Total knee arthroplasty in patient with poliomyelitis sequelae: maintaining a recurvatum is associated with better mid-term functional results.

PURPOSE

Total knee arthroplasty (TKA) in patients with sequelae of poliomyelitis is a surgical challenge due to muscle weakness, bone deformities or post-polio syndrome (PPS). Few data exist to determine the factors contributing to poor functional results. This study aimed: (1) to describe a cohort of patients with poliomyelitis sequelae who underwent TKA; (2) to examine risk factors for poor functional outcome.

METHODS

A monocentric retrospective cohort study of all patients with poliomyelitis sequelae who underwent TKA between January 2006 and December 2019. Clinical, functional outcomes, radiographic results and occurrence of complications were collected.

RESULTS

A total of 22 patients (24 knees) were included in the analysis, with a mean follow-up of 6.6 years (from 2 to 13.7 years). There was an improvement in KSS (28 +/- 23 vs. 81 +/- 6, respectively; p < 0.0001) as well as functional KSS (25 +/- 12 vs. 57.5 +/- 21, respectively; p = 0.0001). There was less occurrence of annual knee giving way episodes after total knee replacement (11.9+/-16.1 vs. 5.1+/-13.7, respectively; p = 0.04). Even though the total knee replacement allowed a slight recurvatum, it was smaller than the preoperative recurvatum (13° vs. 8°, respectively; p = 0.04). Seven complications with reintervention (7/24; 29%) were found. The presence of a residual post operative recurvatum correlated with better KSS (ρ = 0.53, CI95% [0.15; 0.77]; p = 0.008). The number of postoperative annual knee giving way episodes was inversely correlated with persistent postoperative recurvatum (ρ = -0.42, CI95% [-0.69; -0.01]; p = 0.04) but was not correlated with the type of constraint (ρ = -0.26, CI95% [-0.6; 0.15]; p = 0.21) nor with quadricipital muscle strength (ρ = 0.21, CI95% [-0.21; 0.56]; p = 0.33).

CONCLUSION

TKA has a good mid-term functional outcome for knee osteoarthritis in patients with sequelae of poliomyelitis. Preserving a residual recurvatum postoperatively gives better clinical results without increasing the risk of ligament instability or early aseptic loosening.

LEVEL OF EVIDENCE

IV.