Background: In order to achieve a minimized need for tissue dissection resulting in a faster rehabilitation, minimally invasive surgery (MIS) in Total Hip Arthroplasty (THA) was developed. In this small incision technique the skin and musle dissection has been reduced with respect to the classical approach. Literature shows ambiguous results comparing the posterolateral minimally incisive with the classical approach. As the anterolateral approach is also a routine procedure, and to test how minimally invasive MIS is, we hypothesized that patients treated with a THA using a posterolateral or anterolateral MIS would experience improved clinical results compared with a standard incision after six weeks and no clinical differences after one year. This was tested in a double-blind randomized controlled trial with the Harris Hip Score (HHS) as a primary endpoint.

Methods: One hundred and twenty consecutive primary uncemented THAs were randomized into one of four groups of 30 patients each. Either standard posterolateral or anterolateral approaches (PL- or AL-CLASS), or minimal invasive posterolateral or anterolateral approaches (PL- or AL-MIS) were performed. CLASS incisions were 18 cm. To avoid postoperative bias, MIS incisions were extended at skin level to 18 cm at the end of the procedure. The HHS as well as patient-centered questionnaires (SF-36, WOMAC and OHS) was obtained preoperatively, at six weeks and one year after the index operation. Preoperative data, blood loss, hemoglobin, muscle damage parameters and radiological parameters were analyzed. In order to detect a minimal clinically important difference of five points or more between the MIS or CLASS groups with respect to the Harris Hip Score at the 0.05 alpha level with 80% power, 120 patients were enrolled in the study.

Results: Mean incision length of the THAs performed by MIS was 7.8 (SD = 1.6). In the patients of the MIS group a significant increased mean HHS was observed compared with the CLASS (p = 0.03) after six weeks and one year. This difference was caused by the favorable results of the PL-MIS (p = 0.009). Of the three patient-centered questionnaires, the SF-36 results were also favourable in the PL-MIS group after six weeks (p = 0.04). In the MIS group operation time was longer (p < 0.001) and a learning curve was observed based on operation time and complication rate. Peri-operative complications rates were not significantly different between the groups. Blood loss, hemoglobin, muscle damage parameters and radiological parameters also showed no difference.

Conclusions: This double-blind, randomized study reveals an improved clinical outcome of the PL-MIS compared with the AL-MIS, PL-CLASS and AL-CLASS after six weeks and one year follow-up with the Harris Hip Score as primary endpoint.

Introduction: Radial Impaction Grafting (RIG) has been proposed as a method for improving durability and reliability of cementing a collared femoral component in radial compressed bonegraft. In a prospective, baseline-control, multicenter clinical study the clinical and quality of life scores, survival rate, complications and radiographic findings were evaluated. The main objective of this study is to establish and indentify factors that contribute to the fracture rate. We tried to establish a model that represents the simplest combination of factors that predict femur fracture following the RIG technique.

Patients and Methods: Eighty-eight patients enrolled the study: 59 women and 29 men with average age of 74 (38–90) years. The average follow-up was 4 years (2–7.2). The results of 81 patients were evaluated. The Endo-classification (EC) was used for the determination of the pre-operative femoral bone loss; type 1 was noticed in 25 cases, type 2 in 44, type 3 in 17 and type 4 in 1 case.

At 70 patients the femur was augmented (mesh, cerclage(s) and/or plate). A short stem (115–135mm) was used in 48% and a long stem (165–225mm) in 52% of the cases.

Results: The average total HHS increased from a pre-operative score of 44 (median 44) to 91 (median 94) at > 5 years fu and the HHS-pain score from 17 (median 20) respectively to 43 (median 44). The average VAS for pain at > 5 years fu was 2.5 (0–100 scale). Ninety-three percent of the patients were very-extremely satisfied with the result.

Postoperative the femoral stem had a varus position (6 –10°) in 4 cases. In 6 cases the stem was in posterior and 3 cases in anterior position.

Progressive subsidence was demonstrated in 1 patient increasing to 5 mm at 1 year fu. Three patients showed subsidence of 3 mm at 3 months, but were stable afterwards. Slightly increasing radiolucent lines (> 2 mm) were noticed in 2 patients in subcortical areas, but never any signs of osteolysis.

Intra- and postoperative femoral fractures occurred in 12 patients (13,6%). There were 3 dislocations and 1 loosening of a trochanteric osteotomy. Despite the fractures there was no loosening of a stem during follow-up period.

After bivariate multilevel analysis, conducted to determine a relationship between the fracture complication and all other variables, a multivariate model was developed of the most significant variables to determine the predictor factors for femoral fracture. Only the Endo-classification and age are predictors for a fracture following a RIG procedure (p-value 0.003).

Each higher EC type increases the probability of a fracture after RIG 2.01 times and each added year of life 1.07 times. So the risk of getting a femoral fracture increases exponentially with age from 1.7% at 55 years to 15.5% at 90 years in EC type 1. The fracture risk in EC type 4 increases from 4.7% at 40 years to almost 60% at 90 years.

Background: The purpose of this systematic review was to determine the clinical and radiologic benefit of hydroxyapatite-coating in uncemented primary total hip arthroplasty.

Methods: A database of Medline articles published up to september 2007 was compiled and relevant references screened. Studies that satisfied the following selection criteria were included:

a proper randomized controlled trial;

Results: Eight studies, involving 857 patients, were included in the review. Observer agreement was 94%, while the interobserver reliability was K =.799 (.611 −.987); P < 0.001. Pooled analysis for Harris Hip Score as a clinical outcome measure demonstated no advantage of the hydroxyapatite coating (WMD: 1.49, CI: −2.32 to 5.31, P = 0.44). Radiologically, both groups showed equal presence of endosteal bone ingrowth (RR: 1.04, CI: 0.88 to 1.23, P = 0.66) and radio-active lines (RR: 1.02, CI: 0.90 to 1.16, P = 0.74) in the surface area of the prosthesis. Pooling on stem subsidence was not feasible, because three different measurement techniques were used.

Conclusion: Based on eight randomized controlled trials, this meta-analysis demonstrates no clinical nor radiological benefits to the application of a hydroxy-apatite coating on a femoral component in uncemented primary total hip arthroplasty.