Highly Crosslinked-remelted versus Less-crosslinked Polyethylene in Posterior Cruciate-retaining TKAs in the Same Patients

Background

Concern regarding osteolysis attributable to polyethylene wear after TKA, particularly in younger patients, has prompted the introduction of highly crosslinked-remelted polyethylene (HXLPE) for TKAs. However, few in vivo comparative results of TKAs using HXLPE and less-crosslinked polyethylene inserts in the same patients are available, regarding fracture or failure of the locking mechanism of tibial polyethylene inserts or of osteolysis in patients younger than 60 years.

Questions/Purposes

We wanted to determine whether (1) survivorship free from aseptic loosening in knees with HXLPE inserts was different from survivorship in knees with less-crosslinked polyethylene inserts, (2) the prevalence of fracture or failure of the locking mechanism of the tibial polyethylene insert was greater in knees with HXLPE than in those with less-crosslinked polyethylene, and (3) the proportion of patients who had osteolysis develop was greater with HXLPE than with less-crosslinked polyethylene inserts.

Methods

One hundred seventy-one patients with a mean age of 58 ± 8 years (range, 35−59 years) received posterior cruciate-retaining prostheses with a less-crosslinked polyethylene tibial insert in one knee and a HXLPE tibial insert in the contralateral knee. From January 2007 to January 2010, we performed 366 same-day bilateral simultaneous sequential posterior cruciate-retaining TKAs in 183 patients, of whom 171 (93%) participated in this study. All patients during this study period underwent posterior cruciate-retaining TKAs regardless of deformity of the knees and we did not perform posterior-stabilized TKAs during the same period. Patients who had bilateral end-stage osteoarthritis and were younger than 60 years were selected for inclusion. Six patients (4%) were lost to followup before 5 years. Twenty-six patients were males and 145 were females. The mean duration of followup was 6 years (range, 5−8 years). At each followup, patients were assessed for loosening of the components, fracture or failure of the locking mechanism of the polyethylene inserts, or osteolysis.

Results

The survival rate of the knee prosthesis at a mean of 5.8 years after surgery was 100% (95% CI, 0.95–1.00) in both groups for the endpoint aseptic loosening and 99.4% (95% CI, 0.95–1.00) in both groups for the endpoint revision. No knee in either group had fracture or failure of the locking mechanism of the tibial polyethylene insert, and none had osteolysis.

Conclusions

With the numbers available, we found no clinically important differences between HXLPE and less-crosslinked polyethylene inserts in posterior cruciate-retaining TKAs. Given that HXLPE is newer, as-yet unproven, and more expensive than the proven technology (less-crosslinked polyethylene), we suggest not adopting HXLPE for clinical use until it shows superiority.

Level of Evidence

Level I, therapeutic study.     

Wear Damage in Mobile-bearing TKA is as Severe as That in Fixed-bearing TKA

Background  

Mobile-bearing TKAs reportedly have no clinical superiority over fixed-bearing TKAs, but a potential benefit is improved polyethylene wear behavior.     

A Monoblock Porous Tantalum Acetabular Cup Has No Osteolysis on CT at 10 Years

Background  

Aseptic osteolysis has been the single most important factor limiting the longevity of a THA. A great deal of attention has been focused on the development of implants and materials that minimize the development of osteolysis. The monoblock porous tantalum acetabular cup was designed to minimize osteolysis, but whether it does so is unclear.     

Treatment Based on the Type of Infected TKA Improves Infection Control

Background  

A classification system with four types of infected TKAs has been commonly used to determine treatment, especially with regard to whether the prosthesis should be removed or retained.     

Screw Track Osteolysis in the Cementless Total Knee Replacement Design

Background

There is a paucity of reports on osteolysis associated with tibial screw fixation in cementless total knee arthroplasty (TKA), and the pathophysiology is not clear. This study aimed to describe the pathology related to screw track osteolysis around the tibia in cementless TKA.

Cementless and cemented total knee arthroplasty in patients younger than fifty five years. Which is better?

Purpose

The purpose of this prospective, randomised study was to evaluate long-term clinical results, radiographic findings, complications and revision and survivorship rates in patients <55 years at a minimum of 16 years after undergoing bilateral, sequential, simultaneous, cemented and cementless total knee arthroplasties (TKAs) in the same patients.

Methods

Bilateral, sequential, simultaneous TKAs were performed in 80 patients (160 knees). There were 63 women and 17 men with a mean age of 54.3 years (range 49–55), who received a cementless prosthesis in one knee and a cemented prosthesis in the other. The mean follow-up was 16.6 years (range 16–17).

Results

At final review, the mean Knee Society (KS) knee scores (95.8 versus 96.9), Western Ontario and McMaster Universities (WOMAC) osteoarthritis (OA) index (25.4 versus 25.9), range of motion (ROM) (125°versus 128°), patient satisfaction (8.1 versus 8.3) and radiological results were similar in both groups. Femoral component survival rate was 100 % in both groups at 17 years; at 17 years, the cemented tibial component survival rate was 100 % and the cementless tibial component 98.7 %. No osteolysis was identified in either group.

Conclusion

Long-term results of both cementless and cemented TKAs were encouraging in patients with OA who were <55 years. However, we found no evidence to prove the superiority of cementless over cemented TKAs.     

Early Reactive Synovitis and Osteolysis after Total Hip Arthroplasty

Background  

Little is known about intraarticular pathology following THA prior to the radiographic appearance of osteolysis, primarily due to imaging limitations. MRI has recently been applied to imaging the postarthroplasty hip with the ability to detect periarticular bony and soft tissue pathology; specifically, it is able to detect abnormal synovial patterns and focal bone loss well before the radiographic appearance of osteolysis.     

What Are the Causes of Revision Total Knee Arthroplasty in Japan?

Background

There is limited information regarding the cause of revision TKA in Asia, especially Japan. Owing to differences in patient backgrounds and lifestyles, the modes of TKA failures in Asia may differ from those in Western countries.

Questions/purposes

We therefore determined (1) causes of revision TKA in a cohort of Japanese patients with revision TKA and (2) whether patient demographic features and underlying diagnosis of primary TKA are associated with the causes of revision TKA.

Methods

We assessed all revision TKA procedures performed at five major centers in Hokkaido from 2006 to 2011 for the causes of failures. Demographic data and underlying diagnosis for index primary TKA of the revision cases were compared to those of randomly selected primary TKAs during the same period.

Results

One hundred forty revision TKAs and 4047 primary TKAs were performed at the five centers, indicating a revision burden of 3.3%. The most common cause of revision TKA was mechanical loosening (40%) followed by infection (24%), wear/osteolysis (9%), instability (9%), implant failure (6%), periprosthetic fracture (4%), and other reasons (8%). The mean age of patients with periprosthetic fracture was older (77 versus 72 years) and the male proportion in patients with infection was higher (33% versus 19%) than those of patients in the primary TKA group. There was no difference in BMI between primary TKAs and any type of revision TKA except other causes.

Conclusions

The revision burden at the five referral centers in Hokkaido was 3.3%, and the most common cause of revision TKA was mechanical loosening followed by infection. Demographic data such as age and sex might be associated with particular causes of revision TKA.     

Highly Crosslinked Polyethylene Reduces Wear in Total Hip Arthroplasty at 5 Years

Background  

Although hip arthroplasty reliably relieves pain and improves function, problems have arisen with wear and osteolysis. Highly crosslinked polyethylene has been developed to address this problem although at present there is limited clinical evidence it does so longer term.     

Alumina Heads Minimize Wear and Femoral Osteolysis Progression After Isolated Simple Acetabular Revision

Background  

Patients with THA requiring cup revision for acetabular osteolysis may have a stable stem component without loosening. However, it is unclear whether isolated cup revision halts femoral osteolysis progression.     

Comparison of Modular Conventional and High-Flexion Posterior-Stabilized Total Knee Arthroplasties in the Same Patients at a Mean Follow-Up of 15 Years

BackgroundAs previous studies are limited to short-term clinical data on conventional and high-flexion total knee arthroplasties (TKAs), long-term clinical data on these TKAs remain unclear. Therefore, we evaluated long-term functional outcome, range of knee motion, revision rate, implant survival, and the prevalence of osteolysis after conventional and high-flexion TKAs in the same patients.MethodsThe authors evaluated a cohort of 1206 patients with a mean age of 65.3 ± 7 years (range: 22-70) who underwent bilateral simultaneous sequential TKAs. One knee received a conventional TKA and the other received a high-flexion TKA. The mean duration of follow-up was 15.6 years (range: 14-17).ResultsNo significant differences were found between the 2 groups at the latest follow-up with respect to Knee Society score (93 vs 92 points, P = .765), pain score (45 vs 44 points, P = .641), range of knee motion (125° vs 126°, P = .712), and radiographic and computed tomography scan results. Furthermore, no significant revision rate differences were found between the 2 groups (1.3% for conventional TKA vs 1.6% for high-flexion TKA; P = .137). There was no osteolysis recorded in either group. The rate of survivorship free of implant revision or aseptic loosening was 98.7% (95% CI = 91-100) for conventional TKA and 98.4% (95% CI = 91-100) for high-flexion TKA at 17 years.ConclusionAt the latest follow-up, we were not able to demonstrate any significant difference between conventional and high-flexion TKAs with respect to functional outcome scores, range of knee motion, revision rate, implant survival, and prevalence of osteolysis.     

Race may not affect [correct] outcomes in operatively treated tibia fractures

Background  

A recent review of the literature found worse outcomes and longer length of stay for minorities undergoing TKAs and THAs when compared with whites. It is unclear if this association exists for the operative treatment of tibia fractures.     

All-Polyethylene Tibial Components in Obese Patients Are Associated With Low Failure at Midterm Followup

Background  

In the United States, the obese population has increased markedly over the last four decades, and this trend continues. High patient weight places additional stress on TKA components, which may lead to increased polyethylene wear, osteolysis, radiolucencies, and clinical failure. Metal-backed tibial components and all-polyethylene tibial components in the general population have comparable osteolysis and failure, but it is unclear whether these components yield similar osteolysis and failure in obese patients.     

Does a Modified Gap-balancing Technique Result in Medial-pivot Knee Kinematics in Cruciate-retaining Total Knee Arthroplasty?: A Pilot Study

Background  

Normal knee kinematics is characterized by posterior femorotibial rollback with tibial internal rotation and medial-pivot rotation in flexion. Cruciate-retaining TKAs (CR-TKAs) do not reproduce normal knee kinematics.     

Ceramic-on-Ceramic Total Hip Arthroplasty: Incidence of Instability and Noise

Background  

Alternative bearing materials in THA have been developed to reduce the incidence of osteolysis. Alumina-on-alumina bearings exhibit extremely low wear rates in vitro, but concerns exist regarding component impingement with the potential for dislocation and the occurrence of noise.     

Rotational References for Total Knee Arthroplasty Tibial Components Change with Level of Resection

Background  

Various landmarks can guide tibial component rotational alignment in routine TKA, but with the deeper tibial resection levels common in complex primary and revision TKAs, it is unknown whether these landmarks remain reliable.     

Complete acetabular cup revision versus isolated liner exchange for polyethylene wear and osteolysis without loosening in cementless total hip arthroplasty

Introduction  

Revision surgery in patients showing polyethylene wear and acetabular osteolysis without visible acetabular cup loosening involves the difficult decision of whether to revise only the liner or both the cup and the liner. The purpose of this study is to compare the outcomes of complete acetabular revision and isolated liner exchange in patients showing wear and osteolysis without loosening.     

Osteolysis after rotator cuff repair with bioabsorbable anchors

Purpose  

The current study was designed to evaluate the rate of osteolysis and the clinical and functional outcomes in patients who underwent mini-open rotator cuff repairs using first generation bioabsorbable suture anchors. Our hypothesis was that patients with osteolysis noted on post-repair MRI would have an accompanying decrease in functional and clinical patient outcomes when compared with patients who did not have osteolysis evident on post-repair MRI.     

Liner Exchange and Bone Grafting: Rare Option to Treat Wear & Lysis of Stable TKAs

Background  

Liner exchange and bone grafting are commonly performed for wear and osteolysis around well-fixed modular acetabular components that otherwise would require structural allografting and revision THA. However, liner exchange in the face of substantial lysis around TKA has been performed rarely with reports of failure rates of up to 25% at 3 year followup.