PREOPERATIVE FUNCTIONAL MOBILITY AS AN INDEPENDENT DETERMINANT OF INPATIENT FUNCTIONAL RECOVERY AFTER TOTAL KNEE REPLACEMENT DURING CLINICAL PATHWAY CHANGES

van der Sluis G.^1,2, Goldbohm A.³, Elings J.^1,4, Bimmel R.⁵, Akkermans R.⁶, Nijhuis-van der Sanden M.W.G.⁷, Hoogeboom T.⁶, Van Meeteren N.¹

¹Maastricht University, Caphri, Maastricht, Netherlands, ²Nij Smellinghe Hospital, Physical Therapy, Drachten, Netherlands, ³TNO, Healthy for Life, Leiden, Netherlands, ⁴Diakonessenhuis, Physical Therapy, Utrecht, Netherlands, ⁵Nij Smellinghe hospital, Orthopaedics, Drachten, Netherlands, ⁶Radboud University Medical Center, IQ Healthcare, Nijmegen, Netherlands, ⁷Radboud University Medical Center, IQ healthcare, Nijmegen, Netherlands

Background: Fast postoperative mobilization and recovery of functional mobility is essential to prevent adverse effects, in particular in high risk (frail) patients.
Preoperative functional mobility might be one of the few determinants of postoperative recovery that is modifiable through physical therapy interventions.

Purpose: Investigate whether preoperative functional mobility is a determinant of delayed inpatient recovery of activities (IRoA) after total knee replacement (TKR) in three time periods that coincided with clinical pathway changes.

Methods: All patients (n=682) scheduled for TKR between 2009 and 2015, were preoperatively screened for functional mobility by the Timed-up-and-Go test (TUG) and De Morton mobility index (DEMMI). The cut-off point for delayed IRoA was set on the day that 70% of the patients were recovered, according to the Modified Iowa Levels of Assistance Scale (mILAS) (a 5-item activity scale). In a multivariable logistic regression analysis, we added either the TUG or the DEMMI to a reference model including established determinants. To investigate whether time period modified the relationship between functional mobility and inpatient recovery of activities, we added the periods (two indicator variables) and their interaction with preoperative TUG or DEMMI data, respectively, as terms to the model.

Results: Both the TUG (OR 1.10 per second, 95% CI: 1.06-1.15) and the DEMMI (OR 0.96 per point on the 100-point scale, 95% CI: 0.95-0.98) were statistically significant determinants of delayed IRoA in a model that also included age, BMI, ASA score and ISAR score. These associations did not depend on the time period during which the TKR took place, as assessed by tests for interaction.

Conclusion(s): Functional mobility, as assessed preoperatively by the TUG and DEMMI, is an independent and stable determinant of delayed IRoA after TKR.

Implications: Poor preoperative functional mobility hampers inpatient recovery of activities in people undergoing total knee replacement. Improvement of preoperative functional mobility through tailored physiotherapy intervention may enhance postoperative recovery.

Funding acknowledgements: No benefits in any form have been received from a commercial party related directly or indirectly to the study.

Topic: Orthopaedics

Ethics approval: The ethical committee of the Nij Smellinghe hospital gave approval regarding this study.

All authors, affiliations and abstracts have been published as submitted.