This review examines the future of total hip arthroplasty, aiming to avoid past mistakes
The routine use of patient reported outcome measures
(PROMs) in evaluating the outcome after arthroplasty by healthcare
organisations reflects a growing recognition of the importance of
patients’ perspectives in improving treatment. Although widely embraced
in the NHS, there are concerns that PROMs are being used beyond
their means due to a poor understanding of their limitations. This paper reviews some of the current challenges in using PROMs
to evaluate total knee arthroplasty. It highlights alternative methods
that have been used to improve the assessment of outcome. Cite this article:
The August 2013 Trauma Roundup360 looks at: reverse oblique fractures do better with a cephalomedullary device; locking screws confer no advantage in tibial plateau fractures; it’s all about the radius of curvature; radius of curvature revisited; radial head replacement in complex elbow reconstruction; stem cells in early fracture haematoma; heterotrophic ossification in forearms; and Boston in perspective.
Previous studies of failure mechanisms leading
to revision total knee replacement (TKR) performed between 1986 and
2000 determined that many failed early, with a disproportionate
amount accounted for by infection and implant-associated factors
including wear, loosening and instability. Since then, efforts have
been made to improve implant performance and instruct surgeons in
best practice. Recently our centre participated in a multi-centre evaluation
of 844 revision TKRs from 2010 to 2011. The purpose was to report
a detailed analysis of failure mechanisms over time and to see if
failure modes have changed over the past 10 to 15 years. Aseptic
loosening was the predominant mechanism of failure (31.2%), followed
by instability (18.7%), infection (16.2%), polyethylene wear (10.0%),
arthrofibrosis (6.9%) and malalignment (6.6%). The mean time to
failure was 5.9 years (ten days to 31 years), 35.3% of all revisions
occurred at less than two years, and 60.2% in the first five years.
With improvements in implant and polyethylene manufacture, polyethylene
wear is no longer a leading cause of failure. Early mechanisms of
failure are primarily technical errors. In addition to improving
implant longevity, industry and surgeons must work together to decrease
these technical errors. All reports on failure of TKR contain patients
with unexplained pain who not infrequently have unmet expectations.
Surgeons must work to achieve realistic patient expectations pre-operatively,
and therefore, improve patient satisfaction post-operatively. Cite this article:
We live in troubled times. Increased opposition reliance on explosive devices, the widespread use of individual and vehicular body armour, and the improved survival of combat casualties have created many complex musculoskeletal injuries in the wars in Iraq and Afghanistan. Explosive mechanisms of injury account for 75% of all musculoskeletal combat casualties. Throughout all the echelons of care medical staff practice consistent treatment strategies of damage control orthopaedics including tourniquets, antibiotics, external fixation, selective amputations and vacuum-assisted closure. Complications, particularly infection and heterotopic ossification, remain frequent, and re-operations are common. Meanwhile, non-combat musculoskeletal casualties are three times more frequent than those derived from combat and account for nearly 50% of all musculoskeletal casualties requiring evacuation from the combat zone.
The June 2013 Research Roundup360 looks at: a contact patch to rim distance and metal ions; the matrix of hypoxic cartilage; CT assessment of early fracture healing; Hawthornes and radiographs; cardiovascular mortality and fragility fractures; and muscle strength decline preceding OA changes.
There are significant differences in the methods and styles of orthopaedic surgical training between continents, all with the aim to produce competent consultant surgeons, but the differences in training content and pathway are vast. We review and contrast the key differences between three continents.
Cartilage defects of the hip cause significant
pain and may lead to arthritic changes that necessitate hip replacement.
We propose the use of fresh osteochondral allografts as an option
for the treatment of such defects in young patients. Here we present
the results of fresh osteochondral allografts for cartilage defects
in 17 patients in a prospective study. The underlying diagnoses
for the cartilage defects were osteochondritis dissecans in eight
and avascular necrosis in six. Two had Legg-Calve-Perthes and one
a femoral head fracture. Pre-operatively, an MRI was used to determine
the size of the cartilage defect and the femoral head diameter.
All patients underwent surgical hip dislocation with a trochanteric
slide osteotomy for placement of the allograft. The mean age at
surgery was 25.9 years (17 to 44) and mean follow-up was 41.6 months
(3 to 74). The mean Harris hip score was significantly better after
surgery (p <
0.01) and 13 patients had fair to good outcomes.
One patient required a repeat allograft, one patient underwent hip
replacement and two patients are awaiting hip replacement. Fresh
osteochondral allograft is a reasonable treatment option for hip
cartilage defects in young patients. Cite this article:
The October 2014 Hip &
Pelvis Roundup360 looks at: functional acetabular orientation; predicting re-admission following THR; metal ions and resurfacing; lipped liners increase stability; all anaesthetics equal in hip fracture surgery; revision hip surgery in very young patients; and uncemented hips.
The mechanical performance of the cement-in-cement interface in revision surgery has not been fully investigated. The quantitative effect posed by interstitial fluids and roughening of the primary mantle remains unclear. We have analysed the strength of the bilaminar cement-bone interface after exposure of the surface of the primary mantle to roughening and fluid interference. The end surfaces of cylindrical blocks of cement were machined smooth (Ra = 200 nm) or rough (Ra = 5 μm) and exposed to either different volumes of water and carboxymethylcellulose (a bone-marrow equivalent) or left dry. Secondary blocks were cast against the modelled surface. Monoblocks of cement were used as a control group. The porosity of the samples was investigated using micro-CT. Samples were exposed to a single shearing force to failure. The mean failure load of the monoblock control was 5.63 kN (95% confidence interval (CI) 5.17 to 6.08) with an estimated shear strength of 36 MPa. When small volumes of any fluid or large volumes were used, the respective values fell between 4.66 kN and 4.84 kN with no significant difference irrespective of roughening (p >
0.05). Large volumes of carboxymethylcellulose significantly weakened the interface. Roughening in this group significantly increased the strength with failure loads of 2.80 kN (95% CI 2.37 to 3.21) compared with 0.86 kN (95% CI 0.43 to 1.27) in the smooth variant. Roughening of the primary mantle may not therefore be as crucial as has been previously thought in clinically relevant circumstances.
The aim of this study was to evaluate the functional
and oncological outcome of extracorporeally irradiated autografts
used to reconstruct the pelvis after a P1/2 internal hemipelvectomy. The study included 18 patients with a primary malignant bone
tumour of the pelvis. There were 13 males and five females with
a mean age of 24.8 years (8 to 62). Of these, seven had an osteogenic
sarcoma, six a Ewing’s sarcoma, and five a chondrosarcoma. At a
mean follow-up of 51.6 months (4 to 185), nine patients had died
with metastatic disease while nine were free from disease. Local
recurrence occurred in three patients all of whom eventually died of
their disease. Deep infection occurred in three patients and required
removal of their graft in two while the third underwent a hindquarter
amputation for extensive flap necrosis. The mean Musculoskeletal Tumor Society functional score of the
16 patients who could be followed-up for at least 12 months was
77% (50 to 90). Those 15 patients who completed the Toronto Extremity
Salvage Score questionnaire had a mean score of 71% (53 to 85). Extracorporeal irradiation and re-implantation of bone is a valid
method of reconstruction after an internal hemipelvectomy. It has
an acceptable morbidity and a functional outcome that compares favourably
with other available reconstructive techniques. Cite this article:
The aim of this experimental study on New Zealand’s white rabbits
was to investigate the transplantation of autogenous growth plate
cells in order to treat the injured growth plate. They were assessed
in terms of measurements of radiological tibial varus and histological
characteristics. An experimental model of plate growth medial partial resection
of the tibia in 14 New Zealand white rabbits was created. During
this surgical procedure the plate growth cells were collected and
cultured. While the second surgery was being performed, the autologous
cultured growth plate cells were grafted at the right tibia, whereas
the left tibia was used as a control group. Objectives
Methods
Resection of a primary sarcoma of the diaphysis
of a long bone creates a large defect. The biological options for reconstruction
include the use of a vascularised and non-vascularised fibular autograft. The purpose of the present study was to compare these methods
of reconstruction. Between 1985 and 2007, 53 patients (26 male and 27 female) underwent
biological reconstruction of a diaphyseal defect after resection
of a primary sarcoma. Their mean age was 20.7 years (3.6 to 62.4).
Of these, 26 (49 %) had a vascularised and 27 (51 %) a non-vascularised
fibular autograft. Either method could have been used for any patient in
the study. The mean follow-up was 52 months (12 to 259). Oncological,
surgical and functional outcome were evaluated. Kaplan–Meier analysis
was performed for graft survival with major complication as the
end point. At final follow-up, eight patients had died of disease. Primary
union was achieved in 40 patients (75%); 22 (42%) with a vascularised
fibular autograft and 18 (34%) a non-vascularised (p = 0.167). A
total of 32 patients (60%) required revision surgery. Kaplan–Meier
analysis revealed a mean survival without complication of 36 months
(0.06 to 107.3, Both groups seem to be reliable biological methods of reconstructing
a diaphyseal bone defect. Vascularised autografts require more revisions
mainly due to problems with wound healing in distal sites of tumour,
such as the foot. Cite this article:
The aim of this study was to examine whether asymmetric loading
influences macrophage elastase (MMP12) expression in different parts
of a rat tail intervertebral disc and growth plate and if MMP12
expression is correlated with the severity of the deformity. A wedge deformity between the ninth and tenth tail vertebrae
was produced with an Ilizarov-type mini external fixator in 45 female
Wistar rats, matched for their age and weight. Three groups were
created according to the degree of deformity (10°, 30° and 50°).
A total of 30 discs and vertebrae were evaluated immunohistochemically
for immunolocalisation of MMP12 expression, and 15 discs were analysed
by western blot and zymography in order to detect pro- and active
MMP12.Objectives
Methods
The objective of this study was to compare the elution characteristics,
antimicrobial activity and mechanical properties of antibiotic-loaded
bone cement (ALBC) loaded with powdered antibiotic, powdered antibiotic
with inert filler (xylitol), or liquid antibiotic, particularly focusing
on vancomycin and amphotericin B. Cement specimens loaded with 2 g of vancomycin or amphotericin
B powder (powder group), 2 g of antibiotic powder and 2 g of xylitol
(xylitol group) or 12 ml of antibiotic solution containing 2 g of
antibiotic (liquid group) were tested.Objectives
Methods
Neurogenic heterotopic ossification (NHO) is
a disorder of aberrant bone formation affecting one in five patients sustaining
a spinal cord injury or traumatic brain injury. Ectopic bone forms
around joints in characteristic patterns, causing pain and limiting
movement especially around the hip and elbow. Clinical sequelae
of neurogenic heterotopic ossification include urinary tract infection,
pressure injuries, pneumonia and poor hygiene, making early diagnosis
and treatment clinically compelling. However, diagnosis remains
difficult with more investigation needed. Our pathophysiological
understanding stems from mechanisms of basic bone formation enhanced
by evidence of systemic influences from circulating humor factors
and perhaps neurological ones. This increasing understanding guides
our implementation of current prophylaxis and treatment including
the use of non-steroidal anti-inflammatory drugs, bisphosphonates,
radiation therapy and surgery and, importantly, should direct future, more
effective ones.
Excessive mechanical stress on synovial joints causes osteoarthritis
(OA) and results in the production of prostaglandin E2 (PGE2), a
key molecule in arthritis, by synovial fibroblasts. However, the
relationship between arthritis-related molecules and mechanical
stress is still unclear. The purpose of this study was to examine
the synovial fibroblast response to cyclic mechanical stress using
an Human synovial fibroblasts were cultured on collagen scaffolds
to produce three-dimensional constructs. A cyclic compressive loading
of 40 kPa at 0.5 Hz was applied to the constructs, with or without
the administration of a cyclooxygenase-2 (COX-2) selective inhibitor
or dexamethasone, and then the concentrations of PGE2, interleukin-1β (IL-1β),
tumour necrosis factor-α (TNF-α), IL-6, IL-8 and COX-2 were measured.Objective
Method
Noise generation has been reported with ceramic-on-ceramic
articulations in total hip replacement (THR). This study evaluated
208 consecutive Delta Motion THRs at a mean follow-up of 21 months
(12 to 35). There were 141 women and 67 men with a mean age of 59
years (22 to 84). Patients were reviewed clinically and radiologically,
and the incidence of noise was determined using a newly described
assessment method. Noise production was examined against range of
movement, ligamentous laxity, patient-reported outcome scores, activity
level and orientation of the acetabular component. There were 143
silent hips (69%), 22 (11%) with noises other than squeaking, 17
(8%) with unreproducible squeaking and 26 (13%) with reproducible
squeaking. Hips with reproducible squeaking had a greater mean range
of movement (p <
0.001) and mean ligament laxity (p = 0.004), smaller
median head size (p = 0.01) and decreased mean acetabular component
inclination (p = 0.02) and anteversion angle (p = 0.02) compared
with the other groups. There was no relationship between squeaking
and age (p = 0.13), height (p = 0.263), weight (p = 0.333), body
mass index (p = 0.643), gender (p = 0.07) or patient outcome score
(p = 0.422). There were no revisions during follow-up. Despite the
surprisingly high incidence of squeaking, all patients remain satisfied
with their hip replacement. Cite this article:
The National Institute for Health and Clinical
Excellence (NICE) has thus far relied on historical data and predominantly
industry-sponsored trials to provide evidence for venous thromboembolic
(VTE) prophylaxis in joint replacement patients. We argue that the
NICE guidelines may be reliant on assumptions that are in need of
revision. Following the publication of large scale, independent
observational studies showing little difference between low-molecular-weight
heparins and aspirin, and recent changes to the guidance provided
by other international bodies, should NICE reconsider their recommendations? Cite this article:
