Survivorship of TKA in post-ACL reconstruction knees lower than expected

Following anterior cruciate ligament (ACL) injury, 20% of patients will develop osteoarthritis. Despite this, there remains a paucity of data describing outcomes of total knee arthroplasty (TKA) after prior ACL reconstruction.

J.M. Wilson et al aimed to describe survivorships, complications, radiographic results, and clinical outcomes of TKA after ACL reconstruction in one of the largest series to date. The study was conducted at Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota. It has been published in “The Journal of Arthroplasty.”

The authors identified 160 patients (165 knees) who underwent primary TKA following prior ACL reconstruction using the total joint registry. The mean age at TKA was 56 years (range, 29-81), 42% were women, and their mean body mass index was 32. Ninety percent of knees were posterior-stabilized designs. Survivorship was assessed using the Kaplan-Meier method. The mean follow-up was 8 years.

Key findings of the study were:

• The 10-year survivorships free of any revision and any reoperation were 92 and 88%, respectively.

• Seven patients were revised for instability (6 global and 1 flexion), 4 for infection, and 2 for other reasons.

• There were 5 additional reoperations: 3 manipulations under anesthesia, 1 wound debridement, and 1 arthroscopic synovectomy for patellar clunk.

• Non operative complications occurred in 16 patients, 4 of which were flexion instability.

• Radiographically, all non revised knees were well-fixed.

• Knee Society Function Scores significantly improved from preoperative to 5 years postoperative (P < .0001).

The authors concluded that – “Survivorship of TKA in post-ACL reconstruction knees was lower than expected with instability being the most common reason for revision. In addition, the most common non revision complications were flexion instability and stiffness requiring manipulations under anesthesia, indicating that achieving soft tissue balance in these knees may be difficult.”

Further reading:

Total Knee Arthroplasty in Patients Who had a Prior Anterior Cruciate Ligament Reconstruction: Balancing Remains the Issue, Jacob M. Wilson, James R. Markos et al, The Journal of Arthroplasty, https://doi.org/10.1016/j.arth.2023.02.037