Recently, the use of metal-on-metal articulations
in total hip arthroplasty (THA) has led to an increase in adverse
events owing to local soft-tissue reactions from metal ions and
wear debris. While the majority of these implants perform well,
it has been increasingly recognised that a small proportion of patients
may develop complications secondary to systemic cobalt toxicity
when these implants fail. However, distinguishing true toxicity
from benign elevations in cobalt ion levels can be challenging. The purpose of this two part series is to review the use of cobalt
alloys in THA and to highlight the following related topics of interest:
mechanisms of cobalt ion release and their measurement, definitions
of pathological cobalt ion levels, and the pathophysiology, risk factors
and treatment of cobalt toxicity. Historically, these metal-on-metal
arthroplasties are composed of a chromium-cobalt articulation. The release of cobalt is due to the mechanical and oxidative
stresses placed on the prosthetic joint. It exerts its pathological
effects through direct cellular toxicity. This manuscript will highlight the pathophysiology of cobalt
toxicity in patients with metal-on-metal hip arthroplasties. Take home message: Patients with new or evolving hip symptoms
with a prior history of THA warrant orthopaedic surgical evaluation.
Increased awareness of the range of systemic symptoms associated
with cobalt toxicity, coupled with prompt orthopaedic intervention, may
forestall the development of further complications. Cite this article:
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:
Modified posterior approach and its effect on stability and functional outcome in total hip arthroplasty. A retrospective comparative evaluation was done to assess the functional outcome and rate of dislocation in 233 hips (Group A) operated before 2007 by convention posterior approach and 567 hips (Group B) were operated by modified posterior approach.(2007–2011) In this modified posterior approach technique, 2–3 stay sutures (non-absorbale Nylon) are applied in the piriformis tendon, short external rotator and proximal part of Quadratous muscle. Then a conjoint- myocapsular sleeve is raised by starting cutting (with cautery) linearly over the capsule with adherent fibers of gluteus minimus to piriformis tendon, short rotators and part of quadratus to expose and dislocate the head. After inserting the definite prosthesis, upper part of sleeve (capsule, piriformis tendon) is sutured with same nonabsorbable Nylon at the lower part of tip of greater trochanter by passing through the bone with needle or by drilling the bone; lower part of the sleeve is tied with lateral trochanteric bone. Additional stability to repair was given by closing the tendinous part of the gluteus maximus by horizontal cross mattress sutures up its attachment to the proximal femoral shaft.Background:
Material & Methods:
Role of intra-articular Tranexamic acid in total knee replacement arthroplasty Prospective evaluation was done to see the effect of intra-articular Tranexamic acid on blood loss in 60 patients (120 knees) undergoing total knee arthroplasty. All the patients were operated by one surgeon with same technique by using same implants. Patients were randomly injected 1500 mg/20 ml of Tranexamic acid on one side of the knee only. Nothing was injected on the contra lateral knee. Evaluation was done for swelling and the amount of blood loss in the drain.Background:
Materials and methods
Symptomatic hip osteonecrosis is a disabling
condition with a poorly understood aetiology and pathogenesis. Numerous
treatment options for hip osteonecrosis are described, which include
non-operative management and joint preserving procedures, as well
as total hip replacement (THR). Non-operative or joint preserving
treatment may improve outcomes when an early diagnosis is made before
the lesion has become too large or there is radiographic evidence
of femoral head collapse. The presence of a crescent sign, femoral
head flattening, and acetabular involvement indicate a more advanced-stage
disease in which joint preserving options are less effective than
THR. Since many patients present after disease progression, primary
THR is often the only reliable treatment option available. Prior
to the 1990s, outcomes of THR for osteonecrosis were poor. However,
according to recent reports and systemic reviews, it is encouraging
that with the introduction of newer ceramic and/or highly cross-linked
polyethylene bearings as well as highly-porous fixation interfaces,
THR appears to be a reliable option in the management of end-stage
arthritis following hip osteonecrosis in this historically difficult
to treat patient population. Cite this article:
