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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 39 - 39
2 May 2024
Saroha S Raheman F Jaiswal P Patel A
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In this study, we examined the impact of dual-mobility (DM) versus fixed-bearing (FB) implants on outcomes following total hip arthroplasty (THA), a common and successful operation. We examined all-cause revision, revision due to dislocation, postoperative complications and functional scores in patients undergoing primary and revision THA.

A systematic review was performed according to PRISMA guidelines, and was registered in PROSPERO (ID CRD42023403736). The Cochrane Library, Embase, MEDLINE, Web of Science, and Scopus were searched from inception to 12th March 2023. Eligible studies underwent meta-analysis and methodological assessment using the ROBINS-I tool. Data were pooled using a random-effects maximum-likelihood model.

Eight comparative, non-randomised studies involving 2,810 DM implants and 3,188 FB implants were included. In primary THA, the difference in all-cause revision was imprecise (OR 0.82, 95% CI 0.25–2.72), whilst the DM cohort had a statistically significant benefit in revision due to dislocation (OR 0.08, 95% CI 0.02–0.28). In revision THA, the DM cohort showed significant benefit in all-cause revision (OR 0.57, 95% CI 0.31–1.05) and revision due to dislocation (OR 0.14, 95% CI 0.04–0.53). DM implants were associated with a lower incidence of implant dislocation and infection. Functional outcome analysis was limited due to underreporting. No intraprosthetic dislocations were observed.

The results suggest that contemporary DM designs may be advantageous in reducing the risk of all-cause revision, revision due to dislocation, and postoperative complication incidence at mid-term follow-up. Further high-quality prospective studies are needed to evaluate the long-term performance of this design, especially in revision cases.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_13 | Pages 8 - 8
7 Aug 2023
Kaka A Shah A Yunus A Patel A Patel A
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Abstract

Introduction

Challenges in surgical training have led to the exploration of technologies such as augmented reality (AR), which present novel approaches to teaching orthopaedic procedures to medical students. The aim of this double-blinded randomised-controlled trial was to compare the validity and training effect of AR to traditional teaching on medical students’ understanding of total knee arthroplasty (TKA).

Methodology

Twenty medical students from 7 UK universities were randomised equally to either intervention or control groups. The control received a consultant-led teaching session and the intervention received training via Microsoft HoloLens, where surgeons were able to project virtual information over physical objects. Participants completed written knowledge and practical exams which were assessed by 2 orthopaedic consultants. Training superiority was established via 4 quantitative outcome measures: OSATS scores, a checklist of TKA-specific steps, procedural time, and written exam scores. Qualitative feedback was evaluated using a 5-point Likert scale.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_11 | Pages 40 - 40
7 Jun 2023
Edwards T Soussi D Gupta S Khan S Patel A Patil A Badri D Liddle A Cobb J Logishetty K
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Superior teamwork in the operating theatre is associated with improved technical performance and clinical outcomes. Yet modern rota patterns, workforce shortages, and increasing complexity of surgery, means that there is less familiarity between staff and the required choreography. Immersive Virtual Reality (iVR) can successfully train surgical staff individually, however iVR team training has yet to be investigated. We aimed to design a multiplayer iVR platform for anterior approach total hip arthroplasty (AA-THA) and assess if multiplayer iVR training was superior to single player training for acquisition of both technical and non-technical skills.

An iVR platform with choreographed roles for the surgeon and scrub nurse was developed using Cognitive Task Analysis. Forty participants were randomised to individual or team iVR training. Individually- trained participants practiced alongside virtual avatar counterparts, whilst teams trained live in pairs. Both groups underwent five iVR training sessions over 6-weeks. Subsequently, they underwent a real-life assessment in which they performed AA-THA on a high-fidelity model with real equipment in a simulated theatre. Teams performed together and individually trained participants were randomly paired up. Videos were marked by two blinded assessors recording the NOTSS, NOTECHS II and SPLINTS scores - validated technical and non-technical scores assessing surgeon and scrub nurse skills. Secondary outcomes were procedure time and number of technical errors.

Teams outperformed individually trained participants for non-technical skills in the real-world assessment (NOTSS 13.1 ± 1.5 vs 10.6 ± 1.6, p =0.002, NOTECHS-II score 51.7 ± 5.5 vs 42.3 ± 5.6, p=0.001 and SPLINTS 10 ± 1.2 vs 7.9 ± 1.6, p = 0.004). They completed the assessment 28.1% faster (27.2 minutes ± 5.5 vs 41.8 ±8.9, p<0.001), and made fewer than half the number of technical errors (10.4 ± 6.1 vs 22.6 ± 5.4, p<0.001).

