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Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_4 | Pages 52 - 52
1 Mar 2021
Harris A O'Grady C Sensiba P Vandenneucker H Huang B Cates H Christen B Hur J Marra D Malcorps J Kopjar B
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Patients ≤ 55 years have a high primary TKA revision rate compared to patients >55 years. Guided motion knee devices are commonly used in younger patients yet outcomes remain unknown. In this sub-group analysis of a large multicenter study, 254 TKAs with a second-generation guided motion knee implant were performed between 2011–2017 in 202 patients ≤ 55 years at seven US and three European sites. Revision rates were compared with Australian Joint Registry (AOANJRR) 2017 data. Average age 49.7 (range 18–54); 56.4% females; average BMI 34 kg/m2; 67.1% obese; patellae resurfaced in 98.4%. Average follow-up 4.2 years; longest follow-up six years; 27.5% followed-up for ≥ five years. Of eight revisions: total revision (one), tibial plate replacements (three), tibial insert exchanges (four). One tibial plate revision re-revised to total revision. Revision indications were mechanical loosening (n=2), infection (n=3), peri-prosthetic fracture (n=1), and instability (n=2). The Kaplan-Meier revision estimate was 3.4% (95% C.I. 1.7% to 6.7%) at five years compared to AOANJRR rate of 6.9%. There was no differential risk by sex. The revision rate of the second-generation guided motion knee system is lower in younger patients compared to registry controls.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_4 | Pages 51 - 51
1 Mar 2021
Harris A O'Grady C Sensiba P Vandenneucker H Huang B Cates H Christen B Hur J Marra D Malcorps J Kopjar B
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Outcomes for guided motion primary total knee arthroplasty (TKA) in obese patients are unknown. 1,684 consecutive patients underwent 2,059 primary TKAs with a second-generation guided motion implant between 2011–2017 at three European and seven US sites. Of 2,003 (97.3%) TKAs in 1,644 patients with BMI data: average age 64.5 years; 58.4% females; average BMI 32.5 kg/m2; 13.4% had BMI ≥ 40 kg/m2. Subjects with BMI ≥ 40 kg/m2 had longest length of hospital stay (LOS) at European sites; LOS similar at US sites. Subjects with BMI ≥ 40 kg/m2 (P=0.0349) had longest surgery duration. BMI ≥ 40 kg/m2 had more re-hospitalizations or post-TKA reoperations than BMI < 40 kg/m2 (12.7% and 9.2% at five-year post-TKA, P<0.0495). Surgery duration and long-term complication rates are higher in patients with BMI ≥ 40 kg/m2, but device revision risk is not elevated.


Aims

The aim of this study was to compare patient-reported outcome measures (PROMs) and the Single Assessment Numerical Evaluation (SANE) score in patients treated with a volar locking plate for a distal radial fracture.

Methods

This study was a retrospective review of a prospective database of 155 patients who underwent internal fixation with a volar locking plate for a distal radial fracture between August 2014 and April 2017. Data which were collected included postoperative PROMs (Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) and Patient-Rated Wrist Evaluation (PRWE)), and SANE scores at one month (n = 153), two months (n = 155), three months (n = 144), six months (n = 128), and one year (n = 73) after operation. Patients with incomplete data were excluded from this study. Correlation and agreement between PROMs and SANE scores were evaluated. Subgroup analyses were carried out to identify correlations according to variables such as age, the length of follow-up, and subcategories of the PRWE score.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 96 - 96
1 Feb 2020
Harris A Christen B Malcorps J O'Grady C Sensiba P Vandenneucker H Huang B Cates H Hur J Marra D Kopjar B
Full Access

Introduction

Patients ≤ 55 years have a high primary TKA revision rate compared to patients >55 years. Guided motion knee devices are commonly used in younger patients yet outcomes remain unknown.

Materials and Methods

In this sub-group analysis of a large multicenter study, 254 TKAs with a second-generation guided motion knee implant (Journey II Bi-Cruciate Stabilized Knee System, Smith & Nephew, Inc., Memphis) were performed between 2011–2017 in 202 patients ≤ 55 years at seven US and three European sites. Revision rates were compared with Australian Joint Registry (AOANJRR) 2017 data.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 95 - 95
1 Feb 2020
Harris A Christen B Malcorps J O'Grady C Sensiba P Vandenneucker H Huang B Cates H Hur J Marra D Kopjar B
Full Access

Introduction/Aim

Outcomes for guided motion primary total knee arthroplasty (TKA) in obese patients are unknown.

