Good implant survival after acetabular revision with extensive impaction bone grafting and uncemented components.

AIMS: This single-centre observational study aimed to describe the results of extensive bone impaction grafting of the whole acetabular cavity in combination with an uncemented component in acetabular revisions performed in a standardized manner since 1993. METHODS: Between 1993 and 2013, 370 patients with a median age of 72 years (interquartile range (IQR) 63 to 79 years) underwent acetabular revision surgery. Of these, 229 were more than ten years following surgery and 137 were more than 15 years. All revisions were performed with extensive use of morcellized allograft firmly impacted into the entire acetabular cavity, followed by insertion of an uncemented component with supplementary screw fixation. All types of reoperation were captured using review of radiographs and medical charts, combined with data from the local surgical register and the Swedish Hip Arthroplasty Register. RESULTS: Among patients with possible follow-up of ten and 15 years, 152 and 72 patients remained alive without revision of the acetabular component. The number of deaths was 61 and 50, respectively. Of those who died, six patients in each group had a reoperation performed before death. The number of patients with a reoperation was 22 for those with ten-year follow-up and 21 for those with 15 years of follow-up. The Kaplan-Meier implant survival rate for aseptic loosening among all 370 patients in the cohort was 96.3% (95% confidence interval (CI) 94.1 to 98.5) after ten years and 92.8% (95% CI 89.2 to 96.6) after 15 years. CONCLUSION: Extensive bone impaction grafting combined with uncemented revision components appears to be a reliable method with favourable long-term survival. This technique offers the advantage of bone stock restoration and disputes the long-standing perception that uncemented components require > 50% of host bone contact for successful implant survival. Cite this article: Bone Joint J 2020;102-B(2):198-204.

No Difference in Periprosthetic Bone Loss and Fixation Between a Standard-Length Stem and a Shorter Version in Cementless Total Hip Arthroplasty. A Randomized Controlled Trial.

BACKGROUND: Cementless femoral stems in total hip arthroplasty provide dependable clinical and radiographic results in the treatment of osteoarthritis. Stem length might affect the preservation of proximal bone stock and stability. We hypothesized that a shorter stem decreases proximal bone loss without affecting implant stability. METHODS: We randomly assigned 60 patients aged between 50 and 70 years to either a standard cementless femoral stem or a 35-mm shorter version. Patients were followed with dual-energy X-ray absorptiometry, radiostereometric analysis, Harris hip score, Western Ontario and McMaster Universities Osteoarthritis Index score, and clinical follow-up at 3, 6, 12, and 24 months. The trial is registered on ClinicalTrials.gov/. RESULTS: After 24 months, short stems had on average 3.8% (95% confidence interval, 1.2%-8.9%) more bone loss in zone 1 compared to standard stems (P = .14). In zone 7, the bone loss was on average 6.5% (95% confidence interval, 6.6%-19.7%) higher compared to standard stems (P = .33). After 24 months, standard stems had migrated 0.93 mm (range, 0.25-4.66 mm) and short stems 0.93 mm (range, 0.17-2.96 mm; Student t-test after log transformation, P = .3). Patient-reported outcome measures were similar in both groups. One patient in the standard stem group was diagnosed with infection, one with a posterior dislocation, and one with a deep venous thrombosis. No stems were revised. CONCLUSION: There were no statistically significant differences in periprosthetic bone loss or fixation between the stems at 24 months.

Acetabular revision with extensive allograft impaction and uncemented hydroxyapatite-coated implants. Results after 9 (7-11) years follow-up.

This is a clinical and radiographic review of 87 hips in 79 patients 9 (7-11) years after acetabular revision with extensive use of morselized allograft firmly impacted into localized defects as well as the entire acetabular cavity, followed by insertion of an uncemented hydroxyapatite-coated cup with supplementary screw fixation. The 9-year survival rate for the acetabular implant was 90.5% (95% CI, 83.4%-97.6%) with revision for any reason as end point and 94% (95% CI, 89%-99.1%) with revision for aseptic loosening as end point. Acetabular revision with massive allograft impaction and hydroxyapatite-coated implants show very promising results. The limited contact between implant and host bone does not seem to compromise implant survival in the 7- to 11-year perspective.

No difference in migration or wear between cemented low-profile cups and standard cups : a randomized radiostereographic study of 53 patients over 3 years.

BACKGROUND: Minor design changes may cause major changes in implant performance. Thus, as part of a stepwise introduction of a new low-profile cup, we performed a randomized trial comparing it to a well-documented standard cup. PATIENTS AND METHODS: 60 patients, stratified according to sex, weight, and age, underwent cemented total hip arthroplasty using a Lubinus SP2 stem with ceramic head and were randomized to either the new low-profile Lubinus Flanged Anti-Luxation cup (FAL) or the Lubinus Standard Eccentric cup (Standard). 7 patients were excluded and 53 (28 FAL) were evaluated at 3, 6, 12, and 36 months postoperatively. Primary outcome variables, cup migration (MTPM), and wear (total 3-dimensional femoral head penetration) were measured with radiostereometry (RSA). Clinical outcome was evaluated with the western Ontario and McMaster osteoarthritis index (Womac) and the visual analog pain score (VAS). RESULTS: We found no difference in migration between the FAL and Standard cups. There was no difference in wear between the two cups and there was no correlation between wear and migration. 3 cups (2 FAL and 1 Standard) showed continuous migration of a magnitude that indicated an increased risk of early loosening. Clinical outcome was excellent, without any difference between the 2 groups.

Hydroxyapatite coating improves 8- to 10-year performance of the link RS cementless femoral stem.

In a prospective randomized clinical study, 12 hydroxyapatite (HA)-coated and 8 identical but non-coated stems were implanted in 20 patients. At 8- to 10-year follow-up, the HA-coated stems displayed excellent clinical and radiographic results in 11 out of 12 patients, whereas 7 out of 8 non-coated stems were failures and had been subject to revision. Despite the small number of patients in this series, HA coating seems to improve the long-term stable fixation of uncemented femoral implants.