Radiological Demarcation of Cemented Sockets in Total Hip Replacement

Background Mid-head resection total hip resurfacing arthroplasty was promoted as an alternative to traditional total hip resurfacing for patients with poor femoral head bone quality or abnormal femoral head morphology, because those patients are at high risk of failure with traditional total hip resurfacing. It is a large-headed metal-onmetal device that uses a short, bone-conserving stem. Good performance of the implant has been reported at short-term followup, but no information on the implant performance in the mid-or long-term is available. Questions/purposes In this study, we report (1) on the mid-term implant survivorship and hip scores in a single nondesigner surgeon series. Because of the occurrence of femoral neck osteolysis and pseudotumor in a subgroup of patients, we also investigated the following: (2) Were there any preoperative parameters that are associated with osteolysis? (3) Could we differentiate the osteolysis group from the others on the basis of implant component sizes, positions, and radiologic parameters? (4) Could we differentiate the osteolysis group from the others on the basis of metal ion levels? Methods Between 2006 and 2011, one surgeon performed a total of 49 Birmingham Mid-head Resection total hip resurfacing arthroplasties in 47 patients. The general indications for this procedure were young patients who were considered suitable for hip resurfacing arthroplasty but had avascular necrosis, large cysts, or severe deformity of the femoral head. Clinical followup including Oxford Hip Score (OHS) and UCLA hip scores were available preoperatively and at a mean of 6 years (range, 3-8 years) on all patients (100%), radiographic followup on 45 of 47 (96%), MRIs on 18 (38%), and metal ion levels on 37 (79%). Mean age at surgery was 50 years. Spearman's correlation was used to test the association between femoral neck osteolysis and preoperative parameters, implant component sizes and positions, and blood metal ion levels. Results We found 100% survival. Patients' median OHS was 46 of 48 (range, 35-48) and UCLA 8 of 10 (range, 4-10). However, 16% of the hips (seven of 45) demonstrated osteolysis in the femoral neck. Of the preoperative parameters, the osteolysis was associated with low weight (r = À0.337, p = 0.031) and to a lesser degree with female sex (r = 0.275, p = 0.067). Radiologically, the osteolysis was strongly associated with the presence of a

Section: Methodsmentioning

confidence: 99%

Section: Survivorship and Hip Scoresmentioning

confidence: 99%

Frequent Femoral Neck Osteolysis With Birmingham Mid-head Resection Resurfacing Arthroplasty in Young Patients

Asaad

Hart

Khoo

et al. 2015

“…Future research might correlate radiographic signs with histologic and mechanical parameters to create a grading scale for osseointegration, which could have a similar clinical relevance to total joint arthroplasty grading systems [4,6,10,19]. Clinical applications of this approach might include assessment of whether implant design intentions are being met in animal translational studies and human preclinical trials.…”

Section: Discussionmentioning

confidence: 99%

Radiographic Evaluation of Bone Adaptation Adjacent to Percutaneous Osseointegrated Prostheses in a Sheep Model

Jeyapalina

Beck

Bachus

et al. 2014

Background Percutaneous osseointegrated prostheses (POPs) are being investigated as an alternative to conventional socket suspension and require a radiographic followup in translational studies to confirm that design objectives are being met. Questions/purposes In this 12-month animal study, we determined (1) radiographic signs of osseointegration and (2) radiographic signs of periprosthetic bone hypertrophy and resorption (adaptation) and (3) confirmed them with the histologic evidence of host bone osseointegration and adaptation around a novel, distally porous-coated titanium POP with a collar. Methods A POP device was designed to fit the right metacarpal bone of sheep. Amputation and implantation surgeries (n = 14) were performed, and plane-film radiographs were collected quarterly for 12 months. Radiographs were assessed for osseointegration (fixation) and bone adaptation (resorption and hypertrophy). The cortical wall and medullary canal widths were used to compute the cortical index and expressed as a percentage. Based on the cortical index changes and histologic evaluations, bone adaptation was quantified. Results Radiographic data showed signs of osseointegration including those with incomplete seating against the collar attachment. Cortical index data indicated distal cortical wall thinning if the collar was not seated distally. When implants were bound proximally, bone resorbed distally and the diaphyseal cortex hypertrophied. Conclusions Histopathologic evidence and cortical index measurements confirmed the radiographic indications of adaptation and osseointegration. Distal bone loading,

“…These were assessed independently by two reviewers (MDS, SAH) for the presence of progressive radiolucent lines at the acetabular bone-prosthesis interface in the zones described by DeLee and Charnley [11] and at the femoral bone-prosthesis interface in the zones described by Gruen et al [17]. Periprosthetic radiolucencies were considered clinically important if they were greater than 2 mm [26].…”

Section: Methodsmentioning

confidence: 99%

Custom Cementless THA in Patients with Skeletal Dysplasia Results in Lower Apparent Revision Rates than Other Types of Femoral Fixation

Sewell

Hanna

Muirhead-Allwood

et al. 2011

Background Patients with skeletal dysplasia are prone to degenerative hip disease thus requiring THA at a younger age than the general population. This is a technically demanding procedure with high complication and revision rates. Achieving good femoral fixation can be challenging because of the abnormal features of the hip. Questions/purposes We therefore determined: (1) survivorship, (2) function, (3) radiographic findings, and (4) complications associated with a cementless custommade femoral component used in THAs for patients with skeletal dysplasia and compared these parameters with those from other types of femoral fixation. Patients and Methods Between 1992 and 2005, 40 THAs were performed in 25 patients with skeletal dysplasia using custom-made cementless femoral components. There were 15 men and 10 women with a mean age of 37.5 years (range, 18-61 years) and a mean height of 145 cm (range, 120-173 cm). Patients were followed clinically and radiographically for a minimum of 4.3 years (mean, 10.1 years; range, 4.3-18.2 years). ResultsThe survivorship rates for the femoral and acetabular components were 92% and 70%, respectively, at 220 months. Revision arthroplasty was performed in four of 40 hips (10%). In two, the acetabular component was revised for aseptic loosening, one had both components revised for aseptic loosening, and one had an isolated femoral component revision for deep infection. The mean Harris hip score improved from 41 (range, 27-57) preoperatively to 80 (range, 51-94) at final followup. There were two intraoperative proximal femoral fractures and one dislocation. Conclusions When compared with studies with equal followup, custom-made cementless components in THAs for patients with skeletal dysplasia apparently had lower revision and complication rates with comparable function and higher midterm survival.