Pathological assessment of periprosthetic tissues is important, not only for diagnosis, but also for understanding the pathobiology of implant failure. The host response to wear particle deposition in periprosthetic tissues is characterised by cell and tissue injury, and a reparative and inflammatory response in which there is an innate and adaptive immune response to the material components of implant wear. Physical and chemical characteristics of implant wear influence the nature of the response in periprosthetic tissues and account for the development of particular complications that lead to implant failure, such as osteolysis which leads to aseptic loosening, and soft-tissue necrosis/inflammation, which can result in pseudotumour formation. The innate response involves phagocytosis of implant-derived wear particles by macrophages; this is determined by pattern recognition receptors and results in expression of cytokines, chemokines and growth factors promoting inflammation and osteoclastogenesis; phagocytosed particles can also be cytotoxic and cause cell and tissue necrosis. The adaptive immune response to wear debris is characterised by the presence of lymphoid cells and most likely occurs as a result of a cell-mediated hypersensitivity reaction to cell and tissue components altered by interaction with the material components of particulate wear, particularly metal ions released from cobalt-chrome wear particles. Cite this article: Professor N. A. Athanasou. The pathobiology and pathology of aseptic implant failure.
Charcot neuro-osteoarthropathy (CN) of the midfoot
presents a major reconstructive challenge for the foot and ankle
surgeon. The Synthes 6 mm Midfoot Fusion Bolt is both designed and
recommended for patients who have a deformity of the medial column
of the foot due to CN. We present the results from the first nine
patients (ten feet) on which we attempted to perform fusion of the
medial column using this bolt. Six feet had concurrent hindfoot fusion
using a retrograde nail. Satisfactory correction of deformity of
the medial column was achieved in all patients. The mean correction
of calcaneal pitch was from 6°
(-15° to +18°) pre-operatively to 16° (7° to 23°) post-operatively;
the mean Meary angle from 26° (3° to 46°) to 1° (1° to 2°); and
the mean talometatarsal angle on dorsoplantar radiographs from 27°
(1° to 48°) to 1° (1° to 3°). However, in all but two feet, at least one joint failed to fuse.
The bolt migrated in six feet, all of which showed progressive radiographic
osteolysis, which was considered to indicate loosening. Four of
these feet have undergone a revision procedure, with good radiological
evidence of fusion. The medial column bolt provided satisfactory correction
of the deformity but failed to provide adequate fixation for fusion
in CN deformities in the foot. In its present form, we cannot recommend the routine use of this
bolt. Cite this article:
In the initial development of total shoulder arthroplasty (TSA),
the humeral component was usually fixed with cement. Cementless
components were subsequently introduced. The aim of this study was
to compare the long-term outcome of cemented and cementless humeral
components in arthroplasty of the shoulder. All patients who underwent primary arthroplasty of the shoulder
at our institution between 1970 and 2012 were included in the study.
There were 4636 patients with 1167 cemented humeral components and
3469 cementless components. Patients with the two types of fixation
were matched for nine different covariates using a propensity score
analysis. A total of 551 well-balanced pairs of patients with cemented
and cementless components were available after matching for comparison
of the outcomes. The clinical outcomes which were analysed included loosening
of the humeral component determined at revision surgery, periprosthetic
fractures, post-operative infection and operating time.Aims
Patients and Methods
The aims of this study were to report functional
outcomes of salvage procedures for patients with cerebral palsy (CP)
who have chronic dislocation of the hip using validated scoring
systems, and to compare the results of three surgical techniques. We reviewed 37 patients retrospectively. The mean age at the
time of surgery was 12.2 years (8 to 22) and the mean follow-up
was 56 months (24 to 114). Patients were divided into three groups:
14 who underwent proximal femoral resection arthroplasty (PFRA group
1), ten who underwent subtrochanteric valgus osteotomy (SVO group 2),
and 13 who underwent subtrochanteric valgus osteotomy with resection
of the femoral head (SVO with FHR group 3). All patients were evaluated
using the Caregiver Priorities and Child Health Index of Life with
Disabilities (CPCHILD) and the Pediatric Quality of Life Inventory
(PedsQL). Significant improvements occurred in most CPCHILD and PedsQL
subsection scores following surgery in all patients, without significant
differences between the groups. There were 12 post-operative complications.
Less severe complications were seen in group 1 than in groups 2
and 3. Salvage surgery appears to provide pain relief in patients with
CP who have painful chronic dislocation of the hip. The three salvage
procedures produced similar results, however, we recommend the use
of PFRA as the complications are less severe. Take home message: Salvage surgery can be of benefit to patients
with CP with chronic painful hip dislocation, but should be limited
to selected patients considering complications. Cite this article:
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
The Advance Medial-Pivot total knee arthroplasty (TKA) was designed
to reflect contemporary data regarding the kinematics of the knee.
