History

Fact Explanation
Popping sound at time of injury Commonly heard in non contact injury, often occurs while changing direction or landing from a jump (hyper-extension or pivot combination).[1],[2]
Pain When hemarthrosis is present, the increased intra-articular volume produces considerable pain on movement [1],[2]
Swelling Due to hemarthrosis of the knee, usually within 6 hours of injury [3]
Feeling of instability or giving way when walking The primary function of the ACL is to prevent anterior translation of the tibia on the femur. Those who have only a mild injury may notice that the feels unstable when bearing weight. [1],[2]
Difficulty in ascending stairs Ascending stairs requires stability of the ACL. [4]
History of sudden deceleration or cutting, pivoting or sidestepping maneuvers. Common mechanism of injury. Women are at higher risk of non-contact injury of the ACL [1],[2]
Contact injury Occurs due to hyperextension or forced inward movement of the knee. [1],[2]
References
  1. CIMINO F, Volk BS., et al. Anterior cruciate ligament injury: diagnosis, management, and prevention. American Family Physician. October 2010, vol.82(8). 917-922 [viewed 5 March 2014]. Available from: http://www.aafp.org/afp/2010/1015/p917.html
  2. SPINDLER KP, Wright RW. Clinical practice. Anterior cruciate ligament tear. New England Journal of Medicine. April 2008, vol.359(20). 2135–2142 [viewed 5 March 2014]. Available from: http://www.nejm.org/doi/full/10.1056/NEJMc082471#t=article DOI: 10.1056/NEJMc082471
  3. MICHAEL T, Ballas., et al. Commonly Missed Orthopedic Problems. American Family Physician. January 1998, vol.15;57(2). 267-274 [viewed 5 March 2014]. Available from: http://www.aafp.org/afp/1998/0115/p267.html
  4. COLBY S, Francisco A., et al. Electromyographic and Kinematic Analysis of Cutting Maneuvers: Implications for Anterior Cruciate Ligament Injury. American Journal of Sports Medicine. 2000, vol.28(2). 234-240 [viewed 5 March 2014].

Examination

Fact Explanation
Positive Lachman test The most accurate test for detecting anterior cruciate ligament injury. Asymmetry in side to side laxity or a soft end point is indicative of ACL tear. [1],[2],[3]
Positive Anterior Drawer test Anterior excrusion of the tibia in relation to the femur is compared to the unaffected knee. [1],[2]
Positive Pivot Shift test When extending an ACL deficient knee, a small amount of translation (anterior) of the tibia results in relation to the femur. During flexion, translation reduces resulting in the pivoting of tibia into its proper femoral alignment. Note; these tests difficult to perform in the acute phase because of pain. [1],[2],[3]
Joint asymmetry and loss of the peripatellar groove Indicates an effusion, hemarthrosis or both [3]
Reduced range of movements of the knee joint - loss of hyperextension Lack of hyperextension favors ACL tear (the torn ACL stump compressed between the tibia and femur, as well as the joint effusion, prevents full extension). Associated hemarthrosis, guarding and musle spasm resulted due to pain also limit the range of movements. [3]
Increased anterior knee translation when measured using arthrometer Intact or partial ACL tears have less than 3mm of increased anterior translation on the arthrometer(KT-1000 test), while all patients with an ACL tear had 3mm or more if increased translation, compared to the normal contralateral knee. [3]
References
  1. CIMINO F, Volk BS., et al. Anterior cruciate ligament injury: diagnosis, management, and prevention. American Family Physician. October 2010, vol.82(8). 917-922 [viewed 5 March 2014]. Available from: http://www.aafp.org/afp/2010/1015/p917.html
  2. SPINDLER KP, Wright RW. Clinical practice. Anterior cruciate ligament tear. New England Journal of Medicine. April 2008, vol.359(20). 2135–2142 [viewed 5 March 2014]. Available from: http://www.nejm.org/doi/full/10.1056/NEJMc082471#t=article DOI: 10.1056/NEJMc082471
  3. ROBERT F LaPrade. KT-1000 testing clinical exam. The Steadman Clinic. [viewed 5 March 2014]. Available from: drrobertlaprademd.com/kt-1000-testing-for-acl-tear

Differential Diagnoses

Fact Explanation
Medial collateral ligament injury Important to exclude as it is the most commonly injured ligament in the knee joint and several ligament injuries may occur simultaneously. Consider this diagnosis if there is point tenderness at the medial joint line, localized soft tissue swelling at the medial aspect of the knee, reproducible pain with valgus stress. [1],[2]
Posterior cruciate ligament injury Less common than ACL injuries and often unrecognized.Patient presents with difficulty in descending stairs. Positive Posterior drawer test and posterior tibial sag can be demonstrated. False positive Lachman test also can be demonstrated. [1],[3]
References
  1. CIMINO F, Volk BS., et al. Anterior cruciate ligament injury: diagnosis, management, and prevention. American Family Physician. October 2010, vol.82(8). 917-922 [viewed 5 March 2014]. Available from: http://www.aafp.org/afp/2010/1015/p917.html
  2. SPINDLER KP, Wright RW. Clinical practice. Anterior cruciate ligament tear. New England Journal of Medicine. April 2008, vol.359(20). 2135–2142 [viewed 5 March 2014]. Available from: http://www.nejm.org/doi/full/10.1056/NEJMc082471#t=article DOI: 10.1056/NEJMc082471
  3. MICHAEL T, Ballas., et al. Commonly Missed Orthopedic Problems. American Family Physician. January 1998, vol.15;57(2). 267-274 [viewed 5 March 2014]. Available from: http://www.aafp.org/afp/1998/0115/p267.html

Investigations - for Diagnosis

Fact Explanation
Magnetic Resonance Imaging (MRI) MRI is the primary investigation used to diagnose anterior cruciate ligament injury and also can identify other concomitant injuries such as meniscal tear, collateral ligament injuries.[1],[2]
Knee joint x-rays (radio-graphic knee series) including anterior-posterior, lateral, tunnel and sunrise views. Initial assessment for fractures. Evaluates knee alignment, determine skeletal maturity and identify degenerative changes in middle aged patients.[1],[2]
Arthrometer testing This test (arthrometer KT-1000) is performed to provide an objective assessment of increased anterior knee translation between 20 and 30 degrees of knee flexion. It provides objective assessment of both the diagnosis of an ACL tear and the healing of an ACL reconstruction graft. [3]
References
  1. CIMINO F, Volk BS., et al. Anterior cruciate ligament injury: diagnosis, management, and prevention. American Family Physician. October 2010, vol.82(8). 917-922 [viewed 5 March 2014]. Available from: http://www.aafp.org/afp/2010/1015/p917.html
  2. SPINDLER KP, Wright RW. Clinical practice. Anterior cruciate ligament tear. New England Journal of Medicine. April 2008, vol.359(20). 2135–2142 [viewed 5 March 2014]. Available from: http://www.nejm.org/doi/full/10.1056/NEJMc082471#t=article DOI: 10.1056/NEJMc082471
  3. ROBERT F.LaPrade. KT-1000 testing clinical exam. The Steadman Clinic. [viewed 5 March 2014]. Available from: drrobertlaprademd.com/kt-1000-testing-for-acl-tear

Investigations - Fitness for Management

Fact Explanation
Serum Creatinine, Serum electrolytes To assess the renal function prior to anesthesia.[1]
Full Blood Count To assess the hemoglobin level, platelet count since it is an anesthetic requirement. [1]
Prothrombin time and INR To assess the bleeding tendency prior to anesthesia. [1]
AST and ALT enzyme levels To assess the liver functions prior to anesthesia.[1]
Chest X-ray As an anesthetic requirement. [1]
Electrocardiogram ( ECG ) As an anesthetic requirement. [1]
References
  1. American society of anesthesiologists. Standards and Practice Parameters. Basic Standards For Pre-anesthesia Care. October 2010.

Management - General Measures

Fact Explanation
First line therapy - Rest the knee, apply ice , apply compression bandage, elevate above level of the heart. To reduce hemarthrosis (This process helps decrease the swelling and reduce the pain). [1]
Mobility aids - crutches Used if the patient has considerable discomfort on ambulation. [1],[2]
Opioid analgesics Opioid medications mimic the actions of endorphins by interacting with several opioid receptors in the body. Mainly indicated to relieve severe pain and for the post operative pain relief. Can administer orally, intramuscularly, intravenously, or by intraarticular infusion. Eg: Morphin, Bupivacaine infusions [3]
Non opioid ( non steroidal anti inflammatory drugs-NSAIDs ) analgesics NSAIDs produce pain relief by inhibition of cyclooxygenase (COX 1 and COX 2), which in turn reduce the level of prostaglandins which are known to mediate inflammation and increase pain sensations and swelling through inflammatory mechanisms. Use in patients with mild to moderate pain. Often these are given orally. Eg: Ibuprofen, Naproxen, COX 2 inhibitors such as celecoxib [4]
References
  1. CIMINO F, Volk BS., et al. Anterior cruciate ligament injury: diagnosis, management, and prevention. American Family Physician. October 2010, vol.82(8). 917-922 [viewed 5 March 2014]. Available from: http://www.aafp.org/afp/2010/1015/p917.html
  2. SPINDLER KP, Wright RW. Clinical practice. Anterior cruciate ligament tear. New England Journal of Medicine. April 2008, vol.359(20). 2135–2142 [viewed 5 March 2014]. Available from: http://www.nejm.org/doi/full/10.1056/NEJMc082471#t=article DOI: 10.1056/NEJMc082471
  3. ALFORD JW, Fadale PD. Evaluation of postoperative bupivacaine infusion for pain management after anterior cruciate ligament reconstruction. Arthroscopy. October 2003, vol.19(8). 855-61 [viewed 7 March 2014]. Available from: http://www.ncbi.nlm.nih.gov/pubmed/14551548
  4. R. LANCE SNYDER, Eric C. McCarty. Practical Orthopaedic Sports Medicine & Arthroscopy. 1st Edition. Ligament injury and pain management. 34.4. 2007 [viewed 7 March 2014]. Available from: http://www.msdlatinamerica.com/ebooks/PracticalOrthopaedicSportsMedicineArthrocopy/sid468032.html

Management - Specific Treatments

Fact Explanation
Conservative management - physical therapy Considered in elderly patients or less active athletes, to maintain range of motion and develop quadriceps strength. [1],[2]
Arthroscopy Arthroscopy considered in patients who are poor candidates for reconstruction - to debride the remaining stump to increase motion. [1],[2]
Surgical intervention - ACL reconstruction Indicated if the patient has sensation of instability in normal activities of daily living and for patients who want to return to high level of activity. ACL reconstruction is recommended rather than repair, as repair is no better than non operative management. [1],[2]
Extensive structured rehabilitation 10 - 12 week intensive schedule of strength building activities. Who undergo surgery must commit to appropriate rehabilitation for best out come. [1]
Prevention Specific proprioceptive and neuromuscular training exercises to improve knee stability. Use proper techniques when playing sports or exercising. [1]
References
  1. CIMINO F, Volk BS., et al. Anterior cruciate ligament injury: diagnosis, management, and prevention. American Family Physician. October 2010, vol.82(8). 917-922 [viewed 5 March 2014]. Available from: http://www.aafp.org/afp/2010/1015/p917.html
  2. SPINDLER KP, Wright RW. Clinical practice. Anterior cruciate ligament tear. New England Journal of Medicine. April 2008, vol.359(20). 2135–2142 [viewed 5 March 2014]. Available from: http://www.nejm.org/doi/full/10.1056/NEJMc082471#t=article DOI: 10.1056/NEJMc082471