The aims of this study were to examine the rate at which the
positioning of the acetabular component, leg length discrepancy
and femoral offset are outside an acceptable range in total hip
arthroplasties (THAs) which either do or do not involve the use
of intra-operative digital imaging. A retrospective case-control study was undertaken with 50 patients
before and 50 patients after the integration of an intra-operative
digital imaging system in THA. The demographics of the two groups
were comparable for body mass index, age, laterality and the indication
for surgery. The digital imaging group had more men than the group without.
Surgical data and radiographic parameters, including the inclination
and anteversion of the acetabular component, leg length discrepancy,
and the difference in femoral offset compared with the contralateral
hip were collected and compared, as well as the incidence of altering
the position of a component based on the intra-operative image.Aims
Patients and Methods
A pelvic discontinuity occurs when the superior
and inferior parts of the hemi-pelvis are no longer connected, which
is difficult to manage when associated with a failed total hip replacement.
Chronic pelvic discontinuity is found in 0.9% to 2.1% of hip revision
cases with risk factors including severe pelvic bone loss, female
gender, prior pelvic radiation and rheumatoid arthritis. Common
treatment options include: pelvic plating with allograft, cage reconstruction,
custom triflange implants, and porous tantalum implants with modular augments.
The optimal technique is dependent upon the degree of the discontinuity,
the amount of available bone stock and the likelihood of achieving
stable healing between the two segments. A method of treating pelvic
discontinuity using porous tantalum components with a distraction
technique that achieves both initial stability and subsequent long-term
biological fixation is described. Cite this article:
We performed a retrospective examination of the
anteroposterior pelvic CT scout views of 419 randomly selected patients between
April 2004 and August 2009 in order to determine the prevalence
of cam-type femoroacetabular deformity in the asymptomatic population.
The CT scans had all been undertaken for conditions unrelated to
disorders of the hip. The frequency of cam-type femoroacetabular
deformity was assessed by measuring the α-angle of each hip on the
anteroposterior images. The α-angles were classified according to
the Copenhagen Osteoarthritis Study. Among 215 male hips (108 patients)
the mean α-angle was 59.12° (37.75° to 103.50°). Of these, a total
of 30 hips (13.95%) were defined as pathological, 32 (14.88%) as
borderline and 153 (71.16%) as normal. Among 540 female hips (272
patients) the mean α-angle was 45.47° (34.75° to 87.00°), with 30
hips (5.56%) defined as pathological, 33 (6.11%) as borderline and
477 (88.33%) as normal. It appears that the cam-type femoroacetabular
deformity is not rare among the asymptomatic population. These anatomical
abnormalities, as determined by an increased α-angle, appear to
be twice as frequent in men as in women. Although an association
between osteoarthritis and femoroacetabular impingement is believed
to exist, a long-term epidemiological study is needed to determine
the natural history of these anatomical abnormalities.
