Validity of an oblique posterior condylar radiographic view for revision total knee arthroplasty

Evaluating the progression of osteolysis after total knee arthroplasty

Osteolysis around the knee following total knee arthroplasty continues to be a leading cause for revision total knee arthroplasty. Risk factors for periprosthetic knee osteolysis are associated with excessive polyethylene wear and include, but may not be limited to, malalignment of the mechanical axis, early-generation polyethylene sterilization techniques, excessive backside polyethylene wear, metal-backed patellar components, patient age, and an elevated body mass index. The initial diagnosis of osteolysis is frequently discovered on routine surveillance radiographs. The location, size, progressive nature, and associated symptomatology of the defect guides treatment. Surgical indications and timing are predicated on the risk of failure with continued observation. Advanced imaging helps to quantitate the size and location of osteolytic lesions as accurately as possible and aids in preoperative planning. When deciding whether surgery or management with continued radiographic surveillance is indicated, a global assessment of the character and progression of the osteolysis must be weighed with the risk factors associated with the patient.

The painful knee after TKA: a diagnostic algorithm for failure analysis

Pain after total knee arthroplasty (TKA) represents a common observation in about 20% of the patients after surgery. Some of these painful knees require early revision surgery within 5 years. Obvious causes of failure might be identified with clinical examinations and standard radiographs only, whereas the unexplained painful TKA still remains a challenge for the surgeon. It is generally accepted that a clear understanding of the failure mechanism in each case is required prior considering revision surgery. A practical 10-step diagnostic algorithm is described for failure analysis in more detail. The evaluation of a painful TKA includes an extended history, analysis of the type of pain, psychological exploration, thorough clinical examination including spine, hip and ankle, laboratory tests, joint aspiration and test infiltration, radiographic analysis and special imaging techniques. It is also important to enquire about the length and type of conservative therapy. Using this diagnostic algorithm, a sufficient failure analysis is possible in almost all patients with painful TKA.

The management of bone loss in revision total knee replacement

The management of bone loss in revision replacement of the knee remains a challenge despite an array of options available to the surgeon. Bone loss may occur as a result of the original disease, the design of the prosthesis, the mechanism of failure or technical error at initial surgery. The aim of revision surgery is to relieve pain and improve function while addressing the mechanism of failure in order to reconstruct a stable platform with transfer of load to the host bone. Methods of reconstruction include the use of cement, modular metal augmentation of prostheses, custom-made, tumour-type or hinged implants and bone grafting. The published results of the surgical techniques are summarised and a guide for the management of bone defects in revision surgery of the knee is presented.

Hybrid total knee arthroplasty: 13-year survivorship of AGC total knee systems with average 7 years followup

A retrospective study of 201 anatomic graduated component total knee arthroplasties implanted with hybrid fixation at the authors' center was performed in response to conflicting data in the literature concerning the benefits of a hybrid method. Selection for hybrid fixation was nonrandomized and based on femoral component fit. Survivorship analysis was performed, and rates of radiolucent lines surrounding the femoral component and occurrence of osteolysis were noted. At 7 and 13 years, survivorship with tibial or femoral revision as the end point was 0.9926 and 0.9732, respectively. Radiolucencies were found adjacent to 15 femoral components at final followup (seven in Zone 1, three in Zone 2, five in Zone 3, one in Zone 4, two in Zone 5, zero in Zone 6). Osteolysis was observed in one knee after secondary evaluation. Hybrid fixation in a selected patient population can result in excellent results in middle to long-term followup.