Mansour Abolghasemian

Cementless fixation in total knee arthroplasty

In this study we present our experience with four generations of uncemented total knee arthroplasty (TKA) from Smith & Nephew: Tricon M, Tricon LS, Tricon II and Profix, focusing on the failure rates correlating with each design change. Beginning in 1984, 380 Tricon M, 435 Tricon LS, 305 Tricon 2 and 588 Profix were implanted by the senior author. The rate of revision for loosening was 1.1% for the Tricon M, 1.1% for the Tricon LS, 0.5% for the Tricon 2 with a HA coated tibial component, and 1.3% for the Profix TKA. No loosening of the femoral component was seen with the Tricon M, Tricon LS or Tricon 2, with no loosening seen of the tibial component with the Profix TKA. Regarding revision for wear, the incidence was 13.1% for the Tricon M, 6.6% for the Tricon LS, 2.3% for the Tricon 2, and 0% for the Profix. These results demonstrate that improvements in the design of uncemented components, including increased polyethylene thickness, improved polyethylene quality, and the introduction of hydroxyapatite coating, has improved the outcomes of uncemented TKA over time.

Nineteen year results of THA using modular 9 mm S-ROM femoral component in patients with small femoral canals.

A retrospective analysis was undertaken of 30 consecutive THA performed in 25 patients with hypoplastic proximal femurs, who had received a 9-mm uncemented modular S-ROM stem. The mean patient age was 42 years (17-69 years), mean height was 152.5 cm (130-170.5 cm), mean weight was 63 kg (39-90 kg), and mean follow-up period was 19 years (range, 12-23 years). Subsidence was seen in 2 hips, with asymptomatic femoral osteolysis present in 11 hips; overall survival of the femoral stem was 93.3%, with two revisions of the femoral component required for aseptic loosening. After a mean follow-up of 19 years, the use of the S-ROM 9 mm femoral stem in the patient with the small femur was associated with a low revision rate due to aseptic loosening of the stem.

A Long-Term Survivorship Comparison Between Cemented and Uncemented Cups With Shelf Grafts in Revision Total Hip Arthroplasty After Dysplasia

Long-term outcomes of cemented and uncemented cups were compared in patients with hip dysplasia who had undergone revision hip arthroplasty. Patients had uncontained superolateral acetabular defects reconstructed with a structural allograft. This retrospective study compared 18 cemented acetabular cups to 27 uncemented acetabular cups. Average follow-up was 216 months (range, 96-312). Nineteen acetabular cups (42%) failed due to loosening and were revised. The 10- and 20-year cup survival was 88% and 76% in the uncemented group and 67% and 36% in the cemented group. Log rank analysis showed this difference to be significant (P = .0077). Uncemented acetabular cups performed significantly better than cemented cups.

Management of massive acetabular bone defects in revision arthroplasty of the hip using a reconstruction cage and porous metal augment

AIMS It may not be possible to undertake revision total hip arthroplasty (THA) in the presence of massive loss of acetabular bone stock using standard cementless hemispherical acetabular components and metal augments, as satisfactory stability cannot always be achieved. We aimed to study the outcome using a reconstruction cage and a porous metal augment in these patients. PATIENTS AND METHODS A total of 22 acetabular revisions in 19 patients were performed using a combination of a reconstruction cage and porous metal augments. The augments were used in place of structural allografts. The mean age of the patients at the time of surgery was 70 years (27 to 85) and the mean follow-up was 39 months (27 to 58). The mean number of previous THAs was 1.9 (1 to 3). All patients had segmental defects involving more than 50% of the acetabulum and seven hips had an associated pelvic discontinuity. RESULTS Three failures were observed in two hips, both of which had undergone a previous resection of a tumour affecting the acetabulum. Other complications included a late arterial injury, a sciatic nerve palsy, a dislocation treated with a femoral revision, a deep infection treated with irrigation and debridement and a fracture of the greater trochanter treated conservatively. The mean Oxford Hip Score significantly increased from 13.9 (2 to 23) to 28.7 (13 to 38) (p < 0.00001). The mean vertical distance between the centre of rotation of the hip and its normal location decreased from 30 mm to 10 mm. CONCLUSIONS Acceptable early survivorship can be achieved using this novel technique, but it may be unsuitable for use in patients who have previously undergone the resection of a tumour involving the acetabulum. Cite this article: Bone Joint J 2017;99-B:607-13.

Salvaged failed roof rings and antiprotrusion cages: surgical options and implant survival

Introduction Failed acetabular reinforcement rings (ARR) (roof rings and antiprotrusion cages) may require another ARR reconstruction or another type of acetabular device with or without a bone graft. The purpose of this study was to propose surgical options for salvage of failed ARRs and to compare the failure rate of each surgical option. Materials and methods We reviewed 33 first ARRs (12 roof rings and 21 antiprotrusion cages) which were revised and converted to a new acetabular reconstruction. Operative reports, radiographs, and clinical data were evaluated. Minimum follow-up was 24 months (average 57 months; range 24-209 months). Results 33 failed first ARRs were converted to one of three types of acetabular reconstruction, Trabecular Metal (TM) cup in 14, cup-cage in 7 and a second ARR in 12. The TM cup group (TM cup and cup-cage) had a significantly longer survival than the second ARR group (P = 0.025) on log-rank analysis. Discussion Treatment of a failed first ARR by a TM cup and a cup-cage provides better results when compared to treatment by a second ARR. Restoration of bone stock is the main factor in determining whether a TM cup or cup-cage rather than another conventional ARR can be used.