain in the posterior aspect of knee, pain with deep knee flexion, such as squatting /kneeling

Chronic presentation: vague anterior knee pain, difficulty up/down stairs, pain with sprinting or deceleration.

May present with tibial external rotation, genu recurvatum, may have flexed knee gait to avoid terminal extension with lack of end range flexion due to premature posterior tibial displacement. Posterior Drawer Test most sensitive (90%) and specific (99%) for PCL injuries (Cho et al., 2001) and is graded 0 I II III based on amount of posterior translation at medial joint line. Other diagnostic tests include Posterior Sag Test, Quadriceps Active Test, and the Whipple test.  Classification based on posterior subluxation of tibia relative to femoral condyles (with knee in 90° of flexion).

• Grade I (partial)
  • 1-5 mm posterior tibial translation
  • tibia remains anterior to the femoral condyles
• Grade II (complete isolated)
  • 6-10 mm posterior tibial translation
  • complete injury in which the anterior tibia is flush with the femoral condyles
• Grade III (combined PCL and capsuloligamentous)
  • >10 mm posterior tibial translation
  • tibia is posterior to the femoral condyles and often indicates an associated ACL and/or PLC injury

Knee collateral ligament injuries (Day et al 2009)

For example:

• Abduction (valgus) stress testing (medial) (Video Link)
  
  Patient positioned in long sitting. Clinician on side to be tested with one hand supporting thigh and taking weight of upper leg. The other hand is grasping the medial aspect of the calf or ankle. Distraction force applied to the medial aspect of the knee joint. Test in 0° extension and 20-30° flexion. Positive test at 20°; mild injury - pain over medial joint line with no laxity, moderate injury - pain over medial joint line and some laxity, rupture – pain and gross instability, visual gapping of medial joint line. The knee should be stable at 0° therefore any instability would be positive test.
• Adduction (varus) testing (lateral) (Video Link)
  
  The patient is positioned in long sitting with hip abducted. The clinician supports medial and underside of thigh above the medial joint line. The other hand grasps the outer surface of the calf towards the ankle. A distraction force is applied to the lateral aspect of the knee. Positive test at 20°; mild injury - pain over lateral joint line with no laxity, moderate injury - pain over lateral joint line and some laxity, rupture - pain and gross instability, visual gapping of lateral joint line. The knee should be stable at 0° therefore any instability would be positive test.

Posterolateral Corner (PLC)

For example:

• Dial Test
  Increased external rotation of the tibia, and increased lateral opening on varus stress should alert the clinician to the involvement of the posterolateral complex.
• Special clinical tests for this area include the external rotation recurvatum test, posterolateral drawer testing, adduction stress test and the reversed pivot shift test. These tests have been well described, but are complex and difficult to perform and interpret. They are best performed by experienced practitioners.

Anterior Cruciate Ligament Injuries (Day et al, 2009)

For example:

• Anterior drawer (Video Link)
  
  The patient is positioned in long sitting with hip flexed to approximately 40°, knee flexed to approximately 90°, foot resting on plinth and ankle in corresponding PF. Clinician identifies knee joint line and grasps the superior aspect of the tibia. Keeping thumbs on the joint line either side of the patella tendon, the clinician pulls the tibia forward. Positive test a soft end feel or excessive anterior translation compared to other side.
• Lachmanns (Video Link)
  
  The patient is positioned in long sitting with knee in 15° of flexion and foot resting on plinth. Clinician stands on side of patient (clinically knee flexion is often maintained by resting patients knee over clinicians knee). One hand is used to stabilise the femur while the other hand grasps the calf, below the knee joint line. Must ensure that hamstrings and quadriceps are relaxed to ensure no false positives. Clinician initiates a clean forward ‘jerk’ motion of the hand on the calf to quickly draw the tibia forwards. Positive result a soft end feel or excessive translation compared to other side.
• Pivot shift (Video Link)
  
  The patient is positioned in long sitting or supine. Hip in 50-70° flexion, knee in 45° flexion. Clinician supports the limb. Clinician applies pressure to outer surface of the leg, just below the joint line onto the head of fibula. The other hand stabilises the foot while a valgus force is produced by applying an inward pressure through the upper hand. Simultaneously, a medial rotation forces is applied to the lower leg as the clinician slowly extends the knee. Positive result is an obvious ‘slip’, ‘jerk’ or ‘clunk’ at around 10-20° of flexion.

Posterior Cruciate Ligament injuries (Day et al, 2009)

• Posterior drawer (Video Link - one handed and Video Link - two handed)
  
  The patient is positioned in long sitting, hip 40-50° flexion, knee 90° flexion and foot resting flat on the plinth. Clinician stabilises the tibia with one hand while applying an anterior posterior glide to tibia just below the joint line. Positive result increased glide of tibia posteriorly compared to other knee.
• Posterior sag
  The patient is positioned in long sitting with hip 40-50° flexion, knee 90° of flexion and foot resting flat on the plinth. Clinician ensures that quadriceps and hamstrings are relaxed. Observe knee from lateral position to check for step or sag at the joint line. Positive test visible posterior sag of the tibia on the femur.
• Quadriceps Active Test
  The patient is positioned in supine with hip in 45°flexion and knee 90° flexion. Look at the tibia to “sag” compared to the femur. The clinician sits on the affected limb to stabilise. Ask the patient to actively contract their quadriceps. A positive test occurs if the patient’s tibia shifts forward.

• ALL INJURIES FOLLOW EARLY CARE PLAN
• PEACE and LOVE
• Rehab as per guidelines
• Non-surgical:
  • Simple ligament injury 6-8 week rehab
  • Complex injury - 6 months rehab

Patient centred care

Treatment should take into account individual patient needs, preferences, expectations and functional status.  Clinical reasoning should inform treatment based on subjective and objective findings. Good communication between therapist and patient is essential if a successful outcome is to be achieved.  Treatment options should be clearly explained so that patients can make informed decisions with regard to their care and management.

Evidence based strategies

Knee Collateral Ligament

The medial collateral ligament is the most frequently injured ligament of the knee (Miyamoto et al., 2009).  Collateral ligament injuries are usually traumatic involving a varus or valgus strain on a fixed foot.  Depending on position of the knee during trauma concomitant damage may occur to the menisci or cruciate ligaments.

If the lateral collateral ligament is injured other structures may be implicated e.g. cruciate, popliteal nerve and injuries to the posterolateral corner of the knee are serious. Vascular compromise and altered sensory or motor function require urgent surgical intervention and therefore immediate referral.

Conservative treatment has been shown to be effective at ten year follow up (Lunberg & Messner, 1996). Research suggests that injuries of the medial collateral ligament up to Grade III magnitude usually heal spontaneously and that surgical repair followed by immobilisation of an isolated MCL tear does not enhance the healing process (Woo et al., 2000. However care must be taken to exclude the presence of concomitant injuries that may require surgical intervention and influence outcome.

Generally the literature pertaining to management of collateral ligament injuries is dated. Conservative treatment follows the basic principles common to all soft tissue injuries such as PEACE and LOVE, avoiding harm, pharmacological management and active rehabilitation. Despite the widespread use of exercise interventions in the rehabilitation of this group of patients, there is insufficient evidence to establish the effectiveness of any one type of intervention (Thompson et al., 2002).

The New Zealand Guidelines Group proposes the following diagnostic criteria and makes the following recommendations for the medial collateral ligament:

Criteria

• Grade I (0-5mm of medial opening and minimal ligament disruption)
• Grade II (5-10mm of medial opening and moderate ligament disruption)
• Grade III (>10mm of medial opening and severe ligament disruption and no endpoint)

Grade I and II injuries are best managed with early functional rehabilitation without the need for bracing. Return to sport can be expected in 6-8 weeks (Derscheid & Garrick, 1981; O’Connor, 1979; Bergfield, 1979; Cox, 1979; Holden et al., 1983).  Management of Grade III is similar but bracing is recommended for the first 4-6 weeks until the knee is stable (Expert opinion).

Anterior Cruciate

The anterior cruciate ligament (ACL) is the primary stabilising structure within the knee, limiting anterior translation of tibia on the femur as well as tibial internal rotation. Injuries are more common in high demand sports and usually follow non- contact trauma such as landing incorrectly from a jump, pivoting or decelerating suddenly, but can occur after direct contact or collision. Often more than one structure is involved with damage to the menisci and articular cartilage reported on MRI imaging. Subsequent instability and locking is common and reconstructive surgery followed by lengthy rehabilitation is often required to stabilise the joint. Although there is general consensus that post-operative rehabilitation is essential, the components of programmes vary.

