Aims

Accurate identification of the ankle joint centre is critical for estimating tibial coronal alignment in total knee arthroplasty (TKA). The purpose of the current study was to leverage artificial intelligence (AI) to determine the accuracy and effect of using different radiological anatomical landmarks to quantify mechanical alignment in relation to a traditionally defined radiological ankle centre.

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We compared the risks of re-revision and mortality between two-stage revision surgery and single-stage revision surgery among patients with infected primary knee arthroplasty.

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Unicompartmental and total knee arthroplasty (UKA and TKA) are successful treatments for osteoarthritis, but the solid metal implants disrupt the natural distribution of stress and strain which can lead to bone loss over time. This generates problems if the implant needs to be revised. This study investigates whether titanium lattice UKA and TKA implants can maintain natural load transfer in the proximal tibia.

Between 1989 and 1992 we had 102 knees suitable for unicompartmental knee replacement (UKR). They were randomised to receive either a St Georg Sled UKR or a Kinematic modular total knee replacement (TKR). The early results demonstrated that the UKR group had less complications and more rapid rehabilitation than the TKR group. At five years there were an equal number of failures in the two groups but the UKR group had more excellent results and a greater range of movement. The cases were reviewed by a research nurse at 8, 10 and 12 years after operation. We report the outcome at 15 years follow-up. A total of 43 patients (45 knees) died with their prosthetic knees intact. Throughout the review period the Bristol knee scores of the UKR group have been better and at 15 years 15 (71.4%) of the surviving UKRs and 10 (52.6%) of the surviving TKRs had achieved an excellent score. The 15 years survivorship rate based on revision or failure for any reason was 24 (89.8%) for UKR and 19 (78.7%) for TKR. During the 15 years of the review four UKRs and six TKRs failed. The better early results with UKR are maintained at 15 years with no greater failure rate. The median Bristol knee score of the UKR group was 91.1 at five years and 92 at 15 years, suggesting little functional deterioration in either the prosthesis or the remainder of the joint. These results justify the increased use of UKR

We analysed data from the Oxford hip and knee questionnaires collected by the New Zealand Joint Registry at six months and five years after joint replacement, to determine if there was any relationship between the scores and the risk of early revision. Logistic regression of the six-month scores indicated that for every one-unit decrease in the Oxford score, the risk of revision within two years increased by 9.7% for total hip replacement (THR), 9.9% for total knee replacement (TKR) and 12.0% for unicompartmental knee replacement (UKR). Our findings showed that 70% of the revisions within two years for TKR and 67% for THR and UKR would have been captured by monitoring the lowest 22%, 28% and 28%, respectively, of the Oxford scores. When analysed using the Kalairajah classification a score of < 27 (poor) was associated with a risk of revision within two years of 7.6% for THR, 7.0% for TKR and 24.3% for UKR, compared with risks of 0.7%, 0.7% and 1.8%, respectively, for scores > 34 (good or excellent). Our study confirms that the Oxford hip and knee scores at six months are useful predictors of early revision after THR and TKR and we recommend their use for the monitoring of the outcome and potential failure in these patients

The purpose of this study was to measure the radiological parameters of femoral component alignment of the Oxford Phase 3 unicompartmental knee replacement (UKR), and evaluate their effect on clinical outcome. Multiple regression analysis was used to examine the relative contributions of the radiological assessment of femoral component alignment in 189 consecutive UKRs performed by a single surgeon. The American Knee Society scores were compared between groups, defined as being within or outside recommended tolerances of the position of the femoral component. For the flexion/extension position 21 UKRs (11.1%) lay outside the recommended limits, and for posterior overhang of the femoral component nine (4.8%) lay outside the range. The pre-operative hip/knee/ankle (HKA) angle, narrowest canal distance from the distal femoral entry point of the alignment jig and coronal entry-point position had significant effects on the flexion/extension position. Pre-operative HKA angle had a significant influence on posterior overhang of the femoral component. However, there was no significant difference in American Knee Society scores relative to the position of the femoral component

Aims

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common orthopaedic procedures requiring postoperative radiographs to confirm implant positioning and identify complications. Artificial intelligence (AI)-based image analysis has the potential to automate this postoperative surveillance. The aim of this study was to prepare a scoping review to investigate how AI is being used in the analysis of radiographs following THA and TKA, and how accurate these tools are.

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To identify the responsiveness, minimal clinically important difference (MCID), minimal clinical important change (MIC), and patient-acceptable symptom state (PASS) thresholds in the 36-item Short Form Health Survey questionnaire (SF-36) (v2) for each of the eight dimensions and the total score following total knee arthroplasty (TKA).

Medium-term survivorship of the Oxford phase 3 unicompartmental knee replacement (UKR) has not yet been established in an Asian population. We prospectively evaluated the outcome of 400 phase 3 Oxford UKRs in 320 Korean patients with a mean age at the time of operation of 69 years (48 to 82). The mean follow-up was 5.2 years (1 to 10). Clinical and radiological assessment was carried out pre- and post-operatively. At five years, the mean Knee Society knee and functional scores had increased significantly from 56.2 (30 to 91) pre-operatively to 87.2 (59 to 98) (p = 0.034) and from 59.2 (30 to 93) to 88.3 (50 to 100) (p = 0.021), respectively. The Oxford knee score increased from a mean of 25.8 (12 to 39) pre-operatively to 39.8 (25 to 58) at five years (p = 0.038). The ten-year survival rate was 94% (95% confidence interval 90.1 to 98.0). A total of 14 UKRs (3.5%) required revision. The most common reason for revision was dislocation of the bearing in 12 (3%). Conversion to a total knee replacement was required in two patients who developed osteoarthritis of the lateral compartment. This is the largest published series of UKR in Korean patients. It shows that the mid-term results after a minimally invasive Oxford phase 3 UKR can yield satisfactory clinical and functional results in this group of patients

