Introduction. Insufficient arthroscopic cuff tear reconstruction leading to massive osteoarthritis and irreparable rotator cuff tears might be salvaged by implantation of an inverted total shoulder prosthesis Delta in the elderly. However, despite the generally high success rate and satisfying clinical results of inverted total shoulder arthroplasty, this treatment option has potential complications. Therefore, the objective of this study was a prospective evaluation of the clinical and radiological outcome after a minimum of 2 years follow-up of patients undergoing inverted shoulder replacement with or without prior rotator cuff repair. Patients and Methods. Sixty-eight shoulders in 66 patients (36 women and 30 men) operated between February 2002 and June 2007 with a mean age of 66 years (ranging from 53 to 84 years) were first assessed preoperatively and then at minimum 2 years follow-up, using the Constant score for pain, Constant Shoulder Score, Oxford Shoulder Score, UCLA Shoulder rating scale, DASH Score, Rowe Score for Instability and Oxford Instability Score. 29 patients (Group A) had undergone previous shoulder arthroscopy for cuff tear reconstruction at a mean of 29 months (range 12 to 48 months) before surgery and 39 patients (Group B) underwent primary implantation of an inverted total shoulder prosthesis Delta. Any complications in both groups were assessed according to Goslings and Gouma. Results. We report statistically significant improvements of all obtained scores at a mean follow-up of 42 months (ranging from 24 to 96 months) in both groups. Significant outcome differences between 29 patients with previous shoulder arthroscopy for cuff tear reconstruction and 39 without previous shoulder arthroscopy were not observed. Eight complications occurred altogether, in terms of a nerve lesion once, loosening of the humeral stem three times, and loosening or fracture of the glenoid component four times. Conclusion. We did not detect any statistically significant impact of previous insufficient shoulder arthroscopy for cuff tear reconstruction on the outcome and survival rate after the implantation of the inverted total shoulder prosthesis Delta. We conclude that reverse total shoulder arthroplasty with the Delta prosthesis is significantly beneficial in terms of less shoulder pain, higher stability and gain of range of motion without this beneficial effect being significantly weakened by previous insufficient shoulder arthroscopy for cuff tear reconstruction. We believe that previous arthroscopic cuff tear reconstruction should therefore be included in the treatment algorithm

Failure to treat acute compartment syndrome (ACS) early leads to significant morbidity. Current practice depends on using clinical signs and intracompartmental pressure (ICP) monitoring to diagnose the syndrome but there is still debate regarding their accuracy and interpretation. Patients admitted with injuries at risk of ACS underwent intramuscular (IM) pH and ICP monitoring combined with regular clinical assessment. Fasciotomies were performed on those with clinical and/or pressure based evidence of ACS. All patients were subsequently assessed for evidence of a missed ACS at at 6 & 12 months. Of the 62 patients, 51 completed the protocol and were included in the analysis. They were divided into 2 groups: those who had ACS, either initially (fasciotomies; 13), or diagnosed at follow up (no fasciotomies; 7), and those with no evidence of ACS (31). The sensitivity and specificity for the worst values for each variable were calculated and receiver operator characteristic (ROC) curves generated. The area under the curve for pH was 0.92, 0.73 for absolute pressure and 0.59 for delta pressure. To achieve a sensitivity of 95%, an absolute pressure of >30mmHg was 30% specific, a delta pressure of <33mmHg was 27%, while IM pH of 6.38 was 80% specific. This study highlights the issues concerning current diagnostic methods for ACS. By comparison, IM pH radically out performed both the highest ICP and the lowest delta pressure, identifying patients early and accurately

Aims

Prior to the availability of vaccines, mortality for hip fracture patients with concomitant COVID-19 infection was three times higher than pre-pandemic rates. The primary aim of this study was to determine the 30-day mortality rate of hip fracture patients in the post-vaccine era.

