Increased symptoms of stiffness 1 year after total knee arthroplasty are associated with a worse functional outcome and lower rate of patient satisfaction

Patients Undergoing Manipulation under Anesthesia following Primary Total Knee Arthroplasty: Are Their Patient-Reported Outcome Measures Inferior?

Stiffness after total knee arthroplasty (TKA) can lead to decreased function and patient dissatisfaction. Manipulation under anesthesia (MUA) is often performed to improve range of motion (ROM); however, there is no consensus on indications or timing. The purpose of this study was to compare clinical results and patient-reported outcome measures (PROMs) between patients who underwent MUA versus those with an uncomplicated postoperative course following primary TKA. This was an institutional review board-approved retrospective review of 116 consecutive patients who underwent MUA from 2013 to 2019 following primary TKA due to stiffness. Indication for MUA was failure to achieve 105 degrees of knee flexion at 6 weeks following surgery. Five patients underwent revision surgery and 15 patients from the MUA group were excluded: 12 lost to follow-up and 3 deaths. The remaining 96 MUA patients were matched to 288 TKAs who did not require MUA or revision, all with a minimum 2-year follow-up. Patients who underwent MUA were younger (60.7 vs. 66.3 years, p < 0.001) and had less preoperative knee flexion (105.4 vs. 110.7 degrees, p < 0.001). There were five (4.9%) revisions in the MUA group: two instability, two chronic pain, and one arthrofibrosis. There were no differences between the groups with respect to postoperative Knee Society Knee Score, Western Ontario and McMaster Universities Osteoarthritis, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Forgotten Joint Score-12, satisfaction, or complications. Satisfaction rates were 88.5% among MUA patients and 89.6% among non-MUA patients (p = 1.0). Patients undergoing MUA following TKA, using the criteria of failure to achieve 105 degrees of flexion by 6 weeks postoperatively, were able to achieve similar PROMs and satisfaction compared with a control group with a low incidence of revision due to persistent arthrofibrosis.

Extracorporeal Shock Wave and Melatonin Alleviate Joint Capsule Fibrosis after Knee Trauma in Rats by Regulating Autophagy

BACKGROUND

Joint contracture is a common clinical problem affecting joint function. Capsule fibrosis plays a pivotal role in the progression of joint contracture. Previous studies have reported that autophagy plays a regulatory role in visceral fibrosis.

OBJECTIVE

This study aimed to investigate whether extracorporeal shock wave therapy (ESWT) and melatonin alleviate joint capsule fibrosis in rats with extended knee joint contracture by regulating autophagy.

METHODS

A rat traumatic knee joint extension contracture model was made. Then, the rats were treated with ESWT, melatonin, ESWT + melatonin, or ESWT + melatonin + mTOR agonist for 4 weeks. The range of motion (ROM) of the knee joints was measured. Joint capsules were collected and observed for pathological changes by H&E and Masson staining. LC3B protein expression was evaluated by immunofluorescence staining. TGF-β1, MMP-1, Col-Ⅰ, Col-Ⅲ, LC3, ATG7, Beclin1, p-AMPK, p-mTOR and p-ULK1 protein expressions were measured by Western blot assay.

RESULTS

The intervention groups had significantly improved ROM of knee joint (P < 0.05), significantly improved pathological changes on HE and Masson staining, significantly decreased protein expressions of TGF-β1, MMP-1, Col-Ⅰ, Col-Ⅲ and pmTOR (P < 0.05), and significantly increased protein expressions of LC3B, LC3II/LC3I ratio, ATG7, Beclin1, p-AMPK, and p-ULK1 (P < 0.05). Among these groups, the effects demonstrated by the ESWT + melatonin group were the best. With the mTOR agonist supplement, the therapeutic effects of extracorporeal shock waves and melatonin were significantly reduced.

CONCLUSION

ESWT plus melatonin alleviated knee joint capsule fibrosis in rats by regulating autophagy.

Functional somatic syndromes are associated with inferior outcomes and increased complications after hip and knee arthroplasty: a systematic review

BACKGROUND

Functional somatic syndromes (FSSs), defined as chronic physical symptoms with no identifiable organic cause, may impact results after hip and knee arthroplasty. The purpose of this study was to perform a systematic review assessing the relationship between FSSs and clinical outcomes after primary total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA).

METHODS

The PubMed and Web of Science databases were queried from January 1955 through December 2021 for studies investigating the impact of at least one FSS (fibromyalgia, irritable bowel syndrome (IBS), chronic headaches, and chronic low back pain) on outcomes after primary THA/TKA/UKA. Outcomes of interest included patient-reported outcome measures (PROMs), postoperative opioid use, complications, revisions, and costs of care.

