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
Pulsed electromagnetic field (PEMF) stimulation was evaluated after anterior cervical discectomy and fusion (ACDF) procedures in a randomized, controlled clinical study performed for United States Food and Drug Administration (FDA) approval. PEMF significantly increased fusion rates at six months, but 12-month fusion outcomes for subjects at elevated risk for pseudoarthrosis were not thoroughly reported. The objective of the current study was to evaluate the effect of PEMF treatment on subjects at increased risk for pseudoarthrosis after ACDF procedures. Two evaluations were performed that compared fusion rates between PEMF stimulation and a historical control (160 subjects) from the FDA investigational device exemption (IDE) study: a Objectives
Methods
Bone loss in the proximal tibia and distal femur
is frequently encountered in revision knee replacement surgery.
The various options for dealing with this depend on the extent of
any bone loss. We present our results with the use of cementless
metaphyseal metal sleeves in 103 patients (104 knees) with a mean
follow-up of 43 months (30 to 65). At final follow-up, sleeves in
102 knees had good osseointegration. Two tibial sleeves were revised
for loosening, possibly due to infection. The average pre-operative Oxford Knee Score was 23 (11 to 36)
and this improved to 32 (15 to 46) post-operatively. These early
results encourage us to continue with the technique and monitor
the outcomes in the long term. Cite this article:
The use of ilioischial cage reconstruction for
pelvic discontinuity has been replaced by the Trabecular Metal (Zimmer,
Warsaw, Indiana) cup-cage technique in our institution, due to the
unsatisfactory outcome of using a cage alone in this situation.
We report the outcome of 26 pelvic discontinuities in 24 patients
(20 women and four men, mean age 65 years (44 to 84)) treated by
the cup-cage technique at a mean follow-up of 82 months (12 to 113)
and compared them with a series of 19 pelvic discontinuities in
19 patients (18 women and one man, mean age 70 years (42 to 86))
treated with a cage at a mean follow-up of 69 months (1 to 170).
The clinical and radiological outcomes as well as the survivorship
of the groups were compared. In all, four of the cup-cage group
(15%) and 13 (68%) of the cage group failed due to septic or aseptic
loosening. The seven-year survivorship was 87.2% (95% confidence interval
(CI) 71 to 103) for the cup-cage group and 49.9% (95% CI 15 to 84)
for the cage-alone group (p = 0.009). There were four major complications
in the cup-cage group and nine in the cage group. Radiological union
of the discontinuity was found in all successful cases in the cup-cage
group and three of the successful cage cases. Three hips in the
cup-cage group developed early radiological migration of the components,
which stabilised with a successful outcome. Cup-cage reconstruction is a reliable technique for treating
pelvic discontinuity in mid-term follow-up and is preferred to ilioischial
cage reconstruction. If the continuity of the bone graft at the
discontinuity site is not disrupted, early migration of the components
does not necessarily result in failure. Cite this article:
We evaluated the accuracy with which a custom-made
acetabular component could be positioned at revision arthroplasty
of the hip in patients with a Paprosky type 3 acetabular defect. A total of 16 patients with a Paprosky type 3 defect underwent
revision surgery using a custom-made trabecular titanium implant.
There were four men and 12 women with a median age of 67 years (48
to 79). The planned inclination (INCL), anteversion (AV), rotation
and centre of rotation (COR) of the implant were compared with the post-operative
position using CT scans. A total of seven implants were malpositioned in one or more parameters:
one with respect to INCL, three with respect to AV, four with respect
to rotation and five with respect to the COR. To the best of our knowledge, this is the first study in which
CT data acquired for the pre-operative planning of a custom-made
revision acetabular implant have been compared with CT data on the
post-operative position. The results are encouraging. 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:
Trabecular metal (TM) augments are a relatively
new option for reconstructing segmental bone loss during acetabular
revision. We studied 34 failed hip replacements in 34 patients that
were revised between October 2003 and March 2010 using a TM acetabular
shell and one or two augments. The mean age of the patients at the
time of surgery was 69.3 years (46 to 86) and the mean follow-up
was 64.5 months (27 to 107). In all, 18 patients had a minor column
defect, 14 had a major column defect, and two were associated with
pelvic discontinuity. The hip centre of rotation was restored in
27 patients (79.4%). The Oxford hip score increased from a mean
of 15.4 points (6 to 25) before revision to a mean of 37.7 (29 to
47) at the final follow-up. There were three aseptic loosenings
of the construct, two of them in the patients with pelvic discontinuity.
One septic loosening also occurred in a patient who had previously
had an infected hip replacement. The augments remained stable in
two of the failed hips. Whenever there was a loose acetabular component
in contact with a stable augment, progressive metal debris shedding
was evident on the serial radiographs. Complications included another
deep infection treated without revision surgery. Good clinical and
radiological results can be expected for bone-deficient acetabula
treated by a TM cup and augment, but for pelvic discontinuities
this might not be a reliable option. Cite this article:
Reconstruction of the acetabulum after failed total hip arthroplasty
(THA) can be a surgical challenge in the presence of severe bone
loss. We report the long-term survival of a porous tantalum revision
acetabular component, its radiological appearance and quality of
life outcomes. We reviewed the results of 46 patients who had undergone revision
of a failed acetabular component with a Paprosky II or III bone
defect and reconstruction with a hemispherical, tantalum acetabular
component, supplementary screws and a cemented polyethylene liner.Aims
Patients and Methods
The management of bone loss in revision replacement of the knee remains a challenge despite an array of options available to the surgeon. Bone loss may occur as a result of the original disease, the design of the prosthesis, the mechanism of failure or technical error at initial surgery. The aim of revision surgery is to relieve pain and improve function while addressing the mechanism of failure in order to reconstruct a stable platform with transfer of load to the host bone. Methods of reconstruction include the use of cement, modular metal augmentation of prostheses, custom-made, tumour-type or hinged implants and bone grafting. The published results of the surgical techniques are summarised and a guide for the management of bone defects in revision surgery of the knee is presented.
Bone allografts can be used in any kind of surgery involving bone from minor defects to major bone loss after tumour resection. This review describes the various types of bone grafts and the current knowledge on bone allografts, from procurement and preparation to implantation. The surgical conditions for optimising the incorporation of bone are outlined, and surgeon expectations from a bone allograft discussed.
Vascularised fibular grafts (VFGs ) are a valuable
surgical technique in limb salvage after resection of a tumour.
The primary objective of this multicentre study was to assess the
risk factors for failure and complications for using a VFG after
resection of a tumour. The study involved 74 consecutive patients (45 men and 29 women
with mean age of 23 years (1 to 64) from four tertiary centres for
orthopaedic oncology who underwent reconstruction using a VFG after
resection of a tumour between 1996 and 2011. There were 52 primary
and 22 secondary reconstructions. The mean follow-up was 77 months
(10 to 195). In all, 69 patients (93%) had successful limb salvage; all of
these united and 65 (88%) showed hypertrophy of the graft. The mean
time to union differed between those involving the upper (28 weeks;
12 to 96) and lower limbs (44 weeks; 12 to 250). Fracture occurred
in 11 (15%), and nonunion in 14 (19%) patients. In 35 patients (47%) at least one complication arose, with a
greater proportion in lower limb reconstructions, non-bridging osteosynthesis,
and in children. These complications resulted in revision surgery
in 26 patients (35%). VFG is a successful and durable technique for reconstruction
of a defect in bone after resection of a tumour, but is accompanied
by a significant risk of complications, that often require revision
surgery. Union was not markedly influenced by the need for chemo-
or radiotherapy, but should not be expected during chemotherapy.
Therefore, restricted weight-bearing within this period is advocated. Cite this article:
Failure of total hip arthroplasty with acetabular deficiency occurred in 55 patients (60 hips) and was treated with acetabular revision using morsellised allograft and a cemented metal-backed component. A total of 50 patients (55 hips) were available for clinical and radiological evaluation at a mean follow-up of 5.8 years (3 to 9.5). No hip required further revision of the acetabular component because of aseptic loosening. All the hips except one had complete incorporation of the allograft demonstrated on the radiographs. A complete radiolucent line of >
1 mm was noted in two hips post-operatively. A good to excellent result occurred in 50 hips (91%). With radiological evidence of aseptic loosening of the acetabular component as the end-point, the survivorship at a mean of 5.8 years after surgery was 96.4%. The use of impacted allograft chips in combination with a cemented metal-backed acetabular component and screw fixation can achieve good medium-term results in patients with acetabular bone deficiency.
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:
The demand for spinal surgery and its costs have
both risen over the past decade. In 2008 the aggregate hospital
bill for surgical care of all spinal procedures was reported to
be $33.9 billion. One key driver of rising costs is spinal implants.
In 2011 our institution implemented a cost containment programme
for spinal implants which was designed to reduce the prices of individual
spinal implants and to reduce the inter-surgeon variation in implant costs.
Between February 2012 and January 2013, our spinal surgeons performed
1493 spinal procedures using implants from eight different vendors.
By applying market analysis and implant cost data from the previous
year, we established references prices for each individual type
of spinal implant, regardless of vendor, who were required to meet
these unit prices. We found that despite the complexity of spinal
surgery and the initial reluctance of vendors to reduce prices,
significant savings were made to the medical centre. Cite this article: 2015; 97-B:1102–5.
Revision arthroplasty after infection can often be complicated by both extensive bone loss and a relatively high rate of re-infection. Using allograft to address the bone loss in such patients is controversial because of the perceived risk of bacterial infection from the use of avascular graft material. We describe 12 two-stage revisions for infection in which segmental allografts were loaded with antibiotics using iontophoresis, a technique using an electrical potential to drive ionised antibiotics into cortical bone. Iontophoresis produced high levels of antibiotic in the allograft, which eluted into the surrounding tissues. We postulate that this offers protection from infection in the high-risk peri-operative period. None of the 12 patients who had two-stage revision with iontophoresed allografts had further infection after a mean period of 47 months (14 to 78).
Large osteochondral lesions (OCLs) of the shoulder
of the talus cannot always be treated by traditional osteochondral
autograft techniques because of their size, articular geometry and
loss of an articular buttress. We hypothesised that they could be
treated by transplantation of a vascularised corticoperiosteal graft
from the ipsilateral medial femoral condyle. Between 2004 and 2011, we carried out a prospective study of
a consecutive series of 14 patients (five women, nine men; mean
age 34.8 years, 20 to 54) who were treated for an OCL with a vascularised
bone graft. Clinical outcome was assessed using a visual analogue
scale (VAS) for pain and the American Orthopaedic Foot and Ankle Society
(AOFAS) hindfoot score. Radiological follow-up used plain radiographs
and CT scans to assess graft incorporation and joint deterioration. At a mean follow-up of 4.1 years (2 to 7), the mean VAS for pain
had decreased from 5.8 (5 to 8) to 1.8 (0 to 4) (p = 0.001) and
the mean AOFAS hindfoot score had increased from 65 (41 to 70) to
81 (54 to 92) (p = 0.003). Radiologically, the talar contour had
been successfully reconstructed with stable incorporation of the
vascularised corticoperiosteal graft in all patients. Joint degeneration
was only seen in one ankle. Treatment of a large OCL of the shoulder of the talus with a
vascularised corticoperiosteal graft taken from the medial condyle
of the femur was found to be a safe, reliable method of restoring
the contour of the talus in the early to mid-term. Cite this article:
We report the results of revision total knee
replacement (TKR) in 26 patients with major metaphyseal osteolytic defects
using 29 trabecular metal cones in conjunction with a rotating hinged
total knee prosthesis. The osteolytic defects were types II and
III (A or B) according to the Anderson Orthopaedic Research Institute
(AORI) classification. The mean age of the patients was 72 years
(62 to 84) and there were 15 men and 11 women. In this series patients had
undergone a mean of 2.34 previous total knee arthroplasties. The
main objective was to restore anatomy along with stability and function
of the knee joint to allow immediate full weight-bearing and active
knee movement. Outcomes were measured using Knee Society scores,
Oxford knee scores, range of movement of the knee and serial radiographs.
Patients were followed for a mean of 36 months (24 to 49). The mean
Oxford knee clinical scores improved from 12.83 (10 to 15) to 35.20
(32 to 38) (p <
0.001) and mean American Knee Society scores
improved from 33.24 (13 to 36) to 81.12 (78 to 86) (p <
0.001).
No radiolucent lines suggestive of loosening were seen around the trabecular
metal cones, and by one year all the radiographs showed good osteo-integration.
There was no evidence of any collapse or implant migration. Our
early results confirm the findings of others that trabecular metal
cones offer a useful way of managing severe bone loss in revision
TKR. Cite this article:
Cancellous allograft bone chips are commonly
used in the reconstruction of defects in bone after removal of benign tumours.
We investigated the MRI features of grafted bone chips and their
change over time, and compared them with those with recurrent tumour.
We retrospectively reviewed 66 post-operative MRIs from 34 patients
who had undergone curettage and grafting with cancellous bone chips
to fill the defect after excision of a tumour. All grafts showed
consistent features at least six months after grafting: homogeneous
intermediate or low signal intensities with or without scattered
hyperintense foci (speckled hyperintensities) on T1 images; high
signal intensities with scattered hypointense foci (speckled hypointensities)
on T2 images, and peripheral rim enhancement with or without central
heterogeneous enhancements on enhanced images. Incorporation of
the graft occurred from the periphery to the centre, and was completed
within three years. Recurrent lesions consistently showed the same signal
intensities as those of pre-operative MRIs of the primary lesions.
There were four misdiagnoses, three of which were chondroid tumours. We identified typical MRI features and clarified the incorporation
process of grafted cancellous allograft bone chips. The most important
characteristics of recurrent tumours were that they showed the same
signal intensities as the primary tumours. It might sometimes be
difficult to differentiate grafted cancellous allograft bone chips
from a recurrent chondroid tumour. Cite this article:
Acetabular bone loss is a challenging problem
facing the revision total hip replacement surgeon. Reconstruction
of the acetabulum depends on the presence of anterosuperior and
posteroinferior pelvic column support for component fixation and
stability. The Paprosky classification is most commonly used when
determining the location and degree of acetabular bone loss. Augments
serve the function of either providing primary construct stability
or supplementary fixation. When a pelvic discontinuity is encountered we advocate the use
of an acetabular distraction technique with a jumbo cup and modular
porous metal acetabular augments for the treatment of severe acetabular
bone loss and associated chronic pelvic discontinuity. Cite this article:
We used a canine intercalary bone defect model to determine the effects of recombinant human osteogenic protein 1 (rhOP-1) on allograft incorporation. The allograft was treated with an implant made up of rhOP-1 and type I collagen or with type I collagen alone. Radiographic analysis showed an increased volume of periosteal callus in both test groups compared with the control group at weeks 4, 6, 8 and 10. Mechanical testing after 12 weeks revealed increased maximal torque and stiffness in the rhOP-1 treated groups compared with the control group. These results indicate a benefit from the use of an rhOP-1 implant in the healing of bone allografts. The effect was independent of the position of the implant. There may be a beneficial clinical application for this treatment.