Socioeconomic Status Affects Patient-Reported Outcome Measures in Total Hip and Knee Arthroplasty: A Retrospective Dutch Registry Study

BACKGROUND

To determine the association between socioeconomic status (SES) and patient-reported outcome measures in a Dutch cohort who have undergone total hip arthroplasty (THA) or total knee arthroplasty (TKA).

METHODS

A retrospective national registry study of all patients who underwent primary THA or TKA between 2014 and 2020 in the Netherlands was performed. Linear mixed effects regression models were used to assess the association between SES and patient-reported outcome measures for THA and TKA patients separately. The following measures were collected: numeric rating scale for pain, Oxford Hip/Knee Score, Hip/Knee disability and Osteoarthritis Outcome Score, and the EuroQol 5-Dimensions questionnaire. Sex, age, body mass index, American Society of Anesthesiologists classification, Charnley classification, and smoking status were considered as covariates in the models.

RESULTS

THA patients (n = 97,443) were on average 70 years old with a body mass index of 27.4 kg/m2, and TKA patients (n = 78,811) were on average 69 years old with a body mass index of 29.7 kg/m2. Preoperatively, patients with a lower SES undergoing THA or TKA reported more severe symptoms and lower health-related quality of life. At 1-year follow-up, they also reported lower scores and less improvement over time compared to patients with a higher SES.

CONCLUSIONS

Patients with lower SES report worse symptoms when admitted for surgery and less improvement after surgery. Future research must address potentially mediating factors of the association between SES and symptom reporting such as access to surgery and rehabilitation, subjectivity in reporting, and patient expectation for THA and TKA outcomes.

Permissive Weight Bearing in Proximal Humeral Fracture Management: A Survey-Based Inquiry in the Netherlands

Purpose Proximal humeral fractures (PHF) are common, particularly among the elderly due to low-energy trauma. Adequate rehabilitation is essential for functional recovery, whether through conservative or surgical treatment. Permissive weight bearing (PWB) is a relatively new rehabilitation concept, characterized by earlier mobilization of the affected limb/joint after trauma. Multiple studies demonstrated the value of PWB for the lower extremities, but this has not been translated to the upper extremity (i.e. PHF). Therefore, our aim was to investigate the current state and variability of rehabilitation of PHF and the role of implementing PWB principles in aftercare. Materials and methods An online survey, comprising 23 questions about the treatment of PHF, was distributed amongst an estimated 800 Dutch orthopaedic and trauma surgeons via the Dutch Orthopaedic and Dutch Trauma Society newsletter from May 2021 until July 2021. Results Among 88 respondents (n=69 orthopaedic, n=17 trauma surgeons, and n=2 other), most recommended early post-trauma mobilization (<6 weeks). Additionally, 53.4% (n=49) advised starting load bearing after six weeks for conservatively treated patients and 59.8% (n=52) for operative treatment. A wide variation of exercises used after immobilization was found in both groups. The usage of a sling after operative treatment was advised by 86% (n=74) of all 86 respondents. Conclusions The present study found limited consensus about PHF aftercare and the implementation of weight-bearing principles. The majority recommended early mobilization and advised the usage of a sling. A protocol capable of accommodating the diversity in aftercare (e.g. fracture type) is essential for maintaining structured rehabilitation, with PWB emerging as a promising example. More prospective studies are needed to form an evidence-based protocol focusing on the aftercare of PHF.

Perioperative Differences Between Outpatient and Inpatient Pathways Following Hip and Knee Arthroplasty

Background

Optimization of clinical pathways and logistics led to the introduction of outpatient joint arthroplasty of the hip and knee. Nevertheless, little is known about what these current protocols look like and how they differ from "standard" inpatient protocols. This study aimed to find preoperative, intraoperative, and postoperative differences between outpatient and inpatient pathways.

Methods

A questionnaire (ranging between 23 and 37 items) was developed and administered by email to orthopedic surgeons who were a member of the Dutch Hip Society and Dutch Knee Society. Survey response rate was 38% (N = 117).

Results

No significant differences were found in preoperative pathway characteristics. The administration regime for tranexamic acid significantly differed between outpatient and inpatient pathways (P < .001 and P = .002 for hip and knee arthroplasty, respectively), with outpatient pathways using a combined (eg, oral and intravenous) administration regime more frequently. The perioperative antibiotic prophylaxis regime also significantly differed between outpatient and inpatient pathways (P < .001 and P = .014, respectively), with outpatient pathways more frequently incorporating fewer antibiotic doses. Same-day postoperative mobilization significantly less often occurred if surgery took place later that day in inpatient hip arthroplasty pathways (24%; P = .034). Postoperative hemoglobin-check occurred significantly more often on indication in outpatient than in inpatient hip and knee arthroplasty pathways (∼75% vs ∼25%; P = .001).

Conclusions

Few intraoperative and postoperative differences in outpatient and inpatient pathways were found and probably mainly relied on logistical grounds. Nonetheless, findings suggested that outpatient pathways tended to be more up-to-date and innovative than inpatient pathways.

Permissive Weight Bearing in Patients With Surgically Treated Periprosthetic Femoral Fractures Around Total Hip Arthroplasty: A Scoping Review

Periprosthetic femoral fractures (PPFF) around total hip arthroplasty (THA) are one of the leading causes of hip revision. High mortality rates are observed after revision in case of PPFF around THA. To modify risk factors, early postoperative mobilization is necessary. Permissive weight bearing (PWB) is designed to optimize clinical recovery in aftercare. This study aimed to perform a scoping review to summarize the current available evidence on postoperative weight bearing in late PPFF around THA and the implementation of PWB in aftercare. A systematic search was performed on the Cochrane Library, Web of Science, Ovid MEDLINE, EMBASE, and CINAHL databases on January 26th, 2023. Articles were screened in two stages by two independent reviewers. Studies describing adult patients with a history of primary THA who were surgically treated for late PPFF and mentioning prescribed postoperative weight-bearing protocols with relevant outcome measures were included. Seven studies were included, reporting data on 22 patients (age range 47-97 years, BMI range 19-32 kg/m2, ASA classification range 2-3). No studies used PWB in aftercare. The non-weight-bearing group showed no complications. The restricted weight-bearing group had one death and one implant failure. The full weight-bearing group experienced one deep infection and one plate removal because of impingement. The main finding was that, after an extensive systematic search, no articles could be included focusing on PWB in patients with a late PPFF after THA. Addressing this gap in the literature is essential to advancing the understanding of postoperative weight-bearing protocols and PWB for late PPFF around THA.

First long-term analysis of survival and clinical outcome in patient-specific instrumentation for total knee arthroplasty: follow-up of a prospective cohort study

Patient-specific instrumentation (PSI) was introduced to improve post-operative alignment, and consequently the revision rate and clinical results after total knee arthroplasty (TKA). Short- to mid-term data are conflicting regarding these theoretical advantages of PSI. The purpose of this retrospective analysis was to evaluate the survival rate and clinical outcome in PSI TKA 8.4 years after initial surgery. To our knowledge, no other study investigated long-term follow-up of TKA procedures using PSI. From a total cohort of 184 consecutive patients (200 TKA) 136 patients (144 TKA, 72%) were prospectively analysed at a mean follow-up of 8.4 years (±0.4). A survival analysis with all-cause revision of TKA as endpoint was performed. Patient-reported outcome measures (PROMs) were obtained preoperatively and after 1-, 2-, 5-, and 8.4-years of follow-up. Differences between these moments of follow-up were analysed. At final follow-up, 4 TKAs (2%) had undergone revision, all between 2-4 years after primary surgery. Reasons for revision were late infection, aseptic loosening, instability and polyethylene insert breakage. The median score of certain PROMs (WOMAC, VAS, EQ-index, EQ-VAS) decreased compared to previous follow-up scores but were significantly higher than preoperative scores. After 8.4 years of follow-up, no additional revision surgery was performed compared to 5-years postoperatively. Certain PROMs at 8.4-year follow-up decreased compared to earlier moments of follow-up, but all PROMs improved compared to preoperative PROMs.

Nasal hyperreactivity in allergic rhinitis and chronic rhinosinusitis with polyps: a role for neuronal pathways

BACKGROUND

Nasal hyperreactivity (NHR) is prevalent in all chronic upper airway inflammatory phenotypes, including allergic rhinitis (AR) and chronic rhinosinusitis with nasal polyps (CRSwNP). Although NHR in patients with non-allergic rhinitis is mediated by neuronal pathways, AR and CRSwNP are mainly characterized by type 2 inflammation.

METHODS

Eighteen healthy controls and 45 patients with symptomatic AR/CRSwNP underwent a cold, dry air (CDA) provocation test for objective diagnosis of NHR. Before and after, questionnaires were filled out and nasal secretions and biopsies were collected. Markers for neurogenic inflammation (substance P, calcitonin gene-related peptide, neurokinin A), epithelial activation (IL-33), and histamine were measured in secretions by ELISA; and expression of neuronal markers PGP9.5, TRPV1, and TRPM8 was studied in biopsies by RT-q-PCR. Effects of histamine on TRPV1/A1 were studied with Ca2+-imaging using murine trigeminal neurons.

RESULTS

CDA-provocation reduced peak nasal inspiratory flow (PNIF) of patients with subjective NHR but not of non-NHR controls/ patients (p.

Prospective randomized controlled trial: early weight bearing after conservative treatment of Weber B ankle fractures (pancake trial)

PURPOSE

Different studies have shown that weightbearing is safe in stable transsyndesmotic, isolated lateral simple ankle fractures. Despite this evidence, AO guidelines still recommend immobilization with above-the-knee cast for 4-6 weeks for these fractures. The objective of this study was to compare the outcomes of mobilization and weightbearing to those of immobilization and non-weightbearing in patients with stable transsyndesmotic, lateral isolated simple ankle fractures.

METHODS

Fifty patients were randomly assigned to permissive weightbearing in a walking boot or non-weightbearing immobilization using a below-the-knee cast. Primary outcome was ankle functionality as scored by the Olerud-Molander Ankle Score (OMAS). Secondary outcomes were radiological displacement of fracture, range of motion (ROM), calf circumference, and RAND 36-item health survey. Patients were in follow-up for 24 months.

RESULTS

Ankle functionality after six and twelve weeks was significantly higher for the intervention group, with respectively 30 points (p = 0.001) and 10 points (p = 0.015) of difference. ROM improved significantly in the intervention group after six weeks. All fractures showed radiological progression of fracture healing. RAND 36-item showed differences in both physical (60.3 vs. 46.3, p = 0.017) and mental (78.5 vs. 58.2, p = 0.034) components in favor of the intervention group. In 16% of patients who initially showed stable fractures on radiographic imaging, joint dislocation was identified on weightbearing radiographs prior to randomization, leading to exclusion.

CONCLUSION

Weightbearing and mobilization using a walking boot may be a safe treatment for patients with stable Weber B fractures.

Survival rates of anatomically shaped and tapered slip cemented femoral implants: an analysis of 76,281 femoral implants of the Dutch arthroplasty register (LROI)

INTRODUCTION

In cemented total hip arthroplasty (THA) various shapes and geometries of femoral implants are in use. Collarless, polished, and tapered (CPT) implants, and anatomically shaped (AS) implants are most commonly used. Due to their different design features, this might lead to different survival outcomes. In this register-based study, overall implant survival and short-term complications of CPT and AS cemented implants were evaluated.

METHODS

Data of the Dutch Arthroplasty Register (LROI) were used. Cemented femoral implants, which could be classified as CPT or AS were included in this study. Implants were excluded when no classification could be made or if implanted <100 times. Survival analyses were performed using Kaplan-Meier survival analysis and multivariable Cox-proportional hazard analysis.

RESULTS

76,281 cemented THAs were included. At a mean of 5.1 years follow-up (SD 3.1, range 0-12 years), the overall survival of the AS implants was higher compared with the CPT implants, with a survival, of 99.2% and 99.0% respectively (log-rank; p < 0.001). Multivariable regression analysis revealed a higher rate for revision because of loosening of the AS implants (HR 2; CI, 1.4-3.1). AS implants had a lower rate for periprosthetic fractures compared with the CPT implants (HR 0.13; CI, 0.07-0.23).

CONCLUSIONS

Both designs show excellent overall survival rates at short-term follow-up. There is a higher overall survival of AS implants when compared with CPT implants. Revision for implant loosening, however, was statistically significantly higher in AS implants when compared with the CPT implants.

Less wear in deep-dished mobile compared to fixed bearing total knee arthroplasty of the same design at 5-year follow-up: a randomised controlled model-based Roentgen stereophotogrammetric analysis trial

PURPOSE

The aim of this prospective randomised controlled study was to compare wear characteristics and functional outcome between deep-dished mobile bearing (MB) and fixed bearing (FB) cemented total knee arthroplasty (TKA). We hypothesised that deep-dished MB reduces polyethylene wear and improves patient-reported outcome measures.

METHODS

A total of 50 patients were randomised to receive a MB or FB tibia component of the same cemented TKA design. Patients were evaluated over a 5-year follow-up period. Medial and lateral wear were assessed using model-based Roentgen Stereophotogrammetric Analysis (RSA) and compared with the direct postoperative minimal joint space measurement. Functional outcome was assessed by the clinician-derived KSS and OKS, WOMAC, LEAS, and FJS-12. All data were derived using a general linear mixed model.

RESULTS

At 5-year follow-up, decreased wear in the MB compared to the FB group was observed on the lateral side (0.07 ± 0.17 mm, p = 0.026), but not on the medial side (0.31 ± 0.055 mm, p = 0.665). Functional outcomes improved with a statistical significant effect over time, with no significant differences between groups (all p > 0.17).

CONCLUSION

This model-based RSA study with 5-year follow-up showed that cemented deep-dished MB reduced lateral polyethylene wear as compared to FB in a single TKA system, whilst clinical outcomes were comparable. Longer follow-up is needed to establish clinical implications of these altered wear patterns and determine type of wear.

LEVEL OF EVIDENCE

Level 1 randomised controlled trial.

The relationship between plate prominence and need for removal after volar plate osteosynthesis of distal radius fractures

PURPOSE

This study aimed to assess the incidence of plate-related complications and the need for plate removal after volar plate osteosynthesis of the distal radius in relation to Soong classification.

METHODS

All consecutive patients (age > 16 years) in our level II trauma center treated with plate osteosynthesis for distal radius fractures from January 2017 until June 2019 were retrospectively evaluated. The main outcome measures were volar plate positioning according to Soong classification and incidence of plate removal. In addition, the incidence of tendon ruptures, reasons for volar plate removal, and improvement of complaints after removal were evaluated.

RESULTS

The overall incidence of plate removal in the 336 included patients was 16.9% (n = 57). Removal incidence in Soong 2 plates (28.2%) was significantly higher compared to Soong 0 and 1 plates (8.0% and 14.4%, respectively), P = 0.003. Multivariable binary logistic regression analysis showed Soong grade 2 as an independent predictor for plate removal, OR 4.3 (95% CI 1.4-13.7, P = 0.013). Four cases of flexor and four cases of extensor tendon rupture were reported, all in Soong 2 grade plating. The main reasons for volar plate removal were pain (42%) and reduced functionality (12%). In cases where pain was the main reason for removal, 81% of patients reported a decrease in pain during follow-up after surgery.

CONCLUSIONS

This study suggests an association between plate prominence graded by Soong and plate removal using a single plating system. Plate prominence should be reduced in volar plating whenever technically feasible.

Postoperative Load Bearing in Periprosthetic Femoral Fractures Around Hip Arthroplasty: A Survey Among Orthopedic Surgeons in the Netherlands

INTRODUCTION

Permissive weight bearing (PWB) has relatively recently been implemented to optimize rapid clinical recovery and restoration of function in patients suffering lower extremity fractures. PWB shows outcome advantages in this patient category. Currently, there are no decisive recommendations on postoperative load-bearing management after surgically treated periprosthetic femoral fractures (PPFF) around hip arthroplasty. The objective is to investigate the current postoperative practice of weight-bearing instructions for patients with surgically treated PPFF, accounting for differences in types of periprosthetic fractures and treatment options among Dutch orthopedic surgeons.

MATERIALS AND METHODS

An online survey was distributed among the members of the hip and trauma working groups of the Dutch Orthopedic Association.

RESULTS

The response rate was 13% (n=75). The main finding was that postoperative load bearing regimes in Vancouver A, B, and C PPFFs differed greatly among Dutch orthopedic surgeons, and there was no decisive guideline or consensus in postoperative load bearing regimes after surgically treated PPFF was used in the Netherlands.

CONCLUSION

In the absence of decisive guidelines or consensus, more research is needed to explore the efficacy of PWB after surgically treated PPFF.

No differences in mid-term survival and clinical outcome between CT- and MRI-based patient-specific instrumentation for total knee arthroplasty, a randomized controlled trial

PURPOSE

The purpose of this prospective randomized controlled trial was to compare the clinical outcome and the survival rate of total knee arthroplasty between CT- and MRI-based patient-specific instrumentation 5 years after initial surgery.

METHODS

At a mean follow-up of 5.8 years (SD 0.3), 98 patients (64% women, loss to follow-up 28%) were included in this analysis. To assess the differences in clinical outcome, patients fulfilled PROMs preoperatively and at each follow-up moment. At final follow-up, the Forgotten Joint Score was adjusted.

RESULTS

At final follow-up, no new patients underwent revision surgery in both groups. Regarding the clinical outcome, no statistically significant difference between the groups was found. The Forgotten Joint Score was only performed at final follow-up and showed no significant difference between both groups.

CONCLUSION

At mid-term follow-up, survival rates between CT- and MRI-based patient-specific instrumentation did not show a significant difference. Regarding clinical outcome, only the EQ-5D-VAS (p < 0.040) showed a statistically significant difference over time, in favor of the MRI-group.

LEVEL OF EVIDENCE

Level I.

Cost-effectiveness of patient specific vs conventional instrumentation for total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Over the past years, patient specific instrumentation (PSI) for total knee arthroplasty (TKA) has been implemented and routinely used. No clear answer has been given on its associated cost and cost-effectiveness when compared to conventional instrumentation (CI) for TKA.

AIM

To compare the cost and cost-effectiveness of PSI TKA compared to CI TKA.

METHODS

A literature search was performed in healthcare, economical healthcare, and medical databases (MEDLINE, EMBASE, CINAHL, Web of Science, Cochrane Library, EconLit). It was conducted in April 2021 and again in January 2022. Relevant literature included randomised controlled trials, retrospective studies, prospective studies, observational studies, and case control studies. All studies were assessed on methodological quality. Relevant outcomes included incremental cost-effectiveness ratio, quality-adjusted life years, total costs, imaging costs, production costs, sterilization associated costs, surgery duration costs and readmission rate costs. All eligible studies were assessed for risk of bias. Meta-analysis was performed for outcomes with sufficient data.

RESULTS

Thirty-two studies were included into the systematic review. Two were included in the meta-analysis. 3994 PSI TKAs and 13267 CI TKAs were included in the sample size. The methodological quality of the included studies, based on Consensus on Health Economic Criteria-scores and risk of bias, ranged from average to good. PSI TKA costs less than CI TKA when considering mean operating room time and its associated costs and tray sterilization per patient case. PSI TKA costs more compared to CI TKA when considering imaging and production costs. Considering total costs per patient case, PSI TKA is more expensive in comparison to CI TKA. Meta-analysis comparing total costs for PSI TKA, and CI TKA showed a significant higher cost for PSI TKA.

CONCLUSION

Cost for PSI and CI TKA can differ when considering distinct aspects of their implementation. Total costs per patient case are increased for PSI TKA when compared to CI TKA.

The relation between socioeconomic status and patient symptoms before and one year after lower extremity arthroplasty

Aims

To determine whether there was a relation between socioeconomic status (SES) and patient symptoms before and one year after total knee arthroplasty (TKA), and/or total hip arthroplasty (THA) and whether a change in symptoms was clinically relevant.

Patients and methods

A secondary analysis of a prospective cohort study was conducted on SES and osteoarthritis symptoms of patients (≥45 years old) who received a primary TKA or THA between 2016 and 2018. The relation between SES and respectively pre- and postoperative and change in patient-reported outcome measures including the Oxford Knee Score (OKS), Oxford Hip Score (OHS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), the visual analog scale (VAS) for pain and the EuroQol 5-Dimensions (EQ-5D) were assessed using linear mixed-effects regression models adjusted for age and sex. The following potential confounding variables were considered in the regression models: body mass index (BMI), American Society of Anesthesiologists (ASA)- classification, Charnley-classification, smoking status, and alcohol consumption.

Results

Patients with lower SES were mostly female, had a higher BMI and ASA-classification compared to patients with a higher SES. Patients with lower SES reported lower OKS (β = 3.78, P = 0.001). Patients undergoing THA reported lower scores for the OHS (β = 4.78, P = 0.001), WOMAC (β = 11.7, P = 0.001), and less pain (VAS, β = -0.91, P = 0.001). No statistically significant differences between SES groups were seen in the quality of life and health status as measured with the EQ-5D.

Conclusion

Patients with a lower socioeconomic status reported worse symptoms and showed less clinically relevant improvement at one-year follow-up.

Osteochondral impression fracture of the patella after sports collision injury

This article reports a case of a teenager who suffered a frontal collision sports injury. Computed Tomography (CT) revealed a fracture of the inferior pole of the patella without obvious displacement and retro patellar cortical impression with 5 mm step off. Surgical intervention was performed using β-tricalcium phosphate (β-TCP) and 3.0 cannulated screw fixation.At 3-month follow-up, the wound showed good healing. No pain was observed. The patient was able to flex up to 100° with full extension. There were no signs of hydrops with full stability of the knee.Good postoperative results can be obtained in osteochondral impression fractures of the patella using surgical intervention to elevate the osteochondral fragment, graft it with β-TCP and raft it with 3.0 cannulated screws.

Demographics are no clinically relevant predictors of patient-reported knee osteoarthritis symptoms - Comprehensive multivariate analysis

Aims & objectives

In clinical practice, arthroplasties are predominantly indicated by clinical and radiological assessment of osteoarthritis. Pain and function are individually considered, but a comprehensive analysis of differences in symptom reporting by pre-operative factors is lacking. In the present study, we determined differences in patient reported outcome measures between demographic groups among patients admitted to total knee arthroplasty.

Materials & methods

Between 2010 and 2019, we collected pre-operative Oxford Knee Scores, Western Ontario and McMaster University Osteoarthritis Index, quality of life in 2555 patients undergoing primary, osteoarthritis-indicated total knee arthroplasty at Patients were categorized by sex, age (<70, 70-80, >80 years), body mass index (BMI <25, 25-30, 30-35, >35 kg/m2), American Society of Anesthesiologists -classification (ASA 1, 2, ≥3) and Charnley score (A, B1, B2, C). Symptom scores (median, IQR) were compared using bivariate and multivariate methods.

Results

The cohort was 60% female, 70.0 years old (69.4-70.1), and BMI was 28.9 kg/m2 (29.6-30.0). As compared to bivariate analyses, between-group differences in multivariate analyses were consistently smaller. BMI and sex remain significant predictors after adjustment for age, ASA, and Charnley. Age, ASA, and Charnley were no independent predictors of symptom scores. A group of patients (30%) reported no physical dysfunction, and less symptom severity in pain and stiffness.

Conclusion

This study is the first to show that differences in symptom reporting between demographic groups are partly colinear, and are negligible for prediction of symptoms. Lastly, for a significant proportion of patients, patient-reported outcome measures do not adequately present disease severity.

First clinical results of 1-year follow-up of the femoral neck system for internal fixation of femoral neck fractures

BACKGROUND

Closed reduction and internal fixation (CRIF) is the preferred treatment to retain the native joint and maintain optimal functionality in femoral neck fractures. Sliding hip screw (SHS) and cannulated hip screws (CHS) are established CRIF options. SHS offer high biomechanical stability, whereas CHS are minimally invasive. These established systems have a 17-21% failure rate. The Femoral neck system (FNS) was recently developed to combine the advantages of both predecessors. The aim of this study was to describe the first clinical experience with this novel implant with special emphasis on the safety and efficacy.

METHODS

During a 1-year period all patients in our level-2 trauma centre with a FNF indicated for CRIF were treated using the FNS and evaluated at 2, 6, 12 weeks, 6 months and 1 year postoperatively using patient and fracture characteristics, surgical notes and radiographic imaging.

RESULTS

Thirty-four patients were included, mean age was 63 years (SD 8), 58.2% was female. Fractures were classified as Pauwels I (n = 10), Pauwels II (n = 15), Pauwels III (n = 9), Garden I (n = 1), Garden II (n = 17), Garden III (n = 12) and Garden IV (n = 4). Eight reoperations were reported after 1-year follow-up; osteosyntheses failed in 6 patients due to avascular necrosis (n = 4) and cut-out (n = 2). In two patients the implant was removed due to inexplicable pain. Age (< 65 years) was related to lower risk for failure. There was a trend for females having more failures.

CONCLUSION

This study indicates that the FNS is a potential safe and effective CRIF modality. Age (< 65 years) is an important factor to keep in mind when selecting patients for CRIF as it is related to lower risk for failure. Future long-term follow-up studies with larger populations should indicate if functional results and risk factors for failure are comparable to SHS or CHS.

Orthopaedic surgeons' perspective on the implementation of outpatient hip and knee arthroplasty - Results of a nationwide survey

Background

Outpatient joint arthroplasty (OJA) for the hip and knee is gaining popularity among orthopaedic surgeons worldwide. The purposes of this study were to (1) assess the proportion of Dutch orthopaedic surgeons who perform OJA; (2) identify surgeons' willingness to implement OJA in the future; (3) identify reasons and barriers to implement OJA; and (4) gather surgeon's perspective on the implementation of OJA.

Methods

A 20-item survey was developed and administered by email to orthopaedic surgeons who are a member of the Dutch Hip Society and Dutch Knee Society. Survey response rate was 40% (N = 123).

Results

Twenty-two respondents (18%) already implemented OJA, and 46% of respondents (who don't perform OJA) were interested to implement OJA in the future. Reasons to perform OJA included own positive experiences (82%), available evidence (77%) and patients' request (77%). Proponents' and opponents' view on safety and added value conflicted with each other. Other barriers included patient selection and organizational related (e.g., multidisciplinary support). Surgeons' view on evolution and relevance of OJA significantly differed by respondents who perform OJA versus respondents who don't perform OJA. Most respondents agreed with one another that the healthcare institution benefits most from OJA, and that optimization of the arthroplasty pathway could be reached through better patient education and -participation (e.g., eHealth, wearables).

Conclusion

One in five respondents currently implement OJA pathways, and about half of the remaining respondents are interested to implement OJA in the future. OJA-opponents aren't convinced of the value and safety of OJA, despite accumulating evidence supporting OJA. Future research should inform patient-selection and -acceptance and organizational implementation.

Patient-specific instruments do not show advantage over conventional instruments in unicompartmental knee arthroplasty at 2 year follow-up: a prospective, two-centre, randomised, double-blind, controlled trial

PURPOSE

The aim of this two-centre RCT was to compare pre- and post-operative radiological, clinical and functional outcomes between patient-specific instrumentation (PSI) and conventional instrumented (CI) unicompartmental knee arthroplasty (UKA). It was hypothesised that both alignment methods would have comparable post-operative radiological, clinical and functional outcomes.

METHODS

One hundred and twenty patients were included, and randomly allocated to the PSI or the CI group. Outcome measures were peri-operative outcomes (operation time, length of hospital stay and intra-operative changes of implant size) and post-operative radiological outcomes including the alignment of the tibial and femoral component in the sagittal and frontal plane and the hip-knee-ankle-axis (HKA-axis), rate of adverse events (AEs) and patient-reported outcome measures (PROMs) pre-operatively and at 3, 12 and 24 months post-operatively.

RESULTS

There was a statistically significant difference (p < 0.05) in alignment of the femoral component in the frontal plane in favour of the CI method. No statistically significant differences were found for the peri-operative data or in the functional outcome at 2-year follow-up. In the PSI group, the approved implant size of the femoral component was correct in 98.2% of the cases and the tibial component was correct in 60.7% of the cases. There was a comparable rate of AEs: 5.1% in the CI and 5.4% in the PSI group.

CONCLUSION

The PSI method did not show an advantage over CI in regard of positioning of the components, nor did it show an improvement in clinical or functional outcome. We conclude that the possible advantages of PSI do not outweigh the costs of the MRI scan and the manufacturing of the PSI.

LEVEL OF EVIDENCE

Randomised controlled trial, level I.

Low blood transfusion rate after implementation of tranexamic acid for fast- track hip- and knee arthroplasty. An observational study of 5205 patients

The purpose of this study was to retrospectively evaluate the efficacy of a tranexamic acid (TXA) perioperative protocol for primary hip- and knee arthroplasty, in terms of allogenic blood transfusion rates. A retrospective cohort study was conducted and included all primary hip and knee arthroplasty procedures in the period of 2014-2019. Patients who underwent surgery due to trauma or revision were excluded. A total amount of 5205 patients were eligible for inclusion. Two equal and weight depending doses of TXA were given, preoperative as an oral dose and intravenously at wound closure. The primary outcome was blood transfusion rate. Further analysis on patient characteristics (e.g. age, gender), blood loss, perioperative haemoglobin (Hb) levels and complication/readmission rate was performed. A total of 49 (0.9%) patients received perioperative allogenic blood transfusions. Mean age, distribution of gender, body-mass index, American Society of Anaesthesiologists score, duration of surgery, type of arthroplasty, estimated blood loss, perioperative Hb levels and length of stay were statistically significant different between transfused and not-transfused patients. The incidence of thromboembolic adverse events (e.g. deep vein thrombosis/lung embolism) was 0.5%. Low blood transfusion rate was found after implementation of a standardized perioperative TXA protocol for primary hip and knee arthroplasty.

Management of two-level proximal femoral fractures

We present the case of an 82-year-old female, who experienced a ground-level fall on the trochanter of the right femur. X-rays showed a proximal femoral fracture (PFF) with an unclear and unusual fracture pattern. Three-dimensional CT images were obtained and showed a displaced femoral neck fracture and ipsilateral fracture of the greater trochanter. Our patient underwent unipolar hemiarthroplasty and fixation of the greater trochanter with a hook plate and cable grip. At 11 months, functional outcomes, patient satisfaction and quality of life were excellent. Primary osteoporosis was diagnosed and treatment with bisphosphonates was initiated.Two-level PFFs are rare and complex. Due to ageing and a subsequent increase in osteoporosis, numbers of PFFs with complex fracture patterns might increase in the future. Adequate treatment and early prevention of osteoporosis are key to reduce this risk and lower the overall burden. Surgical treatment should be patient-tailored and focus on minimising the risk of complications and reinterventions.

A short-term radiological and clinical comparison between the bi-cruciate and cruciate retaining total knee arthroplasty A retrospective case controlled study

PURPOSE

The aim of this study was to provide a short term comparison in radiological and clinical outcome between Bi-Cruciate Retaining (BCR)- and Cruciate Retaining (CR) Total Knee Arthroplasty (TKA).

METHODS

The cohort consists of 122 patients undergoing a TKA with PSI, equally distributed over the BCR- and CR-TKA group. Perioperative conditions were observed and radiological images were analysed pre-, 6-weeks, and 1-year postoperative to quantify alignment differences between BCR- and CR-TKA. Preoperatively predicted templates were compared with the implanted size to determine predictive value. In addition mean range of motion and revision rates were determined in both groups.

RESULTS

No significant difference was observed in amount of outliers in component alignment between BCR- and CR-TKA. Outliers of the Hip-Knee-Ankle-Axis (HKA-axis) occurred significantly more frequent (P = 0.009) in the BCR-group (37.7%) compared to CR-TKA (18.0%). No clinically relevant differences regarding the predictive sizing of implant components was obtained. No significant differences were observed in revision rates (P = 1.000) and ROM (p = 0.425) between the BCR-groep and CR-group at 2-years FU.

CONCLUSION

This study illustrates that although the HKA-axis was not fully restored, bi-cruciate retaining surgical technique for BCR-TKA is safe and effective with comparable radiological and clinical outcome as CR TKA. Randomized controlled trials with longer follow up on the HKA-axis alignment and clinical parameters are needed to confirm the presented results and should focus on possible cut off values concerning leg axis in order to define in what patients a BCR-TKA can safely be used.

LEVEL OF EVIDENCE IV

Retrospective Case Controlled Study.

Low blood transfusion rate after implementation of tranexamic acid for fast- track hip- and knee arthroplasty. An observational study of 5205 patients

The purpose of this study was to retrospectively evaluate the efficacy of a tranexamic acid (TXA) perioperative protocol for primary hip- and knee arthroplasty, in terms of allogenic blood transfusion rates. A retrospective cohort study was conducted and included all primary hip and knee arthroplasty procedures in the period of 2014-2019. Patients who underwent surgery due to trauma or revision were excluded. A total amount of 5205 patients were eligible for inclusion. Two equal and weight depending doses of TXA were given, preoperative as an oral dose and intravenously at wound closure. The primary outcome was blood transfusion rate. Further analysis on patient characteristics (e.g. age, gender), blood loss, perioperative haemoglobin (Hb) levels and complication/readmission rate was performed. A total of 49 (0.9%) patients received perioperative allogenic blood transfusions. Mean age, distribution of gender, body-mass index, American Society of Anaesthesiologists score, duration of surgery, type of arthroplasty, estimated blood loss, perioperative Hb levels and length of stay were statistically significant different between transfused and not-transfused patients. The incidence of thromboembolic adverse events (e.g. deep vein thrombosis/lung embolism) was 0.5%. Low blood transfusion rate was found after implementation of a standardized perioperative TXA protocol for primary hip and knee arthroplasty.

CR-lipped bearing is an adequate functional solution to patients with perioperative excessive laxity in cruciate retaining total knee arthroplasty

BACKGROUND

The cruciate retaining lipped (CR-lipped) bearing is designed to provide more anterior-posterior (AP) stability and could be employed to resolve excessive intraoperative laxity during the cruciate retaining TKA (CR-TKA). The aim of the study was to determine whether the CR-lipped bearing in CR-TKAs with a perioperative excessive laxity allows equivalent functional results as compared to the standard CR articulation.

METHODS

A cohort of 111 TKAs with CR-lipped bearings was matched to a cohort of conventional CR bearings regarding age and sex. The CR-lipped bearing was used in patients with excessive knee AP laxity and the regular CR bearing was used in patients without excessive AP laxity during TKA. Various PROMs (WOMAC, KSS, SF-36) were assessed preoperatively and at 5-years postoperative in combination with revision rate and Range of Motion (ROM).

RESULTS

PROMs did not differ significantly between both groups 5-years postoperatively. Mean ROM (flexion) 5-years postoperatively was not significantly different. The implant survivorship was 100% for both cohorts with revision for any reason as end point.

CONCLUSION

Based on these results, the CR-lipped bearing is a safe and effective solution for mild interoperatively assessed PCL laxity during CR-TKA without loss of function or decreased survivorship at 5 years. Peroperative conversion to a PS-TKA in order to obtain satisfactory functional scores might therefore not be necessary when mild PCL laxity is observed during surgery. Further research should focus on verifying this approach and longer follow-up is needed to generate data on long term survivorship.

LEVEL OF EVIDENCE

Level IV therapeutic, retrospective, cohort study.

Reasons for Unsuccessful Same-Day Discharge Following Outpatient Hip and Knee Arthroplasty: 5½ Years' Experience From a Single Institution

BACKGROUND

Outpatient joint arthroplasty (OJA) is considered safe and feasible in selected patients but should be further optimized to improve success rates. The purposes of this study are to (1) identify the main reasons of unsuccessful same-day discharge (SDD) following hip and knee arthroplasty; (2) determine the hospital length of stay (LOS) following unsuccessful SDD; and (3) assess which independent variables are related to specific reasons for unsuccessful SDD.

METHODS

Five hundred twenty-five patients undergoing total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty between 2013 and 2019 were retrospectively identified. SDD to home was planned in all patients. Specific reasons for unsuccessful SDD and LOS were assessed. Bivariate analysis was performed to find differences in independent variables between patients experiencing a specific reason for unsuccessful SDD and control patients.

RESULTS

One hundred ten patients (21%) underwent unsuccessful SDD. The main reason was postoperative reduced motor function and sensory disturbances (33%). The mean LOS in the unsuccessful SDD group was 1.7 days (standard deviation ± 1.0 days). Postoperative transient reduced motor function and sensory disturbances occurred more often in patients undergoing TKA (P < .001).

CONCLUSION

An option for overnight stay should be available when performing outpatient hip and knee arthroplasty. The main reason for unsuccessful SDD in this study was transient postoperative reduced motor function and sensory disturbance, most likely due to intraoperative local infiltration analgesia in TKA. No other studies have found local infiltration analgesia to be an issue preventing SDD.

Predictors of (Un)successful Same-Day Discharge in Selected Patients Following Outpatient Hip and Knee Arthroplasty

BACKGROUND

It is generally accepted that only selected patients are suitable for outpatient joint arthroplasty (OJA); however, no consensus exists on the optimal selection criteria. We believe patients undergoing OJA should undergo risk stratification and mitigation in an attempt to optimize quality and minimize costs.

METHODS

Patient factors of 525 patients who were selected to have primary elective unicompartmental knee arthroplasty (N = 158), total knee arthroplasty (N = 277), or total hip arthroplasty (N = 90) in an outpatient setting were retrospectively reviewed. A complete case multivariable logistic regression analysis of 440 patients was conducted to identify factors that were independently associated with (un)successful same-day discharge (SDD).

RESULTS

One hundred ten patients (21%) were not able to be discharged on the day of surgery. Charnley class B2 was associated with a higher chance of successful SDD (odds ratio [OR], 0.29; 95% confidence interval [CI], 0.12-0.72), whereas female gender (OR, 1.7; 95% CI, 1.0-2.8), total knee arthroplasty (OR, 1.9; 95% CI, 1.1-3.4), and a higher American Society of Anesthesiologists (ASA) physical function score (ASA II: OR, 1.9; 95% CI, 1.1-3.3; ASA III: OR, 3.9; 95% CI, 1.1-13) were associated with a higher risk of unsuccessful SDD.

CONCLUSION

These results in a preselected population suggest the need for further specifying and improving selection criteria for patients undergoing OJA and emphasize the importance of an in-hospital backup plan for patients at risk of unsuccessful SDD. Previous contralateral joint arthroplasty is a protective factor for successful SDD.

Comparable clinical outcome and implant longevity after CT- or MRI-based patient-specific instruments for total knee arthroplasty: a 2-year follow-up of a RCT

PURPOSE

Patient-specific instruments (PSI) are already widespread used in total knee arthroplasty (TKA). Either computed tomography (CT) scans or magnetic resonance imaging (MRI) scans are used pre-operatively to create jigs to guide resection during surgery. This study is a sequel of previous work that showed significantly more radiological outliers for posterior slope when CT-based guides were used. The aim of this study was to assess differences in revision rate and clinical outcome between the two groups at 2-year follow-up.

METHODS

At the 2-year follow-up, 124 patients were analysed in this prospective, randomised single-blind study. A survival analysis with revision of the TKA as endpoint was performed. Patients fulfilled four patient-reported outcome measurements (PROMs). Scores on the questionnaires were compared between both groups at the different follow-up visits.

RESULTS

At final follow-up, there was no significant difference in the survival rates of the CT- and MRI-based PSI surgery. Postoperatively, the PROMs significantly improved within each group compared with the pre-operative values. There were no significant differences for the PROMs between both groups at the 2-years follow-up.

CONCLUSIONS

Although previous results showed more outliers regarding posterior slope for CT-based PSIs, no difference in revision rate or the outcome of PROMs was found at 2-year follow-up. Further research to determine what the influence is of radiological outliers on implant survival and clinical outcomes is necessary.

LEVEL OF EVIDENCE

I.

Comparable level of joint awareness between the bi-cruciate and cruciate retaining total knee arthroplasty with patient-specific instruments: a case-controlled study

PURPOSE

Bi-cruciate-retaining total knee arthroplasty (BCR-TKA) is recognized as an alternative to the cruciate-retaining total knee arthroplasty (CR-TKA) within the pursuit of retrieving the "forgotten artificial knee joint". The aim of this study was to provide a short-term comparison in functional and clinical outcomes between BCR- and CR-TKA.

METHODS

The cohort consisted of 61 BCR-TKA patients, matched with 61 suitable CR-TKA patients, and operated between 2014 and 2016 due to osteoarthritis. Patient-reported outcome measurements were assessed preoperatively and at 3, 12, 24 and 36 months postoperatively. In addition, perioperative conditions were observed and radiological images were analysed pre- and 1 year postoperatively. Effect size for the FJS-12 was calculated at 3-year follow-up to quantify the difference between BCR- and CR-TKA.

RESULTS

Patients reported a significant improved health-related quality of life (p = 0.017) and a non-significant difference in joint awareness at 3-year-follow-up with a moderate effect size (0.4). Operating time in BCR-TKA (1:16, ± 0:16) is significantly longer (p < 0.000) than in CR-TKA (0:50, ± 0:12). Blood loss significantly increased (p = 0.005) in BCR-TKA (246.4 cc, 79.8) compared to CR-TKA (195.5 cc, ± 106.2). Comparable length of hospital stay (n.s.) was observed in BCR-TKA (1.1 days, ± 1.1) and CR-TKA (1.3 days, ± 1.3). Outliers of the hip-knee-ankle axis occurred significantly more frequent (P = 0.015) in the BCR group (37.7%) compared to CR-TKA (18.0%).

CONCLUSION

Joint awareness of the BCR-TKA was not significantly reduced compared to the CR-TKA. However, this study illustrates that bi-cruciate-retaining surgical technique for TKA is a promising step further in the pursuit of reducing joint awareness and retrieving the artificial forgotten total knee. Since a functional ACL increases rotational stability and proprioception, future research should focus on knee kinematics in modern BCR-TKA measured with gait analyses.

LEVEL OF EVIDENCE

IV therapeutic, retrospective, cohort study.

No difference in mid-term survival and clinical outcome between patient-specific and conventional instrumented total knee arthroplasty: a randomized controlled trial

PURPOSE

The purpose of this multicentre prospective randomized controlled trial was to compare the survival rate and clinical outcome in total knee arthroplasty (TKA) after MRI-based patient-specific instruments (PSI) and conventional instruments 5 years after initial surgery.

METHODS

At a mean follow-up of 5.1 years (0.4), 163 patients (90.6%) with a mean age of 71.8 years (8.7) were analysed. A survival analysis with revision of the TKA as endpoint was performed. The Knee Society Score (KSS), evaluations on plain radiographs and patient-reported outcome measures (PROMs) were obtained preoperatively and at each FU.

RESULTS

At final follow-up, one TKA in the PSI- (1.2%) and 3 TKAs in the conventional group (3.8%) had undergone revision surgery (n.s.). No radiological abnormalities were noted at any time point. Postoperatively, the KSS and PROMs significantly improved within each group compared with the preoperative values. There were no clinically relevant differences for the KSS [PSI: 77.4, 9.8 (95% CI 75.0-79.7) vs. conventional: 77.3 10.5 (95% CI 74.9-79.8)] and the PROMs between both groups (n.s.) at 5 years follow-up.

CONCLUSION

There is still a lack of reliable data on the survival of TKA and clinical evidence, when using PSI for TKA. Longer follow-up studies are, therefore, needed.

LEVEL OF EVIDENCE

I.

Cancer league actions against sunbed use for skin cancer prevention

The incidence of non-melanoma and melanoma skin cancer has been rising in Europe. Although the World Health Organization's International Agency for Research on Cancer has since 2009 classified sunbeds as a Group 1 carcinogen, sunbed use, especially by those under the age of 18, continues to be a concern. As the only platform for cancer leagues in Europe, the Association of European Cancer Leagues decided to explore interest and actions by its member leagues at the national level against sunbed use, to share experiences and to provide background information on possible future collective actions at the EU level.

Revision of partial knee to total knee arthroplasty with use of patient-specific instruments results in acceptable femoral rotation

PURPOSE

Patient-specific instruments (PSI) were initially developed for the alignment of both total knee- (TKA) and partial knee arthroplasty (PKA). We hypothesize that CT-based PSI for PKA-to-TKA revision surgery can restore biomechanical limb alignment and prosthetic component positioning in vivo as calculated pre-operatively, resulting in a limited percentages of outliers.

METHODS

An imaging analysis was performed using CT-based 3D measurement methods based on a pre- and post-revision CT scan. Imaging data were gathered on 10 patients who were operated for PKA-to-TKA revision with the use of PSI based on CT imaging. The planned femur and tibia component position in vivo were compared with the pre-revision planned component position. Outliers were defined as deviations >3.0° from pre-revision planned position for the individual implant components. Adjustments (e.g. resection level and implant size) during surgery were recorded.

RESULTS

The HKA axis was restored accurately in all patients with a mean post-operative HKA axis of 178.1° (1.4°). Five femoral (2 varus, 2 internal rotation and 1 extension) and 14 tibial guides (2 varus, 6 anterior slope, 3 internal rotation and 3 external rotation) on a total of 60 outcome measures were identified as outliers. During surgery, an intraoperative tibial resection of 2 mm extra was performed in three patients. In 80 and 70% for, respectively, the femur and tibia, the surgeon-planned size was implanted during surgery. All patient-specific guides fitted well in all patients. No intraoperative or post-operative complications related to surgery were registered.

CONCLUSIONS

This study introduced a unique new concept regarding PSI, PKA-to-TKA revision surgery. Based on the results, we were unable to fully confirm our hypothesis. PSI as a "new" tool for PKA-to-TKA revision surgery appears to be an accurate tool for the alignment of the TKA femur component. The tibial guide seems more susceptible to errors, resulting in a substantial percentage of outliers.

LEVEL OF EVIDENCE

Prospective cohort study, Level II.

Consistency in patient-reported outcome measures after total knee arthroplasty using patient-specific instrumentation: a 5-year follow-up of 200 consecutive cases

PURPOSE

The purpose of this study was to evaluate the 5-year follow-up results of the first 200 total knee arthroplasties (TKA) performed by one high-volume surgeon, using patient-specific information (PSI). To date, there has been no other research into the mid-term follow-up of TKA performed using PSI.

MATERIALS AND METHODS

A total of 184 consecutive patients (200 TKA) were evaluated. Outcome measures included implant survival rate, adverse events, and the following patient-reported outcome measures (PROMs); Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), Pain Visual Analogue Score (VAS) and EuroQol-5D Score (EQ-5D).

RESULTS

Revision surgery was performed for late secondary prosthetic joint infection (n = 1, total revision), aseptic loosening (n = 1, tibial component revision), instability (n = 1, isolated polyethylene insert exchange), and polyethylene insert breakage (n = 1, isolated polyethylene insert exchange). Other adverse events were as follows: debridement, antibiotics and implant retention for early prosthetic joint infection (n = 1), surgical debridement for haemarthrosis (n = 1), superficial wound infection (n = 2), thromboembolic events (n = 2), compartment syndrome (n = 1), and nerve injury (n = 2). All median outcome scores for patient reported outcome measures at 5 years improved significantly compared with the preoperative values (p ≤ 0.05). Median outcome scores were not significantly different between 1- and 5-year moments of follow-up, except for a significant decrease of EQ-VAS (p ≤ 0.05) between these two follow-up moments.

CONCLUSION

PROMs are consistent for 5-year follow-up of TKA using PSI. After 5 years of follow-up, revision surgery for any reason occurred in four patients (2%).

LEVEL OF EVIDENCE

III.

Cementless versus cemented Oxford unicompartmental knee arthroplasty: early results of a non-designer user group

PURPOSE

Although fewer tibial radiolucent lines are observed in cementless Oxford unicompartmental knee arthroplasty (UKA) compared with cemented Oxford UKA, an independent comparative study on this topic is lacking.

METHODS

In this multicentre retrospective study, a cohort of 60 consecutive cases of cementless Oxford UKA is compared with a cohort of 60 consecutive cases of cemented Oxford UKA. Radiolucent lines, survival, perioperative data and clinical results were compared.

RESULTS

No complete tibial radiolucent lines were observed in either group. Seventeen per cent of partial tibial radiolucent lines were observed in the cementless group versus 21 % in the cemented group (n.s.). The percentage of tibial radiolucent zones was 4 versus 9 %, respectively (p = 0.036). Survival rates were 90 % at 34 months for the cementless group and 84 % at 54 months for the cemented group (n.s.). Mean operation time was 10 min shorter in the cementless group (p < 0.001), and clinical results were not significantly different.

CONCLUSIONS

Although no significant differences in radiolucent lines were found between both groups, they appear to be more common in the cemented group. This confirms previous results from reports by prosthesis designers. The presence of radiolucent lines after cemented Oxford UKA does not correlate with clinical outcome or survival.

LEVEL OF EVIDENCE

III.

No difference in clinical outcome between patient-matched positioning guides and conventional instrumented total knee arthroplasty two years post-operatively

Aims

We wished to compare the clinical outcome, as assessed by questionnaires and the rate of complications, in total knee arthroplasty (TKA) undertaken with patient-matched positioning guides (PMPGs) or conventional instruments.

Patients and Methods

A total of 180 patients (74 men, 106 women; mean age 67 years) were included in a multicentre, adequately powered, double-blind, randomised controlled trial. The mean follow-up was 44 months (24 to 57).

Results

There were no significant or clinically relevant differences between the two groups for all outcome measures (Knee Society Score, p = 0.807; Oxford Knee Score, p = 0.304; Western Ontario and McMaster osteoarthritis index, p = 0.753; visual analogue scale for pain, p = 0.227; EuroQol-5D-3L index score, p = 0.610; EuroQol-5D-3L VAS health, p = 0.968.) There was no difference in the rate of complications (p = 0.291).

Conclusion

PMPGs are already in relatively common use and their short-term clinical results are equal to conventional instrumented TKA. Cite this article: Bone Joint J 2016;98-B:939–44.

Patient specific guides for total knee arthroplasty are ready for primetime

AIM: To present the radiological results of total knee arthroplasty (TKA) with use of patient specific matched guides (PSG) from different manufacturer in patients suffering from severe osteoarthritis of the knee joint.

METHODS: This study describes the results of 57 knees operated with 4 different PSG systems and a group operated with conventional instrumentation (n = 60) by a single surgeon. The PSG systems were compared with each other and subdivided into cut- and pin PSG. The biomechanical axis [hip-knee-ankle angle (HKA)], varus/valgus of the femur [frontal femoral component (FFC)] and tibia (frontal tibial component) component, flexion/extension of the femur [flexion/extension of the femur component (LFC)] and posterior slope of the tibia [lateral tibial component (LTC)] component were evaluated on long-leg standing and lateral X-rays. A percentage of > 3^° deviation was seen as an outlier.

RESULTS: The inter class correlation coefficient (ICC) revealed that radiographic measurements between both assessors were reliable (ICC > 0.8). Fisher exact test was used to test differences of proportions. The percentage of outliers of the HKA-axis was comparable between both the PSG and conventional groups (12.28% vs 18.33%, P < 0.424) and the cut- and pin PSG groups (14.3% vs 10.3%, P < 1.00). The percentage of outliers of the FFC (0% vs 18.33%, P < 0.000), LFC (15.78% vs 58.33%, P < 0.000) and LTC (15.78% vs 41.67%, P < 0.033) were significant different in favour of the PSG group. There were no significant differences regarding the outliers between the individual PSG systems and the PSG group subdivided into cut- and pin PSG.

CONCLUSION: PSG for TKA show significant less outliers compared to the conventional technique. These single surgeon results suggest that PSG are ready for primetime.

Inter-observer reliability of measurements performed on digital long-leg standing radiographs and assessment of validity compared to 3D CT-scan

BACKGROUND

Long-leg radiographs (LLR) are often used in orthopaedics to assess limb alignment in patients undergoing total knee arthroplasty (TKA). However, there are still concerns about the adequacy of measurements performed on LLR. We assessed the reliability and validity of measurements on LLR using three-dimensional computed tomography (3D CT)-scan as a gold standard.

METHODS

Six different surgeons measured the mechanical axis and position of the femoral and tibial components individually on 24 LLR. Intraclass correlation coefficients (ICC) were calculated to obtain reliability and Bland-Altman plots were constructed to assess agreement between measurements on LLR and measurements on 3D CT-scan.

RESULTS

ICC agreement for the six observer measurements on LLR was 0.70 for the femoral component and 0.80 for the tibial component. The mean difference between measurements performed on LLR and 3D CT-scan was 0.3° for the femoral component and -1.1° for the tibial component. Variation of the difference between LLR and 3D CT-scan for the femoral component was 1.1° and 0.9° for the tibial component. 95% of the differences between measurements performed on LLR and 3D CT-scan were between -1.9 and 2.4° (femoral component) and between -2.9 and 0.7 (tibial component).

CONCLUSION

Measurements on LLR show moderate to good reliability and, when compared to 3D CT-scan, show good validity.

CLINICAL TRIAL REGISTRATION NUMBER

institutional review board Atrium-Orbis-Zuyd, number: 11-T-15.

LEVEL OF EVIDENCE

Prospective cohort study, Level II.

