Relationship between vertical ground reaction force and muscle strength while climbing stairs after total hip arthroplasty

Association between Quadriceps Muscle Strength and the Forgotten Joint Score after Total Hip Arthroplasty

BACKGROUND

Total hip arthroplasty (THA) effectively enhances hip function and alleviates pain in patients who have osteoarthritis, improving their quality of life. The Forgotten Joint Score-12 (FJS-12), a patient-reported outcome measure, has recently gained attention as a method for assessing joint awareness during daily activities following THA; however, the association between muscle strength, specifically quadriceps muscle strength, and the FJS-12 has not been fully investigated.

METHODS

This cross-sectional study involved 624 patients who underwent THA at a single center in Japan. The mean patient age was 67 years (range, 43 to 94), and 85.3% of the cohort were women. We aimed to investigate the association between quadriceps muscle strength and the FJS-12 (measured at 12 months postoperatively) using multiple regression analyses adjusted for variables such as pain and leg length discrepancy.

RESULTS

The mean FJS-12 was 72.2, and the mean quadriceps muscle strength was 1.2 Nm/kg. Higher quadriceps muscle strength was significantly associated with better FJS-12 outcomes (β = 0.28, P < 0.001). Conversely, increased pain and perceived leg length discrepancy were negatively associated with lower FJS-12 values.

CONCLUSIONS

Our findings indicate that quadriceps muscle strength is a crucial determinant of joint awareness as measured using the FJS-12 in patients undergoing THA. These results highlight the potential benefits of targeted rehabilitation to enhance quadriceps muscle strength, which may help patients undergoing THA experience less joint awareness in their daily activities.

Influence of tactile and verbal guidance on lateral weight-shifting in double-leg standing after total hip arthroplasty

INTRODUCTION

Anomalous gait after total hip arthroplasty (THA), marked by increased trunk lateral flexion during weight-bearing, is a noteworthy aspect to consider for enhancing ambulatory capacity. One potential training modality that is feasible in the early post-THA period is lateral weight shifting during double-leg standing. However, the influence of physical therapists' instructional guidance on trunk lateral flexion and hip abductor muscle activity in this context remains unclear.

PURPOSE

To investigate the influence of physical therapist's guidance directed towards reducing the trunk lateral flexion angle during lateral weight-shifting in double-leg standing post-THA.

METHODS

Twenty THA patients, assessed at 2 weeks postoperatively, performed lateral weight-shifting under two conditions: the normal condition and the instructed condition, for comparison. The latter involved tactile and verbal guidance guidance to minimize trunk lateral flexion. Patients were categorized based on trunk flexion direction for comparison, exploring the correlations between hip abductor muscle activity and kinematic parameters.

RESULTS

In the instructed condition, a significant reduction in trunk lateral flexion and increased hip lever arm length were observed compared to those in the normal condition. Patients with trunk flexion towards the operated side exhibited a notable reduction, while those on the non-operated side showed no significant changes. Gluteus medius muscle activity correlated with trunk lateral flexion, and tensor fasciae latae muscle activity correlated with body's center of mass lateral displacement and hip adduction angle.

CONCLUSIONS

Physical therapist's guidance influenced lateral weight-shifting in double-leg standing post-THA. Differences in the trunk lateral flexion direction may lead to different effects from the guidance.

Reproducibility, criterion-related validity, and minimal clinically important difference of the stair negotiation test after total Hip arthroplasty

OBJECTIVE

To determine the reproducibility, criterion-related validity, and minimal clinically important difference (MCID) of the stair negotiation test (SNT) after total hip arthroplasty (THA).

METHODS

Sixty patients who underwent THA were included in this study. They performed the SNT and rated their difficulty in stair negotiation (question 7 of the Oxford Hip Score [OHSQ7]) before and 6 months after surgery. The SNT determined the time taken by a patient to ascend, turn around, and descend the stairs (15 cm × 4 steps) and was measured twice each time. As a measure of reproducibility, the intraclass correlation coefficient (ICC1,1) was calculated using the preoperative SNT. As an index of criterion-related validity, Spearman's rank correlation coefficient was used to evaluate the relationship between the better score of two trials in the preoperative SNT and the OHSQ7. The MCID of the SNT was calculated using the distribution-based method and the anchor-based method. The change in the OHSQ7 between before and after surgery was used as an anchor in the latter method.

RESULTS

The ICC1,1 of the SNT was 0.97. The SNT was significantly correlated with the OHSQ7 (r = 0.40, p < .05). Moreover, the anchor-based MCID of the SNT was 1.98 seconds.

CONCLUSION

The SNT is an objective assessable test of stair negotiation ability in post-THA patients that has good reproducibility and moderate criterion-related validity. Changes in the SNT beyond the MCID (1.98 seconds) represent clinically important changes in stair negotiation ability.

Early biomechanical outcome in patients with acetabular fractures treated using the pararectus approach: a gait and stair climb analysis study

Purpose

Patients with surgically treated acetabular fractures using extensive dissection of hip muscles demonstrate an incomplete biomechanical recovery and limited joint mobility during movement. The purpose of this study was to evaluate the early biomechanical outcome in a series of patients with acetabular fractures treated using the less invasive anatomical pararectus approach.

Methods

Eight patients (48 ± 14 years, BMI 25.8 ± 3 kg/m²) were investigated 3.8 ± 1.3 months after surgery and compared to matched controls (49 ± 13 years, BMI 26 ± 2.8 kg/m²). Trunk and lower extremity kinematics and kinetics during gait and stair climb were calculated. SF-12 and the Merle d’Aubigné score were used for functional evaluation. Statistical analysis was conducted using Mann–Whitney test and Student’s t test. Effect sizes were calculated using Cohen’s d.

Results

No group differences for lower extremity kinematics during walking and stair climbing were found. During walking, patients showed significant reductions (p < 0.05) of the vertical ground reaction force (8%) and knee and hip extension moments (29 and 27%). Ipsilateral trunk lean was significantly increased by 3.1° during stair descend while reductions of vertical ground reaction force were found for stair ascend (7%) and descend (20%). Hip extension moment was significantly reduced during stair descend by 37%. Patients revealed acceptable SF-12 physical and mental component outcomes and a good rating for the Merle d’Aubigné score (15.9 ± 1.7).

Conclusion

Patients showed some biomechanical restrictions that can be related to residual deficits in weight bearing capacity and strength of the hip muscles. In contrast, an immediate recovery of mobility was achieved by preserving lower extremity and pelvic movement. Therefore, the pararectus approach can serve as a viable strategy in the surgical treatment of acetabular fractures.

Clinical trial

Trial registration number DRKS00011308, 11/14/2016, prospectively registered.