Outcomes in revision total knee arthroplasty (Review)

High-concentration continuous local antibacterial perfusion therapy: safety and potential efficacy for acute and chronic periprosthetic knee joint infection

BACKGROUND

Periprosthetic joint infections (PJIs) following total knee arthroplasty (TKA) are among the most challenging pathologies to manage. Recently, continuous local antibiotic perfusion (CLAP) therapy has been introduced for treating musculoskeletal infections in orthopedics. This study aimed to determine the outcomes and risks of CLAP therapy combined with conventional treatment for PJIs after TKA.

METHODS

We retrospectively evaluated 14 patients with PJIs. For acute PJIs, CLAP therapy was performed alongside debridement, intravenous antibiotics, and implant retention. For chronic PJIs, a two-stage revision with CLAP therapy and intravenous antibiotics was performed. Implants were replaced with a cement mold incorporating CLAP therapy, followed by revision surgery after 3 months. For all patients, 120 mg/day of gentamicin (GM) was locally administered into the knee joint for 2 weeks as part of CLAP therapy, in combination with perioperative intravenous antibiotics.

RESULTS

Five patients developed acute PJIs, and nine developed chronic PJIs after TKA. The mean follow-up period was 18.4 (15.2-21.1) months. All five patients with PJIs treated with one-stage surgery (debridement and insert exchange only) successfully preserved their implants. Among the nine patients with chronic PJIs, seven underwent CLAP therapy combined with two-stage revision surgery, resulting in successful treatment without relapse, whereas the remaining two patients were initially treated with one-stage surgery and CLAP therapy but failed to retain their implants, and subsequently required additional two-stage revision surgery, which ultimately succeeded. No adverse effects from GM were reported.

CONCLUSIONS

Our results suggest that CLAP therapy is safe and may be effective for treating acute and most chronic PJIs after TKA.

Influence of Diabetes Mellitus on Postoperative Complications After Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

Background and Objectives: Total knee arthroplasty (TKA) is an effective treatment option for severe knee osteoarthritis. Understanding the impact of diabetes mellitus (DM) on postoperative outcomes is crucial for improving patient satisfaction after TKA. This study aimed to investigate the influence of DM on postoperative complications and mortality after TKA. Materials and Methods: We conducted a systematic review and meta-analysis by searching relevant studies published before December 2023 in the PubMed, EMBASE, Cochrane Library, Medline, and Web of Science databases. The assessment included demographic data, comorbidities, and postoperative complications after primary TKA for both DM and non-DM patients. The odds ratio (OR) was used to represent the estimate of risk of a specific outcome. Results: Thirty-nine studies were finally included in this meta-analysis. Patients with DM had higher rates of periprosthetic joint infection (OR: 1.71, 95% confidence interval [CI]: 1.46-2.00, p < 0.01) and prosthesis revision (OR: 1.37, 95% CI: 1.23-1.52, p < 0.01). Moreover, patients with DM showed an elevated incidence of pneumonia (OR: 1.54, 95% CI: 1.15-2.07, p < 0.01), urinary tract infection (OR: 1.86, 95% CI: 1.07-3.26, p = 0.02), and sepsis (OR: 1.61, 95% CI: 1.46-1.78, p < 0.01). Additionally, the postoperative risk of cardiovascular (OR: 2.49, 95% CI: 1.50-4.17, p < 0.01) and cerebrovascular (OR: 2.38, 95% CI: 1.48-3.81, p < 0.01) events was notably higher in patients with DM. The presence of DM increased the risk of deep vein thrombosis (OR: 1.58, 95% CI: 1.22-2.04, p < 0.01), but did not lead to an increased risk of pulmonary embolism. Most importantly, DM was associated with a higher mortality rate within 30 days after TKA (OR: 1.27, 95% CI: 1.02-1.60, p = 0.03). Conclusions: Patients with DM exhibited a higher rate of postoperative complications after TKA, and DM was associated with a higher mortality rate within 30 days after TKA. It is crucial to educate patients about the perioperative risk and develop evidence-based guidelines to prevent complications after TKA.

Impact of systemic lupus erythematosus (SLE) on outcomes following aseptic and septic revision total knee arthroplasty: an analysis of the 2005-2018 nationwide inpatient sample

Systemic lupus erythematosus (SLE) can adversely affect surgical outcomes, and the impact on revision total knee arthroplasty (TKA) outcomes is unclear. This study aimed to explore the impact of SLE on in-patient outcomes of revision TKA. The Nationwide Inpatient Sample (NIS) database from 2005 to 2018 was searched for patients aged ≥ 18 years old who received revision TKA. Patients with and without SLE were propensity score matched (PSM) at a 1:4 ratio. Associations between SLE and in-hospital outcomes were examined using regression analyses. The study included 133,054 patients, with 794 having SLE. After 1:4 PSM, data of 3,970 patients were analyzed (SLE, 794; non-SLE, 3,176). Multivariate-adjusted analyses revealed that SLE patients had a significantly higher risk of postoperative complications (adjusted odds ratio [aOR] = 1.23, 95% confidence interval [CI]: 1.05-1.44, p = 0.011), non-routine discharge (aOR = 1.22, 95% CI: 1.02-1.46, p = 0.028), major blood loss (aOR = 1.19), respiratory failure/mechanical ventilation (aOR = 1.79), acute kidney injury (AKI) (aOR = 1.47), and wound dehiscence (aOR = 2.09). SLE patients also had a longer length of hospital stay (aBeta = 0.31) and greater total hospital costs (aBeta = 6.35) compared to non-SLE patients. Among those with aseptic failure, SLE patients had a significantly higher risk of postoperative complications (aOR = 1.23) and non-routine discharge (aOR = 1.36). SLE is independently associated with worse in-hospital outcomes in patients undergoing revision TKA. This study highlights the importance of heightened vigilance and tailored perioperative management for patients undergoing major surgeries in the background of SLE. Key Points • SLE significantly increases the risk of non-routine discharge, major blood loss, respiratory failure, acute kidney injury, and wound dehiscence, in patients undergoing aseptic and septic revision TKA. • Patients with SLE experience longer hospital stays and higher hospital costs compared to those without SLE. • The study's findings highlight the necessity for healthcare providers to consider the presence of SLE as a critical factor in preoperative planning and postoperative care to improve outcomes in revision TKA patients.

Leveraging transfer learning for predicting total knee arthroplasty failure from post-operative radiographs

Purpose

The incidence of both primary and revision total knee arthroplasty (TKA) is expected to rise, making early recognition of TKA failure crucial to prevent extensive revision surgeries. This study aims to develop a deep learning (DL) model to predict TKA failure using radiographic images.

Methods

Two patient cohorts who underwent primary TKA were retrospectively collected: one was used for the model development and the other for the external validation. Each cohort encompassed failed and non-failed subjects, according to the need for TKA revision surgery. Moreover, for each patient, one anteroposterior and one lateral radiographic view obtained during routine TKA follow-up, were considered. A transfer learning fine-tuning approach was employed. After pre-processing, the images were analyzed using a convolutional neuronal network (CNN) that was originally developed for predicting hip prosthesis failure and was based on the Densenet169 pre-trained on Imagenet. The model was tested on 20% of the images of the first cohort and externally validated on the images of the second cohort. Metrics, such as accuracy, sensitivity, specificity and area under the receiving operating characteristic curve (AUC), were calculated for the final assessment.

Results

The trained model correctly classified 108 out of 127 images in the test set, providing a classification accuracy of 0.85, sensitivity of 0.80, specificity of 0.89 and AUC of 0.86. Moreover, the model correctly classified 1547 out of 1937 in the external validation set, providing a balanced accuracy of 0.79, sensitivity of 0.80, specificity of 0.78 and AUC of 0.86.

Conclusions

The present DL model predicts TKA failure with moderate accuracy, regardless of the cause of revision surgery. Additionally, the effectiveness of the transfer learning fine-tuning approach, leveraging a previously developed DL model for hip prosthesis failure, has been successfully demonstrated.

Level of Evidence

Level III, diagnostic study.

[Unicondylar knee arthroplasties demonstrate a significantly increased risk of aseptic revisions compared with unconstrained and constrained TKA : Analysis of aseptic revisions after unicondylar and primary total knee arthroplasty of the German Arthroplasty Register]

OBJECTIVE

Owing to the ageing population the implantation rate of total knee arthroplasty (TKA) continues to rise. Aseptic revisions in primary TKA are one of the main causes of revision. The aim of the following study was to determine the incidence of and reasons for aseptic revision in constrained and unconstrained TKA and in unicondylar knee arthroplasty (UKA).

METHODS

The data collection was carried out with the help of the German Arthroplasty Register (EPRD). The reasons for aseptic revision surgery were worked out using this. The incidence and the comparison of aseptic revisions were analysed with the aid of Kaplan-Meier estimates. A multiple Chi-squared test with the Holm method was used to identify group differences in collateral ligament deficiencies.

RESULTS

In total, 300,998 cases of knee arthroplasties were analysed, of which 254,144 (84.4%) were unconstrained TKA, 9993 (3.3%) were constrained TKA and 36,861 (12.3%) were UKA. The rate of aseptic revisions was significantly increased compared with unconstrained and constrained TKA (p < 0.0001). In constrained TKA, a revision rate of 2.0% for aseptic reasons was reported, whereas in unconstrained TKA 1.1% and in UKA 2.7% revision surgeries were identified. After 7 years the rates of aseptic revisions amounted to 3.3% for constrained TKA, 2.8% for unconstrained TKA and 7.8% for UKA. Ligament instability was the most common cause of aseptic revisions and accounted for 13.7% of unconstrained TKA. In constrained TKA ligament instability led to a revision in 2.8% of cases. In UKA, tibial loosening was identified to be the most common cause of revisions at 14.6%, whereas the progression of osteoarthritis was responsible for 7.9% of revisions. Ligament instability was observed in 14.1% of men compared with 15.9% of women in unconstrained TKA and in UKA in 4.6% of cases for both sexes.

