The effect of early weight bearing on migration pattern of the uncemented CLS stem in total hip arthroplasty. Periprosthetic bone mineral density and fixation of the uncemented CLS stem related to different weight bearing regimes Antero-lateral minimal invasive (ALMI) approach for total hip arthroplasty technique and early results No adverse effects of early weight bearing after uncemented total hip arthroplastyA randomized study of 20 patients The effects of different weight-bearing regimes on press-fit cup stability: a randomised study with five years of follow-up using radiostereometry Unrestricted Weight Bearing and Intensive Physiotherapy after Uncemented Total Hip Arthroplasty Immediate weight bearing after uncemented total hip arthroplasty with an anteverted stem: A prospective randomized comparison using radiostereometry Are Hip Precautions Necessary Post Total Hip Arthroplasty? A Systematic Review High Incidence of Squeaking in THAs with Alumina Ceramic-on-ceramic Bearings Effects of a late-phase exercise program after total hip arthroplasty: a randomized controlled trial. Reduced patient restrictions following total hip arthroplasty: study protocol for a randomized controlled trial Comparison of gait in patients following a computer-navigated minimally invasive anterior approach and a conventional posterolateral approach for total hip arthroplasty: a randomized controlled trial. Does the Dual-Mobility Hip Prosthesis Produce Better Joint Kinematics During Extreme Hip Flexion Task? A randomized trial of ceramic-on-ceramic bearing versus ceramic-on-crossfire-polyethylene bearing in total hip arthroplasty: five-year outcomes. New two-incision minimally invasive total hip arthroplasty: comparison with the one-incision method Early complications of anterior supine intermuscular total hip arthroplasty. Early Migration Pattern of the Uncemented CLS Stem in Total Hip Arthroplasties A systematic review of psychological interventions in total hip and knee arthroplasty Acetabular Polyethylene Wear and Acetabular Inclination and Femoral Offset Hip external rotator exercise contributes to improving physical functions in the early stage after total hip arthroplasty using an anterolateral approach: a randomized controlled trial The gait of patients with one resurfacing and one replacement hip: a single blinded controlled study Leg length and offset differences above 5mm after total hip arthroplasty are associated with altered gait kinematics. Biomechanical reconstruction of the hip: a randomised study comparing total hip resurfacing and total hip arthroplasty.
Forty-two patients ( younger than 65 years ) with osteoarthritis were operated on with an uncemented CLS stem and r and omized to early unrestricted weight bearing combined with intensive physiotherapy or to partial weight bearing combined with self-training . Radiostereometric analysis showed 1.2 ( + 0.11 to -6.76 ) mm subsidence of the stem at 24 months in both groups . There was no significant difference in the migration pattern between the unrestricted and partial weight bearing groups . Actual loading on the operated leg , measured with the F-scan system , did not influence the migration of the stem . There was a strong correlation between the average subsidence at 3 and 24 months ( r = 0.96 ) . Early full weight bearing and active rehabilitation can be used for the uncemented CLS stem without increased risk of early loosening Background and purpose There is no consensus on the best rehabilitation regime after uncemented total hip arthroplasty . Theoretically , bone ingrowth into the implant should benefit from initial partial weight bearing . We investigated whether the degree of postoperative weight bearing influences the periprosthetic bone mineral density ( BMD ) and /or the stability of the CLS stem . Patients and methods 38 patients received an uncemented CLS stem  and were  r and omized  to either unrestricted postoperative weight bearing or to partial weight bearing for 3 months .  Periprosthetic BMD was measured in the 7 Gruen zones with DXA and the stability of the femoral stem was assessed by radiostereometric analysis ( RSA ) after surgery and at 3 , 12 , 24 , and 60 months . Results Periprosthetic BMD was not influenced by the type of postoperative weight bearing . BMD was reduced by 8–15 % in all Gruen zones at 3 months . Restoration toward initial BMD was observed in all zones except in zone 7 ( calcar region ) , where BMD was reduced by 22 % at 5 years . Immediate weight bearing after surgery had no influence on the stability of the CLS stem , as assessed by RSA . Interpretation Immediate full weight bearing after uncemented total hip arthroplasty is safe . There is no difference in the periprosthetic BMD or in stability of the stem as measured by RSA compared to partial weight bearing for 3 months . BMD is reduced by more than 20 % in the calcar region around a CLS stem after 5 years Introduction : Minimally invasive surgery represents one of the most recent techniques to have emerged within THA . In conventional THA , the incision typically measures 15–20 cm . Minimal invasive approach defined as less invasive to the skin , muscles , or bone may reduce complications and improve recovery time . A number of different approaches and methods have been described in literature . Purpose : This is a prospect i ve study describing the technique and early results of the modified antero-lateral minimal invasive ( ALMI ) approach and comparing our results to the results of other investigators interested in minimal invasive THA . Material s and methods : Seventy-five consecutive primary total hip arthroplasties ( cemented and cementless ) were done through a modified ALMI approach ( 6–8 cm ) , in which we kept the hip abductors intact . Neither special instruments nor specially design ed prostheses were needed . Minimum follow-up was 12 months . Results : The mean Harris hip score for patients after 12-month follow-up was 90 while the mean Merle d’Abugine mean score was 16.5 . Both scores reached almost the maximum values within 3 months after surgery . The cup abduction angle for 70 % patients was between 35 ° and 45 ° . No femoral stem mal-alignment was recorded . The mean operative time of cemented prosthesis was 65 min while that of the cementless prosthesis was 55 min . No wound complications or dislocations were recorded . All the patients were allowed to weight bear in the second post-operative day and involved in an early rehabilitation program . Conclusion : ALMI hip approach with sparing of hip abductors is safe and gives excellent orientation for positioning of prosthesis components . It also allows early and smooth post-operative rehabilitation with fast recovery of the patient in terms of weight bearing BACKGROUND Few guidelines are available whether early weight-bearing after an  uncemented total hip arthroplasty ( THA ) can be recommended or not . Stability and ingrowth may be jeopardized by immediate loading of the implant while functional recovery may be promoted and periprosthetic demineralization reduced . PATIENTS AND METHODS We did a prospect i ve study of 20 patients who were operated on with a hydroxyapatite-coated ( HA ) , uncemented total hip arthroplasty with a tapered stem because of unilateral arthrosis , and r and omized the patients to the immediate ( I ) or late ( L ) weight-bearing ( after 3 months ) group . The shoe on the operated side was equipped with an auditory device signaling when the patient placed a load on the extremity . The clinical assessment was done with the Harris hip score at the time of the operation and after 12 and 24 months . Radiographs and dual-energy x-ray absorptiometry ( DEXA ) were evaluated for migration , femoral remodeling and bone mineral density ( BMD ) after 3 , 6 , 12 and 24 months .  Tc-scintigraphy  was done after 6 , 12 and 24 months . RESULTS Postoperatively , the Harris hip score showed no group difference . After 3 months , we noted a large reduction in BMD around the stem prosthesis . This was most marked in the proximal regions and the bone loss was significantly larger in zone 1 , 4 and 5 in the L group . Distally , the BMD normalized with time , but the loss of bone persisted in the proximal zones after 24 months . An initial increase in the scintigraphic uptake ratio in all zones in both groups declined with time , but it was still increased on the operated side after 24 months . Several radiographic signs of bone remodeling were seen , but the patterns were similar in both groups . INTERPRETATION We found no adverse effect of immediate weight bearing with this prosthesis Purpose There is little evidence to support immediate weight bearing after uncemented total hip arthroplasty ( THA ) . Methods Thirty-seven patients with unilateral osteoarthritis of the hip received a press-fit cup . Cup stability was assessed with radiostereometry ( RSA ) over five years . Patients were r and omised to immediate full weight bearing , or partial weight bearing for three months . Results At five years , we found no difference in micromotion as assessed with radiostereometry . Numerically , there was more proximal translation and increased inclination with immediate weight bearing , but these values barely exceeded the precision limit for the method . Pooled data for the two groups revealed translations of 0.1 - 0.3 mm and rotations of 0.2 - 0.3 ° over the five year follow-up period . Conclusions We found no adverse effects of immediate weight bearing after THA in relation to stability of these press-fit cups . Early mobilisation might have other advantages Background and Aims : The effectiveness of partial weightbearing after hip surgery has been question ed as well as the need of intensive physiotherapy . Material and Methods : 36 patients ( average age 