As adverse events related to metal on metal hip
arthroplasty have been better understood, there has been increased
interest in toxicity related to the high circulating levels of cobalt ions.
However, distinguishing true toxicity from benign elevations in
cobalt levels can be challenging. The purpose of this review is
to examine the use of cobalt alloys in total hip arthroplasty, to
review the methods of measuring circulating cobalt levels, to define
a level of cobalt which is considered pathological and to review
the pathophysiology, risk factors and treatment of cobalt toxicity.
To the best of our knowledge, there are 18 published cases where
cobalt metal ion toxicity has been attributed to the use of cobalt-chromium
alloys in hip arthroplasty. Of these cases, the great majority reported
systemic toxic reactions at serum cobalt levels more than 100 μg/L.
This review highlights some of the clinical features of cobalt toxicity,
with the goal that early awareness may decrease the risk factors
for the development of cobalt toxicity and/or reduce its severity. Take home message: Severe adverse events can arise from the release
of cobalt from metal-on-metal arthroplasties, and as such, orthopaedic
surgeons should not only be aware of the presenting problems, but
also have the knowledge to treat appropriately. Cite this article:
T-cells are considered to play an important role in the inflammatory response causing arthroplasty failure. The study objectives were to investigate the composition and distribution of CD4+ T-cell phenotypes in the peripheral blood (PB) and synovial fluid (SF) of patients undergoing revision surgery for failed metal-on-metal (MoM) and metal-on-polyethylene (MoP) hip arthroplasties, and in patients awaiting total hip arthroplasty. In this prospective case-control study, PB and SF were obtained from 22 patients (23 hips) undergoing revision of MoM (n = 14) and MoP (n = 9) hip arthroplasties, with eight controls provided from primary hip osteoarthritis cases awaiting arthroplasty. Lymphocyte subtypes in samples were analysed using flow cytometry.Objectives
Methods
An experimental piglet model induces avascular necrosis (AVN)
and deformation of the femoral head but its secondary effects on
the developing acetabulum have not been studied. The aim of this
study was to assess the development of secondary acetabular deformation
following femoral head ischemia. Intracapsular circumferential ligation at the base of the femoral
neck and sectioning of the ligamentum teres were performed in three
week old piglets. MRI was then used for qualitative and quantitative
studies of the acetabula in operated and non-operated hips in eight
piglets from 48 hours to eight weeks post-surgery. Specimen photographs and
histological sections of the acetabula were done at the end of the
study. Objectives
Methods
Avascular necrosis (AVN) is a serious complication
of high-dose chemotherapy for haematological malignancy in childhood.
In order to describe its incidence and main risk factors and to
evaluate the current treatment options, we reviewed 105 children
with a mean age of 8.25 years (1 to 17.8) who had acute lymphoblastic
or acute myeloid leukaemia, or a non-Hodgkin’s lymphoma. Overall,
eight children (7.6%) developed AVN after a mean of 16.8 months (8
to 49). There were four boys and four girls with a mean age of 14.4
years (9.8 to 16.8) and a total of 18 involved sites, 12 of which
were in the femoral head. All these children were aged >
nine years
(p <
0.001). All had received steroid treatment with a mean cumulative
dose of prednisone of 5967 mg (4425 to 9599) compared with a mean
of 3943 mg (0 to 18 585) for patients without AVN (p = 0.005). No
difference existed between genders and no thrombophilic disorders
were identified. Their initial treatment included 11 core decompressions
and two bipolar hip replacements. Later, two salvage osteotomies
were done and three patients (four hips) eventually needed a total
joint replacement. We conclude that AVN mostly affects the weight-bearing
epiphyses. Its risk increases with age and higher steroid doses.
These high-risk patients may benefit from early screening for AVN. Cite this article:
Adverse reaction to wear and corrosion debris
is a cause for concern in total hip arthroplasty (THA). Modular junctions
are a potential source of such wear products and are associated
with secondary pseudotumour formation. We present a consecutive series of 17 patients treated at our
unit for this complication following metal-on-highly cross-linked
polyethylene (MoP) THA. We emphasise the risk of misdiagnosis as
infection, and present the aggregate laboratory results and pathological
findings in this series. The clinical presentation was pain, swelling or instability.
Solid, cystic and mixed soft-tissue lesions were noted on imaging
and confirmed intra-operatively. Corrosion at the head–neck junction
was noted in all cases. No bacteria were isolated on multiple pre-
and intra-operative samples yet the mean erythrocyte sedimentation
rate was 49 (9 to 100) and C-reactive protein 32 (0.6 to 106) and
stromal polymorphonuclear cell counts were noted in nine cases. Adverse soft–tissue reactions can occur in MoP THA owing to corrosion
products released from the head–neck junction. The diagnosis should
be carefully considered when investigating pain after THA. This
may avoid the misdiagnosis of periprosthetic infection with an unidentified
organism and mitigate the unnecessary management of these cases
with complete single- or two-stage exchange. Cite this article:
A total of 397 hips were randomised to receive
Metasul metal-on-metal (MoM), metal-on-conventional polyethylene (MoP)
or ceramic-on-polyethylene (CoP) bearings using a cemented triple-tapered
polished femoral component (MS-30). There were 129 MoM hips in 123
patients (39 male and 84 female, mean age 63.3 years (40.7 to 72.9)),
137 MoP hips in 127 patients (39 male and 88 female, mean age 62.8
years (24.5 to 72.7)) and 131 CoP hips in 124 patients (51 male
and 73 female, mean age 63.9 years (30.6 to 73.8)). All acetabular
components were cemented Weber polyethylene components with the
appropriate inlay for the MoM articulation. Clinical evaluation
was undertaken using the Harris hip score (HHS) and radiological
assessments were made at two, five and seven years. The HHS and radiological
analysis were available for 341 hips after seven years. The MoM
group had the lowest mean HHS (p = 0.124), a higher rate of revision
(p <
0.001) and a higher incidence of radiolucent lines in unrevised
hips (p <
0.001). In all, 12 revisions had been performed in
12 patients: eight in the MoM group (four for infection, four for
aseptic loosening, three in the MoP group (one each of infection,
dislocation and pain) and one in the CoP group (infection). Our findings reveal no advantage to the MoM bearing and identified
a higher revision rate and a greater incidence of radiolucent lines
than with the other articulations. We recommend that patients with
a 28 mm Metasul MoM bearing be followed carefully. Cite this article:
The June 2013 Shoulder &
Elbow Roundup360 looks at: whether suture anchors are still the gold standard; infection and revision elbow arthroplasty; the variable success of elbow replacements; sliding knots; neurologic cuff pain and the suprascapular nerve; lies, damn lies and statistics; osteoarthritis; and one- or two-stage treatment for the infected shoulder revision.
Compartment syndrome, a devastating consequence
of limb trauma, is characterised by severe tissue injury and microvascular
perfusion deficits. We hypothesised that leucopenia might provide
significant protection against microvascular dysfunction and preserve
tissue viability. Using our clinically relevant rat model of compartment syndrome,
microvascular perfusion and tissue injury were directly visualised
by intravital video microscopy in leucopenic animals. We found that
while the tissue perfusion was similar in both groups (38.8% (standard
error of the mean ( Cite this article:
Dysphagia is a common complication of anterior
surgery of the cervical spine. The incidence of post-operative dysphagia
may be as high as 71% within the first two weeks after surgery,
but gradually decreases during the following months. However, 12%
to 14% of patients may have some persistent dysphagia one year after
the procedure. It has been shown that female gender, advanced age,
multilevel surgery, longer operating time and severe pre-operative
neck pain may be risk factors. Although the aetiology remains unclear
and is probably multifactorial, proposed causes include oesophageal
retraction, prominence of the cervical plate and prevertebral swelling.
Recently, pre-operative tracheal traction exercises and the use
of retropharyngeal steroids have been proposed as methods of reducing
post-operative dysphagia. We performed a systematic review to assess the incidence, aetiology,
risk factors, methods of assessment and management of dysphagia
following anterior cervical spinal surgery. Cite this article:
Treatment for osteoarthritis (OA) has traditionally
focused on joint replacement for end-stage disease. An increasing number
of surgical and pharmaceutical strategies for disease prevention
have now been proposed. However, these require the ability to identify
OA at a stage when it is potentially reversible, and detect small
changes in cartilage structure and function to enable treatment
efficacy to be evaluated within an acceptable timeframe. This has
not been possible using conventional imaging techniques but recent
advances in musculoskeletal imaging have been significant. In this
review we discuss the role of different imaging modalities in the
diagnosis of the earliest changes of OA. The increasing number of
MRI sequences that are able to non-invasively detect biochemical
changes in cartilage that precede structural damage may offer a
great advance in the diagnosis and treatment of this debilitating
condition. Cite this article:
Mesenchymal stem-cell based therapies have been
proposed as novel treatments for intervertebral disc degeneration,
a prevalent and disabling condition associated with back pain. The
development of these treatment strategies, however, has been hindered
by the incomplete understanding of the human nucleus pulposus phenotype
and by an inaccurate interpretation and translation of animal to
human research. This review summarises recent work characterising
the nucleus pulposus phenotype in different animal models and in
humans and integrates their findings with the anatomical and physiological
differences between these species. Understanding this phenotype
is paramount to guarantee that implanted cells restore the native
functions of the intervertebral disc. Cite this article:
The aim of this study was to determine if a change
in antibiotic prophylaxis for routine hip and knee replacement was
associated with an increased risk of acute renal impairment. We identified 238 patients (128 knees and 110 hips) who had received
a single prophylactic dose of 1.5 g cefuroxime before joint replacement.
We compared them with prospectively collected data from 254 patients
(117 knees and 137 hips) who received a single prophylactic dose
of 2 g flucloxacillin and a height- and gender-determined dose of
gentamicin. The primary outcome measure was any new renal impairment
as graded by clinically validated criteria. We identified four patients (1.69%) in the cefuroxime group who
developed renal impairment. All four had mild impairment and all
renal function was normal by the third post-operative day. The incidence
of new-onset renal impairment was significantly higher in the flucloxacillin-and-gentamicin
group at 9.45% (24 patients) (p <
0.001). Three of these patients
remained with acute renal impairment after a week, although the
serum creatinine levels in all subsequently returned to normal. Cite this article:
We report a systematic review and meta-analysis
of the peer-reviewed literature focusing on metal sensitivity testing
in patients undergoing total joint replacement (TJR). Our purpose
was to assess the risk of developing metal hypersensitivity post-operatively
and its relationship with outcome and to investigate the advantages
of performing hypersensitivity testing. We undertook a comprehensive search of the citations quoted in
PubMed and EMBASE: 22 articles (comprising 3634 patients) met the
inclusion criteria. The frequency of positive tests increased after
TJR, especially in patients with implant failure or a metal-on-metal
coupling. The probability of developing a metal allergy was higher
post-operatively (odds ratio (OR) 1.52 (95% confidence interval
(CI) 1.06 to 2.31)), and the risk was further increased when failed
implants were compared with stable TJRs (OR 2.76 (95% CI 1.14 to
6.70)). Hypersensitivity testing was not able to discriminate between
stable and failed TJRs, as its predictive value was not statistically
proven. However, it is generally thought that hypersensitivity testing
should be performed in patients with a history of metal allergy
and in failed TJRs, especially with metal-on-metal implants and
when the cause of the loosening is doubtful.
The treatment of chronic osteomyelitis often
includes surgical debridement and filling the resultant void with antibiotic-loaded
polymethylmethacrylate cement, bone grafts or bone substitutes.
