Joint awareness after unicompartmental knee arthroplasty and total knee arthroplasty: a systematic review and meta-analysis of cohort studies

Health-related quality of life after total knee arthroplasty and unicompartmental knee arthroplasty for unicompartmental osteoarthritis: A systematic review and meta-analysis

BACKGROUND

While previous research has demonstrated potential advantages of unicompartmental knee arthroplasty (UKA) over total knee arthroplasty (TKA), particularly in terms of clinical outcomes such as function and pain relief, the specific impact on health-related quality of life (HRQOL) remains unclear. This systematic review and meta-analysis aim to address this gap by comparing HRQOL outcomes between UKA and TKA, providing valuable insights for clinical decision-making.

METHODS

We conducted a literature search in the PubMed, Embase, Cochrane Controlled Register of Trials (CENTRAL), and Web of Science databases up to July 15, 2023. Eligible studies assessed HRQOL using EQ-5D, SF-36, or SF-12 and were assessed for methodological quality using the Newcastle-Ottawa Scale (NOS).

RESULTS

Seven eligible studies were included, comprising a total of 64,585 patients with 35,809 undergoing TKA and 28,776 undergoing UKA. Patient age ranged from 52.0 to 67.7 years with an average BMI ranging from 27.2 to 31.0 kg/m2. Follow-up periods ranged from 6 months to 10 years. Five studies (63,829 patients) that evaluated HRQOL using EQ-5D showed significantly better outcomes for UKA compared to TKA (MD -0.04, 95% CI -0.05 to -0.02). Two studies (756 patients) that evaluated HRQOL using SF-36 showed no significant difference between TKA and UKA. Five studies (63,286 patients) that evaluated functional outcomes using Oxford Knee Score (OKS) showed significantly better functional scores for UKA compared to TKA (MD -1.29, 95% CI -1.86 to -0.72). Four studies (24,570 patients) that reported patient satisfaction showed no statistically significant difference between TKA and UKA (MD 0.97, 95% CI 0.90 to 1.05). Further subgroup analysis did not affect the conclusions.

CONCLUSIONS

Our meta-analysis suggests that UKA is associated with better HRQOL and knee function, as well as similar patient satisfaction, compared to TKA for patients with unicompartmental osteoarthritis.

Unicompartmental knee arthroplasty improves mental health in patients with single compartment knee osteoarthritis

PURPOSE

The purpose of this study was to determine if preoperative mental health status improves following unicompartmental knee arthroplasty (UKA) in patients with single compartment knee osteoarthritis (OA).

METHODS

A total of 163 patients underwent UKA [115 (71%) medial, 48 (29%) lateral] (mean age = 65 ± 11) completed preoperative and minimum 2-year postoperative veterans RAND 12 item health survey (VR-12) mental component score (MCS). VR-12 MCS was the primary outcome measure. Secondary measures included VR-12 physical component summary score (PCS), knee osteoarthritis outcome score (KOOS) and KOOS patient acceptable symptom state at the final follow-up.

RESULTS

The median VR-12 MCS improved from 50.5 [interquartile range (IQR): 43.7-56.8] to 55.0 [IQR: 52.3-57.0] (p < 0.001) at a mean follow-up of 9.5 ± 4 years (range 2-19 years) following UKA. Preoperative VR-12 MCS was significantly correlated with patients postoperative VR-12 PCS (ρ = 0.294, p < 0.01), KOOS pain (ρ = 0.201, p = 0.012), KOOS ADL (ρ = 0.243, p = 0.002) and KOOS quality of life (ρ = 0.233, p < 0.01). Sixty-three (39%) patients improved from low VR-12 MCS (<50) to normal VR-12 MCS (≥50). One hundred forty-two (87%) achieved a normal VR-12 MCS score (≥50) postoperatively.

CONCLUSION

At a mean of 10-year follow-up, patients who underwent UKA for single compartment osteoarthritic knee pain demonstrated significant improvement in mental health scores. UKA resulted in normal mental health in a majority of patients (87%). The resultant improved mental health scores were associated with improved patient pain and activities of daily living.

LEVEL OF EVIDENCE

Level III retrospective cohort study.

The safety and efficacy of unicompartmental knee arthroplasty in outpatient surgical centers: A systematic review and meta-analysis

BACKGROUND

Unicompartmental knee arthroplasty (UKA) is an effective treatment method for knee osteoarthritis. With the development and implementation of enhanced recovery after surgery, UKA is now increasingly performed in outpatient surgical centers. However, there is ongoing debate regarding the safety and effectiveness of performing UKA in outpatient settings.

METHODS

The search was performed to retrieve randomized controlled trials and cohort studies on outpatient UKA from PubMed, Cochrane Library, EMbase, CNKI, and WanFangData databases. The search was conducted from the inception of the databases until August 31, 2023. After independent screening, data extraction, and risk of bias evaluation by two researchers, meta-analysis was performed using RevMan 5.4 software.

RESULTS

A total of eight studies involving 18,411 patients were included. The results showed that the postoperative transfusion rate in the outpatient group was lower than that in the inpatient group [OR = 0.36, 95%CI (0.24, 0.54), p < 0.00001], and the difference was statistically significant. However, there was no significant difference between the two groups in terms of readmission rate, reoperation rate, surgical site infection, and periprosthetic fracture. The differences were not statistically significant.

CONCLUSION

Compared to the traditional inpatient route, the blood transfusion rate for single-condyle replacement in the outpatient operation center is lower, and there is no significant difference in readmission rate, reoperation rate, surgical site infection, and periprosthesis fracture. The outpatient approach to UKA is safe, feasible, and highly satisfactory for patients. However, the results have certain limitations, and a rigorous preoperative complication risk assessment can minimize the risk of UKA in outpatient surgery centers.

TRIAL REGISTRATION

PROSPERO number CRD42023405373.

Comparison of joint awareness after total knee arthroplasty, medial unicompartmental knee arthroplasty, and high tibial osteotomy: a retrospective study

INTRODUCTION

This study aimed to compare the Forgotten Joint Score-12(FJS) outcomes and the minimum clinically important difference (MCID) of the FJS after high tibial osteotomy (HTO), unicompartmental knee arthroplasty (UKA), and total knee arthroplasty (TKA) with short-term follow-up (at least 2 years). Another objective of the study is to investigate the factors influencing FJS. It is hypothesized that there are differences in FJS outcomes among the three procedures.

METHODS

Patients who underwent HTO, UKA, and TKA from January 2016 to December 2020 and were followed up for a minimum of 2 years were included in the study. The FJS were analyses from a cohort of people who submitted data to two years. The preoperative and postoperative clinical outcomes were compared and evaluated the patient-related factor. The FJS scores were predicted using multiple linear regression analysis. Additionally, Patient's Joint Perception (PJP) questions were used as anchors to determine the achievement of the forgotten joint, and FJS MCID were calculated using the receiver operating characteristic curve (ROC).

RESULTS

Three hundred eighty-nine patients were included in the final study, and there were 111 patients in HTO groups,128patients in UKA groups, and 150 patients in TKA groups. The mean follow-up was 47.0 months. There was a significant difference in the total FJS, between the HTO, UKA, and TKA groups (FJS:59.38 ± 7.25, 66.69 ± 7.44 and 56.90 ± 6.85, p < 0.001. We found the MCID of the FJS of HTO, UKA, and TKA were 63.54, 69.79, and 61.45, respectively. In multiple linear regression, younger age, and higher FS were significant predictors of better FJS.

CONCLUSION

Medial UKA demonstrated lower patient awareness in comparison to HTO and TKA, as assessed by the FJS. Younger age and higher FS were identified as significant predictors of improved FJS, providing valuable guidance for surgical decision-making.

Surgical interventions for symptomatic knee osteoarthritis: a network meta-analysis of randomized control trials

BACKGROUND

Multiple surgical interventions exist for the treatment of symptomatic knee osteoarthritis, but the surgeon and patient may often have difficulty deciding which interventions are the best option.

METHODS

We conducted a systematic review to identify randomized clinical trials (RCTs) that compared complications, revisions, reoperations, and functional outcomes among TKA (total knee arthroplasty), UKA (unicompartmental knee arthroplasty), HTO (high tibial osteotomy), BCA (bicompartmental knee arthroplasty), BIU (bi-unicompartmental knee arthroplasty), and KJD (knee joint distraction). The PubMed, Embase, and Cochrane databases were reviewed for all studies comparing two or more surgical interventions. Direct-comparison meta-analysis and network meta-analysis (NMA) were performed to combine direct and indirect evidence. The risk of bias was assessed using the revised Cochrane risk of bias tool for RCTs.

RESULTS

This NMA and systematic review included 21 studies (17 RCTs), with a total of 1749 patients. The overall risk-of-bias assessment of the RCTs revealed that 7 studies had low risk, 5 had some concerns, and 9 had high risk. SUCRA (the surface under the cumulative ranking curve) rankings revealed that KJD had the greatest risk of appearing postoperative complications, revisions, and reoperations, and UKA or TKA had the lowest risk. The majority of comparisons among various treatments showed no difference for functional outcomes.

CONCLUSION

Each surgical intervention is noninferior to other treatments in functional outcomes, but UKA and TKA are better options to treat OA according to SUCRA rankings by comparing complications, revisions, and reoperations. KJD is an imperfect option for treating OA. Other treatments should be carefully considered for each patient in accordance with their actual conditions. However, this conclusion is limited by the selection of reviewed publications and individual variation of surgical indications for patients.

TRIAL REGISTRATION

This study was registered with Research Registry (reviewregistry1395).

Clinical and Functional Results of Cementless Unicompartmental Knee Arthroplasty with a Minimum Follow Up of 5 Years-A Consecutive Cohort of 201 Patients

The number of unicompartmental knee replacements (UKR) is increasing. Alongside various advantages, the revision rate of cemented UKR is higher compared to total knee arthroplasty (TKR). In contrast, cementless fixation shows reduced revision rates, compared to the cemented UKR. However, most of the recent literature is based on designer-dependent studies. In this retrospective, single-center cohort study, we investigated patients who underwent cementless Oxford UKR (OUKR) between 2012 and 2016 in our hospital with a minimum follow-up of five years. Clinical outcome was evaluated using the OKS, AKSS-O, AKSS-F, FFbH-OA, UCLA, SF-36, EQ-5D-3L, FJS, ROM, pain, and satisfaction measures. Survival analysis was performed with reoperation and revision as endpoints. We included 201 patients (216 knees) for clinical evaluation. All outcome parameters increased significantly from pre- to postoperative stages. The five-year survival rate was 96.1% for revision surgery and 94.9% for reoperation. The main reasons for revision were the progression of osteoarthritis, inlay dislocation, and tibial overstuffing. Two iatrogenic tibial fractures appeared. Cementless OUKR shows excellent clinical outcome and high survival rates after five years. The tibial plateau fracture in cementless UKR represents a serious complication and requires modification of the surgical technique.

Mobile-Bearing has no Benefit Over Fixed-Bearing Total Knee Arthroplasty in Joint Awareness and Crepitus: A Randomized Controlled Trial

BACKGROUND

Given higher component conformity, rotational availability of polyethylene insert, and more physiologic patellofemoral tracking, mobile-bearing (MB) total knee arthroplasty (TKA) is supposed to offer advantages in joint perception and crepitus. The purpose of this study was to investigate whether MB TKA offers superior outcomes over fixed-bearing (FB) TKA in terms of joint awareness and crepitus.

METHODS

This prospective, randomized, controlled trial included 49 FB and 49 MB TKAs that shared the same posterior-stabilized femoral component. Primary outcomes included joint awareness assessed with the Forgotten Joint Score and crepitus graded according to severity and sound at 3 years postoperatively. Secondary outcomes were the range of motion, the Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, component position, and joint line level on radiographs.