54.4 , 19 women ) operated with uncemented hip arthroplasty were r and omized either to unrestricted weightbearing ( UWB ) combined with intensive physiotherapy or to partial weightbearing ( PWB ) for 3 months combined with a short self-training program . The load during walking and the muscle strength ( MS ) in abduction was measured preoperative and subsequent up to 12 months . Results : The average peak load on the operated leg at one week was 39.0 kg for the UWB and 25.8 for the PWB group ( P = 0.009 ) while at three months 70.0 and 31.7 ( P = 0.001 ) respectively . At 6 and 12 months there were no differences between the groups . The muscle strength increased in both groups up to six months but there were no differences between the groups . Conclusions : Even though patients applied more load than the recommended 15 kg most patients were able to comply with partial weightbearing fairly well . The effect of intensive physiotherapy on the muscle strength after hip arthroplasty is question able Background In uncemented total hip arthroplasty with hydroxyapatite coating , early weight bearing is frequently practice d but there is still not much evidence to support this recommendation . Method In a prospect i ve r and omized study we evaluated the effect of partial and full weight bearing after  cementless total hip arthroplasty ( ABG ; Stryker-Howmedica ) using radiostereometric analysis ( RSA ) . Between February 1996 and February 2000 , 43 consecutive patients ( mean age 53 ( 41–63 ) years , 23 women ) with hip osteoarthrosis received an uncemented and hydroxyapatite-coated prosthesis with an anteverted stem . All patients were operated in a st and ardized way by three experienced surgeons and they were r and omized to partial ( P ) or full ( F ) weight bearing during the first 6 weeks after surgery . The patients in the partial weight bearing group were equipped with a pressuresensitive insole signaling when their load exceeded the prescribed weight limit . Results At 3-month follow-up , the mean proximal (+)/ distal ( - ) migration of the stem was -0.14 mm ( -1.93– 0.11 ) in group P and -0.31 mm ( -4.30–0.16 ) in group F ( p = 0.6 ) . At 1-year follow-up , the mean migration was –0.17 mm ( -2.18–0.21 ) and -0.28 mm ( -4.31–0.11 ) , respectively ( p = 0.9 ) . There was no significant difference in stem rotations either ( p < 0.2 ) . The cup translations , rotations , and femoral head penetration were similar in the two groups ( p < 0.1 ) . There were no re-operations during the first year . Interpretation We did not find any adverse effect of full weight bearing immediately after operation , which justifies use of this regimen after uncemented total hip arthroplasty of the ABG type Purpose : Total hip arthroplasty ( THA ) is a common and effective treatment of hip osteoarthritis . Activity restrictions known as hip pre caution s are widely practice d in rehabilitation post THA , aim ing to foster healing and prevent hip dislocation . The focused clinical question was : Does the application of hip pre caution s in patients post THA versus unrestricted activities significantly decrease the risk of prosthetic dislocation ? Methods : A comprehensive literature search was conducted for r and omized controlled trials or cohort studies with a comparative group and minimum 6 months follow-up , with dislocation as an end point . Retrieved titles were assessed independently by 2 review ers for inclusion and underwent st and ardized data extraction . Results : Title search produced 80 potentially relevant articles . Five articles were retrieved for data extraction of which 2 met a prior eligibility criteria . No eligible studies were found that concerned posterior approaches to hip arthroplasty , so the results of this review concern only anterolateral approaches . Neither included study showed any benefit of hip pre caution s in preventing dislocation . Conclusion : The rate of dislocation after anterolateral THA is low and is not improved by hip pre caution s. Hip pre caution s are associated with a slower return to activities , significant expense , and decreased patient satisfaction . Existing studies risk being compromised by a type II error , but a definitive study may be prohibitively large and expensive Abstract Ceramic-on-ceramic bearings in THA are a popular alternative to overcome wear concerns in traditional metal-polyethylene bearings . However , squeaking is a potentially worrisome phenomenon in ceramic-on-ceramic THAs which we observed in some of our patients . We review ed all 42 patients who underwent 43 ceramic-on-ceramic noncemented THAs during the time of the study .  Squeaking , defined as a reproducible sound of squeaking , clicking , or grating , occurred in nine of 43 implants ( 20.9 % ) . St and ard radiographs were normal . We used CT imaging to determine cup anteversion and inclination angles , comparing the squeaking hips with those of a r and omly selected control group , but found no differences . We then hypothesized specific design features ( stem size , cup size , head size , and neck length of the head ) would be risk factors for squeaking . We found a difference in neck length between squeaking and nonsqueaking implants . A neck length of −4 mm or shorter result ed in a relative risk of 5.56 ( 95 % confidence interval , 1.14–27.01 ) for squeaking . We found a high incidence of squeaking in our population , and we believe this phenomenon is an underreported side effect of these types of bearings . A short neck length of the femoral implant was a risk factor for squeaking in ceramic-on-ceramic THA . Level of Evidence : Level III , therapeutic study OBJECTIVE To investigate the effects of a late-phase exercise program for patients who underwent total hip arthroplasty ( THA ) 4 to 12 months earlier . DESIGN A single-blind , r and omized controlled trial . SETTING Exercises were performed in subjects ' homes . Exercise instruction and measurements taken before and after the trial were performed in an outpatient research and treatment center . PARTICIPANTS Convenience sample of 34 adults 4 to 12 months post-THA r and omly allocated to experimental or control groups . Twenty-eight subjects completed the study . INTERVENTION An 8-week , hip-exercise intervention , during which the control group received basic isometric and active range of motion exercises ; the experimental group received strength and postural stability exercises . MAIN OUTCOME MEASURES Score on the 12-Item Hip Question naire ; fear of falling ; hip flexor , extensor , abductor , and knee extensor muscle torque ; and postural stability in single stance . RESULTS There was a statistically significant improvement in all measures of self-perceived function , muscle strength ( hip flexors , 24.4 % ; hip extensors , 47.8 % ; hip abductors , 41.2 % ; knee extensors , 23.4 % ) , and postural stability ( 36.8 % ) in the experimental group and no significant change in the control group . Neither group had statistically significant changes in fear of falling measures . CONCLUSIONS An exercise program emphasizing weight bearing and postural stability significantly improved muscle strength , postural stability , and self-perceived function in patients 4 to 12 months after THA Background Total hip arthroplasty ( THA ) is a very common procedure in orthopedic surgery . In the Netherl and s , 25,642 primary THAs were performed in 2013 . Postoperative hip dislocation is one of the major complications and has been reported in 0.5 to 10.6 % of patients after primary THA.Several reports regarding the use of an anterolateral surgical approach have shown that a non-restriction or reduced restriction protocol does not increase the dislocation rate . For the posterolateral surgical approach it has been suggested that patient restrictions might be unnecessary but the amount of available literature is scarce . As such , r and omized controlled trials aim ed at investigating restrictions following THA using a posterior approach are strongly recommended . The aim of this prospect i ve r and omized controlled trial is to investigate the non-inferiority hypothesis concerning the early dislocation rate after THA in patients with and without the use of a reduced restriction protocol . Methods / Design After providing informed consent a group of 456 patients with symptomatic coxarthrosis will be r and omized to receive a THA either with care as usual , i.e. receiving postoperative restrictions including the advice to sleep in a supine position for the first 8 weeks postoperatively , or reduced restrictions with no recommendations regarding the position during sleeping . Primary outcome measure will be the percentage of early dislocations within the first 8 weeks after THA . Secondary outcome measures will be patient satisfaction , time to functional recovery , quality of sleep and patient ’s self-reported compliance with postoperative instructions . Discussion To our knowledge this will be the first r and omized controlled trial that compares a reduced restriction protocol with a restricted protocol following THA using a posterolateral surgical approach . Our hypothesis is that a reduced restriction protocol following THA with use of a posterolateral surgical approach has no influence on the early dislocation rate compared to a restricted protocol . Instead , embracing a reduced restriction protocol might even contribute to a higher quality of sleep , thereby facilitating a faster uptake and return to daily functions in patients after THA.Trial registration Clinical Trials.gov NCT02107248 , registration date 3 April 2014 Minimally invasive total hip arthroplasty ( MIS THA ) aims at minimizing damage to muscles and tendons to accelerate postoperative recovery . Computer navigation allows a precise prosthesis alignment without complete visualization of the bony l and marks during MIS THA . A r and omized controlled trial ( RCT ) was conducted to determine the effectiveness of a computer-navigated MIS anterior approach for THA compared to a conventional posterolateral THA technique on the restoration of physical functioning during recovery following surgery . Thirty-five patients underwent computer-navigated MIS THA via the anterior approach , and 40 patients underwent conventional THA using the conventional posterolateral approach .  Gait analysis was performed preoperatively , 6 weeks , and 3 and 6 months postoperatively using a body-fixed-sensor based gait analysis system . Walking speed , step length , cadence , and frontal plane angular movements of the pelvis and thorax were assessed . The same data were obtained from 30 healthy subjects . No differences were found in the recovery of spatiotemporal parameters or in angular movements of the pelvis and thorax following the computer-navigated MIS anterior approach or the conventional posterolateral approach . Although gait improved after surgery , small differences in several spatiotemporal parameters and angular movements of the trunk remained at 6 months postoperatively between both patient groups and healthy subjects BACKGROUND  Total hip arthroplasty ( THA )  using dual-mobility ( DM ) design permits larger hip range of motion . However , it is unclear how it benefits the patients during activities of daily living . The purpose was to compare kinematic variables of the operated limb between  THA patients using either DM or single-bearing ( SB ) implants during a squat task . METHODS Twenty-four THA patients were r and omly assigned to either a DM or SB implant and matched to 12 healthy controls ( CTRLs ) . They underwent 3-dimensional squat motion analysis  before and 9 months after surgery . Sagittal and frontal plane angles of the pelvis and the hip were analyzed using statistical parametric mapping . Paired analyses compared presurgery and postsurgery squat depth . RESULTS Peak sagittal pelvis angle of DM was closer to normal compared with that of SB . Both implant groups had similar hip angle patterns and magnitude but significantly lower than the CTRLs . SB reached a much large hip abduction compared with the other groups . Both surgical groups had significantly worst squat depth than the CTRLs . CONCLUSION Neither THA implant groups were able to return pelvis and hip kinematics to the level of CTRLs . The deficit of DM implants at the pelvis combined with the poorer functional scores should caution clinicians to use this implant design in active patients . SB design causes a larger hip abduction to reach their maximum squat depth . Post-THA rehabilitation should focus on improving joint range of motion and strength This study determined how ceramic-on-ceramic bearing THA affected joint-specific pain , function and stiffness in the first five postoperative years compared with ceramic-on-highly-crosslinked-polyethylene bearing THA .  Subjects less than 61 years of age were r and omized  to ceramic-on-ceramic ( CERAMIC ) [ n = 48 ] or ceramic-on-highly-crosslinked-polyethylene ( POLYETHYLENE ) [ n = 44 ] bearing THA . Subjects were assessed using the Western Ontario McMaster Osteoarthritis Index ( WOMAC ) and the R AND 12-Item Health Survey ( R AND -12 ) preoperatively , and at one and five years postoperatively . 92 subjects(50 ( 54 % ) males ; average age = 52 ( SD 6.6 ) years ) were enrolled . 78 ( 85 % ) subjects returned five years postoperatively . All subjects reported improvements at one and five years in all measured indices with no group differences detected . Seven ( 8 % ) subjects experienced postoperative THA complications , none related to bearing surfaces ; two subjects ( POLYETHYLENE ) required revision for instability . Both bearing surfaces provided excellent short-term results in younger subjects Background There has been increasing interest in performing total hip arthroplasty ( THA ) with minimally invasive surgery ( MIS ) . This study was conducted to examine the effectiveness of MIS-THA using the new two-incision technique versus the one-incision technique . Methods A consecutive series of 113 patients who underwent MIS-THAs ( 63 one-incision cases , 50 two-incision cases ) were studied .  One-incision THA was performed with a posterolateral approach . For the two-incision , the first incision for cup insertion was made over the anterolateral side of the hip . Intermuscular dissection was performed between the gluteus medius and the tensor fascia lata . The second incision , for stem insertion , was made on the posterolateral side of the hip along the fiber of the gluteus maximus . Intermuscular dissection was made between the gluteus medius and the piriformis . Results Postoperative rehabilitation was significantly more rapid in the new two-incision group compared to the group with one incision . Postoperatively , the Harris Hip Score and the Western Ontario and the McMaster Universities Osteoarthritis Index score were significantly different between the two groups , especially the functional sections . Conclusions The findings of this study show that our new two-incision MIS-THA is an excellent surgical modality that allows early rehabilitation Anterior supine intermuscular total hip arthroplasty ( THA ) performed on a fracture table has been increasingly used for primary THA . Accurate cup placement , low incidence of dislocation , shorter hospital stay , and faster return of function are potential benefits of the technique . However , a high complication rate , particularly during a surgeon 's learning curve , has been reported . A retrospective analysis of 61 consecutive anterior supine intermuscular primary THAs with at least 6-month follow-up was performed . All procedures were performed using the anterior supine intermuscular approach with cementless implants under fluoroscopic guidance on a fracture table . Prospect ively collected data were retrospectively review ed to evaluate the early complication rate and radiographic accuracy of implant placement . Five ( 8.2 % ) intraoperative complications were observed : including 3 trochanteric fractures and 2 calcar fractures , 4 of which required cable fixation during the index procedure . One nondisplaced trochanteric fracture was treated conservatively . One patient sustained an injury of the lateral femoral cutaneous nerve . Postoperative complications included 1 anterior dislocation , 1 infected superficial hematoma , 1 stem subsidence , and 1 loose stem , with the latter 2 presenting as increasing thigh pain postoperatively and requiring stem revision . The overall complication rate was 16.4 % ( 10/61 ) . Overall , 3 patients ( 4 hips ; 6.5 % ) required reoperation . No femoral or sciatic nerve injuries occurred , and no patient was diagnosed with venous thromboembolism . All intraoperative fractures occurred during the first 32 cases , and none during the last 29 cases . A potentially high incidence of complications with the anterior supine intermuscular THA exists during a surgeon 's learning curve in an academic setting We performed this investigation to determine the possible migration starting immediately after surgery and the effect of different weightbearing regimens on the migration pattern of an uncemented hip stem ( CLS ) . Stem migration was determined with radiostereometry analysis with baseline when the patients still were anesthetized . Subsequent examinations were done up to 1 year . Twenty-nine patients ( mean age , 55 years ; range , 26 - 63 years ) were r and omized to either unrestricted weightbearing combined with intensive physiotherapy  from the first day after surgery or to partial weightbearing and a conservative training regimen for the first 3 months after surgery . At 1 week , subsidence was −0.03 mm in the unrestricted weightbearing group and 0.01 mm in the partial weightbearing group . At 1 year , subsidence was 1.01 mm in the unrestricted weightbearing group and 0.51 mm in the partial weightbearing group . One patient in the unrestricted weightbearing group had revision surgery because of aseptic loosening at 1.5 years after surgery . The CLS stem did not have any migration from the end the surgery until 1 week , but there was small migration from 1 week to 3 months after which the stem remained stable . The degree of early weightbearing did not affect the migration pattern . Level of Evidence : Level I , therapeutic study ( r and omized study ) . See the Guidelines for Authors for a complete description of levels of evidence Background The current practice in elective orthopaedics does not routinely include psychological interventions despite evidence that psychological factors such as personality , anxiety , depression and negative thinking styles can influence outcomes and recovery from surgery . The objective of this paper was to review the effectiveness of psychological interventions used in conjunction with total hip ( THA ) and knee arthroplasty ( TKA ) , in improving patient reported joint outcomes . Methods An extensive literature search was conducted according to Preferred Reporting Items for Systematic review s and Meta-Analyses guidelines . Search terms included psychology , interventions , and orthopaedics . Articles were included if they were r and omised controlled trials ( RCTs ) of psychological interventions involving active patient participation measured with patient reported joint outcomes in patients undergoing hip or knee arthroplasty . Results A total of 19,489 titles were screened . Seven studies met the inclusion criteria and were included . Five of seven studies did not show improvements in patient reported outcomes after surgery . Specifically , psycho-education alone was not effective at improving patient reported joint outcomes in two out of two studies . Conclusion The current literature does not support routine psychological interventions for TKA and THA . However , it should be noted that the literature for psychological interventions in conjunction with TKA and THA is still in its infancy . This gap in the literature is surprising , considering the importance of the role of psychological factors in recovery . Further RCTs with long term follow ups , multidisciplinary involvement , and more comprehensive and focused interventions that go beyond educating patients are needed . Future studies should account for the dem and effect , include measures of psychological variables to determine whether psychological interventions are more beneficial for some patients compared to others , and compare the different modes of delivery and timing of interventions to determine the optimal nature and duration of psychological interventions for TKA and THA Abstract Restoration of femoral offset and acetabular inclination may have an effect on polyethylene ( PE ) wear in THA . We therefore assessed the effect of femoral offset and acetabular inclination ( angle ) on acetabular conventional ( not highly cross-linked ) PE wear in uncemented THA . We prospect ively followed 43 uncemented THAs for a minimum of 49 months ( mean , 64 months ; range , 49–88 months ) .  Radiographs were assessed for femoral offset , acetabular inclination , and  conventional PE wear . The mean ( ± st and ard deviation ) linear wear rate in all THAs was 0.14 mm/year ( ± 0.01 mm/year ) and the mean volumetric wear rate was 53.1 mm3/year ( ± 5.5 mm3/year ) . In THAs with an acetabular angle less than 45 ° , the mean wear was 0.12 mm/year ( ± 0.01 mm/year ) compared with 0.18 mm/year ( ± 0.02 mm/year ) in those with a reconstructed acetabular angle greater than 45 ° . Reproduction of a reconstructed femoral offset to within 5 mm of the native femoral offset was associated with a reduction in conventional PE wear ( 0.12 mm/year versus 0.16 mm/year ) . Careful placement of the acetabular component to ensure an acetabular angle less than 45 ° in the reconstructed hip allows for reduced conventional PE wear . Level of Evidence : Level II , prospect i ve study . See Guidelines for Authors for a complete description of levels of evidence Abstract Purpose : The purpose of this study was to investigate the effects of an exercise program focusing on hip external rotator muscle on physical recovery in the early post-operative period of total hip arthroplasty ( THA ) . Methods : Patients who underwent THA were r and omized to an exercise group ( n = 14 ) or a control group ( n = 14 ) . In exercise group , the hip external rotator exercise program was performed 5 times per week for four weeks . Outcome measures were hip pain , hip range of motion , muscle strength of lower extremity and Timed Up and Go ( TUG ) test . Results : Both the hip abductor strength ( effect size = 0.60 ) and TUG test ( effect size= −0.53 ) in the exercise group improved significantly after the intervention . Conclusions : The results of the present study demonstrated that exercise program focusing on hip external rotator muscle was an effective intervention , especially in improving both hip abductor strength and walking ability in the acute post-THA stage . Implication for Rehabilitation After THA , in order to safely progress patients back to their desired activity level , there is a need to develop rehabilitation strategies to expedite and promote the recovery during the acute postoperative period . Exercise program focusing on hip external rotator muscle may lead to significant improvement of hip abductor muscle strength and gait ability in the acute post-THA stage Purpose sPost arthroplasty gait analysis has up till now been performed on subjects walking slowly on flat ground rather than challenging them at faster speeds or walking uphill . We therefore asked : ( 1 ) Is there a measurable difference in the performance of  hip resurfacing arthroplasty ( HRA )  and  total hip arthroplasty ( THA ) limbs at patients ’ self-determined fastest walking speeds and steepest inclines ? and ( 2 ) Is there a relationship between the observed differences between the gait of HRA and THA implanted limbs and patient walking speeds and inclines . Methods In an ethically approved study we recruited patients with bilateral hip arthroplasties : one HRA and one THA . Nine subjects were assessed using an instrumented treadmill at a range of speeds and inclines by a blinded observer . The ground reaction forces of subjects were recorded and an age , sex and BMI matched control group was used for comparison . Results Increasing walking speed correlated strongly with between leg differences in weight acceptance ( r = 0.9 , p = 0.000 ) and push-off force ( r = 0.79 , p = 0.002 ) . HRA implanted limbs accepted significantly more weight at top walking speeds ( 1208 N ± 320 versus 1279 N ± 370 , p = 0.026 ) and pushed off with greater force when walking uphill ( 818 N ± 163 versus 855 ± 166 , p = 0.012 ) . HRA limbs more closely approximated to the gait of the normal control group . Conclusions Arthroplasty implants do have an impact on the gait characteristics of patients . Differences in gait are more likely to be evident when assessment is made at fast speeds and walking uphill . This study suggests that HRA may enable a more normal gait We aim ed to investigate the relationship between postoperative leg length/offset ( LL/OS ) reconstruction and gait performance after  total hip arthroplasty ( THA ) . In the course of a prospect i ve r and omized controlled trial , 60 patients with unilateral hip arthrosis received cementless THA  through a minimally-invasive anterolateral surgical approach . One year post-operatively , LL and global OS restoration were analyzed and compared to the contralateral hip on AP pelvic radiographs . The combined postoperative limb length/OS reconstruction of the operated hip was categorized as restored ( within 5 mm ) or non-restored ( more than 5 mm reduction or more than 5 mm increment ) . The acetabular component inclination , anteversion and femoral component anteversion were evaluated using CT scans of the pelvis and the femur . 3D gait analysis of the lower extremity and patient related outcome measures ( HHS , HOOS , EQ-5D ) were obtained pre-operatively , six months and twelve months post-operatively by an observer blinded to radiographic results . Component position of cup and stem was comparable between the restored and non-restored group . Combined LL and OS restoration within 5 mm result ed in higher Froude number ( p<0.001 ) , normalized walking speed ( p<0.001 ) and hip range-of-motion ( ROM ) ( p=0.004 ) during gait twelve months postoperatively , whereas gait symmetry was comparable regardless of LL and OS reconstruction at both examinations . Clinical scores did not show any relevant association between the accuracy of LL or OS reconstruction and gait six/twelve months after THA . In summary , postoperative LL/OS discrepancies larger than 5 mm relate to unphysiological gait kinematics within the first year after THA . DRKS00000739 , German Clinical Trials Register We have compared the biomechanical nature of the reconstruction of the hip in conventional total hip arthroplasty ( THA ) and surface replacement arthroplasty ( SRA ) in a r and omised study involving 120 patients undergoing unilateral primary hip replacement . The contralateral hip was used as a control . Post-operatively , the femoral offset was significantly increased with THA ( mean 5.1 mm ; -2.8 to 11.6 ) and decreased with SRA ( mean -3.3 mm ; -8.9 to 8.2 ) . Femoral offset was restored within sd 4 mm in 14 ( 25 % ) of those with THA and in 28 ( 57 % ) of the patients receiving SRA ( p < 0.001 ) . In the THA group , the leg was lengthened by a mean of 2.6 mm ( -6.04 to + 12.9 ) , whereas it was shortened by a mean of 1.9 mm ( -7.1 to + 2.05 ) in the SRA group , compared with the contralateral side . Leg-length ine quality was restored within sd 4 mm in 42 ( 86 % ) of the SRA and 33 ( 60 % ) of the THA patients . The radiological parameters of acetabular reconstruction were similar in both groups . Restoration of the normal proximal femoral anatomy was more precise with SRA . The enhanced stability afforded by the use of a large-diameter femoral head avoided over-lengthening of the limb or increased offset to improve soft-tissue tension as occurs sometimes in THA . In a subgroup of patients with significant pre-operative deformity , restoration of the normal hip anatomy with lower pre-operative femoral offset or significant shortening of the leg was still possible with SRA
We found moderate to strong evidence that no adverse effects on subsidence and osseous integration of the femoral stem after uncemented THA occur after immediate UWB .
The aim of this systematic review was to find evidence -based support in the literature to allow immediate unrestricted weight bearing after  primary uncemented total hip arthroplasty ( THA ) .
Accelerated rehabilitation programs for THA are becoming increasingly popular to shorten hospital stay and to facilitate rapid restoration of function .
The goals of these rehabilitation programs could be more easily achieved if immediate unrestricted weight bearing ( UWB ) could be allowed after a THA .
So far , however , immediate weight bearing is frequently contraindicated in widely accepted protocol s for uncemented THA due to fear for subsidence and absence of osseous integration of the femoral stem .
Thus , frequently protected weight bearing and restricted activities are still advocated for at least 6 weeks after surgery .
In addition , we analyzed the literature to come to a recommendation on gait pattern and walking aid .