Abstract
Eliminating pain and restoring physical activity are the main goals of total hip arthroplasty (THA). Despite the high relevance of activity as a rehabilitation goal of and criterion for discharge, in-hospital activity between operation and discharge has hardly been investigated in orthopaedic patients.
Therefore, the aim of this study was to a) measure for reference the level of in-hospital physical activity in patient undergoing a current rapid discharge protocol, b) compare these values to a conventional discharge protocol and c) test correlations with pre-operative activities and self-reported outcomes for possible predictors for rapid recovery and discharge.
Patients (n=19, M:F: 5:14, age 65 ±5.7 years) with osteoarthritis treated with an elective primary THA underwent a rapid recovery protocol with discharge on day 3 after surgery (day 0). Physical activity was measured using a 3D accelerometer (64×25×13mm, 18g) worn on laterally on the unaffected upper leg. The signal was analysed using self-developed, validated algorithms (Matlab) calculating: Time on Feet (ToF), steps, sit-stand-transfers (SST), mean cadence (steps/min), walking bouts, longest walk (steps).
For the in-hospital period (am: ca. 8–13h; pm: ca. 13–20h) activity was calculated for day 1 (D1) and 2 (D2). Pre-operative activity at home was reported as the daily averages of a 4-day period. Patient self-report included the HOOS, SQUASH (activity) and Forgotten Joint Score (FJS) questionnaires.
In-hospital activity of this protocol was compared to previously collected data of an older (2011), standard conventional discharge protocol (day 4/5, n=40, age 71 ±7 years, M:F 16:24).
All activity parameters increased continuously between in-hospital days and subsequent am and pm periods. E.g. Time-on-feet increased most steeply and tripled from 21.6 ±14.4min at D1am to 62.6 ±33.4min at D2pm. Mean Steps increased almost as steep from 252 to 655 respectively. SST doubled from 4.9 to 10.5. All these values were sign. higher (+63 to 649%) than the conventional protocol data.
Cadence as a qualitative measure only increased slowly (+22%) (34.8 to 42.3steps/min) equalling conventional protocol values. The longest walking bout did not increase during the in-hospital period. Gender, age and BMI had no influence on in-hospital activity.
High pre-op activity (ToF, steps) was a predictor for high in-hospital activity for steps and SST's at D2pm (R=0.508 to R=0.723). Pre-op self-report was no predictor for any activity parameter.
In-hospital recovery of activity is steep following a cascade of easy (ToF) to demanding (SST) tasks to quality (cadence). High standard deviations show that recovering activity is highly individual possibly demanding personalised support or goals (feedback).
Quantitative parameters were all higher in the rapid versus the conventional discharge protocol indicating that fast activation is possible and safe. Equal cadence for both protocols shows that functional capacity cannot be easily accelerated.
Pre-op activity is only a weak predictor of in-hospital recovery, indicating that surgical trauma affects patients similarly, but subjects may be identified for personalized physiotherapy or faster discharge.
Reference values and correlations from this study can be used to optimize or shorten in-hospital rehabilitation via personalization, pre-hab, fast-track surgery or biofeedback.
