Total Knee Arthroplasty in the Elderly. Is There an Age Limit?

The goal of this study was to compare the results of the total knee arthroplasty (TKA) in 2 study groups only differing by age. We have analyzed 218 TKA cases (138 women and 80 men) with at least 2 years follow-up. Mean age was 70 years (SD, 7.38 years; range, 43 to 98 years). An age cutoff point at 75 years defined the 2 study groups: 167 cases younger than 75 years and 51 older. Results were evaluated using the Hospital for Special Surgery Score. Mean score was raised from 53.43 (SD, 9.186) preoperatively to 85.57 (SD, 10.763) in 2 years follow-up (P < .001). The final score did not show significant differences between both groups (86.11 for the younger group and 83.8 for the older group). Differences in pain on walking, pain at rest, walk, range of motion, climbing stairs, transfer, muscle strength, or instability were not found between the patients younger and older than 75 years. We did not find any differences in TKA, functional score, or pain between the 2 studied groups.     

Unicompartmental Versus Total Knee Arthroplasty Database Analysis: Is There a Winner?

Background  

TKA and unicompartmental knee arthroplasty (UKA) are both utilized to treat unicompartmental knee arthrosis. While some surgeons assume UKA provides better function than TKA, this assumption is based on greater final outcome scores rather than on change in scores and many patients with UKA have higher preoperative scores.     

Is There a Role for Preoperative Iron Supplementation in Patients Preparing for a Total Hip or Total Knee Arthroplasty?

Background

Several treatment modalities exist for the treatment of perioperative anemia. We determined the effect of oral iron supplementation on preoperative anemia, and the use of blood-conserving interventions before total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Success of Different Knee Arthrodesis Techniques After Failed Total Knee Arthroplasty: Is There a Preferred Technique?

Arthrodesis is a widely accepted treatment for failed total knee arthroplasty when further revision is contraindicated. In this study, we retrospectively review the pre-operative characteristics, operation techniques, treatment plans, and eventual outcomes in 42 consecutive patients (43 knees) who underwent knee arthrodesis at a single institution. Femorotibial fusion was achieved in 30 cases (75.0%). No cases of implant failure were recorded. Post-operative complications occurred in 20 cases (46.5%). Repeat arthrodesis was performed in 4 cases, and 2 patients eventually required above-the-knee amputation. Comparing the cases with successful vs. unsuccessful outcomes, there was a significant difference in days until hospital discharge following arthrodesis (P = .026), mean erythrocyte sedimentation rate prior to arthrodesis (P = .012), and the proportion of patients with post-operative wound complications (P = .021).     

How Flat Is the Tibial Osteotomy in Total Knee Arthroplasty?

BackgroundCementless total knee arthroplasty has been developed to decrease the incidence of failure in younger and more active patients. However, failures are still more common in cementless versus cemented components. It is hypothesized that this is triggered by incomplete bone-tray contact. The present study compares the final contact area of a cementless tray as a function of the initial osteotomy flatness.MethodsEight surgeons prepared 14 cadaveric knees for cementless total knee replacement using standard instrumentation. The topography of each osteotomy was captured with a laser scanner; 3-dimensional computer models of the surfaces were generated. After scanning each tibia, the surgeons implanted cementless tibial trays using a manual impactor. Each tibia was then dissected, embedded in mounting resin, and sectioned. The sectioned blocks were observed under stereomicroscopy to identify points of bone-tray contact which were incorporated into the 3-dimensional models. Maps were then generated illustrating depicting contacting and noncontacting areas.ResultsThe mean initial flatness of all specimens was 1.1 ± 0.35 mm. After impaction, 79.4% ± 0.3% of the surface had established bony contact. Of the noncontacting areas, 17.6% were within 0.3 mm of the tray. Only 2.6% of the surface was at distances reported to impede ingrowth. Noncontacting areas were typically located centrally. A trend in decreasing percent contact area with increased flatness tolerance was observed (R² = 0.605).Conclusion(1) There is an inverse correlation between the flatness of the tibial osteotomy and the percentage of the bony surface in contact with underside of the tibial tray. (2) Almost all tray-tibia contact is generated during implantation through flattening of elevated features on the tibial surface. (3) Gaps between the tray and the tibia are consistently located in the central regions of the osteotomy proximal to the medullary canal.     

