Gait Patterns After Total Hip Arthroplasty and Surface Replacement Arthroplasty

Influence of Skin Marker Positioning and Their Combinations on Hip Joint Center Estimation Using the Functional Method

Accurate estimation of hip joint center (HJC) position is crucial during gait analysis. HJC is obtained with predictive or functional methods. But in the functional method, there is no consensus on where to place the skin markers and which combination to use. The objective of this study was to analyze how different combinations of skin markers affect the estimation of HJC position relative to predictive methods. Forty-one healthy volunteers were included in this study; thirteen markers were placed on the pelvis and hip of each subject's lower limbs. Various marker combinations were used to determine the HJC position based on ten calibration movement trials, captured by a motion capture system. The estimated HJC position for each combination was evaluated by focusing on the range and standard deviation of the mean norm values of HJC and the mean X, Y, Z coordinates of HJC for each limb. The combinations that produced the best estimates incorporated the markers on the pelvis and on proximal and easily identifiable muscles, with results close to predictive methods. The combination that excluded the markers on the pelvis was not robust in estimating the HJC position.

Gait analysis and clinical outcome in patients after pilon fracture surgery

BACKGROUND

In this study kinematic parameters, radiographic findings and PROM in pilon fractures after operative treatment were compared with healthy subjects.

METHODS

16 patients treated with osteosynthesis after pilon fracture underwent kinematic analysis with the OFM. Fractures were evaluated for post-operative step-off and gap on CT-scans and PROM were collected. Results were compared to 10 healthy persons.

RESULTS

Range of motion (ROM) crural was lower in the flexion/extension for pilon fractures (10.03 vs. 13.15, p = 0.017). The ROM in the inversion/eversion was low, but ROM in the abduction/adduction was higher. Correlations were found between flexion/extension and AO-classification (r = -0.357 p < 0.05), PROM score of the AOFAS (r = 0.445 p < 0.01), post-operative gap and step-off in the tibia plafond.

CONCLUSION

Pilon fractures showed decreased ROM between the hindfoot and tibia in the sagittal and transverse plane, but increased ROM in the frontal plane during push-off phase as compensatory kinetics. ROM showed significant correlations with PROM and intra-articular step-off and gap in the tibia plafond.

Balance Remains Impaired after Hip Arthroplasty: A Systematic Review and Best Evidence Synthesis

Background: Hip arthroplasty (HA) is the most common intervention for joint replacement, but there is no consensus in the literature on the real influence of this procedure on balance, or on what factors in the pre-operative, surgical, and post-operative stages may affect it. Purpose: To synthesize the evidence on how Hip Arthroplasty (HA) affects balance, identifying pre-operative, surgical, and postoperative risk factors that may impair balance in HA patients, with the aim to improve patients’ management strategies. Methods: A literature search was performed on PubMed, PeDRO, and Cochrane Collaboration on 25 May 2021. Inclusion criteria: clinical report of any level of evidence; written in English; with no time limitation; about balance changes in hip osteoarthritis (OA) patients undergoing HA and related factors. Results: 27 papers (391 patients) were included. Overall, the evidence suggested that balance is impaired immediately after surgery and, 4–12 months after surgery, it becomes better than preoperatively, although without reaching the level of healthy subjects. A strong level of evidence was found for hip resurfacing resulting in better balance restoration than total HA (THA), and for strength and ROM exercises after surgery positively influencing balance. Conclusion: Both the surgical technique and the post-operative protocols are key factors influencing balance; thus, they should be carefully evaluated when managing hip OA in patients undergoing HA. Moreover, balance at 4–12 months after surgery is better than preoperatively, although without reaching the level of the healthy population. Attention should be paid in the early post-operative phase, when balance may be impaired in patients undergoing HA.

The influence of size and comminution of the posterior malleolus fragment on gait in trimalleolar ankle fractures

BACKGROUND

Ankle fractures involving the posterior malleolus generally lead to worse outcome. However, no studies on gait in trimalleolar ankle fractures have evaluated the influence of size and comminution of the posterior malleolar fragment.

METHODS

We expected patients with more severely comminuted posterior malleolus, more severe fracture type and larger posterior fragment to have reduced gait kinematics and poorer patient-reported outcomes. 26 trimalleolar ankle fracture patients were compared with 14 healthy controls and kinematically analyzed using the Oxford Foot Model. Functional outcome was based on 4 patient reported outcome questionnaires. Effects of posterior fragment size, comminution and Haraguchi fracture classification were determined on conventional and 3D CT-scans.

FINDINGS

Trimalleolar patients had lower walking speed and reduced range of motion between the hindfoot and tibia in both loading and push-off phases in the sagittal and transverse planes. The range between the hindfoot and tibia in the sagittal plane in the push-off phase correlated significantly with patient reported outcomes. The absolute and relative surface area of the posterior fragment on conventional CT-scans and 3D CT-scans, correlated significantly with range of motion. Patients with a posterior malleolus size >10% of the posterior malleolus had lower flexion-extension between forefoot and hindfoot during loading phase than patients with a size ≤10%.

INTERPRETATION

Trimalleolar fractures reduce walking speed and range of motion in the talocrural joint. Reduced range in the talocrural joint is associated with poorer outcomes. Posterior fragment size correlated significantly with range of motion in talocrural and midfoot joints and with patient reported outcomes.

LEVEL OF EVIDENCE

Level 3, retrospective study.

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.

Prediction of Bone Mineral Density (BMD) Adaptation in Pelvis-Femur Model with Hip Arthroplasties

The prediction of bone remodeling behaviour is a challenging factor in encouraging the long-term stability of hip arthroplasties. The presence of femoral components modifies the biomechanical environment of the bone and alters the bone growth process. Issues of bone loss and gait instability on both limbs are associated with the remodeling process. In this study, finite element analysis with an adaptive bone remodeling algorithm was used to predict the changes in bone mineral density following total hip and resurfacing hip arthroplasty. A three-dimensional model of the pelvis–femur was constructed from computed tomography (CT-based) images of a 79-year-old female patient with hip osteoarthritis. The prosthesis stem of the total hip arthroplasty was modelled with a titanium alloy material, while the femoral head had alumina properties. Meanwhile, resurfacing of the hip implant was completed with a cobalt-chromium material. Contact between the components and bone was designed to be perfectly bonded at the interface. Results indicate that the bone mineral density was modified over five years on all models, including hip osteoarthritis. The changes of BMD were predicted as being high between year zero and year one, especially in the proximal region. Changes were observed to be minimal in the following years. The bone remodeling process was also predicted for the non-operated femur. However, the adaptation was lower compared to the operated limbs. The reduction in bone mineral density suggested the bone loss phenomenon after a few years.

Well-Placed Acetabular Component Oriented Outside the Safe Zone During Weight-Bearing Daily Activities

Background: A comprehensive and thorough understanding of functional acetabular component orientation is essential for optimizing the clinical outcome after total hip arthroplasty (THA). This study aimed to quantify the functional acetabular anteversion and inclination of unilateral THA patients during walking and static standing and to determine whether the functional acetabular orientation falls within the Lewinnek safe zone. Methods: Seventeen patients with unilateral THA received a CT scan and dual fluoroscopic imaging during level walking and static standing to evaluate in vivo hip kinematics. The pelvic functional coordinate system of the 3D CT-based computer model was defined by the line of gravity and anterior pelvic plane (APP) to measure functional acetabular anteversion and inclination in different postures. The Lewinnek safe zone was used to determine the acetabular malposition during functional activities. Results: The THA side demonstrated an average of 10.1° (± 9.6°, range -7.5° to 29.9°) larger functional anteversion and 16.0° (± 9.2°, range -7.2° to 29.9°) smaller inclination than native hips during level walking. Functional acetabular anteversion in the THA side during level walking and static standing was significantly larger than anatomical measurements (p < 0.05). Acetabular orientation of most well-placed THA components anatomically in the Lewinnek safe zone fell outside the safe zone during more than half of the gait cycle and static standing. Conclusion: The current study revealed that an anatomically well-placed acetabular cup does not guarantee a well-functional orientation during daily activities. The in vivo mechanical performance and loading conditions of the THA component during other weight-bearing activities should be investigated in further studies.

High-level judo practice after hip resurfacing

BACKGROUND AND HYPOTHESIS

The ability to participate in sports after hip arthroplasty is increasingly being requested by patients. The possibilities of participating in sports such as judo after hip arthroplasty have not been explored sufficiently even though these sports are associated with a high risk of loosening, dislocation or revision. The aim of this study was to evaluate the return to judo after hip resurfacing arthroplasty (HRA) in terms of time and level of practice in an expert population and to determine the surgical complication rate.

MATERIALS AND METHODS

This was a retrospective observational study of all licensed judo practitioners at an expert level (≥black belt 3rd Dan) who underwent HRA. Patients filled out a sport-specific questionnaire that captured their level of judo practice (international, national, regional, recreational), type of practice (teaching, technical recreational, competitive recreational), dan grade, weekly volume of practice and time elapsed after surgery before resuming judo. The features of the return to judo were analyzed (technical, ground, combat).

RESULTS

Sixty-seven HRA were implanted in 60 patients: 11 were international judokas, 3 were national, 8 were regional and 38 were recreational. The case series consisted of 18 patients who were 3rd Dan, 18 were 4th Dan, 7 were 5th Dan, 5 were 6th Dan and 12 were 7th Dan. The average follow-up was 65.3 months (range 9.9-11.9). All the clinical scores pointed to clinically and statistically significant improvement. Of the 60 patients, 53 had resumed judo at the final assessment (90%) after a mean of 4 months (2-7) for technical judo, 6 months (3-10) for ground judo and 7 months (3-12) for combat judo. Of those who did not resume their judo practice, 3 patients voluntarily changed sports, 2 had psychological apprehension and 2 had residual groin pain. The weekly volume of practice preoperatively was 0.9hours (0-5) and postoperatively it reached 5hours (2-18) (P<0.001).

CONCLUSION

HRA in a population of high-level judokas allows for return to sport practice without short-term complications such as fracture, dislocation or loosening.

LEVEL OF EVIDENCE

III.

Patients with hip resurfacing arthroplasty are not physically more active than those with a stemmed total hip

Background and purpose - Hip resurfacing arthroplasty (HRA) was designed for the highly active patient because of the various theoretical advantages compared with stemmed total hip arthroplasty (THA), but has shown high failure rates. Physical activity (PA) after arthroplasty is frequently determined with the use of questionnaires, which are known for their subjective nature, recall bias, and ceiling effect. These disadvantages are not applicable to physical activity monitoring (AM) using sensors. We compared objectively measured PA at long-term follow-up in a matched cohort of HRA and stemmed THA subjects.Patients and methods - We compared 2 groups of 16 patients (12 males) in each group, one having received unilateral HRA (median age 56 years at surgery) and a matched group having received unilateral stemmed THA with a small diameter femoral head (28 mm) on conventional polyethylene (median age 60 years at surgery) with osteoarthritis as indication for surgery, 10 years after surgery. Groups were matched by sex, age at surgery, and BMI. The daily habitual PA was measured over 4 consecutive days in daily living using a 3-axis accelerometer, gyroscope, and magnetometer. Both quantitative parameters (time standing, sitting, walking, number of steps, and sit-stand transfers) and qualitative parameters (walking cadence) were determined.Results - The AM was worn for a median 13 (11-16) hours per day. The median daily step count was 5,546 (2,274-9,966) for the HRA group and 4,583 (1,567-11,749) for the stemmed THA-group with 39 (21-74) versus 37 (24-62) daily sit-stand transfers respectively. The other PA parameters were also similar in both groups.Interpretation - We found similar median PA levels and also identical ranges. While short-term effects may exist, ageing and related behavioral adaptations or other effects seem to render the theoretical activity benefits from HRA irrelevant at longer follow-up.

Hip resurfacing generates a more physiological gait than total hip replacement: A case-control study

BACKGROUND

Restoration of the constitutional joint anatomy after hip replacement favours physiological peri-articular soft-tissue tension and kinematics, and is likely to be functionally beneficial. Hip resurfacing (HR) and conventional total hip replacement (THR) are two different options for replacing degenerated hips, and are likely to result in different anatomical reconstruction. We initiated this study to investigate the differences in gait performance between these two prosthetic options, and aimed to answer the following questions: (1) does HR result in better restoration of the frontal hip anatomical parameters, (2) and generate a more physiological gait compared to THR? (3) Does the quality of the anatomical restoration after THR influence gait performance?

HYPOTHESES

Our hypothesis was that a better anatomical restoration using HR versus THR would produce more physiological (symmetric) gait.

METHODS

We retrospectively reviewed 52 patients who had unilateral primary osteoarthritis successfully treated by replacement (40 THRs and 12 HRs). Hip anatomical parameters were measured on standing pelvic radiographs on both the prosthetic and the contralateral healthy hips. Patients undertook gait assessment under both normal and stress conditions at a mean follow-up of 14 months (7 to 16 months). Gait performances were compared between HR and THR, and the relationship between gait performances and quality of frontal anatomical restoration (estimated on radiograph) were assessed.

RESULTS

Compared to the native contralateral side, the HR procedure tended to decrease all independent anatomical radiographic parameters with the exception of the vertical centre of rotation offset, whilst the THR procedure tended to increase them; the difference between HR and THR was only statistically significant for femoral offset and global horizontal offset (increased after THR while reduced after HR). Only 50% of THR and 25% of HR procedures closely anatomically (±15%) recreated both global horizontal offset and global vertical offset. Under normal conditions (normal walking speed and flat ramp), the gait was fairly symmetric for both the HR and the THR patients with a symmetry index of 0.62% and 3.14% respectively. At high walking speed (stress conditions), the symmetry index degraded for both groups, but the gait remained more symmetric in the HR group (2.09%), compared to the THR group (5.74%); nevertheless, the difference remained not statistically significant (p=0.159). We were unable to detect any significant relationship between gait performances and radiographically measured hip frontal anatomical parameters.

DISCUSSION/CONCLUSIONS

HR procedure is more consistent than conventional THR in generating a more physiological gait under stress conditions. Radiographic estimation of the quality of the frontal anatomical hip restoration is of poor value to predict gait performances of THR patients.

LEVEL OF EVIDENCE

III - retrospective case-control study with prospective data collection.

Kinematic Gait Analysis After Primary Total Hip Replacement: A Systematic Review: Gait After Total Hip Replacement: A Systematic Review

Total hip replacement (THR) is a surgical procedure indicated for patients affected by severe hip osteoarthritis. Although this technique has proved to be effective in relieving pain and restoring function, gait limitations may persist following this procedure. The objective of this systematic review was to evaluate gait kinematics after THR and compare the results with those of the pre-operative state and with healthy control individuals. PubMed/MEDLINE, Embase, Web of Science, CENTRAL and Scopus databases were searched until December 2019. Methodological quality and internal validity score of each study were assessed using the PEDro and the Newcastle-Ottawa scales. In all, ten studies met our inclusion criteria. Following THR, statistically significant improvements were seen in dynamic hip and knee range of motion of both the affected and the contralateral limb, single-limb support time symmetry, step length, stride length, walking speed and gait pattern. However, deficits were observed in all the previous parameters, as well as in hip adduction angle in comparison with healthy subjects. In conclusion, gait patterns improve after THR in comparison with the pre-operative state, although there are deficits relative to healthy individuals.

A discrete element model to predict anatomy of the psoas muscle and path of the tendon: Design implications for total hip arthroplasty

BACKGROUND

The accurate estimation of a muscle's line of action is a fundamental requirement in computational modelling. We present a novel anatomical muscle wrapping technique and demonstrate its clinical use on the evaluation of the Psoas muscle mechanics in hip arthroplasty.

METHODS

A volume preserving, spring model to parameterize muscle anatomy changes during motion is presented. Validation was performed by a CT scan of a cadaver model in multiple positions. The predicted psoas musculotendinous path was compared with the actual imaging findings. In a second stage, psoas kinetics were compared between a conventional versus a resurfacing hip arthroplasty during gait.

FINDINGS

Anatomy prediction error was found to be 2.12 mm on average (SD 1.34 mm). When applied to psoas mechanics during walking, the muscle was found to wrap predominantly around the femoral head providing a biomechanically efficient and nearly constant moment arm for flexion during the entire gait cycle. However, this advantage was found to be lost in small diameter hip arthroplasty designs resulting in an important mechanical disadvantage. The moment arm for flexion, was on average 36% (SD 0.03%) lower in the small diameter conventional hip arthroplasty as compared to the large diameter head of the hip resurfacing and this difference was highly significant. (p < 0.001).

INTERPRETATION

Despite the shortcomings of an "in silico" and cadaveric study, our findings are in accordance with previous clinical and gait studies. Furthermore, the findings are strongly in favour of large diameter implant designs, warranting their further development and optimisation.

No difference in gait kinematics or kinetics between limbs in bilateral total hip replacement patients at long-term follow-up

BACKGROUND

Previous studies report that gait parameters of patients following total hip replacement improve from pre-operative levels, although in most cases do not reach those of normal subjects. However, studies are generally of unilateral total hip replacement patients at short-term follow-up. There have been no reports of 3D gait kinematics and kinetics in patients with bilateral total hip replacements at long-term follow-up. The aim of this study was to compare temporospatial parameters and 3D lower limb gait kinematics and kinetics at long-term follow-up between limbs and against controls for patients who have undergone staged bilateral total hip replacement.

METHODS

3D gait analysis was performed on 13 patients who had undergone bilateral total hip replacement, at an average follow-up of 10.1 (first hip) and 9.3 years (second hip), and a normal elderly control group comprising 10 subjects.

FINDINGS

Knee flexion/extension range of motion was marginally greater in Hip 2 (p = 0.049) compared to Hip 1 by 3.2°. There were no other significant differences in temporospatial parameters or a range of lower limb kinematics or kinetics between the first and second operated hip. Multiple gait parameters were significantly worse for both hips compared to age-matched normal individuals.

INTERPRETATION

Although symmetrical biomechanical recovery was achieved, significant gait deficiencies remain in both hips compared to normal controls. These deficits may provide targets for enhanced rehabilitation programs.

Step Length Asymmetry and Its Associations With Mechanical Energy Exchange, Function, and Fatigue After Total Hip Replacement

Abnormalities in gait remain after total hip replacement (THR). The purpose of this study was to evaluate step length asymmetry and its links to other aspects of gait and physical function after THR and to investigate links with mechanical energy exchange. The rationale is that step length asymmetry may influence gait efficiency, which could adversely influence fatigue and physical function. We evaluated 18 participants (6 males and 12 females) 1-5 years post-THR. Step length symmetry and mechanical energy exchange were assessed by instrumented gait analysis. Fatigue was assessed using a PROMIS Fatigue Short Form. We assessed physical function using a 6-minute walk test (6MWT). We used a one sample T test to determine whether the symmetry index (SI) was significantly different from 0 and Pearson's correlations to explore associations among the variables. The step length SI was statistically significantly different from zero (p=0.01). A more symmetric step length was associated with better 6MWT (R=-0.57, p=0.03). Higher (better) mechanical energy exchange was associated with more fatigue (R=0.50, p=0.04). Mechanical energy exchange was not associated with step length SI or 6MWT. Better 6MWT was associated with less fatigue (R=-0.61, P=0.01). This suggests that the association between step length symmetry and function is not directly governed by its effect on the energy exchange. Additionally, after a relatively long period of postsurgery, participants may have adapted their gait by increasing mechanical energy exchange to minimize fatigue. Statement of Clinical Significance: A gait retraining intervention targeting step length symmetry could improve function without adversely affecting walking energetics in THR patients. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1563-1570, 2019.

Gait analysis related to functional outcome in patients operated for ankle fractures

Ankle fractures are among the most common lower limb fractures. Associations between postoperative radiographic results and clinical outcome have been found, but less is known about the relevant ankle biomechanics. This study analyzed ankle kinematics, radiographic findings, and patient-reported outcome measures (PROM) in patients treated for ankle fractures. The hypothesis was that patients after ankle fracture surgery had less flexion/extension in the ankle compared to healthy subjects and that fracture severity had significant influence on kinematics and patient satisfaction. Thirty-three patients (n = 33 feet) operated for ankle fractures were recruited. Ankle kinematics were analyzed using the Oxford Foot model, and results were compared with an age-matched healthy control group (11 patients, 20 feet). In addition, patients were divided by fracture (severity) classification and kinematic results were correlated with PROM and radiographic findings. Patients treated for ankle fracture showed lower walking speed (p < 0.001) when asked to walk in preferred normal speed. When compared at equal speed, significantly less range of motion (ROM) between the hindfoot and tibia in the sagittal plane (flexion/extension) during loading and push-off phases (p = 0.003 and p < 0.001) was found in patients after ankle fractures compared to healthy subjects. Lowest ROM and poorest PROM results were found for patients with trimalleolar ankle fractures. There was a significant correlation between ROM (flexion/extension) during the push-off phase and SF-36 physical functioning (r²  = 0.403, p = 0.027) and SF-36 general health (r²  = 0.473, p = 0.008). Fracture severity was significantly correlated with flexion/extension ROM in the ankle during both loading and push-off phases (r²  = -0.382, p = 0.005, and r²  = -0.568, p < 0.001) and was also significantly correlated with PROM. This study found that patients with ankle fractures had significantly altered ankle kinematics compared to healthy subjects. The poorest results were found among patients with trimalleolar fractures. Weak to strong significant correlations were found between fracture severity, ankle kinematics, and PROM. © 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 37:1658-1666, 2019.

Superior migration of the femoral head in patients with severe hip osteoarthritis influences the gait patterns of the coronal plane

INTRODUCTION

Patients with hip osteoarthritis (OA) show abnormal movement patterns, including the leaning of the trunk toward the affected limb (Duchenne limp). Patients with severe OA, especially those with OA due to hip dysplasia, show a lateral pelvic drop (Trendelenburg sign).

AIM

The aim of this preoperative study is to investigate the relationship between superior migration of the arthritic femoral head, pain, and hip abductor muscle strength, and to clarify the relationship between the coronal plane gait patterns with pain and hip abductor muscle strength.

METHODS

The subjects of this study were 18 patients with unilateral hip OA secondary to dysplasia. A radiographic analysis was performed on standardised anteroposterior pelvis films. The abductor muscle strength of the OA hip joint was measured with a handheld dynamometer. The tilt angle of the pelvis and trunk lean angle during gait were obtained using a 3-dimensional motion analysis system. Visual analogue scale (VAS) of pain was obtained after trial.

RESULTS

The 2 lateral pelvic angle patterns at the mid-stance of the affected limb during gait were detected. 1 is a pattern that was pelvic rise, and the other was a contralateral pelvic drop. Subjects with pelvic drop showed more superior femoral migration than that with pelvic rise (r = 0.69 p < 0.01). VAS of pain correlate significantly with coronal trunk angle on mid-stance of affected limb during gait (r = 0.761, p < 0.01).

CONCLUSION

The pelvic drop Trendelenburg sign was influenced by superior migration of the femoral head, whereas the trunk lean Duchenne limp was found to be affected by pain.

Gait characteristics and functional outcomes during early follow-up are comparable in patients with calcaneal fractures treated by either the sinus tarsi or the extended lateral approach

BACKGROUND

To overcome the substantial functional loss after calcaneal fractures (CF), surgical treatment currently consists of two strategies, namely the commonly used extended lateral approach (ELA) and the less invasive sinus tarsi approach (STA). Despite the comparable anatomical restoration, the biomechanical and functional outcome of these strategies during early rehabilitation has not yet been investigated.

RESEARCH QUESTION

To evaluate changes in gait characteristics and functional development in patients with CF treated by either STA or ELA.

METHODS

A total of 56 patients with unilateral CF were included in this retrospective study. 26 patients were treated by ELA while 30 patients underwent surgery through the STA. Functional and biomechanical measurements were performed at follow-up periods of three and six months. Foot and ankle kinetics and kinematics were extracted using instrumented gait analysis with a multi segment foot model. Physical and mental components of the Short Form 36 (SF-36) and total scoring of the AOFAS hindfoot scale were used for functional evaluation. Statistical analysis was performed using Mann Whitney and Student's t-test. Effect sizes of group differences were calculated using Cohen's d.

RESULTS

Comparisons between ELA and STA showed no significant difference regarding the biomechanical and functional outcome. Within-group comparisons showed significant (p < 0.05) improvements from three to six month follow-up. Ankle joint and hindfoot kinematics showed increased mobility during walking of up to 34% and 26%, respectively. Maximum ankle joint moment also improved by up to 34% while vertical ground reaction force increased by 8%. Functional outcome only revealed significant changes in the physical component of SF-36.

SIGNIFICANCE

ELA and STA treatments revealed comparable functional improvements in patients with unilateral intraarticular calcaneal fractures during early rehabilitation. The less invasive STA provides adequate restoration of dynamic foot function and could serve as a viable alternative to the commonly used ELA.

Validation of inertial measurement units with optical tracking system in patients operated with Total hip arthroplasty

Background

Patient reported outcome measurement (PROMs) will not capture in detail the functional joint motion before and after total hip arthroplasty (THA). Therefore, methods more specifically aimed to analyse joint movements may be of interest. An analysis method that addresses these issues should be readily accessible and easy to use especially if applied to large groups of patients, who you want to study both before and after a surgical intervention such as THA. Our aim was to evaluate the accuracy of inertial measurement units (IMU) by comparison with an optical tracking system (OTS) to record pelvic tilt, hip and knee flexion in patients who had undergone THA.

Methods

49 subjects, 25 males 24 females, mean age of 73 years (range 51–80) with THA participated. All patients were measured with a portable IMU system, with sensors attached lateral to the pelvis, the thigh and the lower leg. For validation, a 12-camera motion capture system was used to determine the positions of 15 skin markers (Oqus 4, Qualisys AB, Sweden). Comparison of sagittal pelvic rotations, and hip and knee flexion-extension motions measured with the two systems was performed. The mean values of the IMU’s on the left and right sides were compared with OTS data.

Results

The comparison between the two gait analysis methods showed no significant difference for mean pelvic tilt range (4.9–5.4 degrees) or mean knee flexion range (54.4–55.1 degrees) on either side (p > 0.7). The IMU system did however record slightly less hip flexion on both sides (36.7–37.7 degrees for the OTS compared to 34.0–34.4 degrees for the IMU, p < 0.001).

Conclusions

We found that inertial measurement units can produce valid kinematic data of pelvis- and knee flexion-extension range. Slightly less hip flexion was however recorded with the inertial measurement units which may be due to the difference in the modelling of the pelvis, soft tissue artefacts, and malalignment between the two methods or misplacement of the inertial measurement units.

Trial registration

The study has ethical approval from the ethical committee “Regionala etikprövningsnämnden i Göteborg” (Dnr: 611–15, 2015-08-27) and all study participants have submitted written approval for participation in the study.

Gait and functionality following unilateral and bilateral hip replacement

Abstract Introduction: Total Hip Replacement (THR) is a surgical procedure used to minimize symptoms generated by orthopedic pathologies, such as osteoarthritis. It is emphasized that there is no agreement if gait parameters are restored after surgery. Objective: To compare gait space-time and functionality between individuals submitted to unilateral or bilateral THR in relation to healthy controls. Method: A cross-sectional study was conducted with 23 subjects, eight submitted to Bilateral THR (BG), eight submitted to Unilateral THR (UG) and seven healthy individuals (CG). For the gait analysis, the 10-meter walk test was used, with the subjects walking in their Habitual (HS) and Maximal (MS) gait Speeds. Variables of interest included average speed, number of steps, test duration, cadence and Inter-Stride Time Variability (ISTV). Functionality was assessed by the Harris Hip Score and the WOMAC questionnaire. Comparisons were made between the three groups. Results: At the HS condition, the average gait speed was significantly lower in the BG compared to the CG. Similarly, during the MS condition, the BG showed a lower gait speed compared to the CG. During MS gait, the BG performed significantly worse regarding ISTV compared to both the UG, and the CG. The functionality results showed that both the BG and UG scored significantly worse than the CG. Conclusion: Hip functionality and gait mechanics are impaired even after several years of surgery in subjects submitted to THR.

Gait analysis and functional outcome in patients after Lisfranc injury treatment

INTRODUCTION

Lisfranc injuries involve any bony or ligamentous disruption of the tarsometatarsal joint. Outcome results after treatment are mainly evaluated using patient-reported outcome measures (PROM), physical examination and radiographic findings. Less is known about the kinematics during gait.

METHODS

Nineteen patients (19 feet) treated for Lisfranc injury were recruited. Patients with conservative treatment and surgical treatment consisting of open reduction and internal fixation (ORIF) or primary arthrodesis were included. PROM, radiographic findings and gait analysis using the Oxford Foot Model (OFM) were analysed. Results were compared with twenty-one healthy subjects (31 feet). Multivariable logistic regression was used to determine factors influencing outcome.

RESULTS

Patients treated for Lisfranc injury had a significantly lower walking speed than healthy subjects (P<0.001). There was a significant difference between the two groups regarding the range of motion (ROM) in the sagittal plane (flexion-extension) in the midfoot during the push-off phase (p<0.001). The ROM in the sagittal plane was significantly correlated with the AOFAS midfoot score (r²=0.56, p=0.012), FADI (r²=0.47, p=0.043) and the SF-36-physical impairment score (r²=0.60, p=0.007) but not with radiographic parameters for quality of reduction. In a multivariable analysis, the best explanatory factors were ROM in the sagittal plane during the push-off phase (β=0.707, p=0.001), stability (β=0.423, p=0.028) and BMI (β=-0.727 p=<0.001). This prediction model explained 87% of patient satisfaction.

CONCLUSIONS

This study showed that patients treated for Lisfranc injury had significantly lower walking speed and significantly lower flexion/extension in the midfoot than healthy subjects. The ROM in these patients was significantly correlated with PROM, but not with radiographic quality of reduction. Most important satisfaction predictors were BMI, ROM in the sagittal plane during the push-off phase and fracture stability.

Biomechanical changes and recovery of gait function after total hip arthroplasty for osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To determine the change in walking gait biomechanics after total hip arthroplasty (THA) for osteoarthritis (OA) compared to the pre-operative gait status, and to compare the recovery of gait following THA with healthy individuals.

METHODS

Systematic review with meta-analysis of studies investigating changes in gait biomechanics after THA compared to (1) preoperative levels and (2) healthy individuals. Data were pooled at commonly reported time points and standardised mean differences (SMDs) were calculated in meta-analyses for spatiotemporal, kinematic and kinetic parameters.

RESULTS

Seventy-four studies with a total of 2,477 patients were included. At 6 weeks postoperative, increases were evident for walking speed (SMD: 0.32, 95% confidence intervals (CI) 0.14, 0.50), stride length (SMD: 0.40, 95% CI 0.19, 0.61), step length (SMD: 0.41, 95% CI 0.23, 0.59), and transverse plane hip range of motion (ROM) (SMD: 0.36, 95% CI 0.05, 0.67) compared to pre-operative gait. Sagittal, coronal and transverse hip ROM was significantly increased at 3 months (SMDs: 0.50 to 1.07). At 12 months postoperative, patients demonstrated deficits compared with healthy individuals for walking speed (SMD: -0.59, 95% CI -1.08 to -0.11), stride length (SMD: -1.27, 95% CI -1.63, -0.91), single limb support time (SMD: -0.82, 95% CI -1.23, -0.41) and sagittal plane hip ROM (SMD: -1.16, 95% CI -1.83, -0.49). Risk of bias scores ranged from seven to 24 out of 26.

CONCLUSIONS

Following THA for OA, early improvements were demonstrated for spatiotemporal and kinematic gait patterns compared to the pre-operative levels. Deficits were still observed in THA patients compared to healthy individuals at 12 months.

The Assessment of Static Balance in Patients after Total Hip Replacement in the Period of 2-3 Years after Surgery

Introduction

The aim of this study was to assess static balance of patients after Total Hip Replacement (THR) compared with the age-matched, asymptomatic control group, considering the subject's gender and the time since the surgery.

Materials and Methods

The Total Hip Replacement (THR) group consisted of 55 subjects (mean age: 56.3 ± 8.7 years) and the control group consisted of 48 subjects (mean age: 58 ± 6.2 years). For the assessment of static balance, a stabilometric force platform was used. All subjects performed two 30-second trials in the double-leg stance position with eyes opened and closed. In the study group, the stabilometric assessment was performed once within the period of 24 to 36 months after the surgery.

Results

Subjects from the study group had significantly increased mediolateral COP velocity in the test with eyes opened, as well as the values of most of the COP parameters (excluding COP path area) in the test with eyes closed, compared to the control group. Higher values of the selected COP parameters were observed in the male subjects from the study group.

Conclusion

In contrast to a number of papers, our study revealed some deficits in static balance in patients after THR up to 2-3 years after surgery.

Hip movement pathomechanics of patients with hip osteoarthritis aim at reducing hip joint loading on the osteoarthritic side

This study aims at defining gait pathomechanics in patients with hip osteoarthritis (OA) and their effect on hip joint loading by combining analyses of hip kinematics, kinetics and contact forces during gait. Twenty patients with hip OA and 17 healthy volunteers matched for age and BMI performed three-dimensional gait analysis. Hip OA level was evaluated based on plane radiographs using the Tönnis classification. Hip joint kinematics, kinetics as well as hip contact forces were calculated. Waveforms were time normalized and compared between groups using statistical parametric mapping analysis. Patients walked with reduced hip adduction angle and reduced hip abduction and external rotation moments. The work generated by the hip abductors during the stance phase of gait was largely decreased. These changes resulted in a decrease and a more vertical and anterior orientation of the hip contact forces compared to healthy controls. This study documents alterations in hip kinematics and kinetics resulting in decreased hip loading in patients with hip OA. The results suggested that patients altered their gait to increase medio-lateral stability, thereby decreasing demand on the hip abductors. These findings support discharge of abductor muscles that may bear clinical relevance of tailored rehabilitation targeting hip abductor muscles strengthening and gait retraining.

Vertical ground reaction forces in patients after calcaneal trauma surgery

INTRODUCTION

Vertical ground reaction forces (VGRFs) are altered in patients after foot trauma. It is not known if this correlates with ankle kinematics. The aim of this study was to analyze VGRFs in patients after calcaneal trauma and correlate them to patient-reported outcome measures (PROMs), radiographic findings and kinematic analysis, using a multi-segment foot model. In addition, we determined the predictive value of VGRFs to identify patients with altered foot kinematics.

METHODS

Thirteen patients (13 feet) with displaced intra-articular calcaneal fractures, were included an average of two years after trauma surgery. PROMs, radiographic findings on postoperative computed tomography scans, gait analysis using the Oxford foot model and VGRFs were analysed during gait. Results were compared with those of 11 healthy subjects (20 feet). Speed was equal in both groups, with healthy subjects walking at self-selected slow speed (0.94±0.18m/s) and patients after surgery walking at self-selected normal speed (0.94±0.29m/s). ROC curves were used to determine the predictive value.

RESULTS

Patients after calcaneal surgery showed a lower minimum force during midstance (p=0.004) and a lower maximum force during toe-off (p=0.011). This parameter correlated significantly with the range of motion in the sagittal plane during the push-off phase (r 0.523, p=0.002), as well as with PROMs and with postoperative residual step-off (r 0.423, p=0.016). Combining these two parameters yielded a cut-off value of 193% (p<0.001), area under the curve 0.93 (95%confidence interval 0.84-1.00).

CONCLUSION

Patients after calcaneal fracture showed lower minimum force during midstance and lower maximum force during toe-off compared to healthy subjects. This lower maximum force during push-off correlated significantly with PROMs, range of motion in the sagittal plane during push-off and radiographic postoperative residual step-off in the posterior facet of the calcaneal bone. VGRFs are a valuable screening tool for identifying patients with altered gait patterns.

High-impact sport after hip resurfacing: The Ironman triathlon

BACKGROUND

Returning to high-impact sport is an increasingly frequent functional demand following hip replacement. The literature, however, is sparse on the subject and nonexistent regarding triathlon. We therefore conducted a retrospective study of hip resurfacing in triathlon players, to determine: (1) whether it is possible to return to this kind of sport; (2) if so, whether it is possible to return to the same level; and (3) how a resurfaced hip behaves under these conditions.

HYPOTHESIS

Hip resurfacing allows return to competition level in long-distance triathlon.

MATERIAL AND METHODS

A single-center single-operator retrospective study included patients undergoing hip resurfacing with the Conserve Plus implant inserted through a posterolateral approach, who had ceased long-distance triathlon practice due to osteoarthritis of the hip. Fifty-one of the 1688 patients undergoing resurfacing during the inclusion period were long-distance triathlon players.

RESULTS

The series comprised 48 patients: 51 implants; 43 male, 5 female; mean age, 44.8 years (range, 28.2-58.9 years). At a mean 4.7 years' follow-up (range, 2.2-7.6 years), all clinical scores showed significant improvement; Merle d'Aubigné and Harris scores rose respectively from 12.3 (5-16) and 42 (37-56) preoperatively to 17.5 (13-18) and 93.2 (73-100) (P<0.001). There were no cases of dislocation or implant revision. Forty-five patients returned to sport (94%). Rates of return to swimming, cycling and running were respectively 38/48 (79%), 41/48 (85%) and 33/48 (69%). Preoperatively, all patients had taken part in at least 1 competition: 29 with distance=70.3km and 19 with distance=140.6km. At follow-up, 28 patients had taken part in an Ironman competition: 21 with distance=70.3km and 7 with distance=140.6km. Mean competition performance did not differ between pre and postoperative periods.

DISCUSSION

Return-to-sport rates were good following hip resurfacing. Non-impact sports (swimming, cycling) predominated postoperatively, whereas the rate of impact sport (running) diminished. Return to competition-level sport (extreme triathlon) was possible for 28/48 patients (58%). Implant survival seemed unaffected by this high-impact sports activity at a mean 4.7 years' follow-up.

LEVEL OF EVIDENCE

IV, retrospective, non-controlled.

Gait Kinematic Deviations in Patients With Developmental Dysplasia of the Hip Treated With Total Hip Arthroplasty

Comprehensive gait analysis of patients with Crowe type II and III developmental dysplasia of the hip (DDH) after successful total hip arthroplasty (THA) is lacking in the literature. This study evaluated gait function in joint kinematics after unilateral and bilateral THA in patients with DDH. In addition, the effect of high cup position on gait function was investigated. A total of 16 unilateral and 15 bilateral cementless THA patients due to DDH and 10 healthy participants comprised the study population. Levels of superior displacement of the acetabular cup and leg-length discrepancy after THA were measured. Three-dimensional gait analysis for patients who underwent THA was performed at least 1 year postoperatively. Range of motion (ROM), particularly sagittal (flexion/extension) and frontal (adduction/abduction) hip joint ROM, was significantly lower in both the unilateral and bilateral groups than in healthy participants. Sagittal (flexion/extension) hip ROM in patients with DDH was greater in the unilateral group than in the bilateral group. A significant influence of high acetabular cup position on hip joint kinematics was not observed in the unilateral subgroups (mean level of cup superior displacement was 11.8 mm). In contrast, a significant influence of high acetabular cup position on hip joint kinematics was observed in the bilateral subgroups (mean level of cup superior displacement was 21.3 mm). The functional symmetry and cup superior displacement within 12 mm in patients with DDH after unilateral THA contributed to the restoration of normal hip biomechanics. [Orthopedics. 2017; 40(3):e425-e431.].

Gait kinetics of total hip replacement patients-A large scale, long-term follow-up study

BACKGROUND

It is not known if lower limb gait kinetics of total hip replacement (THR) patients reach normal levels at long term follow-up post-operatively.

METHODS

Three-dimensional gait analysis was performed on 134 THR patients with identical implants 10-years post-operatively. Lower limb moments and powers were compared between different age strata (54-64 years, 65-69 years, 70-74 years, 75-79 years and over 80 years) and a normal elderly control group.

RESULTS

Hip extensor moment and hip power generation were significantly reduced in all age groups compared to normal. External hip rotation moment was significantly reduced in all age groups, apart from the youngest group, compared to normal. However, in contrast to previous short term follow-up studies there was no significant difference in hip abduction moment between any of the age groups and the normal group.

CONCLUSION

This large cohort study shows that, at long term follow-up following THR, some hip joint kinetics (hip extensor and external rotation moments and hip power generation) do not reach normal levels, but that peak abduction moment is preserved. THR patients recovery could potentially benefit from intensive rehabilitation focusing on hip extension and external rotation in the post-operative, and perhaps preoperative, period.

Factors associated with restricted hip extension during gait in women after total hip arthroplasty

PURPOSE

A decreased peak hip extension angle in the late stance phase is a major gait abnormality in patients with THA. The purpose of this study was to determine the relationship between peak hip extension angle during gait and functional impairments such as muscle weakness and the limitation in joint range of motion and to identify the clinical factors influencing peak hip extension angle during gait.

METHODS

67 female volunteers with THA were examined. Biomechanical gait analysis was performed to measure peak hip extension angle during gait. Maximal isometric strength of the hip and knee, passive hip extension range of motion, leg length discrepancy, and hip pain were assessed.

RESULTS

Peak hip extension angle during gait significantly correlated with passive hip extension range of motion (r = 0.259), hip pain (r = -0.264), isometric strengths of the hip musculature (r = 0.278-0.491), and knee extensor (r = 0.386). Stepwise multiple regression analysis revealed that hip abductor torque (β = 0.355, P = 0.001), hip pain (β = -0.353, P = 0.001), and passive hip extension range of motion (β = 0.258, P = 0.011) were significant contributors to peak hip extension angle during gait (R2 = 0.408).

CONCLUSIONS

Our findings suggest that THA rehabilitation aimed at improving gait ability should focus on strengthening the hip abductors, controlling hip pain and increasing range of motion of hip extension.

Is there any range-of-motion advantage to using bearings larger than 36mm in primary hip arthroplasty: A case-control study comparing 36-mm and large-diameter heads

BACKGROUND

Large-diameter (>36mm) total hip arthroplasty (THA) has developed rapidly since the advent of ceramic-on-ceramic (CoC) bearings and highly cross-linked polyethylene. Theoretically, the increase in diameter reduces the risk of instability, although the advantage of calibers beyond 36mm has not been demonstrated in terms of range-of-motion recovery. We conducted a comparative study with a single prosthesis model to determine whether increasing the caliber beyond 36mm provides: (1) better recovery of range-of-motion, (2) a higher functional score, and (3) reduction of the dislocation rate.

HYPOTHESIS

Increasing the range-of-motion by increasing the caliber beyond 36mm provides better range-of-motion.

MATERIAL AND METHODS

We analyzed two consecutive, single-operator cementless THA series performed via the mini posterior approach, which differed only in the bearing system (51 metal-on-metal [MoM] with a mean caliber of 45mm±3.3 [range, 40-54] and 61 CoC with a 36-mm caliber). Both series were comparable preoperatively in terms of age, diagnosis, functional scores, preoperative range-of-motion, body mass index, UCLA activity level, and Charnley score. We compared the joint range of movement at follow-up and the gains in range of movement, onset of dislocation, and functional scores (Oxford, Postel-Merle d'Aubigné [PMA]).

RESULTS

The mean overall joint range-of-motion was 254°±39° (range, 150-310°) for an 81°±44° (range, -50 to 180°) gain in the MoM group and 256°±23° (range, 200-280°) for an 84°±40° (range, 0-160°) gain in the CoC group (NS). The MoM group presented the following results: Oxford=13.71±3.66 (range, 12-33) for a gain of 24.82 points±7.9 (range, -1 to 40), PMA=17.75±1.06 (range, 11-18) for a gain of 7.78 points±4.01 (range, 2-15). The CoC group had: Oxford=14.98±4.42 (range, 12-36) for a gain of 24.75 points±6.55 (range, 12-40), PMA 17.66±0.7 (range, 14-18) for a gain of 8 points±3.77 (range, 1-15). None of the gains and scores at follow-up differed significantly between the two groups. No episode of dislocation was identified.

DISCUSSION

The current trend of increasing femoral head diameters beyond 36mm to improve the gains in joint range-of-motion and function is not warranted. The potential side effects of increasing the caliber call for even greater caution in the use of large-diameter heads because our hypothesis has not been confirmed.

LEVEL OF EVIDENCE

Case-control study, level III.

Does surgical approach or prosthesis type affect hip joint loading one year after surgery?

Several approaches may be used for hip replacement surgery either in combination with conventional total hip arthroplasty (THA) or resurfacing hip arthroplasty (RHA). This study investigates the differences in hip loading during gait one year or more after surgery in three cohorts presenting different surgical procedures, more specific RHA placed using the direct lateral (RHA-DLA, n=8) and posterolateral (RHA-PLA, n=14) approach as well as THA placed using the direct anterior (THA-DAA, n=12) approach. For the DAA and control subjects, hip loading was also evaluated during stair ascent and descent to evaluate whether these motions can better discriminate between patients and controls compared to gait. Musculoskeletal modelling in OpenSim was used to calculate in vivo joint loading. Results showed that for all operated patients, regardless the surgical procedure, hip loading was decreased compared to control subjects, while no differences were found between patient groups. This indicates that THA via DAA results in similar hip loading as a RHA via DLA or PLA. Stair climbing did not result in more distinct differences in hip contact force magnitude between patients and controls, although differences in orientation were more distinct. However, patients after hip surgery did adjust their motion pattern to decrease the magnitude of loading on the hip joint compared to control subjects.

Gait Analysis and Functional Outcome After Calcaneal Fracture

BACKGROUND

Calcaneal fractures are associated with substantial morbidity and socioeconomic impact, frequently leading to limited functional outcome and high economic costs. The Oxford foot model (OFM) has been reported as a valid addition to the biomechanical examination of the foot. The aim of our study was to analyze the gait of patients after operative repair of a calcaneal fracture in relation to functional outcome and radiographic findings.

METHODS

Thirteen patients with a calcaneal fracture underwent gait analysis with OFM at a minimum of six months after open surgery. Intersegmental range of motion was measured during gait. Results were compared with those of healthy subjects and those of patients who had undergone subtalar arthrodesis. Patient-reported questionnaires and radiographic images were also evaluated.

RESULTS

The range of motion between the hindfoot and the tibia in the push-off phase in the transverse plane was significantly correlated with the clinical outcome as reported by patients based on the Foot and Ankle Disability Index (FADI) (r(2) = 0.51; p < 0.001) and the Short Form (SF)-36 physical component summary score (r(2) = 0.52; p < 0.001). We found a significant correlation between the step-off in the subtalar joint as measured on postoperative computed tomography (CT) and range of motion (r(2) = -0.74; p = 0.004). The step-off was also correlated with the patient-reported outcome questionnaire FADI (r(2) = -0.76; p = 0.003) and the SF-36 physical component summary score (r(2) = -0.78; p = 0.002).

CONCLUSIONS

This study demonstrated that the subtalar joint range of motion of patients after a calcaneal fracture was related both to the quality of the reduction of the subtalar joint as evaluated on postoperative CT scans and patient-reported functional outcome.

Total hip replacement and surface replacement for the treatment of pain and disability resulting from end-stage arthritis of the hip (review of technology appraisal guidance 2 and 44): systematic review and economic evaluation

BACKGROUND

Total hip replacement (THR) involves the replacement of a damaged hip joint with an artificial hip prosthesis. Resurfacing arthroplasty (RS) involves replacement of the joint surface of the femoral head with a metal surface covering.

OBJECTIVES

To undertake clinical effectiveness and cost-effectiveness analysis of different types of THR and RS for the treatment of pain and disability in people with end-stage arthritis of the hip, in particular to compare the clinical effectiveness and cost-effectiveness of (1) different types of primary THR and RS for people in whom both procedures are suitable and (2) different types of primary THR for people who are not suitable for hip RS.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, The Cochrane Library, Current Controlled Trials and UK Clinical Research Network (UKCRN) Portfolio Database were searched in December 2012, with searches limited to publications from 2008 and sample sizes of ≥ 100 participants. Reference lists and websites of manufacturers and professional organisations were also screened.

REVIEW METHODS

Systematic reviews of the literature were undertaken to appraise the clinical effectiveness and cost-effectiveness of different types of THR and RS for people with end-stage arthritis of the hip. Included randomised controlled trials (RCTs) and systematic reviews were data extracted and risk of bias and methodological quality were independently assessed by two reviewers using the Cochrane Collaboration risk of bias tool and the Assessment of Multiple Systematic Reviews (AMSTAR) tool. A Markov multistate model was developed for the economic evaluation of the technologies. Sensitivity analyses stratified by sex and controlled for age were carried out to assess the robustness of the results.

RESULTS

A total of 2469 records were screened of which 37 were included, representing 16 RCTs and eight systematic reviews. The mean post-THR Harris Hip Score measured at different follow-up times (from 6 months to 10 years) did not differ between THR groups, including between cross-linked polyethylene and traditional polyethylene cup liners (pooled mean difference 2.29, 95% confidence interval -0.88 to 5.45). Five systematic reviews reported evidence on different types of THR (cemented vs. cementless cup fixation and implant articulation materials) but these reviews were inconclusive. Eleven cost-effectiveness studies were included; four provided relevant cost and utility data for the model. Thirty registry studies were included, with no studies reporting better implant survival for RS than for all types of THR. For all analyses, mean costs for RS were higher than those for THR and mean quality-adjusted life-years (QALYs) were lower. The incremental cost-effectiveness ratio for RS was dominated by THR, that is, THR was cheaper and more effective than RS (for a lifetime horizon in the base-case analysis, the incremental cost of RS was £11,284 and the incremental QALYs were -0.0879). For all age and sex groups RS remained clearly dominated by THR. Cost-effectiveness acceptability curves showed that, for all patients, THR was almost 100% cost-effective at any willingness-to-pay level. There were age and sex differences in the populations with different types of THR and variations in revision rates (from 1.6% to 3.5% at 9 years). For the base-case analysis, for all age and sex groups and a lifetime horizon, mean costs for category E (cemented components with a polyethylene-on-ceramic articulation) were slightly lower and mean QALYs for category E were slightly higher than those for all other THR categories in both deterministic and probabilistic analyses. Hence, category E dominated the other four categories. Sensitivity analysis using an age- and sex-adjusted log-normal model demonstrated that, over a lifetime horizon and at a willingness-to-pay threshold of £20,000 per QALY, categories A and E were equally likely (50%) to be cost-effective.

LIMITATIONS

A large proportion of the included studies were inconclusive because of poor reporting, missing data, inconsistent results and/or great uncertainty in the treatment effect estimates. This warrants cautious interpretation of the findings. The evidence on complications was scarce, which may be because of the absence or rarity of these events or because of under-reporting. The poor reporting meant that it was not possible to explore contextual factors that might have influenced study results and also reduced the applicability of the findings to routine clinical practice in the UK. The scope of the review was limited to evidence published in English in 2008 or later, which could be interpreted as a weakness; however, systematic reviews would provide summary evidence for studies published before 2008.

CONCLUSIONS

Compared with THR, revision rates for RS were higher, mean costs for RS were higher and mean QALYs gained were lower; RS was dominated by THR. Similar results were obtained in the deterministic and probabilistic analyses and for all age and sex groups THR was almost 100% cost-effective at any willingness-to-pay level. Revision rates for all types of THR were low. Category A THR (cemented components with a polyethylene-on-metal articulation) was more cost-effective for older age groups. However, across all age-sex groups combined, the mean cost for category E THR (cemented components with a polyethylene-on-ceramic articulation) was slightly lower and the mean QALYs gained were slightly higher. Category E therefore dominated the other four categories. Certain types of THR appeared to confer some benefit, including larger femoral head sizes, use of a cemented cup, use of a cross-linked polyethylene cup liner and a ceramic-on-ceramic as opposed to a metal-on-polyethylene articulation. Further RCTs with long-term follow-up are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013003924.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Biomechanical gait features associated with hip osteoarthritis: Towards a better definition of clinical hallmarks

Critical appraisal of the literature highlights that the discriminative power of gait-related features in patients with hip osteoarthritis (OA) has not been fully explored. We aimed to reduce the number of gait-related features and define the most discriminative ones comparing the three-dimensional gait analysis of 20 patients with hip osteoarthritis (OA) with those of 17 healthy peers. First, principal component analysis was used to reduce the high-dimensional gait data into a reduced set of interpretable variables for further analysis, including tests for group differences. These differences were indicative for the selection of the top 10 variables to be included into linear discriminant analysis models (LDA). Our findings demonstrated the successful data reduction of hip osteoarthritic-related gait features with a high discriminatory power. The combination of the top variables into LDA models clearly separated groups, with a maximum misclassification error rate of 19%, estimated by cross-validation. Decreased hip/knee extension, hip flexion and internal rotation moment were gait features with the highest discriminatory power. This study listed the most clinically relevant gait features characteristics of hip OA. Moreover, it will help clinicians and physiotherapists understand the movement pathomechanics related to hip OA useful in the management and design of rehabilitation intervention.

Gait Characteristics, Symptoms, and Function in Persons With Hip Osteoarthritis: A Longitudinal Study With 6 to 7 Years of Follow-up

STUDY DESIGN

Longitudinal laboratory study.

OBJECTIVES

(1) To compare gait characteristics between individuals with early-stage hip osteoarthritis who underwent total hip replacement (THR) and those who did not undergo THR, and (2) to evaluate whether gait characteristics, function, and symptoms declined among individuals who did not undergo THR during a 6- to 7-year follow-up.

BACKGROUND

The natural history of symptoms, function, and gait changes secondary to hip osteoarthritis, including potential differences at an early stage of disease, is unknown.

METHODS

Forty-three individuals (mean age, 58.9 years) with radiographic and symptomatic hip osteoarthritis participated. Outcome measures included 3-D gait analysis; self-reported pain, stiffness, and function; hip range of motion; and the six-minute walk test. Baseline comparisons between individuals who later underwent THR and those who did not undergo THR were made using independent t tests or Mann-Whitney U tests. Comparisons of baseline measures and 6- to 7-year follow-up for the nonoperated individuals were conducted with paired-samples t tests or Wilcoxon signed-rank tests (P<.05).

RESULTS

Twelve (27.9%) of the 43 individuals initially evaluated had not undergone THR at the 6- to 7-year follow-up. At baseline, these individuals had larger sagittal plane hip and knee joint excursions, larger joint space width, lower body mass index, and superior self-reported function compared with the individuals who later underwent THR. At the 6- to 7-year follow-up, the individuals who did not undergo THR exhibited no decline in gait characteristics, minimum joint space, or overall function. Furthermore, their self-reported pain had significantly decreased (P = .024).

CONCLUSION

Individuals who did not undergo THR during a 6- to 7-year follow-up period did not exhibit a decline in gait, function, or symptoms compared to those who underwent THR. These findings are suggestive of a phenotype of hip osteoarthritis with a very slow disease progression, particularly in regard to pain.

LEVEL OF EVIDENCE

Prognosis, level 1b.

The use of the Gait Deviation Index for the evaluation of participants following total hip arthroplasty: An explorative randomized trial

INTRODUCTION

In this paper, the Gait Deviation Index (GDI) was used as a convenient method to evaluate pre-to-postoperative gait pattern changes after total hip arthroplasty and identify factors which might be predictive of outcome.

DESIGN

Three-dimensional gait data from a randomized clinical trial was used to determine changes in gait quality in participants walking at self-selected speed. Upon completion of the first assessment, the participants were randomly assigned to either resurfacing hip arthroplasty or conventional hip arthroplasty. The outcome was changes in overall gait 'quality' measured with GDI during the 6-month post-surgery follow-up period.

RESULTS

38 participants with severe unilateral primary hip osteoarthritis took part in the trial. We found no difference in change scores between the two treatment groups; 1.9 [95%CI: -0.3 to 4.0] or between change scores for the non-operated and the operated limbs; 0.3 [95%CI: -2.3 to 1.7]. However, the score for the two groups (pooled data) improved after surgery by 4.4 [95%CI: 1.8-7.0]. The single level regression analysis identified the preoperative GDI score as a strong predictor of outcome (p<0.001).

CONCLUSION

Six months after surgery, there was no additional effect of resurfacing hip arthroplasty on GDI scores compared with conventional hip arthroplasty. Participants with the most pathological preoperative gait pattern improved the most. The GDI increased, which indicates an overall improvement in gait pathology after surgery.

TRIAL REGISTRATION

NCT01229293.

Gait and lower limb muscle strength in women after triple innominate osteotomy

Background

In adult patients with developmental hip dysplasia, a surgical procedure (triple innominate osteotomy) of the pelvic bone can be performed to rotate the acetabulum in the frontal plane, establishing better acetabular coverage. Although common clinical hip scores demonstrate significant improvements after surgery, they provide only overall information about function. The purpose of this study was to quantify the long-term outcome of triple innominate osteotomy in more detail using gait analyses and muscle strength measurements.

Methods

We performed gait analyses at self-selected walking speed as well as isometric hip and knee muscle strength tests in twelve women who had undergone a unilateral triple innominate osteotomy (age: 34 ± 12 y, time post surgery: 80 ± 18 m). We compared the results to reference values obtained from eight healthy peers (age: 33 ± 10 y).

Results

The patients exhibited slight asymmetries in step length (smaller steps) and stance time (longer stance) as well as lower hip abduction moments in the operated limb in early stance compared to the non-operated limb. However, there were no differences in gait compared to healthy controls, even though the patients showed reduced bilateral hip abduction strength compared to controls.

Conclusions

Our results indicate that the patients’ gait pattern had generally recovered very well, despite slight asymmetries in spatiotemporal parameters. Subtle deviations in hip abduction moments were observed during gait, whereas hip abduction strength was substantially reduced. Hence, the patients walked at a higher percentage of their maximal capacity. They may, therefore, be prone to fatigue and adopt compensatory gait strategies more quickly than healthy peers when walking long distances.

Femoral head diameter considerations for primary total hip arthroplasty

The configuration of total hip arthroplasty (THA) implants has constantly evolved since they were first introduced. One of the key components of THA design is the diameter of the prosthetic femoral head. It has been well established that the risk of dislocation is lower as the head diameter increases. But head diameter impacts other variables beyond joint stability: wear, cam-type impingement, range of motion, restoration of biomechanics, proprioception and groin pain. The introduction of highly cross-linked polyethylene and hard-on-hard bearings has allowed surgeons to implant large-diameter heads that almost completely eliminate the risk of dislocation. But as a result, cup liners have become thinner. With femoral head diameters up to 36 mm, the improvement in joint range of motion, delay in cam-type impingement and reduction in dislocation risk have been clearly demonstrated. Conversely, large-diameter heads do not provide any additional improvements. If an "ecologically sound" approach to hip replacement is embraced (e.g. keeping the native femoral head diameter), hip resurfacing with a metal-on-metal bearing must be carried out. The reliability of large-diameter femoral heads in the longer term is questionable. Large-diameter ceramic-on-ceramic bearings may be plagued by the same problems as metal-on-metal bearings: groin pain, squeaking, increased stiffness, irregular lubrication, acetabular loosening and notable friction at the Morse taper. These possibilities require us to be extra careful when using femoral heads with a diameter greater than 36 mm.

The effect of total hip and hip resurfacing arthroplasty on vertical ground reaction force and impulse symmetry during a sit-to-stand task

BACKGROUND

The aim of this study was to determine the influence of total hip arthroplasty and hip resurfacing arthroplasty on limb loading symmetry before, and after, hip reconstruction surgery during a sit-to-stand task.

METHODS

Fourteen patients were recruited that were about to receive either a total hip prosthesis (n=7) or a hip resurfacing prosthesis (n=7), as well as matched controls. Patients performed a sit-to-stand movement before, 3 months after, and 12 months after surgery. Peak vertical ground reaction force and impulse were measured for each leg, from which ground reaction force and impulse symmetry ratios were calculated.

FINDINGS

Before surgery, hip resurfacing patients showed a small asymmetry which was not different to normal for ground reaction force (0.88(0.28) vs. 1.00(0.11); p=0.311) or impulse (0.87(0.29) vs. 0.99(0.09); p=0.324) symmetry ratios. Total hip patients offloaded their affected hip by 30% in terms of impulse symmetry ratio (0.71(0.36) vs. 0.99(0.23); p=0.018). At 3 months following surgery asymmetries were seen that were different to normal in both hip resurfacing patients for ground reaction force (0.77(0.16); p=0.007), and total hip patients for ground reaction force (0.70(0.15); p=0.018) and impulse (0.72(0.16); p=0.011) symmetry ratios. By 12 months after surgery total hip patients regained a symmetrical loading pattern for both ground reaction force (0.95(0.06); p=0.676) and impulse (1.00(0.06); p=0.702) symmetry ratios. Hip resurfacing patients, however, performed the task by overloading their operated hip, with impulse symmetry ratio being larger than normal (1.16(0.16); p=0.035).

INTERPRETATION

Physiotherapists should appreciate the need for early recovery of limb loading symmetry as well as subsequent differences in the responses observed with different prostheses.

Gait and gait-related activities of daily living after total hip arthroplasty: a systematic review

BACKGROUND

Differences in the performance of gait and gait-related activities of daily living are known to persist after total hip arthroplasty compared to healthy controls, but the specific underlying deficits (spatiotemporal, kinematics and kinetics) are not completely understood. This review aimed to map the differences between patients and controls, and between the operated and non-operated limbs during various activities of daily living.

METHODS

A computerized search with broad search terms was performed in the MEDLINE database. Primary inclusion criteria were: primary osteoarthritis as indication, comparison with healthy controls or comparison between the operated and the non-operated limbs, and follow-up period at least six months after surgery.

FINDINGS

The literature search yielded 2177 citations, of which 35 articles were included. Compared to controls, reductions were identified in the operated hip in sagittal range of motion, peak extension, sagittal power generation, abduction moment and external rotation moment. During stair ascent, these reductions did not become more apparent, although deficits in hip kinetics in all three planes were found. Walking speed and step length were reduced compared to controls at longer-term follow-up, but not at short-term follow-up.

INTERPRETATION

The hip abduction moment deficit was present both in level walking and in stair ascent in total hip arthroplasty patients compared to controls. Reduced sagittal hip power generation and external rotation moment were also found, of which the clinical relevance remains to be established. Due to a low number of studies, many of the longer-term effects of THA on gait and gait-related ADL are not yet accurately known.

Gait parameters and muscle activation patterns at 3, 6 and 12 months after total hip arthroplasty

Gait analysis was performed on 20 patients with unilateral hip prosthesis (3, 6 and 12 months post-operatively) and 20 controls to investigate their gait characteristics and muscle activation patterns. One year after the intervention, patients still walked with a higher percentage of "atypical" cycles, a prolonged heel contact, a shortened flat foot contact, a reduced hip dynamic range of motion and abnormal timing in the muscle activation patterns of tibialis anterior, gastrocnemius lateralis, biceps femoris and gluteus medius, with respect to the control group. Although the gait velocity and the knee range of motion improved from 3 to 6 months post-surgery, the above mentioned parameters did not improve from 6 to 12 months. THA patients failed to obtain normal gait one year after surgery.

Metal-on-metal hip resurfacing compared with 28-mm diameter metal-on-metal total hip replacement: a randomised study with six to nine years' follow-up

A total of 219 hips in 192 patients aged between 18 and 65 years were randomised to 28-mm metal-on-metal uncemented total hip replacements (THRs, 107 hips) or hybrid hip resurfacing (HR, 112 hips). At a mean follow-up of eight years (6.6 to 9.3) there was no significant difference between the THR and HR groups regarding rate of revision (4.0% (4 of 99) vs 5.8% (6 of 104), p = 0.569) or re-operation rates without revision (5.1% (5 of 99) vs 2.9% (3 of 104), p = 0.428). In the THR group one recurrent dislocation, two late deep infections and one peri-prosthetic fracture required revision, whereas in the HR group five patients underwent revision for femoral head loosening and one for adverse reaction to metal debris. The mean University of California, Los Angeles activity scores were significantly higher in HR (7.5 (sd 1.7) vs 6.9 (sd 1.7), p = 0.035), but similar mean Western Ontario and McMaster Universities Osteoarthritis Index scores were obtained (5.8 (sd 9.5) in HR vs 5.1 (sd 8.9) in THR, p = 0.615) at the last follow-up. Osteolysis was found in 30 of 81 THR patients (37.4%), mostly in the proximal femur, compared with two of 83 HR patients (2.4%) (p < 0.001). At five years the mean metal ion levels were < 2.5 μg/l for cobalt and chromium in both groups; only titanium was significantly higher in the HR group (p = 0.001). Although revision rates and functional scores were similar in both groups at mid-term, long-term survival analysis is necessary to determine whether one procedure is more advantageous than the other.

Total hip replacement with a collarless polished cemented anatomic stem: clinical and gait analysis results at ten years follow-up

PURPOSE

The aim of this study was to determine outcomes of total hip replacement (THR) with the Lemania cemented femoral stem.

METHODS

A total of 78 THR patients were followed and compared to 17 "fit", healthy, elderly and 72 "frail" elderly subjects without THR, using clinical outcome measures and a portable, in-field gait analysis device at five and ten years follow-up.

RESULTS

Forty-one patients (53%), mean age 83.4 years, available at ten years follow-up, reported very good to excellent satisfaction. Mean Harris Hip and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were 81.2 and 10.5 points, respectively, with excellent radiological preservation of proximal femur bone stock. Spatial and temporal gait parameters were close to the fit group and better than the frail group.

CONCLUSIONS

Lemania THR demonstrated very good, stable clinical and radiological results at ten years in an older patient group, comparable to other cemented systems for primary THR. Gait analysis confirmed good walking performance in a real-life environment.

Postoperative gait analysis and hip muscle strength in patients with pelvic ring fracture

The aims of present study were (1) to determine changes in kinematic and kinetic variables at 3 and 12 months after open reduction and internal fixation (ORIF) of pelvic ring fracture and (2) to determine the factor(s) associated with gait disorders that correlate with gait parameters measured at 12 months after surgery. Nineteen patients with pelvic ring fractures underwent ORIF and examined at 3 and 12 months postoperatively. The study also included a similar number of age-matched control subjects. Peak hip abduction angle, peak hip extension moment in the stance, peak hip abduction moment, and peak ankle plantarflexion moment at 3 months after ORIF were significantly lower than the respective control values. At 12 months, complete recovery was noted in peak hip abduction moment and peak ankle plantarflexion moment, whereas the recovery in peak hip abduction angle and peak hip extension moment in the stance was partial. The existence of neurological lesions and strength asymmetry of hip abductor and adductor at 3 months post-ORIF correlated with decreased peak hip abduction moment after ORIF. Our results highlighted characteristic gait patterns up to 12 months after ORIF for pelvic fracture, and these patterns correlated with neurological lesion and weakness of hip abductor and adductor muscles.

A non-invasive biomechanical device and treatment for patients following total hip arthroplasty: results of a 6-month pilot investigation

BACKGROUND

The purpose of the study was to examine the effect of a foot-worn biomechanical device on the clinical measurements and gait patterns of patients with total hip arthroplasty (THA).

METHODS

Nineteen patients, up to 3 months post-THA, were enrolled to the study. Patients underwent a computerized gait analysis to calculate spatiotemporal parameters and completed the Western Ontario and McMaster Universities osteoarthritis index and the SF-36 health survey. Patients then began therapy with a non-invasive foot-worn biomechanical device coupled with a treatment methodology (AposTherapy). Patients received exercise guidelines and used the device daily during their regular activities at their own environment. Follow-up examinations were conducted after 4, 12, and 26 weeks of therapy. Repeated measures ANOVA was used to evaluate changes over time. The clinical significance of the treatment effect was evaluated by computing the Cohen's effect sizes (ES statistic).

RESULTS

After 26 weeks of therapy, a significant improvement was seen in gait velocity (50.3%), involved step length (22.9%), and involved single limb support (16.5%). Additionally, a significant reduction in pain (85.4%) and improvement in function (81.1%) and quality of life (52.1%) were noted.

CONCLUSIONS

Patients following THA demonstrated a significant improvement in gait parameters and in self-assessment evaluations of pain, function, and quality of life. We recommend further RCTs to examine the effect of this therapy compared to other rehabilitation modalities following THA and compared to healthy matched controls.

TRIAL REGISTRATION

Clinical trial registration number NCT01266382.

Gait deviations in individuals with inflammatory joint diseases and osteoarthritis and the usage of three-dimensional gait analysis

This chapter describes three-dimensional gait analysis and common gait deviations in adults with rheumatoid arthritis (RA) and osteoarthritis (OA). Furthermore, we describe changes in gait deviations following surgical and non-surgical interventions. Gait analysis is used to define gait deviations and to evaluate varying surgical approaches, types of surgeries and non-pharmacologic interventions. Most studies examine gait in adults with knee OA. Limitations of existing studies include small samples, poor selection of controls, sample heterogenecity, lack of baseline gait assessments and inconsistency in measurement. Across studies, time and distance parameters are generally used to provide a global measure of gait deviations. Individuals with RA and OA in the lower extremities exhibit reduced walking speed/cadence and decreased motion and moments in relation to healthy subjects. Future research should include larger sample sizes, the use of proper controls, pre- and post-assessments and identify gait abnormalities early in the disease process to minimise long-term consequences.

Sagittal plane gait characteristics in hip osteoarthritis patients with mild to moderate symptoms compared to healthy controls: a cross-sectional study

BACKGROUND

Existent biomechanical studies on hip osteoarthritic gait have primarily focused on the end stage of disease. Consequently, there is no clear consensus on which specific gait parameters are of most relevance for hip osteoarthritis patients with mild to moderate symptoms. The purpose of this study was to explore sagittal plane gait characteristics during the stance phase of gait in hip osteoarthritis patients not eligible for hip replacement surgery. First, compared to healthy controls, and second, when categorized into two subgroups of radiographic severity defined from a minimal joint space of ≤/>2 mm.

METHODS

Sagittal plane kinematics and kinetics of the hip, knee and ankle joint were calculated for total joint excursion throughout the stance phase, as well as from the specific events initial contact, midstance, peak hip extension and toe-off following 3D gait analysis. In addition, the Western Ontario and McMaster Universities Osteoarthritis Index, passive hip range of motion, and isokinetic muscle strength of hip and knee flexion and extension were included as secondary outcomes. Data were checked for normality and differences evaluated with the independent Student's t-test, Welch's t-test and the independent Mann-Whitney U-test. A binary logistic regression model was used in order to control for velocity in key variables.

RESULTS

Fourty-eight hip osteoarthritis patients and 22 controls were included in the final material. The patients walked significantly slower than the controls (p=0.002), revealed significantly reduced joint excursions of the hip (p<0.001) and knee (p=0.011), and a reduced hip flexion moment at midstance and peak hip extension (p<0.001). Differences were primarily manifested during the latter 50% of stance, and were persistent when controlling for velocity. Subgroup analyses of patients with minimal joint space ≤/>2 mm suggested that the observed deviations were more pronounced in patients with greater radiographic severity. The biomechanical differences were, however, not reflected in self-reported symptoms or function.

CONCLUSIONS

Reduced gait velocity, reduced sagittal plane joint excursion, and a reduced hip flexion moment in the late stance phase of gait were found to be evident already in hip osteoarthritis patients with mild to moderate symptoms, not eligible for total hip replacement. Consequently, these variables should be considered as key features in studies regarding hip osteoarthritic gait at all stages of disease. Subgroup analyses of patients with different levels of radiographic OA further generated the hypothesis that the observed characteristics were more pronounced in patients with a minimal joint space ≤2 mm.