Total Knee Arthroplasty (TKA) MCQs

During a total knee arthroplasty (TKA) gap balancing procedure, the surgeon notes that the knee is well-balanced and symmetric in extension, but symmetrically tight in 90 degrees of flexion. Which of the following is the most appropriate step to achieve balanced gaps?

A 65-year-old woman with advanced primary knee osteoarthritis undergoes a posterior-stabilized (PS) TKA. The surgeon inadvertently internally rotates the tibial component. What is the most likely biomechanical consequence of this malrotation?

A patient with a severe 25-degree valgus knee deformity and a completely incompetent medial collateral ligament (MCL) presents for TKA. Which of the following implant constraints is most appropriate?

During a TKA, a measured resection technique is utilized. The surgeon uses the surgical transepicondylar axis (sTEA) to establish femoral component rotation. Which of the following best describes the sTEA?

A 55-year-old male presents with a symptomatic extra-articular distal femoral varus deformity of 15 degrees located 5 cm proximal to the joint line. If the surgeon decides to correct this entirely with an intra-articular bone cut during a TKA, what is the most significant risk?

In a posterior-stabilized (PS) TKA, at approximately what angle of flexion does the cam on the femoral component typically engage the tibial post to initiate posterior femoral rollback?

A patient presents with 'patellar clunk syndrome' two years following a TKA. Which implant characteristic and kinematic phase are most classically associated with this condition?

Increasing the posterior slope of the tibial bone cut during a TKA will have which of the following effects on the flexion and extension gaps?

In an excessively thick (overstuffed) patellar component during TKA, which of the following postoperative complications is most directly expected?

Intraoperatively during a TKA, a surgeon finds the knee is tight in full extension but perfectly balanced in 90 degrees of flexion. Which of the following is the most appropriate next step to balance the knee?

A patient with severe osteoarthritis and an 18-degree varus deformity is evaluated for TKA. Preoperative imaging reveals a Joint Line Convergence Angle (JLCA) of 6 degrees (opening laterally). How does this affect preoperative bone resection planning?

A patient has significant anterior bowing of the femoral diaphysis. If a standard intramedullary alignment guide is utilized during primary TKA, what is the most likely error in the distal femoral resection?

During revision TKA, the joint line is inadvertently elevated by 10 mm. Which of the following biomechanical consequences is most likely to occur?

A 58-year-old patient with severe knee osteoarthritis has an extra-articular varus deformity of the proximal tibial diaphysis due to a malunited fracture. What is the generally accepted threshold of extra-articular coronal plane tibial deformity beyond which a simultaneous or staged corrective osteotomy is recommended over intra-articular compensatory resection during TKA?

A patient with significant distal femoral diaphyseal anterior bowing (procurvatum deformity) undergoes standard primary TKA using a traditional long intramedullary femoral alignment guide. If uncorrected, this diaphyseal deformity will most likely cause the femoral component to be placed in:

During a primary PCL-substituting (PS) TKA, the trial reduction demonstrates a perfectly balanced extension gap, but the flexion gap is excessively tight, limiting flexion to 85 degrees. Which of the following is the most appropriate next step to balance the knee?

According to current orthopedic consensus, what is the generally accepted threshold of extra-articular coronal plane tibial deformity beyond which a simultaneous or staged extra-articular osteotomy is typically recommended during TKA?

Which of the following technical errors during the placement of TKA components is most likely to increase the Q-angle and precipitate lateral patellar maltracking?

A 70-year-old female undergoes TKA for a fixed 15-degree valgus deformity. During trial reduction, the knee is perfectly balanced in 90 degrees of flexion, but the lateral compartment remains asymmetrically tight in full extension. Which structure should be selectively released next?

When setting the rotational alignment of the tibial component during primary TKA, aligning the center of the tibial tray to the medial third of the tibial tubercle serves to optimize patellofemoral mechanics primarily by: