A dislocation of the knee ( tibiofemoral joint Tibiofemoral joint Knee Joint: Anatomy) is a rare injury but is important to recognize because of limb-threatening trauma. Knee dislocations (KDs) are emergent cases that require immediate reduction and evaluation of the neurovascular system. Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor includes precedent trauma, obvious deformity Deformity Examination of the Upper Limbs, effusion, ecchymosis Ecchymosis Extravasation of blood into the skin, resulting in a nonelevated, rounded or irregular, blue or purplish patch, larger than a petechia. Orbital Fractures, and possible signs of vascular injury to the popliteal artery Popliteal Artery The continuation of the femoral artery coursing through the popliteal fossa; it divides into the anterior and posterior tibial arteries. Popliteal Fossa: Anatomy. Management includes reduction of the dislocation, serial examinations for arterial perfusion, imaging of the vascular system, and orthopedic and vascular consultations.
Last updated: 29 Apr, 2022
A dislocation of the knee ( tibiofemoral joint Tibiofemoral joint Knee Joint: Anatomy) is a rare injury that is important to recognize due to the frequent association with vascular injury and associated risk of limb amputation Amputation An amputation is the separation of a portion of the limb or the entire limb from the body, along with the bone. Amputations are generally indicated for conditions that compromise the viability of the limb or promote the spread of a local process that could manifest systemically. Amputation. These are emergent cases that require immediate reduction and evaluation of the neurovascular system.
Knee dislocations (KDs) can be classified based on the position of the tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy in relation to the femur, etiology, or on the pattern of ligament tears (Schenck classification).
Classification based on the position of the tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy in relation to the femur:
The knee joint Knee joint The knee joint is made up of the articulations between the femur, tibia, and patella bones, and is one of the largest and most complex joints of the human body. The knee is classified as a synovial hinge joint, which primarily allows for flexion and extension with a more limited degree of translation and rotation. Knee Joint: Anatomy: bony structure and landmarks
Image by BioDigital, edited by LecturioClassification by etiology:
Schenck classification of KDs: based on pattern of ligament tears
Usually a high-energy mechanism of injury is required for multiple ligaments to fail in order for dislocation to occur.
Image displaying the menisci Menisci Meniscus Tear, ligaments, and bony surfaces and their relation to one another
Image by Lecturio. License: CC BY-NC-SA 4.0Image displaying the menisci Menisci Meniscus Tear and their relation with other articular surfaces that compose the knee joint Knee joint The knee joint is made up of the articulations between the femur, tibia, and patella bones, and is one of the largest and most complex joints of the human body. The knee is classified as a synovial hinge joint, which primarily allows for flexion and extension with a more limited degree of translation and rotation. Knee Joint: Anatomy
Image by BioDigital, edited by LecturioSupporting ligaments of the patellofemoral joint Patellofemoral Joint The articulation between the articular surface of the patella and the patellar surface of the femur. Knee Joint: Anatomy
Image by Lecturio. License: CC BY-NC-SA 4.0Posterior anatomy of the knee showing the relationship Relationship A connection, association, or involvement between 2 or more parties. Clinician–Patient Relationship between the popliteal artery Popliteal Artery The continuation of the femoral artery coursing through the popliteal fossa; it divides into the anterior and posterior tibial arteries. Popliteal Fossa: Anatomy and the tibial and common fibular nerves
Image by BioDigital, edited by LecturioKnee dislocations are an uncommon injury but require emergent evaluation and management secondary to the possibility of limb ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage, which may require surgical intervention to avoid amputation Amputation An amputation is the separation of a portion of the limb or the entire limb from the body, along with the bone. Amputations are generally indicated for conditions that compromise the viability of the limb or promote the spread of a local process that could manifest systemically. Amputation.
Posterior knee dislocation: Note the obvious deformity Deformity Examination of the Upper Limbs as the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy is displaced downward due to gravity.
Image: “Neglected irreducible posterolateral knee dislocation” by Department of Orthopaedics, Postgraduate Institute of Medical Education Medical education Conflict of Interest and Research Research Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. Conflict of Interest, Sector 12, Chandigarh – 160 012, India. License: CC BY 2.0The majority of complete KDs are clinically obvious with a history of significant trauma and gross deformity Deformity Examination of the Upper Limbs of the knee. Diagnosis is made clinically, although imaging studies may be indicated to confirm suspected vascular injury or fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures and/or for surgical planning.
Posterior knee dislocation seen on radiography before and after reduction with underlying knee osteoarthritis Osteoarthritis Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis
Image: “Posterior knee dislocation on X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests” by Department of Orthopaedics and Traumatology, Ankara Numune Training and Research Research Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. Conflict of Interest Hospital, 06100 Ankara, Turkey. License: CC BY 3.0Closed reduction Closed Reduction Radial Head Subluxation (Nursemaid’s Elbow) of a KD KD An acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. The principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities. Kawasaki Disease should not be delayed, especially in a limb with obvious vascular impairment. As these injuries are often high-energy trauma, evaluation for other life-threatening injuries is essential.
Operative repair of an irreducible posterolateral knee dislocation
Image: “Peroperative photograph” by Indian Journal of Orthopaedics. License: CC BY 4.0