Propagation of Human Nasal Chondrocytes in Microcarrier Spinner Culture

Objective

The aim of this study was to test the effectiveness of nasal septal chondrocytes, propagated in microcarrier spinner culture, as an alternative tissue source of chondrocytic cells for cartilage grafts for head and neck surgery and for articular cartilage repair.

Methods

We harvested chondrocytes from 159 patients, ranging in age from 15 to 80 years and undergoing repair of a deviated nasal septum, and propagated the cells in a microcarrier spinner culture system. The nasal chondrocytes proliferated and produced extracellular matrix components similar to that produced by articular chondrocytes.

Results

In microcarrier spinner culture on collagen beads, chondrocyte numbers increased up to 14-fold in 2 weeks. After a month, the microcarriers seeded with nasal chondrocytes began to aggregate, producing a dense cartilage-like material. The newly synthesized extracellular matrix was rich in high molecular weight proteoglycans, and the chondrocytes expressed type II collagen and aggrecan but not type I collagen.

Conclusion

These studies support the feasibility of engineering cartilage tissue using chondrocytes harvested from the nasal septum. Injectable and solid formulations based on this technology are being evaluated for applications in craniomaxillofacial reconstructive surgery and for plastic and orthopedic surgery practices.

When Is Osteonecrosis Not Osteonecrosis?: Adjudication of Reported Serious Adverse Joint Events in the Tanezumab Clinical Development Program

OBJECTIVE

Tanezumab, a monoclonal antibody against nerve growth factor, has demonstrated efficacy in clinical trials of chronic pain in osteoarthritis (OA) and chronic low back pain. Unexpected adverse events (AEs) described as osteonecrosis (ON) occurred during tanezumab development, leading the US Food and Drug Administration to impose a partial clinical hold for all indications except cancer pain. A blinded Adjudication Committee (AC) including orthopedic surgeons, rheumatologists, and an orthopedic pathologist reviewed and adjudicated joint-related AEs in the tanezumab clinical program.

METHODS

The AC adjudicated all reported cases of ON as well as cases of total joint replacements (TJRs) not reported as ON for which radiographs obtained within 9 months of the surgery were available. The AC prespecified categories for joint safety events including primary ON, worsening OA (rapid progression of OA [RPOA], normal progression of OA, insufficient information to distinguish between rapid and normal progression of OA), other, or insufficient information to distinguish between primary ON and worsening OA or another diagnosis.

RESULTS

The AC reviewed events in 249 of 386 patients with an investigator-reported AE of ON and/or a TJR. Two events were adjudicated as primary ON, 200 events were adjudicated as worsening OA (68 of which were classified as RPOA), 29 events had another diagnosis, 11 had insufficient information to distinguish primary ON from worsening OA, and 7 did not have committee member consensus.

CONCLUSION

Despite initial reports, tanezumab treatment was not associated with an increase in ON but was associated with an increase in RPOA. Higher doses of tanezumab, tanezumab administered with nonsteroidal antiinflammatory drugs, and preexisting subchondral insufficiency fractures were risk factors for RPOA in this cohort.

Total hip arthroplasty: differences in outcome measures between men and women

INTRODUCTION

Patient-related factors impact the long-term survival of hip arthroplasty. This study evaluated whether there were differences in outcome measures between men and women undergoing total hip arthroplasty.

METHODS

A retrospective study of prospectively collected data on 75 primary total hip arthroplasties in 72 patients was conducted. Medical history, physical examination, Harris Hip scores, and Quality of Life forms (SF-36) were obtained for each patient preoperatively and postoperatively. Preoperative radiographs were assessed using the Kellgren and Lawrence scoring system. Only patients with a minimum follow-up of 2 years were included.

RESULTS

Preoperatively, women and men had comparable Kellgren and Lawrence scores and Harris Hip scores. Of the 8 subscores for the SF-36, only the Physical Functioning subscore was significantly different preoperatively. Similar results were noted postoperatively; again, only the Physical Functioning subscores were significantly different between men and women.

CONCLUSIONS

Physician assessments were not significantly different preoperatively and postoperatively for men or women. The results for the SF-36 were similar except for a significant difference in the Physical Functioning subscore preoperatively and postoperatively. According to the Medical Outcomes Trust, the SF-36 Physical Functioning score has been shown to be the best all-around measure of physical health.

Bone mineral density of the femur in autopsy retrieved total knee arthroplasties

Bone mineral density (BMD), as measured by DEXA, can vary depending on bone rotation and fat content of soft tissues. We performed DEXA measurements, under controlled positioning, on 24 autopsy-retrieved femora from patients who had fully functional and asymptomatic successful TKA to determine periprosthetic BMD changes and compared results to 24 normal cadaveric femora. In TKA specimens, BMD was affected by gender, preoperative diagnosis, and zone under analysis. The lowest mean BMD was in the anterior femoral condylar zone. Males had higher mean BMD at all zones while patients with preoperative diagnosis of osteoarthritis had higher BMD in the posterior condylar zone. The mean BMD in the anterior femoral condylar zone in TKA specimens was significantly lower than in normal specimens without arthroplasties, most likely due to stress shielding.

Synergistic effect of using a transcutaneous electrical joint stimulator and an unloading brace in treating osteoarthritis of the knee

Medical treatments and less invasive surgical approaches for knee osteoarthritis are variably effective, and total knee arthroplasty (TKA) is generally reserved for the most severe cases. The care gap between more conservative treatments and TKA leaves many patients with unresolved pain and loss of function for long periods. We conducted a study to determine if incorporating the BioniCare stimulator into an unloading brace would produce more rapid improvement and result in increased adherence and efficacy. Two hundred eighty-nine patients treated only with BioniCare served as historical controls and were compared with 225 patients treated with BioniCare combined with an unloading brace. Means and standard deviations of the changes in scores for pain intensity in the past 48 hours, pain and associated symptoms, patient global assessment, pain on going up or down stairs, and pain on walking on a flat surface and the effect sizes at 1, 3, 6, and 12 months, as well as the percentages of patients achieving at least 20% improvement, and at least 50% improvement, demonstrated that treatment with stimulator and unloading brace combined was significantly superior to treatment with the stimulator alone.

Cementing polyethylene liners into non-modular acetabular components in revision total hip arthroplasty

PURPOSE

To review mid-term results after replacing the polyethylene liner in a well-fixed acetabular shell.

METHODS

22 patients underwent replacement of the polyethylene liner in a well-fixed acetabular shell using cementation. The inner surface of the metal shell was scored with grooves (1 to 2 mm deep) for cement interdigitation. Trial liners were used to assess the appropriate size, with an aim to provide at least 2 mm of an even cement mantle behind the polyethylene liner. None of the liners were constrained or lipped. Clinical and radiographic outcomes were evaluated, and Harris Hip Scores obtained. Radiographic loosening of the acetabular shell was recorded. Implant survival was evaluated using the Kaplan- Meier estimator.

RESULTS

After a mean follow-up of 70 (range, 21-189) months, 17 patients had stable hips and their mean Harris Hip Score was 89 (range, 72-93). Four patients underwent re-revision after 28 to 108 months for aseptic loosening of the acetabular shell (n=2) and recurrent dislocation (n=2). One patient showed radiographic evidence of acetabular migration but was stable. The femoral components of all patients were stable. 92% of patients had good-to-excellent results. Implant survival at 60 months was 81% (95% confidence interval [CI], 51-94%); it became 91% (95% CI, 61-99%) if reductions for dislocations were excluded.

CONCLUSION

Cementation of an undersized polyethylene liner into a non-modular shell is one option for revision of a well-fixed acetabular shells. Nonetheless, further follow-up is required to determine if it remains a viable option in the long term. If there is any doubt about the stability of the acetabular shell, a complete revision should be performed.

Extra-articular deformity is always correctable intra-articularly: to the contrary

The operative word in this debate is "always." In my opinion, there are some cases better served by extra-articular correction. The question then becomes which ones, and how does the surgeon determine? There are 4 considerations: the magnitude of the deformity, the relationship of the deformity to the knee, the side of the deformity (varus or valgus), and whether the femur or the tibia is affected by the deformity. A larger deformity is more important, but just as important is its relationship to the knee. Large deformities distant to the knee have little impact on the knee. Varus deformities require lateral intra-articular overresection, which produces lateral instability. Valgus deformities require medial overresection, which produces medial instability. Lateral instability is stabilized by the dynamic lateral stabilizers (popliteus, lateral head of the gastrocnemius, biceps femoris, and iliotibial tract) and is better tolerated than medial instability. The best way to determine the consequence of the malalignment in question is to template the knee by drawing the mechanical axis from the femoral head or ankle to the center of the knee, and then the resection level that will be required. This will demonstrate the amount of overresection required to correct the extra-articular deformity, and in some cases will indicate the advantage of an extra-articular correction.

Internet access produces misinformed patients: managing the confusion

The Internet has produced a truly phenomenal increase in access to information. This is really only helpful to patients if the information is filtered and appropriate to their specific needs. Too often patients access information about conditions they have self-diagnosed and bring it to the consultation with their physician, who then has to spend time disabusing the patients of the misinformation they have accumulated. Patients also return home from their initial consultation, access the Internet, and come up with all manner of promotional information from companies and even orthopedic practices that they want explained to them by their physician. It is the overwhelming conclusion of orthopedic specialists that this kind of Internet use is actually a burden for them in caring for patients and is not contributing to patient enlightenment. It does not have to be this way, if physicians will do just 2 things: first, create white papers for patients that address common current questions, such as surgical approach or bearing surfaces for implants and why we do what we do. This is a huge time saver and will preempt many questions. Second, develop their own website or select excellent nonprejudicial sites to which they can refer patients. To do less will invite a neverending parade of questions irrelevant to patient welfare.

Outcome of uncemented primary femoral stems for treatment of femoral head osteonecrosis

Cementless total hip replacement has been advocated for patients with osteonecrosis of the femoral head. This study examined the outcome of the femoral stem of four generations of an uncemented, proximally porous-coated, chrome-cobalt total hip prosthesis. There were 158 cases in 141 osteonecrosis patients (74 men, 67 women) who had a mean age of 46 years (range, 17-83 years). The mean follow-up was 103 months (range, 20-235 months). The femoral components of 144 cases were not revised and had a mean Harris hip score of 84 (+/-15) at final follow-up. Of the 14 revisions (8.9%), the primary reasons for revision were loosening or significant osteolysis. There were one infection and one chronic dislocation. Proximally porous-coated, anatomic, press-fit stems provide excellent long-term results in patients with osteonecrosis of the femoral head.

Characterization and pathological characteristics of spontaneous osteonecrosis of the knee

OBJECTIVE

Spontaneous osteonecrosis of the knee affects patients typically over the age of fifty-five years. Evidence exists that this process may not be true necrosis. The purpose of this study was to characterize the demographic, radiographic, and pathologic features of this condition.

MATERIALS AND METHODS

Twenty-one patients (twenty-two knees) consecutively treated for spontaneous osteonecrosis of the knee were studied.

RESULTS

Only one of twenty-two specimens demonstrated evidence of bone necrosis. No specimens showed fat necrosis, marrow necrosis, fibrous change or appositional bone repair. Fourteen of twenty-two specimens (64%) showed significant osteopenia and fifteen of twenty-two specimens (68%) showed evidence of osteoarthritis.

CONCLUSIONS

This study demonstrated that spontaneous osteonecrosis of the knee is not an osteonecrotic condition and has been misnamed. Osteopenia and osteoarthritis may play a role in the pathogenesis of this disease.

Resection arthroplasty for failed patellar components

A total of 1,401 primary total knee arthroplasties (TKA) were reviewed; 44 (3.2%) had at least the patellar component revised. Nine of these knees (eight patients) had insufficient bone stock to allow reimplantation of another patellar component. Clinical data on the nine knees were obtained with recent follow-up evaluation, review of their medical records and radiographs. Evaluation included Hospital for Special Surgery (HSS) scores. Average follow-up was 4 years and 7 months, 2-year range (2 months to 8 years and 4 months). Common factors found in these nine knees included: thin patella after primary TKR status, osteoarthritis, good range of motion and patella alta. Results were good to excellent in seven knees and fair in two. The untoward associations with patellectomy such as quadriceps lag, extension weakness and anterior knee pain were not experienced. Resection of the patellar component, without reimplantation, is an acceptable alternative in revision TKA lacking adequate remaining bone stock.

High-impact sports after total knee arthroplasty

Many patients will attempt high-impact loading activities after total knee arthroplasty. This study analyzed the clinical and radiographic results of these high-demand sports patients. A total of 31 patients (33 knees) were identified who participated in high-impact sports on average 4 times per week (range, 1-7 times per week) for a mean of 3.5 hours per week (range, 1 to 10 hours), including jogging, downhill skiing, singles tennis, racquetball, squash, and basketball. At 4 years mean follow-up (range, 2-9 years), 32 of 33 knees had successful clinical and radiographic outcomes. Overall satisfaction was a mean of 9.1 points on a scale of 0 to 10 points. These results indicate that some patients will participate in high-impact sports and enjoy excellent clinical outcomes at a minimum 4 years after surgery.

Bone scanning of limited value for diagnosis of symptomatic oligofocal and multifocal osteonecrosis

OBJECTIVE

Bone scintigraphy has been advocated as a useful diagnostic tool for patients with suspected osteonecrosis or in screening for multifocal disease. We evaluated the sensitivity of bone scanning relative to magnetic resonance imaging (MRI) in the diagnosis of osteonecrosis.

METHODS

Forty-eight patients presented with suspected osteonecrosis of the shoulder, hip, knee, or ankle. All patients underwent simultaneous (< 3 months apart) bone scans and MRI studies as part of diagnostic investigations. Histological confirmation of osteonecrosis was obtained for all suspected lesions. The diagnostic result for each imaging modality was then assessed and compared.

RESULTS

All 163 (100%) histologically confirmed lesions were identified by MRI, while only 91 lesions (56%) were identified by bone scan. There was complete congruency of bone scans with MR images in only 38% of patients (18/48). Bone scanning identified 72% of lesions (47/65) in oligofocal patients (< or = 2 joints involved) compared with 45% of the lesions (44/98) in multifocal patients (> or = 3 joints involved). Sensitivity of lesions was highest for the knee and hip and lower for the shoulder and ankle. Larger and later-stage lesions had a higher bone scan sensitivity.

CONCLUSION

Our results demonstrated the low sensitivity of bone scintigraphy for diagnosing symptomatic osteonecrosis. It is least sensitive for early-stage lesions where it might be most useful to diagnose the disease. Our study also confirms that this test is less sensitive for joints other than the hip and is also not useful as a screening tool. Our study does not support the use of bone scans as a diagnostic or screening tool for osteonecrosis.

Knee arthroplasties have similar results in high- and low-activity patients

With increased patient demand to return to active lifestyles, total knee arthroplasties have evolved from primarily providing pain relief to allowing for increased function and mobility. We evaluated the influence of activity on the outcome of total knee arthroplasties. The overall satisfaction, rate of revision, and clinical and radiographic results for high-activity patients were compared with a matched group of low-activity patients at a minimum followup of 4 years (mean, 7 years; range, 4-14 years). There were 22 men and 35 women (72 knees) in each group. High-activity patients fared as well as their low-activity counterparts with no differences in clinical outcomes. At the time of last followup, mean Knee Society objective scores were 95 points (range, 70-100 points) and 96 points (range, 80-100 points) for the high-activity and low-activity groups, respectively. The high-activity group had one clinical failure, and neither group had any revisions. The groups had similar radiographic outcomes with no progressive radiolucencies and no evidence of osteolysis. While we await long-term results, these results suggest that low- to moderate-impact sports activities had no effect on the clinical and/or radiographic outcomes of total knee arthroplasties at mid-term followup.

Trial reduction: the last chance to get it right

Trial reduction at total knee arthroplasty is an integral part of the procedure. It is the last thing that is done before the components are implanted and the knee is closed. Perhaps because it is the last step, it is getting less attention than it deserves. It is obvious from some of the postoperative radiographs seen in our clinic that the surgeon could not have done a careful trial reduction. This article defines the importance of performing a careful trial reduction and points out some of the pitfalls in detecting the true cause of the abnormality that might be detected at trial reduction. It implores the surgeon to give the proper attention to the importance of this part of the procedure.

Treatment of osteonecrosis of the femoral head: everything's new

Since the 1970s, the mantra of those treating osteonecrosis of the femoral head was to save the head at all costs. Total hip arthroplasty (THA), the only effective surgical treatment once the head has mechanically and clinically failed, had a poor track record for young active patients. Recently, THA using highly cross-linked polyethylene, metal-on-metal bearing surfaces, or ceramic-on-ceramic bearing surfaces have given promising results, changing the "save-at-all-costs" paradigm. Operations that have a low success rate, high complication rate or morbidity, or compromise subsequent THA can no longer be justified. This includes femoral osteotomy and free vascularized fibular graft. Core decompression is justified, when indicated, because of its low morbidity and absence of complications with subsequent THA.

Patellar meniscus in total knee arthroplasty

Twenty-four clinically successful, autopsy retrieved porous-coated anatomic total knee arthroplasty (TKA) specimens were evaluated to determine the structure and function of the patellar meniscus. Mean implant duration was 76 months (range: 11-135 months). Histological examination showed the patellar meniscus to be composed of dense fibrous tissue with scattered regions of chronic granulomatous response to polyethylene debris. Patellar wear and polyethylene exposed patellar surface area were correlated with implant duration (r = 0.47, P = .03; r = 0.52, P = .06). Postoperative patellar tilt was also associated with patellar component wear (r = 0.64, P = .03). No other clinical measures were significantly associated with patellar wear or exposed surface area. Additional research is needed to determine what role, if any, the patellar meniscus plays in TKA outcomes.

Extraction and characterization of metallic wear debris from total joint arthroplasty

Wear debris generated from total joint arthroplasty may elicit a granulomatous and inflammatory response and has also been implicated in the development of osteolysis. Technical difficulty in retrieval and isolation of wear material from tissues has hindered the study of their physicochemical properties. The purpose of this study was to retrieve and analyze metallic wear debris from periprosthetic tissue obtained during revision arthroplasty. Tissue from six osteoarthritic patients was obtained during revision arthroplasty. The tissue was minced and then heated in a sodium dodecyl sulfate solution. Undigested tissue was incubated sequentially with papain and pepsin solutions. Metallic wear debris retrieved from the digestion procedure was analyzed by scanning electron microscopy. Wear fragments were seen as irregularly shaped flakes, splinters and polyhedral structures ranging from 1 to 100 microns in size. These structures appeared to be free from non-metallic surface-adherent material. Energy dispersion spectroscopy verified the presence of cobalt, chrome and molybdenum which comprised the implant alloy. Fatigue lines were observed on the surface suggesting brittle wear. Our technique for isolating metallic fragments facilitates the retrieval and preparation of wear debris for analysis of physicochemical properties and how wear debris interacts with cellular elements in surrounding tissue.

The pathogenesis of osteonecrosis

Although numerous studies concerning the pathogenesis of osteonecrosis have been published, the pathophysiologic mechanisms that may be involved continue to be debated. In the early 1980s, the concept of accumulative cell stress was advanced, which is a theory that proposes that bone cells are exposed to multiple insults or stresses, the effects of which accumulate to the point that the cells cannot sustain themselves and die. Technologic advances have led scientists to a better understanding of cell and molecular biology, and recent studies of osteonecrosis and its risk factors have indicated that this concept should be revisited. It now appears that using the term "necrosis" may be incorrect and that apoptosis may play a significant role. Research on osteoporosis, fracture healing, bone graft incorporation, hematology, and genetics may lend insight into the etiology and pathogenesis of osteonecrosis. Several studies on osteoporosis have focused on the effect of exogenous glucocorticoids on the behavior of osteocytes, osteoblasts, osteocytes, and their precursors. Recent findings on osteonecrosis and bone biology are placed into the context of what has been previously reported.

Survivorship of femoral revision hip arthroplasty in patients with osteonecrosis

BACKGROUND

Recent studies have indicated that the rate of successful long-term outcome after primary total hip arthroplasty for patients with osteonecrosis may be improved with the use of later-generation porous-coated prostheses (biologic ingrowth fixation) and cement techniques (cement fixation). Less is known about the long-term outcome after revision arthroplasty in the same patient population. The purpose of this study was to characterize the clinical and radiographic outcomes of revision total hip arthroplasty in patients with osteonecrosis.

METHODS

We evaluated thirty-four osteonecrotic hips in thirty patients who had undergone revision of a femoral component of a prior total hip arthroplasty. There were nineteen men (twenty-two hips) and eleven women (twelve hips) with a mean age of forty-six years. Thirty one of thirty-four hips were implanted without cement. The cementless prostheses were of different stem lengths, but thirty of thirty-one were proximally porous coated. The mean duration of follow-up was 8.2 years. Prerevision radiographs were used to determine the degree of femoral bone loss according to the classification system of Della Valle and Paprosky. The need for revision was analyzed for correlation to known risk factors for osteonecrosis, age and gender of the patient, and degree of prerevision femoral deficiency. A clinical and radiographic evaluation of outcome was performed.

RESULTS

This was the first revision for twenty-seven hips, the second for five hips, and the third for two hips. Preoperatively, the defects included four Type I, nine Type II, fifteen Type IIIA, two Type IIIB, one Type IV, and three unknown. The femoral component was rerevised in twelve of the thirty-four hips. One of the failures was the only fully porous-coated stem that was implanted. One of the three cemented implants failed, as compared with eleven of the thirty-one noncemented implants. Survival rates were 90.9% at five years, 54.8% at ten years, 54.8% at fifteen years, and 27.4% at twenty years. With the small sample size, no relationship could be identified with regard to frequency of re-revision and defects, associated risk factors, patient age, or gender.

CONCLUSIONS

There was a high failure rate of revised, uncemented, proximally coated femoral components in patients with osteonecrosis of the femoral head at the time of the intermediate-term follow-up. The cause of failure could not be correlated with patient age, gender, risk factors for osteonecrosis, or femoral bone stock.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Systematic analysis of classification systems for osteonecrosis of the femoral head

BACKGROUND

Multiple classification systems for osteonecrosis of the hip have been developed to assist physicians in the diagnosis and treatment of this potentially debilitating disorder. The purpose of this analysis was to delineate the classification systems utilized in reports published since 1985 and, through a comparison of the most commonly used systems, to identify consistent factors that would allow for cross-publication comparisons to be made.

METHODS

We performed a PubMed search for reports of outcome studies concerning treatment methods for osteonecrosis of the hip. All studies of reported outcomes with greater than ten patients were included in the analysis. Various classification systems were tabulated to determine usage frequencies. The four most commonly used systems were then analyzed to determine common factors used for classification.

RESULTS

One hundred and fifty-seven studies were available for analysis. Sixteen major classification systems that made use of more than one radiographic factor were identified, and nine of these systems had one to five modifications reported throughout the literature. Additionally, eleven other systems made use of single factors obtained from either magnetic resonance imaging or anatomic data. The review revealed that four classification systems accounted for greater than 85.4% of the reported studies. Parameters for these four systems were stratified to allow for uniformity of patient or study evaluation.

CONCLUSIONS

This analysis of the reported classification systems for osteonecrosis of the femoral head revealed several similarities between the most commonly used systems. An analysis of patients can be made with any of the four major systems if specific data are collected according to various magnetic resonance imaging and radiographic findings. This approach will allow for easier comparison of studies across different centers.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

What would you do? Challenges in hip surgery

The panel reviewed cases involving both revision and primary total hip arthroplasties. The panelists are Hugh Cameron and Allan Gross from Toronto, Charles Engh from Arlington, Aaron Rosenberg from Chicago, and Bernard Stulberg from Cleveland. The cases discussed brought up some controversial issues.

Nontraumatic osteonecrosis of the femoral head: ten years later

The etiology of osteonecrosis of the hip may have a genetic basis. The interaction between certain risk factors and a genetic predisposition may determine whether this disease will develop in a particular individual. The rationale for use of joint-sparing procedures in the treatment of this disease is based on radiographic measurements and findings with other imaging modalities. Early diagnosis and intervention prior to collapse of the femoral head is key to a successful outcome of joint-preserving procedures. The results of joint-preserving procedures are less satisfactory than the results of total hip arthroplasty for femoral heads that have already collapsed. New pharmacological measures as well as the use of growth and differentiation factors for the prevention and treatment of this disease may eventually alter our treatment approach, but it is necessary to await results of clinical research with long-term follow-up of these patients.

The response of osteoblast-like cells to dexamethasone and cyclic loading

The aim of this study was to investigate whether cyclic loading can alter the response of osteoblasts to dexamethasone. Proliferation of osteoblast-like cells (MG-63) was assessed by determining uptake of 3H-thymidine. Three doses of dexamethasone were tested: 0.001 nM, .001 nM, or 0.1 nM. Exposure to increasing levels of dexamethasone resulted in decreased proliferation of osteoblast-like cells. Although there was a slight decrease in proliferation seen in the controls (no dexamethasone) with cyclic loading, cyclic loading did not affect the response of osteoblast-like cells to dexamethasone under these test conditions. Varying loading conditions and the potential effect on metabolic and synthetic activity of the osteoblast-like cells need further study.

Nickel and vanadium metal ions induce apoptosis of T-lymphocyte Jurkat cells

Metal alloys are used as prosthetic components in the orthopaedic and dental field. However, there is growing concern over the reported leaching of metal ions from implants. Ions released from metals have been thought to be associated with local immune dysfunction, inflammation, and tissue cell death. The objective of our study was to investigate whether nickel(II) and vanadium(V), present at a smaller percentage in most alloys, are cytotoxic to T-lymphocyte cell models. Jurkat T cells possess characteristics similar to human T-lymphocytes and proliferate at a faster rate. Jurkat T cells were incubated with control media alone or with concentrations of 1, 10, and 100 microg/mL of Ni(II) or V(V) for 24 h. Both types of metal ions reduced cell viability and proliferation in a dose-dependent manner. Ni(II) at 10 microg/mL and V(V) at 100 microg/mL activated Caspase-3 expression. Hoechst 33258 staining and transmission electron microscopy revealed chromatin condensation, as well as nuclear blebbing and fragmentation. Induction of DNA fragmentation by Ni(II) at 100 microg/mL was also indicated by agarose electrophoresis. Our observations indicate that Ni and V ions kill T cells via apoptotic and nonapoptotic pathways.

What would you do? Case challenges in knee surgery

These knee arthroplasty cases were presented to a panel of surgeon and they represent classic clinical problems: (1) indications for unicompartmental arthroplasty; (2) total knee arthroplasty after a high tibial osteotomy complicated by infection and extensor mechanism rupture; (3) neuropathic arthropathy; (4) posttraumatic osteoarthritis with extraarticular deformity; (5) degenerative arthritis in the young patient; (6) osteoarthritis with a valgus deformity, fixed flexion contracture, degenerative scoliosis, and leg length discrepancy.

Metal-on-metal resurfacing arthroplasty: no way under the sun!--in the affirmative

I have been charged in this debate format to refute the idea suggested in the title. To do this, I will address 2 questions: (1) What problem does it solve? and (2) What risk does it pose? The answers to these questions will support my conclusion that metal-on-metal resurfacing arthroplasty is the wrong operation to be making a reappearance at this time.

Induction of osteoblast aggregation, detachment, and altered integrin expression by bear serum

Animal models have long been used to elucidate the mechanisms responsible for osteoporosis in humans. The American black bear, an animal that does not experience extensive bone loss normally associated with long-term immobilization (when hibernating), may provide an insight into the nature of the pathogenesis of the disease. Circulating growth and differentiation factors present in the serum may facilitate continued proliferation of bone-forming cells. The aim of our study was to determine the effects of bear serum on human osteoblasts when cultured for extended periods of time. Unexpectedly, exposure to the bear serum in vitro led to the detachment of osteoblasts from the surface of the culture plate after 3 d of incubation. The osteoblasts pulled off the polystyrene surface in sheets and aggregated into floating conglomerations of viable cells. In contrast, osteoblasts cultured in fetal calf serum maintained adherence to the surface of the culture plate. Detachment of osteoblasts propagated in bear serum was time dependent and was associated with an increased expression of integrins compared with osteoblasts propagated in fetal calf serum, as indicated by reverse transcriptase-polymerase chain reaction and immunostaining.

Ginger extract components suppress induction of chemokine expression in human synoviocytes

INTRODUCTION

Ginger has a long history of medicinal use, particularly as an anti-inflammatory agent for a wide variety of diseases such as arthritis. Suppression of inflammation in arthritis is attributed to suppression of proinflammatory cytokines and chemokines produced by synoviocytes, chondrocytes, and leukocytes.

OBJECTIVE

This study aimed to elucidate the effect of a combination ginger extract and its individual components on chemokine expression in human synoviocytes.

METHODS

Human synoviocytes were incubated with 100 microg/mL combination ginger extract (GE) of Alpinia galanga (AG) and Zingiber officinale (ZO); AG extract alone; ZO extract alone; or control media, for 1 hour at 37 degrees C, 5% CO2. Cells were next activated with 1 ng/mL of tumor necrosis factor alpha (TNF-alpha) for 1 hour to determine macrophage chemotactic factor (MCP-1) and interferon-gamma activated protein (IP-10) mRNA levels using reverse transcriptase polymerase chain reaction (RT-PCR). Secreted MCP-1 and IP-10 were quantified by enzyme-linked immunosorbent assay (ELISA) following a 24 hour incubation period.

RESULTS

The GE combination was consistently more effective in decreasing chemokine mRNA and chemokine secreted protein levels than its individual components ZO or AG. In comparison, ZO was more effective than AG in suppressing chemokine expression.

CONCLUSION

The present study demonstrates that GE inhibits chemokine expression, and that the combination of ZO and AG components acts synergistically. This ginger formulation may be useful for suppressing inflammation due to arthritis.

Asymptomatic osteonecrosis: should it be treated?

Currently, there is no consensus regarding the treatment of precollapse osteonecrosis, particularly for asymptomatic osteonecrosis. With approximately 10,000 to 20,000 new cases of osteonecrosis a year, no single surgeon or center has the kind of experience that is able to address the most important questions concerning this disease. The literature strongly documents that symptoms of osteonecrosis will progress. Although the literature also supports the progression of asymptomatic osteonecrosis to symptomatic osteonecrosis on to collapse, that support is less convincing. Progression is proportional to lesion size, with small lesions (< 15% of femoral head involvement by volume) unlikely to progress. Although the results of core decompression have been somewhat controversial, the weight of the literature supports both the efficacy and safety of the procedure. The decision to treat osteonecrosis with core decompression is primarily based upon lesion size and stage of disease and does not necessarily depend on whether the patient is symptomatic. As large lesions (> 30% of the femoral head) are less likely to be successfully treated by core decompression and small lesions (< 15% of the femoral head) are less likely to progress, asymptomatic lesions within these ranges can be observed. The literature supports the position that moderately sized lesions (15-30% of the femoral head) should be treated by core decompression (with or without bone grafting).

Cartilage debris increases the expression of chondrodestructive tumor necrosis factor-alpha by articular chondrocytes

PURPOSE

To determine if cartilage particles increased the expression of TNF-alpha by articular chondrocytes.

TYPE OF STUDY

In vitro experiment.

METHODS

Articular chondrocytes were obtained from patients undergoing primary total knee arthroplasty for osteoarthritis (n = 3) and from patients undergoing below-knee amputation for peripheral vascular disease (n = 3). Chondrocytes were then incubated with and without cartilage particles at a concentration of 5 microg/10(5) cells for 24 hours. TNF-alpha levels were then determined using reverse transcription polymerase chain reaction.

RESULTS

Both normal and osteoarthritic chondrocytes had low baseline expression of TNF-alpha under standard cell culture conditions. Expression was markedly increased in response to incubation with cartilage particles, and was statistically significant.

CONCLUSIONS

Cartilage debris in the traumatized and osteoarthritic joint may increase the concentration of TNF-alpha in the joint, contributing to joint symptoms and cartilage destruction. Arthroscopic debridement and lavage may improve symptoms by washing these harmful components from the joint.

LEVEL OF EVIDENCE

Level IV.

Cyclic strain stimulates proliferative capacity, alpha2 and alpha5 integrin, gene marker expression by human articular chondrocytes propagated on flexible silicone membranes

Chondrocytes comprise less than 10% of cartilage tissue but are responsible for sensing and responding to mechanical stimuli imposed on the joint. However, the effect of mechanical signals at the cellular level is not yet fully defined. The purpose of this study was to test the hypothesis that mechanical stimulation in the form of cyclic strain modulates proliferative capacity and integrin expression of chondrocytes from osteoarthritic knee joints. Chondrocytes isolated from articular cartilage during total knee arthroplasty were propagated on flexible silicone membranes. The cells were subjected to cyclic strain for 24 h using a computer-controlled vacuum device, with replicate samples maintained under static conditions. Our results demonstrated increase in proliferative capacity of the cells subjected to cyclic strain compared with cells maintained under static conditions. The flexed cells also exhibited upregulation of the chondrocytic gene markers type II collagen and aggrecan. In addition, cyclic strain resulted in increased expression of the alpha2 and alpha5 integrin subunits, as well as an increased expression of vimentin. There was also intracellular reconfiguration of the enzyme protein kinase C. Our findings suggest that these molecules may play a role in the signal transduction pathway, eliciting cellular response to mechanical stimulation.

The incorporation of morselized bone grafts in cementless acetabular revisions

The treatment of large osteolytic lesions is a challenge during acetabular revisions. Periprosthetic bone loss can compromise the stability of new implants. The purpose of this study was to evaluate the 5- to 10-year clinical and radiographic results of morselized bone grafting for acetabular osteolysis during cementless acetabular revisions. Ninety-nine patients (108 hips) who had an acetabular revision hip arthroplasty for osteolysis were retrospectively reviewed. There were 44 men and 55 women who had a mean age of 66 years. At the index revision, the acetabular defects were debrided of granulomatous tissue and packed tightly with morselized cancellous femoral head allograft. All the revision acetabular components were implanted using cementless fixation. At a mean followup of 85 months (range, 60-118 months), the results of 103 of 108 hips (95%) were clinically and radiographically successful. The mean preoperative Harris hip score was 37 points, which improved to a mean of 91 points at the last followup. All cavitary defects had complete radiographic incorporation of the bone grafts except for two lesions. The results of this study indicate that morselized bone graft incorporates into cementless acetabular revisions. This treatment method provided a stable reconstruction in 98% of patients at a mean of 7 years followup.

Osteonecrosis: etiology, diagnosis, and treatment

PURPOSE OF REVIEW

This review provides an update of the recent progress in etiology, pathogenesis, diagnosis, and treatment of osteonecrosis.

RECENT FINDINGS

Concerning pathogenesis, there is evidence that there is a genetic predilection for those who are exposed to the two leading etiologic associations for osteonecrosis: corticosteroids and alcohol. Studies concerning the treatment of osteonecrosis indicate that most preservative (ie, joint-sparing) procedures available today have better results in the precollapse stages of the disease and in smaller lesions. Therefore, researchers continue to develop and modify diagnostic techniques, particularly relating to MRI, for the identification and quantification of osteonecrotic lesions. Advances concerning bone grafting and arthroplasty procedures have resulted in improved clinical outcomes for this patient population. The future treatment of osteonecrosis may involve genetic or cell-based therapies.

SUMMARY

Although progress has been made, considerably more research is needed before we fully understand this disease. Hopefully, such research will lead to effective measures for saving the femoral head or, better yet, preventing osteonecrosis.

Total knee arthroplasty in obese patients: a comparison with a matched control group

Thirty knees in 27 obese patients were matched to 30 knees in 27 nonobese patients, with both cohorts followed for a mean of approximately 15 years. Nine of 30 obese knees were revised, whereas 3 of 30 nonobese knees were revised, with Knee Society objective scores being higher in the nonobese group. There were more polyethylene insert revisions in the nonobese group, which may have been accounted for by a trend of higher activity levels in this group. The authors concluded that at long-term follow-up, although not statistically significant, there was a trend for obesity to influence the rate of aseptic loosening. This may occur because of increasing stress at the bone-prosthesis interface, whereas increased activity levels in the nonobese patients may adversely affect the longevity of the polyethylene insert.

The outcome of total knee arthroplasty in obese patients

BACKGROUND

Evidence linking increased body weight to osteoarthritis of the knee and the high prevalence of obesity underscore the importance of defining the outcome of total knee arthroplasty in obese patients. The purpose of this study was to compare the clinical and radiographic results of total knee arthroplasties performed in obese patients with those of total knee arthroplasties performed in nonobese patients.

METHODS

Clinical and radiographic data on seventy-eight total knee arthroplasties in sixty-eight obese patients were compared with data on a matched group of nonobese patients. The analysis was also performed after stratification of the obese group for the degree of obesity. All patients had the same prosthesis. The clinical data that were analyzed included the Knee Society objective and functional scores, patellofemoral symptoms, activity level, and complications.

RESULTS

The percentage of knees with a Knee Society score of > or =80 points at an average of eighty months was 88% in the obese group, which was significantly lower than the 99% rate in the nonobese group at the same time. The morbidly obese subgroup had a significantly higher revision rate than did the nonobese group (p = 0.02).

CONCLUSIONS

The results of the present study suggest that any degree of obesity, defined as a body mass index of > or =30, has a negative effect on the outcome of total knee replacement.

Minimally invasive total hip arthroplasty: in opposition

At the Knee Society Winter Meeting in 2003, Seth Greenwald and I debated about whether there should be new standards (ie, regulations) applied to the release of information to the public on "new developments." I argued for the public's "right to know" prior to the publication of peer-reviewed literature. He argued for regulatory constraint or "proving by peer-reviewed publication" before alerting the public. It is not a contradiction for me to currently argue against the public advertising of minimally invasive (MIS) total hip arthroplasty as not yet being in the best interest of the public. It is hard to remember a concept that has so captured both the public's and the surgical community's fancy as MIS. Patients are "demanding" MIS without knowing why. Surgeons are offering it as the next best, greatest thing without having developed the skill and experience to avoid the surgery's risks. If you put "minimally invasive hip replacement" into the Google search engine (http://www.google.com), you get 5,170 matches. If you put the same words in PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi), referencing the National Library of Medicine database, you get SEVENTEEN; none is really a peer-reviewed article. Most are 1 page papers in orthopedics from medical education meetings. On the other hand, there are over 6,000 peer-reviewed articles on total hip arthroplasty. Dr. Thomas Sculco, my couterpart in this debate, wrote an insightful editorial in the American Journal of Orthopedic Surgery in which he stated: "Although these procedures have generated incredible interest and enthusiasm, I am concerned that they may be performed to the detriment of our patients." I couldn't agree with him more. Smaller is not necessarily better and, when it is worse, it will be the "smaller" that is held accountable.

Risk factors for pulmonary emboli after total hip or knee arthroplasty

Because it is difficult to predict which patients may sustain a pulmonary embolism after total hip or knee arthroplasty, we assessed multiple thrombophilic and hypofibrinolytic parameters to identify risk factors. Twenty-nine patients who survived a known pulmonary embolism after total knee or total hip arthroplasty were matched by age, gender, race, arthritic diagnosis, procedure, and surgery date with 29 patient-controls who had a total hip or knee arthroplasty but who did not have a symptomatic known pulmonary embolism or deep vein thrombosis. Twenty-one serologic measures and five genes associated with thrombophilia, hypofibrinolysis, or both were assessed without knowledge of group assignment. All patients with pulmonary embolism had at least one abnormality of plasminogen activator inhibitor activity, dilute Russell's viper venom time, prothrombin time, or total cholesterol versus 13 of 27 (48%) control patients. Forty-seven percent of patients who experienced pulmonary embolism had at least two abnormalities of plasminogen activator inhibitor activity, dilute Russell's viper venom time, prothrombin time, or total cholesterol, versus 7% of control patients. Preoperatively, to identify patients at high risk of pulmonary embolism, plasminogen activator inhibitor activity, dilute Russell's viper venom time, prothrombin time, and cholesterol levels were most predictive. Using at least one abnormality of these four measures as a screening test to detect risk of pulmonary embolism, the test is sensitive (100%), and the predictive value of a negative test is high (100%). After additional prospective study, this may allow identification of patients at low risk (the majority of patients) in whom anticoagulation may not be required and a small group of patients at high risk for pulmonary embolism in whom prophylactic anticoagulation should be provided.

An in vitro screening assay for inhibitors of proinflammatory mediators in herbal extracts using human synoviocyte cultures

Tumor necrosis factor-alpha (TNF-alpha), cyclooxygenase (COX)-2, and prostaglandin (PG)E-2 play a critical role in the pathophysiology of arthritis. Tumor necrosis factor-alpha mediates induction of other cytokines, COX-2, PGs, and metalloproteinases, which leads to cartilage degradation. We developed an in vitro human synoviocyte assay system for screening inhibitors of proinflammatory mediators in herbal extracts. Synoviocytes (5 x 10(5) cells/well) obtained during primary knee replacement from osteoarthritic patients were incubated with: control media alone or ginger extract (hydroxy-methoxy-phenyl compounds [HAPC]: EV.EXT 77), 1 h before activation with 1 ng/ml TNF-alpha, 10 ng/ml interleukin-1beta, or control media alone at 5% carbon dioxide, 37 degrees C. Cell viability, TNF-alpha, COX-2, PGE-2, nuclear factor kappaB (NF-kappaB), and inhibitory subunit I kappa B-alpha (IkappaB-alpha) expression were analyzed by reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, electrophoretic mobility shift assay, and Western blots. Ginger extract-HAPC (100 microg/ml) significantly inhibited the activation of TNF-alpha and COX-2 expression in human synoviocytes as well as suppressed production of TNF-alpha and PGE-2. Inhibition of TNF-alpha and COX-2 activation was accompanied by suppression of NF-kappaB and IkappaB-alpha induction. Using our in vitro assay, we discovered that the ginger extract blocks activation of proinflammatory mediators and its transcriptional regulator suggesting its mode of action. These observations indicate that ginger extract-HAPC offers a complementary and alternative approach to modulate the inflammatory process involved in arthritis.

Propagation of human nasal chondrocytes in microcarrier spinner culture

OBJECTIVE

The aim of this study was to test the effectiveness of nasal septal chondrocytes, propagated in microcarrier spinner culture, as an alternative tissue source of chondrocytic cells for cartilage grafts for head and neck surgery and for articular cartilage repair.

METHODS

We harvested chondrocytes from 159 patients, ranging in age from 15 to 80 years and undergoing repair of a deviated nasal septum, and propagated the cells in a microcarrier spinner culture system. The nasal chondrocytes proliferated and produced extracellular matrix components similar to that produced by articular chondrocytes.

RESULTS

In microcarrier spinner culture on collagen beads, chondrocyte numbers increased up to 14-fold in 2 weeks. After a month, the microcarriers seeded with nasal chondrocytes began to aggregate, producing a dense cartilage-like material. The newly synthesized extracellular matrix was rich in high molecular weight proteoglycans, and the chondrocytes expressed type II collagen and aggrecan but not type I collagen.

CONCLUSION

These studies support the feasibility of engineering cartilage tissue using chondrocytes harvested from the nasal septum. Injectable and solid formulations based on this technology are being evaluated for applications in craniomaxillofacial reconstructive surgery and for plastic and orthopedic surgery practices.

Total knee arthroplasty in Ehlers-Danlos syndrome

The Ehlers-Danlos syndromes (EDS) are a rare group of connective tissue disorders characterized by severe joint hypermobility and instability. Ten patients with 12 primary knee arthroplasties were identified. Average age at time of surgery was 43.3 years, with follow-up data acquired at an average of 65 months after surgery. Primary indications for surgery were tibiofemoral or patellar instability (n = 8) and arthritis (n = 4). Knee Society Functional scores averaged 29.6 before surgery and 51.3 at time of interview (P<.005). Knee Society Knee scores at time of follow-up evaluation averaged 70. Tibiofemoral and patella stability were significantly improved. Arthroplasty appears to be an effective option for knee arthritis and instability in EDS patients, although results and satisfaction are lower than that reported for conventional arthroplasty indications.

Evaluation of thermoreversible polymers containing fibroblast growth factor 9 (FGF-9) for chondrocyte culture

We previously evaluated a thermoreversible polymer gel composed of N-isopropylacrylamide and acrylic acid as a cell culture substrate and cell-delivery vehicle. The copolymer promoted phenotype expression and amplification of chondrocytes. In this study, we determined whether addition of fibroblast growth factor 9 (FGF-9), which is mitogenic for chondrocytes, would further enhance cell proliferation and phenotype expression in the polymer. We tested the hypothesis that the thermoreversible polymer containing FGF-9 would promote increased chondrocyte proliferation and phenotype expression. Articular chondrocytes (1 x 10(5)/150 microL) were plated onto control (without gel) and gel containing 24-well plates. The gels were prepared in media alone or in media containing heparin (100 microg/mL) and FGF-9 (5 microg/mL). The cultures were incubated at 37 degrees C in 5% CO(2) for 3 days. Cells remained viable in the thermoreversible polymer in the presence or absence of FGF-9. Addition of FGF-9 to the copolymer did not induce proliferation and the cell numbers did not increase. Reverse transcription polymerase chain reaction (RT-PCR)-determined expression of chondrocyte markers collagen type II and aggrecan. FGF-9 did not enhance chondrocyte proliferation nor alter the phenotype after 3 days in culture. These findings suggest the poly(NiPA-co-AAc) gel alone may provide the optimal 3D environment for propagation of chondrocytes.

Thermally reversible polymer gel for chondrocyte culture

We have evaluated a biomaterial to serve as a scaffold for the propagation and amplification of chondrocytes that promotes the original cellular phenotype of these cells. The goal of the present study was to investigate the use of thermally reversible polymer gels poly(NiPAAm-co-AAc), as a biocompatible supporting scaffold for the propagation of chondrocytic cells. The polymer gels at temperatures above its lower critical solution temperature whereas liquefying at temperatures below its lower critical solution temperature of 34.5 degrees C. Hence, the polymer, in its gelled form, has the ability to hold cells in situ, forming a matrix similar to the natural cellular environment or the extracellular matrix that comprises cartilage. We tested the hypothesis that the polymer gel promotes cell viability and function. Human osteoblast-like cells, nasal chondrocytes, and articular chondrocytes (1 x 10(5)/150 microL) were resuspended in enriched Dulbecco's minimal essential media and were plated onto control (without gel) and gel containing 24-well plates. The plates were reincubated at 37 degrees C, 5% CO(2) for the time point of interest. Additional media was added to the plates and exchanged as needed. After cell culture, cells were retrieved, enumerated, and cell viability was determined. Other aliquots of the cells were stained for morphological analysis whereas expression of chondrocyte markers including collagen type II and aggrecan were determined using reverse transcriptase-polymerase chain reaction. The polymer gel was not cytotoxic because the cell number retrieved from three-dimensional culture gel was found to be one to two times higher than that retrieved from monolayer culture. Chondrocytes propagated in the thermo-reversible polymers expressed enhanced or maintained expression of collagen type II and aggrecan. Collagen type I expression was decreased or unaltered. The N-isopropylacrylamide and acrylic acid copolymer gel has potential use as a cell culture substrate and as a cell delivery vehicle.

Procoagulants and osteonecrosis

OBJECTIVE

To study the relationship between hypofibrinolysis, thrombophilia, and osteonecrosis. We evaluated the frequency of abnormal concentrations of 9 coagulation factors in patients diagnosed with osteonecrosis.

METHODS

Blood samples were drawn from 45 patients diagnosed with osteonecrosis. Etiologic associations included systemic lupus erythematosus (n = 9), inflammatory bowel disease (n = 1), corticosteroid therapy (n = 20), or history of heavy alcohol (n = 4) or tobacco (n = 3) use. No associated risk factors were identified in 5 patients; these individuals were labeled "idiopathic." The patient cohort was matched to a similarly studied cohort of 40 healthy individuals without documented osteonecrosis. The following factors were analyzed: plasminogen activator inhibitor (PAI-Fx), stimulated tissue plasminogen activator, lipoprotein (a), resistance to activated protein C, anticardiolipin antibodies (aCL IgG, IgM), protein C, protein S (free), and homocysteine.

RESULTS

Thirty-seven of the 45 patients (82.2%) with osteonecrosis were found to have at least one coagulopathy, versus 30% of controls (p < 0.0001). Twenty-one patients (46.7%) were identified with 2 or more abnormal test results versus 2.5% of controls (p < 0.0001). Patients were more likely than controls to have high levels of the hypofibrinolytic plasminogen activator inhibitor activity (42% vs 3%; p < 0.0001), and high anticardiolipin antibody IgG (34% vs 10%; p = 0.008). At least one coagulation factor abnormality was detected in all 5 idiopathic patients; elevated aCL IgG and PAI-Fx were evident in 4 patients.

CONCLUSION

This study revealed a high incidence of thrombophilic and hypofibrinolytic coagulation abnormalities in patients with osteonecrosis. These findings have major implications for the diagnosis as well as the treatment of this disease. Since some of these abnormalities may be the result of autosomal dominant disorders, it may be possible to detect individuals at risk for development of this disease.