An uncemented hemispherical acetabular component
is the mainstay of acetabular revision and gives excellent long-term
results. Occasionally, the degree of acetabular bone loss means that a
hemispherical component will be unstable when sited in the correct
anatomical location or there is minimal bleeding host bone left
for biological fixation. On these occasions an alternative method
of reconstruction has to be used. A major column structural allograft has been shown to restore
the deficient bone stock to some degree, but it needs to be off-loaded
with a reconstruction cage to prevent collapse of the graft. The
use of porous metal augments is a promising method of overcoming
some of the problems associated with structural allograft. If the defect
is large, the augment needs to be protected by a cage to allow ingrowth
to occur. Cup-cage reconstruction is an effective method of treating
chronic pelvic discontinuity and large contained or uncontained
bone defects. This paper presents the indications, surgical techniques and
outcomes of various methods which use acetabular reconstruction
cages for revision total hip arthroplasty. Cite this article:
The purpose of this retrospective study was to evaluate the minimum
five-year outcome of revision total hip arthroplasty (THA) using
the Kerboull acetabular reinforcement device (KARD) in patients
with Paprosky type III acetabular defects and destruction of the
inferior margin of the acetabulum. We identified 36 patients (37 hips) who underwent revision THA
under these circumstances using the KARD, fresh frozen allograft
femoral heads, and reconstruction of the inferior margin of the
acetabulum. The Merle d’Aubigné system was used for clinical assessment.
Serial anteroposterior pelvic radiographs were used to assess migration
of the acetabular component.Aims
Patients and Methods
Revision knee arthroplasty presents a number
of challenges, not least of which is obtaining solid primary fixation
of implants into host bone. Three anatomical zones exist within
both femur and tibia which can be used to support revision implants.
These consist of the joint surface or epiphysis, the metaphysis
and the diaphysis. The methods by which fixation in each zone can
be obtained are discussed. The authors suggest that solid fixation
should be obtained in at least two of the three zones and emphasise
the importance of pre-operative planning and implant selection. Cite this article:
Increasing innovation in rapid prototyping (RP)
and additive manufacturing (AM), also known as 3D printing, is bringing
about major changes in translational surgical research. This review describes the current position in the use of additive
manufacturing in orthopaedic surgery. Cite this article:
In order to address acetabular defects, porous metal revision acetabular components and augments have been developed, which require fixation to each other. The fixation technique that results in the smallest relative movement between the components, as well as its influence on the primary stability with the host bone, have not previously been determined. A total of 18 composite hemipelvises with a Paprosky IIB defect were implanted using a porous titanium 56 mm multihole acetabular component and 1 cm augment. Each acetabular component and augment was affixed to the bone using two screws, while the method of fixation between the acetabular component and augment varied for the three groups of six hemipelvises: group S, screw fixation only; group SC, screw plus cement fixation; group C, cement fixation only. The implanted hemipelvises were cyclically loaded to three different loading maxima (0.5 kN, 0.9 kN, and 1.8 kN).Objectives
Methods
Few reconstructive techniques are available for patients requiring
complex acetabular revisions such as those involving Paprosky type
2C, 3A and 3B deficiencies and pelvic discontinuity. Our aim was
to describe the development of the patient specific Triflange acetabular
component for use in these patients, the surgical technique and
mid-term results. We include a description of the pre-operative
CT scanning, the construction of a model, operative planning, and
surgical technique. All implants were coated with porous plasma
spray and hydroxyapatite if desired. A multicentre, retrospective review of 95 complex acetabular
reconstructions in 94 patients was performed. A total of 61 (64.2%)
were female. The mean age of the patients was 66 (38 to 85). The
mean body mass index was 29 kg/m2 (18 to 51). Outcome
was reported using the Harris Hip Score (HHS), complications, failures
and survival.Aims
Patients and Methods
This paper describes the methodology, validation and reliability
of a new computer-assisted method which uses models of the patient’s
bones and the components to measure their migration and polyethylene
wear from radiographs after total hip arthroplasty (THA). Models of the patient’s acetabular and femoral component obtained
from the manufacturer and models of the patient’s pelvis and femur
built from a single computed tomography (CT) scan, are used by a
computer program to measure the migration of the components and
the penetration of the femoral head from anteroposterior and lateral radiographs
taken at follow-up visits. The program simulates the radiographic
setup and matches the position and orientation of the models to
outlines of the pelvis, the acetabular and femoral component, and
femur on radiographs. Changes in position and orientation reflect
the migration of the components and the penetration of the femoral
head. Validation was performed using radiographs of phantoms simulating
known migration and penetration, and the clinical feasibility of
measuring migration was assessed in two patients.Aims
Materials and Methods
The optimal method of tibial component fixation remains uncertain
in total knee arthroplasty (TKA). Hydroxyapatite coatings have been
applied to improve bone ingrowth in uncemented designs, but may
only coat the directly accessible surface. As peri-apatite (PA)
is solution deposited, this may increase the coverage of the implant
surface and thereby fixation. We assessed the tibial component fixation
of uncemented PA-coated TKAs Patients were randomised to PA-coated or cemented TKAs. In 60
patients (30 in each group), radiostereometric analysis of tibial
component migration was evaluated as the primary outcome at baseline,
three months post-operatively and at one, two and five years. A
linear mixed-effects model was used to analyse the repeated measurements.Aims
Patients and Methods
We evaluated clinical and radiographic outcomes of total shoulder
arthroplasty (TSA) using the second-generation Trabecular Metal
(TM) Glenoid component. The first generation component was withdrawn
in 2005 after a series of failures were reported. Between 2009 and
2012, 40 consecutive patients with unilateral TSA using the second-generation
component were enrolled in this clinical study. The mean age of
the patients was 63.8 years (40 to 75) and the mean follow-up was
38 months (24 to 42). Patients were evaluated using the Constant score (CS), the American
Shoulder and Elbow Surgeons (ASES) score and routine radiographs.Aims
Methods
We present a case series of ten metal-on-polyethylene total hip
arthroplasties (MoP THAs) with delayed dislocation associated with
unrecognised adverse local tissue reaction due to corrosion at the
trunnion and pseudotumour formation. The diagnosis was not suspected in nine of the ten patients (six
female/four male; mean age 66 years), despite treatment in a specialist
unit (mean time from index surgery to revision was 58 months, 36
to 84). It was identified at revision surgery and subsequently confirmed
by histological examination of resected tissue. Pre-operative assessment
and culture results ruled out infection. A variety of treatment
strategies were used, including resection of the pseudotumour and
efforts to avoid recurrent dislocation. Aims
Methods
A failed total ankle arthroplasty (TAA) is often associated with
much bone loss. As an alternative to arthrodesis, the surgeon may
consider a custom-made talar component to compensate for the bone
loss. Our aim in this study was to assess the functional and radiological
outcome after the use of such a component at mid- to long-term follow-up. A total of 12 patients (five women and seven men, mean age 53
years; 36 to77) with a failed TAA and a large talar defect underwent
a revision procedure using a custom-made talar component. The design
of the custom-made components was based on CT scans and standard
radiographs, when compared with the contralateral ankle. After the
anterior talocalcaneal joint was fused, the talar component was
introduced and fixed to the body of the calcaneum.Aims
Patients and Methods
This review summarises the technique of impaction
grafting with mesh augmentation for the treatment of uncontained
acetabular defects in revision hip arthroplasty. The ideal acetabular revision should restore bone stock, use
a small socket in the near-anatomic position, and provide durable
fixation. Impaction bone grafting, which has been in use for over
40 years, offers the ability to achieve these goals in uncontained
defects. The precepts of modern, revision impaction grafting are
that the segmental or cavitary defects must be supported with a
mesh; the contained cavity is filled with vigorously impacted morselised
fresh-frozen allograft; and finally, acrylic cement is used to stabilise
the graft and provide rigid, long-lasting fixation of the revised
acetabular component. Favourable results have been published with this technique. While
having its limitations, it is a viable option to address large acetabular
