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Bone & Joint Open
Vol. 3, Issue 7 | Pages 589 - 595
1 Jul 2022
Joo PY Chen AF Richards J Law TY Taylor K Marchand K Clark G Collopy D Marchand RC Roche M Mont MA Malkani AL

Aims

The aim of this study was to report patient and clinical outcomes following robotic-assisted total knee arthroplasty (RA-TKA) at multiple institutions with a minimum two-year follow-up.

Methods

This was a multicentre registry study from October 2016 to June 2021 that included 861 primary RA-TKA patients who completed at least one pre- and postoperative patient-reported outcome measure (PROM) questionnaire, including Forgotten Joint Score (FJS), Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement (KOOS JR), and pain out of 100 points. The mean age was 67 years (35 to 86), 452 were male (53%), mean BMI was 31.5 kg/m2 (19 to 58), and 553 (64%) cemented and 308 (36%) cementless implants.


Bone & Joint Open
Vol. 3, Issue 5 | Pages 383 - 389
1 May 2022
Motesharei A Batailler C De Massari D Vincent G Chen AF Lustig S

Aims

No predictive model has been published to forecast operating time for total knee arthroplasty (TKA). The aims of this study were to design and validate a predictive model to estimate operating time for robotic-assisted TKA based on demographic data, and evaluate the added predictive power of CT scan-based predictors and their impact on the accuracy of the predictive model.

Methods

A retrospective study was conducted on 1,061 TKAs performed from January 2016 to December 2019 with an image-based robotic-assisted system. Demographic data included age, sex, height, and weight. The femoral and tibial mechanical axis and the osteophyte volume were calculated from CT scans. These inputs were used to develop a predictive model aimed to predict operating time based on demographic data only, and demographic and 3D patient anatomy data.


Bone & Joint Open
Vol. 2, Issue 11 | Pages 932 - 939
12 Nov 2021
Mir H Downes K Chen AF Grewal R Kelly DM Lee MJ Leucht P Dulai SK

Aims

Physician burnout and its consequences have been recognized as increasingly prevalent and important issues for both organizations and individuals involved in healthcare delivery. The purpose of this study was to describe and compare the patterns of self-reported wellness in orthopaedic surgeons and trainees from multiple nations with varying health systems.

Methods

A cross-sectional survey of 774 orthopaedic surgeons and trainees in five countries (Australia, Canada, New Zealand, UK, and USA) was conducted in 2019. Respondents were asked to complete the Mayo Clinic Well-Being Index and the Stanford Professional Fulfillment Index in addition to 31 personal/demographic questions and 27 employment-related questions via an anonymous online survey.


The Bone & Joint Journal
Vol. 103-B, Issue 1 | Pages 16 - 17
1 Jan 2021
McNally M Sousa R Wouthuyzen-Bakker M Chen AF Soriano A Vogely HC Clauss M Higuera CA Trebše R


The Bone & Joint Journal
Vol. 103-B, Issue 1 | Pages 18 - 25
1 Jan 2021
McNally M Sousa R Wouthuyzen-Bakker M Chen AF Soriano A Vogely HC Clauss M Higuera CA Trebše R

Aims

The diagnosis of periprosthetic joint infection (PJI) can be difficult. All current diagnostic tests have problems with accuracy and interpretation of results. Many new tests have been proposed, but there is no consensus on the place of many of these in the diagnostic pathway. Previous attempts to develop a definition of PJI have not been universally accepted and there remains no reference standard definition.

Methods

This paper reports the outcome of a project developed by the European Bone and Joint Infection Society (EBJIS), and supported by the Musculoskeletal Infection Society (MSIS) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Implant-Associated Infections (ESGIAI). It comprised a comprehensive review of the literature, open discussion with Society members and conference delegates, and an expert panel assessment of the results to produce the final guidance.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 5 - 5
1 Oct 2020
Gorman H Jordan E Varady NH Hosseinzadeh S Smith S Chen AF Mont M Iorio R
Full Access

Introduction

A staging system has been developed to revise the 1994 ARCO classification for ONFH. The final consensus resulted in the following 4-staged system: stage I—X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II—X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III—fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV—X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. Radiographs, magnetic resonance imaging (MRI), and computed tomography (CT) scans may all be involved in diagnosing ONFH; however, the optimal diagnostic modality remains unclear. The purpose of this study was to identify: 1) how ONFH is diagnosed at a single academic medical center, and 2) if CT is a necessary modality for diagnosing/staging OFNH.

Methods

The EMR was queried for the diagnosis of ONFH between 1/1/2008–12/31/2018 at a single academic medical center. CT and MRI scans were reviewed by the senior author and other contributors. The timing and staging quality of the diagnosis of ONFH were compared between MRI and CT to determine if CT was a necessary component of the ONFH work-up.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 33 - 33
1 Oct 2020
Hamilton WG Loper NR Chen AF Abdel MP Springer BD
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Background

The COVID-19 pandemic caused an abrupt disruption in fellowship training, with most in-person teaching ceasing in mid-March 2020. An online lecture series was quickly initiated named the Fellows Online COVID-19 AAHKS Learning (FOCAL) initiative. This study will summarize the results of that initiative.

Methods

Beginning March 31, 2020, an online teaching program was initiated. Adult reconstruction fellows and senior residents with interest in adult reconstruction were invited to participate in the free, live, online education sessions. Faculty from well-respected training institutions from around the country volunteered their time to host the initiative, choosing topics to present, ranging from hip (13 lectures) and knee (9), to practice management/miscellaneous (12). All sessions were recorded and posted on the society website for viewing. Attendee registrations were tracked via the online platform and the maximum number of attendees per session was recorded. A survey was administered to attendees for feedback.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_11 | Pages 9 - 9
1 Oct 2019
Kinsey T Chen AF Hozack WJ Mont MA Orozco F Mahoney OM
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Introduction

Component position and overall limb alignment following total knee arthroplasty (TKA) have been shown to influence prosthetic survivorship and clinical outcomes1. The objective of this study was to compare the accuracy to plan of three-dimensional modeled (3D) TKA with manual TKA for component alignment and position.

Methods

An open-label prospective clinical study was conducted to compare 3D modeling with manual TKA (non-randomized) at 4 U.S. centers between July 2016 and August 2018. Men and women aged > 18 with body mass index < 40kg/m2 scheduled for unilateral primary TKA were recruited for the study. 144 3DTKA and 86 manual TKA (230 patients) were included in the analysis of accuracy outcomes. Seven high-volume, arthroplasty fellowship-trained surgeons performed the surgeries. The surgeon targeted a neutral (0°) mechanical axis for all except 9 patients (4%) for whom the target was within 0°±3°. Computed tomography (CT) scans obtained approximately 6 weeks post-operatively were analyzed using anatomical landmarks to determine femoral and tibial component varus/valgus position, femoral component internal/external rotation, and tibial component posterior slope. Absolute deviation from surgical plan was defined as the absolute value of the difference between the CT measurement and the surgeon's operative plan. Smaller absolute deviation from plan indicated greater accuracy. Mean component positions for manual and 3DTKA groups were compared using two-sample t tests for unequal variances. Differences of absolute deviations from plan were compared using stratified Wilcoxon tests, which controlled for study center and accounted for skewed distributions of the absolute values. Alpha was 0.05 two-sided. At the time of this report, CT measurements of femoral component rotation position referenced from the posterior condylar axis were not yet completed; therefore, the current analysis of femoral component rotation accuracy to plan reflects one center that exclusively used manual instruments referencing the transepicondylar axis (TEA).


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_11 | Pages 37 - 37
1 Oct 2019
Nahhas CR Chalmers PN Parvizi J Sporer SM Berend KR Moric M Chen AF Austin M Deirmengian GK Morris MJ Culvern C Valle CJD
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Background

The purpose of this multi-center, randomized clinical trial was to compare static and articulating spacers in the treatment of PJI complicating total knee arthroplasty TKA.

Methods

68 Patients treated with two-stage exchange arthroplasty were randomized to either a static (32 patients) or an articulating (36 patients) spacer. A power analysis determined that 28 patients per group were necessary to detect a 13º difference in range of motion between groups. Six patients were excluded after randomization, six died, and seven were lost to follow-up prior to two years.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_12 | Pages 21 - 21
1 Oct 2019
Huddleston JI Chen AF Browne JA Jaffri H Weitzman DS Bozic KJ
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Introduction

Meaningful clinical improvement as demonstrated through patient-reported outcome measures (PROMs) are increasingly used to evaluate success of total hip arthroplasty (THA) procedures. This patient perspective can provide a full picture when used with clinical data to best evaluate surgical outcomes.

Methods

All primary THA procedures reported to the American Joint Replacement Registry from 2012–2018 with linked pre-operative and 1-year post-operative functional or anatomical PROMs were included. The achievement of minimal clinically-important difference (MCID) was calculated using the distribution method. Logistic regression models with covariate adjustment for patient demographics, American Society of Anesthesiologists (ASA) score, and body mass index (BMI) were constructed to identify associations with PROMs. Results were analyzed based on hospital size (small, medium and large) and teaching type (non-teaching, minor and major) based on the American Hospital Association Survey (2015).


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 69 - 69
1 Apr 2019
Blevins K Danoff J Goel R Foltz C Chen AF Hozack W
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Introduction

The purpose of this study is to compare total and rate of caloric energy expenditure between conventional and robotic-arm assisted total knee arthroplasty (TKA) between a high volume “veteran” surgeon (HV) and a lower volume, less experienced surgeon (LV).

Methods

Two specialized arthroplasty surgeons wore a biometric-enabled shirt and energy expenditure outcomes were measured (total caloric expenditure, kilocalories per minute, heart rate variability, and surgical duration) during 35 conventional (CTKA) and 29 robotic primary total knee arthroplasty (RTKA) procedures.


The Bone & Joint Journal
Vol. 101-B, Issue 2 | Pages 221 - 226
1 Feb 2019
Ryan SP DiLallo M Klement MR Luzzi AJ Chen AF Seyler TM

Aims

The aim of this study was to characterize the factors leading to transfemoral amputation after total knee arthroplasty (TKA), as well as the rates of mortality and functional independence after this procedure in these patients.

Patients and Methods

This was a multicentre retrospective review with a prospective telephone survey for the assessment of function. All patients with a TKA who subsequently required transfemoral amputation between January 2001 and December 2015 were included. Demographic information, medical comorbidities, and postoperative mortality data were collected. A 19-item survey was used for the assessment of function in surviving patients.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_12 | Pages 67 - 67
1 Oct 2018
Ryan SP Dilallo M Luzzi AJ Klement MR Chen AF Jiranek WA Seyler TM
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Introduction

Total Knee Arthroplasty (TKA) in high risk patients may result in numerous post-operative complications that may ultimately lead to above knee amputation (AKA). There is a paucity of literature regarding AKA in patients with prior TKA. We sought to characterize the factors leading to AKA, as well as patient functional and clinical outcomes post-operatively, with the hypothesis that minimal activity would be achieved.

Methods

This is a multicenter retrospective review for patient identification, with prospective telephone survey completion for assessment of functional status. All patients from January 2001 to December 2015 with AKA and prior TKA at two academic centers were included for possible survey enrollment. Demographic information and medical comorbidities were collected, in addition to perioperative and post-operative mortality data. A 23-item survey was provided to all available patients and analyzed for patient functional status.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_13 | Pages 60 - 60
1 Oct 2018
Fleischman AN Tarabichi M Makar G Foltz C Hozack WJ Austin MS Chen AF
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Background

Orthopedic surgeons have relied heavily on opiates after total hip replacement (THR) despite no clear evidence of benefit and a rapidly growing abuse epidemic. Multimodal analgesia may reduce or even obviate the need for opiates after elective surgery.

Methods

In a cluster-randomized, crossover trial, 235 patients undergoing THR were assigned to receive multimodal analgesia with minimal opiates (Group A-10 tablets), multimodal analgesia with a full opiate supply (Group B-60 tablets), or a traditional opiate regimen without multimodal analgesia (Group C-60 tablets). The multimodal regimen comprised scheduled-dose acetaminophen, meloxicam, and gabapentin. Primary outcomes were daily pain and opiate utilization for the first 30-days. Secondary outcomes included assessments of satisfaction, sleep-quality, opiate-related symptoms, hip function, and adverse events.


The Bone & Joint Journal
Vol. 95-B, Issue 11 | Pages 1450 - 1452
1 Nov 2013
Parvizi J Gehrke T Chen AF

Louis Pasteur once said that: “Fortune favours the prepared mind.” As one of the great scientists who contributed to the fight against infection, he emphasised the importance of being prepared at all times to recognise infection and deal with it. Despite the many scientific discoveries and technological advances, such as the advent of antibiotics and the use of sterile techniques, infection continues to be a problem that haunts orthopaedic surgeons and inflicts suffering on patients.

The medical community has implemented many practices with the intention of preventing infection and treating it effectively when it occurs. Although high-level evidence may support some of these practices, many are based on little to no scientific foundation. Thus, around the world, there is great variation in practices for the prevention and management of periprosthetic joint infection.

This paper summaries the instigation, conduct and findings of a recent International Consensus Meeting on Surgical Site and Periprosthetic Joint Infection.

Cite this article: Bone Joint J 2013;95-B:1450–2.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 11 | Pages 1448 - 1453
1 Nov 2006
Chen AF Alan RK Redziniak DE Tria AJ

The aim of this study was to compare the results in patients having a quadriceps sparing total knee replacement (TKR) with those undergoing a standard TKR at a minimum follow-up of two years.

All patients who had a TKR with a high-flex posterior-stabilised prosthesis prior to December 2002 were reviewed retrospectively. There were 57 patients available for follow-up. Those with a quadriceps sparing TKR had less pain peri-operatively with a greater degree of flexion at all the post-operative visits and at the final follow-up, but their operations took longer, with less accurate radiological alignment. There was no difference in the complications and in the Knee Society scores between the two groups at the final follow-up.

Total knee replacement through a quadriceps sparing approach has some peri-operative advantages over the standard incision. At a minimum follow-up of two years the clinical results were similar to those with a standard incision, but the radiological outcomes of the quadriceps sparing group were inferior.