No radiographic difference between patient-specific guiding and conventional Oxford UKA surgery

PURPOSE

Implant position is an important factor in unicompartmental knee arthroplasty (UKA) surgery. Results on conventional UKA alignment are commonly described in literature. Patient-specific guiding (PSG) is a new technique for positioning the Oxford UKA. Our hypothesis is that PSG improves component position without affecting the HKA angle.

METHODS

This prospective study compares the results of our first thirty cases of cementless Oxford UKA using PSG with thirty cases using conventional outlining. Baseline characteristics for both groups were identical. Details on handling of the guide, estimated blood loss and operation time were recorded. Postoperative screened radiographs and standing long-leg radiographs of both groups were compared.

RESULTS

Median AP position of the femoral component was 3 degrees varus (-5 to 9) using PSG versus 2 degrees varus (-10 to 8) for the conventional group. For the femoral flexion, this was 9 degrees flexion (0-16) using PSG versus 12 degrees flexion (0-20). The tibial median AP position was 1 degree varus (-3 to 7) using PSG versus 2 degrees varus (-5 to 10). The median tibial posterior slope was 5 degrees (1-10) using PSG versus 5 degrees (0-12). All guides aligned well. No conversion to conventional outlining was performed, and no significant changes had to be made to the original approved plan. Operation time, estimated blood loss and postoperative haemoglobin drop were not significantly different between both groups.

DISCUSSION

Implant position was not different between both groups, even in the early phase of the learning curve. Perioperative results were not different between both groups.

LEVEL OF EVIDENCE

III.

Revision from unicompartmental to total knee replacement: the clinical outcome depends on reason for revision

Although it has been suggested that the outcome after revision of a unicondylar knee replacement (UKR) to total knee replacement (TKR) is better when the mechanism of failure is understood, a comparative study on this subject has not been undertaken. A total of 30 patients (30 knees) who underwent revision of their unsatisfactory UKR to TKR were included in the study: 15 patients with unexplained pain comprised group A and 15 patients with a defined cause for pain formed group B. The Oxford knee score (OKS), visual analogue scale for pain (VAS) and patient satisfaction were assessed before revision and at one year after revision, and compared between the groups. The mean OKS improved from 19 (10 to 30) to 25 (11 to 41) in group A and from 23 (11 to 45) to 38 (20 to 48) in group B. The mean VAS improved from 7.7 (5 to 10) to 5.4 (1 to 8) in group A and from 7.4 (2 to 9) to 1.7 (0 to 8) in group B. There was a statistically significant difference between the mean improvements in each group for both OKS (p = 0.022) and VAS (p = 0.002). Subgroup analysis in group A, performed in order to define a patient factor that predicts outcome of revision surgery in patients with unexplained pain, showed no pre-operative differences between both subgroups. These results may be used to inform patients about what to expect from revision surgery, highlighting that revision of UKR to TKR for unexplained pain generally results in a less favourable outcome than revision for a known cause of pain.

Intra-operative results and radiological outcome of conventional and patient-specific surgery in total knee arthroplasty: a multicentre, randomised controlled trial

PURPOSE

This prospective, double-blind, randomised controlled trial was designed to address the following research questions: firstly, is there a significant difference in outliers in alignment in the frontal and sagittal plane between PSG TKA and conventional TKA. Secondly, is there a significant difference in operation time, blood loss and length of hospital stay between the two techniques. We hypothesise that there will be fewer outliers with PSG TKA and that operation time, blood loss and length of hospital stay can be significantly reduced with PSG.

METHODS

A total of 180 patients were randomised for PSG TKA (group 1) or conventional TKA (group 2) in two centres. Patients were stratified per hospital. Alignment of the mechanical axis of the leg and flexion/extension and varus/valgus of the individual prosthesis components were measured on digital, standing, long-leg and standard lateral radiographs by two independent outcome assessors in both centres. Percentages of outliers (>3°) were determined. We compared blood loss, operation time and length of hospital stay.

RESULTS

There was no statistically significant difference in mean mechanical axis or outliers in mechanical axis between groups. No statistically significant difference was found for the alignment of the individual components in the frontal plane nor for the percentages of outliers. There was a statistically significant difference in outliers for the femoral component in the sagittal plane, with a higher percentage of outliers in the group 1 (p = 0.017). No such significant result was found for the tibial component in that plane. All interclass correlation coefficients were good. Blood loss was 100 mL less in group 1 (p < 0.001). Operation time was 5 min shorter in group 1 (p < 0.001). Length of hospital stay was identical with a mean of 3.6 days (p = 0.657).

CONCLUSIONS

The results in terms of obtaining a neutral mechanical axis and a correct position of the prosthesis components did not differ between groups. A small reduction in operation time and blood loss was found with the PSG system. Future research should especially focus on cost-effectiveness analysis and functional outcome of PSG TKA.

LEVEL OF EVIDENCE

I.

Patient-specific guide for revision of medial unicondylar knee arthroplasty to total knee arthroplasty: beneficial first results of a new operating technique performed on 10 patients

BACKGROUND AND PURPOSE

Unicompartmental to total knee arthroplasty revision surgery can be technically demanding. Joint line restoration, rotation, and augmentations can cause difficulties. We describe a new technique in which single-way fitting guides serve to position the knee system cutting blocks.

METHOD

Preoperatively, images of the distal femur and proximal tibia are taken using CT scanning. These images are used to create a patient-specific guide that fits in one single position on the contours of the bone and the prosthesis in situ. The guides are fixed with pins and then removed. The pins determine the position of the cutting blocks. 10 consecutive revisions were performed using this technique.

RESULTS

All guides fitted well. 7 of 10 femoral prostheses were within the desired AP and sagittal angle ± 3°. However, 1 proximal tibia did not have enough bone stock on the medial plateau for adequate fixation of the guide, so conversion to intramedular referencing was performed. This was to be expected after the preoperative planning. All tibial components were within the desired AP angle ± 3° and 7 of 10 were within the desired sagittal angle. Hip-knee-ankle angle was within 0 ± 3° in 8 of 10 cases.

INTERPRETATION

This new technique makes preoperative planning and execution of this plan during surgery less demanding. Problems such as the need for augmentations can be predicted at the preoperative planning. The instrumentation must be redesigned in order to make this technique work in cases where there is minimal bone stock present.

Preliminary experience with the patient-specific templating total knee arthroplasty

BACKGROUND AND PURPOSE

Patient-specific templating total knee arthroplasty (TKA) is a new method for alignment of a total knee arthroplasty that uses disposable guides. We present the results of the first 40 consecutive patients who were operated on using this technique.

METHODS

In this case-control study, we compared blood loss, operation time, and alignment of 40 TKAs performed using a patient-specific templating alignment technique with values from a matched control group of patients who were operated on by conventional intramedullary alignment technique. Alignment of the mechanical axis of the leg and flexion/extension and varus/valgus of the individual prosthesis components were measured on standing, long-leg, and standard lateral digital radiographs. The fraction of outliers (> 3˚) was determined.

RESULTS

Mean mechanical axis of templating TKAs was 181° with a fraction of outliers of 0.3, and mean mechanical axis of conventional TKAs was 179˚ (outlier fraction 0.5). Fraction of outliers in the frontal plane for femoral components was 0.05 in the templating TKAs and 0.4 in the conventional TKAs, and for tibial components the corresponding values were 0.2 and 0.2. In the templating TKAs and conventional TKAs, fraction of outliers in the sagittal plane was 0.4 and 0.9, respectively, for femoral components and 0.4 and 0.6 for tibial components. Mean operation time was 10 min shorter and blood loss was 60 mL less for templating TKA than for intramedullary-aligned TKAs.

INTERPRETATION

Patient-specific templating TKA showed improved accuracy of alignment and a small reduction in blood loss and operating time compared to intramedullary-aligned TKA, but the fraction of outliers was relatively high. Larger RCTs are needed for further evaluation of the technique and to define the future role of patient-specific template alignment techniques for TKA.