Patellofemoral Unloader Knee Brace

Total Page:16

File Type:pdf, Size:1020Kb

Patellofemoral Unloader Knee Brace Patellofemoral Unloader Knee Brace A Major Qualifying Project Submitted to the Faculty of WORCESTER POLYTECHNIC INSTITUTE in partial fulfilment of the requirements for the Degree of Bachelor of Science Submitted By: James Junker Matthew Liberacki Brianna Owen Olivia Wisniewski Advisors Ambady, Sakthikumar Department of Biomedical Engineering Sabuncu, Ahmet C Department of Mechanical Engineering 1 Table of Contents Table of Contents Table of Contents .....................................................................................................................................2 Table of Figures .......................................................................................................................................4 Table of Tables .........................................................................................................................................6 Authorship .................................................................................................................................................7 Acknowledgements .................................................................................................................................8 Abstract ......................................................................................................................................................9 1. Introduction ................................................................................................................................... 10 2. Literature Review ........................................................................................................................ 11 2.1. Anatomy and Biomechanics of the Knee ........................................................................... 11 2.1.1. Bones .................................................................................................................................................................................. 11 2.1.2. Tendons and Ligaments ............................................................................................................................................. 13 2.1.3. Cartilage and Synovial Fluid..................................................................................................................................... 14 2.1.4. Contact Angle, Degree of Flexion, and Forces .................................................................................................. 15 2.1.5. Q-Angle .............................................................................................................................................................................. 16 2.2. Complications of the Patella and Injuries ................................................................... 17 2.2.1. Subluxation and Dislocation .................................................................................................................................... 18 2.2.2. Patella Tendonitis and Patellofemoral Pain Syndrome ............................................................................... 19 2.3 Patellofemoral Arthritis ................................................................................................... 20 2.3.1 Pathophysiology .............................................................................................................. 20 2.3. Current Treatments............................................................................................................ 21 2.4. Benefits and Limitations ................................................................................................... 24 3. Project Strategy ............................................................................................................................ 26 3.1. Initial Client Statement ..................................................................................................... 26 3.2. Revised Client Statement .................................................................................................. 26 3.3. Objectives & Constraints .................................................................................................. 27 3.4. Project Approach ................................................................................................................. 27 4. Design Process .............................................................................................................................. 28 4.1. Needs Analysis ...................................................................................................................... 28 4.1.1. Stakeholder Groups ..................................................................................................................................................... 28 4.1.2. Stakeholder Interviews .............................................................................................................................................. 29 4.1.3. Needs Statement ........................................................................................................................................................... 31 4.2. Design Requirements, Functions (Specifications) ................................................... 32 4.3. Important Industry Standards ....................................................................................... 34 2 4.4. Additional Considerations ............................................................................................... 35 4.4.1. Economics .......................................................................................................................... 35 4.4.2. Environmental Impact ................................................................................................... 35 4.4.3. Societal Influence ............................................................................................................ 35 4.4.4. Political Ramifications .................................................................................................. 35 4.4.5. Ethical Concerns .............................................................................................................. 36 4.4.6. Health and Safety Issues ............................................................................................... 36 4.4.7. Manufacturability ........................................................................................................... 36 4.4.8. Sustainability .................................................................................................................... 36 4.5. Conceptual Designs............................................................................................................. 36 4.6. Design Selection ................................................................................................................... 39 4.7. Modeling ................................................................................................................................. 42 4.7.1. Conceptual Design Selection and Rationale ...................................................................................................... 42 4.7.2. CAD History ..................................................................................................................................................................... 44 4.7.3. Design Rationale ............................................................................................................................................................ 48 4.7.4. Final Design Function ................................................................................................................................................. 49 4.8. Test Methods and Traceability ....................................................................................... 52 4.8.1. Test Methods ................................................................................................................................................................... 52 4.8.2. Traceability ...................................................................................................................................................................... 54 5. Verification and Validation ....................................................................................................... 55 5.1. Tensile Wire Test................................................................................................................................................................ 55 5.2. Dimension Test.................................................................................................................................................................... 57 5.3. Flexion Test ........................................................................................................................................................................... 58 5.4. CT Test .................................................................................................................................................................................... 58 5.5. Kinematic Motion Tracking ........................................................................................................................................... 61 5.6. FujiFilm ................................................................................................................................................................................... 67 5.7. C-Clamp Test .......................................................................................................................................................................
Recommended publications
  • Triple Dislocation Around the Knee Joint – a Case Report
    ical C lin as Chew et al., J Clin Case Rep 2019, 9:9 C e f R o l e a p n o r r t u s o J Journal of Clinical Case Reports ISSN: 2165-7920 Case Report Open Access Triple Dislocation around the Knee Joint – A Case Report Chew E1, Sharma A2 and Gupte C2 1Epsom and St Helier NHS Trust, Dorking Road, Epsom KT18 7EG, UK 2Imperial College Healthcare NHS Trust, South Wharf Road, Paddington, London W2 1NY, UK Abstract Dislocation of the knee is a serious and potentially limb threatening injury. There are 3 types of dislocation around the knee joint: patellofemoral, tibiofemoral and tibiofibular. Tibiofemoral dislocation is the variant that is deemed the most serious, with a higher risk of compromise to the popliteal artery and common peroneal nerve. Although simultaneous dislocations of two types have been described, there has been no such description of all three types occurring simultaneously. In this case we present a case of simultaneous dislocations of all 3 articulations around the knee. Diagnosis was achieved with clinical examination, plain films, CT and MRI scans. Management consisted of initial surgical debridement and reduction with stabilisation of the affected joints. Keywords: Knee; Dislocation; Trauma; Orthopaedic Surgery was unaffected and maintained its normal motor and sensory function throughout. She was then transferred by air ambulance to our specialist Introduction knee trauma unit where she underwent repeat secondary survey and The knee is a synovial joint formed by the articulations of the patella, radiological investigations including, MRI and CT. femur and tibia.
    [Show full text]
  • Diagnosis and Treatment of Multiligament Knee Injury: State of the Art Gilbert Moatshe,1,2,3 Jorge Chahla,2,4 Robert F Laprade,2,5 Lars Engebretsen1,3
    Journal of ISAKOS: Joint Disorders & Orthopaedic Sports Medicine Publish Ahead of Print, published on March 8, 2017 as doi:10.1136/jisakos-2016-000072 State of the Art J ISAKOS: first published as 10.1136/jisakos-2016-000072 on 8 March 2017. Downloaded from Diagnosis and treatment of multiligament knee injury: state of the art Gilbert Moatshe,1,2,3 Jorge Chahla,2,4 Robert F LaPrade,2,5 Lars Engebretsen1,3 1Oslo University Hospital and ABSTRact diagnostic workup and treatment plan is mandatory University of Oslo, Oslo, Norway when dealing with these injuries. The purpose of 2 Multiligament knee injuries constitute a complex and Steadman Philippon Research this article is to review specific focused principles Institute, Vail, Colorado, USA challenging entity, not only because of the diagnosis 3OSTRC, The Norwegian School and reconstruction procedure itself, but also because of of multiligament knee injuries, classification, diag- of Sports Sciences, Oslo, Norway the rehabilitation programme after the index procedure. nosis, treatment options and rehabilitation guide- 4Hospital Britanico de Buenos A high level of suspicion and a comprehensive clinical lines for addressing these complex injuries. Key Aires, Buenos Aires, Argentina and radiographic examination are required to identify information and articles on these injuries can be 5The Steadman Clinic, Vail, Colorado, USA all injured structures. Concomitant meniscal, chondral found in box 1 and box 2 respectively. and nerve injuries are common in multiligament injuries Correspondence to necessitating a detailed evaluation. Stress radiographs Classification Dr Robert F LaPrade, The are valuable in evaluating patients preoperatively Schenck described the most widely used classifica- Steadman Philippon Research and postoperatively.
    [Show full text]
  • Management of Knee Dislocation Prior to Ligament Reconstruction: What Is the Current Evidence? Update of a Universal Treatment Algorithm
    European Journal of Orthopaedic Surgery & Traumatology https://doi.org/10.1007/s00590-018-2148-4 GENERAL REVIEW • KNEE - BIOMECHANICS Management of knee dislocation prior to ligament reconstruction: What is the current evidence? Update of a universal treatment algorithm Alexander Maslaris1 · Olaf Brinkmann1 · Matthias Bungartz1 · Christian Krettek2 · Michael Jagodzinski2 · Emmanouil Liodakis2 Received: 25 August 2017 / Accepted: 3 February 2018 © Springer-Verlag France SAS, part of Springer Nature 2018 Abstract Traumatic knee dislocation is a rare but potentially limb-threatening injury. Thus proper initial diagnosis and treatment up to final ligament reconstruction are extremely important and a precondition to successful outcomes. Reports suggest that evidence-based systematic approaches lead to better results. Because of the complexity of this injury and the inhomogeneity of related literature, there are still various controversies and knowledge gaps regarding decision-making and step-sequencing in the treatment of acute multi-ligament knee injuries and knee dislocations. The use of ankle-brachial index, routine or selective angiography, braces, joint-spanning or dynamic external fixation, and the necessity of initial ligament re-fixation during acute surgery constitutes current topics of a scholarly debate. The aim of this article was to provide a comprehensive literature review bringing light into some important aspects about the initial treatment of knee dislocation (vascular injury, neural injury, immobilization techniques) and finally develop an accurate data-based universal algorithm, enabling attending physicians to become more acquainted with the management of acute knee dislocation. Keywords Knee dislocation · MLKI · Initial management · Protocol · Vascular injury · Nerve injury · Immobilization · Fixator · Brace · Cast Introduction Traumatic knee dislocation (KD) is a rare injury, reach- ing incidences between 0.001% of general population and 0.072% of orthopaedic traumata [1–6].
    [Show full text]
  • The Acutely Dislocated Knee: Evaluation and Management
    The Acutely Dislocated Knee: Evaluation and Management Jeffrey A. Rihn, MD, Peter S. Cha, MD, Yram J. Groff, MD, and Christopher D. Harner, MD 02/25/2021 on BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3i3D0OdRyi7TvSFl4Cf3VC4/OAVpDDa8KKGKV0Ymy+78= by http://journals.lww.com/jaaos from Downloaded Abstract Downloaded Acute knee dislocations are uncommon orthopaedic injuries. Because they often spon- (within 3 weeks of injury).6,8,13,14 Most taneously reduce before initial evaluation, the true incidence is unknown. Dislo- of the principles of evaluation and from http://journals.lww.com/jaaos cation involves injury to multiple ligaments of the knee, resulting in multidirec- management of the patient with an tional instability. Associated meniscal, osteochondral, and neurovascular injuries acutely dislocated knee are well es- are often present and can complicate management. The substantial risk of associ- tablished;15 recent advances have cen- ated vascular injury mandates that vascular integrity be confirmed by angiography tered on improvements in surgical in all suspected knee dislocations. Evaluation and initial management must be per- technique. by BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3i3D0OdRyi7TvSFl4Cf3VC4/OAVpDDa8KKGKV0Ymy+78= formed expeditiously to prevent limb-threatening complications. Definitive manage- ment of acute knee dislocation remains a matter of debate; however, surgical recon- struction or repair of all ligamentous injuries likely can help in achieving the return Classification
    [Show full text]
  • Leg Problems in Athletes
    ACMS Team Physician CourseSan AntonioFeb 2015 LEG PROBLEMS IN ATHLETES Marlene DeMaio, MD Prof, Dept of Orthopaedic Surgery, Marshall University VAMC Huntington, WV LEG PROBLEMS • LIMB THREATENING Approach – AcuteEmergency treatment – ChronicUrgent workup and treatment S1.totalprosports.com • NOT LIMB THREATENING Approach – Usually chronic – Systematic work up Edc2.healthtap.com – Comprehensive treatment Limb Threatening Leg Disorders • Loss of oxygenation – Vascular compromise – Amputation – Crush Injury – Acute compartment syndrome • Vascular compromise – NEVER ASSUME ARTERIAL SPASM – Vessel compression or injury (tear, laceration) • From bone fragment or bone displacement • Associated with KNEE dislocation Limb Threatening Leg Problems EXTREME SPORTS – NO VEHICLES • Jumpers – Bungee jumpers – Helo skiers – Parachuters • Skate boarders • Skiers • Parasailers INJURY COMBINATIONS • Any lower extremity fracture → acute compartment syndrome • Mechanism of injury • Other injuries • Immobilization • Compressive Dressings Injury Combinations – Medial tibial plateau fractures → knee dislocation – Femoral shaft fracture → knee dislocation (Giannoudis, J Ortho Trauma 2005) www.trauma.org Knee Dislocation IMMEDIATEMENT ASSESSMENT: Vascular status TREATMENT: Reduce and stabilize (Knee immobilizer) Restore blood flow Manage compartment syndrome BEWARE: posterolateral dislocations Photo from C. Roberts, MD Limb Threatening Leg Problems • Acute compartment syndrome – Multiple trauma versus isolated injury – ATLS • Even for isolated trauma • ABC’s
    [Show full text]
  • Rehabilitation Guidelines for Knee Multi-Ligament Repair/Reconstruction
    UW HEALTH SPORTS REHABILITATION Rehabilitation Guidelines for Knee Multi-Ligament Repair/Reconstruction The knee joint is comprised of an A B articulation of three bones: the femur Medial (thigh bone), tibia (shin bone), Collateral Ligament Lateral and patella (knee cap). The femur (MCL) Collateral has a medial (inside) and a lateral Ligament (outside) condyle that forms a radial (LCL) or rounded bottom that comes together, forming a trochlear groove for the patella to move. The medial and lateral condyle sit on top of the Fat LM Fat Pad tibia, which has a flat surface called Pad MM the tibial plateau. The knee also is comprised of two Fibula menisci, which are fibro-cartilaginous structures and each meniscus Figure 1 a: Medial or inner view of the knee showing the medial collateral ligament, is thinner towards the center of b: Lateral or outer view of the knee showing the lateral collateral ligament. the knee and thicker toward the Image property of Primal Pictures, Ltd., primalpictures.com. Use of this image without authorization from Primal Pictures, Ltd. is prohibited. periphery of the knee, giving it a wedge-shaped appearance. The Femur medial meniscus forms a “c” shape and is located between the medial ACL femoral condyle and the medial ACL LCL aspect of the tibia. The lateral meniscus forms an oval shape and is PCL located between the lateral femoral condyle and the lateral aspect of the MM LM tibia. The menisci act to improve stability between the tibia and the Menisci MCL Tibia femur secondary to its wedge shape that acts to limit translation.
    [Show full text]
  • ACR Appropriateness Criteria® Acute Trauma to the Knee
    Revised 2019 American College of Radiology ACR Appropriateness Criteria® Acute Trauma to the Knee Variant 1: Adult or child 5 years of age or older. Fall or acute twisting trauma to the knee. No focal tenderness, no effusion, able to walk. Initial imaging. Procedure Appropriateness Category Relative Radiation Level Radiography knee May Be Appropriate ☢ Bone scan with SPECT or SPECT/CT knee Usually Not Appropriate ☢☢☢ CT knee with IV contrast Usually Not Appropriate ☢ CT knee without and with IV contrast Usually Not Appropriate ☢ CT knee without IV contrast Usually Not Appropriate ☢ MR arthrography knee Usually Not Appropriate O MRA knee without and with IV contrast Usually Not Appropriate O MRA knee without IV contrast Usually Not Appropriate O MRI knee without and with IV contrast Usually Not Appropriate O MRI knee without IV contrast Usually Not Appropriate O US knee Usually Not Appropriate O Variant 2: Adult or child 5 years of age or older. Fall or acute twisting trauma to the knee. One or more of the following: focal tenderness, effusion, inability to bear weight. Initial imaging. Procedure Appropriateness Category Relative Radiation Level Radiography knee Usually Appropriate ☢ Bone scan with SPECT or SPECT/CT knee Usually Not Appropriate ☢☢☢ CT knee with IV contrast Usually Not Appropriate ☢ CT knee without and with IV contrast Usually Not Appropriate ☢ CT knee without IV contrast Usually Not Appropriate ☢ MR arthrography knee Usually Not Appropriate O MRA knee without and with IV contrast Usually Not Appropriate O MRA knee without IV contrast Usually Not Appropriate O MRI knee without and with IV contrast Usually Not Appropriate O MRI knee without IV contrast Usually Not Appropriate O US knee Usually Not Appropriate O ACR Appropriateness Criteria® 1 Acute Trauma to the Knee Variant 3: Adult or skeletally mature child.
    [Show full text]
  • BOOKS ATHLETIC HEAD and SPINE INJURIES SHOULDER
    BOOKS Micheli: Oxford Textbook of Sports Medicine -excellent overview of all conditions and diagnosis. limited surgical technique. Garret: Principles and Practice of Sports Medicine -Classic surgeons text written by former UNC chair and Duke Sport’s Surgeon Snyder: Shoulder Arthroscopy -bread and butter, first generation shoulder scoping Jackson: Reconstructive Knee Surgeries -older, but classic for open surgery of knee. Andrews: Arthroscopic Surgery -classic "old school" intro to Arthroscopy (all joints) OKU: Sports, General, Shoulder & Elbow -essential for boards ATHLETIC HEAD and SPINE INJURIES 1. On-the-Field Management of Athletic Head Injuries. Pierre Durand, Jr and Gregory J. Adamson. J Am Acad Orthop Surg May/June 2004; 12:191-195. 6. Concussion in Sports. Am J Sports Med. 1999 Sep-Oct;27(5):676-87.E. Wojtys, D. Horda, G. Landry, et al. SHOULDER Rotator Cuff 18. Predictors of failure of nonoperative treatment of chronic, symptomatic, full-thickness rotator cuff tears. Dunn WR, et al. J Shoulder Elbow Surg. 2016 Aug;25(8):1303-11. Patient’s perception of the effectiveness of PT predicts failure of conservative therapy. 27. Clinical and structural outcomes after arthroscopic single-row versus double-row rotator cuff repair: a systematic review and meta-analysis of level I randomized clinical trials.Millett PJ, Warth RJ, Dornan GJ, Lee JT, Spiegl UJ. J Shoulder Elbow Surg. 2014 Apr;23(4):586-97. Single- row repairs resulted in significantly higher re-tear rates compared with double-row repairs, especially with regard to partial-thickness re-tears. 39. Clinical results of arthroscopic superior capsule reconstruction for irreparable rotator cuff tears.
    [Show full text]
  • Chronic Knee Dislocation Treated with a Taylor Spatial Frame
    SAOJ Winter 2012_Orthopaedics Vol3 No4 2012/05/22 4:38 PM Page 61 CASE REPORT AND REVIEW OF THE LITERATURE SA ORTHOPAEDIC JOURNAL Winter 2012 | Vol 11 • No 2 / Page 61 CASE REPORTAND REVIEWOF THE LITER ATURE Chronic knee dislocation treated with a Taylor Spatial Frame N Ferreira, BSc, MBChB, HDip Orth (SA), FC Orth (SA), MMed (Orth) LC Marais MBChB, FCS (Orth) (SA), MMed (Orth), CIME Tumour, Sepsis and Reconstruction Unit, Department of Orthopaedic Surgery, Grey’s Hospital, University of KwaZulu-Natal, Pietermaritzburg, South Africa Reprint requests: Dr N Ferreira Department of Orthopaedic Surgery Grey’s Hospital Private bag X9001 3201 Pietermaritzburg Email: [email protected] Tel: +27 033 897 3299 Fax: +27 33 897 3409 Abstract Chronic knee dislocations are fortunately not seen commonly, but when these injuries do present, they are typi- cally a source of severe functional impairment to the patient. Surgical management may harbour further compli- cations due to the extensive soft tissue release that is required, and the fact that significant deformities are cor- rected acutely. We report on a 32-year-old, HIV-1 infected, female patient 20 months after a dislocation of the left knee. Due to the extent of her flexion contracture, she was unable to walk unaided. A Taylor Spatial Frame was applied across the knee, and gradual reduction of the dislocation, with correction of the knee flexion deformity, was performed over a period of 26 days. The final result produced a stable, ankylosed knee that allowed weight bearing without the need for any walking aids. No complications attributed to the reduc- tion or the fixator was experienced, and no additional surgeries were required.
    [Show full text]
  • Acute Traumatic Patellar Tendon Rupture: Early and Late Results Of
    Orthopaedics & Traumatology: Surgery & Research 101 (2015) 307–311 View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Available online at ScienceDirect www.sciencedirect.com Original article Acute traumatic patellar tendon rupture: Early and late results of surgical treatment of 38 cases ∗ A. Roudet , M. Boudissa , C. Chaussard , B. Rubens-Duval , D. Saragaglia Clinique Universitaire de Chirurgie Orthopédique et de Traumatologie du Sport, CHU de Grenoble, Hôpital Sud, avenue de Kimberley, BP 338, 38130 Echirolles, France a r t i c l e i n f o a b s t r a c t Article history: Introduction: Acute patellar tendon rupture is easy to diagnose but is still often overlooked. The aim of Received 22 August 2014 this study was to assess early and late results of surgical treatment of acute patellar tendon rupture. Our Accepted 23 December 2014 hypothesis was that functional outcome is satisfactory. Methods: A retrospective study included 38 knees in 37 patients (4 female, 33 male). Mean age was Keywords: 42.6 ± 9.9 years (range, 23–81 years). Lesions comprised 15 tendon body ruptures, 20 avulsions from the Patellar tendon tip of the patella and 3 avulsions from the anterior tibial tuberosity. Tendon repair was protected in Acute rupture more than 95% of cases by a reinforcement frame: hamstring (21 cases), synthetic ligament (12 cases) Surgical repair or metallic wire (3 cases). Results were evaluated in 2 steps: on patient files at a mean follow-up of 7.1 months (range, 3–24 months) to assess complications and early functional and radiological results; and by phone at a mean follow-up of 9.3 years (range, 19–229 months) in order to assess long-term functional outcome on Lysholm score and patient satisfaction.
    [Show full text]
  • Congenital Knee Dislocation in a 49,XXXXY Boy J Med Genet: First Published As 10.1136/Jmg.32.4.309 on 1 April 1995
    _JMed Genet 1995;32:309-311 309 Congenital knee dislocation in a 49,XXXXY boy J Med Genet: first published as 10.1136/jmg.32.4.309 on 1 April 1995. Downloaded from R H Sijmons, A J van Essen, J D Visser, M Iprenburg, G F Nelck, M L Vos-Bender, B de Jong Abstract hands. The diagnosis Larsen syndrome was We report on a 12 year old mentally re- suggested at that time. The dislocations of the tarded boy who presented at birth with knees and right hip were treated conservatively. bilateral knee dislocations, dislocation of A knee-ankle-foot brace was prescribed for the the right hip, and general joint laxity. instability of both knees. Milestones in psy- Cytogenetic studies showed a 49,XXXXY chomotor development were delayed. He stood karyotype. Hyperlaxity of joints is known at the age of 15 months; however, subsequent to occur in 49,XXXXY patients, but con- motor development, supported by the brace, genital knee dislocation has not been re- was adequate. At the age of 2 he still could not ported. Rarely in 49,XXXXY and 49, speak more than two words. At the age of 5 XXXXX syndromes Larsen-like features his IQ was estimated to be between 50 and may be seen. Patients with congenital joint 60, with a relatively severe expressive speech dislocation or laxity, combined with other deficit. His behaviour was described as shy and malformations, especially if psychomotor withdrawn. development is delayed, should be At the age of 11 the boy was referred for karyotyped to exclude chromosomal clinical genetic evaluation of the diagnosis and abnormalities.
    [Show full text]
  • Treatment of Acute Traumatic Knee Dislocations Angelo J
    Treatment of Acute Traumatic Knee Dislocations Angelo J. Colosimo, MD Head Orthopaedic Surgeon University of Cincinnati Athletics Director of Sports Medicine University of Cincinnati Medical Center Associate Professor of UC College of Medicine Medical Director Holmes Sports Medicine Knee Dislocations • Wide spectrum of severity and associated injuries • Often secondary to high-energy trauma • Most commonly reported cause is MVA • Athletic injuries are the second most common cause of knee dislocations Knee Dislocations • High-Energy – Usually MVA or fall from a height – Dashboard injury common – Forced Hyperextension athletic injury – Athletic injuries • Low-Energy – Generally from a rotational component – Morbid obesity is a rick factor Knee Dislocation Video Knee Dislocation Classification • Based upon the position of the tibia on the femur: – Anterior – Posterior – Lateral – Medial – Rotary Anterior Knee Dislocations • Most common dislocation (30-50%) • Frequent arterial injury (intimal tear due to traction) • Hyper-extension most common mechanism of injury Posterior Dislocation • Second Most common (25%) • Due to axial load to flexed knee (dashboard injury) • Highest rate of complete tear of popliteal artery Lateral Dislocation • 13% of knee dislocations • Due to valgus force • Highest rate of peroneal nerve injury • Involves ACL and PCL tears Medial Dislocations • Varus force • Usually disrupts PLC and PCL Rotational Dislocation • Posterolateral is most common rotational dislocation • Usually irreducible Presentation • Symptoms: –
    [Show full text]