What are the differences in the recovery of physical function and clinical score between patients with steroid-related osteonecrosis of the femoral head and hip osteoarthritis undergoing total hip arthroplasty? A propensity score-matched study.

PURPOSE: Steroid-related osteonecrosis of the femoral head (ONFH), arising from steroid administration for underlying diseases, represents a unique pathology for total hip arthroplasty (THA) and typically affects a younger demographic compared to osteoarthritis (OA). Given the significant age-related differences, this study aims to employ propensity score matching to align patient backgrounds between these two diseases and compare physical function. Additionally, our objective is to scrutinize the patterns of clinical score recovery over the course of one year following THA. METHODS: Using propensity score matching, 29 patients each with steroid-related ONFH and OA were selected. Muscle strength (hip abductor and knee extensor) were assessed before and after THA. Additionally, recovery of the Harris Hip Score (HHS) and Oxford Hip Score (OHS) up to one year postoperatively was analyzed. RESULTS: The steroid-related ONFH group exhibited gender bias and significantly younger age compared to the OA group. Propensity score matching achieved balanced patient backgrounds. Physical function showed trends of lower hip abduction and knee extensor strength on the operative side in the steroid-related ONFH group. Notably, nonoperative knee extensor strength decreased significantly after matching. HHS and OHS were poor in steroid-related ONFH up to three months postoperatively but recovered after six months. CONCLUSIONS: Patients with steroid-related ONFH experience positive outcomes in clinical score following THA. Propensity score matching effectively identified muscle weakness on both operative and nonoperative sides, highlighting its utility in comparative analyses.

Association of physical activity with fatty infiltration of muscles after total hip arthroplasty.

OBJECTIVE: This study aimed to investigate the association between muscle density as an indicator of fatty infiltration of lower extremity muscles and physical activity (PA) after total hip arthroplasty (THA) and identify the patient characteristics with high postoperative PA. METHODS: This study included 62 female patients who underwent THA for unilateral hip osteoarthritis. Muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles was measured using computed tomography (CT). PA was assessed using University of California, Los Angeles (UCLA) activity scores. CT and UCLA activity score were obtained before and 1 year after THA. The patients were divided into two groups, sufficient (score ≥ 6) and insufficient (score < 6) activity groups, based on their level of PA as determined by their UCLA activity score 1 year after THA. The association of PA with the amount of changes in muscle density was examined with Spearman's rank correlation coefficient. Logistic regression analysis was performed to identify postoperative factors determining PA at 1 year after THA. RESULTS: Spearman's rank correlation coefficient showed a significantly positive association between recovery in PA and an increase in muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles. Additionally, logistic regression analysis confirmed that postoperative muscle densities of the gluteus maximus and quadriceps muscles were variables determining the PA 1 year after THA. CONCLUSION: The findings of this study indicated that the improvement of fatty infiltration in lower limb muscles, especially in the gluteus maximus and quadriceps, is likely to promote the increase in postoperative PA.

Evaluating the contribution of fat infiltration in anterior gluteus minimus muscle to walking ability in female with unilateral hip osteoarthritis and candidates for total hip arthroplasty.

BACKGROUND: The purpose of this study is to investigate the relationship between gait and fat infiltration in anterior and posterior gluteus minimus in the patients with hip osteoarthritis. METHODS: Ninety-one female patients who were diagnosed as the unilateral hip osteoarthritis, classified into Kellgren-Lawrence global scoring system grades 3 or 4, and candidate for total hip arthroplasty were retrospectively reviewed. The horizontally cross-sectional regions of interest for the gluteus medius and anterior and posterior gluteus minimus were manually circumscribed in a single transaxial computed tomography image and muscle density of those regions were obtained. The gait was assessed as the step and speed with the 10-Meter Walk Test. The multiple regression analysis was used to compare the step and speed with age, height, range of motion in flexion, the muscle density of anterior gluteus minimus in the affected side, and that of gluteus medius muscle in both affected and unaffected sides. FINDINGS: Multiple regression analysis for step revealed that the muscle density of anterior gluteus minimus in the affected side and height were the independent predictors for step (R2 = 0.389, p < 0.001). That for speed identified the muscle density of anterior gluteus minimus in the affected side as the only factor determining speed (R2 = 0.287, p < 0.001). INTERPRETATION: The fatty infiltration of anterior gluteus minimus muscle in affected side can be a predictor for the gait in in female with unilateral hip osteoarthritis and candidates for total hip arthroplasty.

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.

Effect of gait distance during robot training on walking independence after acute brain injury.

This study aimed to determine whether the distance of gait training using a hybrid assistive limb (HAL) is related to the improvement of walking independence in patients with acute brain injury. This was an exploratory, observational study. Thirty patients having hemiplegia (functional ambulation category, FAC score ≤2) with acute stroke or after brain tumor surgery were included. Patients performed 4 sessions of gait training using HAL (60 min/session), 1-3 sessions/week, combined with conventional physical therapy. The gait distance achieved in the four training sessions using HAL was measured. FAC score was measured before and after intervention. Patients were divided into groups A, B, and C, for FAC score improvements of 0, 1, and ≥2, respectively. Gait distance was compared among groups using one-way analysis of variance. Gait distance in group C was significantly longer than that ingroup A [mean (standard deviation): 2527 (1725) m vs. 608 (542) m]. This study suggested that the gait distance achieved during training using the HAL may be a clinical indicator of the effectiveness of the HAL on gait training in patients with acute brain injury.Clinical trial registration number: UMIN000012764 R000014756.

Development of a Clinical Prediction Rule to Identify Physical Activity After Total Hip Arthroplasty.

OBJECTIVE: To develop clinical prediction rule (CPR) of physical activity 1 year after total hip arthroplasty (THA). DESIGN: Retrospective cohort study. SETTING: University hospital with orthopedic surgery. PARTICIPANTS: The study group included 321 patients (56 men) who underwent primary THA (N=321). INTERVENTION: Not applicable. MAIN OUTCOMES MEASURES: The data collected included age, body mass index, clinical score from the questionnaires, hip pain, range of motion, muscle strength, and Physical functions (10-meter walk test [10MWT], timed Up and Go test, sit-to-stand test). Patients were classified into sufficient and insufficient activity groups based on their University of California, Los Angeles (UCLA) activity score 1 year after THA. Variables measured preoperatively and 3 weeks postoperatively were analyzed using univariate and multivariate methods to derive CPR for physical activity. RESULTS: A CPR was developed using the following 5 factors and cutoffs: age 70.5 years or younger, preoperative UCLA activity score ≥3.5, preoperative hip abduction strength ≥0.54 Nm/kg, preoperative knee extension strength ≥1.04 Nm/kg, and 10MWT ≤8.49 seconds 3 weeks after surgery. The presence of 4 of the 5 factors predicted a sufficient physical activity level at 1 year, with a positive likelihood ratio of 5.94 and probability of 85.4%. The presence of 5 predictor variables increased the probability of sufficient physical activity after THA to 94.7%. CONCLUSIONS: This study developed a CPR for physical activity 1 year after THA. Having 4 or more of the 5 measurements were useful indicators for predicting of physical activity 1 year postoperatively.

Recovery of Muscle Atrophy and Fatty Infiltration in Patients With Acetabular Dysplasia After Total Hip Arthroplasty.

INTRODUCTION: Hip osteoarthritis (OA) with acetabular dysplasia negatively affects pelvic alignment and muscle function. We aimed to investigate the changes in muscle atrophy and fatty infiltration of the hip and trunk muscles 1 year after total hip arthroplasty (THA) in patients with hip OA with acetabular dysplasia. METHODS: This study included 51 female patients who underwent THA for unilateral hip OA with acetabular dysplasia. The cross-sectional area (CSA) and muscle density of the gluteus maximus, gluteus medius, gluteus minimus, piriformis, iliopsoas, rectus abdominis, and abdominal oblique muscles using computer tomography and pelvic inclination angle using radiographs were assessed before and 1 year after THA. RESULTS: At the 1-year follow-up, the CSA and muscle density of the gluteus medius (2,078 to 2,522 mm2 and 30.3 to 39.4 hounsfield units [HU]), iliopsoas (715 to 901 mm2 and 40.3 to 50.8 HU), and rectus abdominis (336 to 363 mm2 and 28.6 to 30.6 HU) of the affected limb had increased significantly (P < 0.05). The CSA and muscle density of the gluteus maximus (2,429 versus 2,884 mm2 and 23.7 versus 32.6 HU), gluteus minimus (636 versus 785 mm2 and 14.3 versus 37.1 HU), piriformis (505 versus 607 mm2 and 23.4 versus 31.6 HU), and iliopsoas (901 versus 997 mm2 and 50.8 versus 54.5 HU) in the affected limb were lower than those in the unaffected limb (P < 0.01). Postoperatively, the CSA and muscle density of the rectus abdominis were not significantly different between the limbs, and the pelvic inclination angle (35.2° to 32.1°, P < 0.01) was significantly decreased. DISCUSSION: Compared with the nonoperated limb, substantial atrophy and fatty infiltration of most hip muscles persisted in the operated limb 1 year after THA in patients with acetabular dysplasia; asymmetry in the rectus abdominis muscle fully resolved. In patients with acetabular dysplasia, the surgical technique and postoperative rehabilitation should be further considered to optimize hip muscle recovery.

Functional characteristics of female patients based on ambulatory ability 1 year after total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is commonly performed to reduce knee pain and improve physical function. Compared with the values for healthy, age-matched women, previous studies have reported large deficits in functional ability, such as muscle strength and ambulatory ability, in women 1 year post-TKA. Ambulatory ability is to move around, particularly by walking and is clinically assessed by the timed up and go test (TUG). AIM: This study aimed to clarify the characteristics of knee functions in female patients whose ambulatory ability recovered to a normal level at 1 year after TKA. METHODS: This cross-sectional study included 151 female patients who underwent TKA. The muscle strength of the lower extremity was measured, and the 2011 Knee Society Scoring (2011 KSS) system was used postoperatively. The TUG was conducted to assess ambulatory ability after TKA; then the patients were classified into the fast and slow ambulation groups based on previously reported gait-speed values of healthy female individuals. Then, we identified significant indicators of ambulatory ability at 1 year after TKA. RESULTS: Forty-nine percent of patients after TKA achieved the level of ambulatory ability of a healthy female. Logistic regression analysis identified that the non-operative side knee extensor strength and the functional activity score, as assessed by the 2011 KSS, were variables significantly associated with the mid-term ambulatory ability after TKA. CONCLUSION: Female patients with high non-operative knee extensor strength and a functional activity score at 1 year postoperatively can achieve better ambulatory ability than those of healthy, age-matched females.

Immediate family support is important to discharge home for cancer patient with bone metastasis after rehabilitation: A retrospective study.

ABSTRACT: The purpose of this study is to investigate the predictive factors of home discharge for rehabilitation patients with cancer bone metastasis.Cancer patients with bone metastasis who underwent rehabilitation between April 2014 and March 2017 were retrospectively enrolled. Data on discharge destination were collected from medical records as outcomes. Multiple regression analyses were carried out to investigate the predictive factors of home discharge.Ninety-eight patients (mean age: 68.6 years, 42 females and 56 males) were included. Fifty patients were discharged home, 38 patients were discharged to other facilities, and 10 patients died. There were no skeletal-related events among these patients during their hospital stay. The receiver-operating curve for the predictive factors for home discharge of the Barthel Index at admission, Eastern Cooperative Oncology Group Performance Status at admission, and number of immediate family members living at home were 60 points (area under the curve [AUC] = 0.74, sensitivity = 0.6400, 1-specificity = 0.2766), 2 score (AUC = 0.65, sensitivity = 0.5400, 1-specificity = 0.2222), and 1 family member (AUC = 0.65, sensitivity = 0.9592, 1-specificity = 0.7222), respectively.In order to plan for cancer patients with bone metastasis to be discharged home, it is important to take into consideration the patients' Barthel Index and Performance Status at the time of hospital admission and the number of immediate family members living at home.

Functional characteristics associated with hip abductor torque in severe hip osteoarthritis.

BACKGROUND: Hip abductor weakness due to the progression of hip osteoarthritis (OA) commonly causes poor functional mobility. The hip abductor strength has also been identified as a clinically relevant factor for successful functional outcomes after total hip arthroplasty. OBJECTIVES: This study aimed to examine the functional characteristics related to hip abductor torque in patients with hip OA. DESIGN: A cross-sectional survey study. METHODS: One hundred and eight female patients with severe unilateral hip OA participated in this study. Hip abductor torque and pain were measured. The muscle cross-sectional area (CSA) and skeletal muscle density (SMD) of the gluteal muscles were also measured using computed tomography. To identify the hip parameters associated with hip abductor torque, multiple regression analysis was performed. The healthy model included the CSA and SMD of gluteus maximus, gluteus medius, and gluteus minimus; range of motion in hip abduction; age; and body mass index. The affected model included hip pain in addition to the healthy model. RESULTS: In the affected limb, multiple regression analysis identified pain and angle of hip abduction as factors that determine hip abductor torque (Adjusted R2 = 0.39). In contrast, our analysis identified CSA and SMD of the gluteus medius and SMD of the gluteus minimus as the significant variables related to hip abductor torque in the healthy limb (Adjusted R2 = 0.40). CONCLUSION: The findings of this study indicated that it is necessary to consider that hip pain may inhibit muscle exertion and contraction while training to improve the hip abductor torque in the affected limb.

Hip Abductor Strength and Lower Limb Load on Nonoperating Predict Functional Mobility in Women Patients With Total Hip Arthroplasty.

OBJECTIVE: The aim of this study was to identify which aspect of the preoperative lower limb functions is most likely to affect the functional mobility at 6 mos after total hip arthroplasty. DESIGN: The study subjects included 125 women who underwent total hip arthroplasty. Hip flexion and abduction angles, hip abductor and knee extensor strengths, and lower limb load were measured preoperatively. The Timed Up and Go test was performed 6 mos postoperatively. Then, patients were divided into fast or slow groups as per the comparison with the Timed Up and Go score of healthy women. RESULTS: Hip abductor strength and lower limb load on the nonoperative side were revealed as significant measurements that affected functional mobility after total hip arthroplasty according to stepwise multiple logistic regression analysis. Moreover, receiver operating characteristic curve analyses showed that the postoperative functional mobility was predicted by the lower limb load of the nonoperative side (cutoff point, 8.97 N/kg; sensitivity, 62.3%; specificity, 82.8%; and area under the curve, 77.5%). CONCLUSIONS: This study revealed that patients with preoperative hip abductor strength of greater than 0.66 Nm/kg and lower limb load of greater than 8.97 N/kg on the nonoperative side could achieve better functional mobility at 6 mos postoperatively than healthy women of the same age group.