RESULTS

The Forgotten Joint Score showed no significant difference between the FB (67 points; range, 0-100) and MB groups (63 points; range, 13-100) (P = .440). For crepitus, no significant differences were found in the overall incidence rate (FB group, 18%; MB group, 12%; P = .386) and grade (grade 1, 6 versus 5; grade 2, 2 versus 1; grade 3, 1 versus 0, respectively). There were no significant differences in range of motion, Knee Society Score, and Western Ontario and McMaster Universities Osteoarthritis Index, as well as radiographic outcomes between the two groups (all, P > .05).

CONCLUSION

MB TKA offers no benefits in terms of joint awareness and crepitus compared with FB TKA at mean 3 years postoperatively. The theoretical advantages of MB TKA have yet to be demonstrated in practice, leaving the selection of bearing type to the surgeon's judgment.

LEVEL OF EVIDENCE

Level II.

Insufficient evidence to confirm benefits of custom partial knee arthroplasty: a systematic review

PURPOSE

The purpose of this systematic review was to synthesise the available literature and critically appraise current evidence on the functional and radiographic outcomes as well as reoperation and revision rates of custom partial knee arthroplasty, i.e., unicompartmental knee arthroplasty (UKA), bicompartmental knee arthroplasty (BKA), and patellofemoral arthroplasty (PFA).

MATERIAL AND METHODS

This systematic review was performed in accordance with the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and a protocol was registered with Prospero. On 25 May 2021, two authors independently searched and screened Level I-IV studies that reported on outcomes of custom partial knee arthroplasty using the databases of MEDLINE^®, EMBASE^®, and the Cochrane Library without restriction on date of publication. Findings from eligible articles were synthesised and tabulated, and quality assessments were done according to the guidelines of the Joanna Briggs Institute (JBI) Checklists.

RESULTS

Fifteen articles were eligible for data extraction, of which two comparative and four case series were on custom UKA (follow-up, 0-9 months), one comparative and five case series on custom BKA (follow-up, 0.25-72 months), and three case series on custom PFA (follow-up, 2-119 months). Three studies on custom UKA reported mean Knee Society Score (KSS) Knee of 86-94 and mean KSS Function of 94-95, and two studies on custom BKA reported mean KSS Knee of 90-94 and KSS function of 81, whereas one study on custom PFA reported KSS Knee of 91 and KSS Function of 89. Custom implants tended to have less bone-implant mismatch compared to off the shelf (OTS) implants. Revision rates were 3-25% for custom UKA (at 0-109 months), 3-5% for custom BKA (at 12-72 months), and 0-14% for custom PFA (at 2-119 months).

CONCLUSION

Due to the small number of comparative studies and lack of consistency in reported outcomes, it remains difficult to ascertain the benefits of custom partial knee arthroplasty. Anecdotal evidence suggests that, compared to OTS implants, custom implants result in less bone-implant mismatch and that 78-91% of patients are either satisfied or very satisfied after custom partial knee arthroplasty.

LEVEL OF EVIDENCE

IV.

Efficacy and safety of tranexamic acid in unicompartmental knee arthroplasty: A systematic review and meta-analysis

This meta-analysis aimed to assess whether administration tranexamic acid (TXA) could reduce blood loss and vascular events in patients undergoing unicompartmental knee arthroplasty (UKA). We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and case control trials (CCT) that compared outcomes of patients who did and did not receive TXA during UKA. We searched Cochrane Central Register of including PubMed, EMBASE, Web of Science, the Cochrane Library, Wan Fang data, CBM and CNKI for relevant studies. We assessed the risk of bias of the included studies and calculated pooled risk estimates. The primary outcome was operation time, intraoperative blood loss, postoperative HCT, postoperative HB, transfusion rate, dominant blood loss, postoperative drainage volume, hidden blood loss, total blood loss, postoperative ROM,postoperative VAS score, postoperative complications. Data were using fixed-effects or random-effects models with standard mean differences and risk ratios for continuous and dichotomous variables, respectively. Finally, 9 clinical studies with 744 patients were included in this meta-analysis. Compared with the control group, TXA group could reduced transfusion rate, dominant blood loss, postoperative drainage volume, hidden blood loss, and total blood loss, and increased postoperative HB with statistically significance. The main findings of this meta-analysis are that the transfusion rate, dominant blood loss, postoperative drainage volume, hidden blood loss, total blood loss and postoperative HB in the tranexamic acid group were superior to those in the routine group. Additional high-quality RCTs should be conducted in the future.

Arthroscopic-assisted robotic bi-unicompartmental knee arthroplasty: a pilot cadaveric study

INTRODUCTION

Although bicondylar arthroplasty showed great functional results, it encounters some difficulties to be performed routinely. On the other hand, arthroscopic techniques tend to replace open surgical techniques in sports medicine but strive to be developed in the field of arthroplasty. This study aimed to assess the feasibility of a micro-invasive bi-compartmental knee arthroplasty using both arthroscopic and robotic technologies (A-BiUKA).

MATERIALS AND METHODS

The study was conducted on complete fresh-frozen and embalmed cadaveric specimens. The main criterion of judgment was the successful positioning of trial implants through a minimal quad-sparing approach. Arthroscopy was used for bone-morphing and burring, supported by an image-free robotic system. Secondary criteria of judgment were axial deviation (measured using the navigation system), operating time, and incision length.

RESULTS

Ten A-BiUKA were performed. Implantation was successful in all cases. The mean preoperative frontal deviation was 179.8° ± 3.2 [175: 185], the mean postoperative frontal deviation was 178.5° ± 2.2 [175: 182], without any outliers. The mean correction was 1.7° ± 1.6 [0: 5]. Once the eight first A-UKA were performed, constituting the learning curve, the mean operative time for the remaining twelves surgeries was 90 min ± 6. The mean skin incision length was 3.35 cm ± 0.13 [3: 4].

CONCLUSION

Associated arthroscopic and robotic technologies allows to perform Bi-UKA procedure using a quad sparing mini-invasive approach. Clinical prospective studies have to confirm the feasibility and the clinical outcomes of this surgery.

Patellofemoral arthroplasty in combination with high tibial osteotomy can achieve good outcome for patients with medial-patellofemoral osteoarthritis

Background

The purpose of our study is to report on the clinical outcomes of patients who undergoing patellofemoral arthroplasty (PFA) in combination with a high tibial osteotomy (HTO). Due to this procedure's conservative and kinematics-preserving characteristics, we hypothesized that PFA in combination with HTO would result in good clinical outcomes in patients with medial and patellofemoral compartment osteoarthritis (MPFOA).

Methods

Patients who underwent PFA in combination with HTO for MPFOA from January 2018 to April 2020 were included in the study. Clinical outcomes were analyzed by comparing the Knee Society Score, Oxford Knee Score, Range of Motion, and Forgotten Joint Score before and after the procedure. Radiological evaluations were also performed to assess the tibiofemoral osteoarthritis progression and implant loosening. For all tests, the value of p < 0.05 was considered statistically significant.

Results

A total of nine consecutive patients who underwent PFA in combination with HTO were included. Two were males, seven were females. The average follow-up period was 2.6 ± 0.4 years. Clinical outcomes showed a significant improvement in the Knee Society Score (clinical score: 90.3 ± 8.5 and function score: 90.8 ± 7.8), Oxford Knee Score (43.6 ± 3.6), Forgotten Joint Score (71.2 ± 10.2), and knee Range of Motion (130.4 ± 8.1°) at the final follow-up. Additionally, hip-knee-ankle angle significantly decreased from -9.3 ± 2.1° preoperatively to 2.2 ± 1.2° at the final follow-up (p < 0.05). There were no complications for any patient during the follow-up time.

Conclusion

This study shows that patients who underwent PFA in combination with HTO for the treatment of MPFOA achieved good clinical and radiological outcomes. This combined surgery could be an effective alternative to treat MPFOA in well-selected patients.

No difference in sports participation and patient-reported functional outcomes between total knee arthroplasty and unicompartmental knee arthroplasty at minimum 2-year follow-up in a matched control study

PURPOSE

The purpose of this study was to compare (1) sports participation and type of sports activity between TKA and UKA patients; (2) functional outcome and activity level between TKA and UKA; and (3) survivorship of the prosthesis in both the groups.

METHODS

Prospectively collected data were obtained from an arthroplasty database to identify patients who underwent primary TKA and UKA. Both the cohorts of TKA and UKA were matched, controlling for age, sex, BMI and preoperative patient-reported outcomes, which include Oxford Knee Score (OKS), Tegner activity level, and visual analog scale (VAS) for pain score. After matching the two groups, 287 TKA and 69 UKA cases were available to be included in the study. Patients were evaluated pre- and postoperatively at 2 years for sports participation and sports preference, patient-reported outcomes, activity levels, and improvement in knee pain.

RESULTS

The mean age of the TKA and UKA groups were 75.7 ± 8.1 and 74.2 ± 8.8, respectively. There was no significant difference between the two groups concerning the demographic variables. Significant improvement was noted in the weekly sports participation at the final follow-up compared to preoperative sports participation in both the TKA and UKA groups (p < 0.05). All patients were able to return to their desired sporting activity. No significant difference was noted between the two groups in sports participation preoperatively and postoperatively (p > 0.05). OKS, Tegner activity level and VAS for pain demonstrated a significant improvement from preoperative to 2 years postoperatively (p < 0.05). However, preoperative and postoperative patient-reported outcomes did not differ significantly between the TKA and UKA groups (p > 0.05). No case of revision surgery was found at a 2-year follow-up in both groups.

CONCLUSION

Traditionally, in isolated medial compartment osteoarthritis, UKA has been considered to be the procedure with better functional outcomes, but the current study demonstrates that when confounding factors are controlled, both TKA and UKA are effective, and offer similar functional outcomes and result in similar improvement in sports participation. These findings will be helpful to counsel the patients to choose the best suitable operative procedure between UKA and TKA.

LEVEL OF EVIDENCE

Level 3.

Predictors of a forgotten joint after medial fixed-bearing unicompartmental knee arthroplasty

BACKGROUND

A forgotten joint is considered the ultimate goal of joint replacement. We aim to explore the predictive factors of a forgotten joint after fixed-bearing unicompartmental knee arthroplasty (UKA).

METHODS

This retrospective cohort study used prospectively collected data from 302 cases of medial-compartment UKA with a minimum of 2-year follow-up. The primary outcome was the achievement of a forgotten joint after UKA, according to the Forgotten Joint Score (FJS-12) at the last follow-up. Patients with FJS-12 > 84 were considered to have forgotten UKA. Univariate and multivariate logistic regression analyses were conducted with preoperative patient characteristics and surgery-related factors as potential predictors.

RESULTS

Of patients, 94 (31.1%) achieved a forgotten joint post-surgery. Multivariate logistic regression analysis revealed that preoperative hip-knee-ankle angle (HKAA), anatomic lateral distal femoral angle (aLDFA), and postoperative HKAA and HKAA changes were independent predictors of a forgotten joint. The probability of achieving a forgotten joint increased by 29% (OR = 1.29, 95% CI: 1.12-1.51) with a 1° increase in aLDFA. Preoperative HKAA, postoperative HKAA, HKAA changes (ΔHKAA), and outcomes exhibited a non-linear relationship. The probability of achieving a forgotten joint was the highest with preoperative HKAA > 172.0°, postoperative HKAA of 176.0-178.5°, and ΔHKAA < 5.5°.

CONCLUSION

To achieve the forgotten joint state, the ideal HKAA range after medial fixed-bearing UKA is 176.0-178.5° and ΔHKAA should be <5.5°. Patients with smaller preoperative aLDFA and HKAA have a lower probability of achieving a forgotten joint after UKA.

Satisfaction and Health-Related Quality of Life Following Hip and Knee Arthroplasty Surgeries in Indian Patients: A Cross-Sectional Study

INTRODUCTION

Recently, the patient-reported outcome measures (PROMs) have been considered as the most important assessment tool for surgical outcome evaluation in arthroplasty. However, no study from the Indian subcontinent has evaluated the PROM in the total hip (THA) and knee (TKA) arthroplasties.

MATERIALS AND METHODS

This cross-sectional study evaluated the health-related quality of life (HRQoL) of 1244 North Indian patients following primary THA and TKA who had at least one-year follow-up. This study included 617 patients with 664 THA and 627 patients with 1152 TKA. The patients were asked to answer the EQ-5D-5L questionnaires and EQ-VAS in their own languages. The EQ-5D-5L values were used to derive level frequency scores (LFS) with validated Indian norms of EuroQoL.

RESULTS

Ninety percent of THA and 82% of TKA patients rated excellent HRQoL using EQ-VAS. The regression analysis revealed age, gender, etiology and brand of prosthesis had a significant impact on EQ-5D-5L following THA. However, gender and simultaneous bilateral surgery were found to be important predictors of outcome in TKA. The mean value of LFS for THA was 0.95 ± 0.12 and TKA was 0.88 + 0.24 (p < 0.001). However, There was no difference in LFS between THA and TKA when only elderly patients (> 60 years) were considered (p = 0.168).

CONCLUSION

THA patients reported better HRQoL than TKA in the Indian subcontinent. One of the factors for a better outcome in hip arthroplasty was the relatively younger age of the patients. Patients above 60 years of age reported similar levels of statisfactior in both THA and TKA.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00589-x.

Improved joint awareness two years after total knee arthroplasty with a handheld image-free robotic system

Literature into the short-term follow-up of total knee arthroplasty (TKA) using a handheld image- free robotic system are scarce. The purpose of this study was to compare the clinical outcomes and patient-reported outcome measures (PROMs) between patients operated for TKA with an image- free robotic system (robot group) or conventionally TKA (conventional group) 2 years postoperatively. A total of 147 patients were evaluated after TKA, respectively 73 in the robot and 74 in conventional group. Outcome measures included adverse events (AEs), hospital readmission rate, patient satisfaction and the following PROMs: Pain Visual Analogue Score (VAS), Oxford Knee Score (OKS), Forgotten Joint Score Knee (FJS-12) and the EuroQOL-5D (EQ-5D). There were no statistically significant differences in the number of AEs; 8 (10.8%) in the conventional group versus 7 (9.7%) in the robot group. The FJS (p ≤ 0.05) and OKS (p ≤ 0.05) differed statistically in favour of the robot group. The EQ-5D and EQ-5D VAS did not statistically differed between the groups (p=0.231 and p=0.373 respectively). The VAS pain improved statically significant in both groups when comparing the pre- and postoperative values (5.8 points). Patients operated with a handheld image-free robotic system have the ability to forget their artificial knee joint in everyday life as measured with the FJS-12 at short-term follow-up.

Effectiveness of motor imagery for improving functional performance after total knee arthroplasty: a systematic review with meta-analysis

Background

The aim of this study was to appraise the effects of motor imagery on the functional performance improvement among total knee arthroplasty patients systematically. We hypothesized a relatively greater recovery in the motor imagery group.

Methods

Medline (Ovid), Embase and Cochrane Controlled Register of Trials (CENTRAL) were searched from inception to October 1st, 2021. We included randomized controlled trials evaluating the effects of motor imagery on the functional recovery among total knee arthroplasty patients. Measurements included range of motion, strength intensity, Visual Analogue Scale, Time Up and Go Test, Oxford Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index, all of which were evaluated before and after intervention. Mean differences (MD) or standard mean differences (SMD) and 95% confidence intervals (CI) were calculated. The Cochrane risk of bias tool was used to assess the risk of bias.

Results

Six studies with 168 patients were included for the meta-analysis. The SMD of strength intensity was increased (SMD = 0.90, 95% CI = [0.47]–[1.32], P < 0.001). The SMD of Visual Analogue Scale was reduced (SMD =  − 0.91; 95% CI = [− 1.29]–[− 0.52], P < 0.001). The SMD of Time Up and Go Test was reduced (SMD =  − 0.56, 95% CI = [− 0.94]–[− 0.19], P = 0.003). The MD of Oxford Knee Score was slightly increased (MD = 0.79-point, 95% CI = [− 0.31]–[1.88], P = 0.159). The outcomes of range of motion, Western Ontario and McMaster Universities Osteoarthritis Index were described according to the original data.

Conclusion

Compared with control therapy, motor imagery in the intervention group achieved an effective treatment for strength enhancement, pain reduction and physical activities improvement. More large-scale, prospective researches are needed in the future.

Trial registration: The PROSPERO trial registration number is CRD42021250996.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-02946-4.

Joint awareness after unicompartmental knee arthroplasty and total knee arthroplasty: a systematic review and meta-analysis of cohort studies

PURPOSE

The purpose of this systematic review and meta-analysis is to evaluate the joint awareness after unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). It was hypothesized that patients with UKA could better forget about their artificial joint in comparison to TKA.

METHODS

A search of major literature databases and bibliographic details revealed 105 studies evaluating forgotten joint score in UKA and TKA. Seven studies found eligible for this review were assessed for risk of bias and quality of evidence using the Newcastle-Ottawa Scale. The forgotten joint score (FJS-12) was assessed at 6 months, 1 year, and 2 years.

RESULTS

The mean FJS-12 at 2 years was 82.35 in the UKA group and 74.05 in the TKA group. Forest plot analysis of five studies (n = 930 patients) revealed a mean difference of 7.65 (95% CI: 3.72, 11.57, p = 0.0001; I² = 89% with p < 0.0001) in FJS-12 at 2 years. Further sensitivity analysis lowered I² heterogeneity to 31% after exclusion of the study by Blevin et al. (MD 5.88, 95%CI: 3.10, 8.66, p < 0.0001). A similar trend of differences in FJS-12 between the groups was observed at 6 months (MD 32.49, 95% CI: 17.55, 47.43, p < 0.0001) and at 1 year (MD 25.62, 95% CI: 4.26, 46.98, p = 0.02).

CONCLUSIONS

UKA patients can better forget about their artificial joint compared to TKA patients.

LEVEL OF EVIDENCE

III.

The Renaissance of Unicompartmental Knee Arthroplasty appears rational - A radiograph-based comparative Study on adverse Events and patient-reported Outcomes in 353 TKAs and 98 UKAs

PURPOSE

Total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) are both considered suitable for antero-medial osteoarthritis and spontaneous osteonecrosis of the knee. National registry data are consistent in showing higher revision rates for UKA. Adequately adjusted, these findings may be challenged by differences in adverse events and patient-reported outcomes, as both can have serious long-term implications. Based on preoperative radiographs, the aim was to retrospectively compare the two principle surgeries in these respects.

METHODS

All TKA procedures in 2016 in one Swedish county council were, according to certain radiograph-based consensus criteria, visually evaluated for medial UKA suitability. Then, using different regression models, they were compared with the corresponding medial UKAs performed in 2015-2017 regarding complications and patient-reported outcomes one year after surgery.

RESULTS

The UKA group showed an 82% reduced risk (OR 0.2; 95% CI 0.0-0.6) of any complications, whereas the 55% reduced risk of severe complication did not reach statistical significance (OR 0.5; 95% CI 0.1-2.1). These findings corresponded in high-volume surgeries to an absolute complication rate of 0% in the UKA group and 10% in the TKA group (p = 0.005) and to a severe complication rate of 0% and 5% respectively (p = 0.05). Though no differences were seen in any general patient-reported outcomes, the pain and function based OMERACT-OARSI responder criteria indicated in both around a 60% better chance of any response (OR 1.6 CI % 0.6-4.5) and a high response (OR 1.6; 95% CI 0.7-3.4) in the UKA group.

CONCLUSION

No differences were shown in patient-reported outcomes but a clear difference in risk of complications, favoring the UKA procedure.