Aims

Tranexamic acid (TXA) has been shown to reduce blood loss and transfusion requirements in patients undergoing orthopaedic surgery. There remains a lack of prospective evidence for the use of TXA in patients undergoing periacetabular osteotomy (PAO). The purpose of this study was to determine if intravenous (IV) TXA is effective in reducing calculated blood loss and transfusions after PAO.

Aims

This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy.

Aims

Despite declining frequency of blood transfusion and electrolyte supplementation following total joint arthroplasty, postoperative blood analyses are still routinely ordered for these patients. This study aimed to determine the rate of blood transfusion and electrolyte restoration in arthroplasty patients treated with a perioperative blood conservation protocol and to identify risk factors that would predict the need for transfusion and electrolyte supplementation.

Aims

Post-operative migration of cemented acetabular components as measured by radiostereometric analysis (RSA) has a strong predictive power for late, aseptic loosening. Also, radiolucent lines predict late loosening. Migration has been reduced by systemic bisphosphonate treatment in randomised trials of hip and knee arthroplasty. Used as a local treatment, a higher local dose of bisphosphonate can be achieved without systemic exposure. We wished to see if this principle could be applied usefully in total hip arthroplasty (THA).

We have investigated the effect of using tranexamic acid (TXA) during peri-acetabular osteotomy (PAO) on peri-operative blood loss and blood transfusion requirements. In addition we analysed whether the use of TXA was associated with an increased risk of venous thromboembolism (VTE) following this procedure.

A consecutive series of 96 PAOs, performed by a single surgeon, were reviewed. A total of 48 patients received TXA and 48 did not. The TXA group received a continuous infusion of TXA at a rate of 10 mg/kg/h. The primary outcome measure was the requirement for blood transfusion. Secondary outcomes included total blood loss, the decrease in the level of haemoglobin in the blood, the length of hospital stay, and the complications of this treatment.

The mean rate of transfusion was significantly lower in the TXA group (62.5% vs 12.5%, p < 0.001). The mean blood loss was also significantly reduced in the TXA group (1.9 L (standard deviation (sd) 0.9) vs 1.5 L (sd 0.7), p < 0.01). No post-operative episodes of VTE were identified in either group.

The use of TXA reduced the blood loss and the rate of transfusion after PAO significantly, without adverse effects such as an increased rate of VTE.

Cite this article: Bone Joint J 2015;97-B:1604–7.

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: Bone Joint J 2016;98-B:14–20.

Symptomatic cobalt toxicity from a failed total hip replacement is a rare but devastating complication. It has been reported following revision of fractured ceramic components, as well as in patients with failed metal-on-metal articulations. Potential clinical findings include fatigue, weakness, hypothyroidism, cardiomyopathy, polycythaemia, visual and hearing impairment, cognitive dysfunction, and neuropathy. We report a case of an otherwise healthy 46-year-old patient, who developed progressively worsening symptoms of cobalt toxicity beginning approximately six months following synovectomy and revision of a fractured ceramic-on-ceramic total hip replacement to a metal-on-polyethylene bearing. The whole blood cobalt levels peaked at 6521 µg/l. The patient died from cobalt-induced cardiomyopathy. Implant retrieval analysis confirmed a loss of 28.3 g mass of the cobalt–chromium femoral head as a result of severe abrasive wear by ceramic particles embedded in the revision polyethylene liner. Autopsy findings were consistent with heavy metal-induced cardiomyopathy.

We recommend using new ceramics at revision to minimise the risk of wear-related cobalt toxicity following breakage of ceramic components.

Cite this article: Bone Joint J 2013;95-B:31–7.

We matched 78 patients with a loose cemented Charnley Elite Plus total hip replacement (THR) by age, gender, race, prosthesis and time from surgery with 49 patients with a well-fixed stable hip replacement, to determine if poor bone quality predisposes to loosening. Clinical, radiological, biomechanical and bone mineral density indicators of bone quality were assessed.

Patients with loose replacements had more pain, were more likely to have presented with atrophic arthritis and to have a history of fragility fracture, narrower femoral cortices and lower peri-prosthetic or lumbar spine bone mineral density (all t-test, p < 0.01). They also tended to be smokers (chi-squared test, p = 0.08). Vitamin-D deficiency was common, but not significantly different between the two groups (t-test, p = 0.31)

In this series of cemented hip replacements performed between 1994 and 1998, aseptic loosening was associated with poor bone quality. Patients with a THR should be screened for osteoporosis and have regular radiological surveillance.

Many different lengths of stem are available for use in primary total hip replacement, and the morphology of the proximal femur varies greatly. The more recently developed shortened stems provide a distribution of stress which closely mimics that of the native femur. Shortening the femoral component potentially comes at the cost of decreased initial stability. Clinical studies on the performance of shortened cemented and cementless stems are promising, although long-term follow-up studies are lacking. We provide an overview of the current literature on the anatomical features of the proximal femur and the biomechanical aspects and clinical outcomes associated with the length of the femoral component in primary hip replacement, and suggest a classification system for the length of femoral stems.

Cite this article: Bone Joint J 2014;96-B:442-8.

An 81-year-old woman presented with a fracture in the left femur. She had well-fixed bilateral hip replacements and had received long-term bisphosphonate treatment. Prolonged bisphosphonate use has been recently linked with atypical subtrochanteric and diaphyseal femoral fractures. While the current definition of an atypical fracture of the femur excludes peri-prosthetic fractures, this case suggests that they do occur and should be considered in patients with severe osteopenia. Union of the fracture followed cessation of bisphosphonates and treatment with teriparatide. Thus, this case calls into question whether prophylactic intramedullary nailing is sufficient alone to treat early or completed atypical femoral fractures.

The reported prevalence of an asymptomatic slip of the contralateral hip in patients operated on for unilateral slipped capital femoral epiphysis (SCFE) is as high as 40%. Based on a population-based cohort of 2072 healthy adolescents (58% women) we report on radiological and clinical findings suggestive of a possible previous SCFE. Common threshold values for Southwick’s lateral head–shaft angle (≥ 13°) and Murray’s tilt index (≥ 1.35) were used. New reference intervals for these measurements at skeletal maturity are also presented.

At follow-up the mean age of the patients was 18.6 years (17.2 to 20.1). All answered two questionnaires, had a clinical examination and two hip radiographs.

There was an association between a high head–shaft angle and clinical findings associated with SCFE, such as reduced internal rotation and increased external rotation. Also, 6.6% of the cohort had Southwick’s lateral head–shaft angle ≥ 13°, suggestive of a possible slip. Murray’s tilt index ≥ 1.35 was demonstrated in 13.1% of the cohort, predominantly in men, in whom this finding was associated with other radiological findings such as pistol-grip deformity or focal prominence of the femoral neck, but no clinical findings suggestive of SCFE.

This study indicates that 6.6% of young adults have radiological findings consistent with a prior SCFE, which seems to be more common than previously reported.

Cite this article: Bone Joint J 2013;95-B:452–8.

In the majority of patients with slipped upper femoral epiphysis only one hip is involved at primary diagnosis. However, the contralateral hip often becomes involved over time. There are no reliable factors predicting a contralateral slip. Whether or not the contralateral hip should undergo prophylactic fixation is a matter of controversy. We present a number of essential points that have to be considered both when choosing to fix the contralateral hip prophylactically as well as when refraining from surgery and instead following the patients with repeat radiographs.

In this study of 41 patients, we used proteomic, Western blot and immunohistochemical analyses to show that several reactive oxygen species scavenging enzymes are expressed differentially in patients with primary osteoarthritis and those with non-loosening and aseptic loosening after total hip replacement (THR). The patients were grouped as A (n = 16, primary THR), B (n = 10, fixed THR but requiring revision for polyethylene wear) and C (n = 15, requiring revision due to aseptic loosening) to verify the involvement of the identified targets in aseptic loosening. When compared with Groups A and B, Group C patients exhibited significant up-regulation of transthyretin and superoxide dismutase 3, but down-regulation of glutathione peroxidase 2 in their hip synovial fluids. Also, higher levels of superoxide dismutase 2 and peroxiredoxin 2, but not superoxide dismutase 1, catalase and glutathione perioxidase 1, were consistently detected in the hip capsules of Group C patients.

We propose that dysregulated reactive oxygen species-related enzymes may play an important role in the pathogenesis and progression of aseptic loosening after THR.

Metal-on-metal hip resurfacing was performed for developmental dysplasia in 96 hips in 85 patients, 78 in women and 18 in men, with a mean age at the time of surgery of 43 years (14 to 65). These cases were matched for age, gender, operating surgeon and date of operation with a group of patients with primary osteoarthritis who had been treated by resurfacing, to provide a control group of 96 hips (93 patients). A clinical and radiological follow-up study was performed. The dysplasia group were followed for a mean of 4.4 years (2.0 to 8.5) and the osteoarthritis group for a mean of 4.5 years (2.2 to 9.4). Of the dysplasia cases, 17 (18%) were classified as Crowe grade III or IV.

