We have analysed from the Finnish Arthroplasty Register the long-term survivorship of the 12 most commonly-used cemented implants between 1980 and 2005 in patients aged 55 years or older with osteoarthritis. Only two designs of femoral component, the Exeter Universal and the Müller Straight femoral component had a survivorship of over 95% at ten years with revision for aseptic loosening as the endpoint. At 15 years of the femoral and acetabular component combinations, only the Exeter Universal/Exeter All-poly implant had a survival rate of over 90% with revision for aseptic loosening as the endpoint. In the subgroup of patients aged between 55 and 64 years, survivorship overall was less than 90% at ten years. The variation in the long-term rates of survival of different cemented hip implants was considerable in patients aged 55 years or older. In those aged between 55 and 64 years, none of the cemented prostheses studied yielded excellent long-term survival rates (≥ 90% at 15 years).
We describe a new technique of reconstruction of the deficient acetabulum in cementless total hip arthroplasty. The outer iliac table just above the deficient acetabulum is osteotomised and slid downwards. We have termed this an iliac sliding graft. Between October 1997 and November 2001, cementless total hip arthroplasty with an iliac sliding graft was performed on 19 patients (19 hips) with acetabular dysplasia. The mean follow-up was 3.4 years (2 to 6). The mean pre-operative Harris hip score was 45.1 which improved significantly to 85.3 at the time of the final follow-up. No patient had post-operative abductor dysfunction. Incorporation of the graft was seen after two to three months in all patients. Resorption of the graft and radiolucencies were infrequent. This technique is a useful alternative to femoral head autografting when the patient’s own femoral head cannot be used.
We hypothesised that the removal of the subchondral
bone plate (SCBP) for cemented acetabular component fixation in
total hip arthroplasty (THA) offers advantages over retention by
improving the cement-bone interface, without jeopardising implant
stability. We have previously published two-year follow-up data
of a randomised controlled trial (RCT), in which 50 patients with
primary osteoarthritis were randomised to either retention or removal
of the SCBP. The mean age of the retention group (n = 25, 13 males)
was 70.0 years ( Cite this article:
Degenerative problems of the hip in patients
with childhood and adult onset neuromuscular disorders can be challenging
to treat. Many orthopaedic surgeons are reluctant to recommend total
hip replacement (THR) for patients with underlying neuromuscular
disorders due to the perceived increased risks of dislocation, implant loosening,
and lack of information about the functional outcomes and potential
benefits of these procedures in these patients. Modular femoral
components and alternative bearings which facilitate the use of
large femoral heads, constrained acetabular components and perhaps
more importantly, a better understanding about the complications
and outcomes of THR in the patient with neuromuscular disorders,
make this option viable. This paper will review the current literature
and our experience with THR in the more frequently encountered neuromuscular
disorders. Cite this article:
There is increasing global awareness of adverse
reactions to metal debris and elevated serum metal ion concentrations
following the use of second generation metal-on-metal total hip
arthroplasties. The high incidence of these complications can be
largely attributed to corrosion at the head-neck interface. Severe
corrosion of the taper is identified most commonly in association
with larger diameter femoral heads. However, there is emerging evidence
of varying levels of corrosion observed in retrieved components
with smaller diameter femoral heads. This same mechanism of galvanic
and mechanically-assisted crevice corrosion has been observed in
metal-on-polyethylene and ceramic components, suggesting an inherent
biomechanical problem with current designs of the head-neck interface. We provide a review of the fundamental questions and answers
clinicians and researchers must understand regarding corrosion of
the taper, and its relevance to current orthopaedic practice. Cite this article:
The results of 140 total hip revision procedures for "non-septic" loosening, dislocation, and fracture of the femoral stem or shaft have been personally reviewed and rated by the Harris method. The minimum follow-up period was six months: thirty-three (24 per cent) showed excellent or good results, seventy-two (51 per cent) showed fair or poor results. Subsequent excision arthroplasty was performed in thirty-one patients. The infection rate for these revision procedures was very high, suggesting that many were already infected at the time of revision, and that every "loose" hip must be assumed to be infected until proved otherwise. The mortality rate of 3 per cent was surprisingly low after more than one major surgical procedure in these elderly patients.
The issues surrounding raised levels of metal
ions in the blood following large head metal-on-metal total hip replacement
(THR), such as cobalt and chromium, have been well documented. Despite
the national popularity of uncemented metal-on-polyethylene (MoP)
THR using a large-diameter femoral head, few papers have reported
the levels of metal ions in the blood following this combination.
