The variation in surgical performance, both between
centres and individual surgeons, has recently been of significant
political, media and public interest. Within the United Kingdom, a
government agenda to increase accountability amongst surgeons has
led to the online publication of ‘surgeon-level’ data. Surgeons,
journalists and the public need to understand these data if they
are to be useful in driving up standards of surgical care. This
Editorial describes the use of Funnel Plots, which are the common
means by which such data are presented, and discusses how the plots
are generated. Cite this article:
Total hip replacement (THR) is a very common
procedure undertaken in up to 285 000 Americans each year. Patient
satisfaction with THR is very high, with improvements in general
health, quality of life, and function while at the same time very
cost effective. Although the majority of patients have a high degree
of satisfaction with their THR, 27% experience some discomfort,
and up to 6% experience severe chronic pain. Although it can be
difficult to diagnose the cause of the pain in these patients, this
clinical issue should be approached systematically and thoroughly.
A detailed history and clinical examination can often provide the
correct diagnosis and guide the appropriate selection of investigations, which
will then serve to confirm the clinical diagnosis made. Cite this article:
A modular femoral head–neck junction has practical
advantages in total hip replacement. Taper fretting and corrosion
have so far been an infrequent cause of revision. The role of design
and manufacturing variables continues to be debated. Over the past
decade several changes in technology and clinical practice might
result in an increase in clinically significant taper fretting and
corrosion. Those factors include an increased usage of large diameter
(36 mm) heads, reduced femoral neck and taper dimensions, greater
variability in taper assembly with smaller incision surgery, and
higher taper stresses due to increased patient weight and/or physical
activity. Additional studies are needed to determine the role of
taper assembly compared with design, manufacturing and other implant
variables. Cite this article:
Osteoporosis and abnormal bone metabolism may prove to be significant
factors influencing the outcome of arthroplasty surgery, predisposing
to complications of aseptic loosening and peri-prosthetic fracture.
We aimed to investigate baseline bone mineral density (BMD) and
bone turnover in patients about to undergo arthroplasty of the hip
and knee. We prospectively measured bone mineral density of the hip and
lumbar spine using dual-energy X-ray absorptiometry (DEXA) scans
in a cohort of 194 patients awaiting hip or knee arthroplasty. We
also assessed bone turnover using urinary deoxypyridinoline (DPD),
a type I collagen crosslink, normalised to creatinine.Aims
Methods
The October 2013 Research Roundup360 looks at: Orthopaedics: a dangerous profession?; Freezing and biomarkers for bone turnover; Herniation or degeneration first?; MARS MRI and metallosis; Programmed cell death in partial thickness cuff tears; Lead glasses for trauma surgery?; Smoking inhibits bone healing; Optimising polyethylene microstructure.
In a time of limited resources, the debate continues
over which types of hip prosthesis are clinically superior and more
cost-effective. Orthopaedic surgeons increasingly need robust economic
evidence to understand the full value of the operation, and to aid
decision making on the ‘package’ of procedures that are available
and to justify their practice beyond traditional clinical preference. In this paper we explore the current economic debate about the
merits of cemented and cementless total hip replacement, an issue
that continues to divide the orthopaedic community. Cite this article:
Arthritis of the hip in the young adult can be a disabling condition. Recent years have witnessed extensive research related to the management of this condition. This article reviews the current status with regard to aetiology, diagnosis and treatment of arthritis of the hip in the young adult.
Cervical spinal disc replacement is used in the management of degenerative cervical disc disease in an attempt to preserve cervical spinal movement and to prevent adjacent disc overload and subsequent degeneration. A large number of patients have undergone cervical spinal disc replacement, but the effectiveness of these implants is still uncertain. In most instances, degenerative change at adjacent levels represents the physiological progression of the natural history of the arthritic disc, and is unrelated to the surgeon. Complications of cervical disc replacement include loss of movement from periprosthetic ankylosis and ossification, neurological deficit, loosening and failure of the device, and worsening of any cervical kyphosis. Strict selection criteria and adherence to scientific evidence are necessary. Only prospective, randomised clinical trials with long-term follow-up will establish any real advantage of cervical spinal disc replacement over fusion.
We report the clinical and radiological outcomes
of a series of contemporary cementless ceramic-on-ceramic total hip
replacements (THRs) at ten years in patients aged ≤ 55 years of
age. Pre- and post-operative activity levels are described. A total
of 120 consecutive ceramic cementless THRs were performed at a single
centre in 110 patients from 1997 to 1999. The mean age of the patients
at operation was 45 years (20 to 55). At ten years, four patients
had died and six were lost to follow-up, comprising ten hips. The
mean post-operative Harris hip score was 94.7 (55 to 100). Radiological
analysis was undertaken in 90 available THRs of the surviving 106
hips at final review: all had evidence of stable bony ingrowth,
with no cases of osteolysis. Wear was undetectable. There were four
revisions. The survival for both components with revision for any
cause as an endpoint was 96.5% (95% confidence interval 94.5 to
98.7). The mean modified University of California, Los Angeles activity
level rose from a mean of 6.4 (4 to 10) pre-operatively to 9.0 (6
to 10) at the ten-year post-operative period. Alumina ceramic-on-ceramic bearings in cementless primary THR
in this series have resulted in good clinical and radiological outcomes
with undetectable rates of wear and excellent function in the demanding
younger patient group at ten years. Cite this article:
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.
We reviewed the literature on the currently available
choices of bearing surface in total hip replacement (THR). We present
a detailed description of the properties of articulating surfaces
review the understanding of the advantages and disadvantages of
existing bearing couples. Recent technological developments in the
field of polyethylene and ceramics have altered the risk of fracture
and the rate of wear, although the use of metal-on-metal bearings has
largely fallen out of favour, owing to concerns about reactions
to metal debris. As expected, all bearing surface combinations have
advantages and disadvantages. A patient-based approach is recommended,
balancing the risks of different options against an individual’s
functional demands. Cite this article:
We prospectively assessed the efficacy of a ceramic-on-metal
(CoM) hip bearing with uncemented acetabular and femoral components
in which cobalt–chrome acetabular liners and alumina ceramic heads
were used. The cohort comprised 94 total hip replacements (THRs) in 83 patients
(38 women and 45 men) with a mean age of 58 years (42 to 70). Minimum
follow-up was two years. All patients had pre- and post-operative
assessment using the Western Ontario and McMaster Universities osteoarthritis
index (WOMAC), Oxford hip score and Short-Form 12 scores. All showed
a statistically significant improvement from three months post-operatively
onwards (all p <
0.001). After two years whole blood metal ion levels were measured and
chromosomal analysis was performed. The levels of all metal ions
were elevated except vanadium. Levels of chromium, cobalt, molybdenum
and titanium were significantly higher in patients who underwent
bilateral THR compared with those undergoing unilateral THR (p <
0.001).
Chromosomal analysis demonstrated both structural and aneuploidy
mutations. There were significantly more breaks and losses than
in the normal population (p <
0.001). There was no significant
difference in chromosomal aberration between those undergoing unilateral
and bilateral procedures (all analyses p ≥ 0.62). The use of a CoM THR is effective clinically in the short-term,
with no concerns, but the significance of high metal ion levels
and chromosomal aberrations in the long-term remains unclear. Cite this article:
We have undertaken a prospective, randomised study to compare conservation of acetabular bone after total hip replacement and resurfacing arthroplasty of the hip. We randomly assigned 210 hips to one of the two treatment groups. Uncemented, press-fit acetabular components were used for both. No significant difference was found in the mean diameter of acetabular implant inserted in the groups (54.74 mm for total hip replacement and 54.90 mm for resurfacing arthroplasty). In seven resurfacing procedures (6.8%), the surgeon used a larger size of component in order to match the corresponding diameter of the femoral component. With resurfacing arthroplasty, conservation of bone is clearly advantageous on the femoral side. Our study has shown that, with a specific design of acetabular implant and by following a careful surgical technique, removal of bone on the acetabular side is comparable with that of total hip replacement.
We retrospectively analysed concentrations of chromium and cobalt ions in samples of synovial fluid and whole blood taken from a group of 92 patients with failed current-generation metal-on-metal hip replacements. We applied acid oxidative digestion to our trace metal analysis protocol, which found significantly higher levels of metal ion concentrations in blood and synovial fluid than a non-digestive method. Patients were subcategorised by mode of failure as either ‘unexplained pain’ or ‘defined causes’. Using this classification, chromium and cobalt ion levels were present over a wider range in synovial fluid and not as strongly correlated with blood ion levels as previously reported. There was no significant difference between metal ion concentrations and manufacturer of the implant, nor femoral head size below or above 50 mm. There was a moderately positive correlation between metal ion levels and acetabular component inclination angle as measured on three-dimensional CT imaging. Our results suggest that acid digestion of samples of synovial fluid samples is necessary to determine metal ion concentrations accurately so that meaningful comparisons can be made between studies.
Lately, concerns have arisen following the use of large metal-on-metal bearings in hip replacements owing to reports of catastrophic soft-tissue reactions resulting in implant failure and associated complications. This review examines the literature and contemporary presentations on current clinical dilemmas in metal-on-metal hip replacement.
The April 2013 Hip &
Pelvis Roundup360 looks at: hip cartilage and magnets; labral repair or resection; who benefits from injection; rotational osteotomy for osteonecrosis; whether ceramic implants risk fracture; dual articulation; and hydroxyapatite.
There has been a recent increase in interest
for non-cemented fixation in total knee arthroplasty (TKA), however
the superiority of cement fixation is an ongoing debate. Whereas the results based on Level III and IV evidence show similar
survivorship rates between the two types of fixation, Level I and
II evidence strongly support cemented fixation. United Kingdom,
Australia, Sweden, and New Zealand registry data show lower failure
rates and greater usage of cemented than non-cemented fixation.
Case series studies have also indicated greater functional outcomes
and lower revision rates among cemented TKAs. Non-cemented fixation
involves more patellofemoral complications, including increased
susceptibility to wear due to a thinner polyethylene bearing on
the cementless metal-backed component. The combination of results
from registry data, prospective randomised studies, and meta-analyses
support the current superiority of cemented fixation in TKAs.
We report the minimum five-year follow-up of 352 primary total hip replacements using the uncemented hydroxyapatite-coated ANCA-Fit femoral component with a modular neck and head. The series comprised 319 patients (212 men, 107 women) with a mean age at operation of 64.4 years (28 to 97). The principal diagnosis was osteoarthritis. A total of 18 patients (21 hips) died before their follow-up at five years, nine patients (11 hips) were lost to follow-up, and four (four hips) declined further follow-up. Patient-reported outcomes have been recorded for 288 patients (316 hips). Their mean Oxford Hip Score improved significantly from 41 points (16 to 57) pre-operatively to 20 points (12 to 44) at five-year follow-up. Radiological assessment showed good bony stability in 98% of implants. There were two cases of aseptic loosening of the femoral component. There were no clinical or radiological complications related to modularity. In our series we did not see the high rate of intra-operative fracture previously reported for this implant. This medium-term follow-up study demonstrates that the clinical outcome of the ANCA-Fit femoral component is, to date, comparable with that of other metaphyseal loading femoral components.