Robot-assisted primary cementless total hip arthroplasty with a short femoral stem: a prospective randomized short-term outcome study [Clinical outcome following robotic assisted versus conventional total hip arthroplasty: a controlled and prospective study of seventy-one patients]. A Comparison between Robotic-assisted and Manual Implantation of Cementless Total Hip Arthroplasty Robot-assisted primary cementless total hip arthroplasty with a short femoral stem: a prospective randomized short-term outcome study. Effect of robotic milling on periprosthetic bone remodeling. Robot‐assisted total hip arthroplasty: Clinical outcomes and complication rate Comparison of Robotic-assisted and Conventional Acetabular Cup Placement in THA: A Matched-pair Controlled Study Comparison of robotic-assisted and conventional manual implantation of a primary total knee arthroplasty.
Abstract Background : Recently , two topical issues in total hip arthroplasty ( THA ) have been robot-assisted surgery and use of a short stem . The purpose of this study was to evaluate the effects of robotic milling on the accuracy of short femoral stem positioning and on the short-term clinical outcome in THA using a prospect i ve , r and omized design . Methods : We r and omized 54 patients into two groups , either robotic milling group or manual rasping group .  The patients were assessed clinical ly and radiographically at 8 weeks , 5 months , 12 months , and 24 months . Results : Robotic milling group had a significantly longer operation time , requiring on average 8.9 min for registration and 11.2 min for milling . On the other h and , robotic milling group showed superior results in terms of stem alignment and leg length e quality . Two intraoperative femoral fractures occurred only in manual rasping group . Harris hip scores and WOMAC scores at 24 months postoperatively were similar in both groups . No complications including stem loosening , infection , nerve palsy , or dislocation were encountered in either group during the follow-up period . Conclusions : The present study suggested that robot-assisted short stem THA could increase the accuracy of stem alignment , improve leg length e quality , and help reduce the risk of intraoperative femoral fracture as compared with manual rasping . However , the clinical outcome scores did not differ between the two groups at the time of short-term follow-up . Long-term follow-up is needed to determine whether there will be a long-term clinical relevance of robot-assisted implantation of short femoral stems in THA AIM Robotic assisted total hip arthroplasty  remains controversial , since wider exposure of the proximal femur and placement of the leg in maximal hip adduction and external rotation using a rigid leg-holder apparatus may impair significantly the hip abductors . Consequently , it is the purpose of this study to analyse and report both clinical outcome and hip abductor function following robotic assisted versus conventional total hip arthroplasty . MATERIAL AND METHODS 36 robotic-assisted ( CASPAR , Orto-Maquet , Rastatt , Germany ) and 35 conventional cementless total hip arthroplasties  were followed on average for 18 months regarding incidence of complications , Harris hip score , the scoring system according to Merle d'Aubigné and Postel , hip abductor function ( using a spring-balance ) , and incidence of Trendelenburg 's sign ( according to the Kuhfuss-classification ) . Statistical analysis was performed in case of continuous data using the t test and the Mann-Whitney test , respectively , and in case of categorical data using Fisher 's exact test and the chi-squared test , respectively . The level of significance was set as p < 0.05 . RESULTS Average duration of surgery ( CASPAR : 100.6 min ; conventional : 51.5 min ; p < 0.0001 ) as well as average loss of haemoglobin ( CASPAR : 4.5 mg/dL ; conventional : 3.3 mg/dL ; p = 0.0002 ) differed significantly , whereas the incidence of complications ( CASPAR : two dislocations , one sciatic paresis , one deep infection ; conventional : one dislocation , two fissures ) , revision rate ( CASPAR : 5.6 % ; conventional : 2.9 % ) , and incidence of heterotopic ossifications ( CASPAR : 30.6 % ; conventional : 17.1 % ) was comparable following both procedures ( p > 0.05 ) . Improvement of the Harris hip score also was comparable in both groups ( CASPAR : 40.9 to 86.1 points ; conventional : 39.5 to 88.0 points ; p = 0.21 ) , whereas improvement of the score according to Merle d'Aubigné and Postel was significantly greater following the manual procedure ( CASPAR : 10.1 to 16.0 points ; conventional : 8.3 to 16.6 points ; p < 0.0001 ) . Differences between the two groups were also significant regarding hip abductor function ( CASPAR : 76.1 % ; conventional : 93.8 % of the contralateral hip ; p < 0.0001 ) and incidence of Trendelenburg 's sign ( CASPAR : 61.1 % ; conventional : 25.7 % ; p = 0.0014 ) . CONCLUSION The significant functional impairment following robotic assisted THA should be taken critically into consideration prior to initiating such procedure Background The benefits of robotic techniques for implanting femoral components during THA are still controversial . Questions / Purpose sThe purpose of this study was to prospect ively compare the results and complications of robotic-assisted and h and -rasping stem implantation techniques . Method The minimum followup was 5 years ( mean , 67 months ; range , 60–85 months ) . One hundred forty-six primary THAs on 130 patients were included in this study .  Robot-assisted primary THA was performed on 75 hips and a h and -rasping technique was used on 71 hips . Results At 2 and 3 years postoperatively , the Japanese Orthopaedic Association ( JOA ) clinical score was slightly better in the robotic-assisted group . At 5 years followup , however , the differences were not significant . Postoperative limb lengths of the robotic-milling group had significantly less variance than the h and -rasping group . At 2 years postoperatively , there was significantly more stress shielding of the proximal femur in the h and -rasping group ; this difference was more significant 5 years postoperatively . Conclusions Substantially more precise implant positioning seems to have led to less variance in limb-length ine quality and less stress shielding of the proximal femur 5 years postoperatively . Level of Evidence Level II , therapeutic study . See Guidelines for Authors for a complete description of levels of evidence BACKGROUND Recently , two topical issues in total hip arthroplasty ( THA ) have been robot-assisted surgery and use of a short stem . The purpose of this study was to evaluate the effects of robotic milling on the accuracy of short femoral stem positioning and on the short-term clinical outcome in THA using a prospect i ve , r and omized design . METHODS We r and omized 54 patients into two groups , either robotic milling group or manual rasping group .  The patients were assessed clinical ly and radiographically at 8 weeks , 5 months , 12 months , and 24 months . RESULTS Robotic milling group had a significantly longer operation time , requiring on average 8.9 min for registration and 11.2 min for milling . On the other h and , robotic milling group showed superior results in terms of stem alignment and leg length e quality . Two intraoperative femoral fractures occurred only in manual rasping group . Harris hip scores and WOMAC scores at 24 months postoperatively were similar in both groups . No complications including stem loosening , infection , nerve palsy , or dislocation were encountered in either group during the follow-up period . CONCLUSIONS The present study suggested that robot-assisted short stem THA could increase the accuracy of stem alignment , improve leg length e quality , and help reduce the risk of intraoperative femoral fracture as compared with manual rasping . However , the clinical outcome scores did not differ between the two groups at the time of short-term follow-up . Long-term follow-up is needed to determine whether there will be a long-term clinical relevance of robot-assisted implantation of short femoral stems in THA The ROBODOC system has provided better fit and fill of the stem and less destruction of the bony architecture than with manual surgery . These benefits might affect femoral periprosthetic bone remodeling . We evaluated the effects of robotic milling in cementless total hip arthroplasty ( THA ) in a longitudinal 24-month follow-up study using dual energy X-ray absorptiometry ( DEXA ) and plain radiographs of 29 patients ( 31 hips ) after ROBODOC THA and 24 patients ( 27 hips ) after manual THA with the same stem design . To minimize the influence of other factors on bone remodeling , only female osteoarthritis patients , who had no drugs that might affect bone metabolism were enrolled . Significantly less bone loss occurred at the proximal periprosthetic areas in the ROBODOC group . In zone 1 , the decrease was 15.5 versus 29.9 % using conventional rasping ; in zone 7 , the loss was 17.0 % with ROBODOC compared to 30.5 % with conventional rasping ( p < 0.05 ) . On radiographs , endosteal spot welds in the proximal medial portion were more pronounced in the ROBODOC group ( 48 vs. 11 % in the conventional group , p < 0.05 ) . Our results suggest that robotic milling is effective in facilitating proximal load transfer around the femoral component and minimizing bone loss after cementless THA BACKGROUND The purpose of this study was to report minimum 2-year outcomes and complications for robotic-arm-assisted total hip arthroplasty ( THA )  . METHODS Data were prospect ively collected and retrospectively review ed between June 2011 and April 2014 . Inclusion criteria were primary robotic-arm-assisted THAs treating idiopathic osteoarthritis with ≥ 2-year follow-up .  