Cement thickness of at least 2 mm is generally associated with more favorable results for the femoral component in cemented hip arthroplasty. However, French-designed stems have shown favorable outcomes even with thin cement mantle. The biomechanical behaviors of a French stem, Charnley-Marcel-Kerboull (CMK) and cement were researched in this study. Six polished CMK stems were implanted into a composite femur, and one million times dynamic loading tests were performed. Stem subsidence and the compressive force at the bone-cement interface were measured. Tantalum ball (ball) migration in the cement was analyzed by micro CTObjective
Methods
Favourable results for collarless polished tapered stems have been reported, and cement creep due to taper slip may be a contributing factor. However, the ideal cement thickness around polished stems remains unknown. We investigated the influence of cement thickness on stem subsidence and cement creep. We cemented six collarless polished tapered (CPT) stems (two stems each of small, medium and large sizes) into composite femurs that had been reamed with a large CPT rasp to achieve various thicknesses of the cement mantle. Two or three tantalum balls were implanted in the proximal cement in each femur. A cyclic loading test was then performed for each stem. The migration of the balls was measured three-dimensionally, using a micro-computed tomography (CT) scanner, before and after loading. A digital displacement gauge was positioned at the stem shoulder, and stem subsidence was measured continuously by the gauge. Final stem subsidence was measured at the balls at the end of each stem.Objectives
Methods
The purpose of this study was to determine patient-reported
outcomes of patients with mild to moderate developmental dysplasia
of the hip (DDH) and femoroacetabular impingement (FAI) undergoing
arthroscopy of the hip in the treatment of chondrolabral pathology.
A total of 28 patients with a centre-edge angle between 15° and
19° were identified from an institutional database. Their mean age
was 34 years (18 to 53), with 12 female and 16 male patients. All
underwent labral treatment and concomitant correction of FAI. There
were nine reoperations, with two patients requiring revision arthroscopy,
two requiring periacetabular osteotomy and five needing total hip arthroplasty. Patients who required further major surgery were more likely
to be older, male, and to have more severe DDH with a larger alpha
angle and decreased joint space. At a mean follow-up of 42 months (24 to 89), the mean modified
Harris hip score improved from 59 (20 to 98) to 82 (45 to 100; p
<
0.001). The mean Western Ontario and McMaster Universities
Osteoarthritis Index score improved from 30 (1 to 61) to 16 (0 to
43; p <
0.001). Median patient satisfaction was 9.0/10 (1 to
10). Patients reported excellent improvement in function following
arthroscopy of the hip. This study shows that with proper patient selection, arthroscopy
of the hip can be successful in the young patient with mild to moderate
DDH and FAI. Cite this article:
