Defination Flashcards
Acetabular protrusio
- is the proximal and medial migration of the femoral head through the medial acetabular wall into the pelvis
Actin and Myosin
BCIS
- BCIS (Bone cement implantation syndrome) is characterized by a number of clinical features that may include hypoxia, hypotension, cardiac arrhythmias, increased pulmonary vascular resistance (PVR) and cardiac arrest.
- It is most commonly associated with, but is not restricted to, hip arthroplasty.
- It usually occurs at one of the five stages in the surgical procedure; femoral reaming, acetabular or femoral cement implantation, insertion of the prosthesis or joint reduction.
Biopsy
STIL DCH MN
- By Surgeon performing the definitive surgery
- TQ no Exsanguination
- In line of incision
- Longitudinal incision
- Direct approach
- Culture all biopsies and biopsy all cultures
- Homeostasis
- Meticulous suturing
- No Drains as possible
Bone cement
Powder Polymer
- Polymethyl methacrylate/co-polymer (PMMA)
- Initiator: Benzoyl peroxide (BPO)
- Radio-opacifier: Barium sulphate (BaSO4)/Zirconia (ZrO2)
- Antibiotics (e.g. Gentamycin)
Liquid Monomer
- Methyl methacrylate (MMA)
- Accelerator: N, N-Dimethyl para-toluidine (DMPT)/diMethyl para-toluidine (DMpt)
- Stabilizer: Hydroquinone
Polymethyl methacrylate is a man-made acrylic which composes of a liquid monomer and a powdered polymer and when mixed together causes an exothermic reaction to reach the final product.
- It produces mechanical interlocking on hardening
- essentially a grout that fills the space between implnant and bone to provide stability and fixation
- Cardiogenic shock - the heart is unable to generate sufficient cardiac output
- Neurogenic shock - hypotension and relative bradycardia from loss of sympathetic tone following
- spinal cord inury -
- Septic shock vs. hypovolemic shock
- the key variable to differentiate septic shock and hemorrhagic shock is that systemic vascular resistance is decreased with septic shock and increased with hypovolemic shock
Catastrophic Wear -
Refers to macroscopic premature failure of polyethylene (PE) due to excessive loading.
Primary variables that lead to catastrophic wear include
- PE thickness
- articular surface design
- kinematics
- PE sterilization
- PE machining
Clavicle fracture indication
Fracture-Specific
- Displacement > 2 cm
- Shortening > 2 cm
- Increasing comminution (>3 fragments)
- Segmental fractures
- Open fractures
- Impending open fractures with soft-tissue compromise
- Obvious clinical deformity (usually associated with displacement and shortening)
- Scapular malposition and winging at initial examination
Associated Injuries
- Vascular injury requiring repair
- Progressive neurologic deficit
- Ipsilateral upper extremity injuries/fractures
- Multiple ipsilateral upper rib fractures
- “Floating shoulder”
Bilateral clavicular fractures
Patient Factors
- Polytrauma with requirement for early upper extremity weight bearing/arm use
- Patient motivation for rapid return of function (e.g., elite sports or self-employed professional)
Clinical trial
- Identify a problem/interest to be studied – via literature search
- identify a gold standard to compare to Ask a question
- null hypothesis Design your study Define your population
- inclusion/exclusion criteria
- The methodology of the study
- Power analysis (statistician) for numbers required to able to draw statistically valid conclusions from your results
- Define outcome measures (valid and reproducible)
- Obtain ethics approval – COREC / local committee Register trial Conduct the trial
- Recruit your patients – randomise / double-blinded (masked) / stratification for confounding factors
- Collect your data Analyse your results (stats)
- Interpret your findings, write up your work and publish in peer-reviewed journals
CMT - Charcot-Marie-Tooth Disease, also known as peroneal muscular atrophy, is a hereditary motor sensory neuropathy (HMSN) that results in muscles weakness and sensory changes muscle weakness leads to cavovarus foot, scoliosis, and other orthopaedic conditions
HMSN Type I - abnormal myelin sheath protein is the basis of this degenerative neuropathy. results in a combination of motor and sensory disturbances. HSMN Type 2- intact myelin sheath with wallerian axonal degeneration that results in mild sensory and motor conduction velocities.
Consecutive infected THR
- This is a clinical governance emergency – set protocolled action plan is activated
- First priority is the appropriate further care of the patients infected – multidisciplinary team / barrier nursing / appropriate antibiotics Stop elective operating
- Clinical governance ladder - Inform clinical director, medical director, microbiologist, infection control nurse (set up an committee to investigate outbreak)
- Report to national level
- Perform a through investigation as to why this has happened and where in the pt pathway things have gone wrong.
- Look at preop assessment – screening Staff - ? Possible carriers Theatre suite – check laminar flow / instruments / drapes / gowns / masks Check the elective ward
Constraint
- defined as the effect of the elements of knee implant design that provides the stability needed to counteract forces about the knee after arthroplasty in the presence of a deficient soft-tissue envelope. Determining the amount of constraint necessary can be challenging.
Corrosion
Refers to the chemical dissolution of metal.
- Galvanic corrosion - dissimilar metals leads to electrochemical destruction in the presence of electrolyte.
- Crevice corrosion refers to corrosion occurring in confined spaces to which the access of the working fluid from the environment is limited.
- Fretting corrosion - a mode of destruction at the contact site from the relative micromotion of two materials or two components
Creep
The phenomenon of progressive deformation of metal in response to a constant force over an extended period of time
Crescent Frx: (Sacroiliac Fracture)
involves a combination of ligamentous injury at inferior portion of SI joint, and verticle fracture of the posterior ilium which extends thru iliac crest; - posterior superior iliac spine remain attached to the sacrum; - often occurs as a part of lateral compression fractures; frx often remains stable to vertical forces because sacrospinous and sarcrotuberous ligaments remain intact; - this fracture pattern needs to be distinguished from iliac fractures that extend from the iliac crest into the greater sciatic notch, sparing the sacroiliac joint; - these iliac fractures may be associated with gluteal vascular injuries;
Diathesis Heuston
Term coined by Hueston Disease starts
- early (<40, ?<50)
- Both Hands
- Radial Sided Involvement
- Family History
- Garrods Pads
Distal Humerus Physeal Separation
a distal humerus physeal separation is a traumatic fracture usually seen in children under the age of three and is often a birth fracture related to delivery. the fracture pattern should raise suspicion of child abuse. treatment is usually operative closed reduction and pinning. Mechanism vaginal delivery (birth fracture) cesarean section nonaccidental trauma rotational force / twisting
Dupuytrens Predictors of Outcome
- Age of patient
- Evidence of Diathesis
- Female Severity of Deformity at the PIPJ
- Smoking
Fibroproliferative disorder affecting the palmar and digtial fascia with the formation of pathological collagen cords causing a progressive flexion deformity
Early Appropriate Care
- Identifies major trauma patients and definitively treats the most time-critical orthopaedic injuries while minimizing the secondary inflammatory response, guided by laboratory parameters of adequate resuscitation popularized in 2013
- Parameters
- lactate of < 4.0 mmol/L
- pH ≥ 7.25
- base excess ≥ -5.5 mmol/L
- Optimal time of surgery goal is to definitively treat spine, pelvis, femur, and acetabulum fractures within 36 hours of injury
- Outcomes decreased delay to surgery decreased complication rates increased hospital revenues main reason for delay to treatment with implementation of this protocol was surgeon decision
Effective joint space
the space includes all periprosthetic regions that are accessible to the joint fluid and thus particulate debris, has been proposed as a mechanism for migration of particles.
Endochondral Ossification:
- Bone replaces a cartilage anlage (template). Osteoclasts remove the cartilage, and osteoblasts make the new bone matrix, which is then mineralized.
- Typical in long bones (except clavicle).
- Primary ossification centers (in shaft) typically develop in prenatal period.
- Secondary ossification centers occur at various times after birth, usually in the epiphysis.
- Longitudinal growth at the physis also occurs by enchondral ossifi cation.
- Also found in fracture callus
Enchondral bone formation occurs in
- longitudinal physeal growth
- embryonic long bone formation
- non-rigid fracture healing (secondary healing)
Endurance limit
defined as the maximal stress under which an object is immune to fatigue failure regardless of the number of cycles
Fatigue failure
Failure of a material
- secondary to repetitive loading
- above the endurance limit
- below the ultimate tensile strength
- depends on the magnitude of stress
- number of cycle
*
Fatigue failure
- to failure of a material with repetitive loading at stress levels below the ultimate tensile strength
- The endurance limit is defined as the stress at which the material can withstand 10 million cycles without experiencing fatigue failure.
- Clinically,
- Total hip replacements operate above the endurance limit,
- While total knee replacements operate at the endurance limit, especially the polyethylene component, predisposing the latter to fatigue failure.
Growth plate
R P M D C
5 separate zones which have a role in endochondral bone formation
- Resting or Reserve
- Proliferative
- Maturation
- Degenerative
- Calcification (last 3 = hypertrophic)
Miniaci method for frontal plane correction.
- Line 1 represents the planned Mikulicz line for the postoperative correction extending from the center of the hip through the center of the knee, past the ankle.
- Line 2 connects the osteotomy hinge point (H) with the center of the ankle.
- The H point was located on the medial cortex of the proximal tibia at the lower level of tibial tuberosity.
- With H point as the center and the length of line 2 as the radius, an angular arc is drawn from the center of the ankle to the intersection of line 1.
- Line 3 connects the H point with the intersection of line 1.
- The angle formed by lines 2 and 3 is the planned correction angle (A).
- (B) Angle A is now drawn on the prospective site of the osteotomy on the AP radiographs of the knee joint.
- The distance (d) of the two lines at the lateral cortex was measured as the osteotomy wedge base (magnification factor must be considered).
T Tubules
The 3 rockers of gait.
- 1st Rocker -
- the heel strikes the ground,
- he foot rotates around this, and the ankle joint axis to come to rest in the flat foot position.
- Contraction of the anterior compartment muscles* controls this motion.
- 2nd Rocker
- the tibia is brought “ up and over “ the talus, rotating around the ankle joint.
- The intrinsic muscles of the foot and tibialis posterior fire* to maintain a medial longitudinal arch
- The terminal portion of the second rocker signals the powerful triceps surae to fire.
- 3rd Rocker
- the ankle plantar flexes over a fixed forefoot (about the metatarsophalangeal joints) ending in toe-off, initiating the swing phase of gait.
