Introduction. Patient satisfaction after total hip arthroplasty (THA) has been reported to be significantly better than after total knee arthroplasty (TKA). The same has been observed for the capacity to forget during daily life activities about the operated joint. Recently a new patient reported outcome score, the Forgotten Joint Score (FJS-12) a twelve item questionaire, has been used to evaluate postoperative outcome in joint arthroplasty. A better FJS-12 score was measured in THA than in TKA objectivating the intuitive feeling that the joint was more forgotten in THA than in TKA. Hypothesis. A higher preoperative FJS-12 score is the reason for a higher postoperative FJS-12 score in THA compared to TKA. Materials and methods. FJS-12 scores were prospectively collected in 75 THA and 75 TKA preoperatively and one year postoperative. Patients were stratified according to age and BMI. Effect size of treatment was calculated using the FJS-12. Results. No preoperative difference in mean (SD) FJS-12 was observed for THA (24(17) versus TKA (22(15)). The mean (SD) postoperative FJS-12 was significantly higher for THA (79(25)) than for TKA (73(22)). Effect size of treatment was 3.4 for TKA and 3.2 for THA. Mean (SD) for men in THA (89(25)) was significantly higher than for men in TKA (74(22)). Discussion. Postoperative differences in forgotten joint feeling after THA compared to TKA can not be explained by a preoperative difference. TKA is an effective surgery as measured by the effect size of treatment. Male TKA patients have worst outcome than male THA patients. This can probably be explained by mechanical or proprioceptive differences in between both types of arthroplasty

Introduction. The first VRAS TKA was performed in New Zealand in November 2020 using a Patient Specific Balanced Technique whereby VRAS enables very accurate collection of the bony anatomy and soft tissue envelope of the knee to plan and execute the optimal positioning for a balanced TKA. Method. The first 45 VRAS patients with idiopathic osteoarthritis of the knee was compared with 45 sequential patients who underwent the same TKA surgical technique using Brainlab 3 which the author has used exclusively in over 1500 patients. One and two year outcome data will be presented. Results. One year outcome dataVely Brainlab Significance Oxford 43.4 40.5 P=0.01 WOMAC 8.4 14.1P=0.02 Forgotten Joint Score 72.2 58.3 P=0.01 KOOS ADL91.3 85.8 P=0.04 Normal 83.3 74.2P =0.048 Activity Pain 8.6 18.4 P=0.009 ROM 127 124 P=0.01 Patient Satisfaction 98% 95% P=0.62 Operation again 100% 91% P=0.055 The two year data will be available for the ASM Conclusion: The one year outcome data shows a significantly better Oxford, WOMAC, Forgotten Joint score, KOOS ADL, Normal score and ROM scores and the activity pain is less compared to the authors extensive experience with Brainlab 3

Introduction. There is current debate concerning the most biomechanically advantageous knee implant systems, and there is also currently great interest in improving patient satisfaction after knee arthroplasty. Additionally, there is no consensus whether a posterior-stabilized (PS) total knee device is superior to a more congruent, cruciate-substituting, medially-stabilized device (MS). This study compared the clinical outcomes of two such devices. The primary hypothesis was that the clinical outcomes, and specifically the patient satisfaction as measured by the Forgotten Joint Score, would be better in the MS group. Methods. This prospective, randomized, blinded Level 1 study compared the outcomes of 100 patients who received a Medacta GMK PS device and 101 patients who received a Medacta GMK medially-stabilized Sphere device (Medacta Intl., Lugano, Switzerland). All patients undergoing elective primary total knee arthroplasty were eligible for participation. Institutional Review Board approval and informed consent from participants were obtained. The devices were implanted using an anatomic alignment/calipered- measured resection surgical approach. Clinical and radiographic assessments were performed preoperatively, 6 weeks, 6 months, and annually. Data were compared using T-test with a significance level of 0.05. Results. The minimum follow-up period is 2 years. There were no statistically significant differences in demographic characteristics and preoperative scores; tourniquet time was 7.24% longer for the PS group (40.28 min vs 37.56 min, P < .0086). Alignment was not different between the groups (preoperative or postoperative). There were significant differences between groups for the 1 year and 2 years postop Knee Society scores, Forgotten Joint Score, and ROM; in every case where there was a statistically significant difference, the results were better in the MS group. For example, the FJS was 65.72 in the MS group at 2 years, 54.33 in the PS group (p=0.02). The maximum active flexion at 2 years was 129.75º in the MS group, in the PS group it was 122.27º (p=0.03). Conclusion. The clinical outcomes of the MS group at 1 and 2 years, including the Forgotten Joint Score and flexion, were better statistically, and there was a statistically longer tourniquet time for the PS group. At the minimum 2-year follow-up, the results demonstrate superiority of the medially-stabilized device in terms of multiple clinical outcomes, including patient satisfaction as measured by the Forgotten Joint Score. These findings support the use of a medially-stabilized knee implant system, and support the conclusion that this design, in conjunction with an anatomic alignment, calipered-measured resection surgical technique, offers improved biomechanics and kinematics

Hip resurfacing arthroplasty (HRA) is a bone conserving alternative to total hip arthroplasty. We present the early 1 and 2-year clinical and radiographical follow-up of a novel ceramic-on-ceramic (CoC) HRA in a multi-centric Australian cohort. Patient undergoing HRA between September 2018 and April 2021 were prospectively included. Patient-reported outcome measures (PROMS) in the form of the Forgotten Joint Score (FJS), HOOS Jr, WOMAC, Oxford Hip Score (OHS) and UCLA Activity Score were collected preoperatively and at 1- and 2-years post-operation. Serial radiographs were assessed for migration, component alignment, evidence of osteolysis/loosening and heterotopic ossification formation. 209 patients were identified of which 106 reached 2-year follow-up. Of these, 187 completed PROMS at 1 year and 90 at 2 years. There was significant improvement in HOOS (p< 0.001) and OHS (p< 0.001) between the pre-operative, 1-year and 2-years outcomes. Patients also reported improved pain (p<0.001), function (p<0.001) and reduced stiffness (p<0.001) as measured by the WOMAC score. Patients had improved activity scores on the UCLA Active Score (p<0.001) with 53% reporting return to impact activity at 2 years. FJS at 1 and 2-years were not significantly different (p=0.38). There was no migration, osteolysis or loosening of any of the implants. The mean acetabular cup inclination angle was 41.3° and the femoral component shaft angle was 137°. No fractures were reported over the 2-year follow-up with only 1 patient reporting a sciatic nerve palsy. There was early return to impact activities in more than half our patients at 2 years with no early clinical or radiological complications related to the implant. Longer term follow-up with increased patient numbers are required to restore surgeon confidence in HRA and expand the use of this novel product. In conclusion, CoC resurfacing at 2-years post-operation demonstrate promising results with satisfactory outcomes in all recorded PROMS

Patient-reported outcome measures (PROMs) have failed to highlight differences in function or outcome when comparing knee replacement designs and implantation techniques. Ankle-worn inertial measurement units (IMUs) can be used to remotely measure and monitor the bi-lateral impact load of patients, augmenting traditional PROMs with objective data. The aim of this study was to compare IMU-based impact loads with PROMs in patients who had undergone conventional total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and robotic-assisted TKA (RA-TKA). 77 patients undergoing primary knee arthroplasty (29 RA-TKA, 37 TKA, and 11 UKA) for osteoarthritis were prospectively enrolled. Remote patient monitoring was performed pre-operatively, then weekly from post-operative weeks two to six using ankle-worn IMUs and PROMs. IMU-based outcomes included: cumulative impact load, bone stimulus, and impact load asymmetry. PROMs scores included: Oxford Knee Score (OKS), EuroQol Five-dimension with EuroQol visual analogue scale, and the Forgotten Joint Score. On average, patients showed improved impact load asymmetry by 67% (p=0.001), bone stimulus by 41% (p<0.001), and cumulative impact load by 121% (p=0.035) between post-operative week two and six. Differences in IMU-based outcomes were observed in the initial six weeks post-operatively between surgical procedures. The mean change scores for OKS were 7.5 (RA-TKA), 11.4 (TKA), and 11.2 (UKA) over the early post-operative period (p=0.144). Improvements in OKS were consistent with IMU outcomes in the RA-TKA group, however, conventional TKA and UKA groups did not reflect the same trend in improvement as OKS, demonstrating a functional decline. Our data illustrate that PROMs do not necessarily align with patient function, with some patients reporting good PROMs, yet show a decline in cumulative impact load or load asymmetry. These data also provide evidence for a difference in the functional outcome of TKA and UKA patients that might be overlooked by using PROMs alone

Joint registries suggest a downward trend in the use of uncemented Total Knee Replacements (TKR) since 2003, largely related to reports of early failures of uncemented tibial and patella components. Advancements in uncemented design such as trabecular metal may improve outcomes, but there is a scarcity of high-quality data from randomised trials. 319 patients <75 years of age were randomised to either cemented or uncemented TKR implanted using computer navigation. Patellae were resurfaced in all patients. Patient outcome scores, re-operations and radiographic analysis of radiolucent lines were compared. Two year follow up was available for 287 patients (144 cemented vs 143 uncemented). There was no difference in operative time between groups, 73.7 v 71.1 mins (p= 0.08). There were no statistical differences in outcome scores at 2 years, Oxford knee score 42.5 vs 41.8 (p=0.35), International Knee Society 84.6 vs 84.0 (p=0.76), Forgotten Joint Score 66.7 vs 66.4 (p=0.91). There were two revisions, both for infection one in each group (0.33%). 13 cemented and 8 uncemented knees underwent re-operation, the majority of these being manipulation under anaesthetic (85.7%), with no difference (8.3% vs 5.3%, 95% CI -2.81% to 8.89%, p = 0.31). No difference was found in radiographic analysis at 2 years, 1 lucent line was seen in the cemented group and 3 in the uncemented group (0.67% v 2.09%, 95%CI -4.1% to 1.24%, p = 0.29). We found no difference in clinical or radiographic outcomes between cemented and uncemented TKR including routine patella resurfacing at two years. Early results suggest there is no difference between cemented and uncemented TKR at 2 years with reference to survivorship, patient outcomes and radiological parameters