We wished to examine the long-term results obtained with this prosthesis
by extending a previous evaluation. We retrospectively evaluated prospectively collected data from
225 consecutive patients (41 men and 184 women; mean age at surgery
71 years, 52 to 84) who underwent 284 TKAs with a mean follow-up
of 13.4 years (11 to 15). Implant failure, complication rate, clinical (both
subjective and objective) and radiological outcome were assessed.
Pre- and post-operative clinical and radiographic data were available
at regular intervals for all patients. A total of ten patients (4.4%;
ten TKAs) were lost to follow-up.Aims
Patients and Methods
The objective of this five-year prospective, blinded, randomised
controlled trial (RCT) was to compare femoral head penetration into
a vitamin E diffused highly cross-linked polyethylene (HXLPE) liner
with penetration into a medium cross-linked polyethylene control
liner using radiostereometric analysis. Patients scheduled for total hip arthroplasty (THA) were randomised
to receive either the study E1 (32 patients) or the control ArComXL
polyethylene (35 patients). The median age (range) of the overall
cohort was 66 years (40 to 76).Aims
Patients and Methods
Cement augmentation of pedicle screws could be used to improve screw stability, especially in osteoporotic vertebrae. However, little is known concerning the influence of different screw types and amount of cement applied. Therefore, the aim of this biomechanical A total of 54 osteoporotic human cadaver thoracic and lumbar vertebrae were instrumented with pedicle screws (uncemented, solid cemented or fenestrated cemented) and augmented with high-viscosity PMMA cement (0 mL, 1 mL or 3 mL). The insertion torque and bone mineral density were determined. Radiographs and CT scans were undertaken to evaluate cement distribution and cement leakage. Pull-out testing was performed with a material testing machine to measure failure load and stiffness. The paired Objectives
Materials and Methods
Injuries to the foot in athletes are often subtle
and can lead to a substantial loss of function if not diagnosed
and treated appropriately. For these injuries in general, even after
a diagnosis is made, treatment options are controversial and become
even more so in high level athletes where limiting the time away
from training and competition is a significant consideration. In this review, we cover some of the common and important sporting
injuries affecting the foot including updates on their management
and outcomes. Cite this article:
The Intraosseous Transcutaneous Amputation Prosthesis (ITAP)
may improve quality of life for amputees by avoiding soft-tissue
complications associated with socket prostheses and by improving
sensory feedback and function. It relies on the formation of a seal
between the soft tissues and the implant and currently has a flange
with drilled holes to promote dermal attachment. Despite this, infection
remains a significant risk. This study explored alternative strategies
to enhance soft-tissue integration. The effect of ITAP pins with a fully porous titanium alloy flange
with interconnected pores on soft-tissue integration was investigated.
The flanges were coated with fibronectin-functionalised hydroxyapatite
and silver coatings, which have been shown to have an antibacterial
effect, while also promoting viable fibroblast growth Aims
Materials and Methods
We present the results of 62 consecutive acetabular
revisions using impaction bone grafting and a cemented polyethylene
acetabular component in 58 patients (13 men and 45 women) after
a mean follow-up of 27 years (25 to 30). All patients were prospectively
followed. The mean age at revision was 59.2 years (23 to 82). We performed Kaplan–Meier (KM) analysis and also a Competing
Risk (CR) analysis because with long-term follow-up, the presence
of a competing event (i.e. death) prevents the occurrence of the
endpoint of re-revision. A total of 48 patients (52 hips) had died or had been re-revised
at final review in March 2011. None of the deaths were related to
the surgery. The mean Harris hip score of the ten surviving hips
in ten patients was 76 points (45 to 99). The KM survivorship at 25 years for the endpoint ‘re-revision
for any reason’ was 58.0% (95% confidence interval (CI) 38 to 73)
and for ‘re-revision for aseptic loosening’ 72.1% (95% CI 51 to
85). With the CR analysis we calculated the KM analysis overestimates
the failure rate with respectively 74% and 93% for these endpoints.