Following an isolated failure of a 44 mm Trident–Accolade uncemented
THR associated with severe wear between the femoral head and the
trunnion in the presence of markedly elevated levels of cobalt ions
in the blood, we investigated the relationship between modular femoral head
diameter and the levels of cobalt and chromium ions in the blood
following this THR. A total of 69 patients received an uncemented Trident–Accolade
MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean
age 67.0 years) were recruited and had levels of cobalt and chromium
ions in the blood measured between May and June 2012. The patients
were then divided into three groups according to the diameter of
the femoral head used: 12 patients in the 28 mm group (controls),
18 patients in the 36 mm group and 13 patients in the 40 mm group.
A total of four patients had identical bilateral prostheses in situ
at phlebotomy: one each in the 28 mm and 36 mm groups and two in
the 40 mm group. There was a significant increase in the mean levels of cobalt
ions in the blood in those with a 36 mm diameter femoral head compared
with those with a 28 mm diameter head (p = 0.013). The levels of
cobalt ions in the blood were raised in those with a 40 mm diameter
head but there was no statistically significant difference between
this group and the control group (p = 0.152). The levels of chromium
ions in the blood were normal in all patients. The clinical significance of this finding is unclear, but we
have stopped using femoral heads with a diameter of ≤ 36 mm, and
await further larger studies to clarify whether, for instance, this
issue particularly affects this combination of components. Cite this article:
Fatigue fractures which originate at stress-concentrating voids located at the implant-cement interface are a potential cause of septic loosening of cemented femoral components. Heating of the component to 44°C is known to reduce the porosity of the cement-prosthesis interface. The temperature of the cement-bone interface was recorded intra-operatively as 32.3°C. A simulated femoral model was devised to study the effect of heating of the component on the implant-cement interface. Heating of the implant and vacuum mixing have a synergistic effect on the porosity of the implant-cement interface, and heating also reverses the gradients of microhardness in the mantle. Heating of the implant also reduces porosity at the interface depending on the temperature. A minimum difference in temperature between the implant and the bone of 3°C was required to produce this effect. The optimal difference was 7°C, representing a balance between maximal reduction of porosity and an increased risk of thermal injury. Using contemporary cementing techniques, heating the implant to 40°C is recommended to produce an optimum effect.
Using data from the Norwegian Arthroplasty Register, we have the assessed survival of 17 323 primary Charnley hip prostheses in patients with osteoarthritis based upon the type of cement used for the fixation of the implant. Overall, 9.2% had been revised after follow-up for ten years; 71% of the failures involved aseptic loosening of the femoral component. We observed significantly increased rates of failure for prostheses inserted with CMW1 and CMW3 cements. Using implants fixed with gentamicin-containing Palacos cement as the reference, the adjusted Cox regression failure rate ratios were 1.1 (95% CI 0.9 to 1.4) for implants cemented with plain Palacos, 1.1 (95% CI 0.7 to 1.6) for Simplex, 2.1 (95% 1.5 to 2.9) for gentamicin-containing CMW1, 2.0 (95% CI 1.6 to 2.4) for plain CMW1 and 3.0 (95% CI 2.3 to 3.9) for implants fixed with CMW3 cement. The adjusted failure rate at ten years varied from 5.9% for implants fixed with gentamicin-containing Palacos to 17% for those fixed with CMW3.
We studied the rates of revision for 53 698 primary total hip replacements (THRs) in nine different groups of disease. Factors which have previously been shown to be associated with increased risk of revision, such as male gender, young age, or certain types of uncemented prosthesis, showed important differences between the diagnostic groups. Without adjustment for these factors we observed an increased risk of revision in patients with paediatric hip diseases and in a small heterogeneous ‘other’ group, compared with patients with primary osteoarthritis. Most differences were reduced or disappeared when an adjustment for the prognostic factors was made. After adjustment, an increased relative risk (RR) of revision compared with primary osteoarthritis was seen in hips with complications after fracture of the femoral neck (RR = 1.3, p = 0.0005), in hips with congenital dislocation (RR = 1.3, p = 0.03), and in the heterogenous ‘other’ group. The analyses were also undertaken in a more homogenous subgroup of 16 217 patients which had a Charnley prosthesis implanted with high-viscosity cement. The only difference in this group was an increased risk for revision in patients who had undergone THR for complications after fracture of the femoral neck (RR = 1.5, p = 0.0005). THR for diagnoses seen mainly among young patients had a good prognosis, but they had more often received inferior uncemented implants. If a cemented Charnley prosthesis is used, the type of disease leading to THR seems in most cases to have only a minor influence on the survival of the prosthesis.