Knee manipulation for reduced flexion after Total Knee Arthroplasty. Is timing critical?

Background

Reduced flexion following knee arthroplasty (TKA) may compromise patient’s function and outcome. The timing of manipulation under anaesthesia (MUA) has been controversial. We present our experience in a high volume practice and analyse the impact of timing.

How Accurate Is ICD-10 Coding for Revision Total Knee Arthroplasty?

BackgroundThe International Classification of Diseases-10 (ICD-10) came into effect in October 2015. The new procedural codes (ICD-10-PCS) were designed to specify granular aspects of the procedure, including laterality and revised components. This specificity could improve data collection in institutional databases, large registries, and administrative claims data. Given these possible applications, this study’s purpose was to assess the accuracy of ICD-10-PCS coding for revision total knee arthroplasty (rTKA).MethodsThis multicenter retrospective analysis utilized the rTKA databases at four academic medical centers for all aseptic rTKAs between October 1, 2015 and July 3, 2019. Operative reports were reviewed to determine laterality and revised components (tibial, femoral, liner, and patellar component), which were then compared with the ICD-10-PCS codes associated with the billing records. Proper coding required both component removal and replacement codes. The correct series of removal and replacement codes was determined using the American Joint Replacement Registry’s guidelines.ResultsIn total, 1906 rTKAs were examined, and 98.0% had at least one proper ICD-10-PCS code, indicating an rTKA had occurred. Coding for components replaced was correct in 76.3% of cases. When examining both removal and replacement codes, accuracy dropped to 57.0%.ConclusionNearly 25% of rTKA procedures were incorrectly coded for replaced components, and over 40% were incorrectly coded for removed and replaced components. ICD-10-PCS codes can accurately identify that an rTKA has occurred; however, the inaccuracy in identifying which specific components were revised should prompt further evaluation of the coding process before utilizing ICD-10-PCS codes to report granular rTKA data.Level of EvidenceIII, retrospective observational analysis.     

Is the New Outpatient Prospective Payment System Classification for Outpatient Total Knee Arthroplasty Appropriate?

BackgroundIn 2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the inpatient-only list, resulting in payment through the Outpatient Prospective Payment System with an average $3157 reduction. The purpose of this study is to determine if the reimbursement is justified by comparing the difference in facility costs between inpatient and outpatient TKAs.MethodsWe identified 4496 consecutive primary TKA procedures performed at 2 hospitals from 2015 to 2019. Itemized facility costs were calculated using a time-driven activity-based costing algorithm. Outpatient procedures were defined as those with a length of stay of less than 2 midnights (3851, 86%). Patient demographics, comorbidities, and itemized costs were compared between groups. A multivariate regression analysis was performed to determine the independent effect of outpatient status on true facility costs.ResultsOutpatient TKA patients had lower mean postoperative personnel costs ($1809 vs $947, P < .001), supply costs ($4347 vs $4229, P < .001), and overall total facility costs ($7371 vs $6937, P < .001) than inpatient TKA patients. Controlling for a younger patient cohort with fewer medical comorbidities, outpatient status was associated with a reduction in total facility costs of $972 (95% confidence interval $883-$1060, P < .001) compared to inpatient TKA.ConclusionOutpatient TKA costs hospitals nearly $1000 per patient less than inpatient TKA, yet the average difference in Medicare reimbursement for an outpatient procedure is $3157 less per patient. Centers for Medicare and Medicaid Services should reconsider the Outpatient Prospective Payment System classification of TKA to better incentivize surgeons to perform TKA as a lower cost outpatient procedure when safe and appropriate.     

Computer-Assisted Total Knee Arthroplasty: Is There a Difference Between Image-Based and Imageless Techniques?

Background

Image-based and imageless computer-assisted total knee arthroplasty (CATKA) has become increasingly popular. This study aims to compare outcomes, including perioperative complications and transfusion rate, between CATKA and conventional total knee arthroplasty (TKA), as well as between image-based and imageless CATKA.

Is Pseudo-Patella Baja Really a Serious Complication of Total Knee Arthroplasty?

BackgroundThe available evidence on pseudo-patella baja (PPB) is limited. The purpose of this study is to investigate prospectively the occurrence of PPB after primary total knee arthroplasty and its clinical consequences in a large series of patients with a minimum follow-up of 2 years. PPB was defined as a patella distally displaced in relationship to the femoral trochlea with absence of patellar tendon shortening (Grelsamer RP. J Arthroplasty 2002;17:66-69) due to elevation of the joint line.MethodsThis study is a prospective case series of 354 patients with a mean age of 71.7 (range 52-87) years. Clinical evaluation was performed by the Knee Society Scores (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short-Form 12-item (SF12), and range of motion. Patellar height was assessed by the Insall-Salvati and Blackburne-Peel ratios.ResultsThe mean follow-up was 3.6 (range 2.0-6.6) years. Postoperatively, 286 (80.7%) patients had a normal patellar height, 17 (4.8%) had true patella baja (TPB), and 51 (14.4%) had PPB. There were no significant differences between the 3 groups in mean KSS-function (P = .107), range of motion (P = .408), WOMAC-pain (P = .095), WOMAC-stiffness (P = .279), or SF12-mental (P = .363). Between normal and PPB groups, there were no significant differences in mean KSS-knee (P = .903), WOMAC-function (P = .294), or SF12-physical (P = .940). However, the TPB group had significantly lower mean KSS-knee (P = .031), WOMAC-function (P = .018), and SF12-physical (P = .005) as compared with either 2 other groups.ConclusionPPB was a relatively common finding, but no significant differences in terms of clinical outcomes were found as compared to patients with postoperative normal patellar height. TPB was infrequent, but these patients had significantly worse clinical outcomes than those with PPB or normal patellar height.     

Is Unicompartmental Arthroplasty an Acceptable Option for Spontaneous Osteonecrosis of the Knee?

Background  

The literature suggests survivorship of unicompartmental knee arthroplasties (UKAs) for spontaneous osteonecrosis of the knee ranges from 93% to 97% at 10 to 12 years. However, these data arise from small series (23 to 33 patients), jeopardizing meaningful conclusions.     

Is There a Place for Rotating-Hinge Arthroplasty in Knee Revision Surgery for Aseptic Loosening?

We reviewed the results of 78 revision total knee arthroplasties using a rotating-hinge device, performed from 1993 through 2002. The average follow-up was 7.83 years. Only patients requiring revision arthroplasty due to aseptic loosening were included. Reasons for revision were malalignment with or without polyethylene wear (47), instability (24), extensor mechanism failure (3), and periprosthetic fracture (4). The mean preoperative scores according to the American Knee Society rating scale was 37.5 points for knee score and 32.8 points for function score. Postoperatively, the knee score improved to 85.7 points and the function score improved to 61.4 points. Nineteen patients had complications related to the design prostheses (mostly minor complications). Fifty-seven patients (73%) had excellent results, with a range of motion of 104 degrees in flexion and complete extension. For extreme circumstances, such as gross instability of the medial collateral ligament, massive bone loss, comminuted fracture, and chronic dysfunction of the extensor mechanism, there is a place for hinged revision implant surgery with good clinical results and quality of life.     

Are There Prognostic Factors for One-Year Outcome After Total Knee Arthroplasty? A Systematic Review

Background

Preoperative factors predicting outcome for pain, physical function and quality of life after total knee arthroplasty (TKA) have not been clearly identified.

Revision of Unicompartmental to Total Knee Arthroplasty: Does the Unicompartmental Implant (Metal-Backed vs All-Polyethylene) Impact the Total Knee Arthroplasty?

Background

The aim of this study is to investigate differences in implant requirement, outcomes, and re-revision when total knee arthroplasty (TKA) was performed following unicompartmental knee arthroplasties (UKAs) with metal-backed (MB) compared to all-polyethylene (AP) tibial components.