Biomedical subjects

Joshua J Jacobs

Publications and source records attributed to Joshua J Jacobs.

At least 37 records · Page 2Linked to original sources

PubMed2005

Outpatient total knee arthroplasty with a minimally invasive technique.

Fifty consecutive patients were enrolled in this prospective study. This was 37% of the 135 patients undergoing primary total knee arthroplasty (TKA) by one surgeon. The average patient age was 68 years (50-79 years). A comprehensive perioperative management pathway was developed and was implemented, which combined regional anesthesia with a minimally invasive, TKA technique in which the only incision in the capsule and extensor mechanism is a capsular incision from the joint line to the superior pole of the patella. Postoperatively, patients received oral analgesia. After specific discharge criteria were met, 48 patients (96%) chose to go home the day of surgery. No intraoperative complications occurred. There were 3 readmissions, none related to early discharge: gastrointestinal bleed at 8 days, superficial irrigation and debridement at 21 days, and a closed manipulation at 9 weeks. This study demonstrates that, in these selected patients, outpatient TKA was safe with no short-term readmission or complications related to early discharge. This comprehensive pathway may make it possible for this minimally invasive TKA to be done as an outpatient in specialized surgicenters in the future.

Aged↗

PubMed2005

Lymphocyte responses in patients with total hip arthroplasty.

How lymphocyte-mediated metal sensitivity affects orthopaedic implant performance remains poorly understood. Do patients with implants exhibit elevated lymphocyte reactivity to metals and is this reactivity more generalized or more implant-alloy specific? We investigated these questions by measuring lymphocyte responses to implant metals (Cr(+3), Co(+2), Ni(+2) at 0.1mM, and Ti(+4) at 0.001 mM) in six subject groups: Group 1a=young controls, Group 1b=age matched controls, Group 2a=subjects with osteoarthritis (OA) and no history of metal sensitivity, Group 2b=OA subjects with history of metal sensitivity, Group 3a=total hip arthroplasty (THA) subjects with no to mild radiographic osteolysis, and Group 3b=THA subjects with moderate osteolysis. Lymphocyte proliferation, using Lymphocyte Transformation Testing (LTT), and cytokine release provided quantitative reactivity measurement, where a stimulation index of >2 indicated metal sensitivity. OA subjects with a history of metal sensitivity (Group 2b) were more metal reactive to Ni than any other group, as expected (66% incidence and Stimulation Index >20). However, THA subjects (Groups 3a and b) were >3 fold more reactive to Cr (p<0.04), than were controls (Groups 1a & b) or OA subjects (Groups 2a & b). THA subjects with moderate vs mild osteolysis (Group 3b vs 3a) were more reactive to Co (43% vs 0% incidence). Only osteolytic THA subjects demonstrated increased cytokine responses with >two-fold (p<0.05) increases in soluble interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) levels in response to Cr challenge. This elevated incidence and averaged level of lymphocyte reactivity supports a metal-specific adaptive immune response and suggests involvement in the pathogenesis of poor implant performance, e.g. aseptic osteolysis.

Adult↗

PubMed2005

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. All patients had isolated unicompartmental disease without patellofemoral symptoms. No patient was lost to follow-up. Thirteen patients (thirteen knees) died after less than ten years of follow-up, leaving thirty-eight patients (forty-nine knees) with a minimum of ten years of follow-up. The average duration of follow-up was twelve years. RESULTS: The mean Hospital for Special Surgery knee score improved from 55 points preoperatively to 92 points at the time of the final follow-up. Thirty-nine knees (80%) had an excellent result, six (12%) had a good result, and four (8%) had a fair result. At the time of the final follow-up, thirty-nine knees (80%) had flexion to at least 120 degrees . Two patients (two knees) with well-fixed components underwent revision to total knee arthroplasty, at seven and eleven years, because of progression of patellofemoral arthritis. At the time of the final follow-up, no component was loose radiographically and there was no evidence of periprosthetic osteolysis. Radiographic evidence of progressive loss of joint space was observed in the opposite compartment of nine knees (18%) and in the patellofemoral space of seven knees (14%). Kaplan-Meier analysis revealed a survival rate of 98.0% +/- 2.0% at ten years and of 95.7% +/- 4.3% at thirteen years, with revision or radiographic loosening as the end point. The survival rate was 100% at thirteen years with aseptic loosening as the end point. CONCLUSIONS: After a minimum duration of follow-up of ten years, this cemented modular unicompartmental knee design was associated with excellent clinical and radiographic results. Although the ten-year survival rate was excellent, radiographic signs of progression of osteoarthritis in the other compartments continued at a slow rate. With appropriate indications and technique, this unicompartmental knee design can yield excellent results into the beginning of the second decade of use.

Aged↗

PubMed2005

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. Seven of the repeat revisions were performed because of recurrent dislocation, seven were done at the time of femoral revision surgery, and six were done because of infection. Nineteen of the revised shells were well fixed, and one was aseptically loose. Of the sixty-seven hips in which the acetabular component survived for more than fifteen years after the index operation, two (3%) required a change of the modular acetabular liner because of wear or osteolysis. Nine (16%) of the fifty-seven hips with at least fifteen years of radiographic follow-up had an osteolytic lesion of >1 cm in diameter. The fifteen-year survival rate of the metal shells, with failure defined as revision because of loosening or as radiographic evidence of loosening, was 97%. Revision total hip arthroplasty with this cementless acetabular component has been followed by excellent component survivorship at fifteen years; the most common reasons for repeat revision were recurrent dislocation and infection.

Acetabulum↗

PubMed2005

The relationship between activity and ions in patients with metal-on-metal bearing hip prostheses.

BACKGROUND: Total hip replacements with metal-on-metal bearings are frequently implanted in young, active patients. The relationship between patient activity and cobalt and chromium ion levels has not been investigated, to our knowledge. METHODS: Seven patients with well-functioning metal-on-metal bearing hip prostheses and one control subject (no implants), all with normal renal function, were monitored during a two-week-long activity protocol. Lower-extremity activity was continuously assessed with use of a computerized, two-dimensional accelerometer. During the first week, the subjects were requested to limit physical activity. The subjects then completed an hour-long treadmill test followed by a week in which they were encouraged to be as physically active as practically possible. Serum levels of cobalt and chromium ions and urine levels of chromium were assessed at ten time-points during these two weeks. RESULTS: Regardless of activity, the serum ion levels for a given patient were essentially constant and no correlation was found between patient activity and serum levels of cobalt or chromium, or urine levels of chromium. A mean increase in activity of 28% during the week of high-intensity activity was associated with a mean decrease of 2.7% in the serum cobalt level and a mean increase of 2.0% in the serum chromium level. During the treadmill test, a mean increase in activity of 1621% was associated with a mean increase of 3.0% in the serum cobalt level and a mean increase of 0.8% in the serum chromium level. These results fall within the variability for the measurement accuracy of these tests. CONCLUSIONS: For these patients, serum cobalt and chromium ion levels were not acutely affected by patient activity. Periodic measurements of serum ion levels could be used to monitor the tribologic (lubrication, friction, and wear) performance of a metal-on-metal bearing without adjusting for patient activity. Additional research is needed into the kinetics of ion production, transport, and excretion.

Adult↗

PubMed2005

Extensor mechanism allograft reconstruction after total knee arthroplasty.

BACKGROUND: Disruption of the extensor mechanism is an uncommon but catastrophic complication of total knee arthroplasty. We evaluated two techniques of reconstructing a disrupted extensor mechanism with the use of an extensor mechanism allograft in revision total knee arthroplasty. METHODS: Twenty consecutive reconstructions with the use of an extensor mechanism allograft consisting of the tibial tubercle, patellar tendon, patella, and quadriceps tendon were performed. The first seven reconstructions (Group I) were done with the allograft minimally tensioned. The thirteen subsequent procedures (Group II) were performed with the allograft tightly tensioned in full extension. All surviving allografts were evaluated clinically and radiographically after a minimum duration of follow-up of twenty-four months. RESULTS: All of the reconstructions in Group I were clinical failures, with an average postoperative extensor lag of 59 degrees (range, 40 degrees to 80 degrees ) and an average postoperative Hospital for Special Surgery knee score of 52 points. All thirteen reconstructions in Group II were clinical successes, with an average postoperative extensor lag of 4.3 degrees (range, 0 degrees to 15 degrees ) (p < 0.0001) and an average Hospital for Special Surgery score of 88 points. Postoperative flexion did not differ significantly between Group I (average, 108 degrees ) and Group II (average, 104 degrees ) (p = 0.549). CONCLUSIONS: The results of reconstruction with an extensor mechanism allograft after total knee arthroplasty depend on the initial tensioning of the allograft. Loosely tensioned allografts result in a persistent extension lag and clinical failure. Allografts that are tightly tensioned in full extension can restore active knee extension and result in clinical success. On the basis of the number of knees that we studied, there was no significant loss of flexion. Use of an extensor mechanism graft for the treatment of a failure of the extensor mechanism will be successful only if the graft is initially tensioned tightly in full extension.

Arthroplasty, Replacement, Knee↗

PubMed2005

The biology of alternative bearing surfaces in total joint arthroplasty.

Periprosthetic osteolysis is currently the dominant limiting factor in joint arthroplasty longevity. Because this process is predominantly a biologic response to particulate wear debris and/or corrosion products, alternative bearing surfaces and highly cross-linked polyethylenes have been developed in an attempt to reduce the incidence of wear-induced periprosthetic osteolysis. These alternative bearing surfaces currently include ceramic-on-polyethylene, ceramic-on-ceramic, metal-on-metal, and metal or ceramic on highly cross-linked polyethylene. Although these alternative bearings diminish the generation of polyethylene debris, metallic or ceramic debris is produced. In addition, the biologic response to debris generated from alternate bearings is not fully elucidated and is related not only to particle number, but also to particle size, shape, composition, and surface area.

Arthroplasty, Replacement↗

PubMed2004

A consensus paper on metal ions in metal-on-metal hip arthroplasties.

The number of metal-on-metal bearings used clinically continues to increase, particularly in young, active patients. The single greatest concern with the use of a metal-on-metal bearing continues to be the elevated levels of metal ions measurable in patients' blood and urine following implantation. There are multiple complex issues associated with the analysis of metal ions, including collection techniques, analysis, statistical methodologies, and reporting of results. To date, the literature on this topic has been characterized by significant variability in all of these factors. This paper seeks to establish a consensus among 3 investigators who have been working in this area and to offer guidelines on the complex methodology involved in the evaluation of metal concentration in patients following metal-on-metal hip arthroplasties.

Hip Prosthesis↗

PubMed2004

Immune responses correlate with serum-metal in metal-on-metal hip arthroplasty.

Cell-mediated hypersensitivity associated with metal components may be related to levels of implant debris. We tested this hypothesis by comparing lymphocyte reactivity to soluble Co, Cr, Ni, and Ti of patients with metal-on-polyethylene and metal-on-metal arthroplasties with healthy controls, and patients with osteoarthritis. The metal-on-metal group (n=9) demonstrated significantly elevated serum Co and Cr concentrations (13- and 58-fold, P<.05, respectively) and significantly elevated lymphocyte reactivity to Co (SI>5, P<.004) and Ni (SI>2.5, P<.01) when compared to controls (n=12) and subjects with metal-on-poly implants (n=7). These elevated in vivo metal levels demonstrated positive linear correlation with lymphocyte reactivity supporting our hypothesis that lymphocyte metal-induced reactivity increases with increased metal exposure. These results represent the first direct link between in vivo metal exposure and lymphocyte reactivity. Whether this lymphocyte reactivity to metal debris is etiologically linked to poor implant performance remains uncertain.

Aged↗

PubMed2004

Accumulation in liver and spleen of metal particles generated at nonbearing surfaces in hip arthroplasty.

Systemic migration of metal particles generated at nonbearing surfaces rather than the intended primary bearing was studied in postmortem specimens from 30 patients with total hip arthroplasty. Using light and electron microscopy with x-ray microanalysis, submicrometer metal particles were identified within macrophages in the liver and/or the spleen in 11 of 15 patients with a revised arthroplasty and in 2 of 15 patients with primary hip arthroplasty. The macrophages formed focal aggregates in the organs without apparent toxicity. Fretting at ancillary fixation devices, loose components, and modular connections can generate a substantial volume of debris. These particles are in addition to those generated at the bearing surfaces, further increasing both the local and systemic particulate burdens. While all components can be associated with the distant spread of particles and metal ions, it is the environment of revision arthroplasty that provides the greatest potential for the generation and systemic dissemination of wear debris. The long-term effects of accumulated wear particles in the liver and spleen are unknown.

Adult↗

PubMed2004

Can metal levels be used to monitor metal-on-metal hip arthroplasties?

In this review, the prospects for using blood, serum, and/or urine metal levels for monitoring the performance of metal-on-metal hip arthroplasty systems are explored. This approach does have substantial potential for serving this function; however, the methodology is technically challenging and the interpretation of the values requires an extensive database with correlative clinical information. At this time, it is premature to recommend metal concentration analysis on a routine clinical basis for patients with metal-on-metal total hip arthroplasties. Nonetheless, metal concentration analysis remains a powerful research tool in the evaluation of metal-on-metal hip arthroplasty systems.

Arthroplasty, Replacement, Hip↗

PubMed2004

Differences in the fretting corrosion of metal-metal and ceramic-metal modular junctions of total hip replacements.

The use of modular interlocking components is a central design feature of total joint replacements. In this investigation we hypothesized that clinically available ceramic-metal modular connections used in total hip arthroplasty release more metal through fretting corrosion than traditional metal-metal modular connections. This was investigated using an in vitro comparison of ceramic (zirconia, ZrO2) and metal (Co-alloy) femoral-head fretting upon Co-alloy stem components. In vitro fretting corrosion testing consisted of potentiodynamic monitoring and analysis of metal release from zirconia and Co-alloy 28 mm femoral heads with similar surface roughnesses (Ra=0.46 microm) on identical Co-alloy stems at 2.2 kN for 1x10(6) cycles at 2 Hz. In contrast to our original hypothesis, we found greater metal release (approximately 11-fold increase in Co and 3-fold increase in Cr) and potentiodynamic fretting of metal-metal modular junctions when compared to ceramic-metal. Potentiodynamic testing demonstrated that lower initial voltages (-266<153 mV), greater maximum voltage changes (116>56 mV, p<0.05, t-test) and voltage variability (3>0.5 mV, p<0.05, t-test) were associated with the open circuit potentials of Co-alloy on Co-alloy junctions when compared to zirconia on Co-alloy junctions. In this study of a single total hip replacement stem and head design, zirconia heads mated with Co-alloy stems produced less fretting than Co-alloy heads mated with Co-alloy stems. Although further studies are necessary with a variety of implant designs and under different experimental conditions, the evidence presented here should, in part, alleviate concerns of increases in fretting corrosion at modular junctions of ceramic-metal coupled components.

Adult↗

PubMed2004

Mechanisms of failure of total hip replacements: lessons learned from retrieval studies.

The value of implant retrieval analysis in orthopaedic surgery has been well recognized. Prosthetic devices retrieved for cause at revision surgery (for implant failure) or devices retrieved postmortem from patients with clinically successful reconstructions provide a unique set of specimens that can be studied to evaluate the effect of the implant on the host environment and the effect of the host environment on the implant. A systematic analysis of retrieved components, in combination with histologic, radiographic, and clinical data can provide valuable insights into the mechanisms of failure of the biomaterials used in joint replacement applications. From the hip implant retrieval studies reported to date, it has been established that the local reaction to particulate wear debris initiates the formation of a granulomatous tissue that ultimately invades the bone-implant interface and results in aseptic loosening. Cement mantle defects, noncircumferential porous coatings, and screw holes can serve as preferential access pathways for the progression of this granulomatous process yielding distinctive patterns of implant loosening and osteolysis. Continued surveillance of retrieved devices is strongly recommended to deepen our understanding of implant failure mechanisms and to evaluate the impact of newer designs and materials on the performance of joint replacement devices.

Animals↗

PubMed2004

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. No patient was lost to followup. The average followup was 13 years (range, 11-15 years). The mean preoperative Hospital for Special Surgery knee score of 55 points (range, 30-79 points) improved to a mean of 90 points (range, 60-100 points) at final followup. Patellofemoral symptoms were present in 1.6% of patients at 10 years; this increased markedly to 10% of patients at 15 years (p < 0.01). Four patients (10%) had moderate or severe patellofemoral symptoms at final followup; two were revised to a primary total knee replacement at 7 and 11 years for progressive patellofemoral degeneration. No component was radiographically loose and no osteolysis was seen. The Kaplan-Meier survival with loosening or revision for any reason was 98.0% +/- 2.0% at 10 years and 95.7% +/- 4.3% at 15 years. At up to 15 years, unicompartmental knee arthroplasty yielded good clinical results; however, progressive patellofemoral arthritis was the primary mode of failure.

Aged↗

PubMed2004

Rapid rehabilitation and recovery with minimally invasive total hip arthroplasty.

To assess the potential recovery rate of a minimally invasive total hip replacement technique with minimal soft tissue disruption, an accelerated rehabilitation protocol was implemented with weightbearing as tolerated on the day of surgery. One hundred consecutive patients were enrolled in this prospective study. Ninety-seven patients (97%) met all the inpatient physical therapy goals required for discharge to home on the day of surgery; 100% of patients achieved these goals within 23 hours of surgery. Outpatient therapy was initiated in 9% of patients immediately, 62% of patients by 1 week, and all patients by 2 weeks. The mean time to discontinued use of crutches, discontinued use of narcotic pain medications, and resumed driving was 6 days postoperatively. The mean time to return to work was 8 days, discontinued use of any assistive device was 9 days, and resumption of all activities of daily living was 10 days. The mean time to walk (1/2) mile was 16 days. Furthermore, there were no readmissions, no dislocations, and no reoperations. Therefore, a rapid rehabilitation protocol is safe and fulfills the potential benefits of a rapid recovery with minimally invasive total hip arthroplasty.

Adult↗

PubMed2004

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. Three of the 142 metal shells failed secondary to aseptic loosening. Ten hips (7%) required a change of the modular acetabular liner because of excessive wear or for the treatment of osteolysis. The fifteen-year rate of survival of the metal shell, with failure defined as revision because of loosening or radiographic evidence of loosening, was 99%. The rate of survival of cementless acetabular reconstructions was excellent at fifteen years, although osteolysis and reoperations were noted to occur much more frequently as the duration of follow-up increased. The majority of the complications were related to wear of the polyethylene liner.

Acetabulum↗

PubMed2004

Extensor mechanism allograft reconstruction after total knee arthroplasty. A comparison of two techniques.

BACKGROUND: Disruption of the extensor mechanism is an uncommon but catastrophic complication of total knee arthroplasty. We evaluated two techniques of reconstructing a disrupted extensor mechanism with use of an extensor mechanism allograft following total knee arthroplasty. METHODS: Twenty consecutive reconstructions with use of an extensor mechanism allograft consisting of the tibial tubercle, patellar tendon, patella, and quadriceps tendon were performed. The first seven reconstructions (Group I) were done with the allograft minimally tensioned. The thirteen subsequent procedures (Group II) were performed with the allograft tightly tensioned in full extension. All surviving allografts were evaluated clinically and radiographically after a minimum duration of follow-up of twenty-four months. RESULTS: All of the reconstructions in Group I were clinical failures, with an average postoperative extensor lag of 59 degrees (range, 40 degrees to 80 degrees ) and an average postoperative Hospital for Special Surgery knee score of 52 points. All thirteen reconstructions in Group II were clinical successes, with an average postoperative extensor lag of 4.3 degrees (range, 0 degrees to 15 degrees ) (p < 0.0001) and an average Hospital for Special Surgery score of 88 points. Postoperative flexion did not differ significantly between Group I (average, 108 degrees ) and Group II (average, 104 degrees ) (p = 0.549). CONCLUSIONS: The results of reconstruction with an extensor mechanism allograft after total knee arthroplasty depend on the initial tensioning of the allograft. Loosely tensioned allografts result in a persistent extension lag and clinical failure. Allografts that are tightly tensioned in full extension can restore active knee extension and result in clinical success. On the basis of the number of knees that we studied, there was no significant loss of flexion. Use of an extensor mechanism graft for the treatment of a failure of the extensor mechanism will be successful only if the graft is initially tensioned tightly in full extension. LEVEL OF EVIDENCE: Therapeutic study, Level III-2 (retrospective cohort study). See Instructions to Authors for a complete description of levels of evidence.

Aged↗

PubMed2003

Spinal implant debris-induced osteolysis.

STUDY DESIGN: Generally, implant-induced osteolysis is a manifestation of an adverse cellular response to phagocytosable particulate wear and corrosion debris. Initially termed "cement disease," particle-induced loosening was recognized by Charnley in the early 1960s. Despite the plethora of information gained over the last 40 years on the basic science of periprosthetic bone loss, much remains unanswered. The effect of unintended debris resulting from wear and corrosion (e.g., micromotion between the interconnection mechanisms in spinal implants) remains a clinical concern. The current study highlights what is known of particle-induced osteolysis and how the presence of spinal implant particulate debris deleteriously influences osseointegration of posterolateral bone graft or disrupts an established posterolateral fusion mass. Tissue explant, animal, and cell culture studies have revealed the complexity of cellular reactivity involved in aseptic particle-induced osteolysis. OBJECTIVES: The objectives of this study are twofold: 1) to highlight the dominant cellular participants in total joint arthroplasty particle induced osteolysis, which are purportedly the macrophage, osteoblast, fibroblast, and osteoclast and several of the dominant chemical mediators have been identified as well, which include prostaglandin E2, tumor necrosis factor-alpha, interleukin-1, and interleukin-6; and 2) to demonstrate the potential deleterious effects of spinal implant debris using animal models and analysis of soft tissue surrounding spinal implants in symptomatic patients. METHODS: There are a growing number of proinflammatory and anti-inflammatory cytokines, prostenoids, and enzymes that have been shown to play important roles in the pathology of particle-induced osteolysis. Reports that aseptic granulomatous inflammation typical of that associated with corrosion debris appear to correlate with the complexity of the implant. Titanium particulate material was used to induce effects in 34 New Zealand White rabbits where analysis included serological quantification of systemic cytokines. Postmortem microradiographic, immunocytochemical, and histopathologic assessment of the intertransverse fusion mass quantified the extent of osteolysis, local proinflammatory cytokines, osteoclasts and inflammatory infiltrates. Clinical analysis of 12 patients more than 0.4 years after spinal implants (mean 4.03, range 0.4 to 11 years) presented with late operative site pain. RESULTS: Currently the etiology of this inflammation around spinal implants resembles particle-induced osteolysis around joint arthroplasties where there typically is a self-perpetuating fibroinflammatory zone adjacent to the implant, where macrophage exhaustion, reactive oxygen intermediates, and pro-inflammatory cytokines affect a host of local cell types and induce a widening zone of soft tissue damage and inflammation. Animal model analysis indicated increased levels of local inflammatory cytokines typically associated with osteolysis-tumor necrosis factor-alpha. Osteoclast cell counts and regions of osteolytic resorption lacunas were higher in the titanium-treated versus autograft-alone groups (P < 0.05), and the extent of cellular apoptosis was markedly higher in the titanium-treated sites at both time intervals. Electron microscopy indicated definitive evidence of phagocytized titanium particles and foci of local, chronic inflammatory changes in the titanium-treated sites. CLINICAL CASES: 11 of 12 clinical cases demonstrated elevated tumor necrosis factor-alpha levels and an increased osteoclastic response in the vicinity of wear debris caused by dry frictional wear particles of titanium or stainless steel. Resection of the wear debris and surrounding fibroinflammatory zone resolved clinical symptoms in all 12 cases. CONCLUSIONS: More basic science and clinical research is needed to develop novel strategies for gaining knowledge, and developing effective evaluation and treatment of patients with implant debris related osteolysis. Titanium debris simulating that produced by spinal implants introduced at the level of a spinal arthrodesis elicits an inflammatory cytokine mediated particulate-induced response through increased expression of intracellular TNF-alpha, increased osteoclastic activity and cellular apoptosis. This study highlighted the association between spinal implants particulate wear debris and increased potential for osteolysis. Aseptic osteolysis is among the primary reasons for failure of orthopedic implants. Increased awareness of this destructive process is becoming more important with the growing popularity of total disc arthroplasty and highly modular spinal implants.

Adult↗