Materials and Methods

1,684 consecutive patients underwent 2,059 primary TKAs with a second-generation guided motion implant (Journey II Bi-Cruciate Stabilized Knee System, Smith & Nephew, Inc., Memphis) between 2011–2017 at three European and seven US sites.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 143 - 143
1 May 2016
Yoon S Lee C Hur J Kwon O Lee H
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Introduction

Mechanically aligned total knee arthroplasty(TKA) relies on restoring the hip-knee-ankle angle of the limb to neutral or as close to a straight line as possible. This principle is based on studies that suggest limb and knee alignment is related long term survival and wear. For that cause, there has been recent attention concerning computer-assisted TKA and robot is also one of the most helpful instruments for restoring neutral alignment as known. But many reported data have shown that 20% to 25% of patients with mechanically aligned TKA are dissatisfied. Accordingly, kinematically aligned TKA was implemented as an alternative alignment strategy with the goal of reducing prevalence of unexplained pain, stiffness, and instability and improving the rate of recovery, kinematics, and contact forces. So, we want to report our extremely early experience of robot-assisted TKA planned by kinematic method.

Materials and Methods

This study evaluated the very short term results (6 weeks follow up) after robot-assisted TKA aligned kinematically. 50 knees in 36 patients, who could be followed up more than 6 weeks after surgery from December 2014 to January 2015, were evaluated prospectively. The diagnosis was primary osteoarthritis in all cases. The operation was performed with ROBODOC (ISS Inc., CA, USA) along with the ORTHODOC (ISS Inc., CA, USA) planning computer. The cutting plan was made by single radius femoral component concept, each femoral condyles shape-matched method along the transverse axis using multi-channel CT and MRI to place the implant along the patient's premorbid joint line. Radiographic measurements were made from long bone scanograms. Clinical outcomes and motion were measured preoperatively and 6 weeks postoperatively.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 367 - 367
1 Mar 2013
Yoon S Lee C Hur J Kwon O Trabish M Lee H Park J
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Introduction

The success of total knee arthroplasty depends on many factors, including the preoperative condition of the patient, the design and materials of the components and surgical techniques. It is important to position the femoral and tibial components accurately and to balance the soft tissues. Malpositioning of the component can lead to failures due to aseptic loosening, instability, polyethylene wear and dislocation of the patella. In order to improve post-operative alignment, computer-aid systems have been developed for total knee arthroplasty. Many clinical and experimental studies of these systems have shown that the accuracy of implanted components can be improved in spite of the increase in costs and operating time. This may not, however, improve the outcome in the short-term. Restoration of the normal mechanical axis of the knee and balancing of the surrounding soft tissues have been shown to have an important bearing on the final outcome of knee replacement operations. In severely deformed knees, whether varus or valgus, these goals may be difficult to achieve. We compared the radiologic results of the mechanical axis and implant position of Total Knee Arthroplasty using a robot-assisted method with conventional manually implanted method in severe varus deformed knee.

Materials and Methods

A data set of 50 consecutive cases that were performed from April 2007 to December 2010 using the robot assisted TKA(Group A) were compared with a data set of 50 consecutive cases from the same period that were done using conventional manual TKA(Group B). All cases had a preoperative mechanical varus deformity >15° and one brand of implant was used on all cases. The diagnosis was primary osteoarthritis in all knees. The operations were performed by one-senior author with the same robot system, ROBODOC (ISS Inc., CA, USA) along with the ORTHODOC (ISS Inc., CA, USA) planning computer. (See Figure 1.) The radiological evaluations included mechanical axis, implant position (α,β,γ,δ angle) according to the system of American Knee Society.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 366 - 366
1 Mar 2013
Yoon S Lee C Hur J Kwon O Trabish M Lee H Park J
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Introduction

Since Smith-Peterson's glass mold arthroplasty in 1939, hip resurfacing arthroplasty was developed and introduced to orthopaedic surgery field but it had many problem like early loosening. Recently it is being popular for some indication as development of new implant design and manufacturing. There are still many suggested advantages of hip resurfacing arthroplasty. These include bone conservation, improved function as a consequence of retention of the femoral head and neck and more precise biomechanical restoration, decreased morbidity at the time of revision arthroplasty, reduced dislocation rates, normal femoral loading and reduced stress-shielding, simpler management of a degenerated hip with a deformity in the proximal femoral metaphysic, an improved outcome in the event of infection, and a reduced prevalence of thromboembolic phenomena as a consequence of not using instruments in the femur. But, there are limited or inconsistent data to support some of these claims regarding the benefits of hip resurfacing including the potential for a more natural feel because of the minimal disturbance of the proximal part of the femur resulting in a better and faster functional outcome. We evaluate the short term results of hip resurfacing arthroplasty using custom patient-specific tooling for prosthesis placement for better standardization.

Materials and Methods

40 cases, 36 patients(male:20, female:16) those of who were candidates of a Hip Resurfacing procedure, participated in the study. Mean follow up period was 2.5 years (8 months ∼3 years). A CT scan was performed on each patient and a 3D model was generated using the computer tomography dataset. From this model a bone-surface skin was extracted and this data set was used to create a personalized jig. Detailed analysis of the native bone structure was then used to preoperatively plan the appropriate size and position of the implant. A mean 7 degree corrective valgus angle was prescribed on all cases. Postoperative radiological datasets were superimposed onto preoperative plan position and offsets were measured. Operative times were recorded per step during the procedure. Surgeon comfort and ease of use was also noted.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 126 - 127
1 Mar 2010
Won Y Piao T Hur J Cui W Rudrappa GH
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Introduction: Electromagentic Navigation(EM) system has been introduced in total knee arthroplasty to increase the accuracy of lower limb alignment and positioning of the implant. EM navigation systems offer several potential advantages over their infrared counterparts. To our best knowledge, there have been scarce clinical results reported In order to obtain optimal results, a certain period of learning curve may be necessary. We have compared our first 100 cases of total knee arthroplasty to our last 100 cases in order to verify the clinical accuracy, efficacy and learning curve.

Methods: From July 2006 to November 2007, 138 patients underwent 200 serial primary TKA operations by a single surgeon with the assistance of Electromagnetic Navigation system. The 200 TKA cases were divided into two groups; the first 100 and the next 100 cases. We have compared the deviation in postoperative mechanical axis and angles of femoral and tibial component position(α°, β°, and γ°) in addition to the outlier percentage of post-mechanical axis between the two groups. We used the independent sample t-test to verify our results.

Results: The deviation in angle of postoperative mechanical axis was significantly lower in the last group than the first group; 2.0633 vs. 2.6944. (p=0.0145) respectively. The deviation of α° was significantly lower in the last group than the first group; 1.1597 vs. 1.6778. (p=0.005) respectively. The deviation of β ° was lower in the last group than the first group; 1.3475 vs. 1.2115, but this value was not significant. (p=0.849). The results of the value γ° proved to be more towards extension in the first group and more towards flexion in the last group, yet these values were not significant (p=0.159). The outlier percentages of postop-mechanical axis between two groups were significantly different.

Discussion and Conclusion: The navigation system most often used in studies is an optical system with an infrared camera. Many authors have reported the efficacy of optical navigation system. It has been known to increase the accuracy of lower limb alignment and positioning of the implant while decreasing the outlier percentage of postoperative mechanical axis. The large transmitter, however, for this system requires bicortical pins, which would result in stress fracture through the drill-holes in bone. In addition, another skin incision is needed for the transmitter. A new navigation technique using electromagnetic signals has been introduced with advantages including small transmitter size, although its signal is often distorted by metal devices used in the operative field. Our hypothesis was therefore that the EM system could lead to better alignment of the leg and positioning of implants than traditional method with comparable learing curve. In summary, the EM navigation system can lead to better alignment of the mechanical axis of leg and positioning of femoral implants in coronal view compared to conventional method, although it can’t prevent outliers in all case. And also our experience suggests that in order to obtain such results, however, a certain period of learning curve may be necessary. Several valuable surgical tips specific to this technology were obtained enduring our learning curve and will be presented.