Midterm survivorship of a press-fit, plasma-sprayed, tri-spike acetabular component.

Press-fit acetabular cups without screw holes can limit migration of particulate wear debris and reduce risk of acetabular osteolysis and device loosening. The Tri-Spike cup (Biomet, Inc, Warsaw, Ind) includes a titanium alloy plasma spray porous surface and does not require screw fixation. We retrospectively examined the incidence of cup loosening and acetabular osteolysis after implantation of 45 cups (44 patients) with mean follow-up of 7.3 years (range, 4-9 years). Only one patient (one cup) had evidence of less than 1 mm of retroacetabular radiolucency at 3 years (nonprogressive), which was found to remain firmly fixed during revision of the aseptically loosened femoral component. No cups were removed or revised at latest follow-up. Projected Kaplan-Meier survivorship at 9 years was 100% for cup loosening/revision and 97.8% for radiolucency.

Prosthetic joint infections present diverse and unique microbial communities using combined whole-genome shotgun sequencing and culturing methods.

Introduction. Prosthetic joint infections (PJIs) are challenging to treat therapeutically because the infectious agents often are resistant to antibiotics and capable of abundant growth in surface-attached biofilms. Though infection rates are low, ca. 1-2 %, the overall increase in the sheer number of joint replacement surgeries results in an increase in patients at risk.Aims. This study investigates the consensus of microbial species comprising PJI ecology, which is currently lacking.Methodology. In this study, PJI populations from seven patients were analysed using combined culturing and whole-genome shotgun sequencing (WGSS) to establish population profiles and compare WGSS and culture methods for detection and identification of the PJI microbiome.Results. WGSS detected strains when culture did not, notably dormant, culture-resistant and rare microbes. The CosmosID algorithm was used to predict micro-organisms present in the PJI and discriminate contaminants. However, culturing indicated the presence of microbes falling below the WGSS algorithm threshold. In these instances, microbes cultured are believed to be minor species. The two strategies were combined to build a population profile.Conclusions. Variability between and among PJIs showed that most infections were distinct and unique. Comparative analysis of populations revealed PJIs to form clusters that were related to, but separate from, vaginal, skin and gut microbiomes. Fungi and protists were detected by WGSS, but the role of fungi is just beginning to be understood and for protists it is unknown. These micro-organisms and their novel and strain-specific microbial interactions remain to be determined in current clinical tests.

The cyclops lesion after bicruciate-retaining total knee replacement.

The cyclops lesion is a localized anterior arthrofibrosis most commonly seen following anterior cruciate ligament reconstruction. The lesion forms at the anterior cruciate ligament insertion creating a painful extension block between femoral intercondylar notch and tibial plateau. We present 2 cases (3 knees) in which cyclops lesions appeared atypically following bicruciate-retaining total knee replacement. Two lesions occurred in a single patient following bilateral knee replacement. One lesion occurred in an active sportswoman. All 3 resolved following arthroscopic debridement. We describe the presentation of this unusual complication and suggest keys to its diagnosis, treatment, and prevention.

An Autologous Anti-Inflammatory Protein Solution Yielded a Favorable Safety Profile and Significant Pain Relief in an Open-Label Pilot Study of Patients with Osteoarthritis.

Osteoarthritis (OA) is a progressive and degenerative disease, which may result in significant pain and decreased quality of life. Recent updates in our understanding of OA have demonstrated that it is a whole joint disease that has many similarities to an unhealed wound containing inflammatory cytokines. The nSTRIDE Autologous Protein Solution (APS) Kit is a medical device under development for the treatment of OA. The APS Kit processes a patient's own blood at the point of care to contain high concentrations of anti-inflammatory cytokines and anabolic growth factors. This study assessed the safety and treatment effects of a single intra-articular injection of APS. Eleven patients were enrolled in this study. Sufficient blood could not be drawn from one patient who was subsequently withdrawn, leaving 10 patients treated. Minor adverse events (AEs) were experienced by seven subjects (63.6%). There was one serious AE (diverticulitis) unrelated to the device or procedure. One subject experienced AEs that were judged "likely" to be procedure related (arthralgia/musculoskeletal discomfort) and all resolved within 6 days of injection. All other AEs were unrelated to the device or procedure. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scores improved significantly over time (ANOVA, p < 0.0001, 12.0 ± 1.2 preinjection, 3.3 ± 2.9 one year postinjection, and 72.5% WOMAC pain improvement). There was significant positive correlation between white blood cell concentration in APS and improvement in WOMAC pain scores.

Autologous protein solution prepared from the blood of osteoarthritic patients contains an enhanced profile of anti-inflammatory cytokines and anabolic growth factors.

The objective of this clinical study was to test if blood from osteoarthritis (OA) patients (n = 105) could be processed by a device system to form an autologous protein solution (APS) with preferentially increased concentrations of anti-inflammatory cytokines compared to inflammatory cytokines. To address this objective, APS was prepared from patients exhibiting radiographic evidence of knee OA. Patient metrics were collected including: demographic information, medical history, medication records, and Knee Injury and Osteoarthritis Outcome Score (KOOS) surveys. Cytokine and growth factor concentrations in whole blood and APS were measured using enzyme-linked immunosorbent assays. Statistical analyses were used to identify relationships between OA patient metrics and cytokines. The results of this study indicated that anti-inflammatory cytokines were preferentially increased compared to inflammatory cytokines in APS from 98% of OA patients. APS contained high concentrations of anti-inflammatory proteins including 39,000 ± 20,000 pg/ml IL-1ra, 21,000 ± 5,000 pg/ml sIL-1RII, 2,100 ± 570 pg/ml sTNF-RI, and 4,200 ± 1,500 pg/ml sTNF-RII. Analysis of the 82 patient metrics indicated that no single patient metric was strongly correlated (R(2) > 0.7) with the key cytokine concentrations in APS. Therefore, APS can be prepared from a broad range of OA patients.

Platelet-rich plasma application and heterotopic bone formation following total hip arthroplasty.

Activated blood platelets play a critical, early role in the wound healing response by releasing several types of growth factors at the site of injury which mediate the initial stages of tissue repair. Autologously derived platelet-rich plasma has been applied during surgery as a healing aid and some studies have shown benefit with total joint arthroplasty procedures such as in the knee. However, little has been published regarding the use of platelet-rich plasma during total hip arthroplasty. The hip is especially prone to develop islands of heterotopic bone following arthroplasty which can lead to pain, limited motion, and even ankylosis of the joint. If this condition is exacerbated by platelet-rich plasma, this could present a barrier to the use of this adjuvant in total hip arthroplasty. This retrospective, controlled clinical study examined the effect of platelet rich plasma application during closure following total hip arthroplasty on heterotopic ossification. By one year, 21.3% of the control patients developed heterotopic bone (91 patients, 94 hips, Brooker grades I-III) compared to 12.9% of the treatment patients (76 patients, 85 hips, Brooker grades I-II). These differences were not significant (p = 0.478, power = 0.90). Thus, the use of platelet-rich plasma in this procedure does not appear to influence the incidence or severity of heterotopic ossification which should help to justify further clinical research to more fully understand whether this autologous blood product has a role in total hip arthroplasty.

The relationship between pre- and postoperative range of motion utilizing three cruciate-retaining total knee prostheses.

We prospectively examined the relationship between pre- and postoperative range of motion utilizing three cruciate retaining knees with various mechanical flexion potentials, i.e., two at about 130 degrees -135 degrees (one with posterior lip and the other without) and the third at about 140 degrees -145 degrees . All groups demonstrated mean flexion and range of motion of 116 degrees -122 degrees at one year. Combining data from the three cohorts, patients with the following preoperative flexion values achieved the indicated mean changes (increases) in flexion at one year: < 90 degrees flexion (Delta 23.6 degrees ), 91 degrees -105 degrees flexion (Delta 19.3 degrees ), and > 105 degrees flexion (Delta 1.8 degrees )). Postoperative improvement was inversely related to preoperative flexion. The high flex knee yielded the best improvement in range of motion (9.7 degrees increase) in the highest flex preoperative group compared to that of the other knees (-7.4 degrees to 2.9 degrees ). Hence, a high flex knee design seems to be important in high preoperative range of motion patients obtaining an increase in the postoperative range of motion rather than possible regression.