Low Grip Strength Associated with Clinical Outcomes After Total Hip Arthroplasty - A Prospective Case-Control Study

Objective: To assess whether low grip strength (GS) is associated with clinical outcomes after total hip arthroplasty (THA).

Methods: A prospective case-control study was designed to assess 231 cases of primary THA between January 1, 2015 to May 1, 2018, at an urban tertiary care hospital. Patients were placed into two cohorts based on preoperative GS levels. Low GS in the present study was defined as GS lower than 26 kg for men and 16 kg for women in the dominant hand. Baseline data were prospectively collected and included patient demographics (age, sex, body mass index [BMI]), the surgeon's diagnoses, medical history, length of stay, and American Society of Anaesthesiologists' (ASA) score. Clinical outcomes included surgery- and prosthesis-related variables. The Harris hip score (HHS) and the Short Form Health Survey (SF-12) were completed at the baseline visit and at 1 and 2 years postoperatively in the outpatient department to assess the hip's function and quality of life. Differences in baseline data, length of study (LOS), 90-day postoperative complications, and hospital readmissions were compared. Besides, the correlations between GS and Harris hip score (HHS) and Short Form score (SF-12) were tested.

Results: A total of 202 participants have completed records for analysis finally. The patients were followed up for an average of 24.8 months postoperatively (24-26 months). Eighty-two patients (40.6%) had low GS before THA. Patients with low GS were more likely to be female, older, fracture of femoral head or neck as the primary cause, albumin <3.5 g/dL, and have a lower BMI, higher ASA score, increased rates of the pressure sore, blood transfusion, and LOS compared to normal GS (all P < 0.05). Also, patients in the low GS cohort showed a statistically significant increased unplanned hospital readmissions and decreased discharge home compared to normal GS (both P < 0.05). There was an increasing rate of complications between the two cohorts, for cardiac complications, pressure sore after THA, respiratory complications, urinary tract infection, stroke, and DVT (all P < 0.05). A partial correlation test by controlling medical comorbidities and demographic factors was used to determine the correlation between GS and HHS. There was a significant correlation between them (r = -0.673; P = 0.002). A similar condition was detected in the correlation between GS and SF-12 (r = 0.645; P = 0.001).

Conclusions: Clinicians should be encouraged to include GS assessment in their evaluation of patients who planned to undergo THA in order to optimize the treatment of high-risk individuals.