The minimal important change is not a universal fixed value across diagnoses when using the FAOS and FAAM in patients undergoing elective foot and ankle surgery.

PURPOSE: This study aimed to calculate region and diagnosis-specific minimal important changes (MICs) of the Foot and Ankle Outcome Score (FAOS) and the Foot and Ankle Ability Measure (FAAM) in patients requiring foot and ankle surgery and to assess their variability across different foot and ankle diagnoses. METHODS: The study used routinely collected data from patients undergoing elective foot and ankle surgery. Patients had been invited to complete the FAOS and FAAM preoperatively and at 3-6 months after surgery, along with two anchor questions encompassing change in pain and daily function. Patients were categorised according to region of pathology and subsequent diagnoses. MICs were calculated using predictive modelling (MICPRED) and receiver operating characteristic curve (MICROC) method and evaluated according to strict credibility criteria. RESULTS: Substantial variability of the MICs between forefoot and ankle/hindfoot region was observed, as well as among specific foot and ankle diagnoses, with MICPRED and MICROC values ranging from 7.8 to 25.5 points and 9.4 to 27.8, respectively. Despite differences between MICROC and MICPRED estimates, both calculation methods exhibited largely consistent patterns of variation across subgroups, with forefoot conditions systematically showing smaller MICs than ankle/hindfoot conditions. Most MICs demonstrated high credibility; however, the majority of the MICs for the FAOS symptoms subscale and forefoot conditions exhibited insufficient or low credibility. CONCLUSION: The MICs of the FAOS and FAAM vary across foot and ankle diagnoses in patients undergoing elective foot and ankle surgery and should not be used as a universal fixed value, but recognised as contextual parameters. This can help clinicians and researchers in more accurate interpretation of the FAOS and FAAM change scores. LEVEL OF EVIDENCE: Level IV.

The Diagnostic Characteristic and Reproducibility of Bone Scintigraphy Single-Photon Emission Computed Tomography/Computed Tomography for Diagnosing Aseptic Loosening of Uncemented Total Knee Arthroplasty.

BACKGROUND: The primary objective of this study was to investigate the diagnostic characteristics of bone scintigraphy single-photon emission computed tomography/computed tomography (BS-SPECT/CT) for diagnosing aseptic loosening after uncemented total knee arthroplasty (TKA), and to evaluate the following aspects: how to manage inconclusive results, the interobserver reliability, and the location of tracer uptake between symptomatic cases with and without aseptic loosening. METHODS: In this study, 180 patients who had uncemented TKA and persistent knee pain suspected of aseptic loosening were included. As part of routine medical care, BS-SPECT/CT was used, and its results were compared with the reference standard, which involved revision surgery for aseptic loosening or a 12-month follow-up without revision or imaging. Inconclusive BS-SPECT/CT results were considered either negative (best-case scenario) or positive (worst-case scenario). Sensitivity, specificity, positive/negative likelihood ratios (LRs), and positive/negative predictive values (PPV and NPV) were calculated. Sensitivity analyses were conducted by comparing the diagnostic characteristics between cases with a follow-up of less and more than 2 years of follow-up. The anatomical distribution of tracer uptake and interobserver reliability were also evaluated. RESULTS: Of the 180 BS-SPECT/CT scans conducted, 22 were determined positive, 113 negative, and 45 inconclusive. The best-case scenario showed a sensitivity of 66.7%, specificity of 93.8%, +LR 10.8, -LR 0.4, PPV 54.6%, and NPV 96.2%. In contrast, the worst-case scenario had a sensitivity of 94.4%, specificity of 69.1%, +LR 3.1, -LR 0.1, PPV 25.4%, and NPV 99.1%. Sensitivity analyses revealed no relevant differences in characteristics between the 2 TKA-interval groups. The interobserver reliability was fair-to-moderate (κ = 0.39; 95% confidence interval 0.18 to 0.60), with an estimated agreement of 79% (95% confidence interval 70 to 87). Four prosthetic zones had a notably higher proportion of cases with tracer uptake in those with aseptic loosening compared to those without. CONCLUSIONS: The test characteristics of BS-SPECT/CT were deemed appropriate in patients who have complaints of uncemented TKA suspected of aseptic loosening. Inconclusive cases were best categorized as negative, especially in patients who have a short interval between TKA and the first BS-SPECT/CT. Increased tracer uptake in 4 prosthetic zones was observed in cases of aseptic loosening, although interobserver reliability was fair to moderate. LEVEL OF EVIDENCE: Level III, Diagnostic Retrospective Cohort Study.

Total Knee Arthroplasty in the Post-Traumatic Knee: Revision Risks and Functional Outcomes Compared to Osteoarthritic Knees. A Report of Primary Procedures From the Dutch Arthroplasty Register.

BACKGROUND: Total knee arthroplasty (TKA) for post-traumatic arthritis (PTA) poses higher challenges and increased risks of complications compared to TKA for osteoarthritis (OA). This study aimed to compare implant survivorships, reasons for revision, and patient-reported outcome measures between OA and PTA as indications for TKA. METHODS: We selected all primary TKAs for PTA or OA between 2007 and 2020 from the Dutch Arthroplasty Register (Landelijke Registratie Orthopedische Interventies). The study included 3,897 TKA procedures for PTA (median follow-up 4.6 years; interquartile range: 2.2, 7.3) and 255,259 procedures for OA (median follow-up 4.7 years; interquartile range 2.2, 7.6). A total of 10,480 revision procedures were performed across both groups (238 in PTA knees; 10,242 in OA knees). We analyzed the prevalence of preoperative comorbidities and postoperative complications, as well as the reasons for revision, and calculated the implant survival rates. RESULTS: The survival revision rate in the OA group was significantly lower at both follow-up moments (5- and 10- years). The likelihood for revision was increased in TKA for PTA compared to TKA for OA (hazards ratio: 1.16 [95% confidence interval 1.02 to 1.33], P = .03). The most common reason for a revision was instability and arthrofibrosis in the PTA group compared to patellar pain for the OA group. CONCLUSION: This study demonstrated an increased risk for revision for any reason in TKA for PTA compared to OA. Revision for instability and arthrofibrosis were more prevalent in the PTA group, while revision for patellar pain was less prevalent compared to TKA for OA.

Increased risk of aseptic loosening for posterior stabilized compared with posterior cruciate-retaining uncemented total knee replacements: a cohort study of 13,667 knees from the Dutch Arthroplasty Registry.

BACKGROUND AND PURPOSE: While registry studies have suggested a higher risk of revision for posterior-stabilized (PS) compared with posterior cruciate-retaining (CR) total knee replacements (TKR) using cement, it is unknown whether this is also the case for uncemented TKR. We aimed to compare the revision rates of PS and CR designs in patients receiving primary uncemented TKR. PATIENTS AND METHODS: Data from the Dutch arthroplasty register (LROI) was analyzed, comprising 12,226 uncemented primary CR TKRs and 750 uncemented PS TKRs registered between 2007 and 2022. Competing risk and multivariable Cox regression analyses were used to compare revision rates, risks of revision, and reasons for revision between groups. Sensitivity analyses were performed to analyze the risk, concerning the 5 most commonly used implants and performing hospitals for each group. RESULTS: Uncemented PS TKRs had higher 10-year revision rates for any reason and aseptic loosening (6.5%, 95% confidence interval [CI] 4.6-9.2 and 3.9%, CI 2.6-6.7) compared with uncemented CR TKRs (4.2%, CI 3.8-4.7 and 1.4%, CI 1.2-1.7). PS TKRs were 1.4 and 2.5 times more likely to be revised for any reason and aseptic loosening, respectively. These results remained consistent after adjustment for age, sex, BMI, previous surgeries, bearing mobility, and surface modification, with sensitivity analyses. CONCLUSION: We found that uncemented PS implants have a higher rate of revision than uncemented CR implants, mainly due to a higher risk of aseptic loosening.

Association Between Surface Modifications for Biologic Fixation and Aseptic Loosening of Uncemented Total Knee Arthroplasties.

BACKGROUND: Various surface modifications are used in uncemented total knee arthroplasties (TKAs) to enhance bony ingrowth and longevity of implants. This study aimed to identify which surface modifications are used, whether they are associated with different revision rates for aseptic loosening, and which are underperforming compared to cemented implants. METHODS: Data on all cemented and uncemented TKAs used between 2007 and 2021 were obtained from the Dutch Arthroplasty Register. Uncemented TKAs were divided into groups based on their surface modifications. Revision rates for aseptic loosening and major revisions were compared between groups. Kaplan-Meier, Competing-Risk, Log-rank tests, and Cox regression analyses were used. In total, 235,500 cemented and 10,749 uncemented primary TKAs were included. The different uncemented TKA groups included the following: 1,140 porous-hydroxyapatite (HA); 8,450 Porous-uncoated; 702 Grit-blasted-uncoated; and 172 Grit-blasted-Titanium-nitride (TiN) implants. RESULTS: The 10-year revision rates for aseptic loosening and major revision of the cemented TKAs were 1.3 and 3.1%, and for uncemented TKAs 0.2 and 2.3% (porous-HA), 1.3 and 2.9% (porous-uncoated), 2.8 and 4.0% (grit-blasted-uncoated), and 7.9% and 17.4% (grit-blasted-TiN), respectively. Both type of revision rates varied significantly between the uncemented groups (log-rank tests, P < .001, P < .001). All grit-blasted implants had a significantly higher risk of aseptic loosening (P < .01), and porous-uncoated implants had a significantly lower risk of aseptic loosening than cemented implants (P = .03) after 10 years. CONCLUSION: There were 4 main uncemented surface modifications identified, with different revision rates for aseptic loosening. Implants with porous-HA and porous-uncoated had the best revision rates, at least equal to cemented TKAs. Grit-blasted implants with and without TiN underperformed, possibly due to the interaction of other factors.

Compliance to perioperative anticoagulation protocols in elderly patients undergoing elective orthopedic procedures: a retrospective observational cohort study on 548 patients.

BACKGROUND: Compliance with perioperative anticoagulation guidelines is essential to minimize bleeding and thromboembolic risks in patients undergoing surgery. Compared to vitamin-K antagonists (VKAs), perioperative management of direct oral anticoagulants (DOACs) contains fewer steps. Therefore, we hypothesized that noncompliance with guidelines in VKA users is higher than in DOAC users. The primary aim of our study was to investigate the difference in noncompliance to perioperative anticoagulant management guidelines between elderly patients using VKAs versus those using DOACs. The secondary aim was to determine the difference in occurrence of conflicting information communicated to the patients and the difference in incidence of coagulation-related adverse events. METHODS: This retrospective non-controlled observational cohort study examined elderly patients undergoing elective orthopedic surgery in a teaching hospital in the Netherlands. All patients undergoing elective orthopedic surgery between 1 May 2016 and 1 January 2020, aged 70 years and over, using VKAs or DOACs were selected. Nonelective surgeries were excluded. The primary outcome was the noncompliance to perioperative anticoagulant management guidelines. Secondary outcomes were missing or conflicting information on anticoagulation management communicated to the patient and coagulation-related adverse events. For continuous data, the unpaired T-test was used and for categorical data, the chi-square test. RESULTS: In patients using VKAs, noncompliance to one of the steps of perioperative anticoagulation management was 81%, compared to 55% in patients using DOACs (p < 0.001). In most cases, VKAs or DOACs were interrupted for longer than recommended. In 13% of patients using a VKA with perioperative bridging, bridging was not conducted as recommended in the guidelines. In 13% of patients using a DOAC, a low-molecular-weight heparin (LMWH) was prescribed while a DOAC had already been restarted postoperatively. VKA users received conflicting information about perioperative anticoagulation management more often than DOAC users (33% versus 20%; p < 0.001). No difference was seen in postoperative coagulation-related complications. CONCLUSION: Guidelines compliance in DOAC users is higher than in VKA users. Clinical decision support to help in selecting the right interruption interval in DOAC users, simplified standardized perioperative management, good coordination of instructions given to patients, and familiarity with updated guidelines are important in reducing noncompliance.

A scoping review of operative and non-invasive management in the treatment of non-unions.

INTRODUCTION: Non-union occurs when a fracture fails to adequately heal, and requires additional intervention to achieve union. The purpose of this scoping review is to provide a high-level overview of the existing non-union management literature. This review aims to highlight the current literature on non-union management, as well as identify key areas that require future research to provide a better understanding of potential non-union management strategies. METHODS: This study utilized the scoping review framework from Arksey and O'Malley All relevant literature on non-union management was systematically searched for within the OVID Medline, OVID Embase, and Web of Science databases. As a scoping review, this study aimed to identify the high-level trends in non-union literature. This was assessed through a visual and numerical summary of the general themes in non-union literature, as well as the timeline in which these trends have occurred. RESULTS: The literature search identified 8081 articles, of which 2210 articles were included. There is a large body of evidence for various surgical treatment options for non-union. The literature suggests healing rates between 80 and 100 percent for commonly utilized surgical procedures, such as plating with bone graft for long bones. Despite these beneficial healing rates, the requirement of a surgery creates a large socioeconomic burden. The possibility for bone growth stimulator (BGS) options to achieve non-union healing rates in a similar realm as surgical options suggests that the use of a BGS may be a beneficial option prior to surgical intervention, as this would potentially reduce the number of patients who would otherwise require surgery. CONCLUSION: A large body of evidence exists on non-union management, which is largely comprised of case series and reports. The most commonly assessed non-unions include the tibia, wrist, and femur. Bone grafting, plating, and nailing are the most investigated treatment options. BGS are a non-operative treatment options for non-union that provide similar healing rates to surgical options in certain indications within initial observational data. BGS are a potential option for non-operative management of non-unions to reduce socioeconomic burdens of surgical intervention, with a need for further high-quality investigation in this therapeutic area.

Effectiveness of Different Antimicrobial Strategies for Staphylococcal Prosthetic Joint Infection: Results From a Large Prospective Registry-Based Cohort Study.

Background: Treatment of staphylococcal prosthetic joint infection (PJI) usually consists of surgical debridement and prolonged rifampicin combination therapy. Tailored antimicrobial treatment alternatives are needed due to frequent side effects and drug-drug interactions with rifampicin combination therapy. We aimed to assess the effectiveness of several alternative antibiotic strategies in patients with staphylococcal PJI. Methods: In this prospective, multicenter registry-based study, all consecutive patients with a staphylococcal PJI, treated with debridement, antibiotics and implant retention (DAIR) or 1-stage revision surgery between January 1, 2015 and November 3, 2020, were included. Patients were treated with a long-term rifampicin combination strategy (in 2 centers) or a short-term rifampicin combination strategy (in 3 centers). Antimicrobial treatment strategies in these centers were defined before the start of the registry. Patients were stratified in different groups, depending on the used antimicrobial strategy. Cox proportional hazards models were used to compare outcome between the groups. Results: Two hundred patients were included and stratified in 1 long-term rifampicin group (traditional rifampicin combination therapy) or 1 of 3 short-term rifampicin groups (clindamycin or flucloxacillin or vancomycin monotherapy, including rifampicin for only 5 postoperative days). Adjusted hazard ratios (aHRs) for failure in patients treated with short-term rifampicin and either flucloxacillin or clindamycin were almost equal to patients treated with long-term rifampicin combination therapy (aHR = 1.21; 95% confidence interval, .34-4.40). Conclusions: A short-term rifampicin strategy with either clindamycin or flucloxacillin and only 5 days of rifampicin was found to be as effective as traditional long-term rifampicin combination therapy. A randomized controlled trial is needed to further address efficacy and safety of alternative treatment strategies for staphylococcal PJI.

A Pseudoaneurysm of the Inferior Lateral Geniculate Artery Following Total Knee Arthroplasty.

Vascular complications after total knee arthroplasty are rare. We present a case of an inferior lateral geniculate artery pseudoaneurysm which became symptomatic 10 days after total knee arthroplasty in a patient with a cardiac comorbidity and using dabigatran. The pseudoaneurysm was most likely caused by iatrogenic injury during surgery. Fourteen days after the index surgery, the patient was seen with a painful but normal post-total knee arthroplasty effused knee, with a maximum flexion angle of 80 degrees. No signs of infection, hemarthrosis, or neurovascular deficit were present. Radiographic imaging included ultrasonography and computed tomography angiography. The pseudoaneurysm was successfully treated with coil embolization. The etiology, presentation, diagnosis, and treatment of a geniculate artery pseudoaneurysm are discussed in this case report.

Long-Term Clinical Performance of an Uncemented, Mobile Bearing, Anterior Stabilized Knee System and the Impact of Previous Knee Surgery.

BACKGROUND: The aim of this study is to report long-term survival and patient-reported outcome measures (PROMs) of the uncemented low contact stress total knee system and explore the potential association between prior knee surgery and outcomes. METHODS: A total of 1,289 procedures in 1,068 patients performed between 2000 and 2010 (mean follow-up 11.1 years) were retrospectively identified. All patients received an uncemented, mobile bearing, anterior stabilized (cruciate sacrificing) knee implant with a porous coating on the bone-prosthesis surface. Implant survival was calculated using competing risk analyses at 5, 10, and 15 years. PROMs include the Oxford Knee Score, Knee Society Score (domain function), EuroQol 5D-3L, and Numeric Rating Scale for pain during rest and activity, and for overall satisfaction. The association between previous surgery (no surgery versus meniscectomy versus arthroscopy versus corrective osteotomies) and implant survival was assessed with multivariable Cox proportional hazards analysis; the association with PROMs was assessed with multivariable linear regression analyses. RESULTS: Survival after 5, 10, and 15 years was 97.0% (95% CI 96.0-98.0), 96.3% (95% CI 95.3-97.3), and 96.0% (95% CI 94.8-97.2), respectively. The most common reason for revision was aseptic loosening of the tibial tray (23/49 revisions, 47%). All PROMs were comparable with the reference values of the Dutch Arthroplasty Register. History of knee surgery prior to TKA was not associated with survival or PROMs. CONCLUSION: The low contact stress uncemented mobile bearing knee implant provides excellent survival and patient satisfaction in our cohort. Previous surgery does not seem to compromise results in our population.

Eighteen-Year Outcome of an Uncemented "Meniscal Bearing", Cruciate-Retaining Total Knee System.

BACKGROUND: The aim of this study is to evaluate the survival, radiographic, and functional outcomes of the uncemented "meniscal bearing" cruciate-retaining Low Contact Stress (LCS) (DePuy Synthes, Warsaw, IN, USA) total knee system after a long-term follow-up period. METHODS: A total of 56 patients (67 knees) who received an uncemented "meniscal bearing" cruciate-retaining LCS total knee system between 2000 and 2005 were retrospectively reviewed. Patients were 64 ± 7 years old with osteoarthritis as the indication for arthroplasty. The survivorship, radiographs, and patient-reported outcome measures (PROMs) were analyzed. RESULTS: The all-cause survival after 5, 10, 15, and 18 years was 97.0%, 93.8%, 92.0%, and 92.0%, respectively. Survival with revision for aseptic loosening as an end point was 98.4% at 5 years and 96.7% at 10, 15, and 18 years. Reasons of revisions and their interventions consisted of anterior knee pain requiring secondary patellar resurfacing (n = 3, 60%), polyethylene wear requiring an insert exchange (n = 2, 40%), and bearing spin-out requiring an insert exchange (n = 1, 20%). Two of the 5 revision cases developed aseptic loosening of the tibial component later on during the study period. A radiographic analysis demonstrated radiolucent lines in 14/47 implants (30%) after 12.0 ± 3.8 years, but were not revised, respectively. After a mean follow-up of 18.5 years, PROMs (n = 20) were found comparable with the 1-year postoperative PROMs of all implants reported by the LROI (Dutch Arthroplasty Register). CONCLUSION: This present study demonstrates good results of the uncemented "meniscal bearing" cruciate-retaining LCS total knee system toward survival and functional outcomes after a long-term median follow-up of 17.5 years. LEVEL OF EVIDENCE: Therapeutic retrospective cohort study, LEVEL III.

No common peroneal nerve palsies found after a peroneal nerve release prior to TKA in fixed valgus deformities (a retrospective cohort study).

PURPOSE: The main purpose of this study was to analyse the incidence of Common Peroneal Nerve Palsy (CPNP) after Total Knee Arthroplasty (TKA) for all alignments. Secondarily, the efficiency and safety of a Peroneal Nerve Release (PNR) prior to TKA in preoperative severe fixed valgus deformities were evaluated to prevent a CPNP. METHODS: Overall, 7612 TKAs were performed in the institution from 2009 to 2021. 1913 TKAs were performed by three surgeons, who consistently performed a PNR in case of a fixed valgus deformity of (1) more than 15°, or (2) more than 10° but in combination with a flexion contracture of more than 15°. Patients with fixed valgus deformities of more than 10° were identified (81 knees) and a comparison was made between the patients who received a PNR (26 knees) and those who did not receive a PNR (55 knees). Data for the analysis were collected from patient medical files and were compared with the Chi2-test or Fisher Exact test. RESULTS: A CPNP incidence of 0.2% (16/7612) was found after TKA for all alignments together. No CPNP cases (0%) were developed in the PNR-group, compared to five (9%) in the non-PNR group (p = NS). A larger preoperative valgus angle (17° vs 13°, p < 0.001) and flexion contracture (10° vs 3°, p < 0.001) was present in the PNR group compared with the non-PNR group. No PNR-related complications were reported. CONCLUSION: The CPNP incidence in this study is consistent with the previous literature. Furthermore, although not significant, the group that received a PNR procedure developed fewer CPNPs compared to the group without PNR. LEVEL OF EVIDENCE: Retrospective cohort study, III.

Design and rationale of the ATtune Knee Outcome Study (ATKOS): multicenter prospective evaluation of a novel uncemented rotating platform knee system.

BACKGROUND: Total Knee Arthroplasty (TKA) remains the gold standard for treatment of debilitating symptoms of knee osteoarthritis (OA). Even though providing satisfactory results for the majority of patients, some studies report dissatisfaction after TKA to be as high as 20%. Among other things, pain catastrophising and self-efficacy are thought to compromise results of TKA. Implant manufacturers keep improving upon their designs in an attempt to improve functional outcomes. One of these novel knee systems is the Attune. To our knowledge, there are no clinical follow-up studies reporting results of the uncemented version. The main objective of this multicentre prospective observational study is to evaluate revision rate, complications, radiographic outcomes (i.e. alignment and radiolucent lines) and patient reported outcomes of the uncemented Attune mobile bearing TKA. Secondary objectives are (1) to assess physical function, return to sport and return to work after TKA and (2) to evaluate the long-term effect of preoperative psychological factors on satisfaction after TKA. METHODS: All patients presenting in the participating centres with knee pathology warranting joint replacement therapy will be considered for inclusion, an absolute indication for cemented fixation is the only exclusion criterium. Evaluation of clinical and radiographic performance (e.g. radiolucent lines) is done at 6 weeks, 6 months, 1 year, 5 years and 10 years after surgery using validated patient reported outcome measures. Cumulative revision rates are calculated after 5 and 10 years using Kaplan-Meier methods. Physical function is assessed with performance based measurements before and 1 year after surgery. Return to sports is assessed using the Tegner and University of California Los Angeles (UCLA) activity rating scale before and 1 year after surgery. Return to work is evaluated by inviting patients of working age to complete a short questionnaire 1 year after surgery. Psychologic factors are assessed using questionnaires for pain catastrophising, pain self-efficacy and mental health before, 5 years and 10 years after surgery. Preoperative psychologic scores are correlated to functional outcomes. DISCUSSION: The current study aims to report the clinical performance of a novel implant and can help provide insight in factors that play a role in satisfaction after TKA. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04247672 (January 30, 2020).

Risk of revision for medial unicompartmental knee arthroplasty according to fixation and bearing type : short- to mid-term results from the Dutch Arthroplasty Register.

AIMS: Uncemented mobile bearing designs in medial unicompartmental knee arthroplasty (UKA) have seen an increase over the last decade. However, there are a lack of large-scale studies comparing survivorship of these specific designs to commonly used cemented mobile and fixed bearing designs. The aim of this study was to evaluate the survivorship of these designs. METHODS: A total of 21,610 medial UKAs from 2007 to 2018 were selected from the Dutch Arthroplasty Register. Multivariate Cox regression analyses were used to compare uncemented mobile bearings with cemented mobile and fixed bearings. Adjustments were made for patient and surgical factors, with their interactions being considered. Reasons and type of revision in the first two years after surgery were assessed. RESULTS: In hospitals performing less than 100 cases per year, cemented mobile bearings reported comparable adjusted risks of revision as uncemented mobile bearings. However, in hospitals performing more than 100 cases per year, the adjusted risk of revision was higher for cemented mobile bearings compared to uncemented mobile bearings (hazard ratio 1.78 (95% confidence interval 1.34 to 2.35)). The adjusted risk of revision between cemented fixed bearing and uncemented mobile bearing was comparable, independent of annual hospital volume. In addition, 12.3% of uncemented mobile bearing, 20.3% of cemented mobile bearing, and 41.5% of uncemented fixed bearing revisions were for tibial component loosening. The figures for instability were 23.6%, 14.5% and 11.7%, respectively, and for periprosthetic fractures were 10.0%, 2.8%, and 3.5%. Bearing exchange was the type of revision in 40% of uncemented mobile bearing, 24.3% of cemented mobile bearing, and 5.3% cemented fixed bearing revisions. CONCLUSION: The findings of this study demonstrated improved survival with use of uncemented compared to cemented mobile bearings in medial UKA, only in those hospitals performing more than 100 cases per year. Cemented fixed bearings reported comparable survival results as uncemented mobile bearings, regardless of the annual hospital volume. The high rates of instability, periprosthetic fractures, and bearing exchange in uncemented mobile bearings emphasize the need for further research. Cite this article: Bone Joint J 2021;103-B(7):1261-1269.

Evaluation of the 'Spaarne soft tissue procedure' as a treatment for recurrent patellar dislocations: a four-in-one technique.

PURPOSE: The 'Spaarne soft tissue procedure', is a 4-in-1 soft tissue procedure that treats recurrent patellar dislocations in the young and active population. The procedure has not yet described elsewhere. The purpose of this study is to analyse the redislocation rate and to evaluate the postoperative knee function and patient satisfaction. METHODS: Twenty-seven patients (34 knees) underwent the four-in-one SST-procedure. The 4-step technique required a minor change in 2010, including the use of a smaller strip of the patellar tendon for transposition. After a median follow-up of 10.4 years, the redislocation rate was evaluated as the primary outcome measure. Secondary outcome measures were functional outcome (IKDC, Kujala, Lysholm and Tegner activity scale) and Numeric Rating Scales for satisfaction and pain. RESULTS: Redislocation occurred in 8 cases (23.5%) and subluxation occurred in 13 cases (38.2%) post-surgery. A significant higher number of redislocations and subluxations were seen before 2010 (p = 0.04, p = 0.03). The median postoperative IKDC, Lysholm and Kujala scores for the total group were 54, 76 and 81 respectively. Pre- and postoperative Tegner activity scale were both level 3. Median NRS scores during rest, walking and sports were 1, 3 and 5 respectively. Satisfaction with the procedure was reported as 'excellent' or 'good' by 79% of the patients. CONCLUSION: Despite the high overall redislocation rate and increased pain scores, the SST-procedure shows to be a safe procedure in patients with recurrent patellar dislocations based on the cases after 2010. Mid- and long-term results show moderate to good functional outcomes and satisfaction. LEVEL OF EVIDENCE: Therapeutic retrospective cohort study, LEVEL III.

Bilateral massive osteolysis of uncertain origin after total knee arthroplasty: A case report and review of literature.

INTRODUCTION AND IMPORTANCE: Periprosthetic osteolysis (PPOL) is a common complication after total knee arthroplasty (TKA) and is most commonly caused by wear-induced particles. CASE PRESENTATION: We report an unusual case of massive bilateral PPOL in the posterior flanges of the femur and patellae 4 years after bilateral uncemented TKA without patellar resurfacing in a 71-year old female. Bilateral staged revision surgery including polyethylene exchange and allograft morselized bone impaction was performed to treat the osteolytic lesions. There were no signs of implant malalignment, polyethylene wear or component loosening. CLINICAL DISCUSSION: Several factors are associated with an increased risk on PPOL (e.g. polyethylene sterilization method, patient age, male gender). Surgical intervention in the context of massive PPOL should include replacement of a potential particle generator (most often polyethylene), correction of potential malalignment, treatment of bone defects and assessment of implant anchorage. CONCLUSION: This report highlights the available evidence on clinical presentation, associated risk factors and preferred treatment strategy of massive osteolytic lesions after TKA according to available evidence.

No clinical difference between TiN-coated versus uncoated cementless CoCrMo mobile-bearing total knee arthroplasty; 10-year follow-up of a randomized controlled trial.

PURPOSE: Improvement of biomechanical properties of cobalt-chromium-molybdenum (CoCrMo) implant surface and reduction of adhesive wear is achieved by titanium-nitride (TiN) coating in vitro. Less pain, higher postoperative outcome scores and a lower revision rate after TKA with a TiN-coated CoCrMo TKA compared with uncoated CoCrMo TKA after 10-year follow-up was hypothesized. METHODS: In a double-blinded RCT, 101 patients received a cementless mobile-bearing CoCrMo TKA, either TiN-coated or uncoated. The primary outcome measure was the visual analogue scale (VAS) score for pain and secondary outcome measures were the Knee Society Score (KSS), Oxford Knee Score (OKS), revision rate and adverse events. Patients were assessed at 6 weeks, 6 months, 1 year, 5 years and 10 years, postoperatively. RESULTS: 68 patients (67%) were available for 10-year follow-up. No difference was found in any of the assessed outcome measures with a mean decrease in VAS score (31.6 ± 22.9) and a mean increase in OKS (10.9 ± 8.4), KSS (29.3 ± 31.4), KSSK (26.4 ± 18.2) and KSSF (4.1 ± 22.9). Overall revision rate was 7% (coated 6% vs uncoated 8%) without additional revision procedures between 5 and 10-year follow-up. CONCLUSIONS: The in vitro potential benefits of TiN coating did not result in better clinical outcome when compared to an uncoated cementless TKA. Pain, functional outcome and revision rates were comparable after 10-year follow-up. TiN-coated cementless TKA provides comparable good long-term results, similar to uncoated cementless CoCrMo TKA. LEVEL OF EVIDENCE: Level 1, Therapeutic Study NETHERLANDS TRIAL REGISTER: NL2887/NTR3033.

What Are the Frequency, Related Mortality, and Factors Associated with Bone Cement Implantation Syndrome in Arthroplasty Surgery?

BACKGROUND: Bone cement implantation syndrome (BCIS) is characterized by hypoxia, hypotension, and the loss of consciousness during cemented arthroplasty; it may result in death. Its incidence has only been explored for hemiarthroplasty and THA after fracture or cancer. To our knowledge, there are no studies that comprehensively explore and compare the incidence of BCIS in other arthroplasty procedures. QUESTIONS/PURPOSES: (1) To report the incidence of BCIS in TKA, unicondylar knee arthroplasty, hip hemiarthroplasty, THA, shoulder arthroplasty, TKA, and revision THA and TKA; (2) to determine whether severe BCIS is associated with an increased risk of death within 30 days of surgery; and (3) to identify factors associated with the development of severe BCIS. METHODS: All patients undergoing cemented arthroplasty for any reason (TKA [11% cemented, 766 of 7293], unicondylar knee arthroplasty [100% cemented, 562 procedures], hip hemiarthroplasty for femur fractures [100% cemented, 969 procedures], THA [8% cemented, 683 of 8447], shoulder arthroplasty [84% cemented, 185 of 219], and revision arthroplasty of the hip and knee [36% cemented, 240 of 660]) between January 2008 and August 2019 were considered for inclusion in the current retrospective observational study. Fixation choice was dependent on surgeon preference (THA and TKA), prosthesis design (shoulder arthroplasty), or bone quality (revision arthroplasty). The following procedures were excluded because of insufficient data: < 1% (1 of 766) of TKAs, 1% (4 of 562) of unicondylar knee arthroplasties, 6% (54 of 969) of hip hemiarthroplasties, 1% (6 of 683) of THAs, 6% (12 of 185) of shoulder arthroplasties, and 14% (34 of 240) of revision procedures. This resulted in a final inclusion of 3294 procedures (765 TKAs [23%], 558 unicondylar knee arthroplasties [17%], 915 hip hemiarthroplasties [28%], 677 THA [21%], 173 shoulder arthroplasties [5%], and 206 revision arthroplasties [6%]), of which 28% (930 of 3294) had an emergent indication for surgery. Of the patients, 68% (2240 of 3294) were females, with a mean age of 75 ± 11 years. All anesthetic records were extracted from our hospital's database, and the severity of BCIS was retrospectively scored (Grade 0 [no BCIS], Grade 1 [O2% < 94% or fall in systolic blood pressure of 20% to 40%], Grade 2 [O2% < 88% or fall in systolic blood pressure of > 40%], and Grade 3 [cardiovascular collapse requiring CPR]). Procedures were dichotomized into no or moderate BCIS (Grades 0 and 1) and severe BCIS (Grades 2 and 3). The adjusted 30-day mortality of patients with severe BCIS was assessed with a multivariate Cox regression analysis. A multivariate logistic regression analysis was performed to identify factors associated with the development of severe BCIS. RESULTS: BCIS occurred in 26% (845 of 3294) of arthoplasty procedures. The incidence was 31% (282 of 915) in hip hemiarthroplasty, 28% (210 of 765) in TKA, 24% (165 of 677) in THA, 23% (47 of 206) in revision arthroplasty, 20% (113 of 558) in unicondylar knee arthroplasty, and 16% (28 of 173) in shoulder arthroplasty. Patients with severe BCIS were more likely (hazard ratio 3.46 [95% confidence interval 2.07 to 5.77]; p < 0.001) to die within 30 days of the index procedure than were patients with less severe or no BCIS. Factors independently associated with the development of severe BCIS were age older than 75 years (odds ratio 1.57 [95% CI 1.09 to 2.27]; p = 0.02), American Society of Anesthesiologists Class III or IV (OR 1.58 [95% CI 1.09 to 2.30]; p = 0.02), and renal impairment (OR 3.32 [95% CI 1.45 to 7.46]; p = 0.004). CONCLUSION: BCIS is common during cemented arthroplasty; severe BCIS is uncommon, but it is associated with an increased risk of death within 30 days of surgery. Medically complex patients undergoing hip hemiarthroplasty may be at particular risk. Patients at high risk for severe BCIS (renal impairment, ASA III/IV, and age older than 75 years) should be identified and preventive measures such as medullary lavage before cementation, femoral venting, and avoidance of excessive pressurization of implants should be taken to reduce the likelihood and consequences of BCIS. Because of the increased risk of periprosthetic fractures in uncemented hip stems, factors associated with the development of BCIS should be weighed against the risk factors for sustaining periprosthetic fractures (poor bone quality, female sex) to balance the risks of fixation method against those of BCIS for each patient. LEVEL OF EVIDENCE: Level III, therapeutic study.

Is obesity associated with short-term revision after total knee arthroplasty? An analysis of 121,819 primary procedures from the Dutch Arthroplasty Register.

BACKGROUND: The prevalence of obesity is increasing. The association with knee osteoarthritis is well documented, resulting in the population requesting total knee arthroplasty (TKA) for invalidating symptoms to be heavier in nature. The purpose of the current analysis was to assess the association between preoperative body mass index (BMI) and short-term revision rate after TKA. The secondary aim was to investigate the influence of implant fixation method on the association between BMI and survivorship. METHODS: This is a retrospective analysis of prospectively collected registry data (Dutch Arthroplasty Register; LROI). All primary TKA procedures in patients >18 years of age with registered BMI were selected (n = 121,819). Non-obese patients (BMI 18-25) were compared with overweight (BMI 25-30) and class I-III obese (BMI >30, >35, >40) patients. Crude all-cause revision rates were calculated using competing risk analysis. Adjusted hazard ratios (HRs) were determined with Cox multivariable regression analyses for all-cause, septic and aseptic revision and secondary patellar resurfacing. RESULTS: Revision rates were 3.3% for non-obese patients, 3.5% for overweight patients, 3.7% for class I obese patients, 3.6% for class II obese patients and 3.7% for class III obese patients. Class III obese patients had a significant higher risk for septic revision compared with non-obese patients (HR 1.53, 95% confidence interval (CI) 1.06-2.22). Class I obese patients had a higher risk for secondary patellar resurfacing (HR 1.52, 95% CI 1.12-2.08). All-cause and aseptic revision rates were similar between BMI groups. CONCLUSIONS: Obesity appeared to be associated with some short-term revision risks after TKA, but was not associated with an overall increase in revision rate.

Impact of COVID-19 on orthopaedic care: a call for nonoperative management.

BACKGROUND: Surgical specialties face unique challenges caused by SARS-COV-2 (COVID-19). These disruptions will call on clinicians to have greater consideration for non-operative treatment options to help manage patient symptoms and provide therapeutic care in lieu of the traditional surgical management course of action. This study aimed to summarize the current guidance on elective surgery during the COVID-19 pandemic, assess how this guidance may impact orthopaedic care, and review any recommendations for non-operative management in light of elective surgery disruptions. METHODS: A systematic search was conducted, and included guidance were categorized as either "Selective Postponement" or "Complete Postponement" of elective surgery. Selective postponement was considered as guidance that suggested elective cases should be evaluated on a case-by-case basis, whereas complete postponement suggested that all elective procedures be postponed until after the pandemic, with no case-by-case consideration. In addition, any statements regarding conservative/non-operative management were summarized when provided by included reports. RESULTS: A total of 11 reports from nine different health organizations were included in this review. There were seven (63.6%) guidance reports that suggested a complete postponement of non-elective surgical procedures, whereas four (36.4%) reports suggested the use of selective postponement of these procedures. The guidance trends shifted from selective to complete elective surgery postponement occurred throughout the month of March. The general guidance provided by these reports was to have an increased consideration for non-operative treatment options whenever possible and safe. As elective surgery begins to re-open, non-operative management will play a key role in managing the surgical backlog caused by the elective surgery shutdown. CONCLUSION: Global guidance from major medical associations are in agreement that elective surgical procedures require postponement in order to minimize the risk of COVID-19 spread, as well as increase available hospital resources for managing the influx of COVID-19 patients. It is imperative that clinicians and patients consider non-operative, conservative treatment options in order to manage conditions and symptoms until surgical management options become available again, and to manage the increased surgical waitlists caused by the elective surgery shutdowns.