gms | German Medical Science

Objectives: Knee stiffness requiring manipulation under anesthesia (MUA) is an undesirable outcome following total knee arthroplasty (TKA), however it is unknown whether performing an early or late MUA after calipered kinematically aligned (KA) TKA provides a better clinical outcome at a mean follow-up of five-years.

Methods: A review of the operating room records identified all primary TKAs (N=3558) that were treated with calipered KA by a single surgeon between 2010 and 2017 that subsequently underwent an MUA. An observer, independent of the treating physician, compared pre-TKA, pre-MUA, and final follow-up clinical characteristics and outcome scores between patients who underwent early ( ≤ 3 months from index surgery) and late (>3 months) MUA.

Results: Eighty-two patients were treated with an MUA for an incidence of 2%. Excluded were 11 patients not followed due to outdated contact information (6 early/5 late) and nine that declined to participate (2 early/7 late). At a mean follow-up after early vs. late MUA of 6.2 vs. 5 years, early treatment resulted in a better median Forgotten Joint Score (88 vs. 70 points) and Oxford Knee Score (46 vs. 42 points) (P =0.02 vs. 0.03, respectively) in spite of less pre-operative flexion in the early group (79 vs. 95 degrees) (P = 0.03) (Table 1 [Tab. 1]).

Conclusions: Surgeons should consider performing an MUA for stiffness within 3 months after calipered KA TKA as this results in higher patient-reported outcome scores than a later MUA. However, when stiffness is detected after 3 months, consider a late MUA as outcome scores improved and were compatible with useful function, even though the MUA was performed at a mean interval of eight months after the primary TKA.