3. Adult Reconstruction (Hip & Knee) MCQs

A patient with a modular uncemented total hip arthroplasty presents with unexplained hip pain and rising serum cobalt levels. Radiographs show no loosening. Fretting and mechanically assisted crevice corrosion are most likely occurring at which of the following interfaces?

Ceramic-on-ceramic bearings in total hip arthroplasty provide the lowest volumetric wear rates of all modern bearing surfaces. However, their use is specifically associated with which of the following unique complications?

Ceramic-on-ceramic bearings in total hip arthroplasty are chosen for their excellent wear properties. However, a specific complication unique to ceramic bearings is:

A 50-year-old active man receives a ceramic-on-ceramic total hip arthroplasty. Which of the following is a recognized complication specific to this bearing surface compared to metal-on-polyethylene?

A patient with a cementless total hip arthroplasty shows significant proximal femoral bone loss at 5-year follow-up. The femoral stem is fully porous-coated and well-fixed distally. This phenomenon is a clinical manifestation of:

A total hip arthroplasty is performed using a heavily porous-coated, stiff cobalt-chromium femoral stem. Over several years, proximal femoral bone resorption is noted on radiographs. This phenomenon is primarily caused by:

In total hip arthroplasty, microscopic asperities on the hard femoral head can scratch and systematically remove material from the softer polyethylene liner. This mechanism of material loss is classified as:

Highly cross-linked polyethylene (HXLPE) is extensively used in total hip arthroplasty due to its enhanced wear properties. However, increased cross-linking involves which of the following biomechanical tradeoffs?

In total hip arthroplasty, the use of highly cross-linked polyethylene has significantly reduced the incidence of osteolysis. This improvement is primarily due to a reduction in which type of wear?

Which particle size of polyethylene wear debris is most highly associated with macrophage activation and subsequent periprosthetic osteolysis?

Which specific mode of wear is characterized by the generation of particulate debris when micro-asperities between two articulating bearing surfaces bond together and are subsequently torn away from the softer material?

Which of the following is considered the primary wear mechanism occurring in a well-functioning metal-on-polyethylene total joint arthroplasty?

A surgeon is performing a posterior (Moore) approach to the hip. The short external rotators are detached near their trochanteric insertions and reflected posteriorly. Which muscle is intentionally left intact to protect the medial circumflex femoral artery (MFCA) from iatrogenic injury?

During an anterior approach to the ankle for arthrodesis, the surgeon develops the interval between the extensor hallucis longus (EHL) and the extensor digitorum longus (EDL). Which neurovascular bundle lies deep within this interval and must be mobilized and protected?

During a direct lateral (Hardinge) approach to the hip for arthroplasty, the gluteus medius is split longitudinally. To avoid denervating the anterior portion of the gluteus medius and tensor fasciae latae, the split should not extend proximally beyond the tip of the greater trochanter by more than what distance?

A surgeon is performing a direct lateral (Hardinge) approach to the hip for arthroplasty. To prevent denervation of the anterior portion of the gluteus medius, the proximal split of the muscle should not extend beyond what maximum distance from the tip of the greater trochanter?

During a posterior approach to the hip (Kocher-Langenbeck), the surgeon tags and releases the short external rotators. To preserve the primary blood supply to the adult femoral head, the surgeon must protect the ascending branch of the medial femoral circumflex artery. Where does this crucial vessel typically run?