Functional recovery and timing of hospital discharge after primary total hip arthroplasty.

Abstract

Early discharge programmes in hospitals are encouraged to increase financial efficiency and bed availability, but standards of clinical care must not be compromised. Criteria for safe hospital discharge must be established and objective data are needed to assess how rapidly patients can achieve these discharge criteria. A prospective study was performed on 65 patients (mean age = 71 years) scheduled for primary total hip arthroplasty (THA). The Modified Barthel Index (MBI) was measured pre-operatively and postoperatively at set intervals to asses recovery of function after THA. A score of 90 out of a possible 100 was used as a discharge criterion and indicated that the patient was functionally independent for safe hospital discharge. In addition, a combined score for thigh flexion and extension isokinetic peak strength was recorded for each patient before and after surgery. The number and nature of comorbidities and complications were also recorded. The length of hospital stay in this sample varied from 5 to 39 days. The MBI scores increased rapidly between days 3 and 5, then began to plateau from day 8 onwards. Based on the MBI, 58% of patients were fit for discharge at or before day 8. The remainder were fit for discharge from day 10 onwards (mean = 14.2 days). The latter group who required an extended hospital stay were older (P = 0.003), had more identified comorbidities (P = 0.01) and were weaker in their hip musculature prior to surgery (P = 0.001), compared to those who were discharged by day 8. A logistic regression analysis indicated that the pre-operative MBI score and hip strength score were strong predictors of timing for hospital discharge. A clinical pathway with functional milestones laid out over 8 days would be an appropriate criterion for the discharge of the majority of patients. However, approximately 40% of the patients presented in this study required a longer hospital stay before the criteria for safe discharge could be achieved. These patients can be identified pre-operatively by screening their MBI and composite hip strength scores.