Due to increased life expectancy of human population, the amount of total knee replacements (TKR) is expected to increase. TKR reached a high grade of quality and safety, but most often it fail because of aseptic implant loosening caused by polyethylene (PE) wear debris. Wear is generated at the articulating surfaces, e.g. caused by three body particles, like bone fragments or bone cement particles. The aim of this experimental study was to compare the wear of tibial PE inserts combined with metallic and ceramic femoral components at three body wear situation induced by polymethylmethacrylate (PMMA) and zirconia (ZrO2) particles from the bone cement. Wear testing was performed for 5 Mio load cycles, using tibial standard PE inserts combined with the same CR femoral component, in two different materials, Cobalt Chromium (CoCrMo) and Biolox delta ® ceramic (Multigen Plus Knee System, Lima Corporate, Italy). A knee wear simulator, according to ISO 14243 (EndoLab GmbH, Rosenheim, Germany), was used to carry out the tests. The tests were performed in temperature-controlled test chambers at 37 °C, containing calf serum with a protein content of 30 g/l. Polymethylmethacrylate (PMMA) and zirconia (ZrO2) bone cement particles (Palacos R ®) were manufactured to a size of 30 μm. The three body particles were added at all stations onto the articulating surface of the tibial PE insert (7mg per condyle) at every 500,000 cycles. Wear was determined gravimetrically and the surfaces of tibial inserts were analysed by scanning electron microscope (SEM) after finishing the 5 million cycles. Furthermore, roughness of the PE insert surfaces and the articulating surfaces of the different femoral components were detected and the PE wear particles were analysed by SEM. The average gravimetrical wear rates of the tibial PE inserts in combination with CoCr and Biolox delta ® ceramic femoral components amounted to 6.4 ± 0.9 mg and 2.6 ± 0.4 mg per million cycles, respectively. Beside bone cement particles on the articulating surface of the PE inserts, polished surfaces and scratches were detected by SEM. In comparison to the untreated surfaces of the PE inserts at both material pairings the surface roughness at the articulating areas showed deep scratches and polished regions. Analyses of the metallic femoral components showed scratches at the articulating surfaces, none on ceramics. The present study pointed out the effect of femoral component material in an abrasive three body wear situation on the wear properties of TKR. The wear simulator tests showed that wear of PE inserts under three body wear conditions, in combination with ceramic femoral components, was significantly lower than with metallic femoral components. With regard to anti-allergic properties, ceramic femoral components are promising products for TKR

Purpose. to analyze the survivorship of the RSA with a minimum 10 years follow up. Patients and Methods. Between 1992 and 1999, 145 Delta (DePuy) RSAs have been implanted in 138 patients. It was a mulicentric study. Initial etiologies were gathered as following: group A (92 cases) Cuff tear arthropaties (CTA), osteoarthritis (OA) with at least 2 involved cuff tendons, and massive cuff tear with pseudoparalysis (MCT); group B (39 cases) -failed hemiarthroplasties (HA), failed total shoulder arthroplasties (TSA), and fracture sequelae; and group C (14 cases) rheumatoid arthritis, fractures, tumor, and instability. Survival curves were established with the Kaplan-Meier technique. Two end-points were retained: -implant revision, defined by glenoid or humeral replacement or removal, or conversion to HA; - a poor clinical outcome defined by an absolute Constant score of less than 30. Results. At the time of review, 47 patients had died with their prosthesis in place and 30 were lost to follow-up. There were 12 revisions, 6 for infections, 3 for glenoid loosening, 1 for dislocation, 1 for glenoid dissociation (by unscrewing), and 1 for humeral loosening. The survival curve to prosthetic removal showed an overall survivorship of 92% at 10 years. Segmentation according to etiology showed a 97% survivorship for group A and 88% for group B This difference was not significant. No patients of group C had a minimum follow up of ten years because there were died or lost to follow up. The survival curve to a Constant score of less than 30 showed an overall survivorship of 90% at 10 years. Segmentation according to etiology showed a significant difference at 10 years in favor of group A (92%) compared to group B (86%) with a break of the curve after 9 years for group B. Discussion. Our results show that the overall survivorship of the reverse shoulder prosthesis to removal is good even 10 years after implantation, in particular if it had been implanted for CTA, OA, or MCT. However, functional results did deteriorate progressively after 9 years in particular if it had been implanted for revision (HA or TSA). Therefore, extreme caution must be observed in relation to the indications for reverse shoulder arthroplasty, especially in younger patients

INTRODUCTION. Ceramic-on-metal hip replacements (COM, where the head is a Biolox Delta ceramic and liner is Co Cr alloy), have demonstrated reduced wear under standard conditions in vitro compared to metal-on-metal (MOM) [1]. Early clinical results are also encouraging [2]. Recently concerns have been raised regarding the poor clinical performance of MOM hip resurfacings [3], particularly when cups are steeply inclined. Laboratory hip simulator testing has been used to replicate edge loading, also demonstrating elevated wear [4]. Therefore, a range of conditions to replicate sub-optimal use clinically to better predict in vivo performance should be used. The aim of this study was to compare the wear rates of MOM and COM under adverse edge loading conditions in an in vitro hip simulator test. METHODS. Ceramic-on-metal (n=3) and metal-on-metal (n=3) 36mm hip prostheses (supplied by DePuy International Ltd, UK) were tested in the Leeds Physiological Anatomical Hip Joint Simulator. Liners were mounted to provide a clinical angle of 45o, and stems positioned anatomically. A simplified gait cycle and microseparation was applied as previously described [5] for two million cycles in 25% new born calf serum. Gravimetric analysis was completed every million cycles and wear volumes calculated. RESULTS. The overall mean volumetric wear rate of COM bearings was 0.36 ± 0.55mm3 per million cycles, this was significantly less than the MOM bearing wear (1.32 ± 0.91mm3 per million cycles). For both COM and MOM bearings wear under these edge loading conditions was significantly greater if compared to previously reported wear under standard conditions [1]. DISCUSSION. The reduced wear of COM has been attributed to the differential hardness decreasing adhesive wear and reduced corrosive wear [6]. Wear under the harsh edge-loading conditions in this study is also reported to be significantly less in COM bearings compared to MOM. In MOM bearings in edge contact conditions, the wear zone becomes starved of lubrication, this elevates wear and increases damage at the edge of the cup. In COM bearings the harder head does not become damaged when there is lubricant starvation and hence wear does not accelerate in the same way. In conclusion, COM bearings show reduced wear compared to MOM bearings under standard and adverse conditions and there is some early evidence to support this finding clinically. ACKNOWLEDGEMENTS. Supported by DePuy International Ltd. SW is supported by a Royal Academy of Engineering/EPSRC (UK) fellowship

