Impact of previous lumbar spine surgery on total hip arthroplasty and vice versa: How long should we be concerned about mechanical failure?

INTRODUCTION: This registry study aims to assess the prevalence and demographic characteristics of patients with lumbar spine (LS) surgical procedures who undergo total hip arthroplasty (THA), to compare the long-term survival and causes of failure of THA in patients who previously underwent LS fusion and non-fusion surgical procedures, and to evaluate the risk of undergoing a revision LS surgery after THA. MATERIALS AND METHODS: Patients who underwent LS surgery followed by THA were identified by cross-referencing data from the Orthopedic Prosthetic Implants Registry and the Regional Hospital Discharge Database. Three groups of THA patients were identified: patients who underwent previous lumbar surgery with fusion (LS fusion-THA), without fusion (LS non-fusion-THA), and a control group with only THA (No LS surgery-THA). Demographic data, THA survival, number and causes of failure, and data on revision procedures on THA and LS were collected. RESULTS: Of the total of 79,984 THA, 2.2% of patients had a history of LS procedures. THA only patients showed better results, while patients in the LS fusion-THA group had worse implant survival at 5-year follow-up. In the LS fusion-THA and LS non-fusion-THA, mechanical THA failures were more frequent in the first two years after implantation. There were no differences between groups regarding the risk of undergoing LS revision surgery. CONCLUSIONS: LS surgery negatively affects THA survivorship. In patients who previously underwent LS fusion and non-fusion surgical procedures, most THA failure occurs in the first two years after implant. The study contributes to the understanding of the relationship between the hip and the LS and provides useful guidance for clinical practice.

Higher failure rate of secondary patellar resurfacing following bicompartmental knee arthroplasty.

INTRODUCTION: The role of secondary patellar resurfacing (SPR) in anterior knee pain (AKP) is still debated in literature. A regional arthroplasty registry was investigated, aiming to: (1) assess the survival rate of SPR; and (2) compare SPR to tricompartmental TKA. MATERIALS AND METHODS: The regional arthroplasty registry RIPO was investigated about all SPRs performed after bicompartmental arthroplasty. The survival rates and the reasons for revision were assessed as any other factor that could have influenced implants failure. SPR survivorship was compared to tricompartmental TKAs. RESULTS: 406 SPRs performed after bicompartmental arthroplasty were analyzed. The survival rates were 80.6% (CI 95% 75.9-84.5) at 5 years and 77.6% (CI 95% 72.4-82) at 7 years. Half of the SPRs was performed 0.9-2.4 years after the index bicompartmental arthroplasty. SPR achieved lower survival than tricompartmental TKA (80.6% vs 96.7%, p < 0.001), with an adjusted hazard ratio for failure of 5.5 (CI 95% 4.2-7.1, p < 0.001). SPRs performed within 2 years after primary implant had a significantly higher rates of failure when compared to tricompartmental TKA (HR: 6.4, CI 95% 4.8-8.4, p < 0.001). CONCLUSION: SPR after bicompartmental knee arthroplasty showed modest 5- and 7-year survival rates, worse than primary tricompartmental TKA. When SPRs are performed within 2 years after primary arthroplasty, a significant higher risk of failure should be expected, highlighting than appropriate pre-operative work-up and patient selection is crucial for SPR successful outcome. LEVEL OF EVIDENCE: III, therapeutic study.

Perioperative treatment with TNF inhibitors does not affect survival of total hip arthroplasty in inflammatory arthritis: A registry-based cohort study.

OBJECTIVES: Aim of this study was to investigate the effect of perioperative exposure to TNF inhibitors (TNFi) on the long-term survival of total hip arthroplasty (THA) in inflammatory arthritis patients from a large regional register of arthroplasty procedures (RIPO). METHODS: This study is a retrospective analysis of data from RIPO for THAs performed between 2008 and 2019. After extraction of the procedures of interest from the RIPO dataset, cross-matching with administrative databases were used to identify patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), primary osteoarthritis (OA), and treatments of interest. Three different cohorts of patients were identified: perioperative TNFi-treated patients (6 months before or after the surgery), perioperative non-bDMARD/tsDMARD (biologic or targeted-synthetic disease modifying antirheumatic drugs), and OA. RESULTS: At an average follow-up of 5 years, survival rates (using any revision surgery as an endpoint) were not significantly different when perioperative TNFi users and non-bDMARD/tsDMARD patients were compared (p = 0.713), and between TNFi-treated and OA controls (p = 0.123). At the latest available follow-up, 2.5% patients in the TNFi cohort, 3% in the non-bDMARD/tsDMARD cohort, and 0.8% in the OA cohort underwent revision surgery. No significant differences were found comparing the risk of postoperative infection or aseptic loosening among groups. CONCLUSION: Risk of revision surgery is not increased in patients with inflammatory arthritis perioperatively exposed to TNFi. Our results support the long-term safety of this class of molecules on survival of prosthetic implants.

Lateral unicompartmental knee arthroplasty (UKA) showed a lower risk of failure compared to medial unicompartmental knee arthroplasty in the Register of Prosthetic Orthopedic Implants (RIPO).

INTRODUCTION: The present study aimed to investigate differences in survivorship between medial and lateral unicompartmental knee arthroplasty (UKA) by analyzing the data of an Italian regional registry. The hypothesis was that, according to recent literature, lateral implants have comparable survivorship with regard to the medial implants. MATERIALS AND METHODS: The Register of Orthopaedic Prosthetic Implants (RIPO) of Emilia-Romagna (Italy) database was searched for all UKAs between July 1, 2000, and December 31, 2019. For both cohorts, subject demographics and reasons for revision were presented as a percentage of the total cohort. Kaplan-Meier survivorship analysis was performed using revision of any component as the endpoint and survival times of unrevised UKAs taken as the last observation date (December 31, 2019, or date of death). RESULTS: Patients living outside the region and symmetrical implants (which do not allow the compartment operated to be traced) were excluded. 5571 UKAs implanted on 5172 patients (5215 medial UKAs and 356 lateral UKAs) were included in the study. The survivorship analysis revealed 13 failures out of 356 lateral UKAs (3.7%) at a mean follow-up of 6.3 years and 495 failures out of 5215 medial UKAs (9.5%) at a mean follow-up of 6.7 years. The medial UKAs had a significantly higher risk of failure, with a Hazard Ratio of 2.6 (CI 95% 1.6-4.8; p < 0.001), adjusted for age, gender, weight, and mobility of the insert. Both the groups revealed a good survival rate, with 95.2% of lateral implants and 87.5% of medial implants still in situ at 10 years of follow-up. CONCLUSIONS: Lateral UKA is a safe procedure showing longer survivorship than medial UKAs (95.2% and 87.5% at 10 years, respectively) in the present study. LEVEL OF EVIDENCE: Level 3, therapeutic study.

Long-term survivorship of an exchangeable-neck hip prosthesis with a Ti-alloy/Ti-alloy neck-stem junction.

INTRODUCTION: Breakage of exchangeable-neck (EN) and adverse local tissue reactions (ALTRs) to neck-stem junction (NSJ) damage products are responsible for increasing the revision rate of EN hip prostheses. We investigated the survivorship of an EN hip prosthesis including a NSJ with both components made of titanium alloy (Ti-alloy/Ti-alloy) to assess whether, and to what extent, EN breakage and NSJ damage affected implant survivorship. MATERIALS AND METHODS: Using data from a hip replacement registry, we determined survivorship of 2857 EN prostheses. Long-offset configurations of head and EN were implanted in heavy (> 90 kg) patients only in 23 hips. We investigated under which conditions EN breakages or ALTRs occurred. We also measured titanium (Ti) and vanadium (V) blood concentrations in 24 patients with a unilateral well-working prosthesis. RESULTS: The 17-year survival rates for any reason and aseptic loosening of any component were 88.9% (95%CI 87.5-90.1; 857 hips at risk) and 96.9% (95%CI 96.0-97.6), respectively. There were two cases of EN breakage and one case of ALTR (metallosis), due to rim-neck impingement, out of 276 revisions. After an average period of 9.8 years (range 7.8-12.8 years), the maximum Ti and V blood concentrations in patients with a well-working prosthesis were 5.0 µg/l and 0.16 µg/l, respectively. CONCLUSION: The present incidence of EN breakage or ALTR is lower than those reported in other studies evaluating EN hip prosthesis survivorship. This study suggests that (i) the risk of EN breakage is reduced by limiting the use of long-offset configurations in heavy patients and (ii) Ti-alloy/Ti-alloy NSJ damage products do not promote ALTR nor significantly alter the rate of implant loosening. Since design decisions and implant configuration determine the NSJ strength, the NSJ strength in working conditions must be thoroughly investigated to proper define the clinical indications for any EN design.

Classification Scheme of Heating Risk during MRI Scans on Patients with Orthopaedic Prostheses.

Due to the large variety of possible clinical scenarios, a reliable heating-risk assessment is not straightforward when patients with arthroplasty undergo MRI scans. This paper proposes a simple procedure to estimate the thermal effects induced in patients with hip, knee, or shoulder arthroplasty during MRI exams. The most representative clinical scenarios were identified by a preliminary frequency analysis, based on clinical service databases, collecting MRI exams of 11,658 implant carrier patients. The thermal effects produced by radiofrequency and switching gradient fields were investigated through 588 numerical simulations performed on an ASTM-like phantom, considering four prostheses, two static field values, seven MR sequences, and seven regions of imaging. The risk assessment was inspired by standards for radiofrequency fields and by scientific studies for gradient fields. Three risk tiers were defined for the radiofrequency, in terms of whole-body and local SAR averages, and for GC fields, in terms of temperature elevation. Only 50 out of 588 scenarios require some caution to be managed. Results showed that the whole-body SAR is not a self-reliant safety parameter for patients with metallic implants. The proposed numerical procedure can be easily extended to any other scenario, including the use of detailed anatomical models.

Constraint in complex primary total knee arthroplasty: rotating hinge versus condylar constrained implants.

INTRODUCTION: Condylar constrained knee arthroplasties (CCKAs) and rotating hinge knee arthroplasties (RHKAs) achieved good outcomes in complex primary total knee arthroplasties (TKAs); however, long-term comparative studies are few. Using an arthroplasty registry, we sought to assess and compare in CCKAs and RHKAs: (1) the intra-operative rates of complications, (2) the survival rates, (3) the reasons for revision, and (4) the adjusted hazard ratios for failure. MATERIALS AND METHODS: 1432 constrained implants in primary TKAs performed for non-oncological indications were included: 703 RHKAs, 729 CCKAs. The two groups were comparable regarding age and gender. Kaplan-Meier curves were used to compare survival rates, multivariate analyses to assess the hazard ratios for failures. RESULTS: The mean follow-up was 4.1 years (range 0-16.3) for CCKAs and 6.8 years (0-18.1) for RHKAs. The intra/peri-operative complications were similar in both the cohorts, with similar rates of femoral and tibial fractures. 10-year implant survival rates were similar in both the cohorts (91.9%, CI 95% 89.2-93.9% in RHKAs; 93.4%, CI 95% 90.3-95.6% in CCKAs). Periprosthetic infection was the most common reason for revision in the two cohorts, followed by aseptic loosening. Breakage occurred in 3 RHKAs (0.4%). CCKAs and RHKAs had a similar distribution of revision causes. Males aged less than 60 had significantly more failures, regardless the constraint degree. Unstemmed CCKAs significantly failed more than RHKAs and stemmed CCKAs. CONCLUSIONS: Both modern CCKAs and RHKAs are viable long-term solutions in complex primary TKAs. More failures should be expected in males aged less than 60. LEVEL OF EVIDENCE: IV, Therapeutic study.

The influence of bearing surfaces on revisions due to dislocations in total hip arthroplasty.

INTRODUCTION: Recurrent dislocations are still the most frequent reason for revision in total hip arthroplasty (THA). The impact of bearing surfaces on dislocations is still controversial. We hypothesized that: (1) bearing surfaces influence the revisions due to dislocations; (2) ceramic-on-ceramic reduced the revisions for dislocations in adjusted models; (3) Delta-on-Delta bearings reduced the revisions for dislocations in comparison to surfaces with cross-linked polyethylene. MATERIALS AND METHODS: The regional arthroplasty registry was enquired about bearing surfaces and revisions for dislocations and instability. Unadjusted and adjusted rates were provided, including sex, age (<65 years or ≥65 years), head diameter (≤28 mm or >28 mm; <36 mm or ≥36 mm) as variables. 44,065 THAs were included. RESULTS: The rate of revisions for dislocations was significantly lower in ceramic-on-ceramic and metal-on-metal bearings (unadjusted rates). After adjusting for age, sex, and head size (36 and 28 mm), hard-on-hard bearings were protective (p < 0.05): ceramic-on-ceramic had a lower risk of revisions due to dislocation than ceramic-on-polyethylene (HR 1.6, 95% CI 1.2-2.2 p = 0.0009). The rate of revisions for dislocation was similar in bearings with cross-linked polyethylene and Delta-on-Delta articulations, in unadjusted and adjusted models. CONCLUSION: Bearings with conventional polyethylene were more predisposed to dislocations. Currently adopted bearings exerted no significant influence on revisions due to dislocations. These findings could be primarily related to wear, but due to the time distribution, soft tissue envelopes and surface tension may also play a role. Pre-clinical biomechanical evaluations and prospective matched cohort studies are required to draw definitive conclusions.

Does total hip arthroplasty have a higher risk of failure in patients who undergo lumbar spinal fusion?

AIMS: Total hip arthroplasty (THA) patients undergoing or having a prior lumbar spine fusion (LSF) have an increased risk of mechanical complications. The aim of this registry-based, retrospective comparative cohort study is to assess the longer term survival of THA in patients who have undergone a LSF during a 17-year period (2000 to 2017). METHODS: A registry-based population study was conducted on 679 patients who underwent both THA and LSF surgeries. Patients were identified from the regional arthroplasty data base and cross linked to patients with LSF from the regional hospital discharge database between 2000 and 2017. Demographic data, diagnosis leading to primary THA, primary implant survival, perioperative complications, number and causes of failure, and patients requiring revision arthroplasty were collated and compared. For comparison, data from 67,919 primary THAs performed during the same time time period were also retrieved and analyzed. RESULTS: Patients undergoing THA and LSF showed homogeneous demographic data compared to those undergoing THA alone, but a significantly lower eight-year THA implant survival (96.7 vs 96.0, p = 0.024) was observed. Moreover, THA plus LSF patients showed increased incidence of mechanical complications in the first two years after THA surgery compared to THA alone patients. CONCLUSION: This registry-based population study shows that approximately 679 (1%) THA patients were subjected to LSF. Patients undergoing THA and LSF have an increased risk of mechanical complications with their THA and a slightly increased risk of revision arthroplasty. Cite this article: Bone Joint J 2021;103-B(3):486-491.

Delta-on-Delta Ceramic Bearing Surfaces in Revision Hip Arthroplasty.

BACKGROUND: Fourth-generation ceramic-on-ceramic couplings were developed to improve ceramic toughness and strength. Encouraging outcomes in primary total hip arthroplasty were reported. This coupling was proposed as an attractive option even in the case of revision procedures, particularly in younger patients with a longer life expectancy. However, the pertinent literature is scarce. Thus, a registry study was conducted to investigate the midterm survival rates and reasons for re-revision of the fourth-generation ceramic-on-ceramic bearing surfaces in revision hip arthroplasties. METHODS: A total of 327 revision implants (all the components were exchanged) with BIOLOX Delta couplings were investigated using the regional orthopedic registry RIPO. The demographics, the survival rates, and the reasons for re-revision were assessed. Revisions with bearings other than Delta were compared. RESULTS: Delta bearings achieved a survival rate of 90.5% at 7 years, with stable results. Twenty-six (8%) re-revisions occurred at a mean follow-up of 4.1 years. And 2.8% of the re-revisions were due to recurrent dislocations; 1.5% of the cases were due to cup aseptic loosening. Septic loosening occurred in 1.6% of the cases. No ceramic fractures were reported. When compared to revisions with bearings other than Delta-on-Delta, Delta coupling cohort achieved similar performances at 5 and 7 years. Lower, nonsignificant rates of aseptic and septic loosening were reported in Delta cohort. CONCLUSION: Delta-on-Delta couplings demonstrated to be reliable bearing surfaces in revision settings at a midterm follow-up. Clinical studies and longer follow-ups are required to investigate potential adverse effects, like squeaking and fractures, and confirm these preliminary findings. LEVEL OF EVIDENCE: Level III, therapeutic study.

Long-term survivorship of a medial-pivot total knee system compared with other cemented designs in an arthroplasty registry.

BACKGROUND: The Orthopaedic Data Evaluation Panel (ODEP) monitors the performance of primary total knee arthroplasty (TKA) implants against guidance provided by the National Institute for Health and Care Excellence (NICE) and issues ratings based upon survivorship data meeting or exceeding 95 % at 10-year follow-up. The objectives of the current study were to determine if the survivorship for the ADVANCE Medial-Pivot System in an arthroplasty registry exceeds this threshold and if its survivorship is significantly different than that of all other cemented bi-, tricompartmental, minimally stabilized, and fixed bearing TKAs in the same registry. METHODS: The database of an arthroplasty registry was searched for all TKAs performed with the subject system and all other cemented TKAs. The Kaplan-Meier survivorship for the subject system was compared to the NICE criteria and also that of all other cemented TKAs. Complication modes were also examined for the two groups. RESULTS: The 10-year survivorship for the included 506 TKAs using the subject system (96.3 %) exceeded the NICE guidelines of 95 % at 10 years. Survivorship also exceeded that of all other cemented TKAs (95.7 %) in the same registry, but the difference was not significantly different. CONCLUSIONS: The subject system was associated with survivorship that exceeds the NICE guidelines at 10 years and is similar to that of other cemented TKA systems. The use of this unique tibial insert design does not negatively impact component survivorship.

Long-term survivorship and complication rate comparison of a cementless modular stem and cementless fixed neck stems for primary total hip replacement.

PURPOSE: Modular necks used in total hip replacement (THR) have become an increasingly discussed topic with the recent recall of multiple modular systems, but it is anticipated that outcomes for these devices are highly design-specific. The objectives of this study were to determine if the survivorship and complication rates of a specific modular femoral stem (PROFEMUR® Z, MicroPort Orthopedics Inc., Arlington, TN, USA) were significantly lower than those of all cementless fixed neck stems in an arthroplasty registry. METHODS: The database of an arthroplasty registry was searched for all patients implanted with a specific modular stem and all those implanted with cementless fixed neck stems. Kaplan-Meier survivorship and complication rates were compared between the two groups. RESULTS: The 12-year survivorship of the modular stem (95.8%) was not significantly less than that of all cementless fixed neck stems (96.1%). There was also no difference in revision rates for dislocation, periprosthetic fractures, aseptic loosening or septic loosening between the two groups. CONCLUSIONS: The use of the specific modular stem did not adversely affect long-term component survivorship or complication rates when compared to all cementless fixed neck THRs in an arthroplasty registry.

Unicompartmental knee arthroplasty: 11-year experience from 3929 implants in RIPO register.

BACKGROUND: Since 2000, the Register of Prosthetic Orthopedic Implants (RIPO) has been following all hip, knee, and shoulder arthroplasties in the Emilia-Romagna region, comprising 4.5 million inhabitants, in northern Italy. The aim of the present analysis was to present the main figures of unicompartmental knee implants processed from the Registry. METHODS: During the period 2000-2011, 3929 unicompartmental knee arthroplasties were performed on 3645 resident patients, of which 71% were females. The medial condyle was treated in 94% of cases, where mean age at surgery was 67.3 years and mean body weight was 76.6 kg. The main outcome measure was time to revision of at least one single component. The Kaplan-Meier survival and Cox multivariate analyses have been applied. RESULTS: At 10-year follow-up, the percentage of survival was 86.8% (confidence interval (CI) at 95% was 84.1-89.5); total aseptic loosening represented 42% of the causes of failure, pain represented 15%, and sepsis represented 11%. Age at surgery significantly influences the survival of the prosthesis, whatever the reason for revision, while the type of tibial component (monoblock or metal tray) does not appear to be a determinant. Septic failure is not prevented by the use of antibiotic-loaded cement. CONCLUSION: Results are comparable to main orthopedic registries from Scandinavia, Australia, and New Zealand, even if some differences can be highlighted.

Monocyte chemoattractant protein 1 expression in synovial fluid of patients with total hip arthroplasty.

Monocyte chemoattractant protein 1 (MCP-1) is a member of the chemokines family that stimulates monocyte chemotaxis and whose expression is induced during osseous inflammation. Total hip arthroplasty (THA) now uses ceramic-on-ceramic (cer-cer) or metal-on-metal (met-met) coupling that is considered the bearing of new generation, with improved performance compared with the previous polyethylene bearings. While the ceramic on ceramic is universally considered highly biocompatible, met-met coupling can induce hypersensitivity correlated to immunological response. This study aimed at quantifying the MCP-1 levels in synovial fluid of THA patients with these two articular couplings; synovial fluid of osteoarthritic patients who underwent primary THA was used as a control. The presence of wear particles originating from the prostheses was also assessed in the synovial fluid by scanning electron microscopy and energy dispersive X-ray spectroscopy. The MCP-1 levels in the synovial fluid of 17 patients with met-met coupling were significantly higher than in 13 patients with cer-cer coupling and in seven controls; median MCP-1 level was 919 pg/mL in the cer-cer group, 4274 pg/mL in the met-met group, and 326 pg/mL in the control group. No correlation was found between MCP-1 levels and the presence of wear particles in the synovial fluid, time from surgery, or periprosthetic osteolysis. We conclude that the presence of the prosthesis is responsible for an increase in the level of MCP-1; moreover, the significantly higher level of this chemokine in met-met coupling can be related to inflammatory and possibly hypersensitivity processes induced by metal ions.