defects in revision arthroplasty. Cite this article:
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:
The last decade has seen a considerable increase
in the use of in total ankle arthroplasty (TAA) to treat patients
with end-stage arthritis of the ankle. However, the longevity of
the implants is still far from that of total knee and hip arthroplasties. The aim of this review is to outline a diagnostic and treatment
algorithm for the painful TAA to be used when considering revision
surgery. Cite this article:
Conventional cemented acetabular components are
reported to have a high rate of failure when implanted into previously
irradiated bone. We recommend the use of a cemented reconstruction
with the addition of an acetabular reinforcement cross to improve
fixation. We reviewed a cohort of 45 patients (49 hips) who had undergone
irradiation of the pelvis and a cemented total hip arthroplasty
(THA) with an acetabular reinforcement cross. All hips had received
a minimum dose of 30 Gray (Gy) to treat a primary nearby tumour
or metastasis. The median dose of radiation was 50 Gy (Q1 to Q3:
45 to 60; mean: 49.57, 32 to 72). The mean follow-up after THA was 51 months (17 to 137). The cumulative
probability of revision of the acetabular component for a mechanical
reason was 0% (0 to 0%) at 24 months, 2.9% (0.2 to 13.3%) at 60
months and 2.9% (0.2% to 13.3%) at 120 months, respectively. One
hip was revised for mechanical failure and three for infection. Cemented acetabular components with a reinforcement cross provide
good medium-term fixation after pelvic irradiation. These patients
are at a higher risk of developing infection of their THA. Cite this article:
We retrospectively reviewed 44 consecutive patients
(50 hips) who underwent acetabular re-revision after a failed previous
revision that had been performed using structural or morcellised
allograft bone, with a cage or ring for uncontained defects. Of
the 50 previous revisions, 41 cages and nine rings were used with
allografts for 14 minor-column and 36 major-column defects. We routinely
assessed the size of the acetabular bone defect at the time of revision
and re-revision surgery. This allowed us to assess whether host
bone stock was restored. We also assessed the outcome of re-revision
surgery in these circumstances by means of radiological characteristics,
rates of failure and modes of failure. We subsequently investigated
the factors that may affect the potential for the restoration of bone
stock and the durability of the re-revision reconstruction using
multivariate analysis. At the time of re-revision, there were ten host acetabula with
no significant defects, 14 with contained defects, nine with minor-column,
seven with major-column defects and ten with pelvic discontinuity.
When bone defects at re-revision were compared with those at the
previous revision, there was restoration of bone stock in 31 hips, deterioration
of bone stock in nine and remained unchanged in ten. This was a
significant improvement (p <
0.001). Morselised allografting
at the index revision was not associated with the restoration of
bone stock. In 17 hips (34%), re-revision was possible using a simple acetabular
component without allograft, augments, rings or cages. There were
47 patients with a mean follow-up of 70 months (6 to 146) available
for survival analysis. Within this group, the successful cases had
a minimum follow-up of two years after re-revision. There were 22 clinical
or radiological failures (46.7%), 18 of which were due to aseptic
loosening. The five and ten year Kaplan–Meier survival rate was
75% (95% CI, 60 to 86) and 56% (95% CI, 40 to 70) respectively with
aseptic loosening as the endpoint. The rate of aseptic loosening
was higher for hips with pelvic discontinuity (p = 0.049) and less
when the allograft had been in place for longer periods (p = 0.040). The use of a cage or ring over structural allograft bone for
massive uncontained defects in acetabular revision can restore host
bone stock and facilitate subsequent re-revision surgery to a certain
extent. Cite this article:
The custom triflange is a patient-specific implant
for the treatment of severe bone loss in revision total hip arthroplasty
(THA). Through a process of three-dimensional modelling and prototyping,
a hydroxyapatite-coated component is created for acetabular reconstruction.
There are seven level IV studies describing the clinical results
of triflange components. The most common complications include dislocation
and infection, although the rates of implant removal are low. Clinical
results are promising given the challenging problem. We describe
the design, manufacture and implantation process and review the
clinical results, contrasting them to other methods of acetabular
reconstruction in revision THA. Cite this article:
