Aims

This study aimed to establish the optimal fixation methods for calcaneal tuberosity avulsion fractures with different fragment thicknesses in a porcine model.

Aims

The involvement of cyclin D1 in the proliferation of microglia, and the generation and maintenance of bone cancer pain (BCP), have not yet been clarified. We investigated the expression of microglia and cyclin D1, and the influences of cyclin D1 on pain threshold.

Aims

This study aimed, through bioinformatics analysis, to identify the potential diagnostic markers of osteoarthritis, and analyze the role of immune infiltration in synovial tissue.

Aims

The study aimed to determine whether the microRNA miR21-5p (MiR21) mediates temporomandibular joint osteoarthritis (TMJ-OA) by targeting growth differentiation factor 5 (Gdf5).

Wear and corrosion debris generated from total hip replacements (THR) can cause adverse local tissue reactions (ALTR) or osteolysis, often leading to premature implant failure. The tissue response can be best characterized by histopathological analysis, which accurately determines the presence of cell types, but is limited in the characterization of biochemical changes (e.g. protein conformation alteration). Fourier transform infrared micro-spectroscopy imaging (FTIRI) enables rapid analysis of the chemical structure of biological tissue with a high spatial resolution, and minimal additional sample preparation. The data provides the most information through multivariate method carried out by hierarchical clustering analysis (HCA).

It is the goal of this study to demonstrate the beneficial use of this multivariate approach in providing pathologist with biochemical information from cellular and subcellular organization within joint capsule tissue retrieved from THR patients.

Joint capsule tissue from 2 retrieved THRs was studied. Case 1: a metal-on-polyethylene THR, and Case 2: a dual modular metal-on-metal THR. Prior to FTIRI analysis, tissue samples were formalin-fixed paraffin-embedded and 5μm thick microtome sectioned samples were prepared and mounted on BaF₂ discs and deparaffinized. FTIRI data were collected using high-definition transmission mode (pixel size: ∼1.1 μm²). Hyperspectral images were exported to CytoSpec V2.0.06 for processing and reconstruction into pseudo-color maps based on cluster assignments.

Case 1 exhibited a strong presence of lymphocytes and macrophages (Fig. 1a). Since the process of taking second derivatives reduces the half width of the spectral peaks, it increases the sensitivity toward detecting shoulders or second peaks that may not be apparent in the raw spectra (Fig. 1b). Thus, areas occupied by lymphocytes and macrophages can be easily distinguished providing a fast tissue screening method. Here, HCA was able to distinguish macrophages and lymphocytes based on the infrared response, even in areas where both occurred intermixed. (Fig. 1c) The tissue in direct proximity to cells had a slightly altered collagenous structure. Case 1 also exhibited multiple glassy, green particles which can typically observed around THRs that underwent taper corrosion (Fig. 2a). HCA image was able to visualize and distinguish large CrPO₄ particles, embedded within fibrin exudate rich areas, collagenous tissue without inflammatory cells, and a nearby area with a strong macrophage presence and some finer CrPO₄ particles (Fig. 2d). Moreover, this method can not only locate macrophages, but distinguish particle-laden macrophages depending the type of particles within the cells. In Case 2 (Fig. 3a), clustering results (Fig. 3 b&c) are consistent with the fact that different particle types are associated with MoM bearing surface wear (Co rich particles), corrosion of the CoCrMo taper junctions (Cr-oxides and –phosphate), fretting of Ti-alloy dual modular tapers (Ti-oxides, Ti alloy particles), and even suture debris, which all occurred in this case. Although details of debris types are not available, specifications are possible by coupling other techniques.

The results demonstrate that multivariate FTIRI based spectral histopathology is a powerful tool to characterize the chemical structure and foreign body response within periprosthetic tissue, thus providing insights into the biological impact of different types of implant debris.

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Objective

To three-dimensionally reconstruct the proximal femur of DDH (Developmental dysplasia of the hip) and measure the related anatomic parameters, so that we could have a further understanding of the morphological variation of the proximal femur of DDH, which would help in the preoperative planning and prosthesis design specific for DDH.

The first 101 posterior cruciate retaining modular tibial components of a single design performed by a single surgeon in 75 patients were evaluated at a minimum 20-year follow-up. All components were fixed with cement. These patients had been prospectively followed at five-year intervals and evaluated clinically using Knee Society ratings and documenting any need for reoperation. Serial radiographs were evaluated for radiolucencies, osteolysis or component migration until the time of patient death or at minimum 20-year follow-up.

At minimum 20-year follow-up, five knees (5%) had required a revision operation. All revisions occurred greater than 10 years following the index procedures. Benefits of modularity (i.e. retention of the tibial tray) were utilized in three of five cases in this closely followed cohort. Survivorship from any revision was 90.8% at 20 years. For the 16 living patients with 22 knees, the average Knee Society Clinical and Functional scores were 91 and 59, respectively, and the average range of motion was 115 degrees.

When considering gamma irradiated in air polyethylene and a first generation locking mechanism were utilized, these results encourage the authors to continue to use modular tibial trays.

Purpose: To our knowledge, there are no 35 year follow-up studies of the Charnley total hip arthroplasty in the United States. The purpose of the study was to evaluate the results of a single surgeon series of primary Charnley total hip arthroplasties performed with cement at a minimum 35 year follow-up interval.

Method: Between July 1970 and April 1972, the senior author performed 330 Charnley total hip replacements with cement using a hand-packing cement technique. At minimum 35 years post-operatively, 13 patients (16 hips) were alive, with 1 patient (1 hip) lost to follow-up. Living patients were evaluated clinically with a standard terminology questionnaire, and WOMAC. Radiographic evaluation included loosening, lysis, and need for reoperation.

Results: After a minimum 35 year follow-up, only 25 (8%) acetabular components and 10 (3%) femoral components revised for aseptic loosening. For the 16 hips in living patients, 7 acetabular components (44%) and 2 femoral component (12%) were revised for aseptic loosening. Overall, 87% of the original prosthesis remains intact at the time of final follow-up, or at the time of the patient’s death. The average linear wear rate for all patients with minimum 10 year radiographic follow-up was 0.09 mm/year.

Conclusion: Our follow-up study at a minimum 35 years following Charnley total hip arthroplasty with cement demonstrates the remarkable durability of the procedure. As demonstrated in this study, the long term challenge has been revisions associated with bearing surface wear. This study should provide a benchmark for comparison to follow-up studies of other procedures and devices as they reach this interval of follow-up.

Purpose: The original AML prosthesis was fully coated and later the manufacturer switched it to 5/8ths coating. The second generation Prodigy femoral component was developed to return to full coating of the prosthesis and to provide a medial relief to decrease bone stress shielding. The purpose of this study was to evaluate the minimum ten year results using this device and to compare the results to the same surgeon’s results at 10 years using a first generation proximally coated device.

Method: 100 consecutive primary total hip replacements were performed by a single surgeon in 86 patients using the Prodigy (DePuy, Warsaw, Indiana) femoral component between 1994 and 1997. The components were mated with 80 HGI and 20 Duraloc acetabular components. Patients were evaluated with WOMAC ratings, need for revision and radiographic loosening. The same parameters had been evaluated at minimum 10-year follow-up for the same surgeon’s initial 100 consecutive PCA (Stryker, New Jersey) primary THR’s and were compared to the present series.

Results: At minimum 10 year follow-up, 71 patients with 83 hips were living. The average clinical follow-up for the living patients was 11 years (range 10 to 12 years) and the average radiographic follow-up was 9.2 years for this group (range 7–12 years). No femoral component was revised for loosening and all femoral components were bone ingrown on radiographs. 7 acetabular components required a liner exchange or revision for polyethylene wear. This compares favorably to the same surgeon’s 10 year results with the PCA where 6 femoral components were revised for wear or loosening and an additional 2 were radiographically loose.

Conclusion: The Prodigy femoral component demonstrated excellent durability at 10 years. With the newer cementless stems with a wide variety of sizes, femoral loosening is rarely a clinical problem.

Purpose: Few reports are available at minimum 15 year follow-up of cemented modular cruciate retaining TKA, especially where all polyethylene patella components were utilized. This paper addresses the questions “What is the durability of cemented modular cruciate retaining TKA with all polyethylene patella components at 15 years?” and “Did modular tibial trays demonstrate their utility in terms of the potential for less costly and less complex revisions?”

Method: 101 Press Fit Condylar TKA’s were performed consecutively over a 27 month interval and followed prospectively for a minimum of 15 years. The average age at surgery was 72 years. Clinical Knee Society scores, need for revision, radiographic evidence of loosening, and osteolysis were recorded. All patients were recalled at 5 year intervals.

Results: At minimum 15 year follow-up, 34 patients with 45 knees were living and 40 patients with 54 knees were deceased (one patient [2 knees] was lost to follow-up). 81% of living patients had 15 year radiographs. 6 knees were revised (all related to wear and osteolysis). Average Knee Society clinical scores only deteroriated from 92 points to 89 points between 10 and 15 years.

Conclusion: This cemented modular CR TKA performed well at 15 years with only 6% of knees requiring revision. All revisions occurred after 10 years and were related to wear and osteolysis. 2/3 of the revisions could be salvaged without tibial component revision in this closely followed series. Hopefully these results can be improved with better wear-resistant designs and better quality polyethylene. Especially into the second decade, patients with modular tibial tray TKA constructs should be closely followed to optimize their utility allowing less costly and less complex revisions in cases with polyethylene wear.

Purpose: Femoroacetabular impingement (FAI) is a precursor to osteoarthritis (OA) of the hip. To investigate the fate of impingement abnormalities we analyzed the contralateral hip in patients undergoing THA for advanced FAI. Our purpose was to determine the bilaterality of FAI abnormalities, and to describe the prognosis of these deformities.

Method: We reviewed 508 patients ≤50 years of age treated with THA. Radiographic review identified 70 hips that had OA secondary to FAI (71% cam, 5% pincer, 24% combined). Bilaterality was determined radiographically, and the fate of the contralateral hip was analyzed by determining radiographic presence and progression of OA, and the need for subsequent THA.

Results: 71% of the patients were male and the average age was 43.2 years. The contralateral hip was analyzed on radiographs over an average 9 year period (range, 4–30 years). 100% of the contralateral hips had radiographic features of FAI. 49 (70%) of the contralateral hips demonstrated degenerative disease. 14 had advanced OA at presentation, 41 had progressive joint space narrowing, 25 had progression of Tonnis OA grade and 26 underwent subsequent THA. Statistical analysis showed that alpha angle, LCEA, joint space width, and head-neck ratio have strong predictive value for subsequent THA (p< 0.05).

Conclusion: This study demonstrates that FAI abnormalities are commonly bilateral and are associated with OA progression in the majority of hips. Patients diagnosed with FAI should have both hips monitored, and joint preservation surgery or THA considered when appropriate.