Introduction. Achieving a balanced joint with neutral alignment is not always possible in total knee arthroplasty (TKA). Intra-operative compromises such as accepting some joint imbalance, non-neutral alignment or soft-tissue release may result in worse patient outcomes, however, it is unclear which compromise will most impact outcome. In this study we investigate the impact of post-operative soft tissue balance and component alignment on postoperative pain. Methods. 135 patients were prospectively enrolled in robot assisted TKA with a digital joint tensioning tool (OMNIBotics with BalanceBot, Corin USA) (57% female; 67.0 ± 8.1 y/o; BMI: 31.9 ± 4.8 kg/m. 2. ). All surgeries were performed with a PCL sacrificing tibia or femur first techniques technique, using CR femoral components and a deep dish tibial insert (APEX, Corin USA). Gap measurements were acquired under load (average 80 N) throughout the range of motion during trialing with the tensioning tool inserted in place of the tibial trial. Component alignment parameters and post-operative joint gaps throughout flexion were recorded. Patients completed 1-year KOOS pain questionnaires. Spearman correlations and Mann-Whitney-U tests were used to investigate continuous and categorical data respectively. All analysis performed in R 3.5.3. Results. Significant correlations were found between KOOS Pain and joint balance (p < 0.05). Joint gap thresholds of an equally balanced or tighter medial compartment in extension, ±1 mm medial laxity compared to the final insert thickness in midflexion, and medio-lateral imbalance < 1.5 mm in flexion generated subgroups with significantly improved pain outcomes (median Δ = 8.3, 5.6 and 2.8 points, respectively). When all joint balance thresholds were satisfied, further improved outcomes resulted (median Δ = 11.2, p = 0.0018) (Figure 1 Left). No significant correlations were identified between femoral coronal (0.8 ± 2.1° valgus) and axial (2.1 ± 2.7° external) or tibiofemoral extension (1.1 ± 2.4° varus) and flexion (2.4 ± 2.8° varus) coronal alignments and KOOS Pain. Neutral and non-neutral femoral (±3° coronal and 0° – 5° external) and tibiofemoral (±3° coronal and −2° − 5° external) subgroups also reported no difference in KOOS pain outcome (Figure 1 Right). Discussion and Conclusion. The gap profiles identified here help build the understanding of joint balance and its relationship with outcome when using a PCL sacrificing deep dish tibial insert. Using a digitally-controlled distraction device, joint gap windows of clinical relevance were identified with statistically improved patient outcomes. By combining joint gap targets, subpopulations were identified with clinically significant improved pain outcomes. Furthermore, small changes in component alignment did not impact 1 yr pain outcomes, indicating soft tissue balance has a greater impact on outcome that alignment in the enrolled population. For any figures or tables, please contact the authors directly

Aims

Total hip arthroplasty (THA) is a common procedure to address pain and enhance function in hip disorders such as osteoarthritis. Despite its success, postoperative patient recovery exhibits considerable heterogeneity. This study aimed to investigate whether patients follow distinct pain trajectories following THA and identify the patient characteristics linked to suboptimal trajectories.

Background and Purpose: How outcomes of clinical trials are reported alters the way treatment effectiveness is perceived. Clinicians interpret outcomes of trials more favourably when results are presented in relative rather than in absolute terms. However, the face validity of different methods is unclear. We aimed to explore which methods clinicians find clearest, most interpretable, and useful.

Methods and Results: We purposively sampled clinicians who see patients with low back pain (LBP) and presented them with summary reports of a hypothetical trial, reporting the results using a variety of different methods. We explored participants’ preferences for these different methods and how they would like to see future trials reported. We interviewed 14 clinicians (GPs, manual therapists, psychologists, a rheumatologist, and surgeons). Participants felt that clinical trial reports were not written with them in mind. They were familiar with mean differences, proportion improved, and number needed to treat (NNT); and unfamiliar with standardised mean difference (SMD), odds ratios and relative risk. They found the proportion improved, relative risk and NNT more intuitively understandable, and were concerned that between-group mean difference, relative risk and odds ratios may mislead. Participants thought each method uniquely contributed to their overall understanding, and that using a variety of methods to report future trials may prevent erroneous portrayal of treatment effect.

Conclusion: Clinicians who see patients with low back pain currently find it difficult to interpret LBP trials. Using a suite of methods to report outcomes may aid clinicians’ interpretation and the transition of research into practice.

Conflict of Interest: None

Sources of Funding: Barts and the London Charity

There is a desire to reduce the economic burden of low back pain. This in is part because of the 226% increase in invalidity benefits paid out for spinal disorders in the ten years to 1994/5. This paper examines the effect of the change from Invalidity Benefit to Incapacity Benefit in 1995, and considers the utility of these figures as a means of assessing changing patterns of back pain disability.

Data were obtained from the DSS on how benefit data were collected and numbers of days of Invalidity/Incapacity Benefits that were paid from 1983/4 to 1998/9. The data suggest that since 1995 that the rate of spinal disability has fallen and has now been stable at 90 million days per year for four years. The headline Incapacity Benefit figures have a very loose relationship with health impact of low back pain. Around 30,000 people per year make the transition to claiming long term Incapacity Benefit from claiming short term Incapacity Benefit.

Incapacity Benefit figures are of little utility in assessing changes in low back pain disability. Numbers making the transition to Long Term Incapacity Benefit may be a more useful indicator.

Introduction

Chronic pain is one of the adverse outcomes in surgery for degenerative lumbar pathology (DLP). Postoperative complications as DVT, and chronic pain in pathologies as thoracotomy or breast cancer have been associated with poor control of postoperative pain.

Abstract. Introduction. Total knee replacement (TKR) aims to reduce pain and functional limitations. Despite a good outcome for many, 15–20% patients report chronic pain three months after TKR. The STAR Care Pathway is a clinically important and cost effective treatment to improve pain outcomes over 1 year for people with chronic pain at 3 months after total knee replacement surgery. The care pathway is delivered by specially trained Extended Scope Practitioners (ESPs). There is a gap between research findings and translation into practice. This work shows how the STAR trial findings were implemented into NHS practice at a single centre and the further work required to enable national implementation. Methodology. Trial findings were presented to NHS managers with a business case for an implementation pilot. Trial documentation was adapted for use in usual care using the COM-B model for behaviour change and evidence-based approaches to increase the return of postal questionnaires. Trial sites were contacted to understand their capacity to implement the intervention locally. Results. The STAR care pathway was successfully implemented into NHS practice with a screening response rate of 83%. It is now permanently part of usual care at North Bristol NHS Trust. Trial centres indicated that lack of availability of STAR trained ESPs as a barrier to implementation. The trial manual and training session were adapted for online delivery in partnership with Health Education England. Conclusion. The STAR care pathway has been successfully embedded into NHS care. A toolkit and online clinician training package enables national implementation

Abstract. Objectives. To compare the effectiveness of phonophoresis (PH) and conventional therapeutic ultrasound (US) on the functional and pain outcomes of patients with knee osteoarthritis. Methods. We conducted an electronic search through PubMed, Cochrane Central Register of Clinical Trials (CENTRAL), Web of Science (WOS), and Scopus databases. We screened the retrieved articles to include only English full-text randomized controlled trials that examined the effect of phonophoresis versus conventional therapeutic ultrasound on patients with knee osteoarthritis. Two reviewers screened, extracted the data, and independently assessed the quality of the included articles. Results. A total of five randomized controlled trials met our inclusion criteria out of 267 studies screened. Our results showed no statistically significant differences between the PH and US groups (1), (2), (3),(4), and (5). The PH group demonstrated more significant effects than the UT group in reducing VAS pain scores (P=0.009) and improving WOMAC scores, although this did not reach the level of significance (P=0.143) (5). In the long term, PH therapy was found to be superior to US in improving painless walking duration and distance VAS scores (p=0.034, 0.017) respectively, as well as walking and resting walking VAS scores (p=0.03, 0.007) respectively, which were found to be permanent (3). Conclusions. Both therapies improve pain and function. However, we suggest conducting more high-quality trials with larger sample sizes and do not recommend the use of these therapies in clinical practice due to limitations in gender selection and high risk of bias. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Background. In recent years, ‘Get It Right First Time (GIRFT)’ have advocated cemented replacements in femoral part of Total hip arthroplasty (THA) especially in older patients. However, many studies were unable to show any difference in outcomes and although cemented prostheses may be associated with better short-term pain outcomes there is no clear advantage in the longer term. It is not clear when and why to do cemented instead of cementless. Aim. To assess differences in patient reported outcomes in uncemented THAs based on patient demographics in order to decide when cementless THA can be done safely. Method. Prospective data collection of consecutive 1079 uncemented THAs performed for 954 patients in single trust between 2010 and 2020. Oxford Hip Score (OHS) and complications were analysed against demographic variables (age, sex, BMI, ASA) and prosthesis features (femoral and acetabular size, offset and acetabular screws). Results. The mean pre-operative OHS was 14.6 which improved to 39.0 at 1 year follow up (P Value=0.000). There was no statistically significant difference between OHS outcome in patients aged over 70 versus younger groups. With a small number of revisable complications increase with age from 50s upwards. Male patients’ OHS score was on average 2.4 points higher than women. Men, however were 2.9 times more likely to experience fractures and high offset hips were 2.5 times more likely to experience dislocations. DAIR, intraoperative calcar fractures, post-operative fractures and dislocations were not associated with worse OHS. Patients with increased BMI had worse pre and post-operative hip functions yet, there was a significant multivariate association between increased BMI and increased improvement in OHS from pre-op to 1 year in women aged 55–80 and men under the age of 60. Femoral stem size increases with age but decreases in male patients over 80. There was no difference found in OHS between bilateral hip replacements and unilateral, nor was there any change found with laterality side of the replacement. Conclusions. This study suggests that ageing >70 is not associated with poorer outcomes despite small number of revisable complication rates that increase with age from 50 upwards. Men had marginally higher average OHS than women At 1 year. Higher BMI or ASA scores are associated with worse pre-operative hips and worse final outcome score. Despite this, the Delta OHS increases with increased BMI shown in the 55–80 year old female patients and male patients under 60. Key Words: THR, Uncemented, Oxford hip score, outcome

