In this study we present our experience with
four generations of uncemented total knee arthroplasty (TKA) from Smith
&
Nephew: Tricon M, Tricon LS, Tricon II and Profix, focusing
on the failure rates correlating with each design change. Beginning
in 1984, 380 Tricon M, 435 Tricon LS, 305 Tricon 2 and 588 Profix
were implanted by the senior author. The rate of revision for loosening
was 1.1% for the Tricon M, 1.1% for the Tricon LS, 0.5% for the
Tricon 2 with a HA coated tibial component, and 1.3% for the Profix
TKA. No loosening of the femoral component was seen with the Tricon
M, Tricon LS or Tricon 2, with no loosening seen of the tibial component
with the Profix TKA. Regarding revision for wear, the incidence
was 13.1% for the Tricon M, 6.6% for the Tricon LS, 2.3% for the
Tricon 2, and 0% for the Profix. These results demonstrate that
improvements in the design of uncemented components, including increased
polyethylene thickness, improved polyethylene quality, and the introduction
of hydroxyapatite coating, has improved the outcomes of uncemented
TKA over time.
The cause of fracture of the femoral neck after hip resurfacing is poorly understood. In order to evaluate the role of avascular necrosis we compared 19 femoral heads retrieved at revision for fracture of the femoral neck and 13 retrieved for other reasons. We developed a new technique of assessing avascular necrosis in the femoral head by determining the percentage of empty osteocyte lacunae present. Femoral heads retrieved as controls at total hip replacement for osteoarthritis and avascular necrosis had 9% ( In the fracture group the percentage of empty lacunae was 71% ( We conclude that fracture after resurfacing of the hip is associated with a significantly greater percentage of empty osteocyte lacunae within the trabecular bone. This indicates established avascular necrosis and suggests that damage to the blood supply at the time of surgery is a potent risk factor for fracture of the femoral neck after hip resurfacing.
In a randomised trial involving 598 patients
with 600 trochanteric fractures of the hip, the fractures were treated with
either a sliding hip screw (n = 300) or a Targon PF intramedullary
nail (n = 300). The mean age of the patients was 82 years (26 to
104). All surviving patients were reviewed at one year with functional
outcome assessed by a research nurse blinded to the treatment used.
The intramedullary nail was found to have a slightly increased mean
operative time (46 minutes ( In summary, both implants produced comparable results but there
was a tendency to better return of mobility for those treated with
the intramedullary nail.
We describe the early results of a prospective study of 100 total ankle replacements (96 patients) at a single centre using the Mobility Total Ankle Replacement. At final review, six patients had died and five ankles (5%) had been revised, two by fusion and three by exchange of components. All remaining patients were reviewed at a minimum of three years. The mean follow-up was 43 months (4 to 63). The three-year survival was 97% (95% confidence interval (CI) 91 to 99). The four-year survival was 93.6% (95% CI 84.7 to 97.4). The portion of bony interface that was visible on plain radiograph was divided into 15 zones and a radiolucent line or osteolytic cavity was seen in one zone in 14 ankles. It was not seen in more than one zone. In five ankles it was >
10 mm in width. This study suggests that the early outcome of ankle replacement is comparable to that of other total joint replacements.
Revision total hip arthroplasty (THA) is projected
to increase by 137% from the years 2005 to 2030. Reconstruction of
the femur with massive bone loss can be a formidable undertaking.
The goals of revision surgery are to create a stable construct,
preserve bone and soft tissues, augment deficient host bone, improve
function, provide a foundation for future surgery, and create a
biomechanically restored hip. Options for treatment of the compromised femur
include: resection arthroplasty, allograft prosthetic composite
(APC), proximal femoral replacement, cementless fixation with a
modular tapered fluted stem, and impaction grafting. The purpose
of this article is to review the treatment options along with their
associated outcomes in the more severe femoral defects (Paprosky types
IIIb and IV) in revision THA.
We examined prospectively collected data from 6782 consecutive hip fractures and identified 327 fractures in 315 women aged ≤65 years. We report on their demographic characteristics, treatment and outcome and compare them with a cohort of 4810 hip fractures in 4542 women aged >
65 years. The first significant increase in age-related incidence of hip fracture was at 45, rather than 50, which is when screening by the osteoporosis service starts in most health areas. Hip fractures in younger women are sustained by a population at risk as a result of underlying disease. Mortality of younger women with hip fracture was 46 times the background mortality of the female population. Smoking had a strong influence on the relative risk of ‘early’ (≤ 65 years of age) fracture. Lag screw fixation was the most common method of operative treatment. General complication rates were low, as were re-operation rates for cemented prostheses. Kaplan-Meier implant survivorship of displaced intracapsular fractures treated by reduction and lag screw fixation was 71% (95% confidence interval 56 to 81) at five years. The best form of treatment remains controversial.
The survivorship of contemporary resurfacing arthroplasty of the hip using metal-on-metal bearings is better than that of first generation designs, but short-term failures still occur. The most common reasons for failure are fracture of the femoral neck, loosening of the component, osteonecrosis of the femoral head, reaction to metal debris and malpositioning of the component. In 2008 the Australian National Joint Registry reported an inverse relationship between the size of the head component and the risk of revision in resurfacing hip arthroplasty. Hips with a femoral component size of ≤ 44 mm have a fivefold increased risk of revision than those with femoral components of ≥ 55 mm irrespective of gender. We have reviewed the literature to explore this observation and to identify possible reasons including the design of the implant, loading of the femoral neck, the orientation of the component, the production of wear debris and the effects of metal ions, penetration of cement and vascularity of the femoral head. Our conclusion is that although multifactorial, the most important contributors to failure in resurfacing arthroplasty of the hip are likely to be the design and geometry of the component and the orientation of the acetabular component.
Early failure associated with adverse reactions to metal debris is an emerging problem after hip resurfacing but the exact mechanism is unclear. We analysed our entire series of 660 metal-on-metal resurfacings (Articular Surface Replacement (ASR) and Birmingham Hip Resurfacing (BHR)) and large-bearing ASR total hip replacements, to establish associations with metal debris-related failures. Clinical and radiological outcomes, metal ion levels, explant studies and lymphocyte transformation tests were performed. A total of 17 patients (3.4%) were identified (all ASR bearings) with adverse reactions to metal debris, for which revision was required. This group had significantly smaller components, significantly higher acetabular component anteversion, and significantly higher whole concentrations of blood and joint chromium and cobalt ions than asymptomatic patients did (all p <
0.001). Post-revision lymphocyte transformation tests on this group showed no reactivity to chromium or cobalt ions. Explants from these revisions had greater surface wear than retrievals for uncomplicated fractures. The absence of adverse reactions to metal debris in patients with well-positioned implants usually implies high component wear. Surgeons must consider implant design, expected component size and acetabular component positioning in order to reduce early failures when performing large-bearing metal-on-metal hip resurfacing and replacement.
The aim of our study was to investigate whether placing of the femoral component of a hip resurfacing in valgus protected against spontaneous fracture of the femoral neck. We performed a hip resurfacing in 20 pairs of embalmed femora. The femoral component was implanted at the natural neck-shaft angle in the left femur and with a 10° valgus angle on the right. The bone mineral density of each femur was measured and CT was performed. Each femur was evaluated in a materials testing machine using increasing cyclical loads. In specimens with good bone quality, the 10° valgus placement of the femoral component had a protective effect against fractures of the femoral neck. An adverse effect was detected in osteoporotic specimens. When resurfacing the hip a valgus position of the femoral component should be achieved in order to prevent fracture of the femoral neck. Patient selection remains absolutely imperative. In borderline cases, measurement of bone mineral density may be indicated.
We present the results of 90 consecutive children with displaced fractures of the forearm treated by elastic stable intramedullary nailing with a mean follow-up of 6.6 months (2.0 to 17.6). Eight (9%) had open fractures and 77 (86%) had sustained a fracture of both bones. The operations were performed by orthopaedic trainees in 78 patients (86%). All fractures healed at a mean of 2.9 months (1.1 to 8.7). There was one case of delayed union of an ulnar fracture. An excellent or good functional outcome was achieved in 76 patients (84%). There was no statistical difference detected when the grade of operating surgeon, age of the patient and the diaphyseal level of the fracture were correlated with the outcome. A limited open reduction was required in 40 fractures (44%). Complications included seven cases of problematic wounds, two transient palsies of the superficial radial nerve and one case each of malunion and a post-operative compartment syndrome. At final follow-up, all children were pain-free and without limitation of sport and play activities. Our findings indicate that the functional outcome following paediatric fractures of the forearm treated by elastic stable intramedullary nailing is good, without the need for anatomical restoration of the radial bow.
We describe the medium-term results of a prospective study of 200 total ankle replacements at a single-centre using the Scandinavian Total Ankle Replacement. A total of 24 ankles (12%) have been revised, 20 by fusion and four by further replacement and 27 patients (33 ankles) have died. All the surviving patients were seen at a minimum of five years after operation. The five-year survival was 93.3% (95% confidence interval (CI) 89.8 to 96.8) and the ten-year survival 80.3% (95% CI 71.0 to 89.6). Anterior subluxation of the talus, often seen on the lateral radiograph in osteoarthritic ankles, was corrected and, in most instances, the anatomical alignment was restored by total ankle replacement. The orientation of the tibial component, as seen on the lateral radiograph, also affects the position of the talus and if not correct can hold the talus in an abnormal anterior position. Subtalar arthritis may continue to progress after total ankle replacement. Our results are similar to those published previously.
We present two cases of metastatic lung cancer which occurred at the site of a previously united tibial fracture. Both patients were treated with a locked intramedullary nail. The patients presented with metastases at the site of their initial fracture approximately 16 and 13 months after injury respectively. We discuss this unusual presentation and review the relevant literature. We are unaware of any previous reports of a metastatic tumour occurring at the site of an orthopaedic implant used to stabilise a non-pathological fracture. These cases demonstrate the similar clinical presentation of infection and malignancy: a diagnosis which should always be considered in such patients.
Iontophoresis is a novel technique which may be used to facilitate the movement of antibiotics into the substance of bone using an electrical potential applied externally. We have examined the rate of early infection in allografts following application of this technique in clinical practice. A total of 31 patients undergoing revision arthroplasty or surgery for limb salvage received 34 iontophoresed sequential allografts, of which 26 survived for a minimum of two years. The mean serum antibiotic levels after operation were low (gentamicin 0.37 mg/l (0.2 to 0.5); flucloxacillin 1 mg/l (0 to 1) and the levels in the drains were high (gentamicin 40 mg/l (2.5 to 131); flucloxacillin 17 mg/l (1 to 43). There were no early deep infections. Two late infections were presumed to be haemotogenous; 28 of the 34 allografts were retained. In 12 patients with pre-existing proven infection further infection has not occurred at a mean follow-up of 51 months (24 to 82).
We present a retrospective study of patients suffering from a variety of benign tumours in whom external fixators were used to treat deformity and limb-length discrepancy, and for the reconstruction of bone defects. A total of 43 limbs in 31 patients (12 male and 19 female) with a mean age of 14 years (2 to 54) were treated. The diagnosis was Ollier’s disease in 12 limbs, fibrous dysplasia in 11, osteochondroma in eight, giant cell tumour in five, osteofibrous dysplasia in five and non-ossifying fibroma in two. The lesions were treated in the tibia in 19 limbs, in the femur in 16, and in the forearm in eight. The Ilizarov frame was used in 25 limbs, the Taylor Spatial Frame in seven, the Orthofix fixator in six, the Monotube in four and the Heidelberg fixator in one. The mean follow-up was 72 months (22 to 221). The mean external fixation period was 168 days (71 to 352). The mean external fixation index was 42 days/cm (22.2 to 102.0) in the 22 patients who required limb lengthening. The mean correction angle for those with angular deformity was 23° (7° to 45°). At final follow-up all patients had returned to normal activities. Four patients required a second operation for recurrent deformity of further limb lengthening. Local recurrence occurred in one patient, requiring further surgery.
A modular layered acetabular component (metal-polyethylene-ceramic) was developed in Japan for use in alumina ceramic-on-ceramic total hip replacement. Between May 1999 and July 2000, we performed 35 alumina ceramic-on-ceramic total hip replacements in 30 consecutive patients, using this layered component and evaluated the clinical and radiological results over a mean follow-up of 5.8 years (5 to 6.5). A total of six hips underwent revision, one for infection, two for dislocation with loosening of the acetabular component, two for alumina liner fractures and one for component dissociation with pelvic osteolysis. There were no fractures of the ceramic heads, and no loosening of the femoral or acetabular component in the unrevised hips was seen at final follow-up. Osteolysis was not observed in any of the unrevised hips. The survivorship analysis at six years after surgery was 83%. The layered acetabular component in our experience, has poor durability because of unexpected mechanical failures including alumina liner fracture and component dissociation.
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.
We assessed the outcome of patients with Vancouver type B2 and B3 periprosthetic fractures treated with femoral revision using an uncemented extensively porous-coated implant. A retrospective clinical and radiographic assessment of 22 patients with a mean follow-up of 33.7 months was performed. The mean time from the index procedure to fracture was 10.8 years. There were 17 patients with a satisfactory result. Complications in four patients included subsidence in two, deep sepsis in one, and delayed union in one. Concomitant acetabular revision was required in 19 patients. Uncemented extensively porous-coated femoral stems incorporate distally allowing stable fixation. We found good early survival rates and a low incidence of nonunion using this implant.
Inflammatory pseudotumours occasionally occur after metal-on-metal hip resurfacing and often lead to revision. Our aim was to determine the severity of this complication by assessing the outcome of revision in these circumstances and by comparing this with the outcome of other metal-on-metal hip resurfacing revisions as well as that of matched primary total hip replacements. We identified 53 hips which had undergone metal-on-metal hip resurfacing and required revision at a mean of 1.59 years (0.01 to 6.69) after operation. Of these, 16 were revised for pseudotumours, 21 for fracture and 16 for other reasons. These were matched by age, gender and diagnosis with 103 patients undergoing primary total hip replacement with the Exeter implant. At a mean follow-up of three years (0.8 to 7.2) the outcome of metal-on-metal hip resurfacing revision for pseudotumour was poor with a mean Oxford hip score of 20.9 ( The outcome of revision for pseudotumour is poor and consideration should be given to early revision to limit the extent of the soft-tissue destruction. The outcome of resurfacing revision for other causes is good.
The early designs of hip resurfacing implants suffered high rates of early failure, making it impossible to obtain valuable mid-term radiostereophotogrammetric (RSA) results. The metal-on-metal Birmingham Hip Resurfacing arthroplasty has shown promising mid-term results and we present here the first mid-term RSA analysis of a hip resurfacing implant. The analysis was performed in 19 hips at five years post-operatively. The mean acetabular component translation and rotation, and femoral component translation were compared with the previous RSA measurements at two and six months, and one and two years. There was no statistical significance (