The lateral compartment is predominantly affected in approximately 10% of patients with osteoarthritis of the knee. The anatomy, kinematics and loading during movement differ considerably between medial and lateral compartments of the knee. This in the main explains the relative protection of the lateral compartment compared with the medial compartment in the development of osteoarthritis. The aetiology of lateral compartment osteoarthritis can be idiopathic, usually affecting the femur, or secondary to trauma commonly affecting the tibia. Surgical management of lateral compartment osteoarthritis can include osteotomy, unicompartmental knee replacement and total knee replacement. This review discusses the biomechanics, pathogenesis and development of lateral compartment osteoarthritis and its management. Cite this article: Bone Joint J 2013;95-B:436–44

Our aim was to determine the pre-operative sporting profiles of patients undergoing primary joint replacement and to establish if they were able to return to sport after surgery. A postal survey was completed by 2085 patients between one and three years after operation. They had undergone one of five operations, namely total hip replacement, hip resurfacing, total knee replacement, unicompartmental knee replacement or patellar resurfacing. In the three years before operation 726 (34.8%) patients were participating in sport, the most common being swimming, walking and golf. A total of 446 (61.4%) had returned to their sporting activities by one to three years after operation and 192 (26.4%) were unable to do so because of their joint replacement, with the most common reason being pain. The largest decline was in high-impact sports including badminton, tennis and dancing. After controlling for the influence of age and gender, there was no significant difference in the rate of return to sport according to the type of operation

Aims

Uncemented mobile bearing designs in medial unicompartmental knee arthroplasty (UKA) have seen an increase over the last decade. However, there are a lack of large-scale studies comparing survivorship of these specific designs to commonly used cemented mobile and fixed bearing designs. The aim of this study was to evaluate the survivorship of these designs.

Aims

There is conflicting evidence on the safety of intra-articular injections of hyaluronic acid (HA) or corticosteroids (CSs) before total knee arthroplasty (TKA). We performed a meta-analysis of the relationship between intra-articular injections and subsequent infection rates after TKA.

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The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery.

Artificial intelligence and machine-learning analytics have gained extensive popularity in recent years due to their clinically relevant applications. A wide range of proof-of-concept studies have demonstrated the ability of these analyses to personalize risk prediction, detect implant specifics from imaging, and monitor and assess patient movement and recovery. Though these applications are exciting and could potentially influence practice, it is imperative to understand when these analyses are indicated and where the data are derived from, prior to investing resources and confidence into the results and conclusions. In this article, we review the current benefits and potential limitations of machine-learning for the orthopaedic surgeon with a specific emphasis on data quality.

Aims

The cemented Oxford unicompartmental knee arthroplasty (OUKA) features two variants: single and twin peg OUKA. The purpose of this study was to assess the stability of both variants in a worst-case scenario of bone defects and suboptimal cementation.

We present a comparison of patient-reported outcomes (PROMs) in relation to patient age, in patients who had received a total (TKR) or unicompartmental knee replacement (UKR). The outcome was evaluated using the Oxford knee score (OKS), EuroQol (EQ-5D) and satisfaction scores. Patients aged 65 to 84 years demonstrated better pre-operative function scores than those aged < 65 years (OKS, p = 0.03; EQ-5D, p = 0.048) and those aged ≥ 85 years (OKS, p = 0.03). Post-operative scores were comparable across age groups, but a linear trend for greater post-operative improvement in OKS and EQ-5D was seen with decreasing age (p < 0.033). The overall mean satisfaction score at six months was 84.9, but those aged <  55 years exhibited a lower mean level of satisfaction (78.3) compared with all other age groups (all p < 0.031). The cumulative overall two-year revision rate was 1.3%. This study demonstrates that good early outcomes, as measured by the OKS and EQ-5D, can be anticipated following knee replacement regardless of the patient’s age, although younger patients gain greater improvement. However, the lower satisfaction in those aged < 55 years is a concern, and suggests that outcome is not fully encapsulated by the OKS and EQ-5D evaluation, and raises the question whether the OKS alone is an appropriate measure of pain and function in younger, more active individuals. Cite this article: Bone Joint J 2013;95-B:38–44

Aims

Elective orthopaedic surgery was cancelled early in the COVID-19 pandemic and is currently running at significantly reduced capacity in most institutions. This has resulted in a significant backlog to treatment, with some hospitals projecting that waiting times for arthroplasty is three times the pre-COVID-19 duration. There is concern that the patient group requiring arthroplasty are often older and have more medical comorbidities—the same group of patients advised they are at higher risk of mortality from catching COVID-19. The aim of this study is to investigate the morbidity and mortality in elective patients operated on during the COVID-19 pandemic and compare this to a pre-pandemic cohort. Primary outcome was 30-day mortality. Secondary outcomes were perioperative complications, including nosocomial COVID-19 infection. These operations were performed in a district general hospital, with COVID-19 acute admissions in the same building.

Aims

There is little published on the outcomes after restarting elective orthopaedic procedures following cessation of surgery due to the COVID-19 pandemic. During the pandemic, the reported perioperative mortality in patients who acquired SARS-CoV-2 infection while undergoing elective orthopaedic surgery was 18% to 20%. The aim of this study is to report the surgical outcomes, complications, and risk of developing COVID-19 in 2,316 consecutive patients who underwent elective orthopaedic surgery in the latter part of 2020 and comparing it to the same, pre-pandemic, period in 2019.