Background. Serious traumatic injury is a leading cause of death and disability globally, with the majority of survivors developing chronic pain. Methods. The aims of this study were to describe early predictors of poor long-term outcome for post-trauma pain. We conducted a prospective observational study, recruiting patients admitted to a Major Trauma Centre hospital in England within 14 days of their injuries, and followed them for 12 months. We defined a poor outcome as Chronic Pain Grade ≥ II and measured this at both 6-months and 12-months. A broad range of candidate predictors were used, including surrogates for pain mechanisms, quantitative sensory testing, and psychosocial factors. Univariate models were used to identify the strongest predictors of poor outcome, which were entered into multivariate models. Results. 124 eligible participants were recruited. At 6-months, 19 (23.2%) of 82 respondents reported a good outcome, whereas at 12-months 27 (61.4%) of 44 respondents reported a good outcome. The multivariate model for 6-months produced odds ratios for a unit increase in: number of fractures, 3.179 (0.52 to 19.61); average pain intensity, 1.611 (0.96 to 2.7); pain extent, 1.138 (0.92 to 1.41) and post-traumatic stress symptoms, 1.044 (0.10 to 1.10). At 12-months, equivalent values were: number of fractures, 1.653 (0.77 to 3.55); average pain intensity, 0.967 (0.67 to 1.40); pain extent, 1.062 (0.92 to 1.23) and post-traumatic stress symptoms, 1.025 (0.99 to 1.07). Conclusion. A poor long-term pain outcome from musculoskeletal traumatic injuries can be predicted by measures recorded within days of injury. Conflicts of interest: No conflicts of interest. Sources of funding: This study was funded by the National Institute for Health Research (NIHR) Surgical Reconstruction and Microbiology Research Centre (SRMRC)

Thoracic hyperkyphosis (TH – Cobb angle >40°) is correlated with rotator cuff arthropathy and associated with anterior tilting and protraction of scapula, impacting the glenoid orientation and the surrounding musculature. Reverse total shoulder arthroplasty (RTSA) is a reliable surgical treatment for patients with rotator cuff arthropathy and recent literature suggests that patients with TH may have comparable range of motion after RTSA. However, there exists no study reporting the possible link between patient-reported outcomes, humeral retroversion and TH after RTSA. While the risk of post-operative complications such as instability, hardware loosening, scapular notching, and prosthetic infection are low, we hypothesize that it is critical to optimize the biomechanical parameters through proper implant positioning and understanding patient-specific scapular and thoracic anatomy to improve surgical outcomes in this subset of patients with TH. Patients treated with primary RTSA at an academic hospital in 2018 were reviewed for a two-year follow-up. Exclusion criteria were as follows: no pre-existing chest radiographs for Cobb angle measurement, change in post-operative functional status as a result of trauma or medical comorbidities, and missing component placement and parameter information in the operative note. As most patients did not have a pre-operative chest radiograph, only seven patients with a Cobb angle equal to or greater than 40° were eligible. Chart reviews were completed to determine indications for RTSA, hardware positioning parameters such as inferior tilting, humeral stem retroversion, glenosphere size/location, and baseplate size. Clinical data following surgery included review of radiographs and complications. Follow-up in all patients were to a period of two years. The American Shoulder and Elbow Surgeons (ASES) Shoulder Score was used for patient-reported functional and pain outcomes. The average age of the patients at the time of RTSA was 71 years old, with six female patients and one male patient. The indication for RTSA was primarily rotator cuff arthropathy. Possible correlation between Cobb angle and humeral retroversion was noted, whereby, Cobb angle greater than 40° matched with humeral retroversion greater than 30°, and resulted in significantly higher ASES scores. Two patients with mean Cobb angle of 50° and mean humeral retroversion 37.5° had mean ASES scores of 92.5. Five patients who received mean humeral retroversion of 30° had mean lower ASES scores of 63.7 (p < 0 .05). There was no significant correlation with glenosphere size or position, baseplate size, degree of inferior tilting or lateralization. Patient-reported outcomes have not been reported in RTSA patients with TH. In this case series, we observed that humeral stem retroversion greater than 30° may be correlated with less post-operative pain and greater patient satisfaction in patients with TH. Further clinical studies are needed to understanding the biomechanical relationship between RTSA, humeral retroversion and TH to optimize patient outcomes

Abstract. Objective. Meta-analysis of clinical trials highlights that non-operative management of degenerative knee meniscal tears is as effective as surgical management. Surgical guidelines though support arthroscopic partial meniscectomy which remains common in NHS practice. Physiotherapists are playing an increasing role in triage of such patients though it is unclear how this influences clinical management and patient outcomes. Methods. A 1-year cohort (July 2019–June 2020) of patients presenting with MRI confirmed degenerative meniscal tears to a regional orthopaedic referral centre (3× ESP physiotherapists) was identified. Initial clinical management was obtained from medical records alongside subsequent secondary care management and routinely collected outcome scores in the following 2-years. Management options included referral for surgery, conservative (steroid injection and rehabilitation), and no active treatment. Outcome scores collected at 1- and 2-years included the Forgotten Joint Score-12 (FJS-12) questionnaire and 0–10 numerical rating scales for worst and average pain. Treatment allocation is presented as absolute and proportional figures. Change in outcomes across the cohort was evaluated with repeated measures ANOVA, with Bonferroni correction for multiple testing, and post-hoc Tukey pair-wise comparisons. As treatment decision is discrete, no direct contrast is made between outcomes of differing interventions but additional explorative outcome change over time evaluated by group. Significance was accepted at p=0.05 and effect size as per Cohen's values. Results. 81 patients, 50 (61.7%) male, mean age 46.5 years (SD13.13) presented in the study timeframe. 32 (40.3%) received conservative management and 49 (59.7%) were listed for surgery. Six (18.8%) of the 32 underwent subsequent surgery and nine of the 49 (18.4%) patients switched from planned surgery to receiving non-operative care. Two post-operative complications were noted, one cerebrovascular accident and one deep vein thrombosis. The cohort improved over the course of 2-years in all outcome measures with improved mean FJS-12 (34.36 points), mean worst pain (3.74 points) average pain (2.42 points) scores. Overall change (all patients) was statistically significant for all outcomes (p<0.001), with sequential year-on-year change also significant (p<0.001). Effect size of these changes were large with all Cohen-d values over 1. Controlling for age and BMI, males reported superior change in FJS-12 (p=0.04) but worse pain outcomes (p<0.03). Further explorative analysis highlighted positive outcomes across all surgical, conservative and no active treatment groups (p<0.05). The 15 (18%) patients that switched between surgical and non-surgical management also reported positive outcome scores (p<0.05). Conclusion(s). In a regional specialist physiotherapy-led soft tissue knee clinic around 60% of degenerative meniscal tears assessed were referred for surgery. Over 2-years, surgical, non-operative and no treatment management approaches in this cohort all resulted in clinical improvement suggesting that no single strategy is effective in directly treating the meniscal pathology, and that perhaps none do. Clinical intervention rather is directed at individual symptom management based on clinical preferences. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. Introduction. Adverse reactions to pain medication and pain can delay discharge after outpatient knee arthroplasty (TKA). Pharmacogenomics is an emerging tool that might help reduce adverse events by tailoring medication use based on known genetic variations in the CYP genes determining drug metabolism. This study was undertaken to evaluate whether pre-operative pharmacogenomic testing could optimize peri-operative pain management in patients undergoing total knee arthroplasty (TKA). Methods. This prospective, randomized study was performed in adults undergoing primary TKA. Patients in the experimental group underwent pre-operative pharmacogenomic evaluation and medication adjustments. Medications were not optimized for control patients. The Overall Benefit of Analgesic Score (OBAS) at 24 hours post-op was the primary outcome. Postoperative pain scores (VAS scale), total opioid use, time in recovery, and time to discharge were also compared. Results. 76 patients enrolled. 93% of patients had a poor-intermediate phenotype for at least one of four CYP genes. OBAS did not differ significantly between the two groups (4.2 control vs. 4.7 experimental; 95% CI −1.1 to 2.1) and was below the minimum clinically important difference of 2.0 points. Furthermore, there were no differences in any OBAS subscale including pain, satisfaction, or nausea. There were no differences in time in the recovery area or to discharge from hospital, or narcotic use. Conclusions. Despite many patients having a poor-intermediate phenotype for a CYP gene, pharmacogenomic testing prior to TKA and medication adjustment did not improve anesthesia or pain management outcomes, time to discharge or mean total opioid use after surgery

Introduction. Achieving a well-balanced midflexion and flexion soft tissue envelope is a major goal in Total Knee Arthroplasty (TKA). The definition of soft tissue balance that results in optimal outcomes, however, is not well understood. Studies have investigated the native soft tissue envelope in cadaveric specimen and have shown loosening of the knee in flexion, particularly on the lateral side. These methods however do not reflect the post TKA environment, are invasive, and not appropriate for intra-operative use. This study utilizes a digital gap measuring tool to investigate the impact of soft tissue balance in midflexion and flexion on post-operative pain. Methods. A prospective multicenter multi-surgeon study was performed in which patients underwent TKA with a dynamic ligament-balancing tool in combination with a robotic-assisted navigation platform. All surgeries were performed with APEX implants (Corin Ltd., USA) using a variety of tibia and femur first techniques. Gap measurements were acquired under load (average 80 N) throughout the range of motion during trialing with the balancing tool inserted in place of the tibial trial. Patients completed KOOS pain questionnaires at 3months±2weeks post-op. Linear correlations were investigated between KOOS pain and coronal gap measurements in midflexion (30°–60°) and flexion (>70°). T-tests were used to compare outcomes between categorical data. Results. 92 patients underwent TKA and completed questionnaires, with an average age of 68±9 years, 51% left and 57% female. No significant correlations were found between the medial and lateral gap size in midflexion or flexion and post-operative pain. Significant correlations were found between the absolute difference in the medial and lateral gaps in midflexion (r=−0.3, p=0.005) and flexion (r=−0.27, p=0.01) indicating knees with a more balance soft tissue profile reported improved pain outcomes at 3-months. Knees with less than 1mm difference in ML gap reported improved pain scores compared to those with greater gap differences in flexion (Δ=6.6, p=0.03). A significant correlation was found between the difference in average gaps in midflexion and flexion, and post-op pain (r=0.22, p=0.04) in which knees that were looser in flexion than midflexion reported improved pain outcomes. When dichotomizing these results in to looser or tighter in flexion compared to midflexion, knees that were looser reported significantly improved pain outcomes (Δ=8.2, p=0.02). Discussion and Conclusion. Improved outcomes correlated with a symmetrically balanced coronal midflexion gap and looser flexion space is consistent with the soft tissue balance of the native knee. The lack of a correlation between lateral loosening in flexion and improved outcomes may be a result of greater congruency between the femoral component and tibial insert than the native knee, preventing medial pivot lateral posterior condyle rollback motion. These results indicate that targeting the native soft tissue profile may not result in optimal outcomes when performing a TKA with a neutral tibial resection and an externally rotated femoral component. Further investigation is required to determine if these results hold with a larger data set and the effect on functional outcomes at both 3-months and longer follow-up periods. For any figures or tables, please contact authors directly