Demographics , operating time , complications , 2-year outcome scores and satisfaction , and subsequent surgeries were recorded . RESULTS There were 181 cases eligible for inclusion , of which 162 ( 89.5 % ) had minimum 2-year follow-up . At the latest follow-up , the mean visual analogue scale was 0.7 , satisfaction was 9.3 , Harris hip score was 91.1 and forgotten joint score was 83.1 . Six ( 3.7 % ) intraoperative complications and six ( 3.7 % ) postoperative complications were reported . No leg length discrepancies ( LLDs ) or dislocations were reported . CONCLUSIONS Robotic-arm-assisted THA demonstrates favourable short-term outcomes and does not result in a higher complication rate compared to non-robotic THA as reported by the literature Background Improper acetabular component orientation in THA has been associated with increased dislocation rates , component impingement , bearing surface wear , and a greater likelihood of revision . Therefore , any reasonable steps to improve acetabular component orientation should be considered and explored . Questions / purpose sWe therefore sought to compare THA with a robotic-assisted posterior approach with manual alignment techniques through a posterior approach , using a matched-pair controlled study design , to assess whether the use of the robot made it more likely for the acetabular cup to be positioned in the safe zones described by Lewinnek et al. and Callanan et al. Methods Between September 2008 and September 2012 , 160 THAs were performed by the senior surgeon . Sixty-two patients ( 38.8 % ) underwent THA using a conventional posterior approach , 69 ( 43.1 % ) underwent robotic-assisted THA using the posterior approach , and 29 ( 18.1 % ) underwent radiographic-guided anterior-approach THAs .  From September 2008 to June 2011 , all patients were offered anterior or posterior approaches regardless of BMI and anatomy . Since introduction of the robot in June 2011 , all THAs were performed using the robotic technique through the posterior approach , unless a patient specifically requested otherwise . The radiographic cup positioning of the robotic-assisted THAs was compared with a matched-pair control group of conventional THAs performed by the same surgeon through the same posterior approach . The safe zone ( inclination , 30 ° –50 ° ; anteversion , 5 ° –25 ° ) described by Lewinnek et al. and the modified safe zone ( inclination , 30 ° –45 ° ; anteversion , 5 ° –25 ° ) of Callanan et al. were used for cup placement assessment . Matching criteria were gender , age ± 5 years , and ( BMI ) ± 7 units . After exclusions , a total of 50 THAs were included in each group . Strong interobserver and intraobserver correlations were found for all radiographic measurements ( r > 0.82 ; p < 0.001 ) . Results One hundred percent ( 50/50 ) of the robotic-assisted THAs were within the safe zone described by Lewinnek et al. compared with 80 % ( 40/50 ) of the conventional THAs ( p = 0.001 ) . Ninety-two percent ( 46/50 ) of robotic-assisted THAs were within the modified safe zone described by Callanan et al. compared with 62 % ( 31/50 ) of conventional THAs p ( p = 0.001 ) . The odds ratios for an implanted cup out of the safe zones of Lewinnek et al. and Callanan et al. were zero and 0.142 , respectively ( 95 % CI , 0.044 , 0.457 ) . Conclusions Use of the robot allowed for improvement in placement of the cup in both safe zones , an important parameter that plays a significant role in long-term success of THA . However , whether the radiographic improvements we observed will translate into clinical benefits for patients —such as reductions in component impingement , acetabular wear , and prosthetic dislocations , or in terms of improved longevity — remains unproven . Level of Evidence Level III , therapeutic study . See the Instructions for Authors for a complete description of levels of evidence This study was aim ed to compare robotic-assisted implantation of a total knee arthroplasty with conventional manual implantation . We controlled , r and omized , and review ed 72 patients for total knee arthroplasty assigned to undergo either conventional manual implantation ( excluding navigation-assisted implantation cases ) of a Zimmer LPS prosthesis ( Zimmer , Warsaw , Ind ) ( 30 patients : group 1 ) or robotic-assisted implantation of such a prosthesis ( 32 patients : group 2 ) . The femoral flexion angle ( gamma angle ) and tibial angle ( delta angle ) in the lateral x-ray of group 1 were 4.19 + /- 3.28 degrees and 89.7 + /- 1.7 degrees , and those of group 2 were 0.17 + /- 0.65 degrees and 85.5 + /- 0.92 degrees . The major complications were from improper small skin incision during a constraint attempt of minimally invasive surgery and during bulk fixation frame pins insertion . Robotic-assisted technology had definite advantages in terms of preoperative planning , accuracy of the intraoperative procedure , and postoperative follow-up , especially in the femoral flexion angle ( gamma angle ) and tibial flexion angle ( delta angle ) in the lateral x-ray , and in the femoral flexion angle ( alpha angle ) in the anteroposterior x-ray . But a disadvantage was the high complication rate in early stage
Moreover , postoperative complications ( eg , dislocation and revision surgery ) were less frequent in the CM group than in the RA group .
Conclusion Compared with the CM approach , the RA approach yields better radiological outcomes and fewer intraoperative complications in THA , but similar functional scores
Abstract Background Several studies have compared robotics‐assisted ( RA ) and conventional manual ( CM ) approaches for total hip arthroplasty ( THA ) , but their results are controversial .