There is on-going debate within the literature on whether ACL tears can be successfully managed with a conservative approach using neuromuscular rehabilitation or whether surgical management is best (Meuffels, et al., 2009; Delincé & Ghafil, 2012).

Early weight bearing & motion

• Statistically significant difference in anterior knee pain (decreased in the early motion/weight bearing group)
• No deleterious effects of early weight bearing on stability or function (Wright et al., 2008a)

Open Kinetic Chain v Closed Kinetic Chain

• Moderate evidence of no significant difference in pain, function and knee laxity (Lobb et al., 2012)
• Limited evidence of significant differences: CKC exercises presented with better pain, laxity, subjective outcomes and return to sport at 1 year (Trees et al., 2005; Anderson et al., 2009)
• Significant increase in quads strength with OKC exercises added into a CKC programme at 6 weeks (Wright et al., 2008b)
• Increased rate of return to play in the combined OKC(at 6 weeks)/CKC group at 31 months (Risberg et al., 2004; Wright et al., 2008b)
• OKC exercises should be introduced slowly
  • Not before 8 weeks secondary to an increased risk of laxity (in hamstring grafts)
  • Should be between 90° and 40° initially
  • Increase range by 10° per week thereafter (Renstrom et al., 2008)

Home based v clinic based

• Moderate evidence of no significant difference in strength, function, range of movement and knee laxity (Lobb et al., 2012)
• Minimally supervised programmes (0-6 physiotherapy sessions alongside home exercise programme) can result in successful ACL rehab (Wright et al., 2008a)

Accelerated (19/52) v non-accelerated (32/52) rehab

• Limited evidence of no significant difference in function and knee laxity at 2 years (Lobb et al., 2012)
• No deleterious effects from a 19 week programme compared to a thirty two week programme or any statistical differences for any parameters between groups at any point (Wright et al., 2008b)

Water based v land based exercise

• Limited evidence of no significant difference in strength two months (Lobb et al., 2012)
• Equally effective in restoring quads strength but land based exercises produces greater hamstring strength (Risberg et al., 2004)
• Water based exercises more effective in decreasing effusion (Risberg et a.l., 2004)

Neuromuscular training

• Perturbation training results in a higher rate of return to sport without giving way (Risberg et al., 2004)
• 73.4% decrease in risk of non-contact ACL injuries (43.8% decrease in overall injury risk) when neuromuscular training included in prophylactic exercise programmes (Sugimoto et al., 2012)

Neuromuscular Electrical Stimulation (NMES)

• Can improve quads strength but studies dated (Wright et al., 2008b)

Posterior cruciate

Non-operative

• Often recommended when PCL is injured in isolation. Grade I, II and III tears (as described above) can be managed without surgical intervention (Harner & Roher, 1998; Matava, Ellis & Gruber., 2009)

Surgical management

• Recommended in acute injuries with severe posterior tibial subluxation and instability with greater than 10mm of posterior translation or multiple injuries, i.e. to the ACL or posterolateral corner (Iwamoto et al., 2004; Margheritini et al., 2002).

Conservative management

• Grade I to II lesions
  • Return to sport 2-4 weeks (Pepe & Horner, 2001)
  • Focus of rehab is working on lower extremity kinematics rather than a specific group in isolation.
  • Eccentric training for Quads and Hams
  • Closed chain work
  • Once strength, endurance and neuromuscular control have been achieved the patient can return to an agility based programme (Rosenthal et al., 2012)
• Grade III lesions
  • Can be immobilised 2-4 weeks in full extension
  • Basic SLR and Quads setting 2-4 weeks
  • Active – assisted motion begins and WB as tolerated (Flexion past 70° and isolated hamstrings are avoided)
  • Closed chain ex’s & eccentric open chain
  • Quads Functional Ex’s – biking, leg press, elliptical & stair climbing
  • Return to sport 3 months (depending on sport) (Harne & Roher, 1998; Wind et al., 2004)

Post-operative

• Consult local guidelines where available

Non evidence based strategies

Knee Collateral Ligament

Exercise

• Few studies looking at this on own, mainly in conjunction with ice and show benefit in short term only.
• Insufficient evidence to establish the effectiveness of any one type of exercise intervention (Thompson et al., 2002).

Ice

• Insufficient evidence to suggest cryotherapy improves the overall clinical outcome of soft tissue injuries. Studies have shown a reduction in tissue temperature, blood flow, pain and metabolism but nowhere shows if this improves overall treatment outcome.
• Ice most beneficial (mainly looking at pain relief) in short term, when used days 1-3, for 10-20 minutes, 2-4 times each day. However, a lack of evidence based guidelines for appropriate use of ice
• Ice best used in conjunction with exercise (Bleakely et al., 2004; McAuley, 2001; Collins, 2008; Hubbard et al., 2004)

Ultrasound

• Little evidence that therapeutic ultrasound is more effective than placebo ultrasound for treatment of soft tissue injuries (Baker et al., 2001; Ter Haar, 1999)
• Low intensity, pulsed ultrasound applied to the knee MCL in rats showed some mechanical advantage in ligament days 2-12, but no advantage by day 21 (Karnes & Burton, 2002)

Pulsed short wave diathermy

• No long term benefit in treatment of soft tissue injuries with PSWD (Shields et al., 2001)

Soft tissue massage/mobilisation/frictions

• Insufficient evidence to support use in this condition. No evidence that frictions promote repair of sprained ligaments (Walker, 1984)

Acupuncture

• Insufficient evidence to show that acupuncture for acute knee soft tissue injuries improves long term outcome

Strapping/taping

• Little evidence to show any long term benefit.
• In acute injuries, adhesive tape can prevent extremes of physiological range which can enable the part to be used more normally (McLean, 1986)
• Kinesio-taping – further studies needed to quantify effects of taping on pain levels and changes in motor activity. Further research required to determine how and why this tape works (Morris et al., 2013).

Anterior cruciate

Bracing

• Strong evidence of no significant difference to range of movement, strength, laxity, pain, function from bracing as an adjunct to standard treatment (Lobb et al., 2012)
• No increase in post op injuries, pain, range of movement deficits or laxity found in non-braced groups therefore bracing not necessary (Wright et al., 2008a)

Continuous Passive Movement

• Moderate evidence of no significant difference with the use of CPM alongside standard treatment in range of movement and knee laxity (Lobb et al., 2012)
• No statistically significant differences between groups, CPM in first 30 days is similar to early active motion (Wright et al., 2008a)

Progressing as expected (up to 3 Rxs) before discharge or onward referral.

Refer to ortho, GP, other.

Escalation

Criteria to refer on:

Collateral ligament

• Orthopaedic review is recommended for suspected injuries to the posterolateral corner (see below), or where there is indication of meniscal or cruciate ligament involvement.
• Immediate referral is recommended for those with posterolateral corner injury where concurrent injury of the Common Peroneal nerve is not uncommon.

Anterior cruciate

• Young and active individuals with persisting instability and locking predisposing to further internal damage and early degenerative change, or where there is the likelihood of concomitant meniscal damage, or failure to progress with conservative treatment.
• Conservative management should be tried for at least 6 to 8 weeks without improvement before escalation is considered.

Posterior cruciate

• When the non-operative other ligamentous structures are involved increasing the rotational instability of the knee or when non-operative management has failed or knee begins to show increased OA changes.
• Immediate referral for orthopaedic opinion if suspected posterolateral corner injury in addition to PCL as there is a suggested window of less than three weeks to achieve adequate repair. Surgery within 2 weeks allows for best anatomical repair and least capsular scarring (Wind et al., 2004)
• Ongoing pain and / or instability following 3 months of conservative rehabilitation.

Brukner P, Khan K. Clinical sports medicine. 3rd ed. ed. Australia: McGraw-Hill; 2007

ACL Guidelines

BERGFELD, J., 1979. Symposium: functional rehabilitation of isolated medial collateral ligament sprains. First-, second-, and third-degree sprains. The American Journal of Sports Medicine, 7(3), pp. 207-209.

COX, J.S., 1979. Symposium: functional rehabilitation of isolated medial collateral ligament sprains. Injury nomenclature. The American Journal of Sports Medicine, 7(3), pp. 211-213.

DERSCHEID, G.L. and GARRICK, J.G., 1981. Medial collateral ligament injuries in football. Nonoperative management of grade I and grade II sprains. The American Journal of Sports Medicine, 9(6), pp. 365-368.

HARNER, C.D. and HOHER, J., 1998. Evaluation and treatment of posterior cruciate ligament injuries. The American Journal of Sports Medicine, 26(3), pp. 471-482.

HOLDEN, D.L., EGGERT, A.W. and BUTLER, J.E., 1983. The nonoperative treatment of grade I and II medial collateral ligament injuries to the knee. The American Journal of Sports Medicine, 11(5), pp. 340-344.

MACAULEY, D.C., 2001. Ice therapy: how good is the evidence? International Journal of Sports Medicine, 22(5), pp. 379-384.

MARGHERITINI, F., RIHN, J., MUSAHL, V., MARIANI, P.P. and HARNER, C., 2002. Posterior cruciate ligament injuries in the athlete: an anatomical, biomechanical and clinical review. Sports medicine (Auckland, N.Z.), 32(6), pp. 393-408.

O'CONNOR, G.A., 1979. Symposium: functional rehabilitation of isolated medial collateral ligament sprains. Collateral ligament injuries of the joint. The American Journal of Sports Medicine, 7(3), pp. 209-210.

PEPE, M.D.; HARNER, C.D., 2001. Assessment and surgical decision making for PCL injuries in athletes. Athletic Therapy Today,6,pp. 9-15.

SHIELDS, N. 2001. Short-wave diathermy: a review of existing clinical trials. Physical Therapy Reviews, 6(2), pp. 101-108.

WALKER, J.M., 1984. Deep transverse frictions in ligament healing*. The Journal of orthopaedic and sports physical therapy, 6(2), pp. 89-94.

ANDERSSON, D., SAMUELSSON, K. and KARLSSON, J., 2009. Treatment of anterior cruciate ligament injuries with special reference to surgical technique and rehabilitation: an assessment of randomized controlled trials. Arthroscopy : The Journal of Arthroscopic & Related Surgery : Official Publication of the Arthroscopy Association of North America and the International Arthroscopy Association, 25(6), pp. 653-685. Link here (link correct as at 25/8/15)

BAKER, K.G., ROBERTSON, V.J. and DUCK, F.A., 2001. A review of therapeutic ultrasound: biophysical effects. Physical Therapy, 81(7), pp. 1351-1358. Link here (link correct as at 21/8/15)

BLEAKLEY, C., MCDONOUGH, S. and MACAULEY, D., 2004. The use of ice in the treatment of acute soft-tissue injury: a systematic review of randomized controlled trials. The American Journal of Sports Medicine, 32(1), pp. 251-261. Link here (link correct as at 21/8/15)

COLLINS, N.C., 2008. Is ice right? Does cryotherapy improve outcome for acute soft tissue injury? Emergency medicine journal : EMJ, 25(2), pp. 65-68. Link here (link correct as at 21/8/15)

DELINCE, P. and GHAFIL, D., 2012. Anterior cruciate ligament tears: conservative or surgical treatment? A critical review of the literature. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 20(1), pp. 48-61. Link here (link correct as at 25/8/15)

HUBBARD, T.J., ARONSON, S.L. and DENEGAR, C.R., 2004. Does Cryotherapy Hasten Return to Participation? A Systematic Review. Journal of athletic training, 39(1), pp. 88-94. Link here (link correct as at 21/8/15)

KARNES, J.L. and BURTON, H.W., 2002. Continuous therapeutic ultrasound accelerates repair of contraction-induced skeletal muscle damage in rats. Archives of Physical Medicine and Rehabilitation, 83(1), pp. 1-4. Link here (link correct as at 21/8/15)

LOBB, R., TUMILTY, S. and CLAYDON, L.S., 2012. A review of systematic reviews on anterior cruciate ligament reconstruction rehabilitation. Physical therapy in sport : official journal of the Association of Chartered Physiotherapists in Sports Medicine, 13(4), pp. 270-278. Link here (link correct as at 25/8/15)

MCLEAN, D.A., 1989. Use of adhesive strapping in sport. British journal of sports medicine, 23(3), pp. 147-149. Link here (link correct as of 25/8/15)

MEUFFELS, D.E., FAVEJEE, M.M., VISSERS, M.M., HEIJBOER, M.P., REIJMAN, M. and VERHAAR, J.A., 2009. Ten year follow-up study comparing conservative versus operative treatment of anterior cruciate ligament ruptures. A matched-pair analysis of high level athletes. British journal of sports medicine, 43(5), pp. 347-351. Link here (link correct as at 25/8/15)

MORRIS, D., JONES, D., RYAN, H. and RYAN, C.G., 2013. The clinical effects of Kinesio(R) Tex taping: A systematic review. Physiotherapy theory and practice, 29(4), pp. 259-270. Link here (link correct as at 21/8/15)

RENSTROM, P., LJUNGQVIST, A., ARENDT, E., BEYNNON, B., FUKUBAYASHI, T., GARRETT, W., GEORGOULIS, T., HEWETT, T.E., JOHNSON, R., KROSSHAUG, T., MANDELBAUM, B., MICHELI, L., MYKLEBUST, G., ROOS, E., ROOS, H., SCHAMASCH, P., SHULTZ, S., WERNER, S., WOJTYS, E. and ENGEBRETSEN, L., 2008. Non-contact ACL injuries in female athletes: an International Olympic Committee current concepts statement. British journal of sports medicine, 42(6), pp. 394-412. Link here (link correct as at 25/8/15)

ARNA RISBERG, M., LEWEK, M. and SNYDER-MACKLER, L., A systematic review of evidence for anterior cruciate ligament rehabilitation: how much and what type? Physical Therapy in Sport, 5(3), pp. 125-145. Link here (link correct as at 25/8/15)

ROSENTHAL, M.D., RAINEY, C.E., TOGNONI, A. and WORMS, R., 2012. Evaluation and management of posterior cruciate ligament injuries. Physical therapy in sport : official journal of the Association of Chartered Physiotherapists in Sports Medicine, 13(4), pp. 196-208. Link here (link correct as at 25/8/15)

SUGIMOTO, D., MYER, G.D., MCKEON, J.M. and HEWETT, T.E., 2012. Evaluation of the effectiveness of neuromuscular training to reduce anterior cruciate ligament injury in female athletes: a critical review of relative risk reduction and numbers-needed-to-treat analyses. British journal of sports medicine, 46(14), pp. 979-988. Link here (link correct as at 25/8/15)

TER HAAR, G., 1999. Therapeutic ultrasound. European journal of ultrasound : official journal of the European Federation of Societies for Ultrasound in Medicine and Biology, 9(1), pp. 3-9. Link here (link correct as at 21/8/15)

THOMSON, L.C., HANDOLL, H.H., CUNNINGHAM, A. and SHAW, P.C., 2002. Physiotherapist-led programmes and interventions for rehabilitation of anterior cruciate ligament, medial collateral ligament and meniscal injuries of the knee in adults. The Cochrane database of systematic reviews, (2)(2), pp. CD001354. Link here (link correct as at 21/8/15)

TREES, A.H., HOWE, T.E., DIXON, J. and WHITE, L., 2005. Exercise for treating isolated anterior cruciate ligament injuries in adults. The Cochrane database of systematic reviews, (4)(4), pp. CD005316. Link here (link correct as at 25/8/15)

WIND, W.M.,JR, BERGFELD, J.A. and PARKER, R.D., 2004. Evaluation and treatment of posterior cruciate ligament injuries: revisited. The American Journal of Sports Medicine, 32(7), pp. 1765-1775. Link here (link correct as at 25/8/15)

WRIGHT, R.W., PRESTON, E., FLEMING, B.C., AMENDOLA, A., ANDRISH, J.T., BERGFELD, J.A., DUNN, W.R., KAEDING, C., KUHN, J.E., MARX, R.G., MCCARTY, E.C., PARKER, R.C., SPINDLER, K.P., WOLCOTT, M., WOLF, B.R. and WILLIAMS, G.N., 2008. A systematic review of anterior cruciate ligament reconstruction rehabilitation: part II: open versus closed kinetic chain exercises, neuromuscular electrical stimulation, accelerated rehabilitation, and miscellaneous topics. The journal of knee surgery, 21(3), pp. 225-234. Link here (link correct as at 25/8/15)

WRIGHT, R.W., PRESTON, E., FLEMING, B.C., AMENDOLA, A., ANDRISH, J.T., BERGFELD, J.A., DUNN, W.R., KAEDING, C., KUHN, J.E., MARX, R.G., MCCARTY, E.C., PARKER, R.C., SPINDLER, K.P., WOLCOTT, M., WOLF, B.R. and WILLIAMS, G.N., 2008. A systematic review of anterior cruciate ligament reconstruction rehabilitation: part I: continuous passive motion, early weight bearing, postoperative bracing, and home-based rehabilitation. The journal of knee surgery, 21(3), pp. 217-224. Link here (link correct as at 25/8/15)