Source of the study: University of Auckland, Auckland, New Zealand. Unicompartmental knee arthroplasty (UKA) has benefits for patients with appropriate indications. However, UKA has a higher risk of revision, particularly for low-usage surgeons. The introduction of robotic-arm assisted systems may allow for improved outcomes but is also associated with a learning curve. We aimed to characterise the learning curve of a robotic-arm assisted system (MAKO) for UKA in terms of operative time, limb alignment, component sizing, and patient outcomes. Operative times, pre- and post-surgical limb alignments, and component sizing were prospectively recorded for consecutive cases of primary medial UKA between 2017 and 2021 (n=152, 5 surgeons). Patient outcomes were captured with the Oxford Knee Score (OKS), EuroQol-5D (EQ-5D), Forgotten Joint Score (FJS-12) and re-operation events up to two years post-UKA. A Cumulative Summation (CUSUM) method was used to estimate learning curves and to distinguish between learning and proficiency phases. Introduction of the system had a learning curve of 11 cases. There was increased operative time of 13 minutes between learning and proficiency phases (learning 98 mins vs. proficiency 85 mins; p<0.001), associated with navigation registration and bone preparation/cutting. A learning curve was also found with polyethylene insert sizing (p=0.03). No difference in patient outcomes between the two phases were detected for patient-reported outcome measures, implant survival (both phases 98%; NS) or re-operation (learning 100% vs. proficiency: 96%; NS). Implant survival and re-operation rates did not differ between low and high usage surgeons (cut-off of 12 UKAs per year). Introduction of the robotic-arm assisted system for UKA led to increased operative times for navigation registration and bone preparation, but no differences were detected in terms of component placement or patient outcomes regardless of usage. The short learning curve regardless of UKA usage indicated that robotic-arm assisted UKA may be particularly useful for low-usage surgeons

Introduction. Robotic-assisted total knee arthroplasty (TKA) has demonstrated significant benefits, including improved accuracy of component positioning compared to conventional jig-based TKA. However, previous studies have often failed to associate these findings with clinically significant improvements in patient-reported outcome measures (PROMs). Inertial measurement units (IMUs) provide a more nuanced assessment of a patient's functional recovery after TKA. This study aims to compare outcomes of patients undergoing robotic-assisted and conventional TKA in the early postoperative period using conventional PROMS and wearable sensors. Method. 100 patients with symptomatic end-stage knee osteoarthritis undergoing primary TKA were included in this study (44 robotic-assisted TKA and 56 conventional TKA). Functional outcomes were assessed using ankle-worn IMUs and PROMs. IMU- based outcomes included impact load, impact asymmetry, maximum knee flexion angle, and bone stimulus. PROMs, including Oxford Knee Score (OKS), EuroQol-Five Dimension (EQ-5D-5L), EuroQol Visual Analogue Scale (EQ-VAS), and Forgotten Joint Score (FJS-12) were evaluated at preoperative baseline, weeks 2 to 6 postoperatively, and at 3-month postoperative follow-up. Results. By postoperative week 6, when compared to conventional TKA, robotic-assisted TKA was associated with significant improvements in maximum knee flexion angle (118o ± 6.6 vs. 113o ± 5.4; p=0.04), symmetrical loading of limbs (82.3% vs.22.4%; p<0.01), cumulative impact load (146.6% vs 37%; p<0.01), and bone stimulus (25.1% vs 13.6%; p<0.01). Whilst there were no significant differences in PROMs (OKS, EQ-5D-5L, EQ-VAS, and FJS-12) at any time point between the two groups, when comparing OKS subscales, significantly more robotic-assisted TKA patients achieved an ‘excellent’ outcome at 6 weeks compared to conventional (47% vs 41%, p= 0.013). Conclusions. IMU-based metrics detected an earlier return to function among patients that underwent robotic-assisted TKA compared to conventional TKA that PROMs were unable to detect within the first six weeks of surgery

Introduction & Aims. Studies have shown that as many as 1 in 5 patients is dissatisfied following total knee replacement (TKA). There has also been a large reported disparity between surgeon and patient perception of clinical “success”. It has long been shown that surgeon opinion of procedural outcomes is inflated when compared with patient-reported outcomes. Additionally, TKA recipients have consistently reported higher pain levels, greater inhibition of function, and lower satisfaction than total hip replacement (THA) recipients. It is imperative that alternative methods be explored to improve TKA patient satisfaction. Therefore, the purpose of this study was to determine whether or not patients with a balanced TKA, as measured using intraoperative sensors, exhibit better clinical outcomes. Methods. 310 patients scheduled for TKA surgery were enrolled in a 6 center, randomized controlled trial, resulting in two patient groups: a sensor-guided TKA group and a surgeon-guided TKA group. Intraoperative load sensors were utilized in all cases, however in one group the surgeon used the feedback to assist in balancing the knee and in the other group the surgeon balanced without load data and the sensor was used to blindly record the joint balance. For this evaluation, the two groups were pooled and categorized as either balanced or unbalanced, as defined by a mediolateral load differential less than 15 lbf (previously described in literature). Clinical outcomes data were collected at 6 weeks, 6 months and 1 year post- operatively, including Knee Society Satisfaction and the Forgotten Joint Score. Using linear mixed models, these outcome measures were compared between the balanced and unbalanced patient groups. Results. Of the 310 patients, 200 were balanced and 110 were unbalanced. When correcting for pre-operative expectations, adverse events, BMI, gender and age, patients with a balanced knee exhibited greater satisfaction at 6 weeks, 6 months and 1 year (p=0.009) compared to the patients with an unbalanced knee. Similarly, the same balanced cohort of patients with a balanced knee showed a more forgotten joint (higher Forgotten Joint Score) at the same tine intervals. Conclusions. As patient reported outcomes become increasingly important for maintaining favorable hospital and provider metrics, it is imperative to find new methods to increase satisfaction levels among TKA recipients. In this study, patients with quantitatively balanced TKA had significantly better KSS satisfaction and forgotten joint scores compared to patients with unbalanced TKA. Longer-term follow-up is ongoing to determine whether these differences are sustained at two years post-surgery

Background. Robotic assistance is being increasingly utilised in the surgical field in an effort to minimise human error. In this study, we report minimum two-year outcomes and complications for robotic-assisted total hip arthroplasty. Methods. Data were prospectively collected and retrospectively reviewed between June 2011 and April 2014. Inclusion criteria were primary robotic-assisted THAs treating idiopathic osteoarthritis with ≥ 2- year follow-up. Demographics, operating time, complications, 2-year outcome scores and satisfaction, and subsequent surgeries were recorded. Results. There were 181 cases eligible for inclusion, of which 162 (89.5%) had minimum 2-year follow- up. Eighty-nine females and 73 males were included. Forty-seven cases used an anterior approach and 115 used posterior approach. Mean age was 61.2 and mean BMI was 29.8. At latest follow-up, mean Visual Analog Scale for pain was 0.7, patient satisfaction was 9.3, Harris Hip Score was 91.1, and Forgotten Joint Score was 83.1. The mean time of surgery was 76.7 min. There were three (1.9%) greater trochanteric fractures and three (1.9%) calcar fractures. Postoperative complications included deep vein thrombosis (2 cases, 1.2%), femoral stem loosening (one case, 0.6%, treated with stem revision), infection (1 case, 0.6%, treated with single stage incision and drainage), aseptic hematoma (1 case, 0.6%, treated with single stage incision and drainage), and dropfoot (1 case, 0.6%). No leg length discrepancies (LLD) or dislocations were reported. Conclusion. Robotic-assisted THA is a safe procedure with favorable short-term outcomes. In particular, the excellent Forgotten Joint Score results suggest that this procedure effectively replicates the feeling of the native hip

INTRODUCTION. The benefits of combining enhanced recovery after surgery (ERAS) interventions with an outpatient THA/TKA program are uncertain. The primary objective was to compare adverse event rate and secondly to compare pain management, functional recovery, PROMs and patients' satisfaction. METHODS. We conducted an ambidirectional single subject cohort study on 48 consecutive patients who experienced both a standard-inpatient and an ERAS-outpatient THA/TKA (contralaterally). We compared complications according to Clavien-Dindo scale and Comprehensive Complications Index (CCI), and unplanned episodes of care. Postoperative pain assessed with a numeric rating scale, opioid consumption in morphine milligram equivalents, functional recovery, patient-reported outcome measures (WOMAC, KOOS, HOOS, Forgotten Joint Score and Patient Joint Perception) and patients' satisfaction were also evaluated. RESULTS. Following the ERAS-outpatient surgery, complication rates were reduced by more than 50% (2.1 vs 4.4, p<0.001), CCI was significantly lower (12.3 vs 19.1, p<0.001), and similar unplanned episodes of care were observed (p>0.999). In the first 8 postoperative hours, perceived pain was similar (p>0.805) while opioid consumption was significantly reduced with ERAS-outpatient care (9.3 vs 26.5 MME, p<0.001). Patients walked, climbed stairs, showered, performed activities of daily living, practised sports, went back to work sooner after ERAS-outpatient surgery (p<0.001), but PROMs were similar between groups at the last follow-up (p> 0.188). Patients were more satisfied with hospital stay, pain management, functional recovery, wound management, and overall experience of the ERAS-outpatient pathway and recommended it significantly more (p <0.002). DISCUSSION. Most studies comparing outpatient to inpatient programs conclude that outpatient surgeries did not increase complication or readmission rates, and, overall, were not inferior. We found that compared to std-inpatient practice, ERAS-outpatient program reduced complications by half while not resulting in more unplanned episodes of care. Moreover, it resulted in similar pain relief with fewer opioids, faster early functional recovery and higher satisfaction. Patients were significantly more inclined to recommend the ERAS-outpatient pathway after having personally experienced both outpatient and inpatient protocols. These finding are likely multifactorial and linked to the specific ERAS interventions. CONCLUSION. Results of this study highlight the importance of following ERAS principles when implementing an outpatient THA/TKA program

Introduction. The use of technology, such as navigation and robotic systems, may improve the accuracy of component positioning in total hip arthroplasty (THA) but its impact on patient reported outcomes measures (PROMs) remains unclear. This study aims to identify the association between intraoperative use of technology and patient reported outcomes measures (PROMs) in patients who underwent primary total hip arthroplasty (THA). Methods. We retrospectively reviewed patients who underwent primary THA between 2016 and 2020 and answered a post-operative PROM questionnaire. Patients were separated into three groups depending on the technology utilized intraoperatively: navigation, robotics, or no technology (i.e. manual THA. The Forgotten Joint Score (FJS-12) and Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS, JR) were collected at various time points (FJS: 3m, 1y, and 2y; HOOS, JR: pre-operatively, 3m, and 1y). Demographic differences were assessed with chi-square and ANOVA. Mean scores between all groups were compared using univariate ANCOVA, controlling for observed demographic differences. Results. Of the 1,960 cases included, 896 navigation, 135 robotics, and 929 manual. There was a significant statistical difference in one-year HOOS, JR scores (85.23 vs. 85.95 vs. 86.76; p=0.014) and two-year FJS-12 scores (64.72 vs. 73.35 vs. 74.63; p=0.004) between the three groups. However, they did not exceed the mean clinically important difference (MCID) at any time period. Short and long-term PROMs significantly differed between navigation and manually performed cases (FJS 3m: p=0.047; FJS 2y: p=0.001; HOOS, JR 1y: p=0.004). Two-year FJS-12 scores statistically differed between navigation and robotics (p=0.038). There was no statistical difference in either FJS-12 or HOOS, JR scores between robotics and manual THA groups at all time points (FJS 3m:p=0.076, 1y:p=0.225, 2y:p=0.793; HOOS, JR preop:p=0.872, 3m:p=0.644, 1y:p=0.531). Conclusion. Statistical differences observed between all modalities are not likely to be clinically meaningful with regards to early patient reported outcomes. While intraoperative use of technology may improve the accuracy of implant placement, these modalities have not necessarily translated into improved early reported functional outcomes

Background. Total hip arthroplasty (THA) has been and continues to be the gold standard for treatment of end-stage osteoarthritis. With each year, implant characteristics are evolving to increase patient-reported outcomes and decrease complications. Purpose: to report minimum 2-year outcomes and complications in patients who underwent robotic-arm assisted THA using Corin versus Stryker-type implants. Methods. Data were prospectively collected on patients who underwent THA with Corin-type implants (both cup and stem) and THA using Stryker implants between June 2011 and July 2016. A 1:1 propensity match was performed using the following 5 covariates: age, body mass index, gender, Charlson score and smoking status. Surgical outcomes were assessed at minimum 2-year follow-up using the Forgotten Joint Score (FJS), Harris Hip Score (HHS), Veterans RAND 12-item physical and mental health survey, Short Form 12 physical and mental health survey, Visual Analog Score (VAS), and patient satisfaction. The exclusion criteria were previous hip condition/surgery, workers compensation, or were unwilling. Results. Of the eligible 774 cases, 645 patients (83.3%) had minimum 2-year follow-up and met inclusion and exclusion criteria. Of the 645 patients, 323 had Corin implants, and 155 had Stryker implants. The 1:1 propensity match successfully yielded 290 patients (145 per implant group) which had a minimum 2-year follow-up at a mean 38.3 months (range, 24.1–65.3 months). Average age was 59.9 (range, 34.92–79.89 Stryker group, 30.65–75.92 Corin group) for each group and average BMI were 30.0 (range, 19.05–49.33) kg/m. 2. for the Stryker group and 29.77 (range, 20.15–55.37) kg/m. 2. for the Corin group. FJS (P=0.0388) and patient satisfaction (P=0.0019) were significantly higher in the Stryker implant group than the Corin implant group. There were nine cases of postoperative thigh numbness or paresthesias, three cases of wound infection, and one case of nonunion in the Corin-implant group. There were four cases of postoperative thigh numbness or parasthesias and six cases of wound infection in the Stryker-implant group. Conclusion. At minimum 2-year follow-up, patients who had undergone THA with Stryker-type implants had significantly higher FJS and satisfaction and a trend toward decreased complications than patients with Corin-type implants. These results can help guide decision making for surgical instrumentation by arthroplasty surgeons

Assessing patients' functional outcomes following total hip arthroplasty with traditional scoring systems is limited by their ceiling effects. The Forgotten Joint Score (FJS) has been suggested as a more discriminating option. The actual score in the FJS which constitutes a “forgotten joint”, however, has not been defined. The emerging concept of joint perception led to the development of the Patient's Joint Perception question (PJP) to assess the patient's opinion of their prosthetic joint. Two hundred fifty-seven THAs were assessed at a mean of 68 months follow-up (range 57–79). Outcomes included the WOMAC, FJS and the PJP. Correlation of the scores as well as the ceiling effects were analysed. The mean FJS was 88.5 (range 27.1–100). PJP was correlated with the FJS and WOMAC (Spearman's rho: −0.510 and 0.465 respectively). Fifty-two percent of the patients felt their hip as a natural joint (FJS CI 95% 93.3–96), 24.1% as an artificial joint with no restriction (FJS CI 95% 83.1–90.5), and 23.3% as an artificial joint with minor restrictions (FJS CI 95% 73.8–82.2). Only 0.8% had major restrictions and none reported a non-functional joint. The ceiling effect was high with both the WOMAC and FJS, with 27.2% and 31.9%. In addition, 28.6% of the patients had a WOMAC >10 and 23.4% a FJS of < 9 0 while reporting having a natural hip. Furthermore, 21.5% with a perfect WOMAC or 21.9% with a perfect FJS, reported having an artificial joint with or without limitation. A forgotten hip perception corresponds to a FJS >93. In 20–30% of the cases, the WOMAC and FJS failed to identify the forgotten joint, or reached the maximum score when the patients did not feel their hip was natural. The PJP is a simple and reliable tool that enables identification of patients that feel their hip is natural

Background. Assessing patients’ functional outcomes following total knee arthroplasty (TKA) with traditional scoring systems is limited by their ceiling effects. The Forgotten Joint Score (FJS) has been suggested as a more discriminating option. The actual score in the FJS which constitutes a “forgotten joint,” however, has not been defined. The emerging concept of joint perception led to the development of the Patient's Joint Perception question (PJP) to assess the patient's opinion of their prosthetic joint. Methods. 101 TKA were assessed at a mean of 41 months of follow-up (range 29=51). Outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), FJS, and PJP. Correlation of the scores as well as the ceiling effects were analyzed. Results. The mean FJS was 79.0 (range 0=100). PJP was correlated with the FJS and WOMAC (Spearman's rho −0.720 and 0.684, respectively). 34% of the patients felt their prosthetic knee as a natural joint (FJS: 95% confidence interval [CI] 92.2–97.9), 15% as an artificial joint with no restriction (FJS: 95% CI 69.6–93.5), and 40% as an artificial joint with minor restrictions (FJS: 95% CI 65.4–78.3). 11% had major restrictions and none reported a non-functional joint. The ceiling effect was high with both the WOMAC and FJS, where 17% and 18% achieved the maximal score respectively. In addition, 13% of the patients had a WOMAC >10 and 22% an FJS < 90 while reporting having a natural knee. Furthermore, 19% with a perfect WOMAC reported having an artificial joint with or without limitation. Conclusion. With a TKA, a forgotten knee perception corresponds to an FJS >92. In 13%–22% of the cases, the WOMAC and FJS failed to identify the forgotten joint, or reached the maximum score when the patients did not feel their knee was natural. The PJP is a simple and reliable tool that enables identification of patients who feel replaced knee is natural

Background:. Custom cutting guides (CCG) in total knee arthroplasty (TKA) use preoperative 3-dimensional imaging to fabricate cutting blocks specific to a patient's native anatomy. To date, small cohorts and short follow-up have limited reports studying clinical and functional outcomes of CCGs versus standard intramedullary and extramedullary alignment instrumentation. The purpose of this study was to determine if CCGs improve clinical outcomes versus standard alignment guides following TKA at a mean of 2 years postoperatively. Methods:. This was a prospective cohort study of a consecutive series of patients undergoing primary TKA using the same cruciate-retaining, cemented system between January 2009 and April 2012. Exclusion criteria were patients with prior open knee surgery, a flexion contracture of greater than 20 degrees, a distal femoral or proximal tibial defect requiring a metal or allograft augment, the use of either femoral or tibial stem extensions, or a contraindication to obtaining a magnetic resonance imaging (MRI) scan. All patients were offered the option of receiving a preoperative MRI and TKA with CCGs, and each patient self-selected for either the CCG or standard cohort. The first 95 patients that selected CCGs were compared with the first 95 that were performed with standard instrumentation. The alignment goal for all TKAs was a hip-knee-ankle (HKA) angle of 0 degrees with the femoral and tibial components aligned perpendicular to the mechanical axis. University of California at Los Angeles (UCLA), Short Form-12 (SF-12), and Oxford Knee scores were collected preoperatively. These scores, along with the Forgotten Joint score and a questionnaire assessing patient satisfaction and residual symptoms, were administered at most recent follow-up. Postoperative, rotationally controlled coronal scout CT scans were used to measure the overall hip-knee-ankle (HKA) alignment. Perioperative complications occurring within 6 months of the index procedure were reviewed. Independent samples t-tests and Chi-square tests were used, with a p-value <0.05 considered significant. Results:. 95 patients in the standard (mean follow-up 2.5 ± 1.1 years) and 95 patients in the CCG (mean follow-up 2.2 ± 1.0 years) cohorts were analyzed. There was no difference in mean age (p=0.48), BMI (p=0.19), mean tourniquet time (59.1 ± 13.2 minutes in CCG v 59.7 ± 14.7 minutes in standard; p=0.75) or percentage of outliers for HKA alignment (23% in standard versus 31% in CCG with HKA outside of 0 ± 3 degrees; p=0.2) between the two cohorts. However, CCG patients did have increased UCLA (p=0.03), SF-12 physical (p=0.001) and Oxford knee scores (p=0.001) preoperatively. At the most recent follow-up, no differences were present for range of motion, UCLA, SF-12, Oxford Knee, or Forgotten Joint scores between the two cohorts (p=0.09 v 0.76). In addition, no differences were present for the incremental improvement in these scores from preoperatively to postoperatively (p=0.1 v 0.9). Patient satisfaction and the presence of residual symptoms were similar (p=0.1 v 0.8), with only 66.3% of standard patients and 67.6% of CCG patients noting their knee to feel “normal” or comparable to their nonoperative knee (p=0.7). After excluding 5 superficial wound complications in the standard cohort caused by use of a subcutaneous braided suture, no differences in overall or knee related complications were appreciated between the two cohorts (p=0.5 v 0.65). Conclusions:. At a mean follow-up of greater than 2 years, CCGs fail to demonstrate any advantages in clinical outcomes versus the use of standard instrumentation in TKA. The clinical benefit of CCGs must be proven prior to continued implementation of this technology

Introduction. Patients-reported outcome measures (PROMs) have been reported as the important methods to evaluate clinical outcomes in total knee arthroplasty (TKA). The patient satisfaction score in Knee Society Score (KSS-2011) has been used in the recent literatures. Patient satisfaction was subjective parameter, and would be affected by multiple factors including psychological factors and physical conditions at not only affected joint but also elsewhere in the body. The question was raised regarding the consistency of patient satisfaction score in KSS-2011 to other PROMs. The purpose of this study was to investigate the correlation of patient satisfaction in KSS-2011 to other categories in KSS-2011 and to other PROMs including Forgotten Joint Score (FJS-12), EuroQol-5 Dimensions (EQ-5D) and 25-questions in Geriatric Locomotive Function Scale (GLFS-25). Material & Method. 83 patients over 65 years old with osteoarthritic knees were involved in this study. All patients underwent CR-TKAs (Persona CR. R. ). The means and ranges of demographics were as follows: age; 74.5 years old (65–89), Hip-Knee-Ankle (HKA) angle; 12.4 (−6.2–22.5) in varus. We asked patients to fulfill the questionnaire including KSS-2011, FJS-12, EQ-5D and GLFS-25 at 1-year postoperative follow-up visit. KSS-2011 consisted of 4 categories of questions; patient satisfaction (PS), symptoms, patient expectations (PE), functional activities (FA). We evaluated the correlation of PS to other PROMs using simple linear regression analyses (p<0.001). Results. The means and standard deviations of 1-year postoperative scores were as follows: PS; 28.5 ± 7.0, symptoms; 19.1 ± 4.3, PE; 11.2 ± 2.9, FA; 71.5 ± 16.6, FJS-12; 51.5 ± 18.6, EQ5D; 0.69 ± 0.10, GLFS-25; 25.7 ± 16.9. PSs were moderately positively correlated to other categories in KSS-2011(correlation coefficient (r): symptoms; 0.69, PE; 0.73, FA; 0.69). PSs were positively correlated to both FJS-12 and EQ5D (r: FJS-12; 0.72, EQ-5D; 0.67) and negatively correlated to GLFS-25(r; −0.74). Discussions. Patient satisfaction score positively correlated to the symptoms, patient expectation and functional activities in KSS-2011 with moderately high correlation coefficient. This meant the better pain relief and functional outcome improved patient satisfaction. Although there had be reported preoperative higher expectation would lead to poor patient satisfaction postoperatively, we interestingly found positive correlation between patient satisfaction and expectation at 1 year after TKA. Patient with the higher satisfaction tended to expect more in the future, on the other hand, unsatisfied patient with residual pain and/or poor function would resign themselves to the present status and reduced their expectation in our patient population. We have found patient satisfaction score in KSS-2011 significantly correlated to FJS-12 and GLFS-25 with strong correlation coefficient. This meant patient satisfaction could be considered consist to other PROMS in relatively younger patient with better functional status in this study. Conclusion. The patient satisfaction score in KSS-2011 was found to be consistent with moderately high correlations coefficient to other categories in KSS-2011 and other PROMs including FJS-12, EQ-5D, GLFS-25 at 1 year after (CR)-TKA. For any figures or tables, please contact authors directly

INTRODUCTION. Medial ball and socket knee designs have a long history but are not yet widely used. The Saiph medial ball and socket knee passed preclinical testing before an introductory cohort of 20 patients were studied in detail for 2 years. Subsequently a multicenter study was undertaken by the developing surgeons. METHODS. We report the minimum 5-year follow-up of the first 102 Saiph knee replacements implanted in Australia as part of a step-wise or phased introduction of this device to the market. These 102 consecutive patients were recruited to the study at two centers in Australia. Revisions, complications and adverse events were collected. Patient reported scores including EQ-5D, Oxford Knee Score (OKS), Knee Injury and Osteoarthritis Outcome Score (KOOS) and Kujala and range of motion satisfaction and forgotten joint score were collected. Data were collected pre-operatively and at one to two years post-operatively and at a minimum of five years. RESULTS. The average age of the patients was 67.2 years (range, 47 to 85) and average BMI was 29. There were 53% female and 47% male patients. There were two revisions performed – one for infection and one for arthrofibrosis. There were no device related failures or adverse events reported. The OKS improved from 21 pre-operatively to 43 post-operatively. KOOS improvement pre-operative to post-operative was 51 to 88 (symptoms), 54 to 94 (pain), 14 to 68 (sport) and 23 to 86 (quality of life). The percentage of patients reporting difficulty negotiating stairs because of their knee decreased from 86% pre-operatively to 5% post-operatively. The percentage of patients reporting a moderate or severe lack of confidence with their knee decreased from 91% pre-operatively to 10% post-operatively. CONCLUSION. This study demonstrates that this knee replacement design is safe and provides early pain relief and improved function. Patient reported outcome scores which improved post-operatively and were maintained at latest follow-up. Further data is being collected as part of a large, multicenter study to show repeatability in non-designer surgeon hands