Multiplayer training leads to faster surgery with fewer technical errors and the development of superior non-technical skills for anterior approach total hip arthroplasty. The convention of surgeons and nurses training separately, but undertaking real complex surgery together, can be supplanted by team training, delivered through immersive virtual reality.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_11 | Pages 18 - 18
7 Jun 2023
Schapira B Spanoudakis E Jaiswal P Patel A
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Surgical trainees are finding it increasingly more challenging to meet operative requirements and coupled with the effects of COVID-19, we face a future of insufficiently trained surgeons. As a result, virtual reality (VR) simulator training has become more prevalent and whilst more readily accepted in certain arthroscopic fields, its use in hip arthroscopy (HA) remains novel. This project aimed to validate VR high-fidelity HA simulation and assess its functional use in arthroscopic training.

Seventy-two participants were recruited to perform two basic arthroscopic tasks on a VR HA simulator, testing hip anatomy, scope manipulation and triangulation skills. They were stratified into novice (39) and experienced (33) groups based on previous arthroscopy experience. Metric parameters recorded from the simulator were used to assess construct validity. Face validity was evaluated using a Likert-style questionnaire. All recordings were reviewed by 2 HA experts for blinded ASSET score assessment.

Experienced participants were significantly faster in completing both tasks compared with novice participants (p<0.001). Experienced participants damaged the acetabular and femoral cartilage significantly less than novice participants (p=0.011) and were found to have significantly reduced path length of both camera and instrument across both tasks (p=0.001, p=0.007), demonstrating significantly greater movement economy. Total ASSET scores were significantly greater in experienced participants compared to novice participants (p=0.041) with excellent correlation between task time, cartilage damage, camera and instrument path length and corresponding ASSET score constituents. 62.5% of experienced participants reported a high degree of realism in all facets of external, technical and haptic experience with 94.4% advising further practice would improve their arthroscopic skills. There was a relative improvement of 43% in skill amongst all participants between task 1 and 2 (p<0.001).

This is the largest study to date validating the use of simulation in HA training. These results confirm significant construct and face validity, excellent agreement between objective measures and ASSET scores, significant improvement in skill with continued use and recommend VR simulation to be a valuable asset in HA training for all grades.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 13 - 13
11 Apr 2023
Edwards T Gupta S Soussi D Patel A Khan S Liddle A Cobb J Logishetty K
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Current evidence suggests that superior surgical team performance is linked to fewer intra-operative errors, reductions in mortality and even improved patient outcomes. Virtual reality has demonstrated excellent efficacy in training surgeons and scrub nurses individually, however its impact on training teams is currently unknown. This study aimed to assess if training together (scrub nurse and surgeon) in an innovative multiplayer virtual reality program was superior to single player training for novices learning anterior approach total hip arthroplasty (AA-THA).

40 participants (20 novice surgeons (CT1-ST3 level) and 20 novice scrub nurses) were enrolled in this study and randomised to individual or team virtual reality training. Individually-trained participants played with virtual avatar counterparts, whilst teams trained live in pairs (surgeon and scrub nurse). Both groups underwent 5 VR training sessions over 6 weeks. Subsequently, they underwent a real-life assessment in which they performed AA-THA on a high-fidelity model with real equipment in a simulated operating theatre. Teams performed together and individually-trained participants were randomly paired up with a solo player of the opposite role. Videos of the assessment were marked by two blinded expert assessors. The primary outcome was team performance as graded by the validated NOTECHs II score. Secondary outcomes were procedure time and number of technical errors from an expert pre-defined protocol.

Teams outperformed individually-trained participants for non-technical skills in the real-world assessment (NOTECHS-II score 50.3 ± 6.04 vs 43.90 ± 5.90, p=0.0275). They completed the assessment 28.1% faster (31.22 minutes ±2.02 vs 43.43 ±2.71, p=0.01), and made close to half the number of technical errors when compared to the individual group (12.9 ± 8.3 vs 25.6 ± 6.1, p=0.001).

Multiplayer, team training appears to lead to faster surgery with fewer technical errors and the development of superior non-technical skills.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 104 - 104
4 Apr 2023
Edwards T Khan S Patel A Gupta S Soussi D Liddle A Cobb J Logishetty K
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Evidence supporting the use of virtual reality (VR) training in orthopaedic procedures is rapidly growing. However, the impact of the timing of delivery of this training is yet to be tested. We aimed to investigate whether spaced VR training is more effective than massed VR training.

24 medical students with no hip arthroplasty experience were randomised to learning the direct anterior approach total hip arthroplasty using the same VR simulation, training either once-weekly or once-daily for four sessions. Participants underwent a baseline physical world assessment on a saw bone pelvis. The VR program recorded procedural errors, time, assistive prompts required and hand path length across four sessions. The VR and physical world assessments were repeated at one-week, one-month, and 3 months after the last training session.

Baseline characteristics between the groups were comparable (p > 0.05). The daily group demonstrated faster skills acquisition, reducing the median ± IQR number of procedural errors from 68 ± 67.05 (session one) to 7 ± 9.75 (session four), compared to the weekly group's improvement from 63 ± 27 (session one) to 13 ± 15.75 (session four), p < 0.001. The weekly group error count plateaued remaining at 14 ± 6.75 at one-week, 16.50 ± 16.25 at one-month and 26.45 ± 22 at 3-months, p < 0.05. However, the daily group showed poorer retention with error counts rising to 16 ± 12.25 at one-week, 17.50 ± 23 at one-month and 41.45 ± 26 at 3-months, p<0.01. A similar effect was noted for the number of assistive prompts required, procedural time and hand path length. In the real-world assessment, both groups significantly improved their acetabular component positioning accuracy, and these improvements were equally maintained (p<0.01).

Daily VR training facilitates faster skills acquisition; however weekly practice has superior skills retention.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 90 - 90
4 Apr 2023
Sharma M Khanal P Patel N Patel A
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To investigate the utility of virtual reality (VR) simulators in improving surgical proficiency in Orthopaedic trainees for complex procedures and techniques.

Fifteen specialty surgeons attending a London Orthopaedic training course were randomised to either the VR (n = 7) or control group (n = 8). All participants were provided a study pack comprising an application manual and instructional video for the Trochanteric Femoral Nail Advanced (TFNA) procedure. The VR group underwent additional training for TFNA using the DePuy Synthes (Johnson and Johnson) VR simulator. All surgeons were then observed applying the TFNA in a Sawbones model and assessed by a blinded senior consultant using three metrics: time to completion, 22-item procedure checklist and 5-point global assessment scale.

Participant demographics for the VR and control groups were similar in context of age (mean [SD]: VR group, 31.0 [2.38] years; control group, 30.6 [2.39] years), gender (VR group, 5 [71%] men; control group, 8 [100%] men) and prior experience with TFNA (had applied TFNA as primary surgeon: VR group, 6 [86%]; control group, 7 [88%]). Although statistical significance was not reached, the VR group, on average, outperformed the control group on all three metrics. They completed the TFNA procedure faster (mean [SD]: 18.2 [2.16] minutes versus 19.78 [1.32] minutes; p<0.189), performed a greater percentage of steps correctly (79% versus 66%; p<0.189) and scored a higher percentage on the global assessment scale (75% versus 65%; p<0.232).

VR simulators offer a safe and accessible means for Orthopaedic trainees to prepare for and supplement their theatre-based experience. It is vital, therefore, to review and validate novel simulation-based systems and in turn facilitate their improvement. We intend to increase our sample size and expand this preliminary study through a second upcoming surgical course for Orthopaedic trainees in London.


Bone & Joint Open
Vol. 4, Issue 3 | Pages 129 - 137
1 Mar 2023
Patel A Edwards TC Jones G Liddle AD Cobb J Garner A

Aims

The metabolic equivalent of task (MET) score examines patient performance in relation to energy expenditure before and after knee arthroplasty. This study assesses its use in a knee arthroplasty population in comparison with the widely used Oxford Knee Score (OKS) and EuroQol five-dimension index (EQ-5D), which are reported to be limited by ceiling effects.

Methods

A total of 116 patients with OKS, EQ-5D, and MET scores before, and at least six months following, unilateral primary knee arthroplasty were identified from a database. Procedures were performed by a single surgeon between 2014 and 2019 consecutively. Scores were analyzed for normality, skewness, kurtosis, and the presence of ceiling/floor effects. Concurrent validity between the MET score, OKS, and EQ-5D was assessed using Spearman’s rank.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_16 | Pages 9 - 9
1 Dec 2021
Edwards T Soussi D Gupta S Patel A Liddle A Khan S Cobb J Logishetty K
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Abstract

Objectives

Non-technical skills including teamwork play a pivotal role in surgical outcomes. Virtual reality is effective at improving technical skills, however there is a paucity of evidence on team-based virtual reality (VR) training. This study aimed to assess if multiplayer virtual reality training was superior to solo training for acquisition of both technical and non-technical skills in learning the complex anterior approach total hip arthroplasty operation.

Methods

10 novice surgeons and 10 novice scrub nurses, were randomised to solo or team virtual reality training to perform anterior approach total hip arthroplasty. Solo participants trained with virtual avatar counterparts, whilst teams trained in pairs (surgeon and scrub nurse). Both groups underwent 5 VR training sessions over 6 weeks. Then, they underwent a real-life assessment in which they performed AA-THA on a high-fidelity model with real equipment in a simulated operating theatre. Teams performed together and solo participants were randomly paired up with a solo player of the opposite role. Videos of the assessment were marked by two blinded expert assessors. Outcomes were procedure time, procedural errors from an expert pre-defined protocol and acetabular component positioning. Non-technical skills were assessed using the NOTECHs II and NOTSS scores.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_16 | Pages 32 - 32
1 Dec 2021
Edwards T Khan S Patel A Gupta S Soussi D Liddle A Cobb J Logishetty K
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Abstract

Objectives

Evidence supporting the use of immersive virtual reality (iVR) training in orthopaedic procedures is rapidly growing. However, the impact of the timing of delivery of this training is yet to be tested. This study investigated whether spaced iVR training is more effective than massed iVR training for novices learning hip arthroplasty.

Methods

24 medical students with no hip arthroplasty experience were randomised to learning total hip arthroplasty using the same iVR simulation training either once-weekly or once-daily for four sessions. Participants underwent a baseline physical world assessment to orientate an acetabular component on a saw bone pelvis, and a baseline knowledge test. In iVR, we recorded procedural errors, time, numbers of prompts required and path lengths of the hands and head across 4 sessions. To assess skill retention, the iVR and baseline physical world assessments were repeated at one-week and one-month.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_1 | Pages 44 - 44
1 Feb 2021
Edwards T Patel A Szyszka B Coombs A Kucheria R Cobb J Logishetty K
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Background

Revision total knee arthroplasty (rTKA) is a high stakes procedure with complex equipment and multiple steps. For rTKA using the ATTUNE system revising femoral and tibial components with sleeves and stems, there are over 240 pieces of equipment that require correct assembly at the appropriate time. Due to changing teams, work rotas, and the infrequency of rTKR, scrub nurses may encounter these operations infrequently and often rely heavily on company representatives to guide them. In turn, this delays and interrupts surgical efficiency and can result in error. This study investigates the impact of a fully immersive virtual reality (VR) curriculum on training scrub nurses in technical skills and knowledge of performing a complex rTKA, to improve efficiency and reduce error.

Method

Ten orthopaedic scrub nurses were recruited and trained in four VR sessions over a 4-week period. Each VR session involved a guided mode, where participants were taught the steps of rTKA surgery by the simulator in a simulated operating theatre. The latter 3 sessions involved a guided mode followed by an unguided VR assessment. Outcome measures in the unguided assessment were related to procedural sequence, duration of surgery and efficiency of movement. Transfer of skills was assessed during a pre-training and post-training assessment, where participants completed multi-step instrument selection and assembly using the real equipment. A pre and post-training questionnaire assessed the participants knowledge, confidence and anxiety.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_4 | Pages 94 - 94
1 Apr 2018
Patel A Li L Qureshi A Deierl K
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Introduction

Hoffa fractures are rare, intra-articular fractures of the femoral condyle in the coronal plane and involving the weight-bearing surface of the distal femur. Surgical fixation is warranted to achieve stability, early mobilisation and satisfactory knee function.

We describe a unique type of Hoffa fracture in the coronal plane with sagittal split and intra-articular comminution. There is scant evidence in current literature with regards to surgical approaches, techniques and implants. We report of our case with a review of the literature.

Case report

A 40 year old male motorcyclist was involved in a high speed road traffic collision. X-rays confirmed displaced unicondylar fracture of the lateral femoral condyle. CT showed sagittal split of the Hoffa fragment and intra-articular comminution. MRI showed partial rupture of the anterior cruciate ligament. The patient underwent definitive surgical treatment via a midline skin incision and lateral parapatellar approach using cannulated screws, headless compression screws and anti-glide plate. Weightbearing was commenced at 8 weeks. Arthroscopy and adhesiolysis was performed at 12 weeks to improve range of motion. The patient was discharged at one year with a pain-free, functional knee.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_8 | Pages 26 - 26
1 Apr 2017
Li L Patel A Jundi H Parmar H
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Background

Focal resurfacing can treat localised articular damage of the knee not appropriate for arthroplasty or biological repair. Independent results on these implants are limited. We previously published early results showing significantly improved Knee Injury & Osteoarthritis Outcome Score (KOOS4) without complication or re-operation, demonstrating this system gives good analgesia and functional improvement in selected patients. We present long-term follow-up of these patients.

Methods

We prospectively evaluated medium- to long-term results in patients with localised, full-thickness articular cartilage defects of the knee undergoing HemiCAP resurfacing. All procedures were performed by one consultant surgeon. Post-operative rehabilitation was standardised. Outcome measures were KOOS4 score, visual analogue score (VAS), Kellgren and Lawrence arthritis grade, and re-operation rates.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_8 | Pages 65 - 65
1 Apr 2017
Patel A Li L Rashid A
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Background

Radial head fractures are the commonest fractures involving the elbow. The goals of treatment are to restore stability, preserve motion, and maintain the relative length of the radius. Fortunately, most simple uncomplicated fractures can be treated non-operatively. Choosing between fixation and radial head replacement for comminuted fractures remains difficult. Excision of radial head fractures is not an ideal option in unstable elbow injuries. The purpose of this systematic review was to search for and critically appraise articles directly comparing functional outcomes and complications for fixation (open reduction internal fixation, ORIF) versus arthroplasty for comminuted radial head fractures (Mason type 3) in adults.

Method

A comprehensive search of Medline, Embase and Cochrane databases using specific search terms and limits was conducted. Strict eligibility criteria were applied to stringently screen resultant articles. Three comparative studies were identified and reviewed.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_1 | Pages 75 - 75
1 Jan 2017
Anand A Li L Trigkilidas D Patel A
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We performed a systematic review to compare outcomes of cemented versus uncemented trapezio-metacarpal joint (TMCJ) replacement for treatment of base-of-thumb arthritis.

We assessed improvements in pain and function, range of movement (ROM), strength, complications and need for revision surgery. A thorough literature search was performed. A total of 481 studies were identified from the literature search (179 Medline, 253 Embase, 27 CINAHL, 22 Cochrane). Of 43 relevant titles 28 were selected for full-text review after assessment of the abstracts. Duplicate studies were removed. 18 studies met inclusion criteria on full-text review. All studies were of level IV evidence. There were no randomised controlled trials or meta-analyses. The studies were critically appraised using a validated scoring system.

Most studies reported good outcomes for pain and strength, and functional outcome was comparable for both groups. ROM was generally improved for both prosthetic types, however statistical calculation was lacking in many studies. Trapezial component loosening was the main problem for both cemented and uncemented prostheses, however radiological loosening did not necessarily correlate with implant failure.

This systematic review has found that both cemented and uncemented replacements generally give good outcomes for the treatment of TMCJ arthritis, however young, male, patients with manual occupations and with disease in the dominant hand and patients with poor trapezial bone stock appear to be at higher risk for implant failure due to cup loosening. We recommend the construction of a joint registry to record implantation and revision rates.


The Bone & Joint Journal
Vol. 98-B, Issue 9 | Pages 1234 - 1239
1 Sep 2016
Yu HM Malhotra K Butler JS Patel A Sewell MD Li YZ Molloy S

Aims

Patients with multiple myeloma (MM) develop deposits in the spine which may lead to vertebral compression fractures (VCFs). Our aim was to establish which spinopelvic parameters are associated with the greatest disability in patients with spinal myeloma and VCFs.

Patients and Methods

We performed a retrospective cross-sectional review of 148 consecutive patients (87 male, 61 female) with spinal myeloma and analysed correlations between spinopelvic parameters and patient-reported outcome scores. The mean age of the patients was 65.5 years (37 to 91) and the mean number of vertebrae involved was 3.7 (1 to 15).


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 14 - 14
1 May 2016
Manalo J Patel A Goyal N Fitz D Talati R Stulberg S
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Introduction

Three anatomic landmarks are typically used to estimate proper femoral component rotation in total knee arthroplasty: the transepicondylar axis (TEA), Whiteside's line, and the posterior condylar axis (PCA). Previous studies have shown that the presence of tibia vara may be accompanied by a hyperplastic posteromedial femoral condyle, which affects the relationship between the PCA and the TEA. The purpose of this study was to determine the relationship of tibia vara with the PCA.

Methods

Two hundred and forty-eight knees underwent planning for total knee arthroplasty with MRI. The MRI was used to characterize the relationship between the transepicondylar axis and the posterior condylar axis. Long-leg standing films (LLSF) were obtained to evaluate the medial proximal tibial angle. The MPTA is defined as the medial angle formed between a line along the anatomic axis of the tibia and a line along the tibial plateau.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 27 - 27
1 May 2016
Carroll K Patel A Carli A Cross M Jerabek S Mayman D
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Introduction

While implant designs and surgical techniques have improved in total knee arthroplasty (TKA), approximately 20% of patients remain dissatisfied. The purpose of this study was to determine if reproduction of anatomic preoperative measurements correlated to improved clinical outcomes in TKA.

Methods

We retrospectively reviewed95 patients (106 knees) who underwent a TKA between 2012 −2013 with a minimum of one year follow-up. All patients had a pre and post-operative SF-12 and WOMAC scores. Pre and 6 week post-operative radiographs were reviewed to compare restoration of coronal plane alignment, maintenance of joint line obliquity, and maintenance of tibial varus. Coronal alignment was defined as the angle formed between the mechanical axis of the femur and the the tibia. Joint line obliquity was defined as the angle between the mechanical axis of the limb and the line which best parallels the joint space at the knee. Tibial varus was compared between the preoperative proximal lateral tibial angle and the angle formed by the mechanical axis of the tibia and tibial component postoperatively.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 13 - 13
1 May 2016
Manalo J Patel A Goyal N Fitz D Talati R Stulberg S
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Introduction

Current techniques in total knee arthroplasty aim to restore the coronal mechanical axis to neutral. Preoperative planning has historically been based on long-leg standing films (LLSF) which allow surgeons to plan bony resection and soft tissue releases. However, LSSF can be prone to error if malrotated. Recently, patient-specific guides (PSG) utilizing supine magnetic resonance imaging (sMRI) have become an accepted technique for preoperative planning. In this study we sought to compare the degree of coronal deformity using LLSF and sMRI.

Methods

Two hundred thirty knees underwent planning for total knee arthroplasty with sMRI and LLSF. Coronal plane deformity was determined based on the femoral-tibial angle (FTA) as defined by the angle formed between a line from the center of the femoral head to the intercondylar notch and a line from the middle of the tibial spines to the middle of the ankle joint. Mechanical axis values from the sMRI were compared with values obtained from LLSF


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 53 - 53
1 Jan 2016
Talati R Alvi H Sweeney P Patel A Stulberg SD
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Introduction

Total knee arthroplasty is effective for the management of osteoarthritis of the knee. Conventional techniques utilizing manual instrumentation (MI) make use of intramedullary femoral guides and either extramedullary or intramedullary tibial guides. While MI techniques can achieve excellent results in the majority of patients, those with ipsilateral hardware, post-traumatic deformity or abnormal anatomy may be technically more challenging, resulting in poorer outcomes. Computer-assisted navigation (CAN) is an alternative that utilizes fixed trackers and anatomic registration points, foregoing the need for intramedullary guides. This technique has been shown to yield excellent results including superior alignment outcomes compared to MI with fewer outliers. However, studies report a high learning curve, increased expenses and increased operative times. As a result, few surgeons are trained and comfortable utilizing CAN. Patient-specific instrumentation is an alternative innovation for total knee arthroplasty. Custom guide blocks are fabricated based on a patient's unique anatomy, allowing for the benefits of CAN but without the increased operative times or the high learning curve. In this study we sought to evaluate the accuracy of PSI techniques in patients with previous ipsilateral hardware of the femur.

Methods

After reviewing our database of 300 PSI total knee arthroplasty patients, 16 were identified (10 male, 6 female) using the Zimmer NexGen Patient Specific Instrumentation System. Fourteen patients included in the study had a preexisting total hip arthroplasty on the ipsilateral side [Figure 1], 1 had a sliding hip screw, and 1 patient had a cephalomedullary nail. Postoperative mechanical axis alignment measurements were performed using plain long-standing radiographs [Figure 2]. The American Knee Society Score was used to evaluate clinical outcomes postoperatively.