Introduction

The postoperative inflammatory response may be implicated in the aetiology of patient dissatisfaction following Total Knee Arthroplasty. Robotic-arm assisted TKA has been associated with reduced bone and soft tissue trauma. The objective of this Randomised Controlled Trial was to compare the inflammatory response in conventional Jig-based versus robotic arm-assisted TKA and examine the relationship with patient reported outcome measures and functional outcomes.

Methodology

30 patients with knee osteoarthritis were randomised to either conventional or robotic-arm assisted TKA. Blood samples were collected for up to 28 days post-operatively and intraarticular drain samples at 6 and 24 hours, to ascertain the systemic and local inflammatory responses. The Spearman's correlation was utilised to evaluate the relationship with PROMs and functional outcomes.

Introduction

Autologous chondrocyte implantation (ACI) is a common procedure, primarily performed in active, young patients to treat knee pain and functional limitations resulting from cartilage injury. Nevertheless, the functional outcomes of ACI remain poorly understood. Thus, the aim of this systematic review was to evaluate the biomechanical outcomes of ACI.

Methodology

Ovid MEDLINE, Embase, and Web of Science were systematically searched using the terms ‘Knee OR Knee joint AND Autologous chondrocyte implantation OR ACI’. Strict inclusion and exclusion criteria were used to screen publications by title, abstract, and full text. Study quality and bias were assessed by two reviewers. PROSPERO ID: CRD42021238768.

Introduction

The demand for total knee arthroplasty (TKA) in older patients is increasing. Current perceptions regarding risks may result in patients inappropriately being denied surgery. This study aimed to evaluate TKA outcomes in patients aged ≥80 compared to a younger cohort.

Methodology

This study retrospectively analysed prospectively collected data from the Scottish Arthroplasty Project. Data were extracted for all patients undergoing primary TKA between 2000 and 2019 in two age groups: 1) ≥80 and 2) 50–79. Hybrid and partial knee replacements and those with incomplete data were excluded. Data were extracted on post-operative complications, infection within 1 year, mortality and revision at any point.

Introduction

The paediatric population present unique challenges to the knee surgeon, particularly when treating recurrent patellofemoral instability(PFI), the management of which is poorly standardised. Through the EPPIC BASK National Trainee Collaborative, we aimed to identify which procedures (and in which combination) are being used to surgically manage recurrent PFI in skeletally immature patients across the UK.

Methods

A retrospective national service evaluation via a trainee collaborative analysing local trust data between 1st January 2014 and 31st December 2019. Data from institutions registered for EPPIC was compiled and compared to the national guidelines for adults.

Background

The incidence of periprosthetic fractures of the femur around a total knee arthroplasty (TKA) is rising and this is owed to the increased longevity that today's TKA implants allow for, as well as an aging population. These injuries are significant as they are related to increased morbidity and mortality.

Methods

We retrospectively reviewed all periprosthetic fractures around a TKA that presented to our NHS Trust between 2011 to 2020. Medical records were reviewed. Treatment, complications and mortality were noted.

Introduction

There is a longstanding presumed association between obesity, complications, and revision surgery in primary knee arthroplasty. This has more recently been called into question, particularly in centres where a high volume of arthroplasty is performed. We investigated the correlation between Body Mass Index (BMI), mortality, and revision surgery.

Method

This was a cohort study of at least 10 years following primary knee arthroplasty from a single high volume arthroplasty unit. Mortality and revision rates were collected from all patients who underwent primary knee arthroplasty between 2009 and 2010. Kaplan Meier analysis was performed.

Objectives

To determine the effectiveness of LIA compared to ACB in providing pain relief and reducing opiates usage in hamstring graft ACL reconstructions.

Materials and Methods

In a consecutive series of hamstring graft ACL reconstructions, patients received three different regional and/or anaesthetic techniques for pain relief. Three groups were studied: group 1: general anaesthetic (GA)+ ACB (n=38); group 2: GA + ACB + LIA (n=31) and group 3: GA+LIA (n=36). ACB was given under ultrasound guidance. LIA involved infiltration at skin incision site, capsule, periosteum and in the hamstring harvest tunnel. Analgesic medications were similar between the three groups as per standard multimodal analgesia (MMA). Patients were similar in demographics distribution and surgical technique. The postoperative pain and total morphine requirements were evaluated and recorded. The postoperative pain was assessed using the visual analogue scores (VAS) at 0hrs, 2hrs, 4hrs, weight bearing (WB) and discharge (DC).

Introduction

Derby technique for posterolateral corner (PLC) reconstruction uses a doubled gracilis autograft to reconstruct the popliteo-fibular ligament (PFL) and a split biceps tendon transfer to reconstruct the lateral collateral ligament (LCL). We report midterm outcomes of a case series who underwent PLC reconstruction.

Methodology

A retrospective review of 27 patients who underwent PLC reconstruction from 2012 until 2018 was performed (6 females, 21 males, median age 26). Median time interval from injury to primary procedure was 10 months. Outcomes were recorded as per clinical assessment and outcome scores.

Purpose

Recently several authors have suggested a correlation between posterior tibial slope (PTS) and sagittal stability of the knee. However, there is a lack of consensus in the literature relating to measurement, normal values and important values to guide treatment. We performed a systematic literature review looking at PTS and cruciate ligament surgery. Our aim was to define a gold standard measurement technique, determine normal ranges and important values for consideration during cruciate ligament surgery.

Methods

Electronic searches of MEDLINE (PubMed), CINAHL, Cochrane, Embase, ScienceDirect, and NICE in June 2020 were completed. Inclusion criteria were original studies in peer-reviewed English language journals. A quality assessment of included studies was completed using the Methodological Index for Non-Randomized Studies (MINORS) Criteria.

Background

Around 5–15% of patients will experience chronic postoperative pain after total knee replacement (TKR) surgery but the source of the pain is unknown. The aim of this study was to assesses patients six months after TKR using magnetic resonance imaging (MRI) of the knee, pain sensory profiles and assessments of pain catastrophizing thoughts.

Methods

Forty-six patients had complete postoperative data and were included. MRI findings were scored according to the MRI Osteoarthritis Knee Score (MOAKS) recommendation for Hoffa synovitis, effusion size and bone marrow lesions. Pain sensory profiles included the assessment of pressure pain thresholds (PPTs), temporal summation of pain (TSP) and conditioned pain modulation (CPM). Pain catastrophizing was assessed using the pain catastrophizing scale (PCS). Clinical pain was evaluated using a visual analog scale (VAS, 0–10cm) and groups of moderate-to-severe (VAS>3) and non-to-mild postoperative pain (VAS≤3) were identified.

Introduction

Traumatic knee dislocations are devastating injuries and there is no single best accepted treatment. This study looked at functional outcome of a single surgeon case series of patients who underwent surgical management of their knee dislocation.

Methods

Eighty-seven patients with knee dislocation were treated at a major trauma centre. Acute surgical repair and reconstruction with fracture fixation within 4 weeks was preferred unless the patient was too unstable (Injury severity score>16). The collaterals were repaired and augmented using a variety of autografts, allografts or synthetic grafts. PCL was primarily braced and reconstructed subsequently, if required. Outcome was collected prospectively using IKDC score, KOOS and Tegner score.

Methods

15 patients post TKA with severe arthrofibrosis and mean ROM 71° were recruited, (three cases had previously failed manipulation under anaesthetic (MUA). Patients received 8 weeks standard physiotherapy, then treatment with the STAK at home for 8 weeks. ROM, extension, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford Knee Scores (OKS) were collected at various time-points.

Results

Following standard physiotherapy there were small improvements in ROM (8°) (p<0.01), but no significant improvements in extension, OKS or WOMAC (p=0.39). Following the STAK treatment all outcomes significantly improved (p<0.01). STAK group; mean ROM (21° versus 8°, p < 0.001), extension 9° versus 2° (p < 0.01), WOMAC (18 points versus 3, p < 0.01), and OKS (8 points versus 4, p<0.01). No patients suffered any complications relating to the STAK.

INTRODUCTION

A paucity of literature exists regarding efficacy of lateral unloader bracing in treatment for pathologies effecting the lateral compartment of the knee.

We evaluate patient outcomes following customised lateral unloader bracing (cLUB) in treatment of lateral compartment osteoarthritis (LCOA), lateral tibial plateau fractures (LTPF) and spontaneous osteonecrosis of knee (SONK).

METHODS

Institutional study approval was obtained. All patients undergoing cLUB between January 2013 and January 2021 were included, and prospectively followed-up. Visual Analogue Scales (VAS), Oxford Knee Scores (OKS) and Knee Injury and Osteoarthritis Outcome Scores (KOOS) were assessed at brace fitting and final follow-up. Brace compliance, complications and surgical interventions were also collected. Statistical analysis utilised paired t-test.

Introduction

It is increasingly evident that synovium may play a larger role in the aetiology of osteoarthritis. We compared gene expression in whole tissue synovial biopsies from end-stage knee osteoarthritis and knee trauma patients with that of their paired explant cultures to determine how accurately cultured cells represent holistic synovial function.

Methodology

Synovial tissue biopsies were taken from 16 arthroplasty patients and 8 tibial plateau fracture patients with no osteoarthritis. Pairs of whole tissue fragments were either immediately immersed in RNAlater Stabilisation Solution at 4o C before transfer to -80o C storage until RNA extraction; or weighed, minced and cultured at 500mg tissues/5ml media in a humidified incubator at 37oC, 5% CO2. After sub-culturing total RNA was extracted using RNAeasy Plus Mini Kit with gDNA removal. Following RT-PCR and quality assessment, cDNA was applied to Affymetrix Clariom D microarray gene chips. Bioinformatics analyses were performed.

Introduction

To compare the efficacy of adductor canal blocks (ACB) and periarticular anesthetic injections (PAI) with bupivacaine in total knee arthroplasty.

Methods

90 patients undergoing primary total knee arthroplasty under spinal anesthesia were randomized to 1 of 3 groups: ACB alone (15 mL of 0.5% bupivacaine), PAI alone (50 mL of 0.25% bupivacaine with epinephrine) and ACB + PAI. Primary outcome in this study was the visual analog scale (VAS) pain score in the immediate postoperative period. Secondary outcomes included postoperative opioid use, activity level during physiotheraphy, length of hospital stay and ROM.

Purpose

This study aims to compare the clinical and functional outcomes and donor site morbidity of anterior cruciate ligament reconstruction with hamstring tendon autograft and peroneus longus tendon autograft in patients with complete anterior cruciate ligament rupture.

Methods

Patients who underwent ACL reconstruction from February 2018 to July 2019 were randomly allocated into two groups (hamstring and peroneus longus). Functional scores (IKDC and Lysholm scores) and pain intensity by visual analogue score were recorded preoperatively, 3, 6months, 1, and 2 years postoperatively. Donor site morbidities were assessed with thigh circumference measurements in hamstring group and ankle scoring with the American foot and ankle score in peroneus longus group.

Introduction

There are a wide variety of implant brands and types of knee replacement available to surgeons. With time, the options available within many implant brand portfolios has grown, with alternative tibial or femoral components, tibial insert materials or shapes and patella resurfacings.

Aim

To investigate the effect of the expansion of implant brand portfolios, and to establish the potential numbers of compatible implant construct combinations.

INTRODUCTION

This study investigates whether primary knee arthroplasty (KA) restores health-related quality of life (HRQoL) to levels expected in the general population.

METHODOLOGY

This retrospective case-control study utilises two sources: patients undergoing primary KA from a University Teaching hospital; and individual-level data from the Health Survey for England which was used to represent the General Population.

Propensity score matching was used to balance covariates (sex, age and body mass index (BMI)) and facilitate group comparisons. Two matched cohorts with 3029 patients each were obtained for the adjusted analyses (median age 70.3 interquartile range (IQR) 64–77; Female sex 3233 (53.4%); median BMI 29.7 IQR 26.5-33.7). HRQoL was measured using the three-level version of the EuroQol 5-Dimensions’ (EQ-5D-3L) Index and EQ-VAS scores.

Introduction

It is common practice for all patients to have postoperative bloods tests after total knee arthroplasty (TKA). However there have been significant improvement in perioperative care with arthroplasty surgery. As healthcare systems and providers strive towards a more efficient service we must re-consider whether such an intervention is necessary for all patients.

Methodology

This retrospective study included all patients who underwent a primary unilateral TKA at a single tertiary arthroplasty centre during a 1 year period. Electronic medical records of 776 patients were reviewed for patient demographics, length of stay and American Society of Anaesthesiologists grade. Blood tests were examined to investigate the incidence of post operative anaemia requiring transfusion, electrolyte abnormalities that required treatment and the incidence of acute kidney injury.

Aims

The primary aim of this study was to evaluate the outcomes of fungal knee periprosthetic joint infection following knee arthroplasty. The secondary aim was to evaluate risk factors for acquiring a fungal PJI.

Patients and Methods

This was a retrospective analysis of patients presenting with a confirmed fungal PJI of the knee in two tertiary centres. There were a total of 45 cases. Isolated fungal infections along with mixed bacterial and fungal infections were included. Mean follow up was 40 months (range 3–118).

Background

There is a trend towards minimising length of stay (LOS) after total knee arthroplasty (TKA), as longer LOS is associated with poorer outcomes and higher costs. Patient factors known to influence LOS after TKA include age and ASA grade.

Evidence regarding body mass index (BMI) in particular is conflicting. Some studies find that increased BMI predicts greater LOS, while others find no such relationship. Previous studies have generally not examined socioeconomic status, which may be a confounder. They have generally been conducted outside the UK, and prior to the Covid-19 pandemic.

Methods

We conducted a retrospective cohort study of 1031 primary TKAs performed 01-04-2021 to 31-12-2021, after resumption of elective surgery in our centre. A multivariate regression analysis was performed using a Poisson model over pre-operative variables (BMI, age, gender, ASA grade, index of multiple deprivation, and living arrangement) and peri-operative variables (AM/PM operation, operation side, duration, and day of the week).

Introduction

Osteotomy is a recognised surgical option for the management of unicompartmental knee osteoarthritis. The effectiveness of the surgery is correlated with the accuracy of correction obtained. Overcorrection can potentially lead to excess load through the healthy cartilage resulting in accelerated wear and early failure of surgery. Despite this past studies report this accuracy to be as low as 20% in achieving planned corrections.

Aim

Assess the effectiveness of adopting modern osteotomy techniques in improving surgical accuracy.

Introduction

Anterior cruciate ligament reconstruction (ACLR) can be performed with a number of different autografts including all soft tissue quadriceps autograft. (QT). QT has several advantages including decreased donor site morbidity, reduced anterior knee pain and comparable revision rates compared to other autografts. The primary aim of this review was to assess all complications of QT in adult population.

Methodology

A systematic review of the literature was conducted on in accordance with the PRISMA guidelines using the online databases Medline and EMBASE. Clinical studies or reporting on soft tissue QT were included and appraised using the Methodological Index for Non-Randomized Studies (MINORS) tool.

Design

A pragmatic, multicentre, parallel-group, randomised controlled trial to determine whether the intervention is superior to comparator

Setting

20 NHS Hospitals

Introduction

OtisMed Shape Match ® patient specific implant cutting jigs were designed to place TKA in kinematic alignment (KA) rather than traditional mechanical alignment (MA). This product was withdrawn from the market in 2013.

It has been hypothesised that KA might lead to early implant failure. Initial evidence has not supported this.

We present 10 year outcome data for the largest single centre cohort to date.

Methodology

Between 2010 and 2013, 127 Shape Match® TKAs were implanted in 119 individuals.

Retrospective review of long leg post-operative radiographs assessed femoral mechanical anatomical angle (FMA), tibial mechanical angle (TMA), hip-knee-ankle angle (HKA), posterior tibial slope (PTS) and femoral component flexion.

Oxford Knee Scores (OKS), revision and further surgery rates were reviewed.

Background

Prosthetic joint infection (PJI) is a significant cause of morbidity and mortality following knee replacement surgery. Identifying the causative agent(s) and their antibiotic sensitivities is critical in determining the choice of treatment methods used and the likelihood of successful eradication. This study aimed to investigate:

Methods

We identified consecutive patients passing through our knee infection Multi-Disciplinary Team meeting between December 2014 and March 2020. Data was collated data retrospectively using electronic records. Statistical analysis was performed using Stata (Timberlake, February 2020)

Background

Since 2012 we have routinely used the cementless Oxford medial unicompartmental knee arthroplasty (mUKA), with microplasty instrumentation, in patients with anteromedial osteoarthritis (AMOA) meeting modern indications. We report the 10-year survival of 1000 mUKA with minimum 4-year follow-up.

Methods

National Joint Registry (NJR) surgeon reports were interrogated for each senior author to identify the first 1,000 mUKAs performed for osteoarthritis. A minimum of 4 years follow-up was required. There was no loss to follow-up. The NJR status of each knee was established. For each mUKA revision the indication and mechanism of failure was determined using local patient records. The 10-year implant survival was calculated using life-table analysis.

Aims

Ceramic coatings in total knee arthroplasty have been introduced with the aim of reducing wear and consequently improving implant survivorship. We studied both cobalt-chrome-molybdenum and ceramic-coated components of the same implant design from a single centre to identify if the ceramic coating conferred any benefit at mid-term review.

Patients and Methods

We identified 1641 Columbus TKAs (Aesculap AG, Tüttlingen, Germany) from a prospectively collected arthroplasty database. 983 were traditional CoCrMo and 659 had the AS ceramic coating. Patients were followed up until death or revision of the implant.

Introduction

Cryocompression therapy after knee surgery is widely utilised for post-operative rehabilitation. Skin temperature should be reduced to 10–15°C to maximise the therapeutic benefits while avoiding risks of adverse events. Some cryocompression devices offer control over the temperature of the ice-water circulated through a cuff. The degree to which this corresponds to the achieved skin temperature during a treatment is unknown.

Methods

30 healthy participants volunteered for this prospective randomised crossover trial involving the use of a cryocompression device. Each underwent a 30-minute test in all of five conditions: A, B, C, D and Control. Conditions corresponded to device temperature settings of 6, 8, 10, 12°C and no ice-water circulation, respectively. Skin temperature was measured prior to the cuff being applied, then every 5 minutes during a test.

Introduction

High posterior tibial slope (PTS) has been recognised as a risk factor for anterior cruciate ligament rupture and graft failure. This prospective randomised study looked at intra-operative findings of concomitant intra-articular meniscal and chondral injuries during a planned ACL reconstruction.

Material and Methods

Prospective data was collected as part of a randomised trial for ACL reconstruction techniques. Intra-operative data was collected and these findings were compared with the PTS measured on plain radiograph by a single person twice through a standardised technique and intra-observer analysis was performed.

Introduction

Articular cartilage degradation is a defining feature of osteoarthritis. Synovium is a reactive tissue with synovial villae, neoangiogenesis and intimal hyperplasia common to many joint pathologies. The consequences of cartilage debris in osteoarthritis impacting the synovial intima is not well understood. We analysed the immunohistology of synovium from 16 patients with osteoarthritis and 17 patients undergoing knee surgery for non-arthritic pathologies. This data was integrated with imaging and functional scores to correlate synovitis in osteoarthritis.

Methodology

Formalin-fixed paraffin embedded synovial biopsy sections were cut in serial sequence and processed for routine staining (H&E or CD3, CD68, CD20, Vimentin, vWF and PCNA IHC) using standardised Dako monoclonal mouse anti-human antibodies. Digital images scanned at x20 were evaluated for fragments of cartilage and aggregates of inflammatory cells. Clinical data (gender, BMI, KL grade, WOMAC & SF-12 scores) was aligned with histopathological data.

Introduction

Synovitis impacts osteoarthritis symptomatology and progression. The transcription factors controlling synovial gene expression have not been described. This study analyses gene expression in synovium samples from 16 patients with osteoarthritis with 9 undergoing arthroscopic and 8 knee trauma surgery for non-arthritic pathologies.

Methodology

Intra-operative synovial biopsies were immersed in RNAlater at 4oC before storage at -80oC. Total RNA was extracted using RNAeasy. After purification, RT-PCR and quality assessment, cDNA was applied to Affymetrix Clariom D microarray gene chips. Bioinformatics analyses were performed. Linear models were prepared in limma with gender and BMI factors incorporated sequentially for each pathology comparison, generating 12 models of probes differentially expressed at FDR p<0.05 and Bayes number, B>0. Data analysis of differently expressed genes utilized Ingenuity Pathway Analysis and Cytoscape with Cluego and Cytohubba plug-ins.

Introduction

All-tissue quadriceps tendon (QT) is becoming an increasingly popular alternative to hamstrings tendon (HT) and bone-tendon-bone (BTB) autograft for anterior cruciate ligament (ACL) reconstruction. The relatively short graft length however dictates that one, or both, ends rely on suture fixation. The strength of this construct is therefore extremely important. This study evaluates whether the use of a novel fixation technique can improve the tensile properties of the construct compared to a Krackow suture, and a looped tendon (suture free) gold standard.

Methods

Eighteen porcine flexor tendons were tested, across three groups; suture-tape Krackow, looped tendon, and the novel ‘strain suture’. Biomechanical testing simulated the different stages of ACL graft preparation and loading (60N preload for 10 minutes, 10 cycles from 10N to 75N, and 1000 cycles from 100N to 400N). Elongation and load to failure were recorded, and stiffness calculated for each construct.

Introduction

Mako robotic assisted knee arthroplasty requires a planning CT scan within 8 weeks of surgery according to the supplier's protocol. This is often impractical, therefore we evaluated whether CT scans remain valid for an extended period.

Methodology

Patients undergoing Mako partial (PKA) and total (TKA) knee arthroplasty were identified from our hospital database. The hospital PACS system was used to define the time interval between the initial planning CT scan and surgery, and whether further imaging was required prior to surgery.

Introduction

MRI has been increasingly used as an outcome measure and proxy for healing and integration after ACL reconstruction (ACLR). Despite this, it has not yet been established what a steady state graft MRI appearance is.

Methodology

MRI and clinical outcome measures were prospectively taken at 1 and minimum 2 years after hamstring autograft ACLR. MRI graft signal was measured using novel reconstructions both parallel and perpendicular to the graft, with lower signal indicative of better healing and expressed as the signal intensity ratio (SIR), and tunnel apertures analysed.

Introduction

Elite athletes sustaining a graft re-rupture after ACL reconstruction (ACL-R) undergo revision reconstruction to enable their return to elite sport. The aim of this study was to determine the rate of return to play (RTP) and competition levels at 2 and 5 years post revision ACL-R.

Methodology

A consecutive series of revision ACL-R in elite athletes undertaken by the senior author between 2009 and 2019 was retrospectively reviewed. Outcome measures were RTP rates and competition level.

Introduction

With respect to survivorship following total knee arthroplasty (TKA), joint registries consistently demonstrate higher revision rates for both sexes in those less than 55 years. The current study analyses the survivorship of 500 cementless TKAs performed in this age group in a high-volume primary joint unit where cementless TKA has traditionally been used for the majority of patients.

Methods

This was a retrospective review of 500 consecutive TKAs performed in patients under the age of 55 between March 1994 and April 2017. The primary outcome measure for the study was all-cause revision. Secondary outcome measures included clinical, functional and radiological outcomes.

Aim

End-stage arthropathy is a well-known complication of haemophilia, with recurrent haemarthroses leading to joint destruction, deformity, pain, and stiffness. In the knee, this is often treated with total knee arthroplasty (TKA), which can be more challenging in patients with haemophilia (PwH) and associated with poorer outcomes. We conducted a systematic literature review and meta-analysis to determine implant survivorship, functional outcomes and complication rates.

Method

A systematic review was conducted using MEDLINE, EMBASE, and PubMed for studies reporting TKA outcomes with Kaplan-Meier survivorship in PwH (PROSPERO registered). Meta-analysis was performed for survivorship and outcomes, and the results were compared to outcomes from the National Joint Registry (NJR).

Introduction

This study aimed to assess the effect of PRP on knee articular cartilage content (thickness and/or volume) and establish if there is a correlation between changes in cartilage and clinical outcomes in patients with knee osteoarthritis.

Methodology

A systematic review was performed following the Cochrane methodology. Studies were included if they reported on cartilage content with MRI or Ultrasound before and after the injection. A random-effects model meta-analysis was performed.

Introduction

The incidence of significant acute chondral injuries with patella dislocation is around 10–15%. It is accepted that chondral procedures should only be performed in the presence of joint stability.

Methodology

Patients were identified from surgeon/hospital logs. Patient demographics, lesion size and location, surgical procedure, patient reported outcome measures, post-operative MR imaging and complications were recorded. PROMs and patient satisfaction was obtained.

Methods

A retrospective cohort of 5,857 patients was used to create the prediction models, and a second cohort of 721 patients from a different centre was used to validate the models, all of whom underwent TKA. Patient characteristics, BMI, OKS, and EQ-5D-3L were collected preoperatively and one year postoperatively. Generalized linear regression was used to formulate the prediction models.

Methods

A retrospective, single-surgeon review was carried out of all of the NexGen Legacy Posterior Stabilized (LPS) TKAs performed in this institute. The specific model used for the index procedures was the NexGen Complete Knee System (Legacy Knee-Posterior Stabilized LPS-Flex Articular Surface, LPS-Flex Femoral Component Option, and Stemmed Nonaugmentable Tibial Component Option).

Methods

From January 2008 to December 2010, 266 TKAs were performed in 169 patients with HBV (HBV group). A total of 169 propensity score–matched patients without HBV were chosen for the control group in a one-to-one ratio. Then, the clinical outcomes, mortalities, implant survival rates, and complications of TKA in the two groups were compared. The mean follow-up periods were 11.7 years (10.5 to 13.4) in the HBV group and 11.8 years (11.5 to 12.4) in the control group.

Methods

A total of 501 consecutive AMOA patients (301 UKA) operated on between 2013 to 2016 in two high-volume centres were included. Centre One employed clinical guidelines for the treatment of AMOA allowing either UKA or TKA, but encouraged UKA wherever possible. Centre Two used clinical guidelines that treated all patients with a TKA, regardless of wear pattern. TKA patients were included if they had isolated AMOA on preoperative radiographs. Data were collected from both centres’ local databases. The primary outcome measure was change in Oxford Knee Score (OKS), and the proportion of patients achieving the patient-acceptable symptom state (PASS) at one-year follow-up. The data were 1:1 propensity score matched before regression models were used to investigate potential differences.

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.

Methods

A multicentre randomized trial compared the outcomes of sensor balancing (SB) with manual balancing (MB) in 250 patients (285 TKAs). The primary outcome measure was the mean difference in the four Knee injury and Osteoarthritis Outcome Score subscales (ΔKOOS₄) in the two groups, comparing the preoperative and two-year scores. Secondary outcomes included intraoperative balance data, additional patient-reported outcome measures (PROMs), and functional measures.

Methods

A tibial component with (group S: Attune S+) and without (group A: Attune) additional cement pockets was implanted in 15 fresh-frozen human leg pairs. The relative motion was determined under dynamic loading (extension-flexion 20° to 50°, load-level 1,200 to 2,100 N) with subsequent determination of the maximum pull-out force. In addition, the cement mantle was analyzed radiologically for possible defects, the tibia base cement adhesion, and preoperative bone mineral density (BMD).

Methods

We performed a retrospective review of 75 patients from a single institution who underwent DFA for non-neoplastic indications, including aseptic loosening or mechanical failure of a previous prosthesis (n = 25), periprosthetic joint infection (PJI) (n = 23), and native or periprosthetic distal femur fracture or nonunion (n = 27). Patients with less than 24 months’ follow-up were excluded. We collected patient demographic data, complications, and reoperations. Reoperation for implant failure was used to calculate implant survivorship.

Methods

The CPAK classification was modified by changing the neutral boundaries of aHKA to 0° ± 3° and using aJLO as a new variable. Radiological analysis of 214 healthy knees in 214 Asian individuals was used to assess the distribution and mean value of alignment angles of each phenotype among different classifications based on the coronal plane. Individualized alignment targets were set according to the mean lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) of different knee types.

Methods

A retrospective consecutive study of all patients who underwent a rTKA using this implant from January 2005 to December 2018. Outcome measures included reoperations, revision for any cause, complications, and survivorship. Patients and implant survivorship data were identified through both local hospital electronic databases and linked data from the National Joint Registry/NHS Personal Demographic Service. Kaplan-Meier survival analysis was used at ten years.

Methods

Patients were identified from prospective data on all TKA patients with PJI following the primary procedure. Inclusion criteria were: revision for PJI with bone loss requiring reconstruction, and a minimum five years’ follow-up. Patients were followed up for recurrent infection and assessment of function. Tools used to assess function were Oxford Knee Score (OKS) and American Knee Society Score (AKSS).

Methods

In a cadaveric model, UKA and TKA procedures were performed on eight fresh-frozen knee specimens, using conventional (solid) and titanium lattice tibial implants. Stress at the bone-implant interfaces were measured and compared to the native knee.

Methods

A total of 24 rabbits underwent contracture-forming surgery with knee immobilization followed by remobilization surgery at eight weeks. At remobilization, one cohort underwent capsular release (n = 12), while the other cohort did not (n = 12). Both groups were divided into two subcohorts (n = 6 each) – one receiving IA injections of celecoxib, and the other receiving injections of vehicle solution (injections every day for two weeks after remobilization). Passive extension angle (PEA) was assessed in live rabbits at 10, 16, and 24 weeks, and disarticulated limbs were analyzed for capsular stiffness at 24 weeks.

Methods

This was a retrospective cohort study of 11,550 primary TKAs performed at an orthopaedic hospital between 2013 and 2019. The primary outcome was PJI occurring within 90 days of surgery. Patients were stratified into two groups (cefazolin vs non-cephalosporin) based on their preoperative antibiotic. All patients also received the VIP protocol at wound closure. Bivariate and multiple logistic regression analyses were performed to control for potential confounders and identify the odds ratio of PJI.

Methods

This was a retrospective cohort study of all simultaneous bilateral TKAs performed by a single surgeon in an academic institution between May 2003 and November 2017. Exclusion criteria were the use of partial knee arthroplasty procedures, staged bilateral procedures, and procedures not performed by the senior author on one side and the trainee on another. Primary clinical outcomes of interest included revision and re-revision. Primary functional outcomes included the Oxford Knee Score (OKS) and patient satisfaction scores.

Methods

We retrospectively evaluated knee radiographs of 165 knees, which underwent fixed-bearing PS-TKA with patella resurfacing. The incidence of patella baja and changes in patellar height over a minimum of five years of follow-up were determined using Insall-Salvati ratio (ISR) measurement. We examined whether patella baja (ISR < 0.8) at final follow-up affected clinical outcomes, knee joint range of motion (ROM), and Knee Society Score (KSS). We also assessed inter- and intrarater reliability of ISR measurements and focused on the relationship between patellar height reduction beyond measurement error and clinical outcomes.

Methods

We have retrospectively analyzed the iron studies of a cohort of 2,035 patients undergoing knee joint arthroplasty due to OA.

Methods

This study was a prospective double-blinded placebo-controlled randomized controlled trial to compare the efficacy of combined ACB+ IAC-ropivacaine infusion (study group, n = 68) versus single-shot ACB+ intra-articular normal saline placebo (control group, n = 66) after primary TKA. The primary outcome was assessment of pain, using the visual analogue scale (VAS) recorded at 6, 12, 24, and 48 hours after surgery. Secondary outcomes included active knee ROM 48 hours after surgery and additional requirement of analgesia for breakthrough pain.

Methods

Soccer athletes enrolled in a prospective multicentre cohort were contacted to collect ancillary data on their participation in soccer and their return to play following rACLR. Information regarding if and when they returned to play and their current playing status was recorded. If they were not currently playing soccer, they were asked the primary reason they stopped playing. Information on any subsequent knee surgery following their index rACLR was also collected. Player demographic data and graft choice were collected from their baseline enrolment data at rACLR.

Methods

A prospective cohort study of 165 patients undergoing functionally-aligned TKA was performed (176 TKAs). With trial components in situ, medial and lateral extension and flexion gaps were measured using robotic navigation while applying valgus and varus forces. The ICLD between medial and lateral compartments was measured in extension and flexion with the load sensor. The null hypothesis was that stressed gap symmetry would not correlate directly with sensor-defined soft tissue balance.

Methods

The aim of the study is to compare navigated kinematically aligned TKAs (KA TKAs) with navigated mechanically aligned TKA (MA TKA) in terms of function and ROM. We aim to recruit a total of 96 patients in the trial. The patients will be recruited from clinics of various consultants working in the trust after screening them for eligibility criteria and obtaining their informed consent to participate in this study. Randomization will be done prior to surgery by a software. The primary outcome measure will be the Knee injury and Osteoarthritis Outcome Score The secondary outcome measures include Oxford Knee Score, ROM, EuroQol five-dimension questionnaire, EuroQol visual analogue scale, 12-Item Short-Form Health Survey (SF-12), and Forgotten Joint Score. The scores will be calculated preoperatively and then at six weeks, six months, and one year after surgery. The scores will undergo a statistical analysis.

Methods

Through our institution’s total joint registry, we identified 113 primary TKAs (103 patients) performed between 2007 and 2017 in which a VVC insert was coupled with a standard cemented PS femur without stems. Mean age was 68 years (SD 10), mean BMI was 32 kg/m² (SD 7), and 59 patients (50%) were male. Mean follow-up was four years (2 to 10).

Methods

A per protocol analysis of 76 patients, 43 of whom underwent TKA and 34 of whom underwent bi-UKA, was performed from a prospective, single-centre, randomized controlled trial. Diaries kept by the patients recorded pain, function, and the use of analgesics daily throughout the first week and weekly between the second and sixth weeks. Patient-reported outcome measures (PROMs) were compared preoperatively, and at three months and one year postoperatively. Data were also compared longitudinally and a subgroup analysis was conducted, stratified by preoperative PROM status.

Methods

A total of 31 patients were recruited to this single-group radiostereometric analysis (RSA) study and received a medial pivot GMK Sphere TKA. The distributions of male patients versus female patients and right versus left knees were 21:10 and 17:14, respectively. Mean BMI was 29 kg/m² (95% confidence interval (CI) 27 to 30) and mean age at surgery was 63 years (95% CI 61 to 66). Maximum total point motions (MTPMs), medial, proximal, and anterior translations and transversal, internal, and varus rotations were calculated at three, 12, and 24 months. Patient-reported outcome measure data were also retrieved.

Methods

We conducted a prospective, double-centre study of 40 patients with 40 knee joints. Patients underwent joint aspiration at two different time points with a maximum period of 120 days in between these interventions and without any events such as other joint aspirations or surgeries. The main indications for TKA revision surgery were aseptic implant loosening (n = 24) and joint instability (n = 11).

Methods

In order to determine the best tibial tray cementation technique, we applied cement to 40 cryopreserved donor tibiae by four different techniques: 1) double-layer cementation of the tibial component and tibial bone with bone restrictor; 2) metallic cementation of the tibial component without bone restrictor; 3) bone cementation of the tibia with bone restrictor; and 4) superficial bone cementation of the tibia and metallic keel cementation of the tibial component without bone restrictor. We performed CT exams of all 40 subjects, and measured cement layer thickness at both levels of the resected surface of the epiphysis and the endomedular metaphyseal level.

Methods

A consecutive cohort of 149 patients who had undergone semitendinosus autograft ACL reconstruction, using femoral and tibial adjustable loop fixations, were evaluated retrospectively postoperatively at two years. All underwent MRI analysis of the ACL graft, performed using signal-to-noise quotient (SNQ) and the Howell score. Functional outcome scores (Lysholm, Tegner, International Knee Documentation Committee (IKDC) subjective, and IKDC objective) were obtained and all patients underwent instrumented side-to-side anterior laxity differential laxity testing.

Methods

Classification categories were proposed by a surgical consensus group, then ranked by patients, according to perceived invasiveness and implications for recovery. In round one, 26 revision cases were classified by the consensus group. Results were tested for inter-rater reliability. In round two, four additional cases were added for clarity. Round three repeated the survey one month later, subject to inter- and intrarater reliability testing. In round four, five additional expert partial knee arthroplasty surgeons were asked to classify the 30 cases according to the proposed revision partial knee classification (RPKC) system.

Methods

The trial design was a prospective, randomized, parallel, single-centre study comparing surgical alignment in patients undergoing UKA for the treatment of medial compartment osteoarthritis (ISRCTN77119437). Participants underwent surgery using either robotic arm-assisted surgery or conventional manual instrumentation. The primary outcome measure (surgical accuracy) has previously been reported, and, along with secondary outcomes, were collected at one-, two-, and five-year timepoints. Analysis of five-year results and longitudinal analysis for all timepoints was performed to compare the two groups.

Methods

Genome-wide association (GWA) analyses were performed using data from the Kaiser Permanente Research Board (KPRB) and the UK Biobank. ACL and PCL injury cases were identified based on electronic health records from KPRB and the UK Biobank. GWA analyses from both cohorts were tested for ACL and PCL injury using a logistic regression model adjusting for sex, height, weight, age at enrolment, and race/ethnicity using allele counts for single nucleotide polymorphisms (SNPs). The data from the two GWA studies were combined in a meta-analysis. Candidate genes previously reported to show an association with ACL injury in athletes were also tested for association from the meta-analysis data from the KPRB and the UK Biobank GWA studies.

Methods

For patients undergoing short knee arthroscopic procedures, a sterile calibrated pH probe was inserted into the anterior fascial compartment of the leg after skin preparation, but before tourniquet inflation. The limb was elevated for three minutes prior to tourniquet inflation to 250 mmHg or 300 mmHg. Intramuscular pH was recorded at one-second intervals throughout the procedure and for 20 minutes following tourniquet deflation. Probe-related adverse events were recorded.

Methods

Using an US system, which is fitted with an electromagnetic (EM) tracker that is integrated into the US probe, allows 3D tracking of the probe, femur, and tibia. The raw US radiofrequency (RF) signals are acquired and, using real-time signal processing, bone boundaries are extracted. Bone boundaries and the tracking information are fused in a 3D point cloud for the femur and tibia. Using a statistical shaping model, the patient-specific surface is reconstructed by optimizing bone geometry to match the point clouds. An accuracy analysis was conducted for 17 cadavers by comparing the 3D US models with those created using CT. US scans from 15 users were compared in order to examine the effect of operator variability on the output.

Methods

A comparative cross-sectional, radiological study was undertaken of 500 normal knees and 500 arthritic knees undergoing TKA. By definition, the aHKA algorithm subtracts the lateral distal femoral angle (LDFA) from the medial proximal tibial angle (MPTA). The mechanical HKA (mHKA) of the normal group was compared to the mHKA of the arthritic group to examine the difference, specifically related to deformity in the latter. The mHKA and aHKA were then compared in the normal group to assess for differences related to joint line convergence. Lastly, the aHKA of both the normal and arthritic groups were compared to test the hypothesis that the aHKA can estimate the constitutional alignment of the limb by sharing a similar centrality and distribution with the normal population.

Methods

A total of 84 patients, with a mean age of 68 years (36 to 92), underwent single-stage revision TKA for confirmed PJI at a single institution between 2006 and 2016. In all, 37 patients (44%) were treated for an infected primary TKA, while the majority presented with infected revisions: 31 had undergone one previous revision (36.9%) and 16 had multiple prior revisions (19.1%). Contraindications to single-stage exchange included systemic sepsis, extensive bone or soft-tissue loss, extensor mechanism failure, or if primary wound closure was unlikely to be achievable. Patients were not excluded for culture-negative PJI or the presence of a sinus.

Methods

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled trials, and trial registries up to 26 March 2020. We included randomized controlled trials (RCTs), comparing TKA with a tourniquet versus without a tourniquet. Outcomes included: pain, function, serious adverse events (SAEs), blood loss, implant stability, duration of surgery, and length of hospital stay.

Methods

A total of 34 Japanese white rabbits (divided into defect and atelocollagen groups) were used to produce the massive meniscus defect model through a medial patellar approach. Cell migration and proliferation were evaluated using immunohistochemistry. Furthermore, histological evaluation of the sections was performed, and a modified Pauli’s scoring system was used for the quantitative evaluation of the regenerated meniscus.

Methods

Postoperative radiological outcomes from 86 consecutive robotic-assisted UKAs (RAUKA group) from a single academic centre were retrospectively reviewed and compared to 253 manual UKAs (MUKA group) drawn from a prior study at our institution. Femoral coronal and sagittal angles (FCA, FSA), tibial coronal and sagittal angles (TCA, TSA), and implant overhang were radiologically measured to identify outliers.

Methods

A radiological analysis of 500 healthy and 500 osteoarthritic (OA) knees was used to assess the applicability of the CPAK classification. CPAK comprises nine phenotypes based on the arithmetic HKA (aHKA) that estimates constitutional limb alignment and joint line obliquity (JLO). Intraoperative balance was compared within each phenotype in a cohort of 138 computer-assisted TKAs randomized to KA or MA. Primary outcomes included descriptive analyses of healthy and OA groups per CPAK type, and comparison of balance at 10° of flexion within each type. Secondary outcomes assessed balance at 45° and 90° and bone recuts required to achieve final knee balance within each CPAK type.

Methods

We present a case-series of consecutive patients treated at our institution due to a severe fungal osteomyelitis after an arthroscopic ACL-R from November 2005 to March 2015. Patients were referred to our institution from different areas of our country. We evaluated the amount of bone resection required, type of final reconstructive procedure performed, and Musculoskeletal Tumor Society (MSTS) functional score.

Methods

In total, 11 different PTS (0° to 10°) values were simulated to evaluate the effect of PTS on anterior post-cam contact conditions and knee kinematics in BCS TKA during weight-bearing stair climbing (from 86° to 6° of knee flexion). Knee kinematics were expressed as the lowest points of the medial and lateral femoral condyles on the surface of the tibial insert, and the anteroposterior translation of the femoral component relative to the tibial insert.

Methods

An analysis of 38 patients who underwent TKA and 32 who underwent bi-UKA was performed as a secondary study from a prospective, single-centre, randomized controlled trial. CT imaging was used to measure coronal, sagittal, and axial alignment of the knee preoperatively and at three months postoperatively to determine changes in anatomy that had occurred as a result of the surgery. The hip-knee-ankle angle (HKAA) was also measured to identify any differences between the two groups.

Methods

Well-functioning primary TKAs (n = 11), failed non-fibrotic TKAs (n = 5), and patients with a clinical diagnosis of fibrosis¹ (n = 8) underwent an MRI scan with advanced metal suppression (Slice Encoding for Metal Artefact Correction, SEMAC) with gadolinium contrast. Fibrotic tissue (low intensity on T1 and T2, low-moderate post-contrast enhancement) was quantified (presence and tissue thickness) in six compartments: supra/infrapatella, medial/lateral gutters, and posterior medial/lateral.

Methods

We examined the records of 29,270 patients who underwent a primary total joint arthroplasty (TJA), defined as a unilateral total knee arthroplasty (TKA) (18,987) or total hip arthroplasty (THA) (10,283), between 2/2016 and 12/2018 at our institution and identified 338 (242 TKA, 96 THA) patients who developed an in-hospital PE treated with therapeutic anticoagulation. The patients were treated with therapeutic doses of Xa inhibitors, enoxaparin or warfarin. The type and frequency of complications were determined and classified as major or minor. Major complication included: bleeding requiring surgery, GI bleed requiring treatment, >2 unit transfusion and mortality. Minor complications included wound drainage, bleeding not requiring surgery, and thrombocytopenia.

Methods

We retrospectively identified 27,066 primary TKAs performed between 2000–2019. Within 12 weeks, 171 knees (170 patients) had a synovial fluid aspiration. Patients were divided into two groups: evaluation <6 weeks or 6–12 weeks. The 2011 MSIS criteria for PJI diagnosed infection in 22 knees. Mann-Whitney U tests compared medians; ROC analyses determined optimal thresholds. Mean follow-up was 5 years.

Methods

This prospective randomised controlled trial included 30 patients with symptomatic knee osteoarthritis undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localised knee temperature were collected preoperatively and postoperatively at 6 hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned limb alignment and implant positioning in both treatment groups.

Methods

The data of 131 consecutive patients enrolled in a prospective trial was reviewed. All TKAs were performed using a dynamic ligament tensioning robotic system with a tibial first resection technique and a cruciate sacrificing ultracongruent knee implant. Each TKA was graded based on the final recorded mediolateral ligament balance at 10° and 90°: A) <1mm with an implanted insert thickness equal to planned (n=74); B) <1mm (n=25); C) <2mm (n=26); D) >2mm (n=6) (Table-1). The 1-year KPS for each knee grade were compared and the likelihood of achieving an KPS > 90 was calculated. Finally, the factors associated with lower KPS despite achieving a high grade TKA (A/B) was performed. The Mann-Whitney U test and Chi-squared analysis was performed.

