Austin Moore cervicocephalic prostheses have been a therapeutical option for femoral neck fractures in patients with a reduced general condition for many years. Since treatments other than total hip arthroplasties have also been included in National arthroplasty registers during the last decade, adequate reference data for comparative analyses have recently become available. Based on a standardised methodology, a comprehensive literature analysis of clinical literature and register reports was conducted. On the one hand, the datasets were examined with regard to validity and the occurrence of possible bias factors, on the other hand, the objective was to compile a summary of the data available. The main criterion is the indicator of Revision Rate. The definitions used with respect to revisions and the methodology of calculations are in line with the usual standards of international arthroplasty registers.Introduction
Materials and Methods
Data was collected on 139 eligible patients a minimum of 18 months post surgery who had had 2 or more ligaments reconstructed. 63 patients were available for clinical follow up. It is the largest single surgeon series studied. 27% of injuries were high energy traffic accidents. 73% were low energy, mainly sports related. 63% of patients were delayed referrals to our unit. Of these nearly 48% had already undergone knee surgery, often more than 6 months post injury. 17% of all cases presented with failed ligament reconstructions. Of those patients followed up 19% were operated upon within 3 weeks of injury, 56% were delayed reconstructions with a mean time to surgery of 21 months and 25% were revision reconstructions. Time to follow up ranged from 18 months to 10 years. The median KOS ADL, KOS Sports Activity and Lysholm scores for uni-cruciate surgery were all better than those for bi-cruciate surgery. All results were better for acute rather than chronic cases, which in turn were better than those for revision cases. The Tegner score showed that only acute uni-cruciate reconstructions returned to their pre-injury level. TELOS stress radiographs demonstrated a mean post drawer of 5.9 mm side-to-side difference after reconstructions involving the PCL. IKDC grades showed 6% of knees were normal and 57% were nearly normal. 37% required further surgery, mainly to increase movement or for hardware removal. There was 1 deep infection and 2 cases of thrombosis. There were no vascular complications but 2 had transient nerve injuries. Multi-ligament surgery can produce good functional outcomes but the knee is never normal. There is an increased risk of PCL laxity post op. Early referral to a specialist unit is suggested as delayed referral to a specialist unit potentially subjects the patient to unnecessary surgery and may affect outcome.
The key factors in Tissue Engineering are multipotent stem cells, growth factors (necessary to manipulate cell destiny) and scaffolds (3D constructs which support the growing tissue). Mesenchymal stem cells are the most important part of this equation, and it is procurement and manipulation of these that lies at the heart of tissue engineering. Luckily, mensenchymal stem cells can be obtained from many tissues, including synovium, bone marrow and periosteum. The use of bioreactors to optimise culture conditions and improve cell viability provides an opportunity to control stem cell destiny. Various Tissue Engineering strategies exist: manipulating cells in situ with osteogenic growth factors, such as BMP; implanting whole tissue grafts; and the use of Gene therapy. The tissues that concern orthopaedic surgeons are very diverse and no single tissue engineered construct will be able to fulfil all our clinical needs. Tissue engineering of articular cartilage is very difficult technically, but once accomplished will revolutionalise practice. The challenge lies in being able to produce cartilage as similar to native hyaline cartilage as possible. Although promising, ACI, using culture expanded cells, is able at best to produce hyaline-like cartilage but not the real thing. Multipotent mesenchymal stem cells are being used in this field. Even simply injecting these intraarticularly has been shown to retard the progression of OA in animal models. When attempting to regenerate meniscal cartilage, the mechanical properties of the scaffold become crucial, as the biomechanics of the knee are highly hostile. Ligaments and tendons, though the least complex tissues architecturally, have very high tensile properties which will be hard to replicate. The challenging aspects of Orthopaedic Tissue Engineering are manifold, yet the field itself is growing in leaps and bounds. Despite some initial setbacks, the new developments in this discipline are very encouraging.
By contrast, worldwide Register data refer to 733,000 primary operations, i.e. approximately 10 times as many as sample-based datasets. In general, sample-based datasets present higher revision rates than register data. The deviations are high, with a maximum factor of 64 for hip stems. Whereas the AAHKS survey exhibits lower deviations than the monocentre trials, they are still too high for this data collection tool being considered as reliable and safe to provide valid data for general conclusions. The incidence of implant fractures after total hip arthroplasty in pooled worldwide arthroplasty register datasets is 304 fractures per 100.000 implants. In other words, one out of 323 patients has to undergo revision surgery due to an implant fracture after THA in their lifetime.
For the detection of rare, but severe complications like implant fractures sample-based studies achieve the goal of providing accurate figures only to a very limited extent, even if the samples are large. Here, too, comprehensive national arthroplasty registers are the most suitable tool to identify such incidents and calculate reliable figures. Contrary to the prevalent opinion, implant fractures still are a relevant problem in arthroplasty.
Mortality after hip fractures in the elderly is one of the most important patient outcome measures. Sub-clinical thyroid dysfunction is common in the elderly population. This is a prospective study of 131 elderly patients with a mean (SD) age of 82.0 (8.9) years (range: 61–94) admitted consecutively to our trauma unit. The aim of the study was to determine the prevalence of sub-clinical thyroid dysfunction in an elderly cohort of patients with hip fracture and to determine if this affects the one year mortality. There were three times more women (n=100) than men (n=31) in this cohort. All patients underwent surgical treatment for the hip fracture. The prevalence of sub-clinical hypothyroidism (TSH >
5.5 mU/L) was15% (n=20) and of sub-clinical hyperthyroidism (TSH <
0.35 mU/L) was 3% (n=4). Overall 18% (n=24) of patients had a subclinical thyroid dysfunction. The twelve month mortality was 27% (n=36). Age, gender, heart rate at admission, pre-existing Coronary Heart Disease, ASA grade and presence of overt or subclinical thyroid dysfunction were analysed for association with twelve month mortality using a forward stepwise logistic regression analysis. Only ASA grade was found to significantly affect mortality at twelve months ( We conclude that sub-clinical thyroid dysfunction does not affect the one year mortality in elderly patients treated surgically for hip fracture.
The average revision rate in peer reviewed literature is significantly lower than in arthroplasty register data-sets. Studies published by the inventor of an implant tend to show superior outcome compared to independent publications and Arthroplasty Register data. Factors of 4 to more than 10 have been found, which has a significant impact for the results of Metaanalyses. When an implant is taken from the market or replaced by a successor there is a significant decrease in publications, which limits the detection of failure mechanisms such as PE wear or insufficient locking mechanisms. The final statement made about the product under investigation seem to follow a certain mainstream.
The published results from clinical follow up studies have been compared to Arthroplasty register Results: Results: 24% of all papers were published by the inventor of the implant. These publications show a 3,4 times lower revision rate compared to independent studies and a 4,6 times lower revision rate compared to Register based publications. The cumulative revision rate per 100 observed component years of register based publications is 1,36 times higher compared to independent clinical studies. The difference is statistically not significant. Pooling the published data from all follow up studies the impact of the studies published by the inventor leads to a statistically significant bias.
Arthroplasty Register data are able to detect bias factors and lead to a better quality of assessments concerning the outcome of arthroplasty.
The growth of the patients was an average 17cm. The graft diameters did not change despite large changes in graft length (average 145%). Most of the length gain was in the femur.
Causation: 7 cases:direct trauma [5: associated with MCL tears (1 chronic overload from triple-jump),1:a blow to front of knee, 1:chronic from kneeling] 4 cases: Knee replacement- related [irritation from osteophyte 1; implant-related 3] 3 cases: irritation from medial meniscal sutures [2: Fast-Fix; 1: in:out] 1 case: surgery induced neuroma in arthrotomy wound 1 case: irritation by an enlarging cyst In all cases the time to make the diagnosis was prolonged. All had pain, which on close questioning was ‘neuritic’ [burning] in approximately 2/3. It was exceedingly well localized in all. Altered sensation in the appropriate distribution was noted by the patient in 3 cases, but shown in 5 cases on examination. A positive Tinel test was present in all cases. In approximately half of cases ultrasound plus diagnostic injection of local anaesthetic [+/− steroid] was useful. However 15 of the 16 came to surgery in which a neurolysis or removal of neuroma, in 3 cases, [all confirmed on histology] was undertaken plus the underlying causative factor dealt with eg excision of osteophyte or scar. One case settled [90% better according to patient] after ultrasound-guided injection of a prepatellar bursa which was irritating the infrapatellar branch of the nerve. Of the 15 who had had surgery 12 had complete resolution of symptoms.
Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting 350,000 people in the UK. Within synovial joints, synoviocytes form a destructive pannus that degrades articular cartilage and bone. Synovial fluid glutamate levels increase 54 fold in RA patients and are also elevated in animal models of inflammatory and osteoarthritis. To determine whether elevated glutamate levels contribute to RA pathology we investigated which synovial joint tissues express glutamate receptors and whether glutamate stimulation influences synovio-cyte phenotype. Various glutamate receptor mRNAs (NMDAR1, KA1, AMPAGluR2, AMPA GluR3, mGluR4) were expressed in tissues of the rat knee. All receptors were expressed in the patella. The fibrocartilagenous menis-cus and articular cartilage chondrocytes expressed mGluR4 and both AMPA receptor subunits. Human synoviocytes expressed NMDAR1 and KA1 mRNA. To determine whether glutamate receptors were functional in human synoviocytes, cells were preloaded with a fluorescent indicator of intracellular calcium (iCa 2+) and stimulated with glutamate or specific agonists (NMDA or kainate, 500mM). Glutamate stimulated release of iCa2+ in 25% of synoviocytes whereas NMDA and Kainate each stimulated 15% of cells. NMDA responses increased to 57% in the absence of Mg2+ consistent with the inhibitory effect of Mg2+ on this receptor. To determine whether activation of glutamate receptors can influence human synoviocyte phenotype, we cultured synoviocytes in various glutamate concentrations (50mM to 2mM) and measured effects of glutamate receptor antagonists on release of a proinflammatory cytokine (IL-6) and degradative enzymes (MMP2 and 9). In some RA patients, glutamate stimulation increased synoviocyte pro MMP-2 release. TIMP1 and TIMP2 release were not affected by glutamate stimulation or co-treatment with receptor antagonists. IL-6 expression varied greatly in human synoviocytes derived from different RA patients (0–120pg/ml media). However, the AMPA/KA receptor antagonist NBQX significantly reduced IL-6 release at all glutamate concentrations. This inhibition was greater than that by CFM2 (AMPAR antagonist), indicating that activation of kainate receptors in human synoviocytes may induce IL-6 release. We conclude that glutamate receptors are functional in human synoviocytes and regulate release of MMP-2 and IL-6 Thus glutamatergic signalling may contribute to RA pathology and represent a new therapeutic target.
In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source.
Mosaicplasty 100 consecutive patients aged 15–45 with a symptomatic articular cartilage lesion in the knee suitable for cartilage repair were randomised at arthroscopic assessment to undergo either mosaicplasty or ACI. 42 patients underwent mosaicplasty, 58 had ACI. Mean age at time of surgery was 31 years and the average defect size 4. 66 cm2. 46% of the defects were post-traumatic, 19% had osteochondritis dissecans, 14% had chondromalacia patella and 16% had lesions of unknown aetiology. 53% had a medial femoral condyle lesion, 25% patella, 18% lateral femoral condyle, 3% trochlea and there was one defect of the lateral tibial plateau. The mean duration of symptoms was 7. 2 years and the average number of previous operations (excluding arthroscopies) was 1. 5. Only 6 patients had no prior surgical interventions to the affected knee. The mean follow-up was 1. 7 years. Patients were evaluated using Modified Cincinnati and Stanmore Functional rating systems, visual analogue scores and clinical assessment. Arthroscopy and biopsy was performed at one year and repair assessed with the International Cartilage Repair Society grading system. Clinical results at one year showed 70% of mosaic-plasty patients and 87% of ACI patients had a good or excellent result. Arthroscopy at one year demonstrated more complete healing in ACI patients. Eleven (26%) of the mosaicplasty group subsequently failed clinically and arthroscopically, with peak failure at 2 years. At one year follow-up, both techniques of articular cartilage repair can be useful in selected patients. ACI is preferred for lesions of the patella. Long-term follow-up is needed to assess the durability of articular cartilage repair using these methods, in particular mosaicplasty which showed signs of progressive failure over 2 years.
Autologous Chondrocyte Implantation’ (ACI) is a cartilage repair technique that involves implantation of cultured chondrocytes beneath a membrane of autologous periosteum. In this study a porcine biodegradable membrane was also used to assess its effectiveness. The aim is to restore articular cartilage to symptomatic defects, rather than initiating a fibrocartilagenous repair. We undertook a prospective study of 125 consecutive patients who underwent ACI. Average age at the time of surgery was 30. 9 years (range 14 – 49), 55% of patients were male. The average size of the defect was 4. 35 cm². 44% of defects were attributable to known traumatic incidents, 2 1 % had osteochondritis dessicans, 18% chondromalacia patella, 12% had defects of unknown aetiology and 5% other. The average duration of symptoms prior to this surgery was 7. 16 years. The mean number of previous operations (excluding arthroscopies) was 1. 6. Only 9 patients had no previous major surgery to the affected knee. 44% had defects of the medial femoral condyle, 31% patella, 20% lateral femoral condyle and 5% had a trochlea lesion. 26% of the defects were covered with periosteum and 74% with a porcine collagen membrane (chondrogide) Minimum follow-up was six months, 70 patients had minimum follow-up of one year. Mean follow-up 18 months. Patients were assessed using Modified Cincinnati and Stanmore Functional rating systems, visual analogue scores and clinical evaluation. Arthroscopy and biopsy was performed at one year and the repair assessed using the International Cartilage Research Society grading system. At one year follow-up overall 41 % patients had an excellent result, 48% good, 8% fair and 3% poor. For defects of the medial femoral condyle, 88% had a good or excellent result, 85% for the lateral femoral condyle and 80% for the patella. 61 patients were arthroscopically assessed at one year. 50/61 (82%) demonstrated ICRS grade 1 or 2 repair. Healing of the defect occurred with either a periosteum or chondrogide defect cover. Results at one year suggest that ACI is a successful articular cartilage repair technique in selected patients. Long-term follow-up is required to assess the durability of the repair.