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Background Pseudotumor-like periprosthetic tissue reactions around metal-on-metal (M-M) hip replacements can cause pain and lead to revision surgery. The cause of these reactions is not well understood but could be due to excessive wear, or metal hypersensitivity or an as-yet unknown cause. The tissue features may help distinguish reactions to high wear from those with suspected metal hypersensitivity. Questions/purposes We therefore examined the synovial lining integrity, inflammatory cell infiltrates, tissue organization, necrosis and metal wear particles of pseudotumor-like tissues from M-M hips revised for suspected high wear related and suspected metal hypersensitivity causes. Methods Tissue samples from 32 revised hip replacements with pseudotumor-like reactions were studied. A 10-point histological score was used to rank the degree of aseptic lymphocytic vasculitis-associated lesions (ALVAL) by examination of synovial lining integrity, inflammatory cell infiltrates, and tissue organization. Lymphocytes, macrophages, plasma cells, giant cells, necrosis and metal wear particles were semiquantitatively rated. Implant wear was measured with a coordinate measuring machine. The cases were divided into those suspected of having high wear and those suspected of having metal hypersensitivity based on clinical, radiographic and retrieval findings. The Mann-Whitney test was used to compare the histological features in these two groups. Results The tissues from patients revised for suspected high wear had a lower ALVAL score, fewer lymphocytes, but more macrophages and metal particles than those tissues from hips revised for pain and suspected metal hypersensitivity. The highest ALVAL scores occurred in patients who were revised for pain and suspected metal hypersensitivity. Component wear was lower in that group. Conclusions Pseudotumor-like reactions can be caused by high wear, but may also occur around implants with low wear, likely because of a metal hypersensitivity reaction. Histologic features including synovial integrity, inflammatory cell infiltrates, tissue organization, and metal particles may help differentiate these causes. Clinical Relevance Painful hips with periprosthetic masses may be caused by high wear, but if this can be ruled out, metal hypersensitivity should be considered.

BackgroundPeriprosthetic bone loss is a common observation following arthroplasty. Recognizing and understanding the nature of bone loss is vital as it determines the subsequent performance of the device and the overall outcome. Despite its significance, the term “bone loss” is often misused to describe inflammatory osteolysis, a complication with vastly different clinical outcomes and treatment plans. Therefore, the goal of this review was to report major findings related to vertebral radiographic bone changes around cervical disc replacements, mitigate discrepancies in clinical reports by introducing uniform terminology to the field, and establish a precedence that can be used to identify the important nuances between these distinct complications. MethodsA systematic review of the literature was conducted following PRISMA guidelines, using the keywords “cervical,” “disc replacement,” “osteolysis,” “bone loss,” “radiograph,” and “complications.” A total of 23 articles met the inclusion criteria with the majority being retrospective or case reports. ResultsFourteen studies reported periprosthetic osteolysis in a total of 46 patients with onset ranging from 15–96 months after the index procedure. Reported causes included: metal hypersensitivity, infection, mechanical failure, and wear debris. Osteolysis was generally progressive and led to reoperation. Nine articles reported non-inflammatory bone loss in 527 patients (52.5%), typically within 3–6 months following implantation. The reported causes included: micromotion, stress shielding, and interrupted blood supply. With one exception, bone loss was reported to be non-progressive and had no effect on clinical outcome measures.ConclusionsNon-progressive, early onset bone loss is a common finding after CDA and typically does not affect the reported short-term pain scores or lead to early revision. By contrast, osteolysis was less common, presenting more than a year post-operative and often accompanied by additional complications, leading to revision surgery. A greater understanding of the clinical significance is limited by the lack of long-term studies, inconsistent terminology, and infrequent use of histology and explant analyses. Uniform reporting and adoption of consistent terminology can mitigate some of these limitations. Executing these actionable items is critical to assess device performance and the risk of revision.Level of Evidence IVDiagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Purpose Anterior cruciate ligament (ACL) rupture is increasingly common in adolescents. Time between ACL rupture and surgical reconstruction, surgical wait time, is related to concurrent meniscal tear incidence and possibly tear pattern. This study defines the relationship between meniscal tear characteristics and surgical wait time in adolescents with ACL rupture. Methods One-hundred and twenty-one consecutive adolescent (median age 16.1 years, range 9–19 years) ACL rupture patients undergoing primary ACL reconstruction were studied. All had documented surgical wait time, preoperative and 6-month post-operative outcome (Lysholm and pedi-IKDC) scores, and intraoperative meniscus tear characteristics. Meniscal tear severity was graded according to the Lawrence and Anderson system: non-surgical: grade 1; reparable: grade 2–3; irreparable: grade 4–5. Significant tears were defined as at least grade 2. Results Average age at surgery was 16.1 years. 48.7 % had surgical wait time greater than 6 months. 42.5 % of menisci were torn. With surgical wait time <6 months, there were more lateral than medial tears (48 vs 21 %, p  = 0.001). With surgical wait time >6 months, medial tear incidence increased (50 vs 21 %, p  < 0.001), there were more significant tears (63 vs 42 %, OR 2.3, p  = 0.02), and preoperative Lysholm and pedi-IKDC scores were lower (58 vs 74, p  < 0.001; 52 vs 61, p  < 0.007). Scores were lower in patients with meniscus tears (63.8 vs 69.3, n.s.; 53.9 vs 60.5, p  = .04). Patients with public insurance had risks of surgical wait time greater than 3 months (OR 12.4, p  < 0.001) and 6 months (OR 7.8, p  < 0.001), and of a significant meniscus tear (OR 2.5, p  = 0.03). Six-month post-operative pedi-IKDC scores improved more in meniscus tear patients (28.4 vs 21, p  = 0.05). Conclusions This study shows a significant increase in medial meniscal tear incidence, decrease in preoperative scores, and worse tear severity with surgical wait time >6 months. Public insurance was a risk factor for longer surgical wait time and meniscus tear.

Purpose Composite models have become commonplace for the assessment of fixation and stability of total joint replacements; however, there are no comparable models for the cervical spine to evaluate fixation. The goal of this study was to create the framework for a tunable non‐homogeneous model of cervical vertebral body by identifying the relationships between strength, in‐fill density, and lattice structure and creating a final architectural framework for specific strengths to be applied to the model. Methods The range of material properties for cervical spine were identified from literature. Using additive manufacturing software, rectangular prints with three lattice structures, gyroid, triangle, zig‐zag, and a range of in‐fill densities were 3D‐printed. The compressive and shear strengths for all combinations were calculated in the axial and coronal planes. Eleven unique vertebral regions were selected to represent the distribution of density. Each bone density was converted to strength and subsequently correlated to the lattice structure and in‐fill density with the desired material properties. Finally, a complete cervical vertebra model was 3D‐printed to ensure sufficient print quality. Results Materials testing identified a relationship between in‐fill densities and strength for all lattice structures. The axial compressive strength of the gyroid specimens ranged from 1.5 MPa at 10% infill to 31.3 MPa at 100% infill and the triangle structure ranged from 2.7 MPa at 10% infill to 58.4 MPa at 100% infill. Based on these results, a cervical vertebra model was created utilizing cervical cancellous strength values and the corresponding in‐fill density and lattice structure combination. This model was then printed with 11 different in‐fill densities ranging from 33% gyroid to 84% triangle to ensure successful integration of the non‐homogeneous in‐fill densities and lattice structures. Conclusions The findings from this study introduced a framework for using additive manufacturing to create a tunable, customizable biomimetic model of a cervical vertebra. This manuscript addresses the lack of a biomechanically validated in vitro model for preclinical testing of cervical disc replacements. The results from this study introduced the first tunable, customizable, and nonhomogeneous biomimetic model of a cervical vertebral body.

The Orthopaedic Fellowship Match was established in 2008 to streamline and improve the process of matching residents and fellowships. The purpose of this study was to quantify the factors that affect the application process and to determine how residents establish a rank list. The Orthopaedic Fellowship Match has improved the ability of residents and programs to consider their options more carefully and to focus on finding the best match. However, this process introduces new factors for all parties involved to consider. The costs of the interview process and time away from service for residents may be larger than anticipated. Ultimately, residents value operative experience and staff members at a fellowship more than all other factors when selecting a fellowship. [The Orthopaedic Fellowship Match was established in 2008 to streamline and improve the process of matching residents and fellowships. The purpose of this study was to quantify the factors that affect the application process and to determine how residents establish a rank list. The Orthopaedic Fellowship Match has improved the ability of residents and programs to consider their options more carefully and to focus on finding the best match. However, this process introduces new factors for all parties involved to consider. The costs of the interview process and time away from service for residents may be larger than anticipated. Ultimately, residents value operative experience and staff members at a fellowship more than all other factors when selecting a fellowship. [ Orthopedics. 2015; 38(3):175–179.]

Background The use of hamstring autografts less than 8.0mmin size to reconstruct anterior cruciate ligament (ACL) injuries is associated with a higher risk of graft failure. A hybrid graft consisting of hamstring autograft tendons supplemented by allograft tendon to create a more robust graft has been proposed as an alternative treatment option in patients with small hamstring graft size. Multiple studies have shown inconsistent results for ACL reconstructions with hybrid grafts. This meta-analysis was designed to examine the rates of graft failure and clinical outcome measures for hybrid grafts in primary ACL reconstructions. Methods A search was performed of PubMed, MEDLINE and Google Scholar using the terms “Anterior Cruciate Ligament” OR “ACL” combined with “reconstruction” and “hybrid.” Two authors reviewed the papers, and outcomes were subdivided into autograft and hybrid graft. Chi Square with Yates Correction was used to determine the correlation between failure and type of graft for all patients, as well as for the subanalysis done for patients less than 18 years old and patients greater than 18 years old. Chi Square with Yates Correction and unpaired t-test were used to compare the demographic characteristics of the two groups. Unpaired t-test was used to evaluate for differences in subjective outcome scores. Results A total of 9 studies met the inclusion criteria. Only one study included a comparison of hybrid grafts with autografts and allografts, and as such, the allograft data was excluded from the analysis. Overall a total of 506 patients were treated with autografts with an average age of 26.7 +/- 10.8 years; and a total of 453 patients were treated with hybrid grafts with an average age of 28.33 +/-10.4 years. All patients had minimum follow up of 2 years with average follow up of 38.2 months. There was no significant difference in sex between the two groups (p = 0.07). There were significantly more females in the hybrid group compared to the autograft group (48% versus 42%, respectively p = 0.02). There was no significant difference in failure rates for the autograft or hybrid graft subgroups (p = 0.92). International Knee Documentation (IKDC) scores and Lysholm scores were significantly higher in the autograft group than the hybrid graft group (p = 0.02 and p < 0.01, respectively). There was no significant difference in Tegner Activity scores (p =0.68). On further subgroup analysis, there was no difference in failure rates for autografts vs hybrid grafts with subgroup analysis for both patients under 18 years of age and patients over 18 years of age (p = 0.78 and p = 0.24, respectively). Conclusions Supplementation of hamstring autograft with allograft tissue to form a “hybrid graft” did not alter the graft failure rate. But, the use of hybrid graft was associated with worse subjective outcome scores as measured by IKDC and Lysholm scores. Level of Evidence Level IV (A meta-analysis of Level II, III, and IV studies)