Methods

A multicenter prospective randomized control trial was conducted evaluating the use of the mymobility smartphone-based care platform for primary total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA). Patients in the control group (224 patients) received the respective institution's standard of care typically with formal physical therapy. Those randomized to mymobility treatment group (192 patients) were provided an Apple Watch and mymobility smartphone application. The treatment group was not initially prescribed physical therapy, but could if their surgeon determined it necessary. Early outcomes assessed included 90-day knee range of motion, KOOS Jr scores, 30-day single leg stance (SLS) time, Time up and Go (TUG) time and need for manipulation under anesthesia (MUA). There was no significant difference in age, BMI or gender between groups.

Methods

We retrospectively reviewed 1,724 consecutive risk stratified patients undergoing primary unilateral TKA. The mean age was 64.8 years and average body mass index (BMI) was 34.2 kg/m2. All patients underwent preoperative optimization using the RST. We first compared our primary variables of interest between obese (BMI>30, n=1,189) and non-obese patients (n=535). Patients were then divided into 3 groups (I-non-obese, II-obese (30–39.9 kg/m2) and III-morbidly obese ((>40 kg/m2)) and logistic regression was used to evaluate outcomes among the groups adjusted for age, sex, smoking history and diabetes.

Methods

This study investigated the penetration of topical diclofenac into knee synovial tissue and fluid and evaluated relative exposure in the knee versus plasma. In this phase 1, double-blind, placebo-controlled steady-state multicenter pharmacokinetic study, patients scheduled for arthroplasty to treat knee OA were randomly assigned 2:1 to 4 g diclofenac/placebo gel, applied to the affected knee every 12 hours for 7 days pre-surgery. Diclofenac concentrations were measured in synovial tissue, fluid, and plasma ≥12 hours after last application. Adverse events (AEs) were evaluated. Diclofenac concentrations were assayed by validated high-performance liquid chromatography and tandem mass spectrometry.

Methods

The CBH had a main operating floor and a separate floor of four OR suites which were repurposed with the goal of utilizing these rooms for TJA four days per week with an average of 3.5 cases per room per day. We preferentially performed primary, uncomplicated TJA, UKA, and minimally invasive TJA at the CBH. Revision surgeries, patients with extensive medical comorbidities, and complex primary surgeries would be performed at the AMC. Our goals were to decrease costs, readmissions, length of stay, and increase margins at the CBH while increasing efficiency, revenue and volume. Protocols were developed to facilitate SDD UKA and THA at both hospitals as well as rapid recovery protocols for TKA at both hospitals with the understanding that the CBH would perform more of these cases but the efficiency could also be implemented at the AMC when possible. We also needed a strategy to deal with TKA and eventually THA being removed from the Inpatient Only (IPO) list. CMS has utilized the “Two-Midnight Rule” to define outpatient status for both THA and TKA. This has distinct financial implications for the facility's reimbursement with outpatient being $10,123 on average versus $12,380 for inpatient status. A protocol-based system was put in place to make both hospitals compliant with the removal of TKA from the IPO List in order to avoid Quality Improvement Organization (QIO) and Recovery Audit Contractor (RAC) after implementation.

Results

Comparing FY 2018 to FY 2019, volume increased 26.4% at the CBH. Outpatient case volume rose substantially from 14 cases to 243. Volumes were slightly decreased at the AMC (−4.57%) resulting in a substantial increase in margin contribution for the parent enterprise. Quality metrics at the CBH (surgical site infections (SSI), length of stay (LOS), readmissions, and mortality) were improved. LOS improved from 52% to 71% discharge before 48 hours. The LOS decreased 12% for THA and 8.1% for TKA. CBH readmission rates decreased from 1.38% to 0.9% with no deaths. Surgeon satisfaction is greatly improved as their volume, efficiency, quality metrics, and finances were enhanced.

Financial performance was improved in aggregate and per case for the CBH. Although the CBH per-case revenue was 80.3% and 74.4% of the AMC for THA and TKA: the net margins were 3.6% and 18.8% higher for THA and TKA, respectively. The increased efficiency, lower hospital cost and higher volume at the CBH allowed for an increase in revenue despite lower reimbursement per case.

Methods

We performed a single center retrospective review from 2015 to 2018 of all primary TKA. Patient demographics, medial proximal tibial angle (mPTA), lateral distal femoral angle (lDFA), flexion contracture, cost of care, and early postoperative outcomes were collected. ‘Complex’ patients were defined as those requiring stems or augments, and multivariable logistic regression analysis and propensity score matching were performed to evaluate perioperative outcomes.

Methods

This was a retrospective cohort study comparing patients who underwent revision TKA utilizing cemented or uncemented tibial stems in a 15-year period at a single institution with at least two-year follow-up. Exclusion criteria included age under 18, isolated revisions of the femoral component or polyethylene exchanges, lack of preoperative or postoperative imaging, insufficient operative or implant records available for electronic chart review, revision procedures performed at outside facilities, patients who were deceased at the time of survey administration, refusal to participate in the study, and failure to return the mailed survey or respond to a telephone follow-up questionnaire. Radiographic analysis included calculation of the percentage of the tibial canal filled with the implant, as well as measurement of the diameter of the tibial stem. Radiographs were also reviewed for evidence of cavitary defects, pedestal formation, radiolucent lines, and periprosthetic fractures. Mailed surveys addressing overall pain, tibial pain, and satisfaction were analyzed using Fisher's exact test and the independent sample t-test. Logistic regression was used to adjust for age, gender, and preoperative bone loss.

Methods

Six pelvis-to-toe specimens (72±6 years old, four females) were implanted by an expert surgeon with a PS TKA using measured resection. Pliable sensors were wrapped around medial and lateral aspects of the foot and ankle to measure the applied forces. The forces were scaled by limb length to obtain the moments generated at the knee. Six surgeons with different experience levels independently assessed balance by applying moments in extension and 90° of flexion and choosing the insert they believed fit each knee. Peak moments and the accompanying extension and flexion gap openings as perceived by surgeons were recorded. The two measures were then related to insert choice using a generalized estimating equation.

Methods

Prospective consecutive series of 100 patients undergoing total knee arthroplasty using computer navigation. First cohort of 50 patients had extramedullary cutting jig secured distally with ankle clamp and proximally with one pin and a second cohort of 50 patients with the jig secured distally with ankle clamp and proximally with two pins. The change in coronal alignment was recorded with each degree of increasing posterior slope from 0–7° using computer navigation. Mean coronal alignment and change in coronal alignment was compared between the two cohorts.