Cemented hemiarthroplasty for neck of femur fractures has been advocated over uncemented hemiarthroplasty due to better post-operative recovery and patient satisfaction. However, studies have shown adverse effects of bone cement on the cardio-respiratory system which may lead to higher morbidity and mortality. Therefore, in some institutes, the use of an uncemented prosthesis has been adopted for patients with a high number of co-morbidities. The aim was to compare early mortality rates for cemented vs. uncemented hemiarthroplasties. Cohort study of displaced intracapsular hip fractures treated with hemiarthroplasty between 1999–2009 at one institute. A total of 3094 hemiarthroplasties performed; out of which 1002(32.4%) were cemented and 2092(67.6%) were uncemented. 48hour and 30day mortality rates for the two groups were compared and a multivariate Cox regression model used to eliminate confounding factors. Significant confounding factor included age, sex, mini mental test score, medical co-morbidities, Nottingham Hip Fracture Score and delay to surgery.Introduction
Method
Hip and knee replacements are common and successful surgeries in orthopaedics. One of the known complications is fat embolism. Cemented implants used in arthroplasty allow good implant fixation and excellent long term results. However this has been associated with an increased incidence of fat embolism. This experimental animal study compared the amount of fat embolism following three different surgeries in 30 Sprague Dawley rats. These surgeries simulated hip replacement procedures and included a control surgery, an
Objective: To develop in-vitro experiments that measure the strain distributions at the bone-implant and bone-cement interface of the acetabular region under physiological loading conditions for cemented and cementless sockets. Experimental model: Four hemi-pelvic specimens of saw bones were used. Following careful placement of six protected precision strain gauges, two specimens were prepared to receive a cemented polyethylene cup (Depuy Charnley Elite 53/28). Another two specimens were prepared and implanted with
Principles of bone preservation and restoration of biomechanical alignment should be followed during revision total hip arthroplasty (THA). Where possible, conservative femoral revision techniques and even reconstructive de-escalation involving using primary stems should be considered. This study aims to investigate the outcome of patients who have undergone conservative femoral revision THA in our Institution. We retrospectively identified patients from our Institution's revision arthroplasty database who had cemented, or
The use of fourth generation ceramic as an orthopaedic biomaterial has proved to be a very efficient and has gained popularity for primary hip surgery in the last 8–10 years. Cumulative percentage probability of revision after 7 years for
In 1823 J. White excised the head. In 1887 a German surgeon replaced the head with ivory. Interposition arthroplasties were common after WW1. Short-stemmed head replacing prosthesis were developed after WW2. Moores and Thompson designed a more stable intramedullary stem. Acetabular erosion was troublesome—and so replacing both surfaces started in the late 1950s using Teflon cup and metal femur. Unfortunately, these quickly became loose due to wear or sepsis. In 1960, Charnley used a polyethylene cup and stainless-steel femur and fixed both with dental cement. This ‘low friction arthroplast’ became a routine procedure after 1961. In the 1970s there were many ‘Charnley look-alike’ prosthesis with similar problems of poly-wear, granulomas and cysts causing bone loss, loosening, breakages and infection. Resurfacing with two thin shells was developed to reduce the foreign material, the bone resection and the cement used. Unfortunately, neck fractures, avascular necrosis and excessive wear of the poly shell were common. Despite operating theatres with laminar flow of sterile air, space suits and improved cementing techniques, the same problems occurred. To avoid poly and cement, Mittelmayer developed a ceramic screw cup, which did not require cement. Although some screws migrated, they did not wear. Because the
When inserting a femoral stem, surgeons make use of many visual and tactile cues to be sure that the implant is correctly sized and well-seated. One such cue is the change of pitch that can be heard when the final femoral broach is inserted. This is known to be important, but has not been widely studied. We set out to analyse the sounds produced during femoral broaching and implant fixation, and to discover whether the absence of these sounds could predict a poor fixation. We recorded the sound of femoral broaching and definitive implant insertion, for twenty
Modular
Press-fit fixation of uncemented acetabular components is increasingly being used for total hip replacement (THR) surgery. This study was aimed to analyse the survival of an established,
Objectives. Implant loosening is the most common reason for revision of total or partial knee replacement, but the patient complains of pain-not a loose implant. It would be a useful diagnostic tool to interrogate the implant to ascertain whether it remains well fixed or not, thus either confirming or eliminating this mode of failure. For such technology to be adopted by manufacturers, it must be extremely low cost and simple to build into an implant. We aim to develop a sensor that meets these requirements and, when embedded in an implant, can provide information on its fixation to the underlying bone. We have previously proven that, through impedance analysis of passive piezoelectric sensors, it is possible for such sensors to determine the cured state of cement with good correlation (0.7) to a surgeon's judgement (Darton et al, 2014). In this study we now look at how the impedance trances of the sensors can be interpreted to distinguish between tibial trays that are securely cemented in sawbone blocks and those with no cement in loose fitting sawbone blocks. Method. Small piezoelectric sensors (12 mm diameter, 0.6 mm thickness) were attached using ethyl cyanoacrylate to the top of a small metal tibial tray analogue and wired to an Impedance Analyzer (AEA Technology Inc). The sensor was swept with an alternating current between 100KHz and 400KHz. Three readings were taken using a custom-built code in MATLAB and an average impedance trace was calculated. A pre-calibrated servo-mechanical testing machine (Instron) was used to carry out a pull-out test of the tray from the sawbone block. The force required to completely disengage the tray was recorded. The same tibial tray was then cemented to the same sawbone block using PMMA. Once cured, the same impedance readings were taken before a pull out test was performed on the cemented case. This was repeated on 6 different sawbone blocks. The impedance plots were differentiated to exaggerate the jagged nature of the impedance trace, representative of multiple modes of vibration following which the mean of their differential values was calculated. The average pull out force for cemented trays was approximately 20 times greater than the
Introduction: Lateral insufficiency fractures following total hip replacements have been reported with the femoral stems positioned in varus, together with osteopenia of the lateral femoral cortex. Any abnormal alignment of the lower limbs, such as genu valgum, will alter the load distribution across the femoral cortices, and repetitive loading during walking will predispose the bones to stress fractures at any stress riser point, such as the tip of a femoral component. Bilateral femoral stress fractures post total hip replacements have not been previously described. Materials and Methods: We present a 55 yr old lady, diagnosed with juvenile idiopathic arthritis aged 5 years, and had undergone bilateral total hip replacements at the age of 29 and 30 years and bilateral knee replacements aged 37 and 42 years. The right hip required revision of the cup 15 years later. The knees were in valgus and the left knee was extremely stiff flexing to just 5 degrees. She presented to us as an emergency with bilateral thigh pain with plain radiographs confirming bilateral peri-prosthetic fractures of the femur at the tip of well fixed femoral components. There had been no history of injury and her hips were functioning well up to this time. Results: The patient required revision of both hips to long stem
Aim: To review the study size and requirements of studies looking at factors affecting outcome following total hip arthroplasty. Background: The orthopaedic literature is full of claims that new products out-perform older ones, cemented and
Conversion of failed femoral components of total hip resurfacing to conventional hip replacement is reportedly a straightforward procedure. There is little published to qualify this and what is available suffers from small study numbers and various combinations pre and post-operative implants. Between 1997 and 2002, the Oswestry Outcome Centre prospectively collected data on 5000 Birmingham Hip Resurfacings (BHRs) performed by 141 surgeons, at 87 hospitals. To date 4526 have survived, 135 died and 165 are lost to follow-up. 174 have been revised, of which 60 were failures of the femoral component. We reviewed modes of failure and post-revision clinical outcomes in this sub-group. Isolated femoral component failure accounted for 60 hips (1.2%). 28 femoral neck fractures, 14 femoral head collapses, 13 femoral component loosenings, 3 avascular necroses (AVN), 1 femoral loosening followed by fracture and 1 dislocation. Mean time to revision surgery was 2.6 years (1.8 years for neck fracture; 3.4 years femoral loosening, head collapse and AVN). All acetabular components were left in situ. At revision surgery 25 cemented, 25 uncemented and 10 unknown femoral prostheses were used with 56 BHR modular heads, 2 custom-made Exeter heads and 2 Thrust Plate heads. 47 patients completed outcome scores post-revision surgery. Median modified Harris Hip Score was 82 (IQ range=63–93) and Merle d’Aubigne score was 14 (IQ= 9.5–15) at a mean follow up of 3.9 years post-revision. The 4526 surviving resurfacings had a median hip score of 96 (IQ=87–100) p≤4.558x10-8 and median Merle score of 17 (IQ=14–18) p≤1.827x10-7. Mean 7.0 years follow up. There was no difference in outcomes between cemented and
Introduction. Melorheostosis is a rare bone dysplasia characterized by its classic radiographic appearance resembling dripping candle wax. The condition was originally described by Leri and Joanny in 1922. Its etiology is not fully known and treatment in most instances has been symptomatic. There are nearly 350 reported cases on melorheostosis, joint replacement has been successfully attempted in the shoulder and knee joint. We describe a case of severe melorheostosis affecting the left hip causing secondary osteo-arthritis, which was treated with a total hip replacement (THR). To the best of our knowledge this is the first reported case of its kind in the World literature. Case history. A 52-year-old male of Indian origin with known melorheostosis of the left leg for over 30 years, presented with symptoms suggestive of severe osteo-arthritis of the left hip. Previously he had been treated for melorheostosis of the knee joint (fig 1a & 1b) with excisions and decompression of the medial femoral condyle. His left hip became more painful over the last few years. He had a fixed flexion deformity of 20° of the hip, severe muscle wasting and the affected leg was 3 cm longer than the right leg. Radiographs (fig 2a & 2b) confirmed the presence of sclerotic new bone in the acetabulum eroding the femoral head. He had the classical dripping candle wax appearance along the medial border of the neck and shaft of the femur. He underwent a THR using a Corail-Pinnacle
One of the most common early complications after hemiarthroplasty is dislocation, with an incidence of 2 to 4%. After dislocation the mortality and morbidity are significantly increased to in excess of 50%. It has been claimed that a bipolar hemiarthroplasty has a lower risk of dislocation than a unipolar implant. In addition it has been suggested that patients with either Parkinson’s disease or a previous stroke are at increased risk of dislocation. We investigated these claims by performing a comprehensive literature search of articles published in the last 40 years and data obtained from our own hip fracture database. From the literature review, 133 reports involving 21,872 patients were retrieved. A further 1235 hip fractures treated by hemiarthroplasty were recorded from our database. 791 (3.4%) dislocations were recorded. Dislocation rate for unipolar prosthesis was higher than bipolar prosthesis (3.9% versus 2.5%). Dislocation rate for posterior surgical approach was higher than for anterior approach (5.1% versus 2.4%). Dislocation rate for cemented prosthesis was 3.6% versus 2.3% in
Rising health costs have seen increased emphasis on cost containment. Outpatient follow-up after total joint arthroplasty is one such accumulating cost. Enthusiastic recent media interest in failing implants and unacceptable waiting lists adds further interest to the area. We wished to determine the current post-operative follow-up practices and views of New Zealand Orthopaedic Surgeons. A postal survey was sent to all New Zealand Orthopaedic Surgeons. The response rate was 83% (131/158). There was wide variation in routine practice and beliefs. For cemented THJRs, 13% of surgeons routinely saw their patients for less than one year, 38% followed their patients for less than five years and 53% continued to see patients indefinitely. Follow-up for uncemented/hybrid prostheses was higher: 8% for <
one year, 29% for <
5 years and 59% indefinitely. A system of periodically re-calling patients for x-rays without necessarily seeing them is used by 20% of surgeons. The most frequent reasons given for follow-up were the detection of osteolysis, wear, loosening and patient symptoms. Similar figures for total and uni-compartmental knee replacements were reported. Almost a third of surgeons reported that they were unable to follow-up their patients as they would like to because of resource limitations within the public health sector. 44% believed that future changes in medico-legal expectations will necessitate longer follow-up of patients. This survey demonstrates wide variation in practice. Higher follow-up rates for
The Exeter V40 cemented polished tapered stem system has demonstrated excellent long-term outcomes. This paper presents a systematic review of the existing literature and reports on a large case series comparing implant fractures between the Exeter V40 series; 125 mm and conventional length stem systems. A systematic literature search was performed adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. In parallel, we performed a retrospective single centre study of Exeter V40 femoral stem prosthetic fractures between April 2003 and June 2020.Aims
Methods