Recently, the use of bioactive glass to treat bone defects in infections
has been reported in a limited series of patients. However, no direct comparison
between this biomaterial and antibiotic-loaded bone substitute has
been performed. In this retrospective study, we compared the safety and efficacy
of surgical debridement and local application of the bioactive glass
S53P4 in a series of 27 patients affected by chronic osteomyelitis
of the long bones (Group A) with two other series, treated respectively
with an antibiotic-loaded hydroxyapatite and calcium sulphate compound
(Group B; n = 27) or a mixture of tricalcium phosphate and an antibiotic-loaded
demineralised bone matrix (Group C; n = 22). Systemic antibiotics
were also used in all groups. After comparable periods of follow-up, the control of infection
was similar in the three groups. In particular, 25 out of 27 (92.6%)
patients of Group A, 24 out of 27 (88.9%) in Group B and 19 out
of 22 (86.3%) in Group C showed no infection recurrence at means
of 21.8 (12 to 36), 22.1 (12 to 36) and 21.5 (12 to 36) months follow-up,
respectively, while Group A showed a reduced wound complication
rate. Our results show that patients treated with a bioactive glass
without local antibiotics achieved similar eradication of infection
and less drainage than those treated with two different antibiotic-loaded
calcium-based bone substitutes. Cite this article:
Corticosteroid use has been implicated in the
development of osteonecrosis of the femoral head (ONFH). The exact mechanism
and predisposing factors such as age, gender, dosage, type and combination
of steroid treatment remain controversial. Between March and July
2003, a total of 539 patients with severe acute respiratory syndrome (SARS)
were treated with five different types of steroid. There were 129
men (24%) and 410 women (76%) with a mean age of 33.7 years (21
to 59). Routine screening was undertaken with radiographs, MRI and/or
CT to determine the incidence of ONFH. Of the 129 male patients with SARS, 51 (39.5%) were diagnosed
as suffering from ONFH, compared with only 79 of 410 female patients
(19.3%). The incidence of ONFH in the patients aged between 20 and
49 years was much higher than that of the group aged between 50
and 59 years (25.9% (127 of 491) Cite this article:
There are several reports clarifying successful results following
open reduction using Ludloff’s medial approach for congenital (CDH)
or developmental dislocation of the hip (DDH). This study aimed
to reveal the long-term post-operative course until the period of
hip-joint maturity after the conventional surgical treatments. A long-term follow-up beyond the age of hip-joint maturity was
performed for 115 hips in 103 patients who underwent open reduction
using Ludloff’s medial approach in our hospital. The mean age at
surgery was 8.5 months (2 to 26) and the mean follow-up was 20.3
years (15 to 28). The radiological condition at full growth of the hip
joint was evaluated by Severin’s classification.Objectives
Methods
The December 2013 Shoulder &
Elbow Roundup360 looks at: Platelet-rich plasma; Arthroscopic treatment of sternoclavicular joint osteoarthritis; Synchronous arthrolysis and cuff repair; Arthroscopic arthrolysis; Regional blockade in the beach chair; Recurrent instability; Avoiding iatrogenic nerve injury in elbow arthroscopy; and Complex reconstruction of total elbow revisions
Large-head metal-on-metal (MoM) total hip replacements
(THR) have given rise to concern. Comparative studies of small-head
MoM THRs over a longer follow-up period are lacking. Our objective
was to compare the incidence of complications such as infection,
dislocation, revision, adverse local tissue reactions, mortality
and radiological and clinical outcomes in small-head (28 mm) MoM
and ceramic-on-polyethylene (CoP) THRs up to 12 years post-operatively. A prospective cohort study included 3341 THRs in 2714 patients.
The mean age was 69.1 years (range 24 to 98) and 1848 (55.3%) were
performed in women, with a mean follow-up of 115 months (18 to 201).
There were 883 MoM and 2458 CoP bearings. Crude incidence rates
(cases/1000 person-years) were: infection 1.3 In conclusion, we found similar results for small-head MoM and
CoP bearings up to ten years post-operatively, but after ten years
MoM THRs had a higher risk of all-cause revision. Furthermore, the
presence of an adverse response to metal debris seen in the small-head
MOM group at revision is a cause for concern. Cite this article: