Thorsten M. Seyler

BLyS and APRIL in rheumatoid arthritis

The cytokines B lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL) enhance autoimmune disease by sustaining B cell activation. In RA, B cells contribute to the formation of 3 functionally distinct types of lymphoid microarchitectures in the inflamed synovium: ectopic GCs; T cell-B cell aggregates lacking GC reactions; and unorganized, diffuse infiltrates. We examined 72 tissues representing the 3 types of synovitis for BLyS and APRIL production and for expression of APRIL/BLyS receptors. Biologic effects of BLyS and APRIL were explored by treating human synovium-SCID mouse chimeras with the APRIL and BLyS decoy receptor transmembrane activator and CAML interactor:Fc (TACI:Fc). GC+ synovitis had the highest levels of APRIL, produced exclusively by CD83+ DCs. BLyS was present in similar levels in all tissue types and derived exclusively from CD68+ macrophages. In GC+ synovitis, treatment with TACI:Fc resulted in GC destruction and marked inhibition of IFN-gamma and Ig transcription. In contrast, inhibition of APRIL and BLyS in aggregate and diffuse synovitis left Ig levels unaffected and enhanced IFN-gamma production. These differential immunomodulatory effects correlated with the presence of TACI+ T cells in aggregate and diffuse synovitis and their absence in GC+ synovitis. We propose that BLyS and APRIL regulate B cell as well as T cell function and have pro- and antiinflammatory activities in RA.

Hip resurfacing arthroplasty.

Abstract Hip resurfacing arthroplasty is a type of hip replacement that involves capping the femoral head and preserving bone of the proximal femur. Metal‐on‐metal surface replacements have been manufactured since the early 1990s. Recent studies indicate excellent clinical results with low failure rates at 1‐ to 5‐year follow‐up. Although these early results are encouraging, resurfacing devices must be used with caution because less is known about their long‐term safety and efficacy. The best candidates for resurfacing are patients younger than age 60 years with good bone stock. The surgical approach is similar to that for standard total hip replacements, but with slightly more dissection because the femoral head must be preserved and displaced to visualize the acetabulum. To reduce complications, resurfacing arthroplasty should be performed by surgeons who have received training specifically in this technique.

Effect of changing indications and techniques on total hip resurfacing.

Recently, improved metal-on-metal bearing technology has led to the reemergence of resurfacing as a reasonable option for total hip arthroplasty. During the course of a prospective multicenter FDA-IDE evaluation of metal-on-metal total hip resurfacings, we modified our indications and emphasized surgical technique where the femoral surface area was small due to femoral cysts and small component size. We assessed the influence of these changes on complication rates in the first cohort of 292 patients and the second of 724, and then compared these outcomes in the second cohort with historical reports of resurfacing. We had a minimum followup of 24 months (mean, 33 months; range, 24-60 months). After changes were made in the indications and technique, the overall complication rate decreased from 13.4% to 2.1% with the femoral neck fracture rate reduced from 7.2% to 0.8%. The outcomes of the second cohort compare with modern-day resurfacing devices and appear superior to historical results. The data suggest patients should be carefully selected and technique optimized to reduce complications. Long-term followup is required to see if these promising results will be maintained.Level of Evidence: Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Use of metal-on-metal total hip resurfacing for the treatment of osteonecrosis of the femoral head.

BACKGROUND Recently, with the advent of improved metal-on-metal prostheses, total hip resurfacing has emerged as a viable arthroplasty option. However, it remains controversial whether this procedure should be used in patients with osteonecrosis when the femoral resurfacing component is cemented onto dead bone. The purpose of this study was to analyze the clinical and radiographic outcomes of metal-on-metal total hip resurfacing arthroplasty in patients with osteonecrosis of the femoral head. In addition, this group was compared with a matched group of patients who were diagnosed as having osteoarthritis. METHODS Forty-two osteonecrotic hips that were treated with a metal-on-metal total hip resurfacing arthroplasty were studied. They were matched by gender, age, prosthesis, surgeon, and surgical approach to forty-two osteoarthritic hips that were treated with the same metal-on-metal prosthesis. In the osteonecrosis group, there were twenty-five men and eleven women, and in the osteoarthritis group, there were twenty-eight men and thirteen women. The mean age at the time of surgery was forty-two years. Patients were followed both clinically and radiographically for a mean of forty-one months. RESULTS The clinical outcomes were similar for both groups, with a good or excellent outcome in thirty-nine hips (93%) with osteonecrosis and a good or excellent outcome in forty-one hips (98%) with osteoarthritis. In each of the two groups, there were two failures that required conversion to a standard total hip arthroplasty. Survivorship curves were similar for the two patient groups. CONCLUSIONS The short-term results for metal-on-metal total hip resurfacing for this challenging patient population with osteonecrosis were excellent and comparable with those seen in patients with osteoarthritis. We await long-term results to see if these early results are maintained. LEVEL OF EVIDENCE Prognostic Level II. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Prevalence of rotator cuff tear in paraplegic patients compared with controls.

BACKGROUND Musculoskeletal injuries of the shoulder in paraplegic patients with long-term survival can result from overuse and/or inappropriate use of wheelchairs. The purpose of the present study was to evaluate the prevalence and risk of pathological changes in the weight-bearing shoulder girdle of paraplegic patients who have been wheelchair-dependent for more than thirty years in comparison with able-bodied volunteers. METHODS One hundred paraplegic patients were matched for sex and age with a group of 100 able-bodied volunteers. Two hundred shoulders from each group were evaluated with use of magnetic resonance imaging. Collected outcome measures included a standardized clinical examination protocol, the Constant score, and a visual analog score for pain intensity. RESULTS Shoulder function according to the Constant score was significantly worse in the paraplegic patients than in the able-bodied volunteers. Similarly, the visual analog scale pain scores were significantly worse for the paraplegic patients. Magnetic resonance imaging showed that the prevalence of rotator cuff tears in either shoulder was significantly higher in the paraplegic patients than in the able-bodied volunteers (63% compared with 15%), resulting in a tenfold higher risk of rotator cuff rupture among paraplegic patients. CONCLUSIONS The present study demonstrates that the structural and functional changes of the shoulder joint are more severe and the risk of development of shoulder girdle damage is significantly higher in individuals with long-term paraplegia than in age-matched controls.

Instability after total hip arthroplasty: treatment with large femoral heads vs constrained liners.

One of the most common complications after total hip arthroplasty is instability. This study reviewed the recent literature concerning the indications, contraindications, and results of recent studies using both constrained liners and large femoral heads to treat instability after total hip arthroplasty. We also report on the results of a series of 41 patients (52 hips) considered being at high risk for dislocation who were treated with large-diameter metal-on-metal bearings and who were compared with a matched group of hips treated with standard-size metal-on-polyethylene bearings. The large-diameter femoral head group had no dislocations at a minimum follow-up of 24 months, whereas the standard-size group had 2 dislocations. We support the use of large femoral heads to treat instability in a wide variety of patients because of the increased stability, decreased wear of modern metal-on-metal designs, increased range of motion, and variety of revision options.

Repeated botulinum-A toxin injections in the treatment of myelodysplastic children and patients with spinal cord injuries with neurogenic bladder dysfunction

Authors from Germany describe the use of botulinum toxin in the treatment of myelodysplastic children and found it to be safe and effective. They found that repeat treatments are as effective as the first one, with no evidence of tachyphylaxis, antibody formation or detrusor fibrosis.

Treatment of early stage osteonecrosis of the femoral head.

Osteonecrosis is a devastating disease that primarily affects weight-bearing joints. The hip is the most commonly affected joint. Although hip osteonecrosis can affect patients of any age group, it typically presents in young patients between the ages of twenty and forty years1. The factors that affect the progression of this disease are still not fully understood, but radiographic lesion size, femoral head collapse (if present), and, occasionally, clinical presentation at the time of diagnosis have been shown to be predictive of the eventual clinical outcome2,3. After collapse, most patients will require a standard total hip arthroplasty4,5. However, because of the young age of many of these patients, a hip replacement cannot be expected to last the patients lifetime and therefore, when feasible, attempts should be made to save the femoral head prior to collapse with use of less invasive treatment modalities. The efficacy of these procedures has been variable, with reported success rates ranging between 60% and 80% at the time of short-term and midterm follow-up6-8. Current treatments range from pharmacotherapies to surgical interventions that include core decompression, vascularized or nonvascularized bone-grafting, and osteotomy. Recently there have been attempts to enhance these surgical techniques with use of various growth and differentiation factors. The primary purpose of this report is threefold: (1) to discuss the importance of early diagnosis and the standards for identifying and staging osteonecrosis; (2) to assess the efficacy of various treatment modalities and techniques by conducting an extensive literature review and comparing reported outcomes with those of patients treated at our institution; and (3) to provide a recommended treatment algorithm based on the assessment of these treatment options. All patients who were treated at our institution for early stage osteonecrosis of the hip …

Uncemented Total Hip Arthroplasty In Young Adults With Osteonecrosis Of The Femoral Head: A Comparative Study

BACKGROUND The outcome of uncemented total hip arthroplasty in patients with osteonecrosis of the femoral head in general, and in young adults in particular, remains largely unknown. This study evaluated the clinical and radiographic results of uncemented total hip arthroplasty in young adults with osteonecrosis of the femoral head and compared these results to those seen in young adults with osteoarthritis. METHODS Forty-one consecutive patients with osteonecrosis of the femoral head (fifty-two hips) and forty patients with osteoarthritis (fifty-two hips) were treated with an uncemented total hip arthroplasty at our institution. The mean age for the osteonecrosis group was thirty-eight years, and, for the osteoarthritis group, forty-two years. Clinical and radiographic outcomes at a minimum of two years were assessed. RESULTS At a mean duration of follow-up of three years, the functional improvement was significant in both groups (p < 0.05). The outcome was good to excellent for 94% (forty-nine hips) in the osteonecrosis group and 96% (fifty hips) in the osteoarthritis group. There were two revisions in the osteonecrosis group and one revision in the osteoarthritis group. Survivorship free of revision at the time of the latest follow-up was 96.1% for the osteonecrosis group and 98% for the osteoarthritis group. CONCLUSIONS The short-term results of cementless total hip arthroplasty in patients with osteonecrosis of the femoral head were encouraging and comparable with the results of a matched group of patients with osteoarthritis. We await further follow-up to see if these promising results hold true. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Robotic systems in orthopaedic surgery

Robots have been used in surgery since the late 1980s. Orthopaedic surgery began to incorporate robotic technology in 1992, with the introduction of ROBODOC, for the planning and performance of total hip replacement. The use of robotic systems has subsequently increased, with promising short-term radiological outcomes when compared with traditional orthopaedic procedures. Robotic systems can be classified into two categories: autonomous and haptic (or surgeon-guided). Passive surgery systems, which represent a third type of technology, have also been adopted recently by orthopaedic surgeons. While autonomous systems have fallen out of favour, tactile systems with technological improvements have become widely used. Specifically, the use of tactile and passive robotic systems in unicompartmental knee replacement (UKR) has addressed some of the historical mechanisms of failure of non-robotic UKR. These systems assist with increasing the accuracy of the alignment of the components and produce more consistent ligament balance. Short-term improvements in clinical and radiological outcomes have increased the popularity of robot-assisted UKR. Robot-assisted orthopaedic surgery has the potential for improving surgical outcomes. We discuss the different types of robotic systems available for use in orthopaedics and consider the indication, contraindications and limitations of these technologies.