RESULTS

There were twenty-eight studies, including 768,909 patients, of which 378,384 had an FSS. Five studies reported preoperative PROMs prior to THA/TKA, all of which showed worse PROMs among patients with at least 1 FSS diagnosis. Thirteen studies reported postoperative PROMs after THA/TKA, all of which demonstrated worse PROMs among patients with at least 1 FSS diagnosis. Patients with FSS diagnoses were more likely to continue using opioids at 3, 6, and 12 months following TKA, THA, and UKA. Medical and surgical complications, as well as revision rates, were higher among patients with FSSs.

CONCLUSION

Patients with FSSs have inferior PROMs and are at increased risk for prolonged postoperative opioid use, medical and surgical complications, and revision after hip and knee arthroplasty. Improved understanding of the factors influencing the success of hip and knee arthroplasty is critical. Future studies should address the biopsychosocial determinants of health that can impact outcomes after total joint arthroplasty.

Proximal tibial osteotomy with absorbable spacer combined with fibular osteotomy has similar clinical outcomes to high tibial osteotomy in the treatment of knee osteoarthritis

PURPOSE

Proximal tibia osteotomy with absorbable spacer combined with fibular osteotomy (TPOASI) is an emerging surgical technique for treating knee osteoarthritis (KOA); however, the efficacy of this procedure remains unknown. We hypothesize that TPOASI can achieve similar clinical outcomes to opening-wedge high tibial osteotomy (OW-HTO). The objective of this study is to compare the clinical results between these two procedures.

METHODS

Patients who underwent TPOASI or OW-HTO from July 2016 to September 2020 were included. The following outcome parameters were determined before and after the surgery: the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Knee Injury and Osteoarthritis Outcome Score (KOOS), the visual analogue scale of pain, the Intermittent and Persistent Osteoarthritis Pain Scale, femorotibial angle, and post-operative complications.

RESULTS

In total, 209 cases were analyzed (102 in TPOASI group; 107 in OW-HTO group) with 3.1 years average follow-up. Both procedures achieved significant improvement in KOOS (62.0 to 24.4 in the TPOASI and 62.8 to 26.2 in the OW-HTO group, p < 0.001) and WOMAC score (68.9 to 24.1 in the TPOASI versus 69.9 to 26.1 in the OW-HTO group, p < 0.001). There were no significant differences in complications or femorotibial angle between the two groups but the only significant difference in the outcome parameters was the WOMAC stiffness score (19.6 in the TPOASI versus 26.5 in the OW-HTO group).

CONCLUSION

TPOASI achieves comparable results to OW-HTO in terms of clinical scores, radiographic results, and complications, but has the advantage of avoiding internal fixation removal.

Clinical frailty is independently associated with joint-specific function and health-related quality of life in patients awaiting a total hip or knee arthroplasty

The aims were to assess whether preoperative joint-specific function (JSF) and health-related quality of life (HRQoL) were associated with level of clinical frailty in patients waiting for a primary total hip arthroplasty (THA) or knee arthroplasty (KA). Patients waiting for a THA (n = 100) or KA (n = 100) for more than six months were prospectively recruited from the study centre. Overall,162 patients responded to the questionnaire (81 THA; 81 KA). Patient demographics, Oxford score, EuroQol five-dimension (EQ-5D) score, EuroQol visual analogue score (EQ-VAS), Rockwood Clinical Frailty Score (CFS), and time spent on the waiting list were collected. There was a significant correlation between CFS and the Oxford score (THA r = -0.838; p < 0.001, KA r = -0.867; p < 0.001), EQ-5D index (THA r = -0.663, p =< 0.001; KA r = -0.681; p =< 0.001), and EQ-VAS (THA r = -0.414; p < 0.001, KA r = -0.386; p < 0.001). Confounding variables (demographics and waiting time) where adjusted for using multiple regression analysis. For each 8.5 (THA, 95% CI 7.1 to 10.0; p < 0.001) and 9.9 (KA, 95% CI 8.4 to 11.4; p < 0.001) point change in the Oxford score, there was an associated change in level of the CFS. For each 0.16 (THA, 95% CI 0.10 to 0.22; p < 0.001) and 0.20 (KA, 95% CI 0.12 to 0.27; p < 0.001) utility change in EQ-5D, there was an associated change in level of the CFS. EQ-VAS (THA, B = -11.5; p < 0.001, KA B = -7.9; p = 0.005) was also associated with CFS. JSF and HRQoL in patients awaiting THA or KA for more than six months, were independently associated with level of clinical frailty. With further prospective studies, clinical frailty may prove to be a useful metric to assist in the prioritization of arthroplasty waiting lists.

Comparison of short-time functional outcomes after TKA between Multigen Plus CR and Physica KR prostheses

BACKGROUND

Aim of this study was to compare functional results within 36 months following primary total knee arthroplasty (TKA) using a conventional prosthesis Multigen Plus CR and a new Physica KR implant. Our hypothesis was that the use of the Kinematics-Retaining design of an TKA implant leads to a significantly greater improvement in the active range of motion and better functional results (KSS 1, KSS 2 and WOMAC score) than the conventional CR implant at short-term follow-up.

MATERIALS AND METHODS

We retrospectively analysed data of 234 patients who underwent primary TKA at our hospital from April 2010 to August 2015 with the CR type of implant and from July 2014 to August 2015 with the KR implant due to advanced knee arthrosis of IIIrd and IVth grade of Kellgren-Lawrence classification, with no major ligamentous instability. Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, Knee Society Scores 1 (KSS 1) and 2 (KSS 2) and flexion (AROM) were recorded preoperatively and at 6, 12 and 36 months after surgery.

RESULTS

Our study showed a statistically significant difference in functional results at three years with better KSS 1 score, a tendency to higher values in the KSS 2 score, as well as a statistically significant overall improvement in AROM in favour of the new KR design over the conventional CR implant with a post-hoc power analysis of 83.8%. We found that there was no statistically significant difference between groups when comparing WOMAC score and complications at short-term follow-up.

CONCLUSIONS

Our study provided more favourable clinical results for using Kinematics-Retaining implant in primary TKA. Further studies should focus on radiological and functional outcomes from mid- to long-term follow-up.

Factors associated with subjective knee joint stiffness in people with knee osteoarthritis: A systematic review

INTRODUCTION

Subjective knee stiffness is a common symptom in patients with knee osteoarthritis treated conservatively. However, the influencing factors or effects of knee joint stiffness are unknown. The aim of this study was to explore the factors associated with subjective knee stiffness in patients with knee osteoarthritis.

METHODS

The MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and PEDro databases were searched in November 2021. Prospective or retrospective cohort studies were included. The methodological quality of the selected articles was assessed using the Scottish Intercollegiate Guidelines Network checklist.

RESULTS

Twenty out of 1943 screened articles were included in this systematic review. Eighteen and two studies were rated as having acceptable and low quality, respectively. All the included studies measured subjective knee stiffness using the Western Ontario and McMaster Universities Osteoarthritis Index. The main findings were that worse preoperative subjective knee stiffness was associated with worse pain, subjective knee stiffness, and patient satisfaction at 1 year after total knee arthroplasty. In addition, worse subjective knee stiffness was associated with future degenerative changes in the knee joint, such as joint space narrowing and osteophyte growth progression.

CONCLUSION

Subjective knee stiffness may be associated with the prognosis after total knee arthroplasty and degenerative changes in the knee joint. Early detection and treatment of knee stiffness could lead to a good prognosis after total knee arthroplasty and prevent the progression of degenerative changes in the knee joint.

Correlation Between Patient-Reported "Happiness" With Knee Range of Motion and Objective Measurements in Primary Knee Arthroplasty

BACKGROUND

The purpose of this study was to evaluate the correlation between objective knee range of motion (ROM) and patient "happiness" with knee ROM after total knee arthroplasty.

METHODS

This was a retrospective review of all primary total knee arthroplasties from June through December 2019, yielding 902 patients (1,009 knees). Records were reviewed for knee ROM preoperatively and postoperatively at 6-week follow-up as well as whether patients self-reported being "Happy with their ROM" (HWROM). Clinical records were reviewed for documents ROM as well as manipulation under anesthesia (MUA).

RESULTS

The mean preoperative ROM was 110 ± 16 degrees, and 40% of patients were happy with their ROM. Postoperatively, the mean ROM was 106 ± 13 degrees (P < .001), and 76% of patients were HWROM (P < .001). The mean change in knee ROM was (-) 5 ± 17 degrees. The mean postoperative ROM and change in ROM of patients who were HWROM after surgery were 109 ± 12 degrees and (-)2 ± 16 degrees. In patients not HWROM postoperatively, the mean ROM and change in ROM were 98 ± 14 degrees and (-)12 ± 18 degrees (P < .001). Patients with a lower preoperative ROM were statistically significantly more likely to have a positive change in their HWROM (f ratio = 41, P < .001). MUAs were performed in 7.2% of knees, and 28% of patients who underwent an MUA were HWROM before MUA.

CONCLUSION

Early postoperative knee ROM was correlated with patient HWROM. However, further longer term follow-up and more detailed analysis of patient happiness with ROM are needed.

In Vitro Kinematic Analysis of Single Axis Radius Posterior-Substituting Total Knee Arthroplasty

This is an experimental study. As current posterior-substituting (PS) total knee arthroplasties have been reported to incompletely restore intrinsic joint biomechanics of the healthy knee, the recently designed single axis radius PS knee system was introduced to increase posterior femoral translation and promote ligament isometry. As there is a paucity of data available regarding its ability to replicate healthy knee biomechanics, this study aimed to assess joint and articular contact kinematics as well as ligament isometry of the contemporary single axis radius PS knee system. Implant kinematics were measured from 11 cadaveric knees using an in vitro robotic testing system. In addition, medial collateral ligament (MCL) and lateral collateral ligament (LCL) forces were quantified under simulated functional loads during knee flexion for the contemporary PS knee system. Posterior femoral translation between the intact knee and the single axis radius PS knee system differed significantly (p < 0.05) at 60, 90, and 120 degrees of flexion. The LCL force at 60 degrees (9.06 ± 2.81 N) was significantly lower (p < 0.05) than those at 30, 90, and 120 degrees of flexion, while MCL forces did not differ significantly throughout the range of tested flexion angles. The results from this study suggest that although the contemporary single axis radius PS knee system has the potential to mimic the intact knee kinematics under muscle loading during flexion extension due to its design features, single axis radius PS knee system did not fully replicate posterior femoral translation and ligament isometry of the healthy knee during knee flexion.

