Risk factors for manipulation under anaesthesia after total knee arthroplasty

Revolutionizing healthcare: a comparative insight into deep learning's role in medical imaging

Recently, Deep Learning (DL) models have shown promising accuracy in analysis of medical images. Alzeheimer Disease (AD), a prevalent form of dementia, uses Magnetic Resonance Imaging (MRI) scans, which is then analysed via DL models. To address the model computational constraints, Cloud Computing (CC) is integrated to operate with the DL models. Recent articles on DL-based MRI have not discussed datasets specific to different diseases, which makes it difficult to build the specific DL model. Thus, the article systematically explores a tutorial approach, where we first discuss a classification taxonomy of medical imaging datasets. Next, we present a case-study on AD MRI classification using the DL methods. We analyse three distinct models-Convolutional Neural Networks (CNN), Visual Geometry Group 16 (VGG-16), and an ensemble approach-for classification and predictive outcomes. In addition, we designed a novel framework that offers insight into how various layers interact with the dataset. Our architecture comprises an input layer, a cloud-based layer responsible for preprocessing and model execution, and a diagnostic layer that issues alerts after successful classification and prediction. According to our simulations, CNN outperformed other models with a test accuracy of 99.285%, followed by VGG-16 with 85.113%, while the ensemble model lagged with a disappointing test accuracy of 79.192%. Our cloud Computing framework serves as an efficient mechanism for medical image processing while safeguarding patient confidentiality and data privacy.

The association between losartan potassium prescription and postoperative outcomes following total knee arthroplasty: A TriNetX analysis

BACKGROUND

Total knee arthroplasty (TKA) is a common surgical procedure performed to alleviate pain and improve functional outcomes in patients with knee osteoarthritis and rheumatoid arthritis who have failed conservative treatments. Arthrofibrosis has been extensively studied due to its negative impact on TKA outcomes. Losartan, an angiotensin receptor blocker (ARB), has the potential to improve TKA outcomes by inhibiting TGF-β and decreasing fibrosis. This study aims to analyze a large-scale, real-world healthcare database to investigate the association between losartan potassium prescription and postoperative outcomes such as readmissions, ED visits, and the need for MUA or revision TKA.

HYPOTHESIS

Based on previous literature and the nature of ARBs, it is expected that the addition of losartan will aid in better outcomes for patients following a primary TKA.

PATIENTS AND METHODS

In this retrospective observational study, the TriNetX Research Network (TriNetX) database was queried as of June 21, 2023. All patients who underwent a primary total knee arthroplasty (TKA) prior to June 21, 2022 were included. Patients were then divided into two cohorts by whether they had an active losartan potassium prescription within the year prior to their surgery to within 90days postoperatively. Patients were then propensity-matched to eliminate differences in demographics and comorbidities.

RESULTS

Losartan TKA patients were 1.18 [OR: 0.85 (95% CI: 0.79-0.90), p<0.001] times less likely to be readmitted within 90days and were 1.15 (OR: 0.87 (95% CI: 0.79-0.96); p=0.009) times less likely to undergo a manipulation under anesthesia (MUA) within the 1-year postoperative period. There were no statistically significant differences in rates of emergency department (ED) visits at 90days postoperatively or revision TKAs at 1year postoperatively.

DISCUSSION

In conclusion, patients with an active losartan prescription prior to TKA had a significantly lower likelihood of readmission within 90days and a lower likelihood of undergoing MUA within the 1-year postoperative period compared to patients not taking losartan. This presents an opportunity for further clinical investigation to explore the value of losartan in TKA.

LEVEL OF EVIDENCE

III; an observational cohort study.

Nearly 14-Fold Increased Risk of Manipulation Under Anesthesia After Total Knee Arthroplasty When Previous Contralateral Total Knee Arthroplasty Required Manipulation Under Anesthesia

BACKGROUND

Stiffness remains a common complication after primary total knee arthroplasty (TKA). Manipulation under anesthesia (MUA) is the gold standard treatment for early postoperative stiffness; however, there remains a paucity of data on the risk of MUA after primary TKA if a prior contralateral TKA required MUA.

METHODS

We performed a retrospective review of 3,102 patients who had staged primary TKAs between 2016 and 2021. The mean body mass index was 33 (range, 18 to 59) and the mean age was 67 years (range, 24 to 91). The mean preoperative range of motion for the first TKA was 2 to 104°, and for the contralateral TKA was 1 to 107°. The primary outcomes were MUA following first and second primary TKAs. Multivariable Poisson regressions were used to evaluate associations between risk factors and outcomes.

RESULTS

The rate of MUA after the first TKA was 2.6% (n = 83 of 3,102) and 1.3% (n = 40 of 3,102) after the contralateral TKA. After adjustment, there was a nearly 14-fold higher rate of MUA after the second TKA if the patient had an MUA after the first TKA (relative risk, 13.80; 95% CI [confidence interval], 7.14 to 26.66). For the first TKA, increasing age (adjusted risk ratio [ARR], 0.65; 95% CI, 0.50 to 0.83) and increasing body mass index (ARR, 0.65; 95% CI, 0.47 to 0.90) were associated with lower risk for MUA. For the second TKA, increasing age was associated with a lower risk of MUA (ARR, 0.60; 95% CI, 0.45 to 0.80).

CONCLUSIONS

For patients undergoing staged bilateral TKA, patients who undergo MUA following the first primary TKA are nearly 14-fold more likely to undergo an MUA following the contralateral primary TKA than those who did not have an MUA after their first TKA.

Range-of-Motion Predictors for Repeat Manipulation Under Anesthesia and Revision Surgery for Stiffness After Total Knee Arthroplasty

Introduction

Manipulation under anesthesia (MUA) is a first-line treatment for stiffness after total knee arthroplasty (TKA), but predicting outcomes after MUA can be difficult.

Purpose

We sought to determine the association between pre-MUA range-of-motion (ROM) and the risk of repeat MUA and revision in patients who underwent primary TKA.

Methods

We conducted a retrospective review of 543 MUAs for stiffness at a single institution. Mean age was 62.5 years, and 64% were female. Second MUA or revision TKA were considered failures of treatment. Penalized logistic regression models were used to assess risk factors for failures. The Kaplan-Meier survivorship was used to examine survivorship free from second MUA or revision.

Results

Before and after MUA, there was significant improvement in knee flexion (78.0° vs 112.8°, respectively) and extension (4.1° vs 0.8°, respectively); 6.4% of patients required repeat MUA and 5.3% required revision TKA. Survivorship free of second MUA was 90.9%, revision for stiffness was 92.4%, and all-cause revision was 88.2% at 2 years post-MUA. Patients with pre-MUA flexion contracture of ≥5° were more likely to undergo second MUA revision for stiffness and any revision. There were significant improvements in patient-reported outcomes postoperatively.

Conclusions

This retrospective chart review suggests that MUA is an effective treatment for post-TKA stiffness, with good early survivorship, and that worse pre-MUA ROM is associated with MUA failure and need for repeat MUA or revision. This information may have implications for patient counseling and management.

Complications of Bicruciate-Retaining Total Knee Arthroplasty: The Importance of Alignment and Balance

Bicruciate-retaining total knee arthroplasty (BCR TKA) results in kinematics closer to the native knee and in greater patient satisfaction but information concerning its outcome and complications is lacking.The goal of this study is to report the clinical and radiological outcomes of BCR prosthesis implanted using a spacer-based gap balancing technique and to assess if some preoperative factors are associated with a worse prognosis.A cohort of 207 knees in 194 patients who underwent BCR TKA, with a minimum 1-year follow-up, was retrospectively analyzed.Patients were followed at 6 weeks, 6 months, 1 year, and then every following year postoperatively, and filled questionnaires (Knee Society and Knee injury and Osteoarthritis Outcome Score) at every visit. Clinical and radiological assessments included range of motion, knee alignment, pain, and complications as defined by the Knee Society's Standardized list and definition of Complication of Total Knee Arthroplasty.Forty-three knees (20.8%) suffered major complications. Twenty-one knees (10.1%) underwent revision at an average of 32.1 months after the index procedure. Revision-free survival at 100 months was 85.7%. Revision was performed for aseptic tibial loosening in eight knees (3.9%) and stiffness in five knees (2.4%). There were 29 reoperations other than revision (14.0%), the most frequent procedure being manipulation under anesthesia in 14 knees (6.8%). Minor complications included tendonitis (20.8%), persistent synovitis (6.8%), and superficial wound infections (6.3%).All outcomes scores were greatly improved at the 1-year follow-up compared with preoperatively (p < 0.001). However, maximum flexion at the last follow-up was significantly reduced compared with preoperatively (mean maximum flexion ± standard deviation: 119.9 ± 15.6 vs. 129.9 ± 14.4, p < 0.001). Aseptic tibial loosening was associated with a hypercorrection in varus of preoperative valgus knees (p = 0.012).BCR TKA can give functional results similar to other types of prostheses but involves a substantial risk of complications. Important factors that can explain failed BCR TKA and guide its use were identified, more particularly knee alignment and its role in aseptic tibial loosening.

Cemented total knee arthroplasty provides greater knee range of motion at 2 years than cementless technique

INTRODUCTION

Optimal fixation method between cemented, cementless, and hybrid techniques for total knee arthroplasty (TKA) is still debated. The purpose of this study is to evaluate the clinical outcomes of patients undergoing cemented versus cementless TKA.

METHODS

We reviewed 168 patients who underwent a primary TKA at a single academic institution between January 2015 and June 2017. Patients were categorized into cemented (n = 80) or cementless (n = 88) groups. Only patients with greater than or equal to 2-year follow-up were included in the study. Multivariate regressions were performed to analyze the relationship between the surgical fixation technique and the clinical outcomes.

RESULTS

There were no differences in demographics or baseline operative characteristics between the two groups. The cemented group had fewer manipulations under anesthesia (MUA) (4 vs. 15, p = 0.01), longer intraoperative tourniquet times (101.30 vs. 93.55 min, p = 0.02), and increased knee range of motion (ROM) at final follow-up (111.48 vs. 103.75°, p = 0.02) compared to the cementless group.

DISCUSSION AND CONCLUSION

Both cemented and cementless component fixation are viable options for (TKA). This study found that patients who underwent a cemented TKA required fewer MUA's and had greater final ROM compared to patients undergoing cementless TKA. Additional research is required regarding cementless and cemented fixation. We believe that the choice of which fixation technique to use ultimately comes down to patient characteristics and surgeon preference.

Role of non-ASA VTE prophylaxis in risk for manipulation following primary total knee arthroplasty

INTRODUCTION

Stiffness and decreased range of motion frequently lead to hindrance of activities of daily living and dissatisfaction follow total knee arthroplasty (TKA). This study aims to evaluate the effect of non-aspirin (ASA) chemoprophylaxis and determine patient-related risk factors for stiffness and need for manipulation under anesthesia (MUA) following primary TKA.

MATERIALS AND METHODS

A review of all patients undergoing primary TKA from 2013 to 2019 at a single academic orthopedic hospital was conducted. The primary outcome measure was MUA performed post-operatively. Chi-square analysis and Mann-Whitney U test were used to determine statistically significant relationships between risk factors and outcomes. Significance was set at p < 0.05. Univariate logistic regression was performed to control for identified independent risk factors for MUA.

RESULTS

A total of 11,550 patients undergoing primary TKA from January 2013 to September 2019 at an academic medical center were included in the study. Increasing age and Charlson Comorbidity Index were associated with statistically significant decreased odds of MUA (0.93, 95% CI: 0.92-0.94, p < 0.001, OR 0.71, 95% CI 0.63-0.79, p < 0.001). Active smokers had a 2.01 increased odds of MUA (OR 2.01, 95% CI 1.28, 3.02, p < 0.001). There was no significant difference in rates of MUA between ASA and non-ASA VTE prophylaxis (p 0.108).

CONCLUSIONS

Younger age, lower CCI, and history of smoking are associated with a higher rate, while different chemical VTE prophylaxis does not influence rate of MUA after TKA. Arthroplasty surgeons should consider these risk factors when counseling patient preoperatively. Understanding each patients' risk for MUA allows surgeons to appropriately set preoperative expectations and reasonable outcome goals.

Manipulation Following Primary Total Knee Arthroplasty is Associated With Increased Rates of Infection and Revision

BACKGROUND

Stiffness following total knee arthroplasty (TKA) is a disabling complication and manipulation under anesthesia (MUA) is often performed as an early intervention. Few studies have focused on the revision risk, infection risk, demographics, and clinical outcomes in Medicare patients undergoing MUA following primary TKA.

METHODS

We reviewed 142,440 patients who had primary TKA from a national database and identified 3,652 patients (2.6%) who underwent MUA. Patient demographics and comorbid conditions were evaluated to identify risk factors. Incidence of revision and periprosthetic joint infection (PJI) at 1-, 2-, and 5-year time points in a cohort of MUA patients was compared to patients who did not undergo MUA. Multivariate Cox regressions were used for statistical analyses.

RESULTS

The incidence of MUA was higher in Black versus White individuals (4.1 versus 2.5%, P < .001). Revision risk was significantly greater in the MUA group at 1-, 2-, and 5-year time points with a hazard ratio (HR) of, 3.81, 3.90, and 3.22 respectively, P < .001. One- and 2-year revision risk was significantly greater when MUA occurred at 6 to 12 months post-TKA when compared to <3 months, P < .05. Risk of PJI was significantly greater in the MUA group with a HR of 2.2, 2.2, and 2.1 at 1, 2, and 5 years, respectively P < .001.

CONCLUSION

The incidence of MUA was 2.6%. There was an increased incidence of revision surgery and PJI in patients undergoing MUA. Patients at increased risk for stiffness following TKA should be closely monitored and treated with early intervention to minimize risk of poor outcomes.

Manipulation Under Anesthesia is Safe After Cementless Total Knee Arthroplasty: A Multicenter Study

BACKGROUND

Cementless total knee arthroplasty (TKA) is thought to facilitate durable, biological fixation between the bone and implant. However, the 4-12 weeks required for osseointegration coincides with the optimal timeframe to perform a manipulation under anesthesia (MUA) if a patient develops postoperative stiffness. This study aims to determine the impact of early MUA on cementless fixation by comparing functional outcomes and survivorship of cementless and cemented TKAs.

METHODS

A consecutive series of patients who underwent MUA for postoperative stiffness within 90 days of primary, unilateral TKA at 2 academic institutions between 2014 and 2018 were identified. Cases involving extensive hardware removal were excluded. Cementless TKAs undergoing MUA (n = 100) were propensity matched 1:1 to cemented TKAs undergoing MUA (n = 100) using age, gender, body mass index, and year of surgery. Both groups had comparable baseline Knee Injury and Osteoarthritis Outcome Scores (KOOS), Short Form (SF)-12 Physical, and SF-12 Mental scores. MUA-related complications as well as postoperative KOOS and SF-12 scores were compared.

RESULTS

MUA-related complications were equivalently low in both groups (P = .324), with only 1 patella component dissociation in the cementless group. No tibial or femoral components acutely loosened in the perioperative period. Postoperative KOOS (P = .101) and SF-12 Mental scores (P = .380) were similar between groups. Six-year survivorship free from any revision after MUA was 98.0% in both groups (P = 1.000).

CONCLUSION

Early postoperative MUA after cementless TKA was not associated with increased MUA-related complications or worse patient-reported outcomes compared to cemented TKA. Short-term survivorship was also comparable, suggesting high durability of the bone-implant interface.

Factors affecting range of motion following two-stage revision arthroplasty for chronic periprosthetic knee infection

Introduction

The purpose of this study was to evaluate factors that affect range of motion (ROM) following two-stage revision arthroplasty as a treatment for chronic periprosthetic knee infection.

Materials and methods

A total of 98 patients diagnosed with chronic periprosthetic joint infection (PJI) following primary total knee arthroplasty between January 2009 and December 2019 and then underwent two-stage revision arthroplasty were reviewed retrospectively. Multiple regression analysis was performed to evaluate the factors that affect ROM after two-stage revision arthroplasty. ROM after two-stage revision arthroplasty was used as a dependent variable, while age at the time of surgery, ROM at PJI diagnosis, ROM after the first-stage surgery, the interval between the first-stage surgery and the second-stage surgery, whether a re-operation was performed before the second-stage surgery, culture results (culture negative or culture positive), and body mass index (BMI) were used as independent variables.

Results

Multiple regression analysis (R2 = 0.843) revealed that among the independent variables, ROM (β = 0.604, P < 0.001) after the first-stage surgery, whether a re-operation was performed before the second-stage surgery (β =  − 8.847, P < 0.001), the interval between the first-stage surgery and the second-stage surgery (β = − 0.778, P = 0.003), and BMI (β =  − 0.698, P = 0.041) were associated with ROM after two-stage revision arthroplasty, the dependent variable.

Conclusions

In two-stage revision arthroplasty for chronic periprosthetic knee infection, ROM after the first-stage surgery, whether a re-operation was performed before the second-stage surgery, the interval between the first-stage surgery and the second-stage surgery, and BMI were found to be factors that were associated with ROM after two-stage revision arthroplasty.

Understanding rates, risk factors, and complications associated with manipulation under anesthesia after total knee arthroplasty (TKA): An analysis of 100,613 TKAs

BACKGROUND

Considering the growing adoption of technology-assisted total knee arthroplasties (TKA), previous database studies evaluating post-operative stiffness may be outdated. The present study aimed to: (1) evaluate the incidence of manipulation under anesthesia (MUA) after primary TKA; (2) determine independent risk factors for MUA; and (3) assess complications after MUA.

METHODS

Primary TKAs, with at least 6-month follow-up, were identified from the Florida State Inpatient Database (January 2016-June 2018) and linked to outpatient records from the Florida State Ambulatory Surgery and Services Database. Multivariable regression analyses were performed to compare patient factors and complications (e.g., mechanical, non-mechanical, infectious) associated with MUA, while adjusting for baseline demographics, comorbidities, use of robotic- and computer-technologies, time to MUA (0-3, 3-12, or >12 months), and need for repeat MUA (one-time vs >1).

RESULTS

The MUA rate was 2.8% (2821 of 100,613). Being younger, a woman, Black or Hispanic; having private or self-pay insurance; and conventional TKA were associated with significantly higher odds of undergoing MUA. Higher rates of mechanical complications and acute posthemorrhagic anemia were observed in the MUA cohort. Time to MUA, repeat MUA, and baseline demographics were not associated with complication rates among the MUA cohort.

CONCLUSION

Overall, 1 in 36 patients underwent MUA after primary TKA. Several non-modifiable patient characteristics, such as Black or Hispanic race, female sex, and younger age were associated with an increased risk of MUA. However, technology-assisted TKA might help to decrease the risk of MUA.

Racial Differences in Manipulation Under Anesthesia Rates Following Total Knee Arthroplasty

BACKGROUND

Despite the extensive literature on racial disparities in care and outcomes after total knee arthroplasty (TKA), data on manipulation under anesthesia (MUA) is lacking. We aimed to determine (1) the relationship between race and rate of (and time to) MUA after TKA, and (2) annual trends in racial differences in MUA from 2013 to 2018.

METHODS

This retrospective cohort study (using 2013-2018 Medicare Limited Data Set claims data) included 836,054 primary TKA patients. The primary outcome was MUA <1 year after TKA; time from TKA to MUA in days was also recorded. A mixed-effects multivariable model measured the association between race (White, Black, Other) and odds of MUA. Odds ratios (OR) and 95% confidence intervals (CI) were reported. A Cochran Armitage Trend test was conducted to assess MUA trends over time, stratified by race.

RESULTS

MUA after TKA occurred in 1.7%, 3.2% and 2.1% of White, Black, and Other race categories, respectively (SMD = 0.07). After adjustment for covariates, (Black vs White) patients had increased odds of requiring an MUA after TKA: odds ratio (OR) 1.97, 95% confidence intervals (CI) 1.86-2.10, P < .0001. Moreover, White (compared to Black) patients had significantly shorter time to MUA after TKA: 60 days (interquartile range [IQR] 46-88) versus 64 days (interquartile range [IQR] 47-96); P < .0001. These disparities persisted from 2013 through 2018.

CONCLUSION

Continued racial differences exist for rates and timing of MUA following TKA signifying the continued need for efforts aimed toward understanding and eliminating inequalities that exist in total joint arthroplasty (TJA) care.

Aspirin Administered for Venous Thromboembolism Prophylaxis May Protect Against Stiffness Following Total Knee Arthroplasty

BACKGROUND

Aspirin has become the main agent for venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA). This study assessed whether aspirin is associated with less knee stiffness compared to warfarin and other chemoprophylaxis agents.

METHODS

This is a retrospective review of all primary and revision TKAs performed between January 2009 and October 2020 at a high volume institution. Demographics, comorbidity data, and operative variables were extracted from medical records. VTE prophylaxis administered during this time period included aspirin, warfarin, and "others" (factor Xa, unfractionated heparin, low-molecular-weight heparin, fondaparinux, adenosine diphosphate receptor inhibitor, and direct thrombin inhibitor). The primary outcome assessed was manipulation under anesthesia (MUA) performed within 6 months of index surgery. Secondary outcome included major bleeding events. Univariate followed by multivariate regression analyses were performed.

RESULTS

A total of 15,903 cases were included in the study, of which 531 (3.3%) patients developed stiffness that required MUA. The rates of MUA were 2.7% (251/9223) for patients receiving aspirin, 4.2% (238/5709) for patients receiving warfarin, and 4.3% (42/971) for all others (P's < .001). Multivariate regression analysis confirmed that aspirin is associated with lower rates of VTE compared to warfarin (adjusted odds ratio 1.423, 95% confidence interval 1.158-1.747, P < .001) and compared to other anticoagulation medications (adjusted odds ratio 1.742, 95% confidence interval 1.122-2.704, P = .013). Major bleeding events were also significantly lower in patients who received aspirin compared to the other 2 groups (P's = .001).

CONCLUSION

Aspirin prophylaxis is associated with lower rates of MUA following TKA compared to warfarin and other VTE chemoprophylactic agents when grouped together.

Excellent and Good Results Treating Stiffness with Early and Late Manipulation after Unrestricted Caliper-Verified Kinematically Aligned TKA

Manipulation under anesthesia (MUA) for stiffness within 6 to 12 weeks after mechanically aligned total knee arthroplasty (TKA) generally yields better outcome scores than an MUA performed later. However, the timing of MUA after unrestricted, caliper-verified, kinematically aligned (KA) TKA remains uncertain. A retrospective review identified 82 of 3558 (2.3%) KA TKA patients treated with an MUA between 2010 and 2017. Thirty patients treated with an MUA within 3 months of the TKA (i.e., early) and 24 in the late group (i.e., >3 months) returned a questionnaire after a mean of 6 years and 5 years, respectively. Mean outcome scores for the early vs. late group were 78 vs. 62 for the Forgotten Joint Score (FJS) (p = 0.023) and 42 vs. 39 for the Oxford Knee Score (OKS) (p = 0.037). Subjectively, the early vs. late group responses indicated that 83% vs. 67% walked without a limp, 73% vs. 54% had normal extension, and 43% vs. 25% had normal flexion. An MUA within 3 months after unrestricted KA TKA provided excellent FJS and OKS at final follow-up relative to a late MUA. A late MUA performed after 3 months is worth consideration because of the good FJS and OKS scores, albeit with a risk of a persistent limp and limitation in knee extension and flexion.

Impact of intra-operative predictive ligament balance on post-operative balance and patient outcome in TKA: a prospective multicenter study

INTRODUCTION

New technologies exist which may assist surgeons to better predict final intra-operative joint balance. Our objectives were to compare the impact of (1) a predictive digital joint tensioning tool on intra-operative joint balance; and (2) joint balance and flexion joint laxity on patient-reported outcomes.

MATERIALS AND METHODS

Two-hundred Eighty patients received posterior cruciate ligament sacrificing TKA with ultra-congruent tibial inserts using a robotic-assisted navigation platform. Patients were divided into those in which a Predictive Plan with a digital joint-tensioning device was used (PP) and those in which it was not (NPP), in all cases final post-operative joint gaps were collected immediately before final implantation. Demographics and KOOS were collected pre-operatively. KOOS, complications and satisfaction were collected at 3, 6 and 12 months post-operatively. Optimal balance difference between PP and NPP was defined and compared using area-under-the-curve analysis (AUC). Outcomes were then compared according to the results from the AUC.

RESULTS

AUC analysis yielded a balance threshold of 1.5 mm, in which the PP group achieved a higher rate of balance throughout flexion compared to the NPP group: extension: 83 vs 52%; Midflexion: 82 vs 55%; Flexion 89 vs 68%; Flexion to Extension 80 vs 49%; p ≤ 0.003. Higher KOOS scores were observed in knees balanced within 1.5 mm across all sub-scores at various time points, however, differences did not exceed the minimum clinically important difference (MCID). Patients with > 1.5 mm flexion laxity medially or laterally had an increased likelihood of 2.2 (1.1-4.4) and 2.5 (1.3-4.8), respectively, for failing to achieve the Patient Acceptable Symptom State for KOOS Pain at 12 months. Patient satisfaction was high in both the PP and NPP groups (97.4 and 94.7%, respectively).

CONCLUSIONS

Use of a predictive joint tensioning tool improved the final balance in TKA. Improved outcomes were found in balanced knees; however, this improvement did not achieve the MCID, suggesting further studies may be required to define optimal balance targets. Limiting medial and lateral flexion laxity resulted in an increased likelihood of achieving the Patient Acceptable Symptom State for KOOS Pain.

Manipulation under anaesthesia after primary total knee arthroplasty : minimal differences in intravenous sedation alone versus neuraxial anaesthesia

AIMS

Manipulation under anaesthesia (MUA) remains an effective intervention to address restricted range of motion (ROM) after total knee arthroplasty (TKA) and occurs in 2% to 3% of primary TKAs at our institution. Since there are few data on the outcomes of MUA with different anaesthetic methods, we sought to compare the outcomes of patients undergoing MUA with intravenous (IV) sedation and neuraxial anaesthesia.

METHODS

We identified 548 MUAs after primary TKA (136 IV sedation, 412 neuraxial anaesthesia plus IV sedation) from March 2016 to July 2019. The mean age of this cohort was 62 years (35 to 88) with a mean body mass index of 31 kg/m² (18 to 49). The mean time from primary TKA to MUA was 10.2 weeks (6.2 to 24.3). Pre-MUA ROM was similar between groups; overall mean pre-MUA extension was 4.2° (p = 0.452) and mean pre-MUA flexion was 77° (p = 0.372). We compared orthopaedic complications, visual analogue scale (VAS) pain scores, length of stay (LOS), and immediate and three-month follow-up knee ROM between these groups.

RESULTS

Following MUA, patients with IV sedation had higher mean VAS pain scores of 5.2 (SD 1.8) compared to 4.1 (SD = 1.5) in the neuraxial group (p < 0.001). The mean LOS was shorter in patients that received IV sedation (9.5 hours (4 to 31)) compared to neuraxial anaesthesia (11.9 hours (4 to 51)) (p = 0.009), but an unexpected overnight stay was similar in each group (8.6%). Immediate-post MUA ROM was 1° to 121° in the IV sedation group and 0.9° to 123° in the neuraxial group (p = 0.313). Three-month follow-up ROM was 2° to 108° in the IV sedation group and 1.9° to 110° in the neuraxial anaesthesia group (p = 0.325) with a mean loss of 13° (ranging from 5° gain to 60° loss), in both groups by three months. No patients in either group sustained a complication.

CONCLUSION

IV sedation alone and neuraxial anaesthesia are both effective anaesthetic methods for MUA after primary TKA. Surgeons and anaesthetists should offer these anaesthetic techniques to match patient-specific needs as the orthopaedic outcomes are similar. Also, patients should be counselled that ROM following MUA may decrease over time. Cite this article: Bone Joint J 2021;103-B(6 Supple A):126-130.

Patients undergoing manipulation after total knee arthroplasty are at higher risk of revision within 2 years

BACKGROUND

Total knee arthroplasty (TKA) is a very common orthopedic procedure and stiffness is a common complication following TKA. There is extensive data regarding timing and success of Manipulation under anesthesia (MUA) for stiffness following TKA. However, Studies reporting outcome following MUA have often focused on the improvement in ROM and improvement in functional score with very few studies reporting on the revision risk.

METHODS AND MATERIALS

In this study we retrospectively reviewed PearlDiver insurance database and analyzed the characteristics of the patient undergoing MUA after TKA. We also analyzed the risk of revision at 2 years in a cohort of MUA patients who were matched to patients without MUA.

RESULT

Our study identified 9156 patients who underwent MUA within one year following TKA. MUA was slightly more common in females and risk of manipulation decreases with increasing age. Comparative analysis showed that at two years, patients in the matched MUA cohort (538 patients, 5.99%) were 2.9 times more likely to undergo revision TKA compared to the matched non MUA group (194, 2.16%)OR 2.88 (95% CI-2.44 to 3.41), P < 0.05 CONCLUSION: Retrospective database review showed that the risk of revision is higher in patients undergoing MUA after TKA and hence patient should be counselled about the possibility of revision in the future.

A matched cohort study between cementless TKA and cemented TKA shows a reduction in tourniquet time and manipulation rate

Introduction

Cementless total knee arthroplasty (TKA) is now becoming more acceptable with the advent of newer ongrowth constructs and better initial fixation. It has been proposed that cementless TKA may save OR time and result in a lower incidence of manipulation. This study was designed to assess the difference between cemented and cementless TKA.

Methods

Our hospital statistician performed a matched cohort analysis between 127 cementless TKAs and 127 cemented TKRs performed by a single surgeon. Patients were matched on age and BMI. Mean tourniquet time between the cemented and cementless TKAs was assessed as well as the rate of manipulation between these groups. Of note, a tourniquet was routinely used in both the cementless and cemented cohorts to reduce confounding bias.

Results

A total of 127 cementless TKAs with a mean age of 60.8 years and mean BMI 32.2 were compared to 127 cemented TKAs with a mean age of 61.5 years and mean BMI of 32.2 at an average follow-up of 2.0 years. There was a statistically significant reduction in tourniquet time in the cementless TKA cohort at 45.7 min compared to the cemented TKA cohort at 54.8 min (p = 0.001). Estimated blood loss was similar in both the cementless (179.5 ml) and cemented (196 ml) cohorts (p = 0.3) and postoperative outcomes, including UCLA score.In addition, the cementless TKA cohort had a manipulation rate of 0% compared to 3.1% for the cemented TKA group (p = 0.044).

Discussion and conclusion

While cementless and cemented TKA have shown similar PROMs and survivorship, we demonstrated a significant reduction in tourniquet time with cementless TKRs, with similar estimated blood loss, and a lower incidence of manipulation with cementless TKRs in this matched cohort study. The increased cost of a cementless implant may be negated if one considers the cost savings of not using cement, the cost savings of not performing manipulations, and the shorter operative time.