Introduction. In total hip arthroplasty ceramic on ceramic bearing couples are used more and more frequently and on a wordwide basis. The main reason of this choice is reduction of wear debris and osteolysis. The tribological properties and the mechanical behaviour of the implanted ceramic must remain the same throughout the patient's life. The aim of this study was to evaluate the resistance of Alumina Matrix Composite to environmental degradation. Material and method. The alumina matrix composite or BIOLOX ® delta is manufactured in Germany by CeramTec. It is made up of 80 vol.% Al2O3, 17 vol.% Yttria Stabilized ZrO2 and 3vol.% strontium aluminate platelets. The zirconia grains account for 1.3 mol.% of the Yttria content. Accelerated aging tests in water steam at 142°C, 134°C, 121°C, and 105°C were performed to evaluate the aging kinetics of the composite. X-ray diffraction was used to determine the monoclinic phase content on the material surface. Phase transformation is associated with weakness and increase in roughness of zirconia ceramic implants. Results. The data below shows average monoclinic contents before and after aging in water vapour according to the ISO standard test (134°C, 2 bars water steam, 10 h) on the surface and inside the 28 mm taper(12/14 taper) femoral ball heads manufactured in alumina ceramic composite. There are precisions concerning the roughness and the load to failure before and after aging concerning 28mm diameter heads. Before Aging 13%+/-3% of Monoclinic content. After 10 H at 134°C23%+/-3% of Monoclinic content the roughness of the polished surface remain the same (5nm+/− 2). The load to failure of 28 mm heads before aging is 76 kN +/− 5kN, and 72 kN +/− 5kN after aging. The results show that although a rise in monoclinic content is predictable after long aging duration in vivo, the impact of the transformation is quite different to monolithic zirconia. A zirconia femoral head exhibits an important increase of roughness from 2 nm to more than 50 nm when submitted to the same duration of ageing. Other tests with hip simulators under severe micro separation have been done to analyse the impact of aging on wear performance. The main wear zone on femoral heads underwent a phase transformation from tetragonal to monoclinic (23% monoclinic) at 5 milion cycles duration without any change in roughness after 5Mc duration. Conclusion. This experimental testing program has enabled a prediction for the long-term in vivo environmental resistance of prostheses made out of Alumina Matrix Composite. The substantial improvement in mechanical properties and the excellent wear behaviour, even under severe microseparation conditions has been clinically confirmed. Today more than 960,000 ceramic ball heads and more than 450 000 ceramic inserts made of the alumina matrix composite have been implanted. Additionally, due to enhanced mechanical behaviour, new applications in orthopaedics are possible

We used an inverted shoulder arthroplasty in 43 consecutive patients with a mean age of 78 years (65 to 97) who had sustained a three- or four-part fracture of the upper humerus. All except two were reviewed with a mean follow-up of 22 months (6 to 58).

The clinical outcome was satisfactory with a mean active anterior elevation of 97° (35° to 160°) and a mean active external rotation in abduction of 30° (0° to 80°). The mean Constant and the mean modified Constant scores were respectively 44 (16 to 69) and 66% (25% to 97%). Complications included three patients with reflex sympathetic dystrophy, five with neurological complications, most of which resolved, and one with an anterior dislocation. Radiography showed peri-prosthetic calcification in 36 patients (90%), displacement of the tuberosities in 19 (53%) and a scapular notch in ten (25%). Compared with conventional hemiarthroplasty, satisfactory mobility was obtained despite frequent migration of the tuberosities. However, long-term results are required before reverse shoulder arthroplasty can be recommended as a routine procedure in complex fractures of the upper humerus in the elderly.