Introduction. Mid-flexion stability is believed to be an important factor influencing successful clinical outcomes in total knee arthroplasty. The post of a posterior-stabilizing (PS) knee engages the cam in >60° of flexion, allowing for the possibility of paradoxical mid-flexion instability in less than 60° of flexion. Highly-conforming polyethylene insert designs were introduced as an alternative to PS knees. The cruciate-substituting (CS) knee was designed to provide anteroposterior stability throughout the full range of motion. Methods. As part of a prospective, randomized, five-year clinical trial, we performed quantitative stress x-rays on a total of 65 subjects in two groups (CS and PS) who were more than five years postoperative with a well-functioning total knee. Antero-posterior stability of the knee was evaluated using stress radiographs in the lateral position. A 15 kg force was applied anteriorly and posteriorly with the knee in 45° and 90° of flexion. Measurements of anterior and posterior displacement were made by tracing lines along the posterior margin of the tibial component and the posterior edge of the femoral component, which were parallel to the posterior tibial cortex. (Figures 1–4). Results. In both 45° and 90° of flexion, the PS group demonstrated significantly less total anterior/posterior displacement compared to the CS group, (45°: 7.33 mm vs 12.44 mm, p ≤ 0.0001, 90°: 3.54 mm vs. 9.74 mm, p ≤ 0.0001). (Figures 5,6) The only statistically significant outcomes score difference was seen with the KSS function score in the female subset, with the CS score lower (81.8) compared to the PS score (94.7). (Figure 7) All of the other scores, KSS pain/motion and KSS function scores, as well as the LEAS and FJS scores, were all similar statistically, as was the range of motion and the long axis x-ray alignment. Discussion & Conclusion. The post and cam posterior-stabilized knee has traditionally been thought to be the best choice for providing stability for knee replacement with PCL-insufficiency or sacrifice. However, this difference in stability as measured with stress xrays did not correlate with any detectible differences in any of the clinical outcomes measurements collected (Knee Society Score, Forgotten Joint Score, Lower Extremity Activity Scale) or in the range of motion or coronal alignment, with the exception of the female subgroup KSS function score. In summary, the CS knee demonstrates greater total antero-posterior laxity compared to the PS knee, as measured by stress radiographs, but there is not a strong correlation with clinical outcomes measurements. A greater number of subjects and/or a younger, higher demand population studied with this protocol might produce greater differences in the outcomes, especially in the FJS score. For any figures or tables, please contact the authors directly

Surgeons have widely disparate views on how to improve outcomes for patients following total knee arthroplasty. Over the past decade we have witnessed a remarkable transformation of the entire process of care surrounding total knee arthroplasty. The entirety of the patient experience after contemporary total knee replacement in 2015 is markedly different from that encountered by patients just a decade ago. Ten years ago most patients were treated in a traditional sick-patient model of care and because they were assumed to require substantial hospital intervention, many cumbersome and costly interventions (e.g. indwelling urinary catheters, patient-controlled-analgesic pumps, autologous blood transfusion, continuous passive motion machines) were a routine part of the early postoperative experience. Today the paradigm has shifted to a well-patient model with a working assumption that once a patient has been medically optimised for surgery then the intervention itself, knee replacement, will not typically create a sick-patient. Instead it is expected that most patients can be treated safely and more effectively with less intensive hospital intervention. While as orthopaedic surgeons we are enamored with the latest surgical techniques or interesting technologies most busy surgeons recognise that advances in perioperative pain management, blood management, and early-mobilization therapy protocols account for the greatest share of improvements in patient experience over the past decade. With that paradigm shift in the hospital/surgical part of the total knee experience comes renewed interest and emphasis on function after TKA. Most surgeons are well aware of a “satisfaction gap” between the results of total hip replacement and total knee replacement. While studies report varying percentages (based on the definition of satisfaction and particular patient populations) what is clear is that 10–20% of patients are not fully satisfied after knee replacement. Researchers have highlighted some of this discordance with the introduction of the Forgotten Joint Score. These researchers and others can consistently point to higher satisfaction or fewer residual symptoms in patients who have undergone hip arthroplasty versus knee arthroplasty. What is also interesting to note, however, is that even amongst otherwise healthy control patients there are more baseline symptoms referable to the knee than to the hip. This may indicate that with knee arthroplasty we are chasing a more elusive target than is the case in hip arthroplasty. Most surgeons today would agree that alignment plays an important role in TKA function and survival, but certainly factors other than alignment are also important in determining the survival of modern total knee replacements. The evidence suggests that ideal alignment after knee replacement is probably very specific for any given patient and influenced by individual differences. There is a complex interplay between limb alignment, component rotation, sizing, ligament balance, and gait dynamics. Moving forward, more attention needs to be devoted to function in knee replacement in order to improve patient satisfaction. While the mechanical axis has been useful, future improvements are dependent on hitting better targets. The historic focus on radiographic outliers to explain total knee failures has been incomplete at best and has possibly dulled and constrained our collective intellectual curiosity