Postoperative cognitive dysfunction is rare after fast-track hip- and knee arthroplasty - But potentially related to opioid use.

STUDY OBJECTIVE: Postoperative cognitive dysfunction (POCD) remains a frequent postoperative complication in non-fast-track surgeries, with negative implications for return to daily activities and work. In fast-track total hip and -knee arthroplasty (THA/TKA) an 8-9% incidence of POCD after 3 months has been reported, but without details on specific perioperative risk factors. Thus, we re-investigated the incidence and role of suggested factors for POCD in a well-controlled patient cohort, to guide future preventive interventions. DESIGN: A subanalysis of a prospective study. SETTING: Hospital ward, patients own home. PATIENTS: One-hundred-and-four patients undergoing elective THA/TKA. INTERVENTIONS: A full contextual and validated cognitive test battery pre- and 2-3 weeks postoperatively by interview by research nurse. MEASUREMENTS: Results from the cognitive test battery were corrected for learning effect by normative data from an age-matched unoperated control group. Potential perioperative risk factors (age, procedure, gender, inflammation, blood-percentage, opioids etc.) associated with POCD was investigated by univariate and multivariate logistic analysis, with a 5% significance level. MAIN RESULTS: Four patients (3.9%) developed POCD. POCD-positive patients consumed higher dose of opioids in the acute postoperative period (postoperative days 0-3: median 214 mg), vs. POCD-negative patients (postoperative days 0-3: median 98 mg, p = 0.008), and during the 2-3-week study period (POCD-positive vs. POCD-negative patients, median 739 mg vs. 208 mg, respectively). Other pre and postoperative factors were non-significant but associated with the development of POCD. CONCLUSION: POCD is rare in fast-track THA/TKA patients and may be related to postoperative opioid consumption, supporting the ongoing focus on opioid-sparing analgesia.

Objectively measured early physical activity after total hip or knee arthroplasty.

Although reduced early physical function after total hip- and knee arthroplasty (THA/TKA) is well-described, the underlying reasons have not been clarified with detailed studies on pathophysiological mechanisms related to recovery, thereby prohibiting advances in rehabilitation. Thus, we aimed to describe early post-THA/TKA physical activity measured by actigraphy and potential underlying pathophysiological mechanisms related to recovery in a well-defined cohort of THA and TKA patients. Daytime-activity was measured from 2 days before until 13 (THA) or 20 (TKA) days after surgery. The primary outcome was individualized recovery in activity, with secondary analyses of activity-intensities and association to the perioperative factors: sex, age, BMI, hemoglobin (hgb), C-reactive protein and postoperative pain. Eighty-one THA/TKA-patients were examined. A large inter-individual variation in early physical activity was found. On a group level, activity was significantly reduced compared to preoperatively the first 2 (THA) or 3 (TKA) weeks after surgery (mean-difference - 64 counts × 103/day, p < 0.001 and - 78 counts × 103/day, p < 0.001, respectively). All activity-intensities were affected with the largest decline in high intense activity. A slight overall improvement in activity was seen during the postoperative phase [THA: 1%/day (SD 2.15); TKA: 0.7%/day (SD 1.04)], but approximately 30% of THA and 20% of TKA patients had reduced and declining activity. Hgb, CRP, BMI (THA) and postoperative pain (TKA) were only weakly associated with impaired physical activity. Physical activity was reduced the first weeks following THA/TKA, but with large inter-individual variations in recovery profiles. No single pathogenic factor was associated with a poor recovery. Early risk stratified interventions are needed in patients on a suboptimal course.