Robotic and navigated TKA procedures have been introduced to improve component placement precision for the purpose of improving implant survivorship and other clinical outcomes. Although numerous studies have shown enhanced precision in placing components, adoption of technology-assistance (TA) for TKA has been relatively slow. One reason for this has been the difficulty in demonstrating the cost-effectiveness of implementing TA-TKA systems and assessing their impact on revision rates. In this study, we aimed to use a simulation approach to answer the following questions: (1) Can we determine the distribution of likely reductions in TKA revision rates attributable to TA-TKA in an average US patient population? And, (2) What reduction in TKA revision rates are required to achieve economic neutrality?. In a previous study, we developed a method for creating large sets of simulated TKA patient populations with distributions of patient-specific factors (age at index surgery, sex, BMI) and one surgeon-controlled factor (coronal alignment) drawn from registry data and published literature. Effect sizes of each factor on implant survival was modeled using large clinical studies. For 10,000 simulated TKA patients, we simulated 20,000 TKA surgeries, evenly split between groups representing coronal alignment precisions reported for manual (±3°) and TA-TKA (±1.0°), calculating the patient-specific survival curve for each group. Extending our previous study, we incorporated the probability of each patient's expected survival into our model using publicly available actuarial data. This allowed us to calculate a patient-specific estimate of the Reduction in Lifetime Risk of Revision (RLRR) for each simulated patient. Our analysis showed that 90% of patients will achieve an RLRRof 1.5% or less in an average US TKA population. We then conducted a simplified economic analysis with the goal of determining the net cost of using TA-TKA per case when factoring in future savings by TKA revision rates. We assumed an average cost of revision surgery to be $75,000 as reported by Delanois (2017) and an average added cost incurred by TA-TKA to be $6,000 per case as reported by Antonis (2019). We estimate the net cost per TA-TKA case (CNet) to be the added cost per TA-TKA intervention (CInt), less the cost of revision surgery (CRev) multiplied by the estimated RLRR: CNet = CInt - CRev∗RLRR. We find that, under these assumptions, use of TA-TKA increases expected costs for all patients with an RLRR of under 8%. Based on these results, it appears that it would not be cost-effective to use TA-TKA on more than a small fraction of the typical US TKA patient population if the goal is to reduce overall costs through reducing revision risks. However, we note that this simulation does not consider other possible reported benefits of TA-TKA surgery, such as improved functional and pain outcome scores which may justify its use on other grounds. Alternative costs incurred by TA-TKA will be evaluated in a future study. To reach economic neutrality, TA-TKA systems either must reduce the added cost per intervention or increase RLRR by better addressing the root causes of revision

Aims

This study aimed to evaluate the relationship between hip shape and mid-term function in Perthes’ disease. It also explored whether the modified three-group Stulberg classification can offer similar prognostic information to the five-group system.

Aims

To describe outcome reporting variation and trends in non-pharmacological randomized clinical trials (RCTs) of distal tibia and/or ankle fractures.

Cite this article: Bone Joint Res 2022;11(8):514–517.

Aims

Hip and knee arthroplasty is commonly performed for end-stage arthritis. There is limited information to guide golfers on the impact this procedure will have postoperatively. This study aimed to determine the impact of lower limb arthroplasty on amateur golfer performance and return to play.

Introduction. The purpose of this study was to compare the radiographic outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA). Materials & Methods. Postoperative radiographic outcomes from 86 consecutive robotic-assisted UKAs (RAUKA group) from a single academic center 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 radiographically measured to identify outliers. Clinical results at 4–6 weeks postoperative were compared to a control cohort of total knee arthroplasty (TKA) patients from our institution. Results. When assessing the accuracy of RAUKAs, 91.6% of all alignment measurements and 99.2% of all overhang measurements were within the target range. All alignment and overhang targets were simultaneously met in 68.6% of RAUKAs. When comparing radiographic outcomes between the RAUKA and MUKA groups, statistically significant differences were identified for combined outliers in FCA (2.3% vs. 12.6%, p=0.006), FSA (17.4% vs. 50.2%, p<0.001), TCA (5.8% vs. 41.5%, p<0.001), and TSA (8.1% vs. 18.6%, p=0.023), as well as anterior (0.0% vs. 4.7%, p=0.042), posterior (1.2% vs. 13.4%, p=0.001), and medial (1.2% vs. 14.2%, p<0.001) overhang outliers. RAUKA demonstrated statistically significant improvements in pain and outcomes compared to TKA at 4–6 weeks (p<0.05). Conclusions. Robotic navigation decreases alignment and overhang outliers compared to manual UKA and improves clinical results compare to TKA in the early postoperative period. Given the association between component placement errors and revision in UKA, this strong significant improvement in accuracy is likely to improve implant survival

Aims

This study aims to answer the following questions in patients with hip osteoarthritis (OA) who underwent total hip arthroplasty (THA): are patient-reported outcome measures (PROMs) affected by the location of the maximum severity of pain?; are PROMs affected by the presence of non-groin pain?; are PROMs affected by the severity of pain?; and are PROMs affected by the number of pain locations?