Is there a Threshold Preoperative WOMAC Score That Predicts Patient Satisfaction after Total Knee Arthroplasty?

The aim of this study was to identify threshold preoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores that were predictive of patient dissatisfaction 1 year after total knee arthroplasty (TKA). A retrospective cohort of 3,324 patients undergoing a primary TKA was identified from an established arthroplasty database. Patient demographics, comorbidities, and the WOMAC score were collected preoperatively. Patient satisfaction was assessed at 1 year using four questions that focused on: overall outcome, activity, work, and pain. Receiver operating characteristic (ROC) curve analysis was used to identify threshold values predictive of dissatisfaction. The overall satisfaction rate at 1 year was 89.7% (n = 2982). Patients who were satisfied had a significantly greater preoperative pain (3.6, 95% confidence interval [CI] 1.6-5.6, p < 0.001) and functional (4.5, 95% CI 2.6-6.5, p < 0.001) component and total (4.2, 95% CI 2.3-6.0, p < 0.001) WOMAC scores compared with those who were dissatisfied. ROC curve analysis demonstrated the preoperative pain (p = 0.001) and functional (p < 0.001) components and total (p < 0.001) WOMAC scores were significant predictors of satisfaction. Patients scoring < 36 for the pain and function components and < 35 for the total WOMAC score were more likely to be dissatisfied with their overall outcome, but the area under the curves (AUCs) for these predictive threshold values were 0.56, 0.54, and 0.60, respectively, indicating poor prognostic value. A similar finding was observed for satisfaction with pain relief and ability to work and recreational activities; however, in addition the stiffness component was also a significant (p < 0.001) predictor with a threshold value of < 43. Again, these thresholds were of poor prognostic value with an AUC of less than 0.57 for all these satisfaction questions. Threshold values in the preoperative component and total WOMAC scores were not reliable prognostic indicators of overall patient satisfaction or for satisfaction with pain relief, ability to do work, or recreational activities after TKA.

Patient Satisfaction Following Primary Total Knee Arthroplasty: Contributing Factors

The reported dissatisfaction rate after primary total knee arthroplasty (TKA) ranges between 15% and 25%. The purpose of this article is to perform a narrative review of the literature with the aim of answering the following question: What are the main factors contributing to patient dissatisfaction after TKA? A review of the literature was performed on patient satisfaction after TKA. The search engines used were MedLine (PubMed) and the Cochrane Library. The keywords used were "TKA" and "satisfaction". The main reported preoperative factors positively contributing to patient satisfaction were the following: fulfilment of preoperative expectations, preoperative complete joint space collapse, increasing patellar and lateral compartment osteophyte size, and TKA communication checklist. The principal preoperative factors negatively contributing to patient satisfaction included female sex, comorbidities, and Hispanic race. The chief perioperative factor positively contributing to patient satisfaction was cosmetic closure, whereas the fundamental perioperative factors negatively contributing to patient satisfaction included joint laxity, anterior tibial component slope, and greater femoral component valgus angle. The principal postoperative factors positively contributing to patient satisfaction were the following: ameliorated walking distance, improved range of motion, and improvements in pain. The most important postoperative factors negatively contributing to patient satisfaction included poor postoperative knee stability and soft-tissue balance, functional limitation, surgical complication and reoperation, staff or quality of care issues, and increased stiffness.

A new prediction model for patient satisfaction after total knee arthroplasty and the roles of different scoring systems: a retrospective cohort study

BACKGROUND

Although total knee arthroplasty (TKA) is an efficacious treatment for end-stage osteoarthritis, ~20% of patients are dissatisfied with the results. We determined which factors contribute to patient satisfaction and compared the various scoring systems before and after surgery.

METHODS

In this retrospective cohort study, 545 patients were enrolled and evaluated preoperatively and 1 year postoperatively. Patient demographics, as well as scores for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form (SF)-12, and 1989 Knee Society Clinical Rating System (1989 KSS), were recorded preoperatively and postoperatively. The possible predictors were introduced into a prediction model. Scores for overall satisfaction and the 2011 Knee Society Score (2011 KSS) were also assessed after TKA to identify the accuracy and agreement of the systems.

RESULTS

There were 134 male patients and 411 female patients, with an overall prevalence of satisfaction of 83.7% 1 year after surgery. A history of surgery (p < 0.001) and the 1989 KSS and SF-12 were of the utmost importance in the prediction model, whereas the WOMAC score had a vital role postoperatively (change in WOMAC pain score, p < 0.001; change in WOMAC physical function score, p < 0.001; postoperative WOMAC pain score, p = 0.004). C-index of model was 0.898 > 0.70 (95% confidence interval (CI): 0.86-0.94). The Hosmer-Lemeshow test showed a p value of 0.586, and the AUC of external cohort was 0.953 (sensitivity=0.87, specificity=0.97). The agreement between the assessment of overall satisfaction and the 2011 KSS satisfaction assessment was general (Kappa=0.437 > 0.4, p < 0.001).

CONCLUSION

A history of surgery, the preoperative 1989 KSS, and the preoperative SF-12 influenced patient satisfaction after primary TKA. We recommend the WOMAC (particularly the pain subscale score) to reflect overall patient satisfaction postoperatively.

Causes of stiffness after total knee arthroplasty: a systematic review

BACKGROUND

Knee stiffness after total knee arthroplasty (TKA) often leads to pain and discomfort, failing to meet patients' expectations on the surgical procedure. Despite the growing debate on the topic, a comprehensive literature analysis of stiffness causes has never been conducted. Thus, the purpose of the present study was to systematically review the literature regarding the main causes of stiffness after TKA.

METHODS

Pubmed Central, Scopus, and EMBASE databases were systematically reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines for studies on stiffness and pain or discomfort after TKA through November 2020. Overall, 25 articles matched the selection criteria and were included in the study. Clinical relevance and strength of evidence of the included studies were graded using the risk of bias and the methodological index for non-randomized studies quality assessment tools.

RESULTS

The main causes of pain and discomfort due to stiffness were surgery-related issues, i.e., component malpositioning and over-voluming, implant loosening, psychological distress, and obesity, which could be considered "modifiable" factors, and expression of profibrotic markers, high material hypersensitivity-related cytokines level, male gender, previous contralateral TKA, and high pre-operative pain, which could be considered "non-modifiable" factors.

CONCLUSION

The use of alternative technologies such as surgical robots, anatomy-based devices, and more inert and less stiff component materials could help in reducing stiffness caused by both modifiable and even some non-modifiable factors. Furthermore, early diagnostic detection of stiffness onset could consistently support surgeons in patient-specific decision-making.

Revision total knee arthroplasty versus primary total knee arthroplasty: a matched cohort study

Introduction

The primary aim of this study was to describe a baseline comparison of early knee-specific functional outcomes following revision total knee arthroplasty (TKA) using metaphyseal sleeves with a matched cohort of patients undergoing primary TKA. The secondary aim was to compare incidence of complications and length of stay (LOS) between the two groups.

Methods

Patients undergoing revision TKA for all diagnoses between 2009 and 2016 had patient-reported outcome measures (PROMs) collected prospectively. PROMs consisted of the American Knee Society Score (AKSS) and Short-Form 12 (SF-12). The study cohort was identified retrospectively and demographics were collected. The cohort was matched to a control group of patients undergoing primary TKA.

Results

Overall, 72 patients underwent revision TKA and were matched with 72 primary TKAs with a mean follow-up of 57 months (standard deviation (SD) 20 months). The only significant difference in postoperative PROMs was a worse AKSS pain score in the revision group (36 vs 44, p = 0.002); however, these patients still produced an improvement in the pain score. There was no significant difference in improvement of AKSS or SF-12 between the two groups. LOS (9.3 days vs 4.6 days) and operation time (1 hour 56 minutes vs 1 hour 7 minutes) were significantly higher in the revision group (p < 0.001). Patients undergoing revision were significantly more likely to require intraoperative lateral release and postoperative urinary catheterisation (p < 0.001).

Conclusion

This matched-cohort study provides results of revision TKA using modern techniques and implants and outlines what results patients can expect to achieve using primary TKA as a control. This should be useful to clinicians counselling patients for revision TKA.

Predictors of chronic pain and level of physical function in total knee arthroplasty: a protocol for a systematic review and meta-analysis

INTRODUCTION

One in five patients undergoing total knee arthroplasty (TKA) experience unchanged or worse pain and physical function 1 year after surgery. Identifying risk factors for unfavourable outcomes is necessary to develop tailored interventions to minimise risk. There is a need to review more current literature with updated methodology that addresses the limitations of earlier systematic reviews and meta-analyses. We present a Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols compliant protocol for a systematic review and meta-analysis of predictors of chronic pain and impaired function after TKA.

METHODS AND ANALYSIS

This review will include prospective longitudinal observational studies, or randomised trials (including cluster and crossover designs) that report arm-wise predictors of chronic postsurgical pain or impaired physical function at 3 months, 6 months or 12 months. A comprehensive literature search of studies published between 2000 and 2019 will be performed in Medline, Embase, CINAHL, Cochrane Library and PEDro. Blinded assessment with consensus agreement will be applied for inclusion of studies, data extraction and assessment of bias risk (Quality in Prognosis Studies tool). The co-primary outcomes, pain and impaired function, at 12 months after TKA will be analysed separately. Estimates of association between each outcome and any preoperative or intraoperative factor that may predict chronic pain or impaired physical function will be extracted from the included studies, where possible. For randomised studies, results will only be extracted from TKA arms (or the first period of crossover trials). Estimates of association from the primary evidence will be synthesised narratively, and quantitatively using multivariate meta-analysis to provide 'pooled' estimates of association. Subgroup and sensitivity analyses will be performed. Certainty of evidence for each predictor will be derived from the Grading of Recommendations Assessment, Development and Evaluation framework.

ETHICS AND DISSEMINATION

No ethical issues are associated with this project. The results from this review will be published in peer-reviewed journals and presented at international conferences.

PROSPERO REGISTRATION NUMBER

CRD42018079069.

One-year Oxford knee scores should be used in preference to 6-month scores when assessing the outcome of total knee arthroplasty

Purpose

The primary aim of this study was to assess whether there was a clinically significant difference in the mean Oxford knee score (OKS) between 6 and 12 months after total knee arthroplasty (TKA). The secondary aim was to identify variables associated with a clinically significant change in the OKS between 6 and 12 months.

Methods

A retrospective cohort study was undertaken using an established arthroplasty database of 1574 primary TKA procedures. Patient demographics, body mass index (BMI), comorbidities, OKS and EuroQoL 5-domain (EQ-5D) score were collected preoperatively and at 6 and 12 months postoperatively. A clinically significant change in the OKS was defined as 5 points or more.

Results

There was a 1.1-point increase in the OKS between 6 and 12 months postoperatively, which was statistically significant (95% confidence (CI) 0.8–1.3, p < 0.0001). There were 381 (24.2%) patients who had a clinically significant improvement in their OKS from 6 to 12 months. After adjusting for confounding, patients with a lower BMI (p = 0.028), without diabetes mellitus (p < 0.001), a better preoperative OKS (p < 0.001) or a worse 6-month OKS (p < 0.001) were more likely to have a clinically significant improvement. A 6-month OKS < 36 points was a reliable predictor of a clinically significant improvement in the 6-month to 12-month OKS (area under the curve 0.73, 95% CI 0.70–0.75, p < 0.001).

Conclusion

Overall, there was no clinically significant change in the OKS from 6 to 12 months; however, a clinically significant improvement was observed in approximately a quarter of patients and was more likely in those scoring less than 36 points at 6 months. Level of evidence: retrospective diagnostic study, level III.

There is no clinically important difference in the Oxford knee scores between one and two years after total knee arthroplasty: The one-year score could be used as the benchmark timepoint to assess outcome

BACKGROUND

The aim was to assess the whether there was a clinically important change in the Oxford knee score (OKS) between one and two years after total knee arthroplasty (TKA), and to identify predictors associated with a clinically important change.

METHODS

A retrospective cohort study was undertaken using an established arthroplasty database of 5857 primary TKA. Patient demographics, body mass index, social deprivation, OKS and EuroQoL five-domain (EQ-5D) score were collected preoperatively and at one and two years postoperatively. A clinically important change in the OKS was defined as ≥5 points.

RESULTS

There was a 0.2 point increase in the OKS between one and two years, which was statistically significant (95% confidence interval (CI) 0.1 to 0.4, p < .0001), but not clinically important. A better preoperative OKS (p < .001) and in contrast a worse one year OKS (p < .001) were independently associated with a greater improvement from one to two years. There were 1006 (17.3%) patients that had a clinically important improvement in the OKS between one and two years. Receiver operating characteristic curve analysis showed that a one year OKS of less than 35 was a reliable predictor of a clinically important improvement between one and two years (area under the curve 0.77, 95% CI 0.76 to 0.78, p < .001).

CONCLUSION

There was not a clinically important change in the OKS from one to two years after TKA when assessed as a group. However, individual patients with a one year OKS of less than 35 may demonstrate a clinically important improvement at two years.

LEVEL OF EVIDENCE

Retrospective diagnostic study, Level III.

Long-Term Outcome Following Revision Total Knee Arthroplasty is Associated With Indication for Revision

BACKGROUND

There is limited information about long-term clinical outcomes following revision total knee arthroplasty (TKA) in relation to the indication for revision. Previously, a clear relation between indication for revision and clinical outcome was shown after 2 years. Present study evaluated (1) whether the reported association at 2 year remains present at 7.5 years, and (2) how clinical outcome at 7.5 years developed compared to baseline and 2-year follow-up, and (3) whether patients had additional adverse events.

METHODS

A cohort of 129 patients with a total system revision TKA was selected. Range of motion, Visual Analog Scale for pain and satisfaction, and clinical and functional Knee Society Score were obtained preoperatively, at 3 months, 1, 2, and 7.5 years. Reasons for revision were septic loosening, aseptic loosening, malposition, instability, and severe stiffness.

RESULTS

Patients revised for severe stiffness had significantly worse outcomes. No difference was found between the other indications. The clinical outcome after revision TKA at 7.5 years remained stable for septic and aseptic loosening, malposition, and instability but deteriorated slightly for the severe stiffness group. Visual Analog Scale satisfaction remained constant for all indications. There were 11 additional complications between 2- and 7.5-year follow-up, 9 of which necessitated reoperation.

CONCLUSION

All indications except severe stiffness had a similar clinical outcome which was maintained up to 7.5-year follow-up. The severe stiffness group had worse outcomes and deteriorated slightly at longer follow-up. Outcome at 3 months seems predictive for long-term outcome. Additional complications did not differ significantly for the different reasons for revision.

LEVEL OF EVIDENCE

Level III, prognostic study.

Patients' experiences of discontentment one year after total knee arthroplasty- a qualitative study

Background

Total knee arthroplasty is a common procedure with generally good results. However, there are still patients who are dissatisfied without known explanation. Satisfaction and dissatisfaction have previously been captured by quantitative designs, but there is a lack of qualitative studies regarding these patients’ experiences. Qualitative knowledge might be useful in creating strategies to decrease the dissatisfaction rate.

Methods

Of the 348 patients who responded to a letter asking if they were satisfied or dissatisfied with their surgery, 61 (18%) reported discontent. After excluding patients with documented complications and those who declined to participate, semi-structured interviews were conducted with 44 patients. The interviews were analyzed according to qualitative content analysis. The purpose was to describe patients’ experiences of discontentment 1 year after total knee arthroplasty.

Results

The patients experienced unfulfilled expectations and needs regarding unresolved and new problems, limited independence, and lacking of relational supports. They were bothered by pain and stiffness, and worried that changes were complications as a result of surgery. They described inability to perform daily activities and valued activities. They also felt a lack of relational supports, and a lack of respect and continuity, support from health care, and information adapted to their needs.

Conclusion

Patient expectation seems to be the major contributing factor in patient discontentment after knee replacement surgery. This qualitative study sheds light on the on the meaning of unfulfilled expectations, in contrast to previous quantitative studies. The elements of unfulfilled expectations need to be dealt with both on the individual staff level and on the organizational level. For instance, increased continuity of healthcare staff and facilities may help to improve patient satisfaction after surgery.

Diabetes mellitus does not increase the risk of knee stiffness after total knee arthroplasty: a meta-analysis of 7 studies including 246 053 cases

Purpose

Methods

Results

Conclusion

Level of evidence

Comparison of the accelerometer-based navigation system with conventional instruments for total knee arthroplasty: a propensity score-matched analysis

BACKGROUND

The accelerometer-based navigation (ABN) system is an emerging navigation system for total knee arthroplasty (TKA). This study aimed to determine whether the ABN system could improve the accuracy of mechanical alignment, component positioning, and short-term clinical outcomes for TKA when compared to conventional instruments (CON).

METHODS

A total of 204 patients were selected and divided into two groups (CON: 135, ABN: 69) after applying the inclusion and exclusion criteria. Then, 1:1 propensity score matching was performed for age, gender, body mass index, hip-knee-ankle angle (HKA), Knee Society Score (KSS), Western Ontario and McMaster Universities (WOMAC) score, and follow-up times. A total of 82 consecutive patients (82 knees) underwent total knee arthroplasty using ABN (n = 41) or CON (n = 41) were enrolled in this study. The postoperative HKA, frontal femoral component (FFC) angle, frontal tibial component (FTC) angle, lateral femoral flexion (LFF) angle, and lateral tibial component (LTC) angle were compared between the two groups to evaluate mechanical alignment and component positioning. Additional clinical parameters, including haemoglobin reduction, the KSS, and the WOMAC score, were assessed at the final follow-up (the mean follow-up period was 20.9 months in the CON group and 21.2 months in the ABN group).

RESULTS

The ABN group had a significantly improved mean absolute deviation of HKA (P = 0.033), FFC (P = 0.004), FTC (P = 0.017), LFF (P = 0.023), and LTC (P = 0.031) compared to those of the CON group. The numbers of FFCs and LTCs within 3° were significantly different (P = 0.021, P = 0.023, respectively) between the two groups. However, no differences in the numbers of FTCs within 3° (P = 0.166) and LFF within 3° (P = 0.556) were found. The ABN group had a significantly higher KS function score (P = 0.032), and the pain and stiffness scores were significantly different (P = 0.034, P = 0.020, respectively) between the two groups. Moreover, the ABN system could reduce hidden blood loss postoperatively. However, no difference was found in the KS knee score and the total WOMAC score between the two groups.

CONCLUSION

This study demonstrates that ABN system improved TKA mechanical alignment and component positioning and decreased the hidden blood loss postoperatively compared to conventional instruments. However, no significant differences were found in short-term clinical outcomes between ABN and conventional instruments at the final follow-up. However, whether this system contributes to revision rates and long-term clinical outcomes requires further study.

Improved clinical outcomes after revision arthroplasty with a hinged implant for severely stiff total knee arthroplasty

PURPOSE

Management of the severely stiff total knee arthroplasty (TKA) is challenging, with the outcome of revision arthroplasty being inferior compared to the outcome for other indications. The aim of this study was to analyse the outcome after revision TKA with hinged-type implants for severely stiff TKA [range of motion (ROM) ≤ 70°] at 2 years.

METHODS

A cohort of 38 patients with a hinged-type revision TKA (Waldemar Link or RT-Plus) and preoperative ROM ≤ 70° were selected from a prospectively collected database. ROM, visual analogue scale (VAS) for pain and satisfaction and Knee Society Score (KSS) were obtained preoperatively and at 3 months, 1 year and 2 years. Pre- and postoperative outcome were compared at 2 years.

RESULTS

There was a significant increase in ROM and KSS. VAS pain scores did not differ significantly. The median ROM at 2 years was 90° (range 50°-125°) with a median gain of 45° (range 5°-105°). Median VAS pain was 28.5 (range 0-96) points and median VAS satisfaction was 72 (range 0-100) points at 2 years. Twelve patients suffered a complication. Recurrent stiff knee was the most frequently reported complication (n = 5).

CONCLUSIONS

Hinged-type revision TKA following a severely stiff TKA renders a significant, although moderate, clinical improvement at 2 years.

LEVEL OF EVIDENCE

Retrospective case series. Level IV.

The negative effect of joint line elevation after total knee arthroplasty on outcome

PURPOSE

Total knee arthroplasty (TKA) is widely used as a treatment for knee osteoarthritis. However, still up to 20% of the patients are dissatisfied. Joint line elevation after TKA might be a contributing factor as it alters knee kinematics. The aim of this study was to investigate the effect of joint line elevation on outcome.

METHODS

A systematic review of the literature was performed to select studies that reported on joint line alterations after primary or revision TKA and outcome. Studies with comparable outcome parameters were included in a correlation analysis.

RESULTS

In total, 396 studies were identified, of which 27 met the inclusion criteria. 8 studies could be included in the correlation analysis. Mean joint line elevation after primary TKA was 3.0 mm and after revision TKA this was 3.6 mm. A statistically significant negative correlation was found between joint line elevation and the postoperative Knee Society Score (KSS) function score (ρ = - 0.496, p < 0.001). In a pooled analysis, the maintained joint line revision TKA group had statistically significant better postoperative KSS total scores compared to an elevated joint line group (p < 0.001).

CONCLUSION

In this systematic review, a negative correlation between joint line elevation and outcome was found. Furthermore, revision TKAs with a maintained joint line have statistically significant better postoperative KSS scores compared to an elevated joint line group. To achieve optimal outcome after TKA, restoration of the joint line is one of the parameters that should be pursued and introduced elevation should not exceed 4 mm.

LEVEL OF EVIDENCE

IV.

How do orthopaedic surgeons inform their patients before knee arthroplasty surgery? A cross-sectional study

Background

Total knee arthroplasty (TKA) is a successful and common procedure. However, 6–28% of patients are dissatisfied postoperatively. The provision of preoperative patient information, inquiring about patients’ expectations, and taking a psychiatric history are essential parts of both preoperative evaluation and postoperative outcome. The aim of this study was to investigate how orthopaedic knee surgeons in Sweden inform their patients before surgery.

Methods

A questionnaire was distributed to all knee surgeons performing TKA in Sweden. Responses were received from 60 of the 65 orthopaedic departments performing TKA in Sweden (92%), covering 219 of the approximately 311 knee surgeons at the 65 departments (70%). The answers were analysed with descriptive statistics. A content analysis of the surgeons’ opinions was also performed using a thematic method.

Results

In terms of information provision, 58% of the surgeons always gave written information while 92% informed orally. Only 44% always asked about the patient’s expectations, and only 42% always informed patients about the 20% dissatisfaction rate after TKA. Additionally, 24% never operated on mild indication of arthrosis, 20% always took a psychiatric history, and half never or seldom consulted a psychiatrist. However, all the knee surgeons believed in a psychiatric impact on TKA outcome. Qualitative analysis revealed five common causes of patient dissatisfaction, which in descending frequency were: patients’ expectations, choice of patients to operate on, surgical factors, combinations of factors, and insufficient information provision to patients.

Conclusions

Knee surgeons in Sweden have considerable awareness of the importance of preoperative patient information, the impact of patient expectations, and psychiatric illness. However, they need to improve their preoperative routines when it comes to providing written information, asking about the patient’s expectations, and psychiatric assessment.