Persistent groin pain after seemingly successful
total hip replacement (THR) appears to have become more common.
Recent studies have indicated a high incidence after metal-on-polyethylene
and metal-on-metal conventional THR and it has been documented in
up to 18% of patients after metal-on-metal resurfacing. There are many
causes, including acetabular loosening, stress fracture, and iliopsoas
tendonitis and impingement. The evaluation of this problem requires
a careful history and examination, plain radiographs and an algorithmic approach
to special diagnostic imaging and tests. Non-operative treatment
is not usually successful. Specific operative treatment depending
on the cause of the pain usually involves revision of the acetabular
component, iliopsoas tenotomy or other procedures, and is usually
successful. Here, an appropriate algorithm is described.
It is accepted that resurfacing hip replacement
preserves the bone mineral density (BMD) of the femur better than total
hip replacement (THR). However, no studies have investigated any
possible difference on the acetabular side. Between April 2007 and March 2009, 39 patients were randomised
into two groups to receive either a resurfacing or a THR and were
followed for two years. One patient’s resurfacing subsequently failed,
leaving 19 patients in each group. Resurfaced replacements maintained proximal femoral BMD and,
compared with THR, had an increased bone mineral density in Gruen
zones 2, 3, 6, and particularly zone 7, with a gain of 7.5% (95%
confidence interval (CI) 2.6 to 12.5) compared with a loss of 14.6%
(95% CI 7.6 to 21.6). Resurfacing replacements maintained the BMD
of the medial femoral neck and increased that in the lateral zones
between 12.8% (95% CI 4.3 to 21.4) and 25.9% (95% CI 7.1 to 44.6). On the acetabular side, BMD was similar in every zone at each
point in time. The mean BMD of all acetabular regions in the resurfaced
group was reduced to 96.2% (95% CI 93.7 to 98.6) and for the total
hip replacement group to 97.6% (95% CI 93.7 to 101.5) (p = 0.4863).
A mean total loss of 3.7% (95% CI 1.0 to 6.5) and 4.9% (95% CI 0.8
to 9.0) of BMD was found above the acetabular component in W1 and
10.2% (95% CI 0.9 to 19.4) and 9.1% (95% CI 3.8 to 14.4) medial
to the implant in W2 for resurfaced replacements and THRs respectively.
Resurfacing resulted in a mean loss of BMD of 6.7% (95% CI 0.7 to
12.7) in W3 but the BMD inferior to the acetabular component was
maintained in both groups. These results suggest that the ability of a resurfacing hip replacement
to preserve BMD only applies to the femoral side.
We report 16 cases of erythematous eruption on the skin within the flaps of the surgical incision after primary total hip replacement over an eight-year period. The symptoms began within nine months of operation in 13 hips, and two to three years after in three. Four patients had recurrent episodes. All were treated with antibiotics (15 intravenous, one oral) with complete resolution of the eruption within one to six days. The mean follow-up after the last episode of cellulitis was 27 months (14 to 76). There were no cases of periprosthetic sepsis or other sequelae.
We implanted 51 Metal-Cancellous Cementless Lübeck (MCCL) prostheses into 45 patients with dysplastic hips and followed 49 hips (96.1%) for five to nine years. One had needed revision for stem fracture and one for infection; the clinical outcome of the other 47 hips was assessed using the Merle d’Aubigné and Postel hip score. All hips were either excellent (63%) or good (37%). Three patients (6%) had mild thigh pain at six months, but this had settled within two years. Serial radiographs showed stable fixation with bone ingrowth in all hips, with increased density of the cancellous bone in contact with the implant and some trabecular ingrowth. There was early varus shift of the stem in one hip, but this stabilised in three months. Osteolysis of the femoral cortex was seen in one hip at seven years after surgery, and mild bone resorption due to stress shielding in 31 (63%). Acetabular bone grafting with autogenous bone from the femoral head gave successful support to the socket in 13 hips. The MCCL prosthesis gave satisfactory mid-term results in patients with osteoarthritis secondary to hip dysplasia.