Snapshot A 21-year-old man presents to the emergency department for severe pain in the right knee. A few hours prior to presentation, an opposing football player hits his leg from his right side. Afterwards, he felt a "pop" sound that was followed by severe knee pain and a sensation of knee instability. On physical exam, there is anterior translation of the proximal tibia when pulled as the patient has the knee flexed at 90° and supine. Ice is applied to the knee and ibuprofen is prescribed. Orthopedic surgery is consulted to evaluate if ligamental reconstruction is needed. Introduction Clinical definition injury in the form of tear or rupture affecting the anterior cruciate ligament (ACL) in the knee Associated conditions unhappy triad which consists of injury to the ACL medial collateral ligament medial meniscus Prognosis The majority of athletes are able to return to their sports activities with ACL reconstruction Epidemiology Incidence non-contact ACL injuries are more common Demographics more common in female athletes Risk factors sports (e.g., football, soccer, skiers, and basketball) motor vehicle accidents ETIOLOGY Pathoanatomy Pathology contact mechanisms injury that causes hyperextension or valgus deformation of the knee e.g., football injury high-speed motor vehicle accident non-contact mechanisms changing direction, pivoting, or landing that leads to rotation or valgus stress of the knee after sudden deceleration Normal anatomy the ACL course originates in the posteromedial aspect of the lateral femoral condyle reaches the anteromedial aspect of the tibia the ACL plays an important role in knee stability it controls anterior translation of the tibia it also restrains against tibial rotation, varus, and valgus stress Presentation Symptoms feeling a "pop" in the knee thereafter, there is acute swelling and pain instability or "giving out" knee Physical exam anterior drawer test the proximal tibia is anteriorly pulled while the patient is supine and the knee is flexed at 90 degrees if there is anterior translation then the test is positive Lachman test the proximal tibia is anteriorly pulled with one hand, while the other hand stabilizes the distal femur while the knee is flexed at 30 degrees hemarthrosis Imaging Magnetic resonance imaging (MRI) indication an imaging modality that can confirm the diagnosis if reconstruction is a possibility or to identify concomitant knee pathology Studies Making the diagnosis can be made based on typical clinical presentation alone can be confirmed by MRI or knee arthroscopy Differential Meniscal tear differentiating factor patients can have a positive Thessaly test McMurray test Apley test Posterior collateral ligament (PCL) injury differentiating factor patients can have a positive posterior drawer test Treatment Conservative rest, ice, compression, and elevation (RICE) therapy indication management to reduce pain, edema, and hemarthrosis in the acute stage of the injury nonsteroidal anti-inflammatory drugs are typically added Operative surgical reconstruction indications performed in young and active patients with high demand sports or jobs significant knee instability such as injuries affecting multiple knee structures (e.g., unhappy triad) Complications Osteoarthritis Arthrosis Sports disability
QUESTIONS 1 of 1 1 Previous Next (M2.OR.17.4799) A 25-year-old male presents to his primary care physician for pain in his knee. The patient was in a wrestling match when his legs were grabbed from behind and he was taken to the floor. The patient states that the moment this impact happened, he felt a snapping and sudden pain in his knee. When the match ended and he stood back up, his knee felt unstable. Minutes later, his knee was swollen and painful. Since then, the patient claims that he has felt unstable bearing weight on the leg. The patient has no significant past medical history, and is currently taking a multivitamin and protein supplements. On physical exam you note a tender right knee, with erythema and an effusion. Which of the following is the most likely physical exam finding in this patient? QID: 109202 Type & Select Correct Answer 1 Laxity to valgus stress 0% (0/5) 2 Laxity to varus stress 0% (0/5) 3 Clicking and locking of the joint with motion 40% (2/5) 4 Anterior translation of the tibia relative to the femur 20% (1/5) 5 Posterior translation of the tibia relative to the femur 20% (1/5) M 6 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic
All Videos (4) Login to View Community Videos Login to View Community Videos Positive Anterior Drawer Test Chris Battista Orthopedics - Anterior Cruciate Ligament (ACL) Injury E 8/23/2015 161 views 0.0 (0) Login to View Community Videos Login to View Community Videos Lachman's test Chris Battista Orthopedics - Anterior Cruciate Ligament (ACL) Injury E 8/23/2015 171 views 5.0 (1) Login to View Community Videos Login to View Community Videos Pivot Shift Test - Intraoperative Orthopedics - Anterior Cruciate Ligament (ACL) Injury E 11/17/2012 67 views 0.0 (0) Orthopedics | Anterior Cruciate Ligament (ACL) Injury Orthopedics - Anterior Cruciate Ligament (ACL) Injury Listen Now 9:38 min 3 weeks ago 1 plays 0.0 (0) See More See Less