CONCLUSION

In patients with UKA the rates of aseptic revision are significantly higher than in unconstrained and constrained TKA. Ligament instability was the most common cause of aseptic revision in unconstrained TKA. In UKA, tibial loosening was the most common cause of revision surgery, whereas the progression of osteoarthritis was the second most common cause. Comparable levels of ligament instability were observed in both sexes.

LEVEL OF EVIDENCE

 III, cohort study.

Knee osteoarthritis: disease burden, available treatments, and emerging options

Osteoarthritis (OA) is a prevalent condition that affects nearly 528 million people worldwide, including 23% of the global population aged ⩾40, and is characterized by progressive damage to articular cartilage, which often leads to substantial pain, stiffness, and reduced mobility for affected patients. Pain related to OA is a barrier to maintaining physical activity and a leading cause of disability, accounting for 2.4% of all years lived with disability globally, reducing the ability to work in 66% of US patients with OA and increasing absenteeism in 21% of US patients with OA. The joint most commonly involved in OA is the knee, which is affected in about 60%-85% of all OA cases. The aging population and longer life expectancy, coupled with earlier and younger diagnoses, translate into a growing cohort of symptomatic patients in need of alternatives to surgery. Despite the large number of patients with knee OA (OAK) worldwide, the high degree of variability in patient presentation can lead to challenges in diagnosis and treatment. Multiple society guidelines recommend therapies for OAK, but departures from guidelines by healthcare professionals in clinical settings reflect a discordance between evidence-based treatment algorithms and routine clinical practice. Furthermore, disease-modifying pharmacotherapies are limited, and treatment for OAK often focuses solely on symptom relief, rather than underlying causes. In this narrative review, we summarize the patient journey, analyze current disease burden and nonsurgical therapy recommendations for OAK, and highlight emerging and promising therapies-such as cryoneurolysis, long-acting corticosteroids, and gene therapies-for this debilitating condition.

Rate of complications and short-term Functional Results of Revision Total Knee Arthroplasty for Tibio-femoral Instability: do stability and range of motion are restored in 62 revisions

BACKGROUND

Tibio-femoral instability (TFI) due to ligament imbalance is a growing cause of revision total knee arthroplasty (TKA). The results are heterogeneous in the event of revision and literature is scarce regarding this issue particularly when use of hinge prostheses is not exclusive to manage this complication. Therefore, a retrospective investigation was conducted aiming to (1) analyze the one-year functional results, (2) determine the rate of complications after revision for TFI using posterior-stabilized or condylar constrained knees (CCK), 3) identify the factors that could influence the function outcome.

HYPOTHESIS

Patients undergoing revision TKA for TFI would show an improvement in Oxford Knee Score at one year postoperative.

METHODS

Sixty-two patients were included (40 females, 22 males) mean age 62,9 years ± 8.2 (range, 45,7-78,4). Instability was classified as instability in extension (n = 28), midflexion (n = 12), flexion (n = 12) or global (n = 15). Revisions were done because of isolated instability. Revision consisted in implant revision using a CCK (n = 42), a hinge prosthesis (n = 12) or an isolated polyethylene insert exchange (n = 8). Patients were assessed at one year by the difference between the preoperative Oxford Knee Score (OKS) and the score at one year postoperatively. The results were deemed satisfactory if the variation between preoperative OKS and one-year follow-up was greater than or equal to 5 points (Minimal Clinically Important Difference (MCID) following TKA). Complication rate and risk factors influencing the outcome were also analyzed.

RESULTS

Of the 62 patients, 59 could be assessed at one year using postoperative OKS (one death at 0.66 years from unrelated reason, and two had repeated revision within one year postoperative [1 aseptic loosening and 1 Co-Cr allergy]). Preoperative OKS was 15.5 points ± 7.1 (range, 2-37), rising to 28.9 points ± 8.7 (range, 11-45) at follow-up. The mean OKS improvement was 13.4 points ± 10.3 (range, -8 to 33) (p < 0.001) and 47 patients (79.6%) reached the MCID at follow-up. Female gender was associated with a worse evolution of OKS (-5.8, 95% CI: -11.26 to -0.34 (p = 0.038)). In contrast, there was no significant difference in the evolution of the OKS according to the type of TFI in extension or in flexion, in midflexion or global (p = 0.5). Likewise, there was no significant difference in the evolution of the OKS between RTKA using CCK, hinged prosthesis or isolated polyethylene insert exchange (p = 0.3). There was no recurrence of instability at final follow-up (3.04 years ± 1.5 (range, 0.66-6.25)). Revision for instability did not drive to stiffness since mean flexion prior to RTKA was 116 ° ± 13 ° (range, 90 ° to 130 °) versus 116.7 ° ± 12 ° (range, 90 ° to 130 °) at follow-up. Fourteen patients (22.6%) experienced postoperative complications, including 3 revisions (4.8%) at final follow-up.

CONCLUSION

RTKA for TFI leads to significant functional improvement at one-year postoperative. However, the risk of complications is almost high at 22.6%.

LEVEL OF EVIDENCE

IV; retrospective study.

Diagnostic Values of Serum Inflammatory Biomarkers after Hip and Knee Arthroplasty in Patients with Periprosthetic Joint Infection

One of the complications after total hip arthroplasty (THA) or total knee arthroplasty (TKA) is periprosthetic joint infection (PJI). Numerous studies have been performed to explore the value of biological parameters in the early identification of infection rates after THA and TKA. This study investigates alterations in inflammatory markers associated with PJI. This retrospective study focused on a cohort of patients with hip and knee arthroplasty treated between 2016 and 2022. CRP, ESR, and fibrinogen were observed preoperatively, on days one, three, six, and twenty-one postoperatively. From a total of 4076 THA and TKA performed during this period, 62 patients were identified with periprosthetic infections. We also identified the pathogens responsible for infections in order to assess if asymptomatic preoperative infections were involved in PJI. In patients with acute infections following TKA, days one and three postoperative recorded a CRP value below the expected range. The value of CRP in patients with early infection after THA was significantly increased on day six postoperative. ESR and fibrinogen values were not statistically significantly correlated with early PJI. The CRP level in acute PJI shows different patterns than those shown in the literature.

Unicondylar knee arthroplasty demonstrating a significant increased risk for aseptic revisions compared to unconstrained and constrained total knee arthroplasty: An analysis of aseptic revisions after unicondylar and primary total knee arthroplasty of the German Arthroplasty Registry

PURPOSE

Due to ageing population, the implantation rate of total knee arthroplasties (TKAs) is continuously growing. Aseptic revisions in primary knee arthroplasty are a major cause of revision. The aim of the following study was to determinate the incidence and reasons of aseptic revisions in constrained and unconstrained TKA, as well as in unicondylar knee arthroplasties (UKAs).

METHODS

Data collection was performed using the German Arthroplasty Registry. Reasons for aseptic revisions were calculated. Incidence and comparison of aseptic revisions were analysed using Kaplan-Meier estimates. A multiple χ2 test with Holm's method was used to detect group differences in ligament ruptures.

RESULTS

Overall, 300,998 cases of knee arthroplasty with 254,144 (84.4%) unconstrained TKA, 9993 (3.3%) constrained TKA and 36,861 (12.3%) UKA were analysed. Aseptic revision rate in UKA was significantly increased compared to unconstrained and constrained TKA (p < 0.0001). In constrained TKA, a 2.0% revision rate for aseptic reasons were reported after 1 year, while in unconstrained TKA 1.1% and in UKA, 2.7% of revisions were identified. After 7 years in constrained TKA 3.3%, in unconstrained TKA 2.8%, and in UKA 7.8% sustained aseptic revision. Ligament instability was the leading cause of aseptic revision accounting for 13.7% in unconstrained TKA. In constrained TKA, 2.8% resulted in a revision due to ligament instability. In the UKA, the most frequent cause of revisions was tibial loosening, accounting for 14.6% of cases, while progression of osteoarthritis accounted for 7.9% of revisions. Ligament instability was observed in 14.1% of males compared to 15.9% of females in unconstrained TKA and in 4.6% in both genders in UKA.

CONCLUSION

In patients with UKA, aseptic revision rates are significantly higher compared to unconstrained and constrained TKA. Ligament instability was the leading cause of aseptic revision in unconstrained TKA. In UKA, the most frequent cause of revisions was tibial loosening, while progression of osteoarthritis was the second most frequent cause of revisions. Comparable levels of ligament instability were observed in both sexes.

LEVEL OF EVIDENCE

Level III, cohort study.

Severity of knee osteoarthritis does not affect clinical outcomes following proximal fibular osteotomy - A systematic review and pooled analysis

Background & aims

Knee osteoarthritis (KOA) is a progressive degenerative disease of chronic nature. The mainstay of surgical management for KOA would be total knee arthroplasty. Joint preserving options like High Tibial Osteotomy (HTO) and Proximal Fibular Osteotomy (PFO) have been offered as an inexpensive option by knee preservation surgeons. Current literature on PFO outcomes lack of clarity for specific indications for offering PFO based on degree of severity of KOA. Therefore, this systematic review aims to critically evaluate clinical and radiological outcomes of PFO stratified by severity of KOA.

Methods

PubMed, Scopus, CINAHL and Google Scholar databases were searched. Eligible studies included those published up till August 2023, with 271 studies obtained. After duplicate removal, title-abstract screening, and a full text screen based on inclusion and exclusion criteria, 11 papers were included. 46 papers were further identified from snowballing of 7 existing systematic reviews, with 2 additional papers subsequently included.

Results

13 included articles analysed 788 knees. Our study found that indications based on KL grading of KOA do not seem to differ in terms of post-operative clinical outcomes (VAS score) and radiological measures also found that hip knee alignment was improved regardless of KL grading of KOA. Additionally, the most common post-operative complication reported was deep peroneal nerve palsy.

Conclusion

PFO is a viable knee joint preserving surgery for medial compartment KOA, however given the high risk for complications reported in the literature, surgeons should pay close attention to the neuroanatomical landmarks and techniques to avoid neurovascular injury.

Non-invasive quantitative assessment of induced component displacement can safely and accurately diagnose tibial component loosening in patients: A prospective diagnostic study

PURPOSE

Aseptic loosening often requires major, expensive and invasive revision surgery. Current diagnostic modalities merely show indirect signs of loosening. A recent proof of concept study proposed a non-invasive technique for the quantitative and visual assessment of implant movement as a diagnostic aid for tibial component loosening. The primary research question addressed is whether this novel diagnostic modality can safely and effectively aid the diagnosis of aseptic loosening.

METHODS

This clinical study included patients suspected of aseptic total knee arthroplasty (TKA) loosening listed for revision surgery and asymptomatic patients. Safety was evaluated using a numerical rating scale (NRS) for discomfort and by registration of adverse events. Feasibility was assessed by recording the duration and ease of the procedure. Intra- and interrater reliability were evaluated. In symptomatic patients, diagnostic accuracy metrics were evaluated with intra-operative assessment as a reference test.

RESULTS

In total, 34 symptomatic and 38 asymptomatic knees with a TKA were analysed. The median NRS for discomfort during loading was 6 (interquartile range [IQR]: 3.75-7.00) in symptomatic patients and 2 (IQR: 1.00-3.00) in asymptomatic patients. No adverse events were reported. The majority of users found the use of the loading device easy. The median time spent in the computed tomography room was 9 min (IQR: 8.00-11.00). Excellent to good intra- and interrater reliabilities were achieved. Diagnostic accuracy analysis resulted in a sensitivity of 0.91 (95% confidence interval [CI]: 0.72-0.97) and a specificity of 0.72 (95% CI: 0.43-0.90).

CONCLUSIONS

The proposed diagnostic method is safe, feasible, reliable and accurate in aiding the diagnosis of aseptic tibial component loosening.

LEVEL OF EVIDENCE

Level II.

Patient Frailty is Correlated With Increased Adverse Events and Costs After Revision Knee Arthroplasty

BACKGROUND

Frailty can predict adverse outcomes after various orthopaedic procedures, but is not well-studied in revision total knee arthroplasty (rTKA). We investigated the correlation between the Hospital Frailty Risk Score (HFRS) and post-rTKA outcomes.

METHODS

Using the Nationwide Readmissions Database, we identified rTKA patients discharged from January 2017 to November 2019 for the most common diagnoses (mechanical loosening, infection, and instability). Using HFRS, we compared 30-day readmission rate, length of stay, and hospitalization cost between frail and nonfrail patients with multivariate and binomial regressions. The 30-day complication and reoperation rates were compared using univariate analyses. We identified 25,177 mechanical loosening patients, 12,712 infection patients, and 9,458 instability patients.

RESULTS

Frail patients had higher rates of 30-day readmission (7.8 versus 3.7% for loosening, 13.5 versus 8.1% for infection, 8.7 versus 3.9% for instability; P < .01), longer length of stay (4.1 versus 2.4 days for loosening, 8.1 versus 4.4 days for infection, 4.9 versus 2.4 days for instability; P < .01), and greater cost ($32,082 versus $27,582 for loosening, $32,898 versus $28,115 for infection, $29,790 versus $24,164 for instability; P < .01). Frail loosening patients had higher 30-day complication (6.8 versus 2.9%, P < .01) and reoperation rates (1.8 versus 1.2%, P = .01). Frail infection patients had higher 30-day complication rates (14.0 versus 8.3%, P < .01). Frail instability patients had higher 30-day complication (8.0 versus 3.5%, P < .01) and reoperation rates (3.2 versus 1.6%, P < .01).

CONCLUSIONS

The HFRS may identify patients at risk for adverse events and increased costs after rTKA. Further research is needed to determine causation and mitigate complications and costs.

Mechanisms and Preventative Strategies for Persistent Pain following Knee and Hip Joint Replacement Surgery: A Narrative Review

Chronic postsurgical pain (CPSP) following total knee arthroplasty (TKA) and total hip arthroplasty (THA) is a prevalent complication of joint replacement surgery which has the potential to decrease patient satisfaction, increase financial burden, and lead to long-term disability. The identification of risk factors for CPSP following TKA and THA is challenging but essential for targeted preventative therapy. Recent meta-analyses and individual studies highlight associations between elevated state anxiety, depression scores, preoperative pain, diabetes, sleep disturbances, and various other factors with an increased risk of CPSP, with differences observed in prevalence between TKA and THA. While the etiology of CPSP is not fully understood, several factors such as chronic inflammation and preoperative central sensitization have been identified. Other potential mechanisms include genetic factors (e.g., catechol-O-methyltransferase (COMT) and potassium inwardly rectifying channel subfamily J member 6 (KCNJ6) genes), lipid markers, and psychological risk factors (anxiety and depression). With regards to therapeutics and prevention, multimodal pharmacological analgesia, emphasizing nonopioid analgesics like acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), has gained prominence over epidural analgesia. Nerve blocks and local infiltrative anesthesia have shown mixed results in preventing CPSP. Ketamine, an N-methyl-D-aspartate (NMDA)-receptor antagonist, exhibits antihyperalgesic properties, but its efficacy in reducing CPSP is inconclusive. Lidocaine, an amide-type local anesthetic, shows tentative positive effects on CPSP. Selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) have mixed results, while gabapentinoids, like gabapentin and pregabalin, present hopeful data but require further research, especially in the context of TKA and THA, to justify their use for CPSP prevention.

Effect of revision sacroiliac joint fusion on unresolved pain and disability: a retrospective cohort study

PURPOSE

The sacroiliac (SI) joint is recognized as a source of low back pain in 15-30% of patients. Though randomized controlled trials have shown clinical improvement following SI joint fusion in 83.1% of patients, revision rates of 2.9% within 2 years have been reported. There is a paucity of literature reviewing this small yet significant population of patients requiring revision surgery.

METHODS

Following IRB approval, retrospective review of patients, who underwent a revision SI joint fusion from 2009 to 2021 was completed. Patient-reported outcomes were measured before and at each clinic visit after surgery with visual analoge scale (VAS) for back pain and Oswestry Disability Index (ODI). Patient characteristics (chronic opiate use and prior lumbar fusion) and surgical factors (operative approach, type/number of implants and use of bone graft) were recorded. Patient-reported outcomes were evaluated with Paired t and Wilcoxon signed rank tests. Univariate and multivariate logistic regression determined if patients met the minimally clinical important differences (MCID) for VAS-back pain and ODI scores at 1 year.

RESULTS

Fifty-two patients (77% female) with an average age of 49.1 (SD ± 11.1) years met inclusion criteria. Forty-four had single sided revisions and eight bilateral revisions. At 1 year follow-up there was no significant improvement in VAS-Back (p = 0.06) or ODI (p = 0.06). Patients with chronic opioid use were 8.5 times less likely to achieve the MDC for ODI scores (OR 0.118, p = 0.029). There was no difference in outcomes when comparing the different surgical approaches (p = 0.41).

CONCLUSION

Our study demonstrates patients undergoing revision surgery have moderate improvement in low back pain, however, few have complete resolution of their symptoms. Specific patient factors, such as chronic opiate use and female sex may decrease the expected improvement in patient-reported outcomes following surgery. Failure to obtain relief may be due to incorrect indications, lack of biologic fusion and/or presence of co-pathologies. Further clinical examination and consistent long-term follow-up, clarify the role revision surgery plays in long-term patient outcomes.

The reimbursement system can influence the treatment choice and favor joint replacement versus other less invasive solutions in patients affected by osteoarthritis

PURPOSE

The aim of this study was to assess how physicians perceive the role of the reimbursement system and its potential influence in affecting their treatment choice in the management of patients affected by osteoarthritis (OA).

METHODS

A survey was administered to 283 members of SIAGASCOT (Italian Society of Arthroscopy, Knee, Upper Limb, Sport, Cartilage and Orthopaedic Technologies), a National scientific orthopaedic society. The survey presented multiple choice questions on the access allowed by the current Diagnosis-Related Groups (DRG) system to all necessary options to treat patients affected by OA and on the influence toward prosthetic solutions versus other less invasive options.

RESULTS

Almost 70% of the participants consider that the current DRG system does not allow access to all necessary options to best treat patients affected by OA. More than half of the participants thought that the current DRG system favors the choice of prosthetic solutions (55%) and that it can contribute to the increase in prosthetic implantation at the expense of less invasive solutions (54%). The sub-analyses based on different age groups, professional roles, and places of work allowed to evaluate the response in each specific category, confirming the findings for all investigated aspects.

CONCLUSIONS

This survey documented that the majority of physicians consider that the reimbursement system can influence the treatment choice when managing OA patients. The current DRG system was perceived as unbalanced in favor of the choice of the prosthetic solution, which could contribute to the increase in prosthetic implantation at the expense of other less invasive options for OA management.

Artificial Intelligence for Automated Implant Identification in Knee Arthroplasty: A Multicenter External Validation Study Exceeding 3.5 Million Plain Radiographs

BACKGROUND

Surgical management of complications following knee arthroplasty demands accurate and timely identification of implant manufacturer and model. Automated image processing using deep machine learning has been previously developed and internally validated; however, external validation is essential prior to scaling clinical implementation for generalizability.

METHODS

We trained, validated, and externally tested a deep learning system to classify knee arthroplasty systems as one of the 9 models from 4 manufacturers derived from 4,724 original, retrospectively collected anteroposterior plain knee radiographs across 3 academic referral centers. From these radiographs, 3,568 were used for training, 412 for validation, and 744 for external testing. Augmentation was applied to the training set (n = 3,568,000) to increase model robustness. Performance was determined by the area under the receiver operating characteristic curve, sensitivity, specificity, and accuracy. Implant identification processing speed was calculated. The training and testing sets were drawn from statistically different populations of implants (P < .001).

RESULTS

After 1,000 training epochs by the deep learning system, the system discriminated 9 implant models with a mean area under the receiver operating characteristic curve of 0.989, accuracy of 97.4%, sensitivity of 89.2%, and specificity of 99.0% in the external testing dataset of 744 anteroposterior radiographs. The software classified implants at a mean speed of 0.02 seconds per image.

CONCLUSION

An artificial intelligence-based software for identifying knee arthroplasty implants demonstrated excellent internal and external validation. Although continued surveillance is necessary with implant library expansion, this software represents a responsible and meaningful clinical application of artificial intelligence with immediate potential to globally scale and assist in preoperative planning prior to revision knee arthroplasty.

Patient-Reported Outcomes and Satisfaction 1 to 3 Years After Revisions of Total Knee Arthroplasties for Unexplained Pain Versus Aseptic Loosening

BACKGROUND

It is unknown if patients are relieved of pain after knee arthroplasty revision for unexplained pain. The aim of this cross-sectional case-control study was to compare patient-reported outcome measures (PROMs) and satisfaction 1 to 3 years after revision of total knee arthroplasties (TKAs) for the indications of unexplained pain versus aseptic loosening.

METHODS

We included 384 patients undergoing TKA revision for the indications of unexplained pain and aseptic loosening from January 1, 2018 to December 31, 2020 from the Danish Knee Arthroplasty Register. A total of 81 patients were revised for unexplained pain and 303 for aseptic loosening. Questionnaires including PROMs (Oxford Knee Score, EQ-5D-5L, and Forgotten Joint Score) and satisfaction with the surgery on a 0-100 scale (100 = not satisfied; 0 = very satisfied) were sent to digitally secured mailboxes. Time from revision to data collection was a median 3.1 years (range, 1.4-4.4 years).

RESULTS

Median Oxford Knee Score was 25 (interquartile range [IQR] 15) versus 31 (IQR 18) 1-3 years after revisions for unexplained pain versus aseptic loosening, P = .009. Median EQ-5D-5L was 0.6 (IQR 0.4) versus 0.8 (IQR 0.3) for unexplained pain versus aseptic loosening, P = .009. Median Forgotten Joint Score was 50 (IQR 7) versus 50 (IQR 16) for unexplained pain versus aseptic loosening, P = .905. Satisfaction was 75 (IQR 38) for unexplained pain and 50 (IQR 73) for aseptic loosening, P < .001.

CONCLUSION

Patients undergoing TKA revision for the indication of unexplained pain had worse results on PROMs than those revised for aseptic loosening. Likewise, patients revised for unexplained pain were less satisfied compared to patients revised for aseptic loosening. This information is valuable to both surgeons and patients when candidates for revision surgery are selected, to obtain the best possible outcomes.

Validation and Generalizability of Machine Learning Models for the Prediction of Discharge Disposition Following Revision Total Knee Arthroplasty

BACKGROUND

Postoperative discharge to facilities account for over 33% of the $ 2.7 billion revision total knee arthroplasty (TKA)-associated annual expenditures and are associated with increased complications when compared to home discharges. Prior studies predicting discharge disposition using advanced machine learning (ML) have been limited due to a lack of generalizability and validation. This study aimed to establish ML model generalizability by externally validating its prediction for nonhome discharge following revision TKA using national and institutional databases.

METHODS

The national and institutional cohorts comprised 52,533 and 1,628 patients, respectively, with 20.6 and 19.4% nonhome discharge rates. Five ML models were trained and internally validated (five-fold cross-validation) on a large national dataset. Subsequently, external validation was performed on our institutional dataset. Model performance was assessed using discrimination, calibration, and clinical utility. Global predictor importance plots and local surrogate models were used for interpretation.

RESULTS

The strongest predictors of nonhome discharge were patient age, body mass index, and surgical indication. The area under the receiver operating characteristic curve increased from internal to external validation and ranged between 0.77 and 0.79. Artificial neural network was the best predictive model for identifying patients at risk for nonhome discharge (area under the receiver operating characteristic curve = 0.78), and also the most accurate (calibration slope = 0.93, intercept = 0.02, and Brier score = 0.12).

CONCLUSION

All five ML models demonstrated good-to-excellent discrimination, calibration, and clinical utility on external validation, with artificial neural network being the best model for predicting discharge disposition following revision TKA. Our findings establish the generalizability of ML models developed using data from a national database. The integration of these predictive models into clinical workflow may assist in optimizing discharge planning, bed management, and cost containment associated with revision TKA.

Cruciate retaining total knee arthroplasty has a better 10 year survival than posterior stabilized total knee arthroplasty: a systematic review and meta-analysis

PURPOSE

There has been a long standing debate regarding superiority of cruciate retaining total knee arthroplasty over posterior stabilized total knee arthroplasty regarding the short-term outcomes as well as long-term survivorship. The proponents of both the techniques have published vast evidence in favor of their respective surgical method and early outcome in meta-analyses does not seem to be significantly different. The decision to select either design should depend on their long-term survivorship but the literature comparing their long-term survival is sparse.This meta-analysis was conducted in order to answer the following questions: (1) Does cruciate retaining total knee arthroplasty has a better long-term survival beyond 10 years.compared to posterior stabilized total knee arthroplasty? (2) Does cruciate retaining knee arthroplasty has higher complication rates compared to posterior stabilized total knee arthroplasty?