There were five (5.2%) revisions in the dysplasia group and none in the osteoarthritic patients. Four of the failures were due to acetabular loosening and the other sustained a fracture of the neck of femur. There was a significant difference in survival between the two groups (p = 0.02). The five-year survival was 96.7% (95% confidence interval 90.0 to 100) for the dysplasia group and 100% (95% confidence interval 100 to 100) for the osteoarthritic group. There was no significant difference in the median Oxford hip score between the two groups at any time during the study.

The medium-term results of metal-on-metal hip resurfacing in all grades of developmental dysplasia are encouraging, although they are significantly worse than in a group of matched patients with osteoarthritis treated in the same manner.

Narrowing of the femoral neck after resurfacing arthroplasty of the hip has been described previously in both cemented and uncemented hip resurfacing. The natural history of narrowing of the femoral neck is unknown. We retrospectively measured the diameter of the femoral neck in a series of 163 Birmingham hip resurfacings in 163 patients up to a maximum of six years after operation to determine the extent and progression of narrowing.

There were 105 men and 58 women with a mean age of 52 years (18 to 82). At a mean follow-up of five years, the mean Harris hip score was 94.8 (47 to 100) and the mean flexion of the hip 112.5° (80° to 160°). There was some narrowing of the femoral neck in 77% (125) of the patients reviewed, and in 27.6% (45) the narrowing exceeded 10% of the diameter of the neck. A multiple logistic regression analysis showed a significant association (chi-squared test (derived from logistic regression) p = 0.01) of narrowing with female gender and a valgus femoral neck/shaft angle. There was no significant association between the range of movement, position or size of the component or radiological lucent lines and narrowing of the neck (chi-squared test; p = 0.10 (flexion), p = 0.08 (size of femoral component), p = 0.09 (size of acetabular component), p = 0.71 (femoral component angulation), p = 0.99 (lucent lines)). There was no significant difference between the diameter of the neck at a mean of three years (2.5 to 3.5) and that at five years (4.5 to 5.5), indicating that any change in the diameter of the neck had stabilised by three years (sign rank test, p = 0.60).

We conclude that narrowing of the femoral neck which is found with the Birmingham hip resurfacing arthroplasty is in most cases associated with no adverse clinical or radiological outcome up to a maximum of six years after the initial operation.

The aims of this study were to examine the repeatability of measurements of bone mineral density (BMD) around a cemented polyethylene Charnley acetabular component using dual-energy x-ray absorptiometry and to determine the longitudinal pattern of change in BMD during the first 24 months after surgery.

The precision of measurements of BMD in 19 subjects ranged from 7.7% to 10.8% between regions, using a four-region-of-interest model. A longitudinal study of 27 patients demonstrated a transient decrease in net pelvic BMD during the first 12 months, which recovered to baseline at 24 months. The BMD in the region medial to the dome of the component reduced by between 7% and 10% during the first three months, but recovered to approximately baseline values by two years.

Changes in BMD in the pelvis around cemented acetabular components may be measured using dual-energy x-ray absorptiometry. Bone loss after insertion of a cemented Charnley acetabular component is small, transient and occurs mainly at the medial wall of the acetabulum. After two years, bone mass returns to baseline values, with a pattern suggesting a uniform transmission of load to the acetabulum.

We examined the association between patient-related factors and the risk of initial, short- and long-term implant failure after primary total hip replacement. We used data from the Danish Hip Arthroplasty Registry between 1 January 1995 and 31 December 2002, which gave us a total of 36 984 patients. Separate analyses were carried out for three follow-up periods: 0 to 30 days, 31 days to six months (short term), and six months to 8.6 years after primary total hip replacement (long term). The outcome measure was defined as time to failure, which included re-operation with open surgery for any reason.

Male gender and a high Charlson co-morbidity index score were strongly predictive for failure, irrespective of the period of follow-up. Age and diagnosis at primary total hip replacement were identified as time-dependent predictive factors of failure. During the first 30 days after primary total hip replacement, an age of 80 years or more and hip replacement undertaken as a sequela of trauma, for avascular necrosis or paediatric conditions, were associated with an increased risk of failure. However, during six months to 8.6 years after surgery, being less than 60 years old was associated with an increased risk of failure, whereas none of the diagnoses for primary total hip replacement appeared to be independent predictors.