The current study shows that acetabular impaction bone grafting
revisions provide good clinical results at over 25 years. Cite this article:
The present study describes a novel technique for revitalising allogenic intrasynovial tendons by combining cell-based therapy and mechanical stimulation in an Specifically, canine flexor digitorum profundus tendons were used for this study and were divided into the following groups: (1) untreated, unprocessed normal tendon; (2) decellularised tendon; (3) bone marrow stromal cell (BMSC)-seeded tendon; and (4) BMSC-seeded and cyclically stretched tendon. Lateral slits were introduced on the tendon to facilitate cell seeding. Tendons from all four study groups were distracted by a servohydraulic testing machine. Tensile force and displacement data were continuously recorded at a sample rate of 20 Hz until 200 Newton of force was reached. Before testing, the cross-sectional dimensions of each tendon were measured with a digital caliper. Young’s modulus was calculated from the slope of the linear region of the stress-strain curve. The BMSCs were labeled for histological and cell viability evaluation on the decellularized tendon scaffold under a confocal microscope. Gene expression levels of selected extracellular matrix tendon growth factor genes were measured. Results were reported as mean ± SD and data was analyzed with one-way ANOVAs followed by Tukey’s post hoc multiple-comparison test.Objectives
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
Due to the complex anatomy of the pelvis, limb-sparing resections
of pelvic tumours achieving adequate surgical margins, can often
be difficult. The advent of computer navigation has improved the
precision of resection of these lesions, though there is little
evidence comparing resection with or without the assistance of navigation. Our aim was to evaluate the efficacy of navigation-assisted surgery
for the resection of pelvic bone tumours involving the posterior
ilium and sacrum. Using our prospectively updated institutional database, we conducted
a retrospective case control study of 21 patients who underwent
resection of the posterior ilium and sacrum, for the treatment of
a primary sarcoma of bone, between 1987 and 2015. The resection
was performed with the assistance of navigation in nine patients
and without navigation in 12. We assessed the accuracy of navigation-assisted
surgery, as defined by the surgical margin and how this affects
the rate of local recurrence, the disease-free survival and the
effects on peri-and post-operative morbidity. Aims
Patients and Methods
The purpose of this study was to evaluate the
natural history of rheumatoid disease of the shoulder over an eight-year
period. Our hypothesis was that progression of the disease is associated
with a decrease in function with time. A total of 22 patients (44 shoulders; 17 women, 5 men, (mean
age 63)) with rheumatoid arthritis were followed for eight years.
All shoulders were assessed using the Constant score, anteroposterior
radiographs (Larsen score, Upward-Migration-Index (UMI)) and ultrasound
(US). At final follow-up, the Short Form-36, disabilities of the
arm, shoulder and hand (DASH) Score, erythrocyte sedimentation rate
and use of anti-rheumatic medication were determined. The mean Constant score was 72 points (50 to 88) at baseline
and 69 points (25 to 100) at final follow-up. Radiological evaluation
showed progressive destruction of the peri-articular structures
with time. This progression of joint and rotator cuff destruction
was significantly associated with the Constant score. However, at
baseline only the extent of rotator cuff disease and the UMI could
predict the Constant score at final follow-up. A plain anteroposterior radiograph of the shoulder is sufficient
to assess any progression of rheumatoid disease and to predict functional
outcome in the long term by using the UMI as an indicator of rotator
cuff degeneration. Cite this article:
To investigate the longevity of uncemented fixation of a femoral
component in total hip arthroplasty (THA) in patients with Dorr
type C proximal femoral morphology. A total of 350 consecutive uncemented THA in 320 patients were
performed between 1983 and 1987, by a single surgeon using the Taperloc
femoral component. The 63 patients (68 hips) with Dorr type C proximal
femoral morphology were the focus of this review. The mean age of
the patients was 69 years (24 to 88) and mean follow-up was 16.6
years (ten to 29). Survival analysis included eight patients (eight
hips) who died without undergoing revision surgery prior to obtaining
ten years follow-up. All 55 surviving patients (60 hips) were available
for clinical assessment and radiographic review. As a comparator
group, the survival and implant fixation in the remaining 282 THAs
(257 patients) with Dorr type A and B morphology were evaluated.
The mean age of these patients was 52 years (20 to 82).Aims
Patients and Methods
We report on the outcome of the Synergy cementless femoral stem
with a minimum follow-up of 15 years (15 to 17). A retrospective review was undertaken of a consecutive series
of 112 routine primary cementless total hip arthroplasties (THAs)
in 102 patients (112 hips). There were 60 female and 42 male patients
with a mean age of 61 years (18 to 82) at the time of surgery. A
total of 78 hips in the 69 patients remain Aims
Patients and Methods
The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method. In this matched case study, 16 adult patients underwent 19 tibial lengthening over nails (LON) procedures. For the matched case group, 17 patients who underwent 19 Ilizarov tibial lengthenings were retrospectively matched to the LON group.Objectives
Methods
