Chapter 3 · MCQ Read Mode

Implantable Devices

The principal disadvantage of a mechanical prosthetic heart valve compared with a bioprosthesis is the:

The material used for the leaflets of a modern bileaflet mechanical heart valve is:

Structural failure of a glutaraldehyde-fixed bioprosthetic valve occurs principally through:

Synthetic vascular grafts of less than 6 mm diameter fail mainly because of:

Which material is used for a self-expanding carotid or peripheral artery stent?

The drug carried by a drug-eluting coronary stent acts to:

In the pacemaker code VVI, the third letter indicates that the pacemaker is:

A DDD pacemaker is chosen in preference to a VVI pacemaker mainly because it:

Pacemaker leads are frequently steroid-eluting at the electrode tip in order to:

An inferior vena cava filter is indicated principally when a patient with venous thromboembolism:

The intra-aortic balloon pump inflates:

Helium is used to drive the intra-aortic balloon because it:

In a patient with a modern continuous-flow left ventricular assist device, the commonest site of infection is the:

The bearing surface material in the great majority of total hip and knee replacements is:

PMMA bone cement fixes an implant to bone principally by:

For bone ingrowth into a cementless porous-coated implant to occur rather than fibrous tissue formation, micromotion must be kept below about:

Large-head metal-on-metal hip bearings were largely withdrawn because of:

Increasing the diameter of the femoral head in a hip replacement with a polyethylene liner:

The principal cause of late aseptic loosening of a hip replacement is:

A ceramic-on-ceramic hip bearing offers the advantage of:

Compared with the hip, the knee is mechanically more demanding to replace because its motion involves:

In a posterior-stabilised total knee replacement, the function of the posterior cruciate ligament is replaced by:

Increasing the conformity of a knee articulation lowers contact stress but has the drawback of:

Malalignment of the mechanical axis by a few degrees after total knee replacement is important because it causes:

Gentamicin is sometimes added to PMMA bone cement in order to:

Titanium alloy is preferred for a cementless femoral stem rather than cobalt-chromium mainly because of its:

The preferred material for a long-term indwelling urinary catheter is:

The balloon of a Foley catheter should be inflated with:

A catheter of size 18 French has an external diameter of:

The single most effective measure to reduce catheter-associated urinary tract infection is:

The curled ends of a double-J ureteral stent serve to:

Encrustation of urinary catheters and stents is caused principally by:

The mineral that forms the bulk of catheter encrustation and infection stones is:

A ureteral stent left in place and forgotten for a year is likely to:

Vesico-ureteric reflux may occur in a patient with a double-J stent because the stent:

Silver alloy coating of a urinary catheter is intended to:

A Coude tip catheter is used particularly when:

Polypropylene mid-urethral slings and pelvic meshes have become the subject of regulatory restriction mainly because of:

An artificial urinary sphincter consists of:

The commonest complication of breast implant surgery is:

A breast implant capsule that is firm, visibly distorted and painful is classified as Baker grade:

Cohesive silicone gel is preferred to older liquid gel because it:

BIA-ALCL, a rare lymphoma arising in the implant capsule, has been associated particularly with:

The great practical advantage of hyaluronic acid over permanent dermal fillers is that it:

The most serious complication of facial dermal filler injection is:

A bluish discoloration of the skin after hyaluronic acid filler placed too superficially is called:

Integra, the classic dermal regeneration template, consists of:

The principal limitation of cultured epidermal autograft in a massive burn is that it:

The gold standard for permanent coverage of a full-thickness burn remains:

Resorbable plates and screws are preferred to titanium for craniofacial fixation in young children because they:

A patient-specific cranioplasty implant is most commonly produced by:

In midface and mandibular fracture reconstruction, the reference used to guide reduction is the:

The commonest late complication after implantation of an intraocular lens is:

A square posterior optic edge on a modern intraocular lens serves to:

Which intraocular lens material should be avoided in an eye that may later require silicone oil tamponade?

The power of an intraocular lens is calculated principally from measurements of:

The original intraocular lens material, suggested by the observation that Perspex fragments were well tolerated in pilots' eyes, was:

Intrastromal corneal ring segments are implanted principally to treat:

The principal engineering difficulty with a keratoprosthesis is:

An Ahmed glaucoma valve differs from a Baerveldt implant in that it:

The commonest cause of late failure of a glaucoma drainage device is:

A porous hydroxyapatite orbital implant is preferred to a smooth PMMA sphere because it:

A retinal prosthesis can restore some visual perception only when:

Current retinal prostheses provide vision that is best described as:

An ophthalmic viscosurgical device such as a hyaluronic acid preparation is used during cataract surgery to:

The three essential components of the tissue engineering triad are:

Induced pluripotent stem cells are attractive for tissue engineering because they:

An ideal tissue engineering scaffold should have a porosity of:

For bone tissue engineering, the pore size generally regarded as optimal for cell ingrowth and vascularisation is about:

The degradation rate of a scaffold should ideally be:

Which fabrication technique produces fibres of a diameter comparable to natural extracellular matrix fibrils?

In the basic procedure of tissue engineering, cells are released from a tissue biopsy by:

Dynamic seeding under perfusion is preferred to static seeding because it gives:

The principal function of a perfusion bioreactor in tissue engineering is to:

The single greatest obstacle to engineering thick tissues and solid organs is:

Which tissue has been most successfully engineered and brought into clinical use?

A decellularised donor organ is attractive as a scaffold because it retains:

Mechanical loading is applied to a tissue-engineered tendon or cartilage construct in a bioreactor because: