One of orthopedic medicine's most entrenched post-surgical assumptions—that structured physical rehabilitation is essential after hip or knee replacement—now faces a second direct challenge from a rigorous randomized trial. For the millions of adults who undergo joint arthroplasty each year, this finding carries real implications for how recovery protocols, healthcare costs, and patient expectations are structured.
The DRAW2 trial enrolled 169 patients following total hip or knee arthroplasty and randomly assigned them to six weeks of home-based telerehabilitation, conventional home-based rehabilitation, or no physical rehabilitation at all. The primary outcome—a validated disability and functional score (HOOS/KOOS ADL subscale)—showed mean differences between rehabilitation and no-rehabilitation groups of just -0.5 points at six weeks and 0.8 points at three months, with confidence intervals straddling zero and p-values of 0.70 and 0.52, respectively. Neither rehabilitation modality demonstrated superiority, and these results directly replicate the earlier DRAW1 trial.
The significance here lies not just in the finding, but in the deliberate replication design—a rarity in surgical rehabilitation research. Single null trials are often dismissed as underpowered anomalies; a pre-registered replication with the same protocol substantially raises the evidentiary weight. That said, important caveats apply. The sample size of 169, while adequate for detecting clinically meaningful differences, may miss smaller but real effects in specific subpopulations—particularly patients with greater baseline disability, advanced age, or comorbidities. The six-week intervention window also may not capture longer-term divergence in outcomes, and adherence in the no-rehabilitation arm was not pharmacologically controlled. Furthermore, these were patients recruited into a trial, likely representing more motivated, less complex cases than the broader surgical population. Whether findings extend to high-risk or lower-baseline-function patients remains unanswered. Still, for routine, uncomplicated arthroplasty, this evidence suggests natural recovery may be sufficient—a potentially paradigm-shifting result for standard care pathways.
