Femoral Component Debonding Frequently Missed on Advanced Imaging Prior to Revision of a Recalled Total Knee Arthroplasty

BACKGROUND

Identification of femoral component debonding in the work-up of painful total knee arthroplasty (TKA) often poses a diagnostic challenge. The purpose of this study was to compare the sensitivity and specificity of radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) for identifying femoral component loosening with debonding at the time of revision of a primary TKA with a recalled polyethylene insert.

METHODS

Using an institutional database, we identified all cases of revision TKA performed for this specific implant recall following a primary TKA between 2014 and 2022. Patients who had a preoperative radiograph, CT, and MRI were included (n = 77). Sensitivity, specificity, and positive and negative likelihood ratio (LR) for predicting loosening were compared among the imaging modalities, using the intraoperative evidence of implant loosening as the gold standard.

RESULTS

At the time of revision surgery, the femoral component was noted to have aseptic loosening with debonding in 46 of the 77 (60%) of the TKAs. There were no significant differences in demographics in the cohort with femoral debonding compared to those with well-fixed implants. The CT demonstrated a sensitivity of 28% and a specificity of 97%, while the MRI demonstrated a sensitivity of 37% and a specificity of 94% for detecting femoral loosening due to debonding. Both CT and MRI demonstrated poor negative LRs for femoral loosening (LR 0.7).

CONCLUSIONS

In this series of revision TKAs for a specific recalled component, neither CT nor MRI accurately diagnosed femoral component debonding. For patients who have this implant, it is imperative to interrogate the implant-cement interface intraoperatively and prepare for full revision surgery as well as marked bone loss secondary to osteolysis.

Is Tibial Bone Mineral Density Related to Sex, Age, Preoperative Alignment, or Fixation Method in Primary Total Knee Arthroplasty?

BACKGROUND

Cementless total knee arthroplasty (TKA) has regained interest for its potential for long-term biologic fixation. The density of the bone is related to its ability to resist static and cyclic loading and can affect long-term implant fixation; however, little is known about the density distribution of periarticular bone in TKA patients. Thus, we sought to characterize the bone mineral density (BMD) of the proximal tibia in TKA patients.

METHODS

We included 42 women and 50 men (mean age 63 years, range: 50 to 87; mean body mass index 31.6, range: 20.5 to 49.1) who underwent robotic-assisted TKA and had preoperative computed tomography scans with a BMD calibration phantom. Using the robotic surgical plan, we computed the BMD distribution at 1 mm-spaced cross-sections parallel to the tibial cut from 2 mm above the cut to 10 mm below. The BMD was analyzed with respect to patient sex, age, preoperative alignment, and type of fixation.

RESULTS

The BMD decreased from proximal to distal. The greatest changes occurred within ± 2 mm of the tibial cut. Age did not affect BMD for men; however, women between 60 and 70 years had higher BMD than women ≥ 70 years for the total cut (P = .03) and the medial half of the cut (P = .03). Cemented implants were used in 1 86-year-old man and 18 women (seven < 60 years, seven 60 to 70 years, and four ≥ 70 year old). We found only BMD differences between cemented or cementless fixation for women < 60 years.

CONCLUSIONS

To our knowledge, this is the first study to characterize the preoperative BMD distribution in TKA patients relative to the intraoperative tibial cut. Our results indicate that while sex and age may be useful surrogates of BMD, the clinically relevant thresholds for cementless knees remain unclear, offering an area for future studies.

Joint Replacement Technology in the Ambulatory Surgery Center: Current and Future Applications

Total joint replacement (TJR) surgery in the ambulatory surgery centers (ASCs) has grown significantly over the past several years, along with the ability to improve the value of care. Standardization of high-quality, perioperative care is pivotal to the success of a TJR ASC program. As surgeons are experiencing increasing overhead with decreasing reimbursement, technology integration can provide major advantages. In this article, we will therefore highlight several examples of technologies that are changing the field and improving care in the preoperative, intraoperative, and postoperative settings.

The Efficacy and Safety of Tranexamic Acid in Total Hip and Knee Arthroplasty: A Literature Review

Historically, total hip arthroplasty (THA) and total knee arthroplasty (TKA) have been associated with significant perioperative blood loss and a relatively high rate of allogeneic blood transfusions. However, in recent years, tranexamic acid (TXA), a competitive inhibitor of tissue plasminogen activator, inhibiting fibrinolysis of existing thrombi, has substantially decreased the need for blood transfusion in THA and TKA. Various administration strategies have been studied, but there remains a lack of consensus on an optimal route and dosing regimen, with intravenous and topical regimens being widely used. A growing body of literature has demonstrated the safety and efficacy of TXA in primary and revision THA and TKA to reduce blood loss, allogeneic transfusions, and complications; it is associated with lowered lengths of stay, costs, and readmission rates.

Correcting Hip Dysplasia in Young Adults: Intraoperative Navigation and Outcomes

Developmental dysplasia of the hip (DDH) often leads to characteristic acetabular dysplasia and typical femoral anomalies. There are numerous treatments for skeletally mature patients with DDH including hip arthroscopy, pelvic and femoral osteotomies, as well as total hip arthroplasty. Before proceeding to an arthroplasty procedure, it can be helpful to obtain an opinion of a hip preservation specialist to ascertain if alternative surgical treatments could contribute to the patient's care. In general, the use of robotic navigation has been associated with a higher proportion of cups placed in the Lewinnek safe zone, larger improvements in Harris Hip Scores, and no difference in overall complication rates in comparison to manual total hip arthroplasty. The use of robotic navigation allows for both 2-dimensional and 3-dimensional preoperative templating, enabling the surgeon to plan the position of the construct such that it achieves maximum bony purchase and hip stability. In complex DDH cases, surgeons can work with a biomechanics department to complete a fit check assessment, which utilizes 3-dimensional templating software to ascertain the appropriateness of the implant's geometry with the patient's anatomy. Furthermore, a 3-dimensional printed plastic model of the pelvis and/or femur can be constructed in order to complete a rehearsal procedure, which may be particularly helpful for those cases involving osteotomies. The literature on the use of robotic-assisted total hip arthroplasty in patients with DDH demonstrates improved component positioning in comparison to navigated as well as manual methods; however, studies with long-term follow-up in this patient population are lacking.

Total Hip Arthroplasty: An Update on Navigation, Robotics, and Contemporary Advancements

While total hip arthroplasty (THA) remains effective for improvement of pain and function in patients with osteoarthritis and avascular necrosis, there remain areas of continued pursuit of excellence, including decreasing rates of dislocation, leg length discrepancy, implant loosening, and infection. This review article covers several bearing surfaces and articulations, computer-assisted navigation and robotic technology, and minimally invasive surgical approaches that have sought to improve such outcomes. Perhaps the most significant improvement to THA implant longevity has been the broad adoption of highly cross-linked polyethylene, with low wear rates. Similarly, navigation and robotic technology has proven to more reproducibly achieve intraoperative component positioning, which has demonstrated clinical benefit with decreased risk of dislocation in a number of studies. Given the projected increase in THA over the coming decades, continued investigation of effective incorporation of technology, soft tissue-sparing approaches, and durable implants is imperative to continued pursuit of improved outcomes in THA.

Referencing the center of the femoral head during robotic or computer-navigated primary total knee arthroplasty results in less femoral component flexion than the traditional intramedullary axis

BACKGROUND

During robotic and computer-navigated primary total knee arthroplasty (TKA), the center of the femoral head is utilized as the proximal reference point for femoral component position rather than the intramedullary axis. We sought to analyze the effect on femoral component flexion-extension position between these two reference points.

METHODS

We obtained CT 3D-reconstructions of 50 cadaveric intact femurs. We defined the navigation axis as the line from center of the femoral head to center of the knee (lowest point of the trochlear groove) and the intramedullary axis as the line from center of the knee to center of the canal at the isthmus. Differences between these axes in the sagittal plane were measured. Degree of femoral bow and femoral neck anteversion were correlated with the differences between the two femoral axes.

RESULTS

On average, the navigated axis was 1.4° (range, -1.4° to 4.1°) posterior to the intramedullary axis. As such, the femoral component would have on average 1.4° less flexion compared with techniques referencing the intramedullary canal. A more anterior intramedullary compared with navigated axis (i.e., less femoral flexion) was associated with more femoral bow (R2 = 0.7, P < 0.001) and less femoral neck anteversion (R2 = 0.5, P < 0.05).

CONCLUSION

Computer-navigated or robotic TKA in which the center of the femoral head is utilized as a reference point, results in 1.4° less femoral component flexion than would be achieved by referencing the intramedullary canal. Surgeons should be aware of these differences as they may ultimately influence knee kinematics.

Does Time to Reimplantation After Explant for Prosthetic Joint Infection Influence the Likelihood of Successful Outcomes at 2 Years?

BACKGROUND

Consensus recommendations are lacking regarding appropriate timing of reimplantation following 2-stage resection arthroplasty for prosthetic joint infections (PJIs). We investigated whether the time from resection arthroplasty to reimplantation was associated with treatment outcome at 2 years.

METHODS

Retrospective cohort review was conducted for 101 patients undergoing resection arthroplasty with an antibiotic spacer for PJI at a single tertiary academic referral institution. Time from explantation and spacer placement to reimplantation was categorized into 3 groups: <12, 12-18, and >18 weeks. Baseline patient and treatment course characteristics across these groups were obtained. Multivariate binary logistic regression was used to characterize association between treatment failure and time to reimplantation, controlling for American Society of Anesthesiologists (ASA) score and prior revision surgery.

RESULTS

Time to reimplantation (TTR) >18 weeks demonstrated statistically significant increased odds of treatment failure, after controlling for ASA score and prior revision surgery (odds ratio 7.00, confidence interval 2.14-25.42, P = .002). After excluding patients requiring second spacer or Girdlestone prior to replant, this increased odds of failure remained (odds ratio 4.12, confidence interval 1.18-15.37, P = .029). TTR groups were similar with respect to demographics, except for ASA (2.96 for time to reimplantation >18 weeks vs 2.55 for time to reimplantation <12 weeks; P = .011). Patients with TTR >18 weeks were more likely to have an unplanned readmission during the spacer period (48%, 19%, and 6% for time to reimplantation >18, 12-18, and 0-12 weeks, respectively; P < .002).

CONCLUSION

Although decision regarding TTR is largely patient specific, surgeons should be aware that TTR >18 weeks may be associated with higher rates of treatment failure at 2 years.

Does Hospital Teaching Status Matter? Impact of Hospital Teaching Status on Pattern and Incidence of 90-day Readmissions After Primary Total Hip Arthroplasty

Background

Given financial and clinical implications of readmissions after total hip arthroplasty (THA) and the potential for varied expenditures related to a hospital’s teaching status, this study sought to characterize 90-day hospital readmission patterns and assess likelihood of readmission based on teaching designation of a Medicare beneficiaries’ (MB’s) index THA hospital.

Methods

Retrospective analysis of 2016-2018 Centers for Medicare and Medicaid Services-linked data identified primary THA hospitalizations and readmissions within 90 days. Hospitals were categorized as teaching or nonteaching (Council of Teaching Hospitals and Health Systems). Chi-squared analysis and Fisher exact test assessed differences between readmission hospitals and the index hospital teaching status. Multivariate logistic regression models estimated risk-adjusted probability of experiencing at least one 90-day readmission.

Results

Analysis identified 433,959 index THA admissions with an all-cause 90-day readmission rate of 9.12%. Most readmissions were to the same hospital regardless of index THA hospital teaching status (67.5% index teaching; 68.2% index nonteaching). Crossover in hospital teaching status from the index procedure to readmission location was more common for those with index THA at a teaching hospital (18.9%) than for MBs with index THA performed at a nonteaching hospital (6.2%). Controlling for patient characteristics, no significant relationship was found between 90-day readmission and index hospital teaching status (odds ratio 0.98, confidence interval 0.947–1.011).

Conclusions

Overall, while certain patterns of readmission after the index THA were observed, after controlling for patient characters and comorbidities, there was no significant association between 90-day all-cause readmission and index hospital teaching status.

Does Preoperative Opioid Consumption Increase the Risk of Chronic Postoperative Opioid Use After Total Joint Arthroplasty?

Background

Risk-factor identification related to chronic opioid use after surgery may facilitate interventions mitigating postoperative opioid consumption. We evaluated the relationship between opioid use preceding total hip arthroplasty (THA) and total knee arthroplasty (TKA), and chronic use postoperatively, and the risk of chronic opioid use after total joint arthroplasty.

Methods

All primary THAs and TKAs performed during a 6-month period were identified. Opioid prescription and utilization data (in oxycodone equivalents) were determined via survey and electronic records. Relationship between preoperative opioid use and continued use >90 days after surgery was assessed via Chi-square, with significance set at P < .05.

Results

A total of 415 patients met inclusion criteria (240 THAs and 175 TKAs). Of the 240 THAs, 199 (82.9%) patients and of the 175 TKAs, 144 (82.3%) patients agreed to participate. Forty-three of 199 (21.6%) THA patients and 22 of 144 (15.3%) TKA patients used opioids within 30 days preoperatively. Nine of 199 (4.5%) THA and 10 of 144 (6.9%) TKA patients had continued use of opioids for >90 days postoperatively. Preoperative opioid consumption was significantly associated with chronic use postoperatively for THA (P = .011) and TKA (P = .024). Five of 43 (11.6%) THA and 4 of 22 (18.2%) TKA patients with preoperative opioid use had continued use for >90 days postoperatively. For opioid naïve patients, 2.6% (4/156) of THA and 4.9% (6/122) of TKA patients had chronic use postoperatively.

Conclusions

Preoperative opioid use was associated with nearly 5-fold and 4-fold increase in percentage of patients with chronic opioid use after THA and TKA, respectively. Surgeons should counsel patients regarding this risk and consider strategies to eliminate preoperative opioid use.

Is the Proportion of Patients with "Successful" Outcomes After Two-stage Revision for Prosthetic Joint Infection Different When Applying the Musculoskeletal Infection Society Outcome Reporting Tool Compared with the Delphi-based Consensus Criteria?

BACKGROUND

There are a variety of criteria for defining successful treatment after two-stage exchange arthroplasty for prosthetic joint infection (PJI). To accurately assess current practices and improve techniques, it is important to first establish reliable, clinically relevant, reproducible criteria for defining persistent infection and "successful" outcomes.

QUESTION/PURPOSE

Is the proportion of patients considered to have successful management of PJI after two-stage resection arthroplasty smaller using 2019 Musculoskeletal Infection Society Outcome Reporting Tool (MSIS ORT) criteria than when using a Delphi-based criterion?

METHODS

Patients were retrospectively identified by Current Procedural Technology codes for resection arthroplasty with placement of an antibiotic spacer for infected THA or TKA between April 1, 2011 and January 1, 2018 at a tertiary academic institution. The initial review identified 180 procedures during this time period. Nine patients had documented transition of care outside the system, 16 did not meet the MSIS criteria for chronic PJI, and 34 patients were excluded for lack of documented 2-year follow-up. The mean follow-up duration of the final cohort of 121 procedures in 120 patients was approximately 3.7 ± 1.7 years. Forty percent (49 of 121) of the procedures were performed on the hip and 60% (72 of 121) were performed on the knee. The mean time from primary THA or TKA to explantation was 4.6 years. The mean age of the patients at the time of explantation was 66 years. The mean time from spacer placement to replantation was 119 days. The final 121 patient records were reviewed by a single reviewer and outcomes were subsequently assigned to "successful" and "unsuccessful" outcomes based on the MSIS ORT and Delphi-based consensus criterion, two previously published and validated multidimensional definition schemes. Chi-squared and t-test analyses were performed to identify differences between "successful" and "unsuccessful" outcomes with respect to patient baseline characteristics using each outcome-reporting criterion.

RESULTS

Overall, the MSIS ORT classified a smaller proportion of patients as having a "successful" treatment outcome after two-stage exchange arthroplasty for PJI than the Delphi-based consensus method did (MSIS: 55% [63 of 114], Delphi: 70% [71 of 102]; relative risk 0.79 [0.65-0.98]; p = 0.03). However, there were no differences when stratified by hips (MSIS: 55% [26 of 47], Delphi: 74% [29 of 39]; relative risk 0.74 [0.54-1.02]; p = 0.07) and knees (MSIS: 55% [37 of 67], Delphi: 67% [42 of 63]; relative risk 0.83 [0.63-1.09]; p = 0.19). Notably, the disease of 16% of the patients (19 of 121) was not classifiable per the Delphi method because these patients never underwent reimplantation.

CONCLUSION

The present study demonstrated that the MSIS criteria detect fewer instances of "successful" infection management after two-stage resection arthroplasty for PJI than the Delphi method in this cohort. Based on these findings, researchers and surgeons should aim for standardized reporting after intervention for PJI to allow for a better comparison of outcomes across different studies and ultimately allow for improved techniques and approaches to the treatment of PJI.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Patient-Reported Allergies, a Marker of Preoperative Pain and Disability in Elective Spine Surgery

STUDY DESIGN

Retrospective review.

OBJECTIVE

Previous literature demonstrates mixed results regarding the relationship between patient-reported allergies and pain, function, and satisfaction scores. The objective of this study was to investigate the correlation between patient-reported allergies and preoperative Oswestry Disability Index (ODI), Neck Disability Index (NDI), and Patient-Reported Outcomes Measurement System (PROMIS) scores.

METHODS

All patients undergoing elective cervical, lumbar procedures between May 2017 and October 2018 were included. Baseline demographic information was recorded, as well as all reported allergies or adverse reactions. Preoperative PROMIS, ODI, and NDI scores were recorded. Hierarchical multiple linear regressions were used to assess the relationship between total number of allergies and the preoperative pain and function scores.

RESULTS

A total of 570 patients were included (476 lumbar, 94 cervical). The mean number of allergies reported was 1.89 ± 2.32. The mean preoperative ODI and NDI scores were 46.39 ± 17.67 and 43.47 ± 16.51, respectively. The mean preoperative PROMIS Physical Health and PROMIS Mental Health scores were 37.21 ± 6.54 and 43.89 ± 9.26, respectively. Hierarchical multiple linear regression showed that total number of reported allergies shared a statistically significant negative relationship with all of the following scores: ODI (B = 0.83, P = .02), NDI (B = 1.45, P = .02), PROMIS Physical Health (B = -0.29, P = .013), and PROMIS Mental Health (B = -0.38, P = .024).

CONCLUSIONS

Patient-reported allergies share a statistically significant negative relationship with preoperative pain and function scores; as patients have increasing total number of allergies, the ODI/NDI scores become worse (increase) and the PROMIS scores become worse (decrease).