Heterotopic Ossification Prophylaxis After Total Hip Arthroplasty: Randomized Trial of 400 vs 700 cGy.

Background: Heterotopic ossification (HO) is a known complication following total hip arthroplasty. Radiation is an effective prophylaxis, but an optimal protocol has yet to be determined. We performed a randomized, double-blinded clinical trial in high-risk patients to determine the efficacy of 400 vs 700 cGy doses of radiation.

ADAMTS5 is required for biomechanically-stimulated healing of murine tendinopathy.

A recently developed murine model of tendinopathy, induced by TGF-β1 injection, has been used to examine the reparative capacity of tendinopathic Achilles in Adamts5(-/-) mice. After TGF-β1 injection and 2 weeks of treadmill exercise, the Achilles from Adamts5(-/-) mice exhibited a reduction in maximum tensile stress of approximately 60%. However, in contrast to wild type mice previously characterized by this model, Adamts5(-/-) mice subjected to further treadmill exercise were unable to reverse this biomechanical deficit.

Ten-year outcome of serum metal ion levels after primary total hip arthroplasty: a concise follow-up of a previous report*.

We previously reported on the metal ion concentrations of cobalt, chromium, and titanium that were found in the serum of patients three years after they had undergone primary total hip arthroplasty as compared with the concentrations found in the serum of control patients who did not have an implant. This study is a concise update on the serum metal levels found in a cohort of these patients ten years after the time of hip implantation. Of the original seventy-five subjects, metal ion levels were available for forty patients (53%).

Successful long-term fixation and progression of osteolysis associated with first-generation cementless acetabular components retrieved post mortem.

Background: Primary cementless acetabular reconstruction has shown durable long-term fixation. Late failures secondary to aseptic loosening are rare but may occur in patients with previously well-fixed components. In the present study, the histopathological characteristics of postmortem specimens were correlated with wear damage and radiographic data in an attempt to better understand the long-term events in the periacetabular tissue around well-functioning devices.

Long-term survivorship and failure modes of unicompartmental knee arthroplasty.

Background: In a previously reported series of 51 patients with 62 cemented, fixed-bearing unicompartmental knee arthroplasties, we reported a 10-year, 98% survival rate with an average knee score of 92 points. The survivorship and modes of failure past 10 years are incompletely understood.

Questions/purposes: At 15-year followup we sought to determine (1) the overall durability and survivorship of this design; (2) modes of failure; and (3) the progression of arthritis in the nonresurfaced compartments.

Surface damage versus tibial polyethylene insert conformity: a retrieval study.

Background: Surface damage of the tibial polyethylene insert in TKA is thought to diminish with increasing conformity, based on computed lower contact stresses. Added constraint from higher conformity may, however, result in greater forces in vivo.

Questions/purposes: We therefore determined whether increased conformity was associated with increased surface pitting, delamination, creep, and polishing in a group of retrieved tibial inserts.

Posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis: a concise follow-up of a previous report.

7We previously reported the minimum eight-year follow-up results of cruciate-retaining total knee arthroplasty in a consecutive series of seventy-two knees in patients with rheumatoid arthritis. In the present study, we evaluated the longer-term outcomes after twenty to twenty-five years of follow-up. Since the publication of our original study, ten knees have been revised: three because of periprosthetic fracture, three because of infection, two because of patellofemoral failure, and two because of posterior instability.

Murine tendon function is adversely affected by aggrecan accumulation due to the knockout of ADAMTS5.

The present study examined the effect of ADAMTS5 (TS5) knockout on the properties of murine flexor digitorum longus (FDL) and Achilles tendons. FDL and Achilles tendons were analyzed using biomechanical testing, histology, and immunohistochemistry; further characterization of FDL tendons was conducted using transmission electron microscopy (collagen fibril ultrastructure), SDS-PAGE (collagen content and type), fluorescence-assisted carbohydrate electrophoresis for chondroitin sulfate and hyaluronan, and Western blotting for aggrecan, versican, and decorin abundance and distribution. FDL tendons of TS5(-/-) mice showed a 33% larger cross-sectional area, increased collagen fibril area fraction, and decreased material properties relative to those of wild type mice.

Biochemical identification and immunolocalizaton of aggrecan, ADAMTS5 and inter-alpha-trypsin-inhibitor in equine degenerative suspensory ligament desmitis.

We describe analysis of suspensory ligaments from horses with advanced degenerative suspensory ligament desmitis (DSLD) to identify the major proteoglycans (PGs), ADAMTS-aggrecanases and inter-alpha-trypsin inhibitor (IαI) components associated with ligament degeneration. Specific anatomical regions of suspensory ligaments from two normal horses and four diagnosed with DSLD were analyzed by Western blot and immunohistochemistry for the following: aggrecan, aggrecan fragments, decorin, ADAMTS4, ADAMTS5, and IαI components. When compared to normal, DSLD ligaments showed about a 15-fold increase (P < 0.

Cruciate-retaining TKA using a third-generation system with a four-pegged tibial component: a minimum 10-year followup note.

Background: A third-generation TKA system was designed to address problems encountered with earlier designs including a high rate of patellofemoral complications. At a minimum of 5 years, we previously reported survivorship of 98.7% using revision for any reason as the endpoint for a cohort that includes the patients described in this report.

Primary total hip arthroplasty with a porous-coated acetabular component. A concise follow-up, at a minimum of twenty years, of previous reports.

We previously reported the seven and fifteen-year results of the use of a porous-coated acetabular metal shell inserted without cement in a consecutive series of 204 primary total hip arthroplasties. In the present study, we evaluated the longer-term outcomes of these arthroplasties at a minimum follow-up time of twenty years. One hundred and fourteen (92%) of the 124 hips available for study had retained the original acetabular metal shell.

Revision of the acetabulum with a contemporary cementless component.

We evaluated the performance of a contemporary cementless acetabular component at a minimum of 5 years postoperatively. One hundred eighty-seven consecutive acetabular component revisions were performed using a hemispherical porous-coated component. Patients were followed prospectively with radiographs and Harris hip scores.

Revision of the acetabular component without cement. A concise follow-up, at twenty to twenty-four years, of a previous report.

We previously reported the results of the use of a cementless acetabular shell for revision total hip arthroplasty in 138 hips at a minimum of three, seven, and fifteen years postoperatively. The current report presents the long-term outcomes of this group at a minimum follow-up of twenty years. Since the last report, two additional hips required repeat revision, both for infection; no additional acetabular shell was loose.

How have alternative bearings (such as metal-on-metal, highly cross-linked polyethylene, and ceramic-on-ceramic) affected the prevention and treatment of osteolysis?

Osteolysis is a multifactorial process dependent on surgical technique, implant design, patient factors, and material composition. Alternative bearing surfaces, such as highly cross-linked polyethylene, ceramic-on-ceramic, and metal-on-metal articular surfaces, have been introduced in an attempt to reduce wear and osteolysis following total hip arthroplasty. Intermediate-term follow-up data available suggest that the prevalence and severity of osteolysis may be reduced with these materials compared with conventional metal-on-polyethylene bearing surface couples.

Role of fibroblasts and fibroblast-derived growth factors in periprosthetic angiogenesis.

The periprosthetic granulomatous soft tissue [designated iterfacial membrane (IFM) in this study] exhibits heterogeneous histopathological features, in which highly vascularized areas with dense cellularity alternate with fibrotic and pseudocapsule-like tissue structures. Although macrophage/monocyte activation is a prominent event in the periprosthetic environment, fibroblasts also phagocytose particulate wear debris both in vivo and in vitro. Particulate wear debris and/or cytokines/growth factors alone or in combination (e.

Revision of the acetabular component without cement after total hip arthroplasty. A concise follow-up, at fifteen to nineteen years, of a previous report.

We previously reported our results at a minimum of three and seven years after use of a porous-coated acetabular metal shell in a consecutive series of 138 revision total hip arthroplasties. The current report presents the longer-term outcomes of these procedures, at fifteen to nineteen years postoperatively. A total of twenty metal shells (14%) underwent repeat revision.

Results of unicompartmental knee arthroplasty at a minimum of ten years of follow-up.

Background: There is a renewed interest in unicompartmental knee arthroplasty. The present report describes the minimum ten-year results associated with a unicompartmental knee arthroplasty design that is in current use.

Methods: Sixty-two consecutive unicompartmental knee arthroplasties that were performed with cemented modular Miller-Galante implants in fifty-one patients were studied prospectively both clinically and radiographically.

Implant survivorship and complication rates after total knee arthroplasty with a third-generation cemented system: 5 to 8 years followup.

Unlabelled: We evaluated implant survivorship, reoperation rates, and complication rates of a group of patients who had total knee arthroplasty with a third-generation cemented prosthetic device using cruciate-retaining and posterior-stabilized designs at 5 to 8 years followup. Three hundred thirty-four consecutive primary total knee arthroplasties (186 cruciate retaining and 148 posterior stabilized) were done in 287 patients at our institution during a 2-year period. Kaplan Meier survivorship using revision for any reason and revision for aseptic loosening as endpoints were 95.

The progression of patellofemoral arthrosis after medial unicompartmental replacement: results at 11 to 15 years.

This study reports the 11-year to 15-year results of unicompartmental knee arthroplasty with an emphasis on failure mechanisms and progression of patellofemoral arthrosis. In a prospective study of 513 consecutive potential knee replacement candidates, 59 patients (12%) had medial unicompartmental arthroplasty of the knee. All 59 patients had isolated unicompartmental disease without clinical symptoms or radiographic evidence of patellofemoral arthritis.

Primary total hip arthroplasty with a porous-coated acetabular component. A concise follow-up of a previous report.

We previously reported the seven-to-ten-year results of the use of a porous-coated acetabular metal shell in a consecutive series of 204 primary total hip arthroplasties. In the present study, we evaluated the longer-term outcomes of these arthroplasties, at fifteen to eighteen years. One hundred and thirty-six (96%) of the 142 hips available for study retained the original acetabular metal shell.