8/4/2015
Knee Injuries and Immobilization
Disclosures
I have nothing to disclose.
Kristy M. Smith, M.D. DMC Sinai-Grace Hospital Detroit Medical Center Sports Medicine Associate Team Physician Detroit Pistons
Objectives
Common Injuries of the Knee
Mechanism of Injury
Incidence
6.6 million knee injuries presented to the ED between 1999-2008
Initial ED Management and required images
What types of injuries require immobilization
Incidence
2.5 million sports related knee injuries 2.29 knee injuries per 1000 Ages 15-24 had highest rate of injury 42.1% of those seen diagnosed with strain/sprain
Knee Anatomy
Males more likely to suffer basketball related injuries Patient’s over 65 years of age
Injury via stairs
Ramps Landings Floors
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Anatomy of the knee
Who needs a knee immobilizer?
Quadriceps Tendon Ruptures
Quadriceps Tendon Rupture
More common that patellar tendon ruptures
More common in males >40 years of age
Generally in 6th and 7th decades of life
Mechanism via eccentric loading
Risk factors
Prolonged Steroid Use Rheumatoid Arthritis DM Renal Failure
Quadriceps Tendon Rupture
Physical Exam:
Palpable deformity within superior pole of the patella
Large Hemarthrosis
Inability to ambulate
Complete rupture
Inability to perform a straight leg raise
Unable to perform knee extension against resistance
Quadriceps Tendon Rupture Normal Lateral
Patella Baja
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Quadriceps Tendon Rupture
Management Orthopaedic Consultation Operative Intervention versus Conservative Treatment Determination of partial versus complete rupture Generally operative repair within 7 days of injury Conservative treatment for those who are poor surgical candidates or partial tears with intact extensor mechanisms. Advanced imaging MRI if partial tear is considered Ultrasound
Physical Exam
Rupture occurs most often with knee in flexed position Often occurs with a sudden rapid contraction of the quad muscle
Most Common in 3rd to 4th decade of life Males > Females Less common than quadriceps tendon ruptures Risk Factors DM SLE Rheumatoid Arthritis Chronic Renal Disease
Patellar Tendon Ruptures
Mechanism of Injury
IMMOBILIZE IN EXTENTION!!!!
Patellar Tendon Ruptures
Patellar Tendon Ruptures
Joint Effusion Elevation of the patella with respect to the femur Palpable gap at the inferior pole of the patella Inability to perform a straight leg raise Inability to extend the knee
Patellar Tendon Ruptures Normal Lateral
Patella Alta
Imaging Standard knee radiographs Ultrasound MRI Most sensitive of the imaging modalities Will distinguish incomplete from complete rupture Ability to determine extent of other soft tissue injuries
Patellar Tendon Rupture
Orthopaedic Consultation IMMOBILIZATION IN EXTENTION!!!!
Progressive weight-bearing
Non-operative Treatment
Partial rupture Intact extensor mechanism Early protected range of motion exercises
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Patellar Dislocation & Subluxation
Acute Injuries Often direct impact injuries
Patellar Dislocation & Subluxation
Chronic Frequent episodes Limb Malalignment Occurs more in women
Stability of the patella
Medial Patellofemoral ligament (MPFL)
Provides passive stability
Dynamic stability provided via the vastus medialis
Often occurs in the 2nd and 3rd decades of life
Patellar Dislocation & Subluxation
Acute Patellar dislocation
Large hemarthrosis Tenderness to palpation over the MPFL Visible deformity
Closed Reduction Hip flexion Medial patellar stress with extension of the knee
Patellar Dislocation & Subluxation
Post-reduction radiographs
AP, Lateral, Merchant views
Evaluate for patella alta Patellar osteochondral fracture If radiographs indeterminate consider
Patellar Dislocation & Subluxation
Treatment
Orthopaedic Consultation
Non-operative treatment
CT MRI
Patellar Fractures IMMOBLIZE!!!!!
IMMOBLIZE!!!!!
Appropriate in patients with no evidence of osteochondral fracture
IMMOBILIZE
IN EXTENSION!
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Patellar Fractures
What about ACL, PCL, MCL, LCL?
In Summary
Questions?
Knee Immobilizers are initial method of immobilization for
Quadriceps Tendon Rupture
Patellar Tendon Ruptures
Patellar Dislocation/Subluxation
Patellar Fractures
Early Orthopedic Consultation
References
Redfern J, Kamath G, Burks R. Anatomical confirmation of the use of radiographic landmarks in medial patellofemoral ligament reconstruction. Am J Sports Med. 2010 Feb;38(2):293-7 Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012 Toritsuka Y, Horibe S, Hiro-Oka A, Mitsuoka T, Nakamura N. Medial marginal fracture of the patella following patellar dislocation. Knee. 2007 Dec;14(6):429-33 Dejour H, Walch G, Nove-Josserand L, Guier C. Factors of patellar instability: an anatomic radiographic study. Knee Surg Sports Traumatol Arthrosc. 1994;2(1):19-26 Fithian DC, Paxton EW, Stone ML, Silva P, Davis DK, Elias DA, White LM. Epidemiology and natural history of acute patellar dislocation.AJSM 2004;32:1114-1121 Wheeles III CR. Wheeless’ Textbook of Orthopaedics- Duke Orthopaedics 2008 Orthopaedic Knowledge Update: Sports Medicine 3. 9, Orthopaedic Knowledge Update 9, Garrick JG (Editor). Published by American Academy Orthopaedic Surgeons, Rosemont IL. Copyright 2004 Gage BE, McIlvain NM, Collins CL, Fields SK, Comstock RD. Epidemiology of 6.6 million knee injuries presenting to United States emergency departments from 1999 through 2008. Acad Emerg Med. 2012 Apr;19(4):378-85. doi: 10.1111/j.1553-2712.2012.01315.x.
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