Cemented Versus Hybrid Technique of Fixation of the Stemmed Revision Total Knee Arthroplasty: A Literature Review

A Literature Review

Charles Ayekoloye, MD, FRCS; Mehran Radi, MD; David Backstein, MD, MED, FRCSC; Moayad Abu Qa'oud, MD

Disclosures

J Am Acad Orthop Surg. 2022;30(9):e703-e713. 

In This Article

Radiographic Analysis: The Implication of Radiolucent/Radiodense Lines

Radiographic assessment of TKA is undertaken using the original Knee Society Total Knee Arthroplasty Radiographic Evaluation and Scoring system designed by Ewald[31] or its modification.[32] It assesses implant position, knee alignment, and fixation interface integrity. Tibial fixation integrity is evaluated on AP (7 zones) and lateral views (3 zones), while femoral fixation interface is assessed on the lateral view (7 zones) with patella assessed on skyline views (3 to 5 zones). Scores are determined by measuring the width of radiolucent line in each zone in millimeters, the sum of which provides an indication of the integrity of the bone–cement/cement–implant interface. A score of 4 or less and nonprogressive is probably not significant (Figure 3). A score of 5 to 9 should be closely followed up, particularly if progressive and 2 mm or more in thickness. Finally, a score of 10 or more signifies possible or impending loosening with implant migration denoting a definitely loose implant (Figure 4). Studies have shown that complete radiolucent lines do not necessarily imply loosening.[33] A histologic analysis of bone–cement interface demonstrated that even with partial or complete radiolucent lines seen on radiographs, cement–bone contact can be observed, thus indicating fixation stability.[34] Other factors such as a history of symptoms, presence of features suggestive of a biomechanically unsound reconstruction, time of onset, and progression and widening of radiolucent lines are important considerations in determining whether a complete radiolucent line portends loosening.[35]

Figure 3.

Radiograph showing nonprogressive radiolucent lines.

Figure 4.

Radiograph showing loose implants with tibial stems failure. Tibia loose stems in a hybrid fixation stem (A), and in a fully cemented stem (B).

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