Cartilage thickness in the hip joint measured by MRI and stereology – a methodological study

AbstractObjectiveThe purpose of this study was to develop a precise and efficient method for estimating the thickness of the articular cartilage in the hip joint and hence three different stereologic methods were tested based on Magnetic Resonance Imaging.DesignTwenty two females and four males with hip dysplasia underwent MRI. The thickness of the femoral and acetabular cartilage was estimated.ResultsThe results for all three methods showed that the observed total variance on cartilage thickness is small. The mean thickness of the acetabular cartilage measured by the three different methods ranged between 1.15mm and 1.46mm. The mean thickness for the femoral cartilage measured by the three different methods ranged between 1.18mm and 1.78mm. The measurements took 15–20min per hip to carry out.ConclusionMethods 1 and 3 are as precise but we favour method 3 because the measurements are done on images obtained through the center of the femoral head which means that the cartilage surface is intersected perpendicular and partial volume effect avoided. We suggest that this method can be advantageous for assessing the progression of osteoarthritis in dysplastic hips after periacetabular osteotomy

Effect of early supervised progressive resistance training compared to unsupervised home-based exercise after fast-track total hip replacement applied to patients with preoperative functional limitations. A single-blinded randomised controlled trial

SummaryObjectiveTo examine if 2 weekly sessions of supervised progressive resistance training (PRT) in combination with 5 weekly sessions of unsupervised home-based exercise is more effective than 7 weekly sessions of unsupervised home-based exercise in improving leg-extension power of the operated leg 10 weeks after total hip replacement (THR) in patients with lower pre-operative function.MethodA total of 73 patients scheduled for THR were randomised (1:1) to intervention group (IG, home based exercise 5 days/week and PRT 2 days/week) or control group (CG, home based exercise 7 days/week). The primary endpoint was change in leg extension power at 10 week follow up. Secondary outcomes were isometric hip muscle strength, sit-to-stand test, stair climb test, 20 m walking speed and patient-reported outcome (HOOS).ResultsSixty-two completed the trial (85%). Leg extension power increased from baseline to the 10 week follow up in both groups; mean [95% CI] IG: 0.29 [0.13; 0.45] and CG: 0.26 [0.10; 0.42] W/kg, with no between-group difference (primary outcome) (P = 0.79). Maximal walking speed (P = 0.008) and stair climb performance (P = 0.04) improved more in the IG compared to CG, no other between-group differences existed.ConclusionsIn this trial, supervised PRT twice a week in addition to 5 weekly sessions of unsupervised exercise for 10 weeks was not superior to 7 weekly sessions of unsupervised home-based exercise for 10 weeks in improving the primary outcome, leg-extension power of the operated leg, at the primary endpoint 10 weeks after surgery in THR patients with lower pre-operative function.Trial registration: NCT01214954

Low arthroplasty survival after treatment for proximal humerus fracture sequelae: 3,245 shoulder replacements from the Nordic Arthroplasty Register Association

Background and purpose - Proximal humerus fractures (PHF) may result in sequelae indicating arthroplasty. We report cumulative survival rates and reasons for revision after arthroplasty for proximal humerus fracture sequelae (PHFS). Patients and methods - Data were derived from the Nordic Arthroplasty Register Association. The Kaplan-Meier method was used to illustrate survival rates. A scaled Schoenfeld residual plot was used to report the risk of revision for men relative to women in patients who were treated with reverse shoulder arthroplasty (RSA). Revision was defined as removal or exchange of any component or the addition of a glenoid component. Results - 30,190 primary arthroplasties were reported from 2004 to 2016, of which 3,245 were for PHFS. The estimated 1-, 5-, and 10-year cumulative survival rates (95% CI) were 96% (95-97), 90% (89-92), and 86% (83-88) for stemmed hemiarthroplasty and 94% (92-95), 89% (87-91), and 86% (82-90) for RSA with a median time to revision of 18 months (IQR 9-44) and 3 months (IQR 0-17). The risk of revision for men relative to women in patients who were treated with RSA was 3.2 (1.9-5.1) 0-1 year after surgery and 1.9 (0.9-4.1) 1-8 years after surgery. The estimated 1-, 5-, and 10-year cumulative survival rates (95% CI) were 94% (92-96), 88% (85-90), and 80% (75-86) for men and 95% (94-96), 86% (84-89), and 81% (77-84) for young patients. Interpretation - Shoulder arthroplasty for PHFS was associated with lower survival rates, compared with previously published results of shoulder arthroplasty for acute PHF. The low arthroplasty survival rates for men and young patients especially are worrying