Muscle strength and functional recovery during the first year after THA

Identifying Deficits in Hip and Knee Muscle Strength on the Surgical and Nonsurgical Sides in Women up to 12 Months After Total Hip Arthroplasty

OBJECTIVE

Regaining hip and knee muscle strength is important after total hip arthroplasty (THA). However, it is unclear if muscles other than those of the operated hip also lose strength. This study aimed to identify deficits in hip and knee strength on the surgical and nonsurgical sides in female patients up to 12 months after THA.

METHODS

Participants were 91 female patients who had hip osteoarthritis and underwent unilateral THA. Forty-six community-dwelling women who were asymptomatic were selected as control participants. Patients with locomotor disorders or postsurgical complications were excluded. Maximal isometric strength of the hip flexors, extensors, and abductors and knee extensors and flexors on the surgical and nonsurgical sides were measured before THA and 3, 6, and 12 months thereafter.

RESULTS

Twelve months after THA, hip flexion, extension, and abduction strength on the surgical side were 84.6%, 83.5%, and 76.2%, respectively, of those in individuals who were asymptomatic; at the same time point, those on the nonsurgical side were 94.8%, 83.9%, and 79.4%, respectively. Knee extension strength on the surgical side was 89.3% of that in individuals who were asymptomatic. Compared to individuals who were asymptomatic, nearly all muscles showed significantly lower strength on both sides up to 6 months after THA.

CONCLUSION

At 12 months after THA, hip and knee strength on both the surgical and nonsurgical sides did not recover to the level observed in individuals who were asymptomatic. In particular, hip abductor strength on the surgical and nonsurgical sides were 76% and 79%, respectively, of that in individuals who were asymptomatic.

IMPACT

At 12 months after THA, hip and knee strength on the surgical and nonsurgical sides did not recover to the level observed in individuals who were asymptomatic, suggesting that the nonsurgical side may be inappropriate as a control to assess strength recovery on the surgical side.

Effects of lower limb vibration on hip pain and function after total hip arthroplasty: A randomized controlled trial

BACKGROUND

A vibration roller is an effective tool for reducing muscle soreness and improving damaged muscle function. However, its efficacy in reducing hip pain and improving function after total hip arthroplasty is unclear. We investigated the effect of lower limb vibration using a vibration roller on postoperative hip pain and function after total hip arthroplasty in a randomized controlled clinical trial.

METHODS

Thirty patients scheduled for total hip arthroplasty were randomly assigned to vibration and control groups. The patients in the vibration group performed lower limb vibration using a vibration roller. The patients in the control group performed sham therapy using a hot pack. Patients performed both interventions for 10 min daily on postoperative days 1-7, in addition to regular physical therapy. Primary outcome was hip pain intensity as measured using a visual analog scale. Secondary outcomes were pain-pressure threshold and serum creatine kinase and C-reactive protein levels. We also assessed physical functions, including the Harris Hip Score, range of motion of the hip joint, muscle strength, gait velocity, and timed up-and-go test. The effects of the interventions on outcome measurements in the groups were compared using a split-plot design variance analysis.

RESULTS

After one week of the intervention and three weeks of follow-up, the vibration group showed statistically significant improvement in the exercise-induced hip pain, pain-pressure threshold of lateral thigh, and serum creatine kinase compared to the control group (p = 0.006, 0.003, and 0.012, respectively). No statistically significant differences were found between the groups regarding the physical functions.

CONCLUSIONS

Lower limb vibration using a vibration roller after total hip arthroplasty was an effective intervention to reduce exercise-induced hip pain and improve serum creatine kinase, but there was no synergistic effect on the physical functions.

Recovery of Muscular Strength Following Total Hip Replacement: A Narrative Review

This narrative review analyzes muscle strength recovery following total hip replacement (THR) and looks at various factors affecting postoperative muscle function restoration. The review synthesizes evidence from various studies regarding the timing and degree of muscular strength recovery, different rehabilitation protocols, and patient-specific variables such as age, preoperative physical condition, and comorbidities, among others. Overall, it appears that THR is associated with improved hip function and quality of life, but this usually takes a long time due to individualized physical therapy interventions. In addition, postoperative rehabilitation has been found not to exist without any personal factors involved such as age or gender whereby for instance senior citizens have no alternative but to go for THR surgery, making their lower limbs weaker than those who are younger. Based on the findings in this review on muscle recovery after THR surgeries, one may conclude that this endeavor should begin as early as possible and include regular resistance training programs with performance-focused functional training after surgery. In addition, more longitudinal studies should be conducted regarding post-surgical outcomes comparing other traditional medical practices.

Comparison of outcomes after total hip arthroplasty between patients with osteonecrosis of the femoral head in Association Research Circulation Osseous stage III and stage IV: a five-year follow-up study

BACKGROUND

No large cohort study has evaluated the surgical outcomes of THA between different stages of ONFH patients. This study aimed to compare the surgical outcomes of ONFH patients who underwent THA in ARCO stage III versus IV, in terms of operative parameters, one-year hip function assessments and postoperative at least five-year complications, to inform optimized management of ONFH.

METHOD

From our prospectively collected database, 876 patients undergoing THA between October 2014 and April 2017 were analyzed and divided into ARCO stage III group (n = 383) and ARCO stage IV group(n = 493). Details of demographics, medical record information, adverse events and clinical scores of both groups were collected and compared. Proper univariate analysis was used for the analysis.

RESULT

There were no statistically significant differences in baseline characteristics between the two groups. Compared to ARCO stage IV patients, ARCO stage III patients showed a shorter operative time (p < 0.01), less bleeding (p < 0.01), fewer one-year readmissions (p = 0.026) and complications (p = 0.040), and significantly higher HHS (p < 0.01) one year after THA. In addition, ARCO stage IV patients seem more likely to suffer prosthesis dislocation (p = 0.031).

CONCLUSION

Although ARCO stage IV patients in the study cohorts appeared to suffer more one-year complications, no significant difference was observed at long-term follow-up. Enhanced clinical guidance on preventing early prosthesis dislocation may help improve the prognosis of final-stage ONFH patients.

Incorporating Functional Strength Integration Techniques During Total Hip Arthroplasty Rehabilitation: A Randomized Controlled Trial

OBJECTIVE

Total hip arthroplasty (THA) is a common orthopedic procedure that alleviates pain for millions of individuals. Yet, persistent physical function deficits, perhaps associated with movement compensations, are observed after THA. These deficits negatively affect quality of life and health for many individuals. Functional strength integration (FSI) techniques combine muscle strength training with specific movement retraining to improve physical function. This study aimed to determine if FSI would improve functional performance through remediation of movement compensations for individuals after THA.

METHODS

A double-blind randomized controlled trial was conducted. Ninety-five participants were randomized to either the FSI or control (CON) group for an 8-week intervention. The FSI protocol included exercise to improve muscular control and stability around the hip to minimize movement compensation during daily activity. The CON protocol included low-load resistance exercise, range-of-motion activities, and patient education. Functional performance, muscle strength, and self-reported outcomes were measured preoperatively, midway and after intervention, and 6 months after THA. Change from preoperative assessment to each time point was measured, and between-group differences were assessed.

RESULTS

There were minimal differences in outcomes between groups at the first postoperative assessment. There were no statistically significant between-group differences in the later assessments, including the primary endpoint. Both groups improved functional outcomes throughout the study period.

CONCLUSION

The FSI intervention did not result in greater improvements in function after THA compared to the CON intervention. Future work should further investigate additional biomechanical outcomes, timing of the FSI protocol, effective dosing, and patient characteristics predictive of success with FSI.

IMPACT

Recovery after THA is complex, and individuals after THA are affected by persistent movement deficits that affect morbidity and quality of life. The present study suggests that either approach to THA rehabilitation could improve outcomes for patients, and that structured rehabilitation programs may benefit individuals after THA.

Minimal Influence on Muscle Strength and Patient Reported Outcome Measures by Conjoined Tendon Detachment in Anterolateral Muscle-Sparing Total Hip Arthroplasty

Purpose

The conjoined external rotator tendon (CERT), composed of the tendons of the gemellus superior, obturator internus (OI), and gemellus inferior muscles, stabilizes the hip joint. The study investigates the clinical and radiological effects of the CERT release during anterolateral-supine approach (ALSA) total hip arthroplasty (THA).

Methods

A cohort of 60 patients who underwent ALSA THA was examined. Pre- and post-operative muscle width, muscle strength, and radiological data were compared between the CERT-detached and preserved groups. In addition, Clinical assessments were performed using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire and the short-form 36 questionnaires.

Results

58.3% had CERT detached, resulting in radiological atrophy of the OI muscle. Despite this, hip flexion, extension, and abduction muscle strength significantly improved at 6 months post-surgery. The detached CERT did not substantially affect patient-reported outcome measures, including pain and daily activities, within the 6-month follow-up.

Discussion

The study suggests that while CERT detachment can lead to muscle atrophy, it has a limited impact on muscle strength and patient-reported outcome measures, indicating the muscle's potential redundancy. Preserving the CERT might enhance stability and prevent atrophy but could increase the risk of complications. CERT release is recommended when femur exposure is inadequate.

The effects of modified hardinge approach on hip muscle strength in patients with primary hip arthroplasty: a patient evaluation with isokinetic strength test and gait analyses

OBJECTIVE

Numerous factors affect abductor strength after Total hip arthroplasty (THA), including surgical technique, prosthesis type, postoperative rehabilitation program, and preoperative patient condition. We prospectively investigated the effects of the modified Hardinge approach on hip muscle strength, which was evaluated using the isokinetic test, functional results, and gait function of patients who underwent primary THA.

METHODS

The hip muscles strength were measured using an isokinetic dynamometer. The primary outcomes of the present study were measurement of isokinetic strength of hip abductor muscle strengths using an isokinetic evaluator and gait analyses preoperatively and at 6 months postoperatively in 27 patients.

RESULTS

Isokinetic muscle strength test, abductor and other hip circumference groups achieved the preoperative muscle strength at 3 months postoperatively, and the postoperative sixth month values showed a statistically significant improvement compared with the preoperative and third month values. In gait analyze, our temporospatial data showed a slight regression at postoperative 3 months but reached the same values at 6 months postoperatively. Kinematic data showed a significant regression, but the data were not compared with those in the preoperative period.

CONCLUSIONS

Adequate muscle strength and physiological gait pattern, similar to the preoperative status, can be achieved at 6 months postoperatively.

LEVEL OF EVIDENCE

Level III.

Preoperative Body Composition Correlates with Postoperative Muscle Volume and Degeneration after Total Hip Arthroplasty

Impaired muscle recovery after total hip arthroplasty (THA) may affect gait and activities of daily living. Bioelectrical impedance analysis (BIA) can assess body composition and muscle volume, and computed tomography (CT) can assess muscle volume and the fatty degeneration of muscle. This study aimed to explore the effectiveness of BIA, and the correlation between preoperative body composition and postoperative muscle volume and degeneration after THA using BIA and CT. Thirty-eight patients who underwent THA and had BIA and CT performed pre- and postoperatively were retrospectively assessed. The BIA-derived measurements of preoperative body composition (fat mass index, fat-free mass index, and phase angle) were correlated with the CT-derived measurements (pre- and postoperative muscle volume and gluteus maximus and quadriceps Hounsfield Units of the affected hip). The preoperative fat mass index negatively correlated with the postoperative muscle volume of the gluteus maximus (p = 0.02) and quadriceps (p < 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.03). The preoperative fat-free mass index positively correlated with the postoperative muscle volume of the quadriceps (p = 0.02). The preoperative phase angle positively correlated with the postoperative muscle volume of the quadriceps (p = 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.001). In patients who underwent THA, preoperative body composition correlated with postoperative muscle volume and the fatty degeneration of the affected lower limb. Preoperative body composition may help predict postoperative muscle volume and fatty degeneration and thus, postoperative recovery.

Mechanical energy flow analysis in athletes with and without anterior cruciate ligament reconstruction during single-leg drop landing

Techniques that reduce mechanical energy have been linked to lower chances of experiencing an Anterior Cruciate Ligament (ACL) injury. Although there is evidence that movement patterns are altered in athletes who have undergone Anterior Cruciate Ligament Reconstruction (ACLR), energy transfer mechanisms have not been examined. This study aimed to compare energy flow mechanisms during single-leg drop landing between athletes with and without history of ACLR. A total of 20 female athletes were included in this study. Ten participants underwent ACLR 12 months ago (mean age, 21.57 ± 0.41 years) and 10 were healthy controls (mean age, 20.89 ± 0.21 years). Participants executed the single-leg drop landing (SLL) maneuver by descending from a 30 cm wooden box and landing on the tested leg on an embedded force plate. Information collected during the SLL trials was refined using rigid-body analysis and inverse dynamics within Nexus software, ultimately allowing construction of skeletal models of the athletes. Ankle and knee mechanical energy expenditure (MEE) was higher in the control participants during landing. However, the result for the hip MEE demonstrated that MEE of the control group was significantly lower compared with the ACLR group, but MEE of the control subjects was higher as compared to ACLR group (p ˂ 0.05). Results suggest the avoidant use of the quadriceps muscle post ACLR leads to knee-avoidant mechanics and loss of knee joint power generation during a SLL task.

Early Recovery of Physical Function After Total Hip Arthroplasty in a Patient With Osteopetrosis: A Case Report

Osteopetrosis is an uncommon and inherited disorder. Some disease-specific characteristics, such as diffuse osteosclerosis and a high incidence of fractures, may potentially affect postoperative rehabilitation. This report presents a case of successful rehabilitation early after total hip arthroplasty for osteopetrosis. A 56-year-old Japanese man, who was diagnosed with osteopetrosis at the age of 11, underwent total hip arthroplasty in the right hip. Full weight-bearing was allowed on the day after the operation; the postoperative rehabilitation program was proceeded based on a standard program as done after total hip arthroplasty for osteoarthritis. A shoe lift in the left leg was used in supervised walking training to correct the imbalanced alignment due to leg length discrepancy. The patient could walk independently with a cane 17 days after the operation. Three weeks after the operation, the patient demonstrated comfortable and maximal walking speed of 1.11 and 1.34 m/s, respectively, and maximal hip abductor muscle strength of 3.96 kgf･m, both of which were better than those before the operation. There were no adverse events during the postoperative rehabilitation course. These findings suggest the safety and efficacy of standard rehabilitation programs after total hip arthroplasty even in individuals with osteopetrosis. In addition, it may be important to consider the whole-body condition in the rehabilitation of individuals with osteopetrosis.

Functional Ability, Psychological Factors, and Rehabilitation Outcomes After Elective Total Hip Replacement

Background. The role of positive psychological factors in acute rehabilitation after total hip replacement (THR) is unclear. Purpose. (a) Examine the trajectory of functional ability among older adults after THR from presurgery to discharge from acute rehabilitation and (b) determine which physical and psychological factors at admission would predict functional ability at discharge and length of stay in rehabilitation. Methods. This prospective cohort study included 30 participants (age M = 76.20 years) from an inpatient geriatric rehabilitation center. They completed the Geriatric Depression Scale and Positive Affect questionnaire. The FIM® Motor domain of Functional Independent Measure (mFIM) was recorded presurgery, at admission, and upon discharge. Findings. Functional ability improved at discharge; however, the presurgery functional ability was not regained. Positive affect explained the length of stay in rehabilitation above and beyond the presurgery mFIM. Implications. Occupational therapists should improve ways to enhance self-care and positive affect in acute rehabilitation.

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.

Relationship Between Self-Reported Function, Functional Tests and Biomechanical Parameters in Patients 12 Months After Total Hip Arthroplasty: A Preliminary Cross-Sectional Study

Background/Purpose

Several methods are used to evaluate the outcome of total hip arthroplasty (THA), however, their relationship at different time points after surgery is unclear. The purpose of this exploratory study was to investigate correlations between self-report function, performance-based tests (PBTs) and biomechanical parameters in patients 12 months after THA.

Methods

Eleven patients were included in this preliminary cross-sectional study. Hip disability and Osteoarthritis Outcome Score (HOOS) was completed for self-reported function. As PBTs, the Timed-up-and-Go test (TUG) and 30-Second-Chair-Stand test (30CST) were used. Biomechanical parameters were derived from analyses of hip strength, gait and balance. Potential correlations were calculated using Spearman correlation coefficient r.

Results

HOOS scores and parameters of PBTs showed moderate to strong correlations (0.3 < r < 0.7). Correlation analysis between HOOS scores and biomechanical parameters revealed moderate to strong correlations for hip strength whereas correlations with gait parameters and balance were rather weak (r < 0.3). Moderate to strong correlations were also found between parameters of hip strength and 30CST.

Conclusion

For THA outcome assessment 12 months after surgery, our first results indicate that self-report measures or PBTs could be used. Analysis of hip strength also appears to be reflected in HOOS and PBT parameters and may be considered as an adjunct. Given the weak correlations with gait and balance parameters, we suggest that gait analysis and balance testing should be performed in addition to PROMs and PBTs as they may provide supplementary information, especially for THA patients that are at risk for falls.

Determination of Relationships between Symmetry-Based, Performance-Based, and Functional Outcome Measures in Patients Undergoing Total Hip Arthroplasty

Due to the high heterogeneity in outcome measures after total hip arthroplasty (THA), the prospective observational study investigated the relationships between symmetry-based (SBMs), performance-based (PBMs), and functional outcome measures in THA patients to determine necessary or redundant categories of tests. The study material consisted of 24 patients with end-stage hip osteoarthritis scheduled for THA. The patients were examined one day before surgery and consecutively on the 4th day, 9th day, and 10th week postoperatively using the SBMs (weight-bearing chair-rising test, measurements of the maximal isometric torque of the quadriceps muscle); the PBMs (10-m walk, timed up-and-go, and stair-climbing tests); and the functional outcome measure (Harris Hip Score). The results obtained in a given category of tests at different time points were compared, and the correlations between the tests were determined. The reliability of the outcome measures was determined. The results of tests in the studied categories statistically significantly (p < 0.05) improved at the 10th week postoperatively compared to preoperative results. No strong correlations were revealed between the three studied types of outcome measures in THA patients. Therefore, none of them can be considered redundant. It also means that the relevance of symmetry for a core measurement set to describe the domain function in THA patients must be further clarified.

Effects of cross-training on motor function and length of stay after total hip arthroplasty: A randomized controlled trial

BACKGROUND

There is no consensus about which training methods will give better early outcomes after total hip arthroplasty (THA).

OBJECTIVE

To investigate the short-term effects of cross trainer exercise on physical function and walking ability following THA.

METHODS

Fifty patients who underwent THA were randomly allocated into two groups. The intervention program was started 3 days after surgery. The main physical function results were pain, hip range of motion, knee extensor strength, single-leg stance time, and walking performance test. In addition, the number of days of requiring to walk and the length of hospital stay were recorded.

RESULTS

In the comparison between groups at discharge, the patients in the cross trainer group had significantly less hip pain while walking, improvement in knee extensor strength, increased single-leg stance time, as well as increased walking speed and stride length at discharge. The number of days required to walk and length of stay were also significantly lower in the intervention group.

CONCLUSIONS

Conclusions: Cross trainer exercise commencing 3 days postoperatively improves physical function and walking ability after THA.

Effects of the Practice of Movement Representation Techniques in People Undergoing Knee and Hip Arthroplasty: A Systematic Review

OBJECTIVE

To analyze the effects of movement representation techniques (MRT) combined with conventional physical therapy (CFT) in people undergoing knee and hip arthroplasty compared to conventional physical therapy alone in terms of results in physical and functionality variables, cognitive function, and quality of life.

METHODOLOGY

the review was carried out according to the criteria of the PRISMA statement, considering studies in the electronic databases PubMed/Medline, Pubmed Central/Medline, Web of Science, EBSCO, and ScienceDirect.

RESULTS

MRT plus CFT generated therapeutic effects in some aspects of the physical variables: 100% pain (7 of 7 studies); 100% strength (5 out of 5 studies); range of motion 87.5% (7 out of 8 studies); 100% speed (1 of 1 study), functional variables: 100% gait (7 of 7 studies); functional capacity 87.5% (7 out of 8 studies); cognitive variables: 100% motor visualization ability (2 out of 2 studies); cognitive performance 100% (2 of 2 studies); and quality of life 66.6% (2 of 3 studies). When comparing its effects with conventional physical therapy, the variables that reported the greatest statistically significant changes were motor visualization ability, speed, pain, strength and gait. The most used MRT was motor imagery (MI), and the average time extension of therapies was 3.5 weeks.

CONCLUSIONS

movement representation techniques combined with conventional physical therapy are an innocuous and low-cost therapeutic intervention with therapeutic effects in patients with knee arthroplasty (KA) and hip arthroplasty (HA), and this combination generates greater therapeutic effects in physical, functional, and cognitive variables than conventional physical therapy alone.

Implementation of falls risk evaluation at one-year after total hip arthroplasty: a cross-sectional study

Background

Research has demonstrated an increased risk of falls after total hip arthroplasty (THA). Yet, people’s knowledge on falls risk factors and how falls prevention strategies are being used after THA have not been examined. If a person’s knowledge of falls and self-efficacy about falls prevention strategies is low this would indicate a pressing need for interventions to lessen risk. The study objectives were: 1) to determine the falls knowledge and what fall prevention strategies people used after (THA) and 2) to determine the outcomes of a falls risk assessment at 12-months after unilateral THA.

Methods

Overall, 108 people completed the Falls Risk for Older People – Community Setting (FROP-Com) scale, a falls questionnaire (covered occurrence of falls, knowledge on falls risk factors, falls prevention strategies implemented after THA surgery), 6-m Walk Test (6mWT), 30-Second Chair Stand Test (30CST), Timed-up and Go (TUG) Test, and Activities-specific Balance Confidence Scale (ABC).

Results

Twenty-five (23.2%) people fell at least once in the 12 months after THA. Scores on the FROP-Com ranged from 2–20 with an average of 8.2 ± 3.6 indicating a mild falls risk. The importance of falling compared to other health concerns was rated as moderate to high (6.8 ± 2.9) and the majority of participants (n = 98, 90.7%) believed falls can be prevented after THA. Total scores on the ABC scale ranged from 30.6% to 100.0% with an average score of 84.4 ± 15.5%, indicating high function. Only 47 people (43.5%) reported receiving falls prevention education. A total of 101 falls prevention strategies were completed by 67 people (62%), the most common strategy was environmental modifications (e.g., installation of grab bars) at 37.4%, while exercise was mentioned by only 2%. The majority of people had functional deficits in 30CST (62%) and TUG (76.9%) at 12-months after unilateral THA.

Conclusions

Almost a quarter of the sample had experienced a fall in the 12-months after THA and functional deficits were common. The majority of the sample had proactively implemented falls prevention strategies after the surgery. Yet importantly, people after THA had limited exposure to falls prevention education and implemented a limited range of prevention strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40945-022-00141-6.

Association between Hip Center Position and Isokinetic Hip Muscle Performance after Anterolateral Muscle-Sparing Total Hip Arthroplasty

Background and objectives: The superior placement of the acetabular cup induced the delayed recovery of abductor muscle moment after total hip arthroplasty (THA) with a conventional posterior approach. The anterior-based muscle-sparing (ABMS) THA effectively reduces soft tissue damage, including muscles. The influence of hip center position on anterior-based muscle-sparing (ABMS) total hip arthroplasty (THA) for post-operative hip muscle strength was unclear. We evaluate whether the hip center position affects the recovery of hip muscle strength after ABMS THA. Materials and Methods: The study was performed as a retrospective cohort study, and included 38 hips in 38 patients that underwent primary ABMS THA. Muscle strength was measured using isokinetic dynamometry before the operation, and at 6 and 12 months after surgery. The horizontal and vertical centers of rotation (H-COR and V-COR), vertical shift (V-shift), leg length, and global femoral offset were determined radiographically in reference to a previous report. Results: A weak negative correlation was observed between abduction muscle strength at 6 months and V-shift; a V-shift more than 15 mm demonstrated significantly decreased abductor muscle strength at 6 months. Conclusions: The superior placement of the hip center caused delayed recovery of abductor muscle strength in hips with anterolateral minimally invasive THA. There seems to exist no biomechanical reason why the same should not also be the case for the muscle-sparing approach.

Development of a clinical prediction rule to identify physical activity after total hip arthroplasty

OBJECTIVE

To develop clinical prediction rule (CPR) of physical activity at 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.

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, Timed Up and Go test and Sit-to-stand). 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 at 3 weeks postoperatively were analyzed using univariate and multivariate methods to derive CPR for physical activity.

RESULTS

A CPR was developed using the following five factors and cut-offs: age, ≤70.5 years; preoperative UCLA activity score, ≥3.5; preoperative hip abduction strength, ≥0.54 Nm/kg; preoperative knee extension strength, ≥1.04 Nm/kg; and 10-Meter Walk Test, ≤8.49 s at 3 weeks after surgery. The presence of four of the five 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 five predictor variables increased the probability of sufficient physical activity after THA to 94.7%.

CONCLUSION

This study developed a CPR for physical activity at 1-year after THA. Having four or more of the five measurements were useful indicators for predicting of physical activity at 1 year postoperatively.

Efficacy of Belt Electrode Skeletal Muscle Electrical Stimulation in the Postoperative Rest Period in Patients with Diabetes who Have Undergone minor Amputations: A Randomized Controlled Trial

This study aimed to investigate whether belt electrode skeletal muscle electrical stimulation (B-SES) would improve postoperative lower limb function and walking ability in patients with diabetes who have undergone minor amputations. Diabetic patients who had undergone minor amputations were assigned randomly to a B-SES or control group. The B-SES group underwent conventional physical therapy for 20 min and B-SES for 20 min. The control group underwent only the 20-min conventional physical therapy. In both groups, rehabilitation was introduced by the physical therapists for 14 days from postoperative day 1. The outcome measures were range of motion in the ankle joint, knee extension muscle strength, ambulation status, and quality of life score. All these were evaluated before the intervention and 2 and 4 weeks after the intervention. From the 84 patients initially assessed, 32 were assigned to either the B-SES (N = 16) or control (N = 16) group. Preoperatively, there were no significant differences in all endpoints. The B-SES group showed significant improvement in the ankle dorsiflexion angle at 2 weeks postoperatively and knee joint extension strength at 4 weeks postoperatively. Postoperative B-SES with standard physical therapy might improve the range of motion of dorsiflexion of the ankle joint and extensor strength of the knee joint in patients with diabetes who have undergone minor amputations. B-SES is a useful tool to improve postoperative physical function in diabetic patients who have undergone minor amputations. A multicenter study is needed to determine the effective B-SES combined with regular physiotherapy for minor amputation.

Strong relationship of muscle force and fall efficacy, but not of gait kinematics, with number of falls in the year after Total Hip Arthroplasty for osteoarthritis: An exploratory study

BACKGROUND

In people with moderate hip osteoarthritis, gait kinematics was reported to be correlated with number of falls in the preceding year. After Total Hip Arthroplasty, subjects generally improve but still fall. The present study explores recovery and correlations with number of falls in the year after Total Hip Arthroplasty.

METHODS

We assessed 12 patients one year after Total Hip Arthroplasty, 12 patients with moderate hip osteoarthritis with at least one fall in the preceding year, and 12 healthy peers. Maximum hip abduction strength, Fall Efficacy Scale - International, Harris Hip Score, pain, and number of falls in the preceding year were assessed. Participants walked on a treadmill with increasing speeds, and gait kinematics were registered optoelectronically. We assessed group differences, and correlations of all variables with number of falls.

FINDINGS

After arthroplasty, subjects tended to score better on variables measured, often non-significantly, compared to subjects with moderate osteoarthritis, but worse than healthy peers. Maximum hip abduction strength together with fall efficacy had a strong regression on the number of falls in the preceding year (R² = 92%). Gait kinematics did not correlate with number of falls, and also fall efficacy was not related to gait kinematics.

INTERPRETATION

One year after hip arthroplasty, muscle strength sufficiently recovered for normal walking, but not to avoid falling in risky situations. Rehabilitation should focus on muscle strength. The lack of correlation between the Fall Efficacy International and gait kinematics, suggests that it reflected the experience of having fallen rather than fear.

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.

Incidences and circumstances of falls among women following total hip arthroplasty on long-term follow-up

BACKGROUND

Patients who undergo total hip arthroplasty have an increased risk of falls during the first postoperative year. However, it is unclear whether patients after total hip arthroplasty will continue to be at high risk of falls more than 1 year postoperatively. To better understand whether the risk of falls changes after a 1-year period, we investigated the incidences and circumstances of falls in women patients for 5 years after total hip arthroplasty.

METHODS

This longitudinal prospective cohort study analyzed 65 women with severe hip osteoarthritis who underwent total hip arthroplasty. The incidences and circumstances of falls before total hip arthroplasty and at 1, 2, and 5 years postoperatively were investigated. We assessed the Harris Hip Score and evaluated hip pain and ambulatory ability using a self-administered questionnaire.

RESULTS

The incidences of at least one fall were 30.8%, 26.2%, 23.1%, and 30.8% before and 1, 2, and 5 years after surgery, respectively. Among the circumstances of falls from pre-surgery to 5 years post-surgery, there was a significant difference in the direction of falls; however, there were no significant differences in the location, time, cause, and type of injury. Most falls occurred indoors by tripping or loss of balance during the daytime. Among the participants who had falls almost half sustained injuries, and approximately 10% of falls resulted in fractures each year. Although self-reported hip pain, ambulation, and the Harris Hip Score significantly improved in women after total hip arthroplasty compared to pre-surgery, there was no significant difference in the incidences of falls from 1 to 5 years post-surgery.

CONCLUSION

Women who underwent total hip arthroplasty continued to have an increased risk of falls and fall-induced injuries for 5 years postoperatively. Preventive measures against falling to reduce fall-induced injuries in the long term are required for women after total hip arthroplasty.

Early postoperative relationship between patient-reported outcome measures and gait biomechanical factors after total hip arthroplasty

BACKGROUND

Patient-reported outcome measures (PROMs) have recently been considered as indicating clinical outcomes after total hip arthroplasty (THA). Although various factors are reportedly associated with post-THA and PROMs, the relationship with gait parameters, which are objective assessment factors after THA, remains unclear.

RESEARCH QUESTION

What is the relationship between PROMs and gait biomechanical factors four weeks after THA?

METHODS

Forty-five patients (six men and 39 women) who underwent THA were included. Three-dimensional gait analysis was performed four weeks post-THA; joint angle, internal moment, and power of the lower extremity at the first and second peaks of the vertical component of the floor reaction force were assessed for the operated side. PROMs were evaluated using the Japanese Orthopedic Association Hip Disease Evaluation Questionnaire (JHEQ). The relationship between the JHEQ score and extracted gait parameters was analyzed using gender and gait speed as control factors.

RESULTS

For the JHEQ sub-domain, movement was positively correlated with the internal knee extension moment values at the first peak (r = 0.347). There was no significant correlation between JHEQ and the internal hip abduction moment value at the first peak. Mental status was negatively correlated with the hip flexion angle value at the second peak (r = -0.373), and positively correlated with the hip flexion moment value (r = 0.348). Total JHEQ scores and mental status were negatively correlated with the power of hip flexion value at the second peaks, respectively (r = -0.316, -0.444).

SIGNIFICANCE

The results of this study may provide recovery guidelines to be used as an index for gait assessment in the early post-THA period. Further studies are needed to verify whether gait parameters can improve PROMs in the early post-THA period.

Prevalence of locomotive syndrome in Japanese patients more than 10 years after total hip arthroplasty: A cross-sectional cohort study

BACKGROUND

Locomotive syndrome (LS) is a high risk condition that requires nursing care. It is important to investigate the prevalence of and factors related to LS to maintain a healthy life expectancy for patients; however, only a few reports have focused on the relationship between LS and total hip arthroplasty (THA). The purpose of this study was to evaluate the prevalence of LS and to identify factors associated with LS in patients more than 10 years after THA.

METHODS

This is a cross-sectional cohort study. Patients were assessed via a mail survey that included items regarding demographic data, cardiometabolic and motor disorders, the incidence of falls, physical activity level, and the 25-question Geriatric Locomotive Function Scale (GLFS-25) questionnaire. LS was defined as having a score ≥16 on the GLFS-25, and the respondents were categorized into two groups: an LS group and a non-LS group. The prevalence of LS was calculated in each gender and age group. Differences in variables between the groups were determined using the unpaired t-test and chi-squared test.

RESULTS

A total of 593 patients were included in the study (mean age, 70.4 years; 525/593 females). According to the GLFS-25, 164 patients (27.7%; 21.1% men and 28.8% women) were classified as having LS, which increased with age. In addition, compared with the non-LS group, the LS group had a significantly higher prevalence of motor diseases, cardiometabolic diseases, and falls and significantly lower levels of activity.

CONCLUSION

These findings suggest that the prevalence of LS in patients more than 10 years after THA is 27.7%. The result suggest that the prevalence of LS in patients more than 10 years after THA is similar to the prevalence of LS in the general elderly population. Furthermore, LS is related to not only motor diseases but also cardiometabolic diseases.

Effects of incorporating elliptical trainer exercise during rehabilitation on physical function and self-reported outcomes after total hip arthroplasty: a randomized controlled trial

[Purpose] To investigate the effects of incorporating elliptical trainer exercise in early rehabilitation after total hip arthroplasty on physical function and self-reported outcomes. [Participants and Methods] Participants with independent gait prior to total hip arthroplasty underwent conventional postoperative physiotherapy and were divided into two groups. The intervention group additionally underwent elliptical trainer exercise, while the control group underwent a walking program. The main outcomes were low back and hip region pain, lower limb muscle strength, single-leg stance time, Timed Up & Go Test results, 10 m walking test results, hip disability and osteoarthritis outcome score, and modified fall efficacy scale score. These outcomes were evaluated preoperatively, at discharge, and at 1 and 3 months postoperatively. [Results] Fifty participants (including 40 females; age, 68.3 ± 10.8 years) participated in this study. Physical function evaluations showed a significant improvement in hip region pain during walking at discharge. Knee extensor strength, single-leg stance time, stride length, and walking speed were significantly greater in the intervention group at discharge and at 1 and 3 months postoperatively. The modified fall efficacy scale score significantly improved in the intervention group 1 month postoperatively. [Conclusion] Elliptical trainer exercise and conventional physiotherapy in the early postoperative period contribute to improved physical function and walking ability and improvement in the fear of falling.

Benefits of Combining Physical Therapy with Occupational Therapy in Hip Arthroplasty

(1) Background: Hip arthroplasty (HA) is a surgery that replaces the damaged hip joint with an artificial implant called a hip prosthesis. The increase in life expectancy correlated with the population aging level, to which the increase in the number of prosthetic interventions among the young population is added, translates to the imperative need to analyze the quality of life beyond the immediate postoperative period. Strict adherence to an individualized rehabilitation program (IRP), and adapted to each patient, is followed by an improved quality of life. The main goal is the recovery of the patient with HA. This study was aimed to demonstrate that an IRP, represented by physical therapy associated with occupational therapy, improves the quality of life of patients with HA; (2) Methods: In this study, conducted between 2019 and 2021, 50 patients with HA were divided into two groups: study group-group A (25 subjects compliant with the IRP) and control group-group B (25 subjects, non-compliance with the IRP). To evaluate the two study groups, we monitored the evolution of the modified Harris hip score (mHHS) in both hips (arthroplasty hip (AH), contra lateral hip (CH)), for four months, respectively 30 days before the surgery (T0) and at 90 days after the surgery (T1); (3) Results: We notice significant differences in mHHS values at 90 days-T1 after surgery, both on AH in favor of subjects from group A vs. group B (p = 0.030) and on CH, where mHHS values were statistically higher in group A compared to group B (p < 0.001). The results of our study outline at T1 moment, both on the AH (p = 0.030) and on the CH (p < 0.001), the fact that mHHS values were statistically higher in patients included in group A compared to group B. In terms of the results for mHHS, comparing AH with CH, it is noted that the number of subjects who had a good or excellent mHHS result in group A versus group B is statistically significant in the case of CH (group A: 23 (92%) vs. group B: 11 (44%), p = 0.039); (4) Conclusions: The study reveals clear advantages of HA in both hips, both in subjects who complied with the IRP and those who did not comply; the higher therapeutic benefits of IRP are outlined at the level of CH compared to AH; in patients who comply with the IRP, the mHHS parameters that have improved in both CH and AH are pain, leaning, and shoes and socks activities; in addition, limping was reduced in CH.

Patients Who Present with Functional Limitations, Limited Range of Motion and Reduced Muscle Strength 6 Months after Total Hip Arthroplasty: A Cross-Sectional Study

Objective  To evaluate levels of pain, range of motion, hip isometric peak torque, and functional task performance in patients 6 months after total hip arthroplasty (THA) and to compare them to asymptomatic control participants (CG). Methods  We recruited participants with unilateral THA due to hip osteoarthritis (OA) within a median of 6 months who had not developed postoperative complications. We assessed the pain levels, hip range of motion, peak isometric torque, self-reported assessment (Harris Hip Score) and objectively measured function (Timed Up & Go Test [TUG]) of the patients. The THA group was compared with a group of asymptomatic participants ≥50 years old recruited in the community. Comparisons are presented as mean differences (MDs) and 95% confidence intervals (CIs). Results  A total of 23 participants were included in each group. Pain levels were low in the THA group (1.48 [1.60]), and 91.3% of the patients reported to be satisfied with the surgical procedure. Participants in the THA group reported significantly lower objectively measured (THA 12.2 [10.0-21.6]; CG 9.0 [6.7-12.2]) and self-reported function (THA 78.5 [43.8-93.9]; CG 100.0 [95.8-100.0]) compared with CG. The THA group also had significantly reduced range of motion for flexion ( p  < 0.001), internal ( p  < 0.001) and external rotation ( p  = 0.003) movements and reduced peak torque for flexion ( p  < 0.001), extension ( p  < 0.001), abduction ( p  < 0.001) and adduction ( p  = 0.024) movements compared with participants of the CG. Conclusions  Despite reporting overall low pain scores and satisfaction with the surgery, the patients present with functional limitations, limited range of motion, and reduced muscle strength 6 months after THA. Evidence Level 3b.

A predictive model for hip abductor strength and knee extensor strength 12 months after total hip arthroplasty with an interaction term

Background

Identifying populations with poor muscle recovery after total hip arthroplasty (THA) is important for postoperative physical therapy. Preoperative muscle strength is a strong factor that determines postoperative muscle strength. However, this effect may depend on other factors. Thus, predictive models with interaction terms are important for accurately predicting postoperative muscle strength. This study aimed to develop a predictive model for lower muscle strength 12 months after THA which incorporates interaction terms.

Methods

Subjects were female patients with hip osteoarthritis who underwent unilateral THA. Patients with locomotor disorders, neurological disorders, or postoperative complications were excluded. Hip abductor and knee extensor strength were measured, and a generalized linear model approach with preoperative muscle strength, age, body weight, height, disease duration, physical activity, and leg extension as explanatory variables was used to identify factors that determine muscle strength 12 months after THA. Models with interaction terms between preoperative muscle strength and other explanatory variables were also examined.

Results

A total of 82 patients were analyzed. Preoperative muscle strength, age, body weight, physical activity, and disease duration were extracted as factors that significantly and independently determine hip abductor and knee extensor strength. The interaction term between preoperative muscle strength and age was identified as a factor that significantly determines knee extensor strength. Regression coefficients for preoperative knee extensor strength and postoperative muscle strength were significant when age was +1 SD, but not when age was -1 SD.

Conclusions

The predictive model demonstrated that lower muscle strength 12 months after THA is determined by preoperative muscle strength, age, weight, physical activity, disease duration, and preoperative muscle strength, with the effect of preoperative muscle strength on knee extensor strength being dependent on age. When predicting postoperative knee extensor strength using preoperative muscle strength, it is important to consider the effect of age.

Prevalence of frailty and associated factors among community-dwelling older adults after total hip arthroplasty

OBJECTIVE

To evaluate the prevalence of frailty and associated factors among community-dwelling older adults who have undergone total hip arthroplasty (THA).

MATERIALS AND METHODS

This study, which employed a cross-sectional, observational design, was conducted between April and November 2020. The participants were older adults (⩾65 years) who had undergone primary THA at the study hospital. Based on Fried's modified phenotype, frailty was stratified into 3 degrees according to the presence of 3 or more of the following components: weight loss, weakness, exhaustion, low activity level, and slow walking speed. Multinomial logistic regression was used to analyse the associations of frailty with its potential risk factors.

RESULTS

The data of 518 participants were analysed. The overall prevalence of frailty and prefrailty was 11.4% and 51.0%, respectively. The multinomial logistic regression analysis showed that calf circumference (odds ratio [OR] 0.716, 95% confidence interval [CI], 0.611-0.839; p < 0.001), fall history (OR 2.435, 95% CI, 1.114-5.322; p = 0.026), hip abductor muscle strength (OR 0.962, 95% CI, 0.938-0.987; p = 0.003), knee extensor muscle strength (OR 0.980, 95% CI, 0.964-0.996; p = 0.013), and Timed Up and Go test (TUG) performance (OR 1.802, 95% CI, 1.458-2.228; p < 0.001) were associated with frailty.

CONCLUSIONS

Frailty was highly prevalent in community-dwelling older adults after THA. Further, its potential associations with calf circumference, hip abductor and knee extensor muscle strength, TUG performance, and fall history highlight the significance of these factors for interventions.

Multivariate functional principal component analysis identifies waveform features of gait biomechanics related to early-to-moderate hip osteoarthritis

Clinicians often examine movement patterns to design hip osteoarthritis (OA) interventions, yet traditional biomechanical analyses only report a single timepoint. Multivariate principal component analysis (MFPCA) analyzes the entire waveform (i.e., movement pattern), which clinicians observe to direct treatment. This study investigated hip OA indicators, by (1) employing MFPCA to characterize variance across the hip, knee, and ankle angles in healthy and early-to-moderate hip OA participants; and (2) investigating relationships between these waveform features and hip cartilage health. Bilateral hip magnetic resonance images from 72 participants with Kellgren-Lawrence grades ranging from 0 to 3 were used to calculate mean T _1ρ and T ₂ relaxation times in the femoral and acetabular cartilage. MFPCA was performed on lower-limb gait biomechanics and used to identify primary modes of variation, which were related to T _1ρ and T ₂ relaxation times. Here, a MFPC = mode of variation = waveform feature. In the femoral cartilage, transverse plane MFPCs 3 and 5 and body mass index (BMI) was related to T _1ρ , while MFPC 2 and BMI were related to T ₂ relaxation times. In the acetabular cartilage, sagittal plane MFPC 1 and BMI were related to T _1ρ , while BMI was related to T ₂ relaxation times. Greater internal rotation was related to increased T _1ρ and T ₂ relaxation times in the femoral cartilage, while the greater extension was related to increased T _1ρ relaxation times in the acetabular cartilage. This study established a data-driven framework to assess relationships between multi-joint biomechanics and quantitative assessments of cartilage health and identified waveform features that could be evaluated in future hip OA intervention studies.

Abductor Muscle Strength Deficit in Patients After Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

The aims of this study were to assess and quantify hip abductor muscle strength deficits after total hip arthroplasty (THA) and to determine associations with external factors.

METHODS

Studies reporting on hip abductor muscle strength before and/or after THA performed for osteoarthritis or atraumatic osteonecrosis of the hip were considered for inclusion. Data sources were Embase, Medline, and the Cochrane Central Register of Controlled Trials. Muscle strength on the affected side was compared with the healthy contralateral side or with control subjects. Study quality was assessed using a modified Newcastle-Ottawa Scale.

RESULTS

Nineteen studies reporting on 875 subjects met the inclusion criteria. Patients scheduled for THA had a mean strength deficit of 18.6% (95% confidence interval (CI) [-33.9, -3.2%]) compared with control subjects. Abductor muscle strength then increased by 20.2% (CI [5.6, 34.8%]) at 4-6 months, 29.6% (CI [4.7, 54.4%]) at 9-12 months, and 49.8% (CI [-31.0, 130.6%]) at 18-24 months postoperatively compared with preoperative values. For unilateral THA, the mean torque ratio was 86.3% (CI [75.4, 97.2%]) and 93.4% (CI [75.1, 111.6%]) before and >24 months after THA, respectively. Study quality was low to moderate.

CONCLUSION

Hip abductor muscle strength deficits may gradually improve during 24 months after THA possibly without complete recovery. Cautious interpretation of these findings is warranted because high-quality evidence is largely missing.

The efficacy of total hip arthroplasty on locomotive syndrome and its related physical function in patients with hip osteoarthritis

BACKGROUND

Locomotive syndrome (LS) is a predictive factor of future motor dysfunction. Our aim was to evaluate the change in the total LS grade and, its the association with the Japanese Orthopaedic Association (JOA) hip score after total hip arthroplasty (THA) among patients with hip osteoarthritis.

METHODS

This was a prospective case-control study of 72 patients who underwent primary THA. The functional outcomes were measured before, and at 6 and 12 months after THA. LS was evaluated using the following tests: stand-up test, 2-step test, and 25-question Geriatric Locomotive Function Scale (GLFS-25). In addition, factors affecting the improvement of LS grade were examined.

RESULTS

Prior to THA, 7% and 93% of patients were classified as LS grades 1 and 2. At 6 months after THA, an improvement in the total LS grade was observed in 57% of patients, with this percentage further increasing to 65% at 1 year. Only the preoperative GLFS-25 was correlated with the preoperative JOA hip scores. The postoperative GLFS-25 and the two-step test were correlated with the postoperative JOA hip scores. The preoperative functional reach test (FRT) was significantly correlated with the total LS grade improvement.

CONCLUSIONS

THA can improve the total LS grade in 65% of patients at 1 year postoperatively. Improvement was largely achieved in the first 6 months after THA, with a change from LS grade 2 to grade 1. FRT could be used an indicator of the total LS grade improvement.

Validation of the Muscle Tightness Measurement Tool

BACKGROUND AND PURPOSE

For nurses, muscle tightness is an important aspect of patient care, but no bedside tool is available that allows them to measure it. Therefore, a standardized tool that measures muscle tightness is needed. The purpose of this study was to validate a tool to measure muscle tightness.

METHODS

Using Delphi technique and quantitative design, the tool was validated in two phases. The phase 1 included 20 expert clinicians who established content validity with Lawshe's rating. In phase 2, divergent validity was established by administering the tool to one group that had muscle tightness (n = 26) and one group that did not (n = 20).

RESULTS

Findings indicate that the muscle tightness measurement tool has content and divergent validity.

CONCLUSIONS

Further tool refinement with validity and reliability studies are recommended for clinical practice.

Abductor Muscle Force after Straight-Stem Compared to Short-Stem Total Hip Arthroplasty through a Modified Direct Lateral Approach: Functional Assessment of 70 Consecutive Patients of a Randomized Controlled Clinical Trial

Because of preservation of proximal femoral bone stock and minimized soft tissue trauma, short-stem implants are becoming increasingly important in total hip arthroplasty (THA). The postulated advantage regarding the functional outcome has not been verified. We hypothesized an increased abductor muscle strength by the use of a short-stem design. Seventy consecutive patients of a randomized clinical trial were included. Of these, 67 patients met the inclusion criteria after 12 months. Thirty-five patients received a standard straight stem and 32 patients a short-stem femoral component. All surgeries were performed by a modified direct lateral approach. Isometric muscle strength of the hip abductors was evaluated preoperatively 3 and 12 months after surgery. Harris hip score (HHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were evaluated. After three months, there were no differences between the two groups; the abductor force was comparable to the preoperative initial values. After 12 months, a significant increase in muscle strength for the short stem patient group compared to preoperative baseline values was measured (straight-stem THA, 0.09 Nm/kg ± 0.4, p = 0.32; short-stem THA, 0.2 Nm/kg ± 0.3, p = 0.004). Comparison of the 12-month postoperative total HHS and WOMAC revealed no significant differences between both groups. A significant increase in hip abductor muscle strength 12 months after short-stem THA compared to conventional-stem THA was observed.

Walking energetics and abductor strength are associated with physical activity in older women with hip osteoarthritis

BACKGROUND

Osteoarthritis (OA) can hinder physical activity in older adults for reasons that are not fully understood. Functional barriers may exist such as reduced muscle strength around the affected joint, potentially affecting physical activity. Aging-associated declines in energy capacity may also be exacerbated by OA. These factors may work together to influence physical activity in people with OA.

RESEARCH QUESTION

Our objective was to evaluate the combined role of walking energetics and hip abductor strength on physical activity in older women with hip OA.

METHODS

We evaluated 30 women with moderately symptomatic hip OA (61 ± 10 yrs; 30.7 ± 4.9 kg/m²) in this cross-sectional observational study. We measured physical activity using the UCLA activity score and quantified activity frequency and intensity using accelerometers worn for seven days (7 ± 2 days). We used a portable oxygen exchange system to measure energy used during walking at preferred speeds (relative to total energy capacity assessed using a six-minute walk test) and a dynamometer to measure hip abductor strength. We used Pearson correlations and regression analysis to test our hypotheses.

RESULTS

Greater energy used during walking was associated with lower self-reported physical activity (R=-0.626, p < 0.001), more sedentary time (R = 0.567, p = 0.002), and less light activity time (R=-0.644, p < 0.001). Lower hip abductor strength was associated with lower self-reported physical activity (R = 0.406, p = 0.039). While there was no association between hip abductor strength and energy used during walking, together these variables predicted 55.5 % of the variance in self-reported physical activity.

SIGNIFICANCE

Results suggest intervention targets to promote physical activity in this population.

Persisting inter-limb differences in patients following total hip arthroplasty four to five years after surgery? A preliminary cross-sectional study

BACKGROUND

Total hip arthroplasty (THA) is an effective procedure for patients with end-stage hip osteoarthritis. However, whether or not pre-operatively existing functional deficits are persisting several years post-surgery in the affected limb has not been thoroughly researched. Therefore, the primary aim of this preliminary study was to include patients four to five years after undergoing THA and to investigate potential differences between the operated and non-operated leg in hip strength, range of motion (ROM), balance, and gait. The secondary aim was to compare these values from the operated leg of the patients to those of the legs of healthy subjects.

METHODS

Sixteen patients (age: 65.20 ± 5.32 years) following unilateral THA (post-operation time: 4.7 ± 0.7 years) and ten, healthy, age-matched control subjects (age: 60.85 ± 7.57 years) were examined for maximum isometric hip muscle strength, active ROM of the hip joint, balance and gait on both limbs. Paired t-tests were used to assess the inter-limb differences in the THA group. Analyses of covariance (ANCOVA) were performed to compare groups, using age as a covariate.

RESULTS

The analysis of inter-limb differences in patients following THA revealed significant deficits on the operated side for hip abduction strength (p = 0.02), for hip flexion ROM (p < 0.01) and for balance in terms of the length of center of pressure (COP) (p = 0.04). Compared to values of the control subjects, the patients demonstrated significantly reduced hip strength in flexion, extension and abduction (p < 0.05) on the operated leg as well as reduced ROM measures in hip flexion, extension and abduction (p < 0.05).

CONCLUSIONS

The first results of this explorative study indicated that inter-limb differences as well as reduced hip strength and hip ROM compared with control subjects were still present four to five years after THA. These persisting asymmetries and deficits in patients following THA may be one explanation for the decrease in health-related quality of life (HRQoL) seen in patients over the years after surgery. Further studies are required to replicate these findings with a larger sample size.

TRIAL REGISTRATION

DRKS, DRKS00016945. Registered 12 March 2019 - Retrospectively registered.

Evaluation of muscle volume and degeneration after total hip arthroplasty: a comparison of the posterolateral approach and the anterolateral supine approach

Background

Muscle strength around the hip after total hip arthroplasty (THA) is crucial for preventing dislocation and limping. This study aimed to assess and compare muscle volume and degeneration after THA using the posterolateral (PL) and anterolateral (AL) approaches.

Methods

Sixty-four hips in 64 patients who underwent primary THA were retrospectively analyzed. Patients were segregated into the PL group (35 hips) and AL group (29 hips) for evaluating pre- and postoperative muscle volumes and degeneration around the hip. Computed tomography (CT) examinations were performed preoperatively and 6 months post THA. The muscle volume and Hounsfield units (HU) of the gluteus maximus (G-max), gluteus medius (G-med), tensor fasciae latae, internal obturator muscle, and external obturator muscle were measured.

Results

In the PL group, the postoperative muscle volume of the G-max significantly increased than the preoperative muscle volume. In contrast, the postoperative muscle volume of the internal obturator muscle was significantly lower than the preoperative muscle volume. The postoperative HU of the internal and external obturator muscles were significantly lower than the preoperative HU. In the AL group, the postoperative muscle volumes of the G-max, G-med, and tensor fasciae latae significantly increased than their preoperative muscle volumes. The postoperative HU of the G-med and tensor fasciae latae were significantly higher than the preoperative HU values.

Conclusion

The PL approach can lead to degeneration of the internal and external obturator. The AL approach is more beneficial for recovering the G-med, tensor fasciae latae, and internal obturator muscle than the PL approach.

Kinematic and Kinetic Changes after Total Hip Arthroplasty during Sit-To-Stand Transfers: Systematic Review

Background

Total hip arthroplasty (THA) is a common and effective surgical procedure that allows patients with hip osteoarthritis to restore functional ability and relieve pain. Sit-to-stand transfers are common demanding tasks during activities of daily living and are performed more than 50 times per day. The purpose of this systematic review is to obtain a comprehensive understanding of biomechanical changes during sit-to-stand transfers after THA.

Methods

Relevant articles were selected through MEDLINE, Scopus, Embase, and Web of Science. Articles were included if they met the following inclusion criteria: 1) participants underwent total hip arthroplasty without restriction on the arthroplasty design, 2) involved either kinematic or kinetic variables as the primary outcome measure, 3) evaluated sit-to-stand, and 4) were written in English.

Results

A total of 11 articles were included in the current systematic review. The THA group exhibited altered movement patterns as compared to healthy controls. Improvement in loading asymmetry was found up to 1 year after THA, but other kinetic changes indicate intensified contralateral limb loading. Limb differences were apparent, but whether these differences persist over 10 months after THA is still unknown.

Conclusion

Despite the inevitable changes in kinematics and kinetics in sit-to-stand transfers after THA, it appears to be important to resolve asymmetrical loading between the operative and nonoperative limbs to minimize risk for subsequent joint problems.

The effect of gait training with low-intensity neuromuscular electrical stimulation of hip abductor muscles in two patients following surgery for hip fracture: Two case reports

Background: The rate of force development (RFD) is an indicator of muscle strength. A previous study reported that the RFD of hip abductor muscles was increased by neuromuscular electrical stimulation (NMES) to gluteus medius (GM) during gait in healthy adults. However, the effects for patients following femoral head replacement for hip fracture are unclear.Purpose: The aim of this case report was to investigate the effects of gait training with sub-motor threshold NMES on RFD of hip abductor muscles in two patients following femoral head replacement for hip fracture compared to gait training without NMES.Case description: Two elderly patients following femoral head replacement for hip fracture received both interventions of gait training with sub-motor threshold NMES to GM and without NMES. Intervention phases involved 14 sessions each, for 28 sessions total.Outcomes: The RFD of hip abductor muscles, maximum walking speed, six-minute walk distance (6MWD), Berg Balance Scale, one-leg standing time (OLST), functional independence measure, and Numeric Pain Rating Scale (NPRS) were used as outcome measures. In both patients, RFD, 6MWD, OLST, and NPRS were improved by gait training with NMES compared to without NMES.Conclusion: Our results suggest the potential of NMES as a treatment methodology for these two patients undergoing femoral head replacement for hip fracture.

Incidence of postoperative complications and non- periprosthetic fractures after total hip arthroplasty: A more than 10-year follow-up retrospective cohort study

OBJECTIVE

Postoperative complications and non-periprosthetic fractures (NPPFs), which was defined as a fracture existing non- periprosthetic implant, after total hip arthroplasty (THA) have a negative effect on the patients' ability to perform activities of daily living. Thus, investigating these incidences of patients after THA will be valuable as it lead to a more strategic physical therapy interventions and advanced research to prevent these problems. The purpose of this study was to investigate the incidence of postoperative complications related to implants and NPPFs in patients after THA, a more than 10-year follow-up.

METHODS

This is a retrospective cohort study. A total 892 patients with hip osteoarthritis who underwent primary THA were analyzed (age at surgery was 45-79 years; 805 women; the average follow-up period was 12.4-year). The postoperative complications related to implants and NPPFs were calculated using data from their medical records.

RESULTS

The postoperative complications occurred in 37 patients, and NPPFs occurred in 72 patients, who were significantly older, and hip and knee OA diagnosis, compared to patients without NPPFs ( p <.05). The most common cause of NPPFs was minor trauma. In patients aged ≧ 65 years, significantly more NPPFs occurred during the first year after surgery( p <.05).

CONCLUSION

More than 10-year after THA, the incidence of NPPFs was higher than that of postoperative complications related to implants. Older patients who had hip and knee OA were a significantly higher risk of developing NPPFs due to falls within the first year after surgery.

Improvement of locomotive syndrome after total hip arthroplasty: A two-year longitudinal cohort study

OBJECTIVES

Patients requiring total hip arthroplasty (THA) may possibly have locomotive syndrome (LS). Therefore, we investigated changes of LS in patients undergoing THA and clarified key factors that affected LS stage.

METHODS

A prospective cohort study was conducted with 88 patients undergoing THA (74 females, 14 males, mean age: 67.6 years). Data collected using LS stage, stand-up test, two-step test, and 25-question Geriatric Locomotive Function Scale results were evaluated before THA, and 6 months, 1 year, and 2 years after THA. Key factors were determined using multivariate analysis and receiver operating characteristic (ROC) curve analysis.

RESULTS

Before THA, all patients had fallen LS (stage1: 3.4% and stage2: 96.6%). Overall, 56.8% patients improved their LS stage, and 17.0% of patients overcame LS at 2 years after THA. The key factors that affected LS stage were preoperative two-step test and age. ROC analyses showed a preoperative two-step test score of 0.988 and an age of 67.5 years as a cut-off value for the change of LS stage.

CONCLUSIONS

Patients experiencing LS due to hip disorders have the potential to recover after THA. Additional postoperative training may be beneficial for patients with low preoperative two-step test scores to improve their LS stage.

Predictors of falls in patients during the first year after total hip arthroplasty: A prospective cohort study

BACKGROUND AND PURPOSE

Since falls after total hip arthroplasty (THA) cause severe complications such as dislocation and fractures around the femoral stem, it is important to investigate what factors predict of falls. Thus, investigating predictors of falls in patients waiting for THA would be valuable as it lead to more strategic interventions to prevent these problems. The purpose of this study was to evaluate the predictors of falls in patients during the first year after THA.

METHODS

This is a prospective cohort study. A total of 157 patients who underwent THA for unilateral hip osteoarthritis were analyzed. The incidence of falls during the first year after THA was monitored, and patients were classified into a "faller" and "non-faller" group. The following factors were compared between the two groups: demographic data (age, sex, body mass index, leg length discrepancy, length of hospital stay, and history of falling), preoperative hip abductor muscle strength, functional performance (single leg stance and maximum walking speed), pain during walking, and physical activity.

RESULTS

On multivariate logistic regression analysis, preoperative hip abductor muscle strength on the affected side and a history of falling were predictors of falls during the first year after THA. On subsequent receiver operating characteristic curve analysis, preoperative hip abductor muscle strength on the affected side was retained as a significant predictor, with a cut-off strength of 0.46 Nm/kg differentiating the faller and non-faller groups with a specificity of 73.6%, specificity of 50.0%, and area under the curve of 70.2%.

CONCLUSIONS

Finding from the present study suggested that clinicians should focus on low preoperative hip abductor muscle strength on the affected side and a history of falling to prevent falls during the first year after THA.

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

BACKGROUND

Little is known about the relationship between vertical ground reaction force (vGRF) and muscle strength while climbing stairs after total hip arthroplasty (THA).

METHODS

We investigated the relationship between muscle strength and vGRF during stair climbing in 21 women with THA. Differences in the time required to climb stairs and side-to-side differences in muscle strength and vGRF during climbing were examined at 6 and 12 months. The relationship between climbing time and vGRF variables and that between vGRF and muscle strength were analyzed using Spearman's rank correlation coefficient at 6 and 12 months. First peak force (Fz1) was defined as the peak vGRF at heel strike normalized by body weight.

FINDINGS

Climbing time was related to the time to Fz1 at 6 and 12 months post-THA (r = 0.50-0.64). At 6 months, time to Fz1 was related to the strength of muscles involved in hip extension in the operated limb (r = -0.46). At 12 months, time to Fz1 was related to the strength of muscles responsible for knee extension in the operated limb (r = -0.45).

INTERPRETATION

At 6 months, climbing stairs depended on muscle strength in the hip extensors. Conversely, at 12 months, the functional recovery of knee extensors was important for transferring weight upward while climbing stairs. Therefore, to improve the climbing function of patients with THA, it is important to not only focus on the recovery of muscle strength in the hip extensors but also improve muscle strength in the knee extensors.

Abductor muscle strength deficit in patients after total hip arthroplasty for hip osteoarthritis: a protocol for a systematic review and meta-analysis

INTRODUCTION

Conservation of abductor muscle strength is directly associated with physical function after total hip replacement (THA). Although many studies have tried to explore and quantify a potential abductor muscle strength deficit after THA as well as identify possible causes and treatment options, this topic has not been addressed systematically.

METHODS AND ANALYSIS

Human-based studies reporting measurements of hip abductor strength will be included in this review. Studies reporting on hip abductor strength measured manually or isometric measurements at an abduction angle other than 0° will not be considered. No restriction will be placed on study design, publication date operative approach, prosthesis design, age and sex of the patients or severity of OA. Data sources will be Embase via embase.com, Medline ALL via Ovid and the Cochrane Central Register of Controlled Trials. The preliminary search was conducted on 5 May 2019. Data regarding absolute values or torque ratio of hip abductor torque between sides as well as patient demographic data, surgical approaches and rehabilitation protocols will be extracted. The assessment of quality and risk of bias will be performed with the modified Newcastle-Ottawa Scale. The screening, data extraction and quality assessment will be performed by two reviewers independently. Where necessary, a third review author will make a final judgement. Narrative synthesis as well as tabular presentation of the extracted data will be included. Whenever possible, metaregression and subgroup specific meta-analyses will be used to investigate the influence of time since THA and type of measurement (isokinetic or isometric) on the different outcomes. In case of sufficient information, these analyses will be extended to include characteristics such as age, sex, surgical approach or rehabilitation programme.

ETHICS AND DISSEMINATION

No ethics approval is required. The results will be disseminated through peer-reviewed publications and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42020153185.

Prevalence and Risk Factors of Falls in Adults 1 Year After Total Hip Arthroplasty for Osteoarthritis: A Cross-Sectional Study

Total hip arthroplasty is very successful in alleviating the pain from osteoarthritis. However, deficits in lower limb strength, gait, and balance after surgery has identified this group at risk of falls. Considering the high number of people annually receiving a total hip arthroplasty, further elaboration of factors associated with falls is needed to refine fall prevention guidelines. The objective was to examine the prevalence and circumstances of falling and the risk factors associated with falling in older adults in the first year after total hip arthroplasty surgery. This was a cross-sectional study involving 108 individuals (age of 72.4 ± 6.5 yrs, 60% females) who had unilateral total hip arthroplasty. The primary outcome was falls and their circumstances during the 12 mos after the total hip arthroplasty. Twenty-five people (23.1%) had at least one fall and most falls (56%) occurred 6-12 mos after surgery. Falls resulted in minor injuries for 44% and 12% reported major injuries. The strongest independent predictor for falls was a history of a previous joint replacement with odds ratio of 7.38 (95% CI = 2.41-22.62, P < 0.001). Overall, the information highlights that falls are common after total hip arthroplasty, yet considering the older age of people having this surgery screening for falls risk should follow established guidelines.

Comparison of Clinical Outcomes, Radiological Outcomes and Bone Remodeling Outcomes Between Proximal Coated Single-Wedge New Stem and Full Coated Dual-Wedge Classic Stem in 1-Stage Bilateral Total Hip Arthroplasty

Background

This retrospective study investigated the clinical outcomes, radiological outcomes, and bone remodeling patterns associated with a Medial/Lateral Taper (M/L Taper) stem and Link Classic Uncemented (LCU) stem in 1-stage bilateral total hip arthroplasty (THA).

Material/Methods

The results of 52 patients who underwent 1-stage bilateral THA with a M/L Taper stem on one side and an LCU stem on the other between January 2012 and February 2015 were retrospectively compared. Patients were clinically assessed by the Harris hip score (HHS), visual analogue score (VAS) and incidence of complications. Radiological indicators were measured. Periprosthetic bone remodeling was assessed via bone mineral density (BMD) measurements.

Results

The mean follow-up time was 5.2 years. At each follow-up, there was no difference in the HHS and VAS between the 2 groups. The neck-shaft angle, offset, vertical height of the rotational center and limb lengthening were lower in the M/L Taper group than in the LCU group (P<0.001). The Engh total score was lower in the LCU group (P=0.039). Significantly higher (P<0.001) BMDs were observed in the M/L Taper group in Gruen zones 1, 2, and 6. significantly lower (P<0.001) BMDs were observed in the M/L Taper group in Gruen zones 3 and 5.

Conclusions

Due to the increased postoperative neck-shaft angle, the full coated dual-wedge classic stem was prone to cause lower limb lengthening. The proximal coated single-wedge new stem patients were more likely to have an insufficient postoperative neck length. The new stem achieved load transfer and proximal fixation, leading to better proximal femoral bone preservation is more in line with human biomechanical characteristics.