What can be learned from minimum 20-year followup studies of knee arthroplasty?

Background: Long-term evaluation of knee arthroplasty should provide relevant information concerning the durability and performance of the implant and the procedure. Because most arthroplasties are performed in older patients, most long-term followup studies have been performed in elderly cohorts and have had low patient survivorship to final followup; the degree to which attrition from patient deaths over time in these studies might influence their results has been poorly characterized.

Questions/purposes: The purpose of this study was to examine the results at 20-year followup of two prospectively followed knee arthroplasty cohorts to determine the following: (1) Are there relevant differences among the two implant cohorts in terms of revision for aseptic causes (osteolysis, or loosening)? (2) How does patient death over the long followup interval influence the comparison, and do the comparisons remain valid despite the high attrition rates?

Methods: Two knee arthroplasty cohorts from a single orthopaedic practice were evaluated: a modular tibial tray (101 knees) and a rotating platform (119 knees) design.

Total hip arthroplasty surgical approach does not alter postoperative gait mechanics one year after surgery.

Objective: To investigate the differences in gait biomechanics on the basis of surgical approach 1 year after surgery.

Design: This was a descriptive laboratory study to investigate the side-to-side differences in walking mechanics at a self-selected walking speed as well as a functional assessment 1 year after total hip arthroplasty (THA). Temporospatial, kinetic, and kinematic data as well as functional outcomes were collected.

Does surgical approach during total hip arthroplasty alter gait recovery during the first year following surgery?

Multiple surgical approaches exist for total hip arthroplasty (THA). Each approach has risks and benefits in regard to complications and changes in postoperative gait. This study examined the effect of three surgical approaches on postoperative gait mechanics.

Durability of a cruciate-retaining TKA with modular tibial trays at 20 years.

Background: Modular tibial trays have been utilized in TKA for more than 20 years. However, concerns have been raised about modular implants and it is unclear whether these devices are durable in the long term.

Questions/purposes: We determined (1) survival, (2) relationship of age and polyethylene thickness with revision, (3) function, and (4) radiographic lucencies and osteolysis in patients having a single TKA implant at 20-year followup.

Response of Chondrocytes to Local Mechanical Injury in an Ex Vivo Model.

Background: Our goal was to set up an ex vivo culture system to assess whether cartilage wounding (partial-thickness defects) can induce morphological changes in neighboring chondrocytes and whether these cells can translocate to the surface of the defect.

Methods: Two-millimeter partial-depth defects were created in human osteochondral explants followed by culture for up to 4 weeks. Frozen sections of defects and defect-free regions were labeled using immunofluorescence for a plasma membrane protein, CD44, and actin with TRITC-phalloidin.

The Rottinger approach for total hip arthroplasty: technique and review of the literature.

The surgical approach utilized in total hip arthroplasty has been identified as a factor that may affect surgical outcomes. There have been many different approaches and modifications used since the procedure was popularized by Sir John Charnley. The popular approaches today can be grouped by their relationship to the trochanter (anterior or posterior), patient position, leg position for dislocation/femoral preparation, and treatment of the abductors and short external rotators.

The effect of total hip arthroplasty surgical approach on postoperative gait mechanics.

Surgical approach for total hip arthroplasty (THA) is determined by clinician preference from limited prospective data. This study aimed to examine the effect of surgical approach (direct lateral, posterior, and anterolateral) on 6-week postoperative gait mechanics. Thirty-five patients (direct lateral, 8; posterior, 12; anterolateral, 15) were tested preoperatively and 6 weeks after THA.

Routine surveillance of modular PFC TKA shows increasing failures after 10 years.

Background/rationale: A 10-year survivorship of 100% was reported for patients with PFC cruciate-retaining prostheses. Beyond 10 years, we observed additional polyethylene wear likely related to thin liners gamma-irradiated in air and were concerned this wear might predispose to implant construct failure.

Questions/purposes: We therefore determined (1) the functional scores at a minimum of 15 years followup, (2) rates of radiographic failure, (3) overall revision rates, and (4) mode of failure after 10 years and the fate of the revised implants.

Activity scale for arthroplasty patients after total hip arthroplasty.

The purpose of the Activity Scale for Arthroplasty Patients (ASAP) is to develop and validate a self-report questionnaire that demonstrated discrimination of functional gains, low burden, appropriate concurrent validity, and was not limited by ceiling effects. We identified 128 high-functioning hip arthroplasty patients from our database who completed a 25-item ASAP and Lower Extremity Functional Scale questionnaires and a set of anchor questions. Factor analysis identified 10 items associated with 2 distinct factors: (1) activities and (2) running and running-related environments.

Survival of polished compared with precoated roughened cemented femoral components. A prospective, randomized study.

Background: The optimal surface finish for cemented femoral components remains controversial. The purpose of this randomized clinical trial was to compare the survival of two femoral components with similar geometry but substantially different surface finishes.

Methods: During a five-year period, 201 patients (219 hips) were prospectively randomized to be treated with a total hip arthroplasty with either a polished (Ra, 0.

Characterization of a consistent radiographic finding in chronic anterior cruciate ligament deficiency: the posteromedial osteophyte.

Often found in patients undergoing total knee arthroplasty (TKA) is an osteophyte, at the posterior lateral corner of the medial tibial plateau, that prevents anterior translation. This osteophyte does not occur in the presence of an entirely normal anterior cruciate ligament (ACL) with normal vascularity. Although similar findings have been reported in animal studies, to our knowledge this has never been documented in humans.

The use of constrained components in total hip arthroplasty.

The use of a constrained component may be appropriate for the surgical treatment of recurrent dislocation due to soft-tissue insufficiency following a total hip arthroplasty. Constrained components usually include a locking mechanism incorporated into the polyethylene acetabular liner to keep the prosthetic femoral head in place. Two different prosthetic designs are available and have been approved by the U.

Hip arthroplasty after extracapsular hip fracture: a matched pair cohort analysis.

Eighteen patients with a prior intertrochanteric or basicervical hip fracture had a total or bipolar hip arthroplasty. The clinical and radiographic results of these patients were compared to a control group of patients (matched for age, gender, associated diagnoses, and length of follow-up) who had a primary total hip arthroplasty. There was a significant increase in intraoperative blood loss, operative time, and number of units of blood transfused in the fracture group compared to the primary arthroplasty group.

Cementation for femoral head osteonecrosis: a preliminary clinic study.

Treatment for femoral head osteonecrosis has been less successful in late stages of the disease, after progression to collapse. The current authors treated 21 patients (22 hips) with Stage III osteonecrosis by a technique of open reduction and fixation with methylmethacrylate cement (cementation). The followup ranged from 1 to 3 years (average, 1.

Role of pericellular matrix in development of a mechanically functional neocartilage.

The role of the chondrocyte pericellular matrix (PCM) was examined in a three-dimensional chondrocyte culture system to determine whether retention of the native pericellular matrix could stimulate collagen and proteoglycan accumulation and also promote the formation of a mechanically functional hyaline-like neocartilage. Porcine chondrocytes and chondrons, consisting of the chondrocyte with its intact pericellular matrix, were maintained in pellet culture for up to 12 weeks. Sulfated glycosaminoclycans and type II collagen were measured biochemically.

Posterior cruciate-retaining modular total knee arthroplasty: a 9- to 12-year follow-up investigation.

Between November 1988 and January 1991, 101 press-fit condylar (PFC; Johnson & Johnson, Raynham, MA) posterior cruciate-retaining total knee arthroplasties were performed in 75 patients. All tibial components were modular metal-backed, and all patellar components were all-polyethylene. All living patients were evaluated at an average 10.

Retention of the native chondrocyte pericellular matrix results in significantly improved matrix production.

The interaction of the cell with its surrounding extracellular matrix (ECM) has a major effect on cell metabolism. We have previously shown that chondrons, chondrocytes with their in vivo-formed pericellular matrix, can be enzymatically isolated from articular cartilage. To study the effect of the native chondrocyte pericellular matrix on ECM production and assembly, chondrons were compared with chondrocytes isolated without any pericellular matrix.

Development of selective tolerance to interleukin-1beta by human chondrocytes in vitro.

Interleukin-1 induces release of NO and PGE(2) and production of matrix degrading enzymes in chondrocytes. In osteoarthritis (OA), IL-1 continually, or episodically, acts on chondrocytes in a paracrine and autocrine manner. Human chondrocytes in chondron pellet culture were treated chronically (up to 14 days) with IL-1beta.

Collar versus collarless cemented HD-II femoral prostheses.

A randomized prospective study was done in 1982 to evaluate the effect of a collar on the cemented femoral component. During a 2-year period, 84 patients were enrolled to receive a collared (44 hips) or a collarless (40 hips) HD-II femoral component at the time of their primary total hip arthroplasty. Three patients were lost to followup, two patients were excluded because of randomization errors, six patients had good clinical results but refused followup, and 30 patients had died.