METHODS

The present systematic review and meta-analysis study was carried out following PRISMA guidelines. The following databases: Embase, Web of Science, PubMed, Scopus, the Cochrane Library, Google Scholar, and CINAHL were used to search potentially interesting articles published from database inception until January 2022. Inclusion criteria for articles were: (1) retrospective comparative studies; (2) patients who had undergone a total knee arthroplasty; (3) publications evaluating the long-term survival of cruciate-retaining (CR) versus posterior stabilizing (PS) at a minimum 10 years' follow-up; (4) publications evaluating complications of cruciate-retaining (CR) versus posterior stabilizing (PS) at a minimum 10 years' follow-up; and (5) publications reporting sufficient data regarding the outcomes. We used a fixed-effects design in the case of I² < 50% and P > 0.05; if not, we adopted a random-effects design [4]. We also performed subgroups and sensitivity analysis in order to assess the possible source of heterogeneity.

RESULTS

Database searching identified 597 studies to be screened, of which 291 abstracts were revealed as potentially eligible and finally 7 articles were included. The forest plot showed that CR had significantly better survival than PS (OR = 2.17; 95% CI: 1.69-2.80) after 10 years. However, complication rate was not significantly different between CR and PS groups (OR = 0.86; 95% CI: 0.52-1.44; P = 0.57). Subgroup analysis showed that only the period of publication constituted a source of heterogeneity in survivorship outcome. Sensitivity analysis revealed that outcomes did not differ markedly, which indicates that the meta-analysis had strong reliability.

CONCLUSION

The results of this meta-analysis showed that cruciate retaining prosthesis may be preferred over the posterior stabilized design in view of longer survivorship it offers However, further randomized controlled trials are recommended to confirm this finding.

The Impact of Hepatitis C on Complication Rates After Revision Total Knee Arthroplasty: A Matched Cohort Study

Background

It is unclear if hepatitis C (HCV) negatively impacts outcomes of revision total knee arthroplasty (rTKA). The purpose of this study was to compare complication rates after rTKA for patients with HCV vs matched controls.

Methods

A retrospective cohort study was conducted using the PearlDiver database (PearlDiver Inc., Colorado Springs, CO). Patients with HCV who underwent rTKA (n = 1448) were matched 1:4 with controls (n = 5792) on age, sex, and several comorbidities. Rates of medical complications within 90 days and prothesis-related complications within 2 years postoperatively were compared with logistic regression for (1) patients with vs without HCV and (2) HCV patients who underwent aseptic vs septic rTKA.

Results

Relative to controls, patients with HCV exhibited significantly higher rates of medical complications (27.7% vs 20.9%; odds ratio [OR] 1.47), periprosthetic fractures (2.3% vs 1.1%; OR 2.20), all-cause repeat rTKA (11.7% vs 9.4%; OR 1.29), and repeat rTKA for prosthetic joint infection (PJI) (6.7% vs 3.6%; OR 1.92). Within the HCV cohort, HCV patients with initial septic rTKA exhibited significantly higher rates of medical complications (41.7% vs 22.7%; OR 2.39), all-cause subsequent rTKA (15.9% vs 10.2%; OR 1.67), and repeat rTKA for PJI (15.9% vs 3.4%; OR 5.39). Conversely, HCV patients with initial aseptic rTKA exhibited significantly higher rates of aseptic loosening (2.6% vs 7.4%; OR 0.33).

Conclusions

Patients with HCV exhibited significantly higher rates of medical and prosthesis-related complications after rTKA than controls. Among patients with HCV, initial septic rTKA was associated with significantly higher rates of medical complications, repeat rTKA, and PJI.

The indication for aseptic revision TKA does not influence 1-year outcomes: an analysis of 178 full TKA revisions from a prospective institutional registry

BACKGROUND AND PURPOSE

Outcomes following revision total knee arthroplasty (TKA) may depend on the indication for revision surgery. We compared pain, patient-reported outcome measures (PROMs), and patient satisfaction among different indications for an aseptic TKA revision.

PATIENTS AND METHODS

This was a retrospective study of prospective data from an institutional registry of 178 primary TKAs revised between 2012 and 2020. Patients were grouped by the main reason for their revision: loosening, malposition, instability, or stiffness. Pain during mobilization and at rest (NRS 0-10), physical function (KOOS-PS and KSS), and quality of life (EQ-5D) were surveyed preoperatively and at 2 months and 1 year postoperatively. Patient satisfaction was evaluated through questions related to knee function and their willingness to undergo the same surgery again at 1-year follow-up.

RESULTS

Pain and PROMs improved in all groups and did not differ statistically significantly between the 4 groups at 1-year follow-up, but equivalence for pain was not confirmed between groups. Overall, pain during mobilization improved by 2.4 (95% CI 1.9-3.0) at 1-year follow-up, which was both clinically and statistically significant. Improvements were seen within 2 months of surgery, with no further improvements seen 1 year postoperatively. Approximately 2/3 of patients reported that their knee function had improved and would undergo the same surgery again, at 1-year follow-up.

CONCLUSION

Statistically significant and clinically relevant improvements in pain and PROMs were seen in all 4 revision groups 1 year after revision TKA. These